Evaluation and management during non-cardiac surgery
In general, preoperative myocardial revascularization (e.g., PCI, CABG) is
indicated in patients for whom it would be indicated even if there were no elective surgery, e.g.,
selected patients with very symptomatic CAD despite medical therapy, or those with strongly
positive ECG exercise or pharmacological radionuclide or echo stress tests. Otherwise, no data
exists to support doing prophylactic PCI or CABG before noncardiac surgery just to reduce the
incidence of postoperative cardiac complication. Coronary stents are now being used in more than
80% of percutaneous coronary interventions. It is prudent to delay elective surgery for at least
four weeks after intracoronary stenting, to allow complete endothelialization and to avoid the
possibility of acute stent thrombosis that may result from discontinuation of anticoagulant therapy
(i.e., aspirin, clopidogrel) prior to planned surgery.
Clinical experience indicates that patients with symptomatic valvular AS severe
enough to warrant surgical treatment should have valve surgery (or catheter balloon valvuloplastry
as a temporizing step) before elective ( or urgent) noncardiac surgery. Patients with severe MR may
benefit from afterload reduction and diuretic therapy to produce maximal hemodynamic stabilization
before high risk surgery. The severity of valvular lesions should be determined prior to surgical
to allow for appropriate fluid management and consideration of invasive intraoperative
monitoring.All patients with valvular heart disrase should receive appropriate antibiotic
prophylaxis for endocarditis.
Myocardial ischemia and adverse postoperative cardiac events may occur with a
postoperative hypercoagulable state, surge in catecholamine levels, hemodynamic changes, hypoxemia,
and fluid shifts. For high risk patients, administering beta blockers preoperatively and
maintaining treatment uninterrupted as long as possible(especially in patients with CAD) may be
helpful in reducing these complications (particularly ischemia and postoperative MI and
arrhythmias). Most cardiac medications should be continued up to surgery, especially antianginal
and antihypertensive medications. The practitioner should excercise particular caution in
withdrawing beta blockers and clonidine because of potential rebound ischemia and/or hypertension.
Because of other pain or sedation, perioperative MIs may be "silent" or present with other signs
(e.g., CHF or arrhythmias).