Background: We sought to investigate whether the paucity of anginal symptoms in patients with ischemic cardiomyopathy reflects a reduction in the severity of stress-induced myocardial ischemia.
Methods and results: We selected 38 patients with coronary artery disease and severe left ventricular dysfunction (ejection fraction [EF] <or=25%) (group 1), who underwent stress gated single photon emission computed tomography. In parallel, we selected 2 groups of 38 patients with coronary artery disease and EF between 26% and 45% (group 2) or EF greater than 45% (group 3), matched to group 1 patients. Effort angina was less frequent in group 1 (29%) than in group 2 (50%) and group 3 (82%) (P = .023). Stress-induced perfusion abnormalities, identified by the summed difference score (SDS), were less extensive in group 1 (mean SDS, 3 +/- 3) than in group 2 (mean SDS, 6 +/- 5) and group 3 (mean SDS, 8 +/- 4) (P = .019), whereas perfusion abnormalities at rest (summed rest score [SRS]) were more extensive in group 1 (mean SRS, 12 +/- 4) than in group 2 (mean SRS, 6 +/- 3) and group 3 (mean SRS, 3 +/- 2) (P = .015).
Conclusion: The paucity of anginal symptoms in ischemic cardiomyopathy reflects a limited extent of stress-induced myocardial ischemia and a higher extent of necrosis.