Abstrakt
BACKGROUND: In prior unblinded studies, cardiac neuromodulation therapy (CNT) employing a sequence of variably timed short and longer atrioventricular intervals yielded sustained reductions of systolic blood pressure (SBP) in patients with hypertension. The effects of CNT on SBP were investigated in this double-blind randomized pilot study.
METHODS AND RESULTS: Eligible patients had daytime ambulatory SBP (aSBP) >= 130 mm Hg and office SBP >= 140 mm Hg despite taking >= 1 antihypertensive medication, and an indication for a dual-chamber pacemaker. Patients underwent Moderato device implantation, which was programmed as a standard pacemaker during a 1-month run-in phase.
Patients whose daytime aSBP was >= 125 mm Hg at the end of this period were randomized (1:1, double blind) to treatment (CNT) or control (CNT inactive). The primary efficacy end point was the between-group difference of the change in 24-hour aSBP at 6 months.
Of 68 patients initially enrolled and who underwent implantation with the Moderato system, 47 met criteria for study continuation and were randomized (26 treatment, 21 control). The mean age was 74.0 +/- 8.7 years, 64% were men, left ventricular ejection fraction was 59.2%+/- 5.7%, and aSBP averaged 141.0 +/- 10.8 mm Hg despite the use of 3.3 +/- 1.5 antihypertensive medications; 81% had isolated systolic hypertension.
Six months after randomization, aSBP was 11.1 +/- 10.5 mm Hg (95% CI, -15.2 to -8.1 mm Hg) lower than prerandomization in the treatment group compared with 3.1 +/- 9.5 mm Hg (-7.4 to 1.2 mm Hg) lower in controls, yielding a net treatment effect of 8.1 +/- 10.1 mm Hg (-14.2 to -1.9 mm Hg) (P=0.012). There were no Moderato device- or CNT-related adverse events.
CONCLUSIONS: CNT significantly reduced 24-hour aSBP in patients with hypertension with a clinical indication for a pacemaker. The majority of patients had isolated systolic hypertension, a particularly difficult group of patients to treat.