Background

The relationship between postoperative adverse events and blood pressures in the preoperative period remains poorly understood. This study tested the hypothesis that day-of-surgery preoperative blood pressures are associated with postoperative adverse events.

Methods

The authors conducted a retrospective, observational study of adult patients having elective procedures requiring an inpatient stay between November 2017 and July 2021 at Vanderbilt University Medical Center to examine the independent associations between preoperative systolic and diastolic blood pressures (SBP, DBP) recorded immediately before anesthesia care and number of postoperative adverse events—myocardial injury, stroke, acute kidney injury, and mortality—while adjusting for potential confounders. The study used multivariable ordinal logistic regression to model the relationship.

Results

The analysis included 57,389 cases. The overall incidence of myocardial injury, stroke, acute kidney injury, and mortality within 30 days of surgery was 3.4% (1,967 events), 0.4% (223), 10.2% (5,871), and 2.1% (1,223), respectively. The independent associations between both SBP and DBP measurements and number of postoperative adverse events were found to be U-shaped, with greater risk both above and less than SBP 143 mmHg and DBP 86 mmHg—the troughs of the curves. The associations were strongest at SBP 173 mmHg (adjusted odds ratio, 1.212 vs. 143 mmHg; 95% CI, 1.021 to 1.439; P = 0.028), SBP 93 mmHg (adjusted odds ratio, 1.339 vs. 143 mmHg; 95% CI, 1.211 to 1.479; P < 0.001), DBP 106 mmHg (adjusted odds ratio, 1.294 vs. 86 mmHg; 95% CI, 1.003 to 1.17671; P = 0.048), and DBP 46 mmHg (adjusted odds ratio, 1.399 vs. 86 mmHg; 95% CI, 1.244 to 1.558; P < 0.001).

Conclusions

Preoperative blood pressures both less than and above a specific threshold were independently associated with a higher number of postoperative adverse events, but the data do not support specific strategies for managing patients with low or high blood pressure on the day of surgery.

Editor’s Perspective
What We Already Know about This Topic
  • A diagnosis of hypertension is a risk factor for many adverse cardiovascular events

  • Among patients with or without a diagnosis of hypertension, the specific day of surgery blood pressure thresholds that are associated with adverse events remain poorly studied

What This Article Tells Us That Is New
  • Electronic health record data demonstrated that among 57,389 patients studied at a single center, the overall incidence of myocardial injury, stroke, acute kidney injury, and mortality within 30 days of surgery was 3.4% (1,967 events), 0.4% (223), 10.2% (5,871), and 2.1% (1,223)

  • Systolic blood pressures above and less than 143 mmHg and diastolic blood pressures above and less than 86 mmHg were associated with a higher risk of these adverse events

  • Acute kidney injury demonstrated the most reproducible and reliable association with higher or lower preoperative blood pressure

Chronic hypertension is a common comorbidity among surgical patients.1,2  Poorly controlled hypertension may damage organs, including the heart, brain, and kidneys.3–5  This resulting organ dysfunction may not be clinically evident to patients and is often undiagnosed before the day of surgery.6,7  Thus, patients with chronic hypertension are at increased risk of postoperative complications, including acute kidney injury (AKI),8,9  myocardial injury,10  and stroke.11  Furthermore, preinduction elevated blood pressures may predispose to intraoperative hemodynamic instability12,13  and exaggerated hemodynamic responses to pain and inflammation.14  These factors may all contribute to an increased risk of perioperative cardiovascular complications.15 

The American College of Cardiology (Washington, D.C.) and American Heart Association (Dallas, Texas) provide evidence-based guidelines and algorithms for evaluating and managing perioperative comorbidities, including coronary artery disease, heart failure, valvular heart disease, and arrhythmias.16  Recent guidelines on the management of chronic hypertension3  include a brief mention of perioperative management. However, the recommendations are less specific than for the above conditions, and supporting evidence is not as robust. The authors mention consideration of canceling surgery when blood pressure measurements are greater than 180/110 mmHg, a recommendation echoed by various European guidelines.3,17–19  This recommendation, however, is based largely on older observational data and expert opinion.4,12,20,21  One consensus statement concludes that “there is insufficient evidence to recommend a specific threshold of blood pressure upon which to decide whether or not to proceed with surgery, unless the extreme arterial pressure is associated with a medical emergency.”19 

In a 2017 study, Venkatesan et al. demonstrated a relationship between preoperative blood pressure values and adverse perioperative outcomes, but the risk was based on outpatient clinic blood pressures rather than preinduction or day-of-surgery measurements.22  Several unique factors may impact a patient’s blood pressure on the day of surgery, such as temporary discontinuation of antihypertensive medications, anxiety, pain, or new-onset hypertension. Elucidating the association between preoperative day-of-surgery blood pressure values and postoperative complications may guide safe perioperative management of patients. Therefore, we sought to evaluate the association between preoperative blood pressures and adverse cardiac, cerebral, and renal events in the postoperative period. Specifically, we hypothesized that elevated preoperative blood pressure measurements on the day of surgery before induction of anesthesia are associated with postoperative adverse events, including stroke, myocardial injury, acute kidney injury, and mortality within 30 days after surgery.

