Clinical characteristics and outcomes of patients with severe left ventricular dysfunction undergoing cardiac MRI
Demetrios Doukas1, Katerina Porcaro1, Jessica Marot2
1Division of Cardiology, Loyola University Chicago Stritch School of Medicine, and Loyola University Health System, Maywood, IL, USA.
Insights
Cardiac magnetic resonance imaging (CMR) viability testing helps guide revascularization in ischemic cardiomyopathy patients. Patients with >50% viability benefit from revascularization, reducing adverse events.
Area of Science:
- Cardiology
- Medical Imaging
Background:
- Coronary artery bypass grafting improves survival in ischemic cardiomyopathy but carries high risks.
- The utility of viability testing to guide revascularization in this population remains unclear.
- Cardiac magnetic resonance imaging (CMR) is a reference standard for infarct imaging but understudied in severe left ventricular dysfunction.
Purpose of the Study:
- To evaluate the role of CMR viability assessment in guiding revascularization decisions for patients with severe ischemic cardiomyopathy.
- To determine if CMR-guided revascularization impacts clinical outcomes compared to medical therapy alone.
Main Methods:
- A multicenter retrospective analysis of 154 patients with ejection fraction <35% assessed by CMR.
- Myocardial viability was quantified using the AHA 16-segment model based on scar transmurality.
- Patients were stratified based on viability percentage (>50% vs. <50%) and revascularization status.
Main Results:
- 43% of patients experienced adverse events over a median 3-year follow-up.
- Revascularization was associated with a reduced risk of composite adverse events (death, MI, HF hospitalization, stroke, VT) compared to medical therapy alone (HR 0.53, p=0.01).
- Patients with >50% viability undergoing revascularization had a 47% reduction in composite events (HR 0.53, p=0.02), while those with <50% viability had increased adverse events (p=0.01).
Conclusions:
- CMR viability assessment is a valuable tool for shared decision-making in revascularization for severe ischemic cardiomyopathy.
- Identifying patients with significant myocardial viability (>50%) can guide successful revascularization strategies.
- Revascularization in selected patients with severe LV dysfunction and viable myocardium improves outcomes.
Abstract:
Coronary artery bypass grafting improves survival in patients with ischemic cardiomyopathy, however, these patients are at high risk for morbidity and mortality. The role of viability testing to guide revascularization in these patients is unclear. Cardiac magnetic resonance imaging (CMR) has not been studied adequately in this population despite being considered a reference standard for infarct imaging. We performed a multicenter retrospective analysis of patients (n = 154) with severe left ventricular systolic dysfunction [ejection fraction (EF) < 35%] on CMR who underwent CMR viability assessment prior to consideration for revascularization. Using the AHA16-segment model, percent total myocardial viability was determined depending on the degree of transmural scar thickness. Patients with or without revascularization had similar clinical characteristics and were prescribed similar medical therapy. Overall, 43% of patients (n = 66) experienced an adverse event during the median 3 years follow up. For the composite outcome (death, myocardial infarction, heart failure hospitalization, stroke, ventricular tachycardia) patients receiving revascularization were less likely to experience an adverse event compared to those without revascularization (HR 0.53, 95% CI 0.33-0.86, p = 0.01). Patients with > 50% viability on CMR had a 47% reduction in composite events when undergoing revascularization opposed to medical therapy alone (HR 0.53, p = 0.02) whereas patients with a viability < 50% were 2.7 times more likely to experience an adverse event (p = 0.01). CMR viability assessment may be an important tool in the shared decision-making process when considering revascularization options in patients with severe ischemic cardiomyopathy.
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