Tuhin Haque, MBBS; Takami Furukawa, MD; Masayuki Takahashi, MD; Keiko Maeda, MD; Masahiko Kinoshita, MD

Abstract
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 can predict the long-term (>2 years) outcome after PTCA is still unclear. Thus, 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 myocardial viability were followed for 4.0±0.8 years. Regional LV function and LV ejection fraction (LVEF) were evaluated by 2-dimensional echocardiography in patients who remained event-free (cardiac death or myocardial infarction or unstable angina pectoris) after PTCA. At late follow-up (>2 years after PTCA), 29 patients showed regional LV function improvement, 15 showed no improvement, 3 showed worsen-ing and 3 patients had cardiac events (1 nonfatal myocardial infarction and 2 unstable angina pectoris). LVEF improved (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 patients 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 improvement had viable myocardium and all 6 of those with poor outcomes (3 with cardiac events and 3 with worsening) had viable myocardium (chi2 =28.9, p<0.001). Patients with viable myocardium and a poor outcome had a lower mean 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 patients with viable myocardium and without a poor outcome. It is concluded that viable myocardium detected by DE may predict long-term improvement in regional and global LV function after PTCA. However, patients with viable myocardium and persistent low LVEF are at risk for cardiac events or worsening of LV function.
(Jpn Circ J 2000; 64: 183- 190)

Key Words: Dobutamine echocardiography; Long-term outcome; Percutaneous transluminal coronary angioplasty (PTCA); Viable myocardium

Mailing address: Professor Masahiko Kinoshita, The First Department of Internal Medicine, Shiga University of Medical Science, Seta, Tsukinowa-cho, Otsu, Shiga 520-2192, Japan