The Vanderbilt University Medical Center Institutional Review Board (IRB; Nashville, Tennessee) approved this study with a waiver of written informed patient consent (IRB No. 211596). The Strengthening the Reporting of Observational Studies in Epidemiology statement23  was used to report this study, and the manuscript adheres to the applicable guidelines. The data analysis and statistical plan were written and filed with the IRB before data were accessed.

We conducted a retrospective cohort study using information from electronic health records at the Vanderbilt University Medical Center Perioperative Data Warehouse. We included adult patients (18 yr or older) receiving anesthesia for noncardiac surgery and medical procedures between November 2, 2017 (the go-live date of our Epic electronic health record installation), and July 15, 2021. We excluded patients who (1) required emergency surgery, (2) did not spend at least 1 night in the hospital, (3) had an American Society of Anesthesiologists (ASA; Schaumburg, Illinois) Physical Status classification score of VI, or (4) had a documented systolic blood pressure (SBP) greater than 300 mmHg or less than 20 mmHg or a diastolic blood pressure (DBP) greater than 200 mmHg or less than 20 mmHg due to the implausibility of these measurements, as documented in previous literature24  (fig. 1).

Fig. 1.

Consolidated Standards of Reporting Trials (CONSORT) diagram. ASA, American Society of Anesthesiologists.

Fig. 1.

Consolidated Standards of Reporting Trials (CONSORT) diagram. ASA, American Society of Anesthesiologists.

Close modal

Primary Exposure and Outcome

The primary exposures of interest were the preoperative SBP and DBP measurements. We used the last pressure readings recorded in the preoperative holding area just before commencement of anesthesia care. In cases where the preoperative holding area measurements were not available, we used the first blood pressure measurement documented in the anesthesia record before induction of anesthesia.

The primary outcome was defined as the number of postoperative adverse events, including myocardial injury, stroke, AKI, and mortality within 30 days of surgery. While myocardial injury, stroke, and AKI each counted as one event in the scoring system, any patient who died was assigned a total score of 4 points. Therefore, the primary outcome was scored from 0 to 4. Myocardial injury was defined as troponin I 0.04 ng/ml or greater, consistent with the Fourth Universal Definition of Myocardial Infarction.25  Postoperative stroke was identified as patients with a combination of a code stroke alert, any new computerized tomography of the head, and International Classification of Diseases, Tenth Revision, diagnosis of stroke documented in the medical record. Patients had to have all three of these criteria. This combination was chosen because diagnosis in the medical record alone may include strokes before surgery, and computerized tomography of the head may be part of routine care, particularly for neurosurgical patients. The code stroke initiation identified patients suspected of having an acute stroke. No manual review of diagnostic testing results or electronic health record notes was performed to confirm the occurrence of a postoperative stroke. Postoperative AKI was defined by criteria from the Kidney Disease: Improving Global Outcomes guidelines26 : increase in serum creatinine by 0.3 mg/dl or greater within 48 h or increase in serum creatinine to 1.5 or more times baseline, which is known or presumed to have occurred within the previous 7 days. Definition of AKI based on urine output was not included due to the unreliability of postoperative urine output measurement. Patients with end-stage renal disease were not considered to be eligible for AKI occurrence. End-stage renal disease was defined as preoperative renal replacement therapy or preoperative glomerular filtration rate less than 15. Patients in whom no troponin or serum creatinine was measured in the postoperative period were treated as not incurring postoperative myocardial injury and AKI, respectively. Finally, mortality data were ascertained only from documentation in the electronic health record.

We collected the following covariates from the electronic health record: age, sex, race, van Walraven score (a comprehensive measure to predict in-hospital mortality),27,28  each of the 31 Elixhauser comorbidities29  included in the van Walraven score (see table, Supplemental Digital Content 1, https://links.lww.com/ALN/D513, for examples of comorbidities and specific International Classification of Diseases, Tenth Revision, codes), ASA Physical Status classification score, duration of surgery, surgical or procedural service, ASA base units, coronary artery disease (diagnosed before surgery), and preoperative cerebrovascular disease (diagnosed before surgery).

Statistical Analysis

We characterized the study population by reporting demographic, clinical, and procedural data with means ± SDs for parametric variables, with medians and interquartile ranges for nonparametric variables, and with percentages for categorical variables.

