Effect of a standardized meal on the threshold of exercise-induced myocardial ischemia in patients with stable angina

Abstract

Objectives. This study was undertaken to determine the effect of a standardized meal on the ischemie threshold and exercise capacity in a series of 20 patients with stable angina, exerciseinduced ischemia and reversible exercise-induced perfusion defects.Background. It is generally accepted that exercise tolerance in patients with angina is reduced after a meal. However, studies that have addressed this phenomenon have yielded results that are contradictory and inconclusive.Methods. Two exercise tests using the Brace protocol with technetium-99m (99mTc)-sestamibi were performed on consecutive days in a randomized order. One test was performed in the fasting state and the other 30 min after a 1,000-calorle meal.Results. In the postprandial state, exercise time to ischemia was reduced by 20% from 248 ± 93 s to 197 ±87 s (p = 0.0007), time to angina by 15% from 340 ± 82 s to 287 ± 94 s (p = 0.002) and exercise tolerance by 9% from 376 ± 65 s to 344 ± 86 s (p = 0.002). Rate-pressure products at these exercise test end points were not significantly different in the fasting and postprandial tests, and the quantitative 99mTc-sestamibi ischemia score was unchanged.Conclusions. In patients with stable angina, a 1,000-calorie meal significantly reduced tine to ischemia, time to angina and exercise tolerance because of a more rapid increase in myocardial oxygen demand with exercise. The extent and severity of exerciseinduced ischemia were unchanged.