Myocardial viability detected by dobutamine echocardiography in patients with chronic coronary artery disease, and long-term outcome after coronary angioplasty

Viable but dysfunctional myocardium detected by dobutamine echocardiography (DE) predicts early improvement in regional left ventricular (LV) function after percutaneous transluminal coronary angioplasty (PTCA). Whether DE ca n predict the long-term (>2 years) outcome after PTCA is still unclear. Thu s, 50 patients (age 60.4+/-9.5 years) with chronic coronary artery disease and regional LV dysfunction who underwent DE 1 week before PTCA to assess m yocardial viability were followed for 4.0+/-0.8 years. Regional LV function and LV ejection fraction (LVEF) were evaluated by 2-dimensional echocardio graphy in patients who remained event-free (cardiac death or myocardial inf arction or unstable angina pectoris) after PTCA. At late follow-up (>2 year s after PTCA), 29 patients showed regional LV function improvement, 15 show ed no improvement, 3 showed worsening and 3 patients had cardiac events (1 nonfatal myocardial infarction and 2 unstable angina pectoris). LVEF improv ed (0.53+/-0.09 to 0.60+/-0.09, p<0.001) in patients with improved regional LV function, but deteriorated (0.38+/-0.03 to 0.30+/-0.03) in the 3 patien ts with worsened regional LV function. Of the 29 patients with improvement, 27 (93%) had viable myocardium, whereas only 3 (20%) of the 15 with no imp rovement had viable myocardium and all 6 of those with poor outcomes (3 wit h cardiac events and 3 with worsening) had viable myocardium (chi(2)=28.9, p<0.001). Patients with viable myocardium and a poor outcome had a lower me an LVEF before PTCA, and at 1 week and 3 months after PTCA (p=0.004, <0.001 , and =0.001, respectively), and a higher restenosis rate (p=0.007) than pa tients with viable myocardium and without a poor outcome. It is concluded t hat viable myocardium detected by DE may predict long-term improvement in r egional and global LV function after PTCA. However, patients with viable my ocardium and persistent low LVEF are at risk for cardiac events or worsenin g of LV function.