We conducted two primary analyses using multivariable ordinal logistic regression to assess the association between preoperative SBP or DBP measurements and the odds of experiencing a higher number of postoperative adverse events (myocardial injury, stroke, AKI, and mortality) within 30 days after surgery. We a priori included patient age, sex, race, all Elixhauser comorbidities, ASA Physical Status classification score, and duration of surgery as potential covariates in the regression. A least absolute shrinkage and selection operator approach was then applied to identify covariates for inclusion in the final model. In response to peer review, complicated hypertension,29  anesthesia base units (assigned value by the ASA for each Current Procedural Terminology code, which considers the complexity, risk, and skill required to perform the service),30  surgical or procedural service (“non–operating room anesthesia” service as defined by Dabu-Bondoc’s review on the topic31 ), preoperative coronary artery disease, and preoperative cerebrovascular disease were also included in the final model. We used restricted cubic splines with five knots at the 5th, 35th, 50th, 65th, and 95th percentiles to flexibly model the association of preoperative SBP or DBP with the primary outcome. The associations were then summarized using the ordinal adjusted odds ratios and 95% CIs, in comparison to the blood pressure with the lowest estimated risk, and tested using the Wald multiple degree of freedom chi-square test. The adjusted odds ratio is interpreted as the fold-change in the odds of a higher number of postoperative adverse events (1 vs. 0, 2 vs. 1, 3 vs. 2, or 4 vs. 3) associated with the primary exposure variables or with the covariates, after controlling for all the other covariates. The proportional odds assumption was examined using the chi-square score test, and the goodness of fit was measured with c-statistics. The E value was calculated to quantify the potential impact of unmeasured confounding.

We performed several prespecified and post hoc secondary analyses. They were all summarized in the same manner: the blood pressures with the lowest estimated risk were identified, and the ordinal adjusted odds ratios (with 95% CIs) were calculated per each 10-mmHg change in blood pressure away from those “lowest risk” pressures. In the first prespecified sensitivity analysis, we eliminated cases of mortality within 30 days of surgery from the data set to evaluate the significance of mortality as a competing variable. We also performed a multivariable logistic regression to evaluate the association between preoperative SBP values and a composite outcome of myocardial injury, stroke, and AKI within 30 days of surgery. Finally, three separate sensitivity analyses were performed to model the association between preoperative SBP values and each individual outcome (myocardial injury, stroke, and AKI within 30 days after surgery) to assess the impact of one or more of the individual outcomes on the primary outcome measure. For the post hoc analyses, we first restricted the SBP analysis to patients with a preoperative diagnosis of hypertension. This was done because abnormal preoperative blood pressure measurements in these patients may be assessed differently by clinicians compared to those patients with no known history of hypertension. To minimize the bias during the knot selection for regression splines, we also conducted a sensitivity analysis of preoperative SBP values on postoperative adverse events using the generalized additive model approach. Next, we performed an analysis eliminating all cases from the primary analysis where the preoperative SBP value was outside of the median 99% of the data range to help ascertain if extreme values with a higher probability of being measurement errors were significantly affecting the analysis. We then performed a multivariable analysis to assess the effect of preoperative pulse pressure on the odds of experiencing a higher number of postoperative adverse events. Finally, we resummarized the primary SBP analysis in the same manner as the sensitivity and subgroup analyses for the sake of ease of comparison.

A two-sided P value of less than 0.05 was considered to indicate statistical significance. Statistical programming was implemented in SAS 9.4 (SAS Institute Inc., USA) and R (R Foundation for Statistical Computing; Vienna, Austria; version 3.6.1; Hmisc, lme4, and rms packages installed).

We screened 133,438 anesthetics that occurred between November 2, 2017, and July 15, 2021. We excluded 152 cases with an ASA Physical Status score of VI, 68,593 cases where patients did not spend at least 1 night in the hospital, and 31 cases with a documented SBP greater than 300 mmHg or less than 20 mmHg or DBP greater than 200 mmHg or less than 20 mmHg (fig. 1). We included 57,389 cases in the final analysis. Patients had a mean ± SD age of 54.7 ± 16.9 yr, and 48.0% were male. The median preoperative SBP was 131 mmHg (interquartile range, 118 to 145). The median preoperative DBP was 77 mmHg (interquartile range, 66 to 85). A total of 53,329 cases did not have a postoperative troponin measurement, and 12,861 cases did not have a postoperative serum creatinine measurement. The incidence of myocardial injury, stroke, AKI, and mortality within 30 days of surgery was 3.4% (1,967 events), 0.4% (223), 10.2% (5,871), and 2.1% (1,223), respectively. Detailed patient characteristics are listed in table 1.

Table 1.

