Postprandial silent ischaemia following a fatty meal in patients with recently diagnosed coronary artery disease

Silent myocardial ischaemia (SI) is recognised as an important prognostic f actor in patients with coronary artery disease (CAD). Postprandial angina i s related to severity of CAD. The effect of postprandial metabolic changes in the pathogenesis of SI is unclear. We studied the postprandial changes i n glucose, insulin and triglyceride, and non-esterified fatty acids (NEFA) in relation to postprandial SI and exercise capacity, in patients with CAD. Forty elderly volunteers (63 +/- 1 years) mean age +/- s.e.m,, with a hist ory of angina were selected on the basis of a Rose questionnaire and a posi tive exercise stress test (modified Bruce protocol). The test meal containe d 45% fat, The meal was consumed at 9.00 am and hourly blood samples were t aken for glucose, insulin, triglyceride and NEFA. Continuous Holter monitor ing for SI was conducted using a Spacelabs 2000 monitor. Twenty-five percen t of the subjects had episodes of silent ischaemia. Postprandial glucose, i nsulin, triglyceride, and NEFA were not significantly different in the pati ents with SI (group 1, n = 10) compared with those without SI (group 2, n = 30). The mean exercise time was 6.1 +/- 0.8 min in group 1 compared with 6 .8 +/- 0.5 minutes in group 2 (P = 0.48). The time to onset of ST depressio n during exercise test was also not significantly different in the two grou ps. The occurrence of postprandial SI cannot be related to changes in plasm a levels of glucose, triglyceride, insulin, and NEFA. The explanation is no t apparent from this study but may relate to a haemodynamic changes such as mesenteric steal.