Background: Beta-blockers are potent anti-ischemic medications, able to improve prognosis in patients with coronary artery disease (CAD). However, it is not known whether beta-blockers have the same beneficial prognostic effect when residual ischemia persists on treatment.
Methods and results: The prognostic impact of exercise single photon emission computed tomography (SPECT) ischemia was analyzed in 442 patients with chronic CAD, who were treated with beta-blockers and who were referred to exercise thallium 201 SPECT, while they were receiving their daily-life medications. Ischemic and viable myocardium was documented on Tl-201 SPECT in 190 patients (43%), of whom only 23% had angina and only 26% had positive exercise testing results. During a follow-up of 3.8 +/- 1.7 years, 36 patients died and survival curves were progressively divergent between patients with and those without ischemic and viable myocardium: at 5 years, the respective survival rates were 81% +/- 4% and 94% +/- 2% (P =.004). By multivariate analysis, the best independent predictors of death were large extent of necrosis (>25% of left ventricle on Tl-201 SPECT, P <.001) and ischemic and viable myocardium (P =.001).
Conclusions: In the CAD patients treated on a long-term basis with beta-blockers, survival is strongly influenced by persistent exercise SPECT ischemia on treatment. Therefore exercise SPECT on treatment could be a useful tool for selecting those who might benefit from additional anti-ischemic therapeutic interventions.