Effects of Aliskiren, a Direct Renin Inhibitor, on Cardiac Repolarization and Conduction in Healthy Subjects

This multicenter, double-blind study evaluated the effects of aliskiren, a direct renin inhibitor approved for hypertension, on cardiac repolarization and conduction. Healthy volunteers (n = 298) were randomized to aliskiren 300 mg, aliskiren 1200 mg, moxifloxacin 400 mg (positive control), or placebo once daily for 7 days. Digitized electrocardiograms were obtained at baseline and day 7 of treatment over 23 hours postdose. Placebo-adjusted mean changes from baseline in QTcF (Fridericia corrected), QTcI (individualized correction), PR, and QRS intervals were compared at each time point (time-matched analysis) and for values averaged across the dosing period (baseline-averaged analysis). In time-matched analysis, mean changes in QTcF with aliskiren were below predefined limits for QTc prolongation (mean increase <5 milliseconds; upper 90% confidence interval [CI] <10 milliseconds) except aliskiren 1200 mg at 23 hours (5.2 milliseconds; 90% CI 2.2, 8.1). With moxifloxacin, significant QTcF prolongation occurred at most time points, confirming the sensitivity of the assay. Baseline-averaged analysis was consistent with time-matched analysis. Instances of QTcF interval >450 milliseconds or a >30-millisecond increase from baseline with aliskiren (< or = 1%) were similar or lower than placebo (< or = 4%). Results were similar for QTcI. Aliskiren had no effect on PR or QRS duration. In conclusion, aliskiren at the highest approved dose (300 mg) and a 4-fold higher dose had no effect on cardiac repolarization or conduction in healthy volunteers.