Systemic hypertension after cardiac transplantation: effect of cyclosporine on the renin-angiotensin-aldosterone system.

Fifteen patients who had undergone cardiac transplantation and who had hypertension (164 +/- 14/112 +/- 13 mm Hg), aged 16 to 57 years (mean 39), were treated with cyclosporine, 8 +/- 3 mg/kg/day, and prednisolone, 0.27 +/- 0.1 mg/kg/day, for 63 to 788 days (mean 288) after transplantation. They were not given antihypertensive drugs. Before treatment, the mean urinary sodium level was 104 +/- 48 mEq/day. Two discrete abnormalities accompanied their high blood pressure (BP): an increase in serum creatinine levels (p less than 0.05) to values exceeding those measured just before transplantation (2.1 +/- 1.0 vs 1.35 +/- 0.54 mg/dl) with low creatinine clearance (61 +/- 28 ml/min X 1.73 m2), and a 15% increase in plasma volume (+445 +/- 686 ml, p less than 0.02). Urinary excretion of vanilmandelic acid and total metanephrines was normal. Supine plasma renin activity was also normal (0.78 +/- 0.32 nmol/ml/hour). The stimulation of renin release after acute inhibition of converting enzyme by captopril was less marked than is usual in hypertensive subjects (0.86 +/- 0.54 nmol/liter/hour). Captopril induced a smaller drop in BP than nifedipine (-8 +/- 13/-6 +/- 10 mm Hg vs -14 +/- 11/-15 +/- 10 mm Hg). Levels of plasma aldosterone, angiotensinogen and converting enzyme activity were all normal, 308 +/- 147 pmol/liter, 712 +/- 164 nmol/ml and 30 +/- 6 mU/ml, respectively. It is concluded that hypertension is common in cardiac transplantation patients treated with cyclosporine, since 13 of our 15 subjects were normotensive before transplant.(ABSTRACT TRUNCATED AT 250 WORDS)