Clinical impact of insulin resistance on pulmonary vein isolation outcome in patients with paroxysmal atrial fibrillation

INTRODUCTION: The relationship between insulin resistance and atrial fibrillation (AF) recurrence after pulmonary vein isolation (PVI) remains unclear. METHODS: Drug-refractory 114 paroxysmal AF patients (89 males, 62 ± 8 years) who underwent successful PVI were enrolled. Homeostasis model assessment of insulin resistance (HOMA-IR) was calculated and a value of ≥2.5 was defined as insulin resistant. The left atrial volume index (LAVI) was measured using echocardiography before and 1 year after PVI. Tumor necrosis factor-α (TNF-α) and TGF-β1 serum levels were measured before PVI, and the left atrium (LA) conduction velocity was calculated. The patients were divided into two groups (group 1: HOMA-IR < 2.5, n = 81; group 2: HOMA-IR ≥ 2.5, n = 33). RESULTS: The LAVI between the two groups before PVI did not significantly differ (P > 0.05), nor did TNF-α (7.7 ± 2.0 vs 7.5 ± 1.0 pg/mL; P = 0.149) or TGF-β1 (28.4 ± 12.0 vs 27.6 ± 10.3 ng/mL; P = 0.757). LAVI before and 1 year after PVI in each group did not change. The conduction velocity of group 2 was slower than that of group 1 (0.7 ± 0.1 vs 1.1 ± 0.3 m/s, P < 0.001). Kaplan-Meier analysis showed significantly higher AF recurrence in group 2 than that in group 1 ( P = 0.019). Cox multivariable analysis revealed that insulin resistance was an independent predictor of recurrence (hazard ratio 1.287, P = 0.004). CONCLUSION: Our results suggest that insulin resistance promotes LA electrical remodeling and might be related to AF recurrence after PVI.