Stress Echocardiography in Patients with Moderate or Severe Myocardial Ischemia: Insights from the ISCHEMIA Trial.

Abstract

Background: This study examined stress echocardiography (SE) in relation to coronary artery anatomy, and outcome in subjects randomized in the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) Trial.

Methods: Of 5,179 patients randomized to initial invasive or conservative strategy, SE was performed in 1,079. Coronary computed tomographic angiogram (CCTA) excluded left main disease and quantified coronary lesions. Degree of ischemia was defined by number of segments with stress-induced wall motion abnormalities (WMA) (mild < 3, moderate = 3 and severe > 3). Transient ischemic dilation (TID) was defined as a 10% increase in stress left ventricular (LV) end systolic volume. Primary end point was a composite of cardiovascular death (CVD), nonfatal myocardial infarction (MI), or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest.

Results: On CCTA, 607/715 (84%) with CCTA evaluable for ≥70% lesion had one such lesion. Features associated with coronary lesions ≥ 70% were number of ischemic/infarcted segments, 3 or more ischemic segments in the anterior territory and inability to augment LV ejection fraction 10 percentage points . TID, present in 28.5%, was significantly associated with severity of ischemia. For every 0.10 increase in peak wall motion score index (WMSI), there was 12% increased risk of CVD or MI (adjusted HR=1.12 (95% CI: 1.04, 1.21), p=0.003.

Conclusion: In patients with chronic coronary disease and moderate or severe myocardial ischemia receiving contemporary therapies, stress echocardiography identified subjects with significant CAD and WMSI provided prognostic value.