To the Editor:—
Rheumatoid arthritis (RA) is a chronic inflammatory disease of unknown etiology. Patients with RA are recognized to have a reduced life expectancy when compared with the general population. Cardiovascular death is a leading cause of mortality in patients with RA; it is responsible for approximately half of the deaths observed in RA cohorts.1Identification of high-risk patients is often difficult because of the frequent absence of traditional cardiac risk factors.2,3We report the case of a patient with long-standing RA who had development of an acute myocardial infarction (MI) in the early postoperative period after multilevel cervical stabilization surgery. We outline the possible etiology of coronary artery disease (CAD) in patients with RA and highlight this important but often overlooked risk factor for perioperative MI.
A 56-yr-old woman was referred for surgical management of two-level cervical subluxation. She had a background history of severe long-standing RA, requiring regular use of nonsteroidal antiinflammatory agents and oral morphine sulfate. The patient was not a smoker and had no personal or family history of ischemic heart disease. Preoperative anesthetic assessment did not reveal any symptoms or signs of cardiovascular disease. An electrocardiogram showed normal sinus rhythm, with no evidence of myocardial ischemia. Anesthesia was induced and maintained using sevoflurane in an air–oxygen mixture. In addition to routine monitoring of the electrocardiogram, noninvasive blood pressure, and oxygen saturation, peripheral arterial and central venous catheters were inserted for invasive hemodynamic monitoring. The surgical procedure was uneventful, and the patient remained hemodynamically stable throughout. Postoperatively, she was transferred to the intensive care unit for continued ventilation and invasive monitoring. Three hours after surgery, she had development of a sinus tachycardia of 150 beats/min, which was successfully treated with intravenous metoprolol. Twelve hours after surgery, the patient’s trachea was extubation uneventfully. On the second postoperative day, 33 h after surgery, her condition deteriorated abruptly, with acute onset of tachycardia, dyspnea, and oxygen desaturation. At this time, an electrocardiogram revealed atrial fibrillation with ST-segment elevation in both inferior and anterior chest leads. Acute MI was confirmed by an increased troponin concentration of 0.27 μg/l (reference range ≪ 0.01 μg/l) and transthoracic echocardiogram, which showed inferior and apical hypokinesia. After a thorough discussion of benefit versus risk of therapy, systemic thrombolysis was administered. There were no complications associated with the thrombolytic therapy. The patient subsequently made an uneventful recovery, without any further cardiac or neurologic complications. A coronary angiogram performed 10 weeks later did not reveal significant coronary artery stenosis. At 6 months’ follow-up, the patient remains well and continues β-blockade therapy.
Rheumatoid arthritis is a chronic inflammatory disease of unknown etiology, associated with long-term disability and a requirement for frequent anesthesia for orthopedic operative interventions. Patients with RA have a reduced life expectancy associated with extraarticular systemic comorbidities.3,4Several recent large epidemiologic studies have found significantly increased cardiovascular mortality in RA patients as compared with age- and sex-matched controls.2,5Women who had a history of RA of longer than 10 yr were found to be at significantly increased risk of fatal and nonfatal MI.6,7The major independent risk factors for CAD include cigarette smoking, hypertension, diabetes, increased serum cholesterol, family history of CAD, and advanced age.8However, it is being increasingly recognized that traditional risk factors for CAD do not wholly explain the high incidence of cardiovascular events in patients with RA.9Standard clinical assessment may underestimate the prevalence of comorbid CAD in RA.10Assessment of traditional risk factors was negative in this patient.
Although frequently due to coronary atherosclerosis, MI occurring in RA may arise due to coronary artery vasculitis with associated thrombosis, in the absence of coronary atheroma.11,12There is accumulating evidence of accelerated atherogenesis occurring in systemic inflammatory diseases such as RA and systemic lupus erythematosis,13,14raising the possibility that RA and atherosclerosis share common pathogenic mechanisms. Preliminary evidence suggests that inflammatory mediators such as C-reactive protein, interleukins, and tumor necrosis factor play a major role in this process.13,15,16Coronary angiography performed in our patient 10 weeks postoperatively did not show evidence of significant coronary atheroma, raising the possibility of coronary arteritis being a significant factor in the etiology of MI in this case.
In addition to inflammatory mechanisms, drug therapy may increase susceptibility to development of atherosclerosis in patients with RA. Corticosteroids have a recognized atherogenic effect.17Homocysteine, a novel factor recently associated with atherothrombosis, is increased in patients with RA.18Long-term use of methotrexate induces increased homocysteine concentrations, possibly further increasing the risk of atherosclerosis.19It has been suggested that “novel cardiovascular risk factors,” including increased homocysteine concentrations, and inflammatory markers, such as C-reactive protein, may be more reliable indicators of increased risk of cardiovascular morbidity in RA than traditional cardiac risk factors.1
In summary, we report an acute MI occurring in the early postoperative period, after uneventful anesthesia, in a patient with long-standing RA and no other traditional risk factors for cardiac disease. The high prevalence of coexisting CAD in patients with long-standing RA, coupled with the lack of consistent association with traditional cardiac risk factors, and the frequent occurrence of silent disease highlight the importance of maintaining a high index of suspicion for increased risk of perioperative myocardial ischemia in these patients. Anesthetic management of patients with long-standing RA should therefore include careful preoperative evaluation for CAD, appropriate intraoperative hemodynamic monitoring and risk-reducing strategies, and vigilant cardiac monitoring in the early postoperative period.
*Beaumont Hospital, Dublin, Ireland. firstname.lastname@example.org