Long-term therapy with enalapril (MK-421) in congestive heart failure. Clinical, haemodynamic and echocardiographic evaluation

The real possibilities for the use of enalapril (MK-421) in the treatment of cardiac failure were studied, evaluating its effects on subjective and objective symptoms and also changes in haemodynamic parameters and in regional and global left ventricular functional parameters. These latter were measured by M-mode and two dimensional (2D) echocardiography. Ten patients with severe chronic congestive heart failure were studied for 12 weeks, divided into two stages: during the first stage (three weeks) each patient was treated with digitalis, diuretics and placebo, during the second (nine weeks) the placebo was replaced by enalapril 20 mg as a single oral dally dose. At the end of each stage, clinical, haemodynamic and echocardiographic parameters were examined. After the nine weeks' treatment with enalapril changes from pre-treatment conditions were seen: 1. (i) improvement in exercise tolerance in the six patients studied; 2. (ii) a statistically non-significant reduction in systemic arterial pressures; 3. (iii) a significant increase in the cardiac index; 4. (iv) a significant reduction in systemic vascular resistances, pulmonary pressures, pulmonary capillary wedge pressure and mean right atrial pressure; 5. (v) a significant reduction in left ventricular end diastollc diameter and left ventricular end systolic diameter with an increase in left ventricular fractional shortening; 6. (vi) a significant reduction in left ventricular diastolic volume and in left ventricular end systolic volume and an increase in left ventricular ejection fraction; and 7. (vii) a reduction in left ventricular end systolic wall stress. The results of the study clearly indicated the effectiveness of enalapril in improving the clinical and haemodynamic conditions of patients with severe congestive heart failure, without side-effects.