Prophylactic furosemide treatment in acute myocardial infarction.

Prophylactic diuretic therapy in acute myocardial infarction (AMI) was evaluated in 83 consecutive patients without severe left ventricular failure (LVF) on admission. A high dose group (HDG) received 120-160 mg and a low dose group (LDG) 20-40 mg furosemide daily for six weeks. Mortality and reinfarction rates did not differ between the groups. One HDG patient and five LDG patients developed severe LVF. Four HDG patients developed severe dehydration. Serum enzyme activities and electrolytes were similar in both groups. The increased diuresis in the HDG was accompanied by a 4% hemoconcentration, smaller radiological heart volumes, higher heart rates, a higher demand for nitroglycerin and higher ratings of thirst. Exercise tests yielded similar results in both groups. Later blood volumes and transthoracic electrical impedance were similar in both groups. It is concluded that liberal prophylactic furosemide treatment in AMI offers no major clinical advantage.