SURVIVAL AFTER MYOCARDIAL-INFARCTION IN RATS - CAPTOPRIL VERSUS LOSARTAN

Objectives, This study sought to compare the effects of angiotensin co nverting enzyme inhibition versus angiotensin II receptor blockade on survival in rats with myocardial infarction, Background. The effects o f specific nonpeptide angiotensin receptor blocking agents on survival after myocardial infarction are unknown, Methods. Rats with a moderat e to large myocardial infarction were treated with captopril (2 g/lite r drinking water, n = 87) or losartan (2 g/liter drinking water, n = 9 6), Therapy was initiated immediately after coronary artery ligation a nd continued for 1 year, Results. Uncensored median survival in captop ril-treated rats that survived at least 48 h was 201.5 days versus 236 .0 days for losartan-treated rats (p = 0.066). Median survival censore d for rats with lung infections was 201.5 days in captopril-treated ra ts versus 243.0 days for losartan-treated rats (p = 0.028), Conscious hemodynamic measurements and remodeling data obtained at 1 year in the surviving rats (n = 5 for captopril; n = 9 for losartan) revealed no differences in heart weight, left ventricular pressure, dP/dt, cardiac index, time constant of relaxation or any variable of left ventricula r remodeling, The only differences (mean +/- SD) were an increase in h eart rate (293 +/- 19 vs, 266 +/- 15 beats/min, p < 0.05) and a decrea se in peak developed pressure (153 +/- 21 vs, 180 +/- 16 mm Hg, p < 0. 05) in the losartan-treated rats, Conclusions. We conclude that in thi s experimental model of heart failure, there was no difference between survival after angiotensin II receptor blockade with losartan and wit h angiotensin converting enzyme inhibition with captopril.