Demographic Characteristics of the Study Sample

Demographic Characteristics of the Study Sample
Demographic Characteristics of the Study Sample

From the results of the primary analysis, the relationship between SBP and the primary outcome (number of postoperative adverse events) was found to be U-shaped, with an increased risk of a higher number of postoperative adverse events (1 vs. 0, 2 vs. 1, 3 vs. 2, or 4 vs. 3) both above and less than SBP 143 mmHg—the trough of the curve where risk was minimal (table 2; fig. 2). The association was highest at a SBP of 173 mmHg, where the adjusted odds ratio was 1.212 as compared to SBP 143 mmHg (95% CI, 1.021 to 1.439; P = 0.028), and at a SBP of 93 mmHg where the adjusted odds ratio was 1.339 as compared to SBP 143 mmHg (95% CI, 1.211 to 1.479; P < 0.001). At the extreme ends of the curve, there were very few data points at each blood pressure value, and the relationship between SBP and the primary outcome was uncertain. Meanwhile, the following were associated with increased odds of a higher number of postoperative adverse events (AKI, myocardial injury, stroke, mortality): older patient age (adjusted odds ratio, 1.137 [per 10 yr]; 95% CI, 1.116 to 1.158; P < 0.001), male sex (adjusted odds ratio, 1.066; 95% CI, 1.009 to 1.126; P = 0.022), higher ASA Physical Status score (adjusted odds ratio, 1.393 [per 1 point]; 95% CI, 1.322 to 1.467; P < 0.001), longer operative time (adjusted odds ratio, 1.080 [per 1 h]; 95% CI, 1.066 to 1.094; P < 0.001), preoperative coronary artery disease (adjusted odds ratio, 1.095; 95% CI, 1.017 to 1.180; P = 0.017), seven surgical or procedural services, and 17 Elixhauser comorbidities (table 2). Of note, covariate effects represent causal direct effects only if all confounders of these associations are controlled.23  The c-statistic of multivariable logistic regression was 0.80. The E value was 1.17 (Supplemental Digital Content 2, https://links.lww.com/ALN/D514).

Table 2.

Analysis of the Association of Preoperative Systolic Blood Pressures with the Occurrence of a Higher Number of Postoperative Adverse Events (Acute Kidney Injury, Myocardial Injury, Stroke, and Mortality) within 30 Days after Surgery

Analysis of the Association of Preoperative Systolic Blood Pressures with the Occurrence of a Higher Number of Postoperative Adverse Events (Acute Kidney Injury, Myocardial Injury, Stroke, and Mortality) within 30 Days after Surgery
Analysis of the Association of Preoperative Systolic Blood Pressures with the Occurrence of a Higher Number of Postoperative Adverse Events (Acute Kidney Injury, Myocardial Injury, Stroke, and Mortality) within 30 Days after Surgery
Fig. 2.

Spline graph for the association between preoperative systolic blood pressures and the log odds of incurring a higher number of postoperative adverse events (myocardial injury, stroke, acute kidney injury, mortality), adjusted for 25 covariates. Associated histogram depicts the number of patients at each systolic blood pressure measurement.

Fig. 2.

Spline graph for the association between preoperative systolic blood pressures and the log odds of incurring a higher number of postoperative adverse events (myocardial injury, stroke, acute kidney injury, mortality), adjusted for 25 covariates. Associated histogram depicts the number of patients at each systolic blood pressure measurement.

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A similar U-shaped relationship was found between DBP and the primary outcome (table 3; fig. 3). Here, the trough of the curve associated with minimal risk was 86 mmHg, with greater odds of experiencing a higher number of postoperative adverse events (1 vs. 0, 2 vs. 1, 3 vs. 2, or 4 vs. 3) both above and less than this value. At a DBP of 106 mmHg, the adjusted odds ratio for a higher number of postoperative adverse events was 1.294 as compared to 86 mmHg (95% CI, 1.003 to 1.17671; P = 0.048), and at a DBP of 46 mmHg, the adjusted odds ratio was 1.399 as compared to DBP 86 mmHg (95% CI, 1.244 to 1.558; P < 0.001). The E value was 1.28 (Supplemental Digital Content 3, https://links.lww.com/ALN/D515).

Table 3.

Analysis of the Association of Preoperative Diastolic Blood Pressures with the Occurrence of a Higher Number of Postoperative Adverse Events (Acute Kidney Injury, Myocardial Injury, Stroke, and Mortality) within 30 Days after Surgery

Analysis of the Association of Preoperative Diastolic Blood Pressures with the Occurrence of a Higher Number of Postoperative Adverse Events (Acute Kidney Injury, Myocardial Injury, Stroke, and Mortality) within 30 Days after Surgery
Analysis of the Association of Preoperative Diastolic Blood Pressures with the Occurrence of a Higher Number of Postoperative Adverse Events (Acute Kidney Injury, Myocardial Injury, Stroke, and Mortality) within 30 Days after Surgery
Fig. 3.

Spline graph for the association between preoperative diastolic blood pressures and the log odds of incurring a higher number of postoperative adverse events (myocardial injury, stroke, acute kidney injury, mortality), adjusted for 26 covariates. Associated histogram depicts the number of patients at each diastolic blood pressure measurement.

Fig. 3.

Spline graph for the association between preoperative diastolic blood pressures and the log odds of incurring a higher number of postoperative adverse events (myocardial injury, stroke, acute kidney injury, mortality), adjusted for 26 covariates. Associated histogram depicts the number of patients at each diastolic blood pressure measurement.

