Stress Echocardiography in Patients With Moderate or Severe Myocardial Ischemia: Insights From the ISCHEMIA Trial
Michael H Picard1, Kyle Saysana1, Derek D Cyr2
1Massachusetts General Hospital, Boston, Massachusetts; Harvard Medical School, Cambridge, Massachusetts.
Insights
Stress echocardiography effectively identifies significant coronary artery disease and predicts adverse outcomes in patients with chronic coronary disease. Wall motion score index from this imaging modality offers valuable prognostic information.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Clinical Outcomes
Background:
- The International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trial investigated treatment strategies for chronic coronary disease.
- Stress echocardiography's role in relation to coronary artery anatomy and patient outcomes requires further examination.
Purpose of the Study:
- To assess the relationship between stress echocardiography findings, coronary artery anatomy, and clinical outcomes in ISCHEMIA trial participants.
- To determine the prognostic value of stress echocardiography parameters, including wall motion score index and transient ischemic dilation.
Main Methods:
- Utilized data from 1,079 patients undergoing stress echocardiography within the ISCHEMIA trial.
- Coronary computed tomographic angiogram (CCTA) was used to evaluate coronary artery anatomy and quantify lesions.
- Ischemia severity was defined by stress-induced wall motion abnormalities and transient ischemic dilation.
Main Results:
- Coronary computed tomographic angiogram (CCTA) identified significant coronary lesions (≥70%) in 84% of evaluable patients.
- Transient ischemic dilation was observed in 28.5% of cases and correlated significantly with ischemia severity.
- An increased peak wall motion score index was associated with a 12% higher risk of cardiovascular death or myocardial infarction (aHR=1.12).
Conclusions:
- Stress echocardiography is valuable in identifying patients with significant coronary artery disease and moderate to severe myocardial ischemia.
- The wall motion score index derived from stress echocardiography provides significant prognostic value for cardiovascular events.
- These findings support the utility of stress echocardiography in managing patients with chronic coronary disease receiving contemporary therapies.
Background:
This study examined stress echocardiography 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, stress echocardiography 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 (mild < 3, moderate = 3, and severe > 3). Transient ischemic dilation was defined as a 10% increase in stress left ventricular end-systolic volume. Primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest.
Results:
On CCTA, 607/715 (84%) with CCTA evaluable for ≥70% lesion had 1 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 left ventricular ejection fraction 10 percentage points. Transient ischemic dilation, present in 28.5% of cases, was significantly associated with severity of ischemia. For every 0.10 increase in peak wall motion score index, there was a 12% increased risk of cardiovascular death or myocardial infarction (adjusted hazard ratio = 1.12; 95% CI, 1.04, 1.21; P = .003).
Conclusion:
In patients with chronic coronary disease and moderate or severe myocardial ischemia receiving contemporary therapies, stress echocardiography identified subjects with significant coronary artery disease and wall motion score index provided prognostic value.
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