Long term prognostic value of myocardial viability and ischaemia during dobutamine stress echocardiography in patients with ischaemic cardiomyopathy undergoing coronary revascularisation.

Abstract

To evaluate the relative merits of viability and ischaemia for prognosis after revascularisation. Low-high dose dobutamine stress echocardiography (DSE) was performed before revascularisation in 128 consecutive patients with ischaemic cardiomyopathy (mean (SD) left ventricular ejection fraction (LVEF) 31 (8)%). Viability (defined as contractile reserve (CR)) and ischaemia were assessed during low and high dose dobutamine infusion, respectively. Cardiac death was evaluated during a five year follow up. Clinical, angiographic, and echocardiographic data were analysed to identify predictors of events. Univariable predictors of cardiac death were the presence of multivessel disease (hazard ratio (HR) 0.21, p < 0.001), baseline LVEF (HR 0.90, p < 0.0001), wall motion score index (WMSI) at rest (HR 4.02, p = 0.0006), low dose DSE (HR 7.01, p < 0.0001), peak dose DSE (HR 4.62, p < 0.0001), the extent of scar (HR 1.39, p < 0.0001), and the presence of CR in > or = 25% of dysfunctional segments (HR 0.34, p = 0.02). The best multivariable model to predict cardiac death included the presence of multivessel disease, WMSI at low dose DSE, and the presence of CR in > or = 25% of the severely dysfunctional segments (HR 9.62, p < 0.0001). Inclusion of ischaemia in the model did not provide additional predictive value. The findings of the present study illustrate that in patients with ischaemic cardiomyopathy, the extent of viability (CR) is a strong predictor of long term prognosis after revascularisation. Ischaemia did not add significantly in predicting outcome.