Type of Atrial Fibrillation and Outcomes in Patients With Heart Failure and Reduced Ejection Fraction.

BACKGROUND: Atrial fibrillation (AF) is common in heart failure (HF), but the outcome by type of AF is largely unknown.

OBJECTIVES: This study investigated outcomes related to type of AF (paroxysmal, persistent or permanent, or new onset) in 2 recent large trials in patients with HF with reduced ejection fraction.

METHODS: The study analyzed patients in the PARADIGM-HF (Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and morbidity in Heart Failure) and ATMOSPHERE (Aliskiren Trial to Minimize Outcomes in Patients with Heart Failure) trials. Multivariable Cox regression models were used to estimate hazard ratios (HRs) for outcomes related to AF type.

RESULTS: Of 15,415 patients, 5,481 (35.6%) had a history of AF at randomization, and of these, 1,645 (30.0%) had paroxysmal AF. Compared with patients without AF, patients with paroxysmal AF at randomization had a higher risk of the primary composite endpoint of cardiovascular death or HF hospitalization (HR: 1.20; 95% confidence interval [CI]: 1.09 to 1.32; p < 0.001), HF hospitalization (HR: 1.34; 95% CI: 1.19 to 1.51; p < 0.001), and stroke (HR: 1.34; 95% CI: 1.02 to 1.76; p = 0.037), whereas the corresponding risks in patients with persistent or permanent AF