Background: Lone atrial fibrillation (AF) has been suggested to have a favorable long-term prognosis. Significant interest has been directed at factors predicting arrhythmia progression, and the HATCH score (hypertension, age ≥ 75 years, transient ischemic attack or stroke [2 points], COPD, and heart failure [2 points]) recently has been proposed as a predictive score for AF progression. We investigated long-term outcomes in a large cohort of newly diagnosed lone AF and whether progression from paroxysmal to permanent AF confers an adverse impact on outcomes, including stroke and thromboembolism.
Methods: The study was an observational cohort of 346 patients with newly diagnosed lone AF with a mean follow-up of 12.1 ± 7.3 years.
Results: Baseline paroxysmal AF was confirmed in 242 patients, and of these, 65 (26.9%) subsequently experienced progression to permanent AF. Older age and development of congestive heart failure during follow-up were the multivariate predictors of AF progression (both P < .01), which was documented in 19.8% of patients with a HATCH score of 0 vs 63.2% with a score of 2 (P < .001), although the predictive validity of the HATCH score per se was modest (C statistic, 0.6). The annual rate of thromboembolism and heart failure during follow-up were low (0.4% each), and five patients (1.4%) died. AF progression, development of cardiac diseases, and older age were multivariate predictors of adverse outcomes, including thromboembolism (all P < .05). Baseline CHADS(2) (congestive heart failure, hypertension, age ≥ 75, diabetes mellitus, prior stroke or transient ischemic attack) score was not predictive for thromboembolism (C statistic, 0.50; 95% CI, 0.31-0.69).
Conclusions: This 12-year follow-up study provides confirmatory evidence of a generally favorable prognosis of lone AF, but adverse outcomes (including stroke and thromboembolism) are significantly influenced by age and the (new) development of underlying heart disease. Arrhythmia progression in lone AF is a marker of increased risk for adverse cardiovascular events.