Close modal

Table 4 provides a summary of comparison among the sensitivity and subgroup analyses. In the prespecified sensitivity analyses excluding the competing event of 30-day mortality, we found that preoperative SBP was associated with both the ordinal outcome of number of postoperative adverse events (table 4; Supplemental Digital Content 4, https://links.lww.com/ALN/D516) and the binary composite outcome of the postoperative adverse events (table, Supplemental Digital Content 5, https://links.lww.com/ALN/D517; table 4). A U-shaped distribution similar to the primary analysis was observed, although the odds ratios were lower than in the primary analysis. The three separate sensitivity analyses of the relationship between SBP and the individual postoperative adverse events revealed a statistically significant association between SBP and AKI (table 4; Supplemental Digital Content 6, https://links.lww.com/ALN/D518) but not myocardial injury (table 4; Supplemental Digital Content 7, https://links.lww.com/ALN/D519) or stroke (table 4; Supplemental Digital Content 8, https://links.lww.com/ALN/D520). Spline plots depicting all of the sensitivity analyses can be found in Supplemental Digital Content 9 (https://links.lww.com/ALN/D521).

Table 4.

Summary of the Sensitivity and Subgroup Analyses

Summary of the Sensitivity and Subgroup Analyses
Summary of the Sensitivity and Subgroup Analyses

Several post hoc analyses were also performed. Preoperative SBP was still found to be associated with the primary outcome after restricting the analysis to the subgroup of patients with a preoperative diagnosis of hypertension, although the effect size estimates were lower (table 4; Supplemental Digital Content 10, https://links.lww.com/ALN/D522). When considering the relationship between preoperative SBP and postoperative adverse events using the generalized additive model approach, the effect estimates of covariates did not substantially change (Supplemental Digital Content 11, https://links.lww.com/ALN/D523). Similarly, after eliminating cases where the preoperative SBP did not fall within the median 99%, we found a similar U-shaped relationship (table 4; Supplemental Digital Content 12, https://links.lww.com/ALN/D524). Finally, the relationship between pulse pressure and number of postoperative adverse events was found to be significant, with increased risk at higher pulse pressures (greater than 67 mmHg; Supplemental Digital Content 13, https://links.lww.com/ALN/D525).

In patients undergoing noncardiac surgery and procedures, we observed a U-shaped risk-adjusted association between day-of-surgery preoperative systolic and diastolic blood pressures and the number of postoperative adverse events including myocardial injury, stroke, AKI, and mortality. Specifically, in the primary analysis including patients with and without chronic hypertension, there was a higher risk of experiencing the primary outcome with preoperative SBP measurements moving further above and less than 143 mmHg and with DBP measurements moving further above and less than 86 mmHg. This statistically significant association remained in a variety of sensitivity analyses (table 4), but many of the odds ratios were attenuated and may have limited clinical significance. When the association of preoperative SBP with each individual postoperative morbidity was assessed, myocardial injury and stroke no longer demonstrated a statistically significant association with preoperative SBP; only the association with AKI was observed. Finally, consistent with previous data,32  preoperative pulse pressure was found to be associated with postoperative adverse events.

Previous studies have shown that a diagnosis of chronic hypertension is a risk factor for adverse perioperative outcomes,12,20  and that there are specific blood pressure measurement thresholds that are correlated with postoperative morbidity and mortality.22,33  Our study advances our understanding by demonstrating that among patients with or without a diagnosis of chronic hypertension, there is an association between day-of-surgery preoperative blood pressure measurements and postoperative cardiovascular morbidity and mortality. The data confirmed that both higher and lower blood pressures, in comparison to the measurements with the lowest risk (143 mmHg systolic, 86 mmHg diastolic), are associated with a greater risk of adverse events.

Of note, sensitivity analyses revealed that preoperative SBP measurements were associated with only AKI, not myocardial injury or stroke. These analyses temper our conclusions, and there are several possible explanations. First, the incidence of AKI was significantly higher than that of stroke or myocardial injury, thereby increasing the statistical power available to detect an association with preoperative SBP. Additionally, the physiology of renal function and blood flow may make the kidney more susceptible to injury due to changes in blood pressure, while the brain, in particular, likely possesses better autoregulation abilities.34 

