Effect of improvement in left ventricular ejection fraction on long-term survival in revascularized patients with ischaemic left ventricular systolic dysfunction

Abstract

The importance of improvement in the ejection fraction to the prognosis of revascularized patients with ischaemic left ventricular (LV) dysfunction is uncertain. Eighty-seven patients with ischaemic LV dysfunction (mean ejection fraction 29 ± 8% by biplane Simpson's) had dobutamine echocardiography before revascularization (coronary bypass graft surgery-81, percutaneous intervention-6). Follow-up echocardiograms were performed a mean of 4.8 ± 6.2 months after revascularization. An 8% increase in the ejection fraction was considered significant (two times the inter-observer difference of 3.7%). Patients were followed for cardiac death. During a mean follow-up of 5.2 ± 3.9 years, there were 20 (23%) cardiac deaths. Class 3/4 heart failure, increasing low-dose wall motion score, increasing % non-viable myocardium, and digoxin use in follow-up were univariate predictors of death. Beta-blocker use, ejection fraction improvement, angina, aspirin use, and increasing fractional shortening were univariate predictors of survival. Ejection fraction improvement [P= 0.02, hazard ratio (HR) = 0.26], digoxin use in follow-up (P= 0.006, HR = 5.85), and low-dose wall motion score (P= 0.017, HR = 4.78) were independent predictors of outcome. In step-wise analysis, low-dose wall motion score added incremental prognostic value to ejection fraction improvement (P= 0.003), and digoxin use in follow-up (P= 0.003) added incremental value to a low-dose score and ejection fraction improvement. Ejection fraction improvement is an independent predictor of long-term outcome in revascularized patients but viability (low-dose wall motion score) and digoxin use in follow-up are also independent predictors and add incremental prognostic value to ejection fraction improvement.