Renal artery denervation helps reduce AF recurrence

Renal artery denervation reduced the recurrence of atrial fibrillation (AF) in patients with paroxysmal or persistent AF and drug-resistant hypertension when combined with pulmonary vein isolation (PVI). The denervation group in the randomized study published Sept 25 in the Journal of the American College of Cardiology also experienced significant reductions in blood pressure.

“Hypertension is an important risk factor for developing atrial fibrillation (AF); the incidence of AF also increases with left ventricular (LV) hypertrophy, coronary heart disease, and heart failure, all consequences of poorly controlled hypertension,” wrote Evgeny Pokushalov, MD, PhD,  of the State Research Institute of Circulation Pathology in Novosibirsk, Russia, and colleagues. “We hypothesized that renal artery denervation could have a salutary effect on AF patterns in patients with poorly controlled hypertension by improving blood pressure control and by reduction in central sympathetic cardiac stimulation.”

Pokushalov et al designed a prospective, randomized double-blind trial using patients with a history of symptomatic drug-refractory paroxysmal or persistent AF and drug-resistant hypertension. The study compared patients treated with PVI and renal artery denervation (13 patients) with those who received only PVI (14 patients). All patients were followed for one year. Neither the patients nor their follow-up care physicians knew who received which procedure.

The primary endpoint was recurrence of atrial tachyarrhythmia of 30 seconds or more after a single ablation period following the first three months of ablation. Secondary endpoints included blood pressure readings in the office setting and safety data before and at three, six, nine and 12 months after the procedure.

At the one-year follow-up, 69 percent of the PVI and renal artery denervation group remained AF-free compared with 29 percent of the PVI only group. Patients in the PVI only group showed no significant changes in systolic or diastolic blood pressure. The PVI and renal artery denervation group, on the other hand, had significant decreases in systolic and diastolic blood pressure at three, six, nine and 12 months. At 12 months, the mean reductions were systolic and diastolic blood pressure were 25 mm Hg and 10 mm Hg, respectively, compared with baseline.

“Atrial fibrillation ablation is a well-known and accepted therapy for symptomatic patients with PAF [paroxysmal  AF]or PersAF [persistent AF],” they wrote. “Our data, albeit from a small patient cohort, show an independent contribution of renal denervation to eliminating AF recurrences in hypertensive and drug-resistant patients.”

Pokushalov et al added that previous research has shown AF patients with drug-resistant hypertension are at high risk for arrhythmia recurrence after PVI , and that research using hypertensive animal models highlighted a progressive  increase in conditions such as atrial inflammation. “On the basis of this evidence, our results underline the partially reversible impact of elevated blood pressure on AF burden if patients also undergo PVI,” they concluded.

They noted that theirs was a first-in-man trial with a small enrollment whose results needed to be validated in a larger study. Their trial also followed patients for only one year and results could not be extended to long-term sinus rhythm maintenance and hypertension control.

In an accompanying editorial, Ralph J. Verdino, MD, of the Hospital of the University of Pennsylvania in Philadelphia, pointed out that the study may not be comprehensive because it failed to document arrhythmia recurrence continuously in an ambulatory setting. Nonetheless, he described the findings as impressive.

He added that the study raises many questions, including whether renal artery denervation should be performed instead of PVI. “This study also allows one to wonder whether improved pharmacologic control of hypertension can decrease AF recurrences after catheter ablation of AF or even instead of performing this procedure,” Verdino suggested. “Maybe with better control of hypertension, however we physiologically achieve it, we can indeed improve the success rates of catheter ablation of the atria or decrease the need to ever perform this procedure in many patients.”