Correlation of coronary arteriography after acute myocardial infarction with predischarge limited exercise test response.

This study of post-acute myocardial infarction (AMI) patients compared the extent and distribution of coronary narrowings and left ventricular dysfunction in 45 patients who had greater than or equal to 1 mm ST-segment depression on a predischarge low-level exercise test (positive-result group) with those found in 78 patients who had less than 1 mm ST depression (negative-result group). Cardiac catheterization was done 50 +/- 20 days (mean + standard deviation) after AMI. Patients with positive responses more often had multivessel coronary artery disease (80 vs 47%, p = 0.001) and a greater than or equal to 75% narrowing in the left anterior descending (LAD) (87 vs 62%, p = 0.003) and left circumflex (71 vs 37%, p = 0.001) arteries, as well as in the proximal LAD segment before the first septal branch (58 vs 29%, p = 0.002). Among patients with positive responses 93% had normal or hypokinetic wall motion in the vascular territory of a severely diseased coronary artery (viable but potentially ischemic myocardium) while 63% of the negative-result group had these findings (p = 0.001). No difference in ejection fraction could be identified between the 2 groups (54 +/- 15% vs 54 +/- 16%). Prior studies of AMI patients have shown that ST-segment depression on a predischarge low-level exercise test will identify patients at higher risk of subsequent cardiac death. Our observations have identified differences in cardiac angiographic findings between patients with positive and negative responses to this test that may explain this difference in outcome.