To the Editor: There are a number of factors that may contribute to the discrepancy in results between the study of Durrer et al.1 and that of Cohn et al.2 (May 13 issue). Durrer et al. used nitroprusside earlier (5 vs. 12 hours) and in presumably higher doses (maximum, 500 vs. 200 μg per minute). Their therapeutic goal (systolic blood pressure of 100 mm Hg) was uniform and well defined; the goal of Cohn et al. was variable (either a 60 per cent reduction in left ventricular filling pressure or a systolic blood pressure less than 0.2 times the.