Vasodilatation with felodipine in chronic asymptomatic aortic regurgitation

Background Afterload reduction decreases volume overload on the left ventri cle and may thereby delay the need for valve replacement in chronic asympto matic aortic regurgitation. The aims of this randomized double-blind, place bo-controlled trial were to examine short- and long-term hemodynamic effect s of felodipine in chronic asymptomatic aortic regurgitation. Methods sixteen patients were randomly assigned to an intravenous infusion of either felodipine 0.3 mg or placebo Followed by 3 months' treatment with felodipine 10 mg or placebo orally once daily. Magnetic resonance imaging was performed at baseline, immediately after intravenous treatment, and aft er 3 months of oral treatment. Results Intravenous felodipine caused a statistically significant reduction in the systemic vascular resistance from (mean +/- SD) 1160 +/- 400 to 970 +/- 320 dynes . s . cm(-5) (P < .05), in the regurgitant volume index from 1.5 +/- 0.8 to 1.3 +/- 0.8 L . min(-1) m(-2) (P < .05), and in the regurgi tant fraction from 0.31 +/- 0.15 to 0.26 +/- 0.14 (P < .05). The forward ca rdiac output index increased significantly from 3.2 +/- 0.9 to 3.5 +/- 0.7 L . min(-1) . m(-2) (P < .05). Three months of oral treatment with felodipi ne caused a corresponding but more pronounced decrease in systemic vascular resistance of 880 +/- 330 dynes . s . cm(-5) (P < .05), regurgitant volume index of 1.2 +/- 0.7 L . min(-1) . m(-2) (P < .05), and regurgitant fracti on 0.25 +/- 0.11 (P < .05), whereas the forward cardiac output index increa sed to 3.6 +/- 0.7 L . min(-1) . m(-2) (P < .05). No significant changes we re found in the placebo group. left ventricular volumes and election Fracti on remained unaffected by treatment, but compared with the placebo group le ft ventricular myocardial mass decreased significantly from 137 +/- 24 to 1 32 +/- 21 g . m(-2) (P < .01). Conclusion In chronic asymptomatic aortic regurgitation, felodipine causes beneficial hemodynamic effects that may postpone the need for valve replace ment.