[Effect of myocardial viability and coronary revascularization on clinical outcome and prognosis: a follow-up study of 161 patients with coronary heart disease].

One hundred and sixty-one consecutive patients (144 male, 57 +/- 9 years) with stable coronary artery disease underwent nuclear imaging for assessment of myocardial viability using Tc-99m sestamibi single-photon emission computed tomography (SPECT) and F-18 fluoro-deoxy-glucose (FDG) positron emission tomography (PET). 88% had a history of chronic myocardial infarction and all had angiographically proven regional wall motion (RWM) abnormalities in the distribution territory of a stenosed or occluded coronary artery. Patients were followed for 29 +/- 6 (22-44) months with 84/161 patients (52%) receiving elective revascularization by either bypass surgery or angioplasty. 61/84 patients underwent follow-up angiography after 5 +/- 2 months for quantitative assessment of RWM changes using serial analysis with the centerline method in 45 pts with technically suitable paired angiograms. Myocardial regions were classified according to semiquantitative analysis of regional sestamibi and FDG uptake as either normal, regions with evidence for maintained viability but no mismatch ("mild match"), regions with a perfusion/metabolism "mismatch," or scar. RWM improved in "mismatch" regions from -2.2 +/- 1.0 SD to -1.0 +/- 1.4 SD (p < 0.01) compared to the mean of a normal reference population. In contrast, in regions with a "mild match" or those classified as scar, RWM analysis revealed no functional changes at follow-up. For the assessment of clinical outcome, patients were divided into three groups depending on the result of viability imaging. Those with predominantly scar tissue in the target region for viability assessment (group A, n = 90), those with a "mild match" (B, n = 26), and group C (n = 45) consisting of patients with a "mismatch" pattern. Subsequent treatment was not blinded to nuclear imaging results and revascularization was performed in 30% of group A (group A2), 81% of group B, and 80% of group C, while the other patients were treated medically only. Cardiac events during follow-up were defined as cardiac death, myocardial infarction, unstable angina with subsequent revascularization, cardiac transplantation, and survived resuscitation without evidence for myocardial infarction. Group C demonstrated a significant reduction of cardiac events from 22% to 0% following revascularization, whereas in group A coronary revascularization did not influence the frequency of events. Subjective assessment of angina pectoris and heart failure symptoms revealed more patients with improvement following revascularization as compared to those treated medically. Thus, combined nuclear imaging using sestamibi SPECT and FDG PET with quantitative tracer uptake analysis allows detection of absent or preserved myocardial viability in regions with reduced perfusion and function with prognostic implication for regional myocardial functional outcome as well as for identification of patients who benefit most from coronary revascularization.