Researchers in Australia have found that aggressive management of cardiovascular risk factors and weight can impact dramatically the long-term success rate of freedom from atrial fibrillation following ablation.
Results of the ARREST AF (Aggressive risk factor reduction study for atrial fibrillation) study were presented by Rajeev K Pathak (Centre for Heart Rhythm Disorders, University of Adelaide and Royal Adelaide Hospital, Adelaide, Australia) at the 35th Heart Rhythm Society (HRS) Annual Scientific Sessions (7–10 May, San Francisco, USA).
The study, winner of HRS’s Eric Prystowsky abstract award in the category of clinical research, demonstrated that patients who underwent aggressive management of cardiometabolic risk factors had nearly a five-fold greater probability of arrhythmia free survival (95% confidence interval: 2.04-11.4, p<0.001).
Pathak, who works as a research fellow in the laboratory of Prash Sanders in Adelaide, Australia, told delegates: “The long-term outcomes of atrial fibrillation ablation demonstrate attrition. We hypothesised that this attrition is due to a progressive substrate promoted by traditional cardiovascular risk factors. “Therefore, he said, this study was designed to evaluate the impact of risk factor and weight management on the outcomes of atrial fibrillation ablation.
A previous study, led by Sanders, (Hany Abed et al, JAMA 2013;310(19):2050-2060), found that a structured weight management programme for highly symptomatic patients with atrial fibrillation reduced symptom burden and severity and reduced antiarrhythmic drug use when compared with conventional care. These beneficial effects, they wrote, “may be attributable to decrease in left atrial area and ventricular wall thickness, thereby reducing the left atrial hypertension that is a common finding in obese patients.”
In ARREST AF, 149 patients (41% with non-paroxysmal atrial fibrillation) were included in the study after their first ablation. The inclusion criteria required patients with a body-mass index (BMI) of ≥27kg/m2 and one cardiovascular risk factor such as hypertension, diabetes, sleep apnoea, or abdominal lipids.
Pathak explained that all patients enrolled were offered aggressive risk factor management- which addressed weight, hypertension, diabetes, sleep apnoea, cholesterol, alcohol use and smoking-in a physician-led clinic directed at risk factor control in accordance with American Heart Association / American College of Cardiology guidelines. Of those, 61 patients accepted the risk factor management strategy while the remaining 88 refused and served as controls.
He said that the groups had similar baseline characteristics and were followed up for nearly two years after atrial fibrillation ablation. Patients had clinic review and seven-day Holter monitoring at three-six monthly intervals. The absence of any arrhythmia ≥30 seconds and change in atrial fibrillation symptom score (frequency, duration, severity and symptom severity) were determined.
Results
Pathak said that patients treated with the aggressive risk factor management strategy experienced greater reduction in weight (-12.1±1 vs.-1.5±0.8), systolic blood pressure (-34±8 vs. -20.5±3mmHg), better glycemic control (HbA1c; p=0.001) and lipid profile (LDL/TG; p=0.01).
At follow up, atrial fibrillation frequency, duration, severity and symptom severity decreased more in the aggressive risk factor management group compared to controls. Pathak highlighted that single procedure drug-unassisted arrhythmia free survival was greater in the risk factor management arm compared to controls (32.9% vs. 9.7 %) and multiple procedure arrhythmia free survival was “markedly better” in the risk factor management group compared to controls (87% vs. 17.8%) with 16% of risk factor management patients and 42.4% of controls using anti-arrhythmic drugs.
On multivariate analysis, both the type of atrial fibrillation and risk factor management were independent predictors of outcome, he highlighted.
In conclusion, Pathak said that aggressive risk factor management significantly improves the long-term success of atrial fibrillation ablation. “This study underscores the importance of therapy directed at the primary promoters of the atrial fibrillation substrate to facilitate rhythm control strategies.”
Sanders told Cardiac Rhythm News that in light of these results current guidelines need to be changed including risk factor management for any attempt of rhythm control.
