Cardiac events in patients with negative maximal versus negative submaximal dobutamine echocardlograms undergoing noncardiac surgery - Importance of resting wall motion abnormalities

OBJECTIVES This study sought to evaluate the negative predictive value (NPV) of preoperative dobutamine stress echocardiography (DSE) in patients who fail to achieve target heart rate (HR) and assess the influence of resting wall motion abnormalities (WMAs) without demonstrable ischemia on perioperative events. BACKGROUND The prognostic value of a negative-submaximal DSE study before noncardiac surgery is unknown. METHODS Consecutive patients (n = 429) who underwent surgery over a three-year period, preceded by DSE, were included. We compared perioperative event rates among those without inducible ischemia according to whether or not 85% age-adjusted maximum HR was achieved, and whether WMAs were present at rest. RESULTS Of 397 negative DSEs, peak HR was <85% maximum predicted in 62 (16%). Most were receiving beta-blockers (77%). The average dobutamine and atropine doses were 48 mug/kg/min and 1.2 mg, respectively. Average HR was 115 beats/min (74% maximum predicted). Perioperative myocardial infarctions occurred more frequently in patients with positive tests (3 of 32 [9.4%] vs. 7 of 397 [1.8%]; p = 0.03), but with similar frequency among the negative-maximal and negative-submaximal groups (6 of 335, 1.8% vs. 1 of 62, 1.6%, respectively). Accordingly, the NPV was 98% in both subgroups. Events occurred exclusively in patients with WMAs at rest: 7 of 100 (7%) versus 0 of 297 (0%) (p < 0.0001). CONCLUSIONS In patients undergoing preoperative DSE, failure to achieve target HR is not uncommon despite an aggressive DSE regimen. A negative DSE without resting WMAs has excellent NPV regardless of the HR achieved. Patients with resting WMAs appear to be at increased risk for perioperative events even without provokable ischemia. (C) 2004 by the American College of Cardiology Foundation.