Level 2: Mid-level evidence

An echocardiogram is often performed prior to non­- cardiac surgery to identify patients at risk of cardiac complications even though the American College of Cardiology recommends against routine perioperative evaluation of left-ventricular function in such patients (Circulation. 2007;116:e418-e499).

A recent retrospective cohort study suggests that preoperative echocardiography may provide little benefit (BMJ. 2011;342: d3695). From a co­­hort of 264,000 patients aged 40 years and older having elective intermediate or high-risk noncardiac surgery, 35,498 patients who had a preoperative resting echocardiogram were matched to an equal number with no echocardiogram. Matching was based on multiple factors including demographics, comorbidities, type of surgery planned and hospital characteristics.

The echocardiogram group had significantly increased mortality at 30 days (2% vs. 1.7%, P<0.05, NNH=423) and at one year (7.4% vs. 6.9%, P<0.05, NNH=222). Echocardiography was also associated with increased hospital stay (mean difference 0.31 days). There were no significant differences in surgical site infections, a marker for perioperative risk that is unaffected by echocardiogram (13.2% vs. 12.9%). A subgroup analysis showed no significant difference in one-year mortality in patients who had a preoperative stress test.