[op.4a.10] renal denervation versus spironolactone in resistant hypertension. effects on circadian patterns and blood pressure variability

Objective: We have previously reported that spironolactone (S) was superior to renal denervation (RD) in reducing 24-hour blood pressure in resistant hypertensive subjects. The present analysis examines the effect of both treatments on daytime and nighttime values, as well as in blood pressure variability (BPV). Design and method: Randomised, clinical trial in resistant hypertensives (office SBP > 150 and 24-h SBP > 140 mmHg). After eligibility, 24 patients were assigned to S (13) at a dose of 50 mg/day or RD (11). A 24-h ABPM was performed at baseline and after 6 months. Circadian effects were analysed by computing daytime (08:00–22:00) and nighttime (00:00–06:00) BP and heart rate (HR), as well as night-to-day ratios. Measures of BPV included standard deviations (SD) and coefficient of variation (CV) for 24-h, day and night BP and HR, as well as weighted SD and average real variability (ARV). Differences between baseline and final ABPM were calculated. The effect of treatment was examined by generalized linear models adjusted by baseline values (for circadian values) and for the correspondent difference in BP or HR (for BPV). Results: Spironolactone was superior to RD in reducing daytime SBP (25.6 vs 3.4 mmHg; p = 0.006) and DBP (10.3 vs 1.8 mmHg; p = 0.006), and nighttime SBP (23.4 vs 7.1 mmHg; p = 0.050). No differences were observed between treatments in night-to-day ratios of BP or HR. DBP variability was reduced with RD in comparison to S. This was observed for both SD and CV for 24-h, day and night values, as well as for weighted SD (p = .013) and ARV (p = 0.023). No differences were observed between treatments in changes in SBP or HR indexes of variability. Conclusions: Spironolactone is superior to RD in reducing day and night BP, without differences in the circadian pattern. RD reduces diastolic BPV in comparison to S. The importance of this effect should be further examined in terms of possible prognostic implications.