Comparison of combination of dipyridamole and dobutamine during echocardiography with thallium scintigraphy to improve viability detection

The aim of this study was to investigate the relation between radioisotopic and echocardiographic markers of myocardial viability and their correlation with functional recovery after coronary revascularization. Myocardial viability can be detected by techniques exploring various aspects of cell physiology: thallium-201 scintigraphy and dobutamine and dipyridamole echocardiography focus on cell membrane integrity, β-1 and adrenoceptor, and A2-adenosine receptor-mediated inotropic response, respectively. Fifty-seven patients (mean age 60 ± 8 years) with previous myocardial infarction (>3 months), angiographically assessed coronary artery disease, and resting regional dysfunction underwent rest-redistribution 201-thallium scintigraphy and low-dose pharmacologic stress echo with dobutamine (up to 10 μg/kg/min), very low dose regimen of dipyridamole (0.28 mg/kg over 4 minutes), and combined dipyridamole-dobutamine. Criteria for viability in a 13-segment model for both techniques were percent peak activity in redistribution images >55% for thallium-201 and a decrease in wall motion score >1 grade (1 [normal] to 4 [dyskinetic]) for stress echo. Thirty patients underwent coronary revascularization (bypass surgery in 8, angioplasty in 22) and were followed up at 4 weeks from intervention with a resting echocardiogram. The rate of agreement between thallium-201 and stress echo was 63% for dipyridamole, 66% for dobutamine, and 74% for combined dipyridamole- dobutamine (p