We appreciate the interest and valuable comments of Drs. Quintin and Ghignone in our Editorial View published in the January issue of Anesthesiology.1Along with β blockers, α2agonists may offer significant protection against cardiac morbidity and mortality in patients undergoing major noncardiac surgery.2–5α2Agonists have also been proposed as an alternative cardioprotective treatment strategy in high-risk surgical patients who have relative or absolute contraindication to β-blocker use.6To support their view, Drs. Quintin and Ghignone refer to large-scale clinical trials and several meta-analyses performed in recent years. However, the only large-scale study available to date is that of Oliver et al. ,5which showed no overall effect of mivazerol (an intravenous α2agonist) on the prespecified combined endpoint of myocardial infarction and cardiac death in the whole study population of 2,854 patients. Only a post hoc analysis showed that in a subgroup of 904 patients with known coronary artery disease who underwent major vascular surgery, mivazerol was associated with a significantly lower incidence of the combined endpoint. The meta-analyses cited also show similar findings that perioperative benefits may depend largely on the patients at risk and the surgical procedure involved, with the largest benefit observed in patients undergoing major vascular surgery.2–4These findings and Drs. Quintin and Ghignone’s7own experience prompted them to surmise that clinicians could consider α2agonists as first-line drugs. However, the previous meta-analysis that concluded that clonidine reduced perioperative ischemia4was underpowered (358 noncardiac surgical patients in two studies), and effects were only reported on ischemia.3Furthermore, the results of the two more recent meta-analyses2,3are mainly driven by the results of the large-scale mivazerol trial.
In summary, we agree with the statement of Drs. Quintin and Ghignone that future studies directly comparing α2agonists and β blockers are needed. Until then, high-risk patients undergoing major noncardiac surgery should be given β blockers that not only reduce perioperative cardiac morbidity but also improve long-term outcome in patients with coronary artery disease, congestive heart failure, and hypertension.8–11In case of contraindication to β blockers, an α2agonist should be considered as a possible alternative to reduce perioperative cardiac complications.12
* Erasmus Medical Center, Rotterdam, The Netherlands. firstname.lastname@example.org