REGRESSION OF LEFT-VENTRICULAR HYPERTROPHY IN HYPERTENSIVE HEART-TRANSPLANT RECIPIENTS TREATED WITH ENALAPRIL, FUROSEMIDE, AND VERAPAMIL

Background. This prospective study was designed to examine whether left ventricular (LV) hypertrophy of the denervated transplanted heart may be reversed by medical therapy and, if so, to investigate the time course of this process and its effect on exercise capacity, myocardial function, and cardiac hemodynamics. Methods and Results. Ten hypertensive heart transplant recipients with LV hypertrophy were evaluated before therapy with enalapril plus furosemide alone or combined with verapamil, at initial blood pressure (BP) control and after 3, 6, 9, and 12 months, using 24-hour noninvasive ambulatory BP monitoring, M-mode and two-dimensional echocardiography, and supine bicycle ergometry. Average 24-hour systolic and diastolic BP declined from 158 +/- 10 and 104 +/- 7 mm Hg to 129 +/- 9 and 84 +/- 10 mm Hg at initial BP control (p < 0.005 and p < 0.025, respectively) and total peripheral resistance from 1,687 +/- 177 to 1,376 +/- 122 dyne.sec.cm-5 (p < 0.025), remaining normal thereafter. Exercise capacity remained unchanged during the study. LV mass, mass-to-volume ratio, and end-diastolic septal plus posterior wall thickness decreased progressively from 211 +/- 30 g, 2.49 +/- 0.62 g/ml, and 25.7 +/- 2.6 mm to 184 +/- 26 g, 2.22 +/- 0.46 g/ml, and 22.5 +/- 1.9 mm after 3 months (all p < 0.025) and to 174 +/- 25 g, 2.07 +/- 0.38 g/ml, and 21.5 +/- 1.5 mm after 6 months (all p < 0.005), remaining unaltered at 9 and 12 months. A correlation was found between the decrease in average 24-hour mean BP and LV mass after 3 months of antihypertensive therapy (r = 0.71, p < 0.05). Systolic meridional wall stress, LV end-diastolic and stroke volume, ejection fraction, and cardiac output remained unchanged throughout the observation period. Conclusions. The results indicate that regression of LV hypertrophy is induced by effective antihypertensive therapy in the denervated transplanted heart. The extent of decrease in average 24-hour BP appears to be the main determinant for the extent of reduction in LV mass. LV afterload as characterized by systolic meridional wall stress, LV size and pump function, and physical exercise capacity of the transplant patients are not influenced by the therapeutic regimen chosen in this study.