Myocardial infarct expansion during indomethacin or ibuprofen therapy for symptomatic post infarction pericarditis. Influence of other pharmacologic agents during early remodelling.

Evidence of acute infarct expansion and the frequency of the acute infarct expansion syndrome (acute infarct dilatation and thinning associated with hypotension and left ventricular failure but no evidence of new necrosis) occurring at two days or more after a first acute Q-wave myocardial infarction were studied using serial two-dimensional echocardiography in 221 consecutive patients (100 anterior, 121 inferior). Patients with symptomatic pericarditis were treated with indomethacin (group 1, n = 73) or ibuprofen (group 2, n = 49) and those without symptomatic pericarditis received neither drug (group 3, n = 99). The overall frequency of the acute infarct expansion syndrome was 13% and 69% of these were among the pericarditis groups. The syndrome was significantly more frequent in group 1 (22%) than group 2 (8%) (P less than 0.05) or group 3 (9%) (P less than 0.025). Serial echocardiograms revealed more expansion with greater percentage increase in the infarct containing segment length in group 1 than group 2 or group 3 (18% versus 9% versus 9%, P less than 0.005). However, the decreases in infarct segment thickness were similar in groups 1 (24%) and 2 (25%) but greater (P less than 0.001) than in group 3 (7%). Despite similar infarct size and infarct thinning in groups 1 and 2, the degree of infarct expansion was greater and the infarct expansion syndrome more frequent in group 1. However, when allowance was made for the potential protective effect of prior use of intravenous nitroglycerin and concomitant use of nifedipine, indomethacin and ibuprofen had similar effects on expansion. Thus, indomethacin or ibuprofen should be used with caution after Q-wave infarction so as to avoid further expansion. The fact that short term use of other drugs might modify infarct remodelling should be considered in studies attempting to assess efficacy of one particular drug.(ABSTRACT TRUNCATED AT 400 WORDS)