Our study has several limitations and the conclusions should be viewed in context of these issues. Due to its retrospective, observational nature, we demonstrate only correlation between preoperative systolic and diastolic blood pressures and adverse events, not causation. It is not possible to adjust for every patient characteristic, and the conclusions are still susceptible to unmeasured confounding or confounding by the choice of modeling strategy. Meanwhile, the E values of the primary analysis of DBP and SBP were 1.17 and 1.28, respectively, which implies that relatively little unmeasured confounding is needed to explain away an effect estimate. It is entirely plausible that the associations we observe reflect unmeasured confounding, such as severity of underlying disease, patient factors not available in the electronic health record, or other clinical issues. Next, the effect sizes in the sensitivity analyses were generally lower than in the primary analysis, further hindering the reliability and reproducibility of our observations. The absence of an a priori minimal clinical important difference challenges our ability to assert that the specific odds ratios we observed are clinically significant. Next, we used the van Walraven score and Elixhauser comorbidities to capture many of the patient characteristic confounders. This was done due to the robustness of the model and its predictive value for in-hospital mortality.27,28  Other perioperative prediction models specific to the outcomes studied could have been used instead. A notable potential confounder that was not included in the analysis was use of antihypertensive medications. This information, particularly timing of last dose, is not reliably captured in our electronic health record and is the primary reason for its exclusion. Additionally, not all patients had a postoperative creatinine or troponin measurement. Therefore, some instances of AKI and subclinical myocardial injury were likely missed. We did attempt to minimize this by excluding patients who underwent outpatient surgery. Next, as a single-center analysis, the current work does not provide external validation and may have limited generalizability to other care settings or patients. Finally, while we contend that our method for identifying postoperative strokes was comprehensive (patients had to meet three different criteria), there is the clear possibility of misclassification bias, with some events missed and some that are incorrectly classified as a stroke event.

Previous recommendations concerning specific blood pressure thresholds for canceling elective surgery or altering patient management3,16–19  acknowledge the fact that there are many confounding factors that may independently affect both preoperative blood pressure measurements and perioperative adverse events. These recommendations are hampered by limited data. Unfortunately, the data presented in this manuscript do not offer definitive evidence. Guidelines from the American College of Cardiology and American Heart Association recommend considering cancelation of surgery if preoperative blood pressure is greater than 180/110 mmHg.3  While our study found a concerning association, there is no evidence to definitively support this specific threshold, particularly in the chronic hypertensive population, where the odds ratio for patients with a preoperative SBP of 184 mmHg compared to patients with a SBP of 174 mmHg, for example, was only 1.076. Furthermore, on sensitivity analysis, we found that of the individual components of the primary outcome measure, only AKI was correlated with SBP measurements. Next, when considering cancelation of surgery for either high or low blood pressure measurements, there are many other factors to consider, including etiologies of abnormal blood pressure measurements, how these preoperative measurements compare to patients’ usual blood pressure measurements, the urgency of surgery, and whether cancelation and further assessment and management would actually modify risk, to name a few. Therefore, the results of this study do not allow definitive recommendations regarding canceling elective surgery at specific blood pressure thresholds.

Perhaps the main value of the findings of this study is to generate hypotheses for future research centered on the relationship between day-of-surgery preoperative blood pressure measurements and postoperative adverse events. For example, a prospective trial examining the effect of delaying versus proceeding with elective surgery based on specific, markedly elevated or low blood pressure values in specific populations may help inform decisions about patient care preoperatively on the day of surgery. Another direction of future research that may stem from this study is implementation of strategies to prevent patients from presenting for procedures with significantly elevated or low blood pressure measurements. Given both our findings and the established correlation between blood pressure measured in the preoperative setting and at home,7  detection and management of previously undiagnosed chronic hypertension in surgical patients before the day of surgery could be of great value. Finally, further investigation, some of which is already underway,35,36  may focus on continuing versus withholding specific antihypertensive medications preoperatively in order to optimize day-of-surgery preoperative blood pressure measurements.

Acknowledgments

Mark Garrison, B.A., Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee, Business Intelligence Analyst, assisted with data retrieval; Yvonne Poindexter, M.A., Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, Tennessee, Editor for Anesthesiology Faculty Affairs Office, assisted with proofreading and formatting.

Research Support

This work was supported by grants K23HL148640 (National Heart, Lung, and Blood Institute, Bethesda, Maryland, to Dr. Freundlich) and UL1TR002243 (National Center for Advancing Translational Sciences, Bethesda, Maryland, to Dr. Freundlich).

Competing Interests

Dr. McEvoy is a consultant for Takeda Pharmaceuticals (Tokyo, Japan) and receives royalties from ASER Pain Medicine (Glenview, Illinois). G. Li owns stock in Johnson & Johnson (New Brunswick, New Jersey) and Roche Holding AG (Basel, Switzerland). Dr. Freundlich owns stock in 3M (St. Paul, Minnesota) and has received consulting fees from Phillips Healthcare (Franklin, Tennessee) and Oak Hill Clinical Informatics (Nashville, Tennessee). The other authors declare no competing interests.

