On-treatment HDL cholesterol predicts incident atrial fibrillation in hypertensive patients with left ventricular hypertrophy

Purpose: Hypertensive patients are at increased risk of atrial fibrillation (AF). Although low baseline high density lipoprotein (HDL) cholesterol has been associated with a higher risk of AF, this has not been verified in recent population-based studies. Whether changing levels of HDL over time are more strongly related to the risk of new AF in hypertensive patients has not been examined. Material and methods: Incident AF was examined in relation to baseline and on-treatment HDL levels in 8267 hypertensive patients with no history of AF, in sinus rhythm on their baseline electrocardiogram, randomly assigned to losartan- or atenolol-based treatment. HDL levels at baseline and each year of testing were categorised into quartiles according to baseline HDL levels. Results: During 4.7 ± 1.10 years of follow-up, 645 patients (7.8%) developed new AF. In univariate Cox analyses, compared with the highest quartile of HDL levels (>1.78 mmol/l), patients with on-treatment HDL in the lowest quartile (≤ 1.21 mmol/l) had a 53% greater risk of new AF. Patients with on-treatment HDL in the second and third quartiles had intermediate increased risks of AF. Baseline HDL in the lowest quartile was not a significant predictor of new AF (hazard ratio (HR): 1.14, 95% confidence interval (CI): 0.90-1.43). In multivariable Cox analyses adjusting for multiple baseline and time-varying covariates, the lowest quartile of on-treatment HDL remained associated with a nearly 54% increased risk of new AF (HR: 1.54, 95% CI: 1.16-2.05) whereas a baseline HDL≤ ⩽1.21 mmol/l was not predictive of new AF (HR: 1.01, 95% CI: 0.78-1.31). Conclusion: Lower on-treatment HDL is strongly associated with risk of new AF. These findings suggest that serial assessment of HDL can estimate AF risk better than baseline HDL in hypertensive patients with left ventricular hypertrophy. Future studies may investigate whether therapies that increase HDL can lower risk of developing AF. Clinical Trials Registration : http://clinicaltrials.gov/ct/show/NCT00338260?order=1