Individual prediction of functional recovery after coronary revascularization in patients with ischemic cardiomyopathy: the scar-to-biphasic model.

Currently, the prediction of improvement of left ventricular (LV) ejection fraction (EF) after revascularization in patients with ischemic cardiomyopathy relies only on viable myocardium extent, whereas both the amount of viable and scar tissue may be important. A model was developed, based on the amount of viable and nonviable myocardium, to predict functional recovery. Viable and scarred myocardium was defined by dobutamine stress echocardiography (DSE) in 108 consecutive patients. LVEF before and 9 to 12 months after revascularization was assessed by radionuclide ventriculography; an improvement of > or =5% was considered significant. In the 1,089 dysfunctional segments (63%), DSE elicited biphasic response in 216 segments (20%), sustained improvement in 205 (19%), worsening in 43 (4%), and no change in 625 (57%). LVEF improved in 39 patients (36%). Only the numbers of biphasic and scar segments were predictors of improvement or no improvement of LVEF (odds ratio 1.5, 95% confidence interval 1.2 to 1.7, p <0.0001 for biphasic segments; odds ratio 0.8, 95% confidence interval 0.7 to 0.9, p <0.0005 for scarred segments). The sustained improvement and worsening pattern were not predictive of improvement or no improvement. A regression function, based on the number of scar and biphasic segments, showed that the likelihood of recovery was 85% in patients with extensive biphasic tissue and no scars and 11% in patients with extensive scars and no biphasic myocardium. Patients with a mixture of scar and biphasic tissue had an intermediate likelihood of improvement (50%). In patients with ischemic cardiomyopathy and a mixture of viable and nonviable tissue, both numbers of viable and nonviable segments should be considered to accurately predict functional recovery after revascularization.