[Do thrombocyte aggregation inhibitors modify silent episodes of unstable angina pectoris in combined anti-angina therapy?]

Pathological and clinical studies suggest that platelets play role in the pathogenesis of unstable angina. This study investigated the effect of aspirin on silent episodes of unstable angina. Patient exclusion criteria were acute infarction, left bundle branch block, and ST-depression greater than 0.1 mV in the ECG. 27 patients (pts; 20 m, 7 f; 42-72 yrs) in the CCU with unstable angina were randomized in two groups. Group A received a combination on nitrates, beta-blockers, and calcium entry blockers; in group B aspirin (500 mg/day) was added. 6 h after initiating therapy, Holter-ECG was implemented for 48 h. One pt of group A was excluded owing to infarction within these 48 h. 4 of 13 pts in group A and 5 of 13 in group B showed no ST-Segment abnormalities. 6 pts from each group displayed 2 to 5 ST-depressions greater than 0.1 mV from up to 10 min in 24 h; 3 in group A and 2 in group B had 1-5 lasting 11 to 25 min. In the second 24 h period, the number of ST-depressions decreased distinctly. Statistically, the results obtained did not differ significantly in the two groups. Furthermore, the duration of the silent ischemia did not correlate with the severity of coronary stenosis (angiography 3-8 days after admission). Thus, when combined with the aforementioned triple therapeutic regimen, aspirin does not appear to influence the silent episodes of unstable angina pectoris.