Does exercise-induced myocardial ischaemia cause enhanced platelet activation and fibrin formation in patients with stable angina and severe coronary artery disease?

In this study, betathromboglobulin (BTG) and fibrinopeptide A (FPA) in peripheral venous blood were measured in 20 patients with stable angina pectoris before and immediately after exercise-induced myocardial ischaemia; in 5 of the 20 patients stable angina was associated with typical peripheral artery disease. A total of 10 patients with angiographically documented peripheral artery disease without angina and 10 normal volunteers were taken as control groups. BTG and FPA in the 15 patients with stable angina before exercise were 41 +/- 14 ng ml-1 and 2.3 +/- 0.9 ng ml-1 and were not statistically different from the values in normal controls; after exercise-induced myocardial ischaemia no significant increase occurred in these patients. Conversely, in the 5 patients with stable angina associated with peripheral artery disease BTG and FPA before exercise were 61 +/- 10 ng ml-1 and 3.5 +/- 0.8 ng ml-1 and increased to 114 +/- 14 ng ml-1 (P less than 0.001) and 4.1 +/- 0.5 ng ml-1 (P less than 0.01): These results were similar to those found in the 10 patients with isolated peripheral artery disease. We conclude that BTG and FPA in peripheral venous blood in patients with stable angina are not elevated either at rest or after exercise-induced myocardial ischaemia. Elevated values of BTG and FPA in patients with stable angina may reflect a major interaction between blood and atherosclerotic vessel wall, suggesting the presence of associated atherosclerotic lesions in peripheral artery disease.