  1. Examples of Elixhauser Comorbidity International Classification of Diseases, Tenth Revision, Codes, https://links.lww.com/ALN/D513

  2. E Value for Primary SBP Analysis, https://links.lww.com/ALN/D514

  3. E Value for Primary DBP Analysis, https://links.lww.com/ALN/D515

  4. Sensitivity Analysis—Excluding Mortalities, https://links.lww.com/ALN/D516

  5. Sensitivity Analysis—Composite Outcome, https://links.lww.com/ALN/D517

  6. Sensitivity Analysis—AKI, https://links.lww.com/ALN/D518

  7. Sensitivity Analysis—Myocardial Injury, https://links.lww.com/ALN/D519

  8. Sensitivity Analysis—Stroke, https://links.lww.com/ALN/D520

  9. Spline Graphs for Sensitivity Analyses, https://links.lww.com/ALN/D521

  10. Subgroup Analysis—Hypertension, https://links.lww.com/ALN/D522

  11. Generalized Additive Model, https://links.lww.com/ALN/D523

  12. Median 99% of Data Values, https://links.lww.com/ALN/D524

  13. Preoperative Pulse Pressure, https://links.lww.com/ALN/D525

1.
Dix
P
,
Howell
S
:
Survey of cancellation rate of hypertensive patients undergoing anaesthesia and elective surgery.
Br J Anaesth
2001
;
86
:
789
93
2.
Vazquez-Narvaez
KG
,
Ulibarri-Vidales
M
:
The patient with hypertension and new guidelines for therapy.
Curr Opin Anaesthesiol
2019
;
32
:
421
6
3.
Whelton
PK
,
Carey
RM
,
Aronow
WS
et al
:
2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines.
Circulation
2018
;
138
:
e426
83
4.
Fleisher
LA
:
Preoperative evaluation of the patient with hypertension.
JAMA
2002
;
287
:
2043
6
5.
Casadei
B
,
Abuzeid
H
:
Is there a strong rationale for deferring elective surgery in patients with poorly controlled hypertension?
J Hypertens
2005
;
23
:
19
22
6.
Ayanian
JZ
,
Zaslavsky
AM
,
Weissman
JS
,
Schneider
EC
,
Ginsburg
JA
:
Undiagnosed hypertension and hypercholesterolemia among uninsured and insured adults in the Third National Health and Nutrition Examination Survey.
Am J Public Health
2003
;
93
:
2051
4
7.
Schonberger
RB
,
Nwozuzu
A
,
Zafar
J
et al
:
Elevated preoperative blood pressures in adult surgical patients are highly predictive of elevated home blood pressures.
J Am Soc Hypertens
2018
;
12
:
303
10
8.
Kheterpal
S
,
Tremper
KK
,
Heung
M
et al
:
Development and validation of an acute kidney injury risk index for patients undergoing general surgery: Results from a national data set.
Anesthesiology
2009
;
110
:
505
15
9.
Prowle
JR
,
Forni
LG
,
Bell
M
et al
:
Postoperative acute kidney injury in adult non-cardiac surgery: Joint consensus report of the Acute Disease Quality Initiative and PeriOperative Quality Initiative.
Nat Rev Nephrol
2021
;
17
:
605
18
10.
Puelacher
C
,
Lurati Buse
G
,
Seeberger
D
et al
;
Investigators B-P
:
Perioperative myocardial injury after noncardiac surgery: Incidence, mortality, and characterization.
Circulation
2018
;
137
:
1221
32
11.
Mashour
GA
,
Shanks
AM
,
Kheterpal
S
:
Perioperative stroke and associated mortality after noncardiac, nonneurologic surgery.
Anesthesiology
2011
;
114
:
1289
96
12.
Howell
SJ
,
Sear
JW
,
Foex
P
:
Hypertension, hypertensive heart disease and perioperative cardiac risk.
Br J Anaesth
2004
;
92
:
570
83
13.
Prys-Roberts
C
,
Meloche
R
,
Foex
P
:
Studies of anaesthesia in relation to hypertension. I. Cardiovascular responses of treated and untreated patients.
Br J Anaesth
1971
;
43
:
122
37
14.
Prys-Roberts
C
,
Greene
LT
,
Meloche
R
,
Foex
P
:
Studies of anaesthesia in relation to hypertension. II. Haemodynamic consequences of induction and endotracheal intubation.
Br J Anaesth
1971
;
43
:
531
47
15.
Aronow
WS
:
Management of hypertension in patients undergoing surgery.
Ann Transl Med
2017
;
5
:
227
16.
Fleisher
LA
,
Fleischmann
KE
,
Auerbach
AD
et al
:
2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines.
Circulation
2014
;
130
:
2215
45
17.
Hartle
A
,
McCormack
T
,
Carlisle
J
et al
:
The measurement of adult blood pressure and management of hypertension before elective surgery: Joint Guidelines from the Association of Anaesthetists of Great Britain and Ireland and the British Hypertension Society.
Anaesthesia
2016
;
71
:
326
37
18.
Kristensen
SD
,
Knuuti
J
,
Saraste
A
et al
;
