A prospective study evaluating the role of obesity and obstructive sleep apnea for outcomes after catheter ablation of atrial fibrillation.

BACKGROUND: Obesity and obstructive sleep apnea (OSA) have a strong association with atrial fibrillation (AF). The purpose of this study was to prospectively determine the effects of obesity, assessed by the body mass index (BMI) and OSA on the efficacy of catheter ablation of AF. METHODS: The patient population consisted of 109 patients (mean age: 60 +/- 10 years, 79% male, 67% paroxysmal, mean BMI 28 +/- 5 kg/m(2)) who underwent catheter ablation of AF. Based on BMI, patients were classified as normal (<25 kg/m(2)), overweight (>or=25 and <30 kg/m(2)), or obese (>or=30 kg/m(2)). OSA was assessed by the Berlin questionnaire. Clinical success was defined as at least 90% reduction in AF burden after 3-month blanking period. Mean duration of follow-up was 11 +/- 4 months. RESULTS: Of the 75 patients with clinical success, 25 (33%) had normal BMI, 29 (39%) were overweight, and 21 (28%) were obese. Among the 34 patients with failed outcome, 5 (15%) had normal BMI, 14 (41%) were overweight, and 15 (44%) were obese (P = 0.04). Twenty-eight of the 48 patients with OSA (58%) had clinical success as opposed to 47 of the 61 patients (77%) without OSA (P = 0.036). On multivariate analysis, only BMI emerged as an independent predictor of procedural failure ((OR 1.11, CI: 1.00-1.21, P = 0.03). CONCLUSIONS: The results of this prospective study show that obesity, a modifiable risk factor, is an independent predictor of procedural failure after catheter ablation of AF. Whether treating obesity may improve the results of catheter ablation of AF warrants further investigation.

Incidence and outcomes of protamine reactions in patients undergoing catheter ablation of atrial fibrillation.

BACKGROUND: Aggressive anticoagulation with heparin to maintain an activated clotting time (ACT) >300 s is required during catheter ablation of atrial fibrillation (AF) to reduce the risk of systemic thromboembolism. The purpose of this study is to describe the incidence and outcome of protamine reactions and analyze the risk factors in patients undergoing catheter ablation of AF. METHODS: The patient population included 242 consecutive patients (193 men, age 57.6 +/- 10.8 years) with drug refractory AF who underwent catheter ablation and received protamine immediately following catheter ablation to reverse the effects of heparin. Fifty eight of these patients had prior exposure to protamine. RESULTS: Three of the 242 patients in our study developed an adverse reaction to protamine (1.2%). Although each of the three protamine reaction presented in a dramatic fashion with profound hypotension, all three patients responded to medical treatment and did not experience clinical sequelae. Age, gender, type of AF, number of ablations, prior exposure, diabetes mellitus, and ejection fraction did not predict the occurrence of these reactions. CONCLUSION: This study reports, for the first time, the incidence and outcomes of protamine reaction in patients undergoing catheter ablation of AF. The results of this study reveal that protamine reactions present in a dramatic fashion often with profound hypotension. Although the incidence of protamine reactions in this setting is low (1.2%), they do occur. Electrophysiologists who use protamine need to be aware of this reaction and the appropriate therapeutic interventions.