HYPERTENSION PROPHYLAXIS WITH OMEGA-3-FATTY-ACIDS IN HEART-TRANSPLANTRECIPIENTS

Objectives. This study sought to determine whether omega-3 fatty acids act as hypertension prophylaxis in heart transplant recipients and ha ve an impact on vascular reactivity. Background. Cyclosporine-induced hypertension is probably related to endothelial dysfunction. Suggested vasodilatory mechanisms of omega-3 fatty acids may therefore be parti cularly beneficial in heart transplant recipients. Methods. Heart tran splant recipients were randomized to receive either 4 g of omega-3 fat ty acids (treatment group, n = 14) daily or corn oil (placebo group, n = 14) from the fourth postoperative day. Twenty-four hour blood press ure monitoring was performed at day 12 and 1, 2, 3 and 6 months postop eratively. Microvascular endothelium-dependent vasodilation, evaluated by skin laser Doppler perfusion measurements of postocclusive reactiv e hyperemia, was determined preoperatively and at the end of the study . Results. With comparable characteristics at the time of randomizatio n, blood levels of cyclosporine did not at any point differ between th e groups. After 6 months, systolic blood pressure decreased 2 +/- 4 mm Hg (mean a SEM) in the treatment group and increased 17 +/- 4 mm Hg i n the placebo group (p < 0.01), whereas diastolic blood pressure incre ased 10 +/- 3 and 21 +/- 2 mm Hg (p < 0.01), respectively. The decreas e in systolic blood pressure was inversely proportional to increases i n concentrations of serum eicosapentaenoic and docosahexaenoic acid (p = 0.01). After 6 months, five patients in the treatment group and nin e in the placebo group needed additional antihypertensive treatment. A lthough the endothelial-dependent phase of the reactive hyperemic resp onse remained unchanged in the treatment group, it decreased significa ntly in the placebo group. Conclusions. Postoperative daily administra tion of 4 g of omega-3 fatty acids in heart transplant recipients is e ffective as hypertension prophylaxis, depending on increases in serum eicosapentaenoic and docosahexaenoic acids. Preservation of microvascu lar endothelial function, demonstrated by a more pronounced response t o forearm skin ischemia in the treatment group, may contribute to the hypotensive role of omega-3 fatty acids. (C) 1997 by the American Coll ege of Cardiology.