Authors/Task Force Members
:
2014 ESC/ESA guidelines on non-cardiac surgery: Cardiovascular assessment and management: The Joint Task Force on Non-cardiac Surgery: Cardiovascular assessment and management of the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA).
Eur Heart J
2014
;
35
:
2383
431
19.
Sanders
RD
,
Hughes
F
,
Shaw
A
et al
;
Perioperative Quality Initiative-3 Workgroup
:
Perioperative Quality Initiative consensus statement on preoperative blood pressure, risk and outcomes for elective surgery.
Br J Anaesth
2019
;
122
:
552
62
20.
Howell
SJ
,
Sear
YM
,
Yeates
D
,
Goldacre
M
,
Sear
JW
,
Foex
P
:
Risk factors for cardiovascular death after elective surgery under general anaesthesia.
Br J Anaesth
1998
;
80
:
14
9
21.
Howell
SJ
,
Sear
JW
,
Sear
YM
,
Yeates
D
,
Goldacre
M
,
Foex
P
:
Risk factors for cardiovascular death within 30 days after anaesthesia and urgent or emergency surgery: A nested case-control study.
Br J Anaesth
1999
;
82
:
679
84
22.
Venkatesan
S
,
Myles
PR
,
Manning
HJ
et al
:
Cohort study of preoperative blood pressure and risk of 30-day mortality after elective non-cardiac surgery.
Br J Anaesth
2017
;
119
:
174
23.
von Elm
E
,
Altman
DG
,
Egger
M
et al
:
The Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement: Guidelines for reporting observational studies.
Lancet
2007
;
370
:
1453
7
24.
Monk
TG
,
Bronsert
MR
,
Henderson
WG
et al
:
Association between intraoperative hypotension and hypertension and 30-day postoperative mortality in noncardiac surgery.
Anesthesiology
2015
;
123
:
307
19
25.
Thygesen
K
,
Alpert
JS
,
Jaffe
AS
et al
;
Executive Group on behalf of the Joint European Society of Cardiology (ESC)/American College of Cardiology (ACC)/American Heart Association (AHA)/World Heart Federation (WHF) Task Force for the Universal Definition of Myocardial Infarction
:
Fourth universal definition of myocardial infarction (2018).
Circulation
2018
;
138
:
e618
51
26.
Kellum
JA
,
Lameire
N
;
KDIGO AKI Guideline Work Group
:
Diagnosis, evaluation, and management of acute kidney injury: A KDIGO summary (part 1).
Crit Care
2013
;
17
:
204
27.
van Walraven
C
,
Austin
PC
,
Jennings
A
,
Quan
H
,
Forster
AJ
:
A modification of the Elixhauser comorbidity measures into a point system for hospital death using administrative data.
Med Care
2009
;
47
:
626
33
28.
Thompson
NR
,
Fan
Y
,
Dalton
JE
et al
:
A new Elixhauser-based comorbidity summary measure to predict in-hospital mortality.
Med Care
2015
;
53
:
374
9
29.
Elixhauser
A
,
Steiner
C
,
Harris
DR
,
Coffey
RM
:
Comorbidity measures for use with administrative data.
Med Care
1998
;
36
:
8
27
30.
Privratsky
JR
,
Fuller
M
,
Raghunathan
K
et al
:
Postoperative acute kidney injury by age and sex: A retrospective cohort association study.
Anesthesiology
2023
;
138
:
184
94
31.
Dabu-Bondoc
SM
:
Standard procedures in nonoperating room anesthesia.
Curr Opin Anaesthesiol
2020
;
33
:
539
47
32.
Abbott
TEF
,
Pearse
RM
,
Archbold
RA
et al
:
Association between preoperative pulse pressure and perioperative myocardial injury: An international observational cohort study of patients undergoing non-cardiac surgery.
Br J Anaesth
2017
;
119
:
78
86
33.
Wax
DB
,
Porter
SB
,
Lin
HM
,
Hossain
S
,
Reich
DL
:
Association of preanesthesia hypertension with adverse outcomes.
J Cardiothorac Vasc Anesth
2010
;
24
:
927
30
34.
Kurita
T
,
Kawashima
S
,
Morita
K
,
Nakajima
Y
:
Assessment of cerebral and renal autoregulation using near-infrared spectroscopy under normal, hypovolaemic and postfluid resuscitation conditions in a swine model: An observational study.
Eur J Anaesthesiol
2019
;
36
:
531
40
35.
Marcucci
M
,
Painter
TW
,
Conen
D
et al
:
Rationale and design of the PeriOperative ISchemic Evaluation-3 (POISE-3): A randomized controlled trial evaluating tranexamic acid and a strategy to minimize hypotension in noncardiac surgery.
Trials
2022
;
23
:
101
36.
Yang
YF
,
Zhu
YJ
,
Long
YQ
et al
:
Withholding vs. continuing angiotensin-converting enzyme inhibitors or angiotensin receptor blockers before non-cardiac surgery in older patients: Study protocol for a multicenter randomized controlled trial.
Front Med (Lausanne)
2021
;
8
:
654700