Preoperative revascularization: While it makes intuitive sense that preoperative revascularization of high-risk patients would decrease their risk of perioperative cardiac complications, evidence countering this idea is nearly definitive. In a study by McFalls, revascularization prior to major vascular surgery did not decrease the risk of perioperative MI or 30-day mortality; however, it delayed the surgical procedure, even in patients with high-risk noninvasive test results.5,6 It is generally accepted that if these high-risk patients can safely undergo major vascular surgery without revascularization, a lower-risk patient such as ours can do so at even lower risk.
In these trials, revascularization occurred in addition to medical management of coronary disease, including aspirin, statin, and—particularly in the study by Poldermans,6 where beta-blockers were started and titrated well before surgery—beta-blocker therapy.
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Patients with active cardiac symptoms or signs or uncharacterized anginal symptoms should have elective surgery delayed. However, delay is rarely an option for the hospitalist, who is typically asked to address a patient’s risk shortly before urgent or emergent surgery. These difficult situations require one to weigh the cardiac risk of surgery in a patient who is not optimized versus the risk of delaying surgery to address the more urgent cardiac situation.
Timing of perioperative percutaneous intervention: For patients with coronary artery disease (CAD) or coronary lesions, the interval between percutaneous revascularization (via stent or percutaneous transluminal coronary angioplasty [PTCA]) and surgery affects rates of postoperative cardiac events.7
The recommended interval between stent placement and noncardiac surgery for patients receiving bare-metal and drug-eluting stents is six weeks and one year, respectively.8 Surgery within two weeks of stent placement can carry mortality rates as high as 40%, and this risk appears to decrease out to one year.9,10 If a new stent is in place, any potential benefit appears to be offset by the increased risk of in-stent thrombosis with subsequent MI and possible death. PTCA may not be a safe alternative, although some recommend using PTCA if the patient has unstable cardiac symptoms and needs urgent/emergent surgery.11
Perioperative discontinuation of dual antiplatelet agents (e.g., clopidogrel and aspirin) is common and appears to increase thrombosis risk. This presents a challenge when patients with recent stent placement present for urgent surgery. Minimizing the interruption of dual antiplatelet therapy is the most important intervention a hospitalist can perform. Interruption is associated with increased risk of stent thrombosis, MI, and death. If clopidogrel must be discontinued in the perioperative period, continuation of aspirin is recommended and intravenous glycoprotein 2b/3a inhibitors can be considered.12
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Perioperative beta-blocker: Studies on the outcomes of perioperative beta blockade strongly suggested benefits initially. But a number of randomized trials in the past three years have not shown a positive effect.
In a landmark study published in 1996, Mangano showed that initiation of beta blockade just prior to surgery reduced perioperative MI and cardiac death in a mixed surgical population.13 Similar findings were seen with initiation of beta-blocker one month prior to vascular surgery.14 Additionally, higher doses of beta-blocker and lower heart rates in the perioperative period seem to be associated with decreased troponin release.15 Finally, perioperative beta blockade was associated with decreased mortality in high-risk patients (RCRI of three or greater), but higher mortality in lower-risk patients (e.g., RCRI of zero or one).16
More recent data reveal less benefit for perioperative beta blockade. Yang, et al., suggested that initiation of beta-blockers just prior to surgery did not decrease postoperative cardiac complications in vascular surgery patients.17 Similar results were found in a cohort of diabetic patients undergoing major surgery.18 A subsequent meta-analysis concluded that, in the aggregate, perioperative beta blockade was neither beneficial nor harmful.19
