Archief Roodbont

RACE II: Lenient heart rate control in AF not inferior to strict control

Watch our Video Highlights interview on RACE II

MedWire News: Less rigorous control of heart rate in patients with permanent atrial fibrillation (AF) appears to be as effective as strict rate control at preventing serious adverse events, including death from all causes, reported investigators from the RACE II study at the 59th annual Scientific Sessions of the American College of Cardiology (ACC), in Atlanta, GA, USA, and online in the New England Journal of Medicine.

“Lenient rate control may be adopted as the first-choice rate control strategy in patients with permanent atrial fibrillation,” said Isabelle C. Van Gelder (University Medical Center Groningen and the Interuniversity Cardiology Institute in Utrecht, The Netherlands).This recommendation applies to patients both at high risk (CHADS 2 [congestive heart failure, hypertension, age >75 years, diabetes, and prior stroke] score 2-6).and low risk (CHADS 2 score 0-1) for complications from permanent AF.

The RACE II trial compared event rates for 311 patients randomized to lenient control (resting heart rate <110 beats per minute [bpm]) and 303 assigned to strict control (resting rate <80 bpm, exercise rate <110 bpm). The primary endpoint was a composite of cardiovascular mortality, heart failure (HF) hospitalization, stroke, systemic emboli, major bleeding, syncope, sustained venous thromboembolism, cardiac arrest, life-threatening adverse effects of rate-control drugs, and implantation of a pacemaker for bradycardia or of an implantable cardioverter defibrillator for ventricular arrhythmias.

Patients were treated with negative dromotropic agents, including beta-blockers, non-dihydropyridine calcium-channel blockers (verapamil or diltiazem), and digoxin, alone or in combination. Dosages were adjusted until the heart-rate target was achieved.

After 3 years of follow-up, the estimated cumulative incidence of adverse events was 12.9% in the lenient control group, vs 14.9% in patients on strict control (absolute difference of -2.0%, hazard ratio 0.84; neither difference was statistically significant). Deaths from any cause occurred in 5.6% of patients on lenient control and 6.6% on strict control.

At the end of follow-up, about 46% of patients in each group had symptoms associated with AF (including dyspnea, fatigue, and/or palpitations). About 70% in each group were in New York Heart Association functional class I, 23% were in class II, and 6.5% were in class III (p=0.74 for all comparisons). There were no significant differences in the frequency of hospitalization or of adverse drug-related events between the two groups.

Rates of individual adverse events within the primary composite endpoint were similar, although Van Gelder noted that the study was not powered to detect significant differences among the various components.

In a sub-group analysis by CHADS 2 score, fatal and nonfatal endpoints occurred in 4.5% of lenient group patients and 3.5% of strict group patients with CHADS 2 scores of <2. Among patients with scores of 2 or greater, 5.1% of lenient group patients and 10.0% of strict group patients had an event (p=0.02 for non-inferiority).

Free full text http://content.nejm.org/cgi/content/full/NEJMoa1001337v1