New guide targets heart patients undergoing noncardiac surgery

January 28, 2008

New guidelines have been issued related to the use of perioperative drugs for cardiac patients.

Although it was previously unclear what to do about cholesterol-lowering statins in patients with heart disease who were about to undergo noncardiac surgery, new clinical trial evidence shows a protective effect of perioperative statin use on cardiac complications during surgery. Therefore, statins should not be discontinued before surgery, according to the new guide.

"The cardiovascular benefits of statins are well known and decrease both cardiovascular morbidity and mortality in patients who have heart disease and those with risk factors for heart disease," said Michael A, Militello, Pharm.D., a cardiology clinical specialist at the Cleveland Clinic. Discontinuation prior to surgery could lead to increased incidence of cardiovascular events, he said. Also, it is now reasonable to use statins in patients undergoing vascular surgery and in patients with at least one cardiovascular risk factor undergoing an intermediate-risk procedure such as orthopedic, prostate, or head and neck surgery, he explained.

The antiplatelet therapy duration varies for patients who have undergone percutaneous coronary intervention (PCI) and who need elective noncardiac surgery, according to Militello, and depends on the modality of PCI performed. Specifically, for patients who have had PCI with placement of a bare metal stent (BMS), dual anitplatelet therapy should be continued for four to six weeks after PCI and noncardiac surgery delayed until that time. "The thienopyridine should be discontinued one week prior to any noncardiac surgery to allow for adequate washout of antiplatelet effect," he explained. However, "if a noncardiac surgery needs to be performed prior to four weeks after BMS placement, then the dual therapy should be continued since the risk of stent thrombosis is significant," he added.

Since late stent thrombosis risk is significant for drug-eluting stents (DES), and premature discontinuation of therapy significantly increases the risk of cardiovascular events including death and myocardial infarction, the minimum duration of dual antiplatelet therapy is 12 months after DES implantation. "Any elective surgery or procedure with a significant risk of bleeding should be delayed," Militello said. However, patients with a DES who must undergo urgent noncardiac surgery that requires discontinuing thienopyridine therapy should continue aspirin if possible, and the antiplatelet agent restarted as soon as possible.

Beta-blockers should be continued in patients undergoing surgery who are receiving them to treat angina, symptomatic arrythmias, and hypertension, according to ACC and AHA. "The new guidelines consider vascular surgery as the highest risk for post-operative cardiovascular events and recommend that patients with coronary artery disease (CAD) or those at high risk of CAD should initiate beta-blocker therapy," Militello explained. He went on to say that institution of beta-blockers is also reasonable in patients undergoing intermediate-risk surgery if they have CAD or high cardiac risk (more than one risk factor). Finally, the use of beta-blockers in patients undergoing low- or intermediate-risk procedures in patients without cardiac risk factors is not necessary, he explained.

The new guide does not include any Class 1 recommendations for the use of alpha-2 agonists, but says they may be considered in the treatment of perioperative hypertension in patients with known CAD or in those who have at least one clinical risk factor and are undergoing surgery.

The update also addresses the use of volatile anesthetic agents as well as prophylactic intraoperative nitroglycerin. The report is available at http://www.circ.ahajournals.org/cgi/content/full/116/17/e418/.