Abstract 3070: Obesity and Left Atrial Volume as Independent Risk Factors for the Progression of Paroxysmal Atrial Fibrillation to Persistent Atrial Fibrillation
Background: There is evidence that obesity is a risk factor for atrial fibrillation (AF). However, whether obesity is related to the progression from paroxysmal to persistent AF, independent of left atrial (LA) volume, is not known.
Methods: In this longitudinal cohort study, Olmsted County, Minnesota residents confirmed to have developed paroxysmal AF for the first time during 1980 –2000 were identified and followed passively to 2005. The relationships of body mass index (BMI) and LA size to conversion from paroxysmal to persistent AF were analyzed.
Results: Of a total of 3,248 patients (mean age 71 ± 15 years; 54% men) diagnosed with paroxysmal AF and followed for a mean of 5.5 ± 5 years, 557 converted to persistent AF (incidence of 31 per 1000 person years). Adjusting for age and sex, BMI was an independent predictor of conversion to persistent AF (HR 1.05, CI 1.03–1.06; p<0.0001). Compared to normal weight (BMI 18.5–24.9 kg/m2), obesity (30 –34.9 kg/m2) and severe obesity (≥35 kg/m2) were associated with increased risk for conversion (HR 1.4 ; CI, 1.1–1.7; p=0.0061 and HR 1.7; CI, 1.3–2.2; p=0.0003, respectively), even after multiple adjustments. In the subgroup with echocardiographic assessment (N=744), LA volume was incremental to BMI for the prediction of conversion, after multiple adjustments (HR 1.01; CI 1.00 –1.02; p<0.0001) and did not weaken the association of BMI with conversion to persistent AF.
Conclusions: Increased BMI was associated with a graded risk of conversion from paroxysmal to persistent AF. LA volume and BMI were incremental to each other, and independently predictive of the conversion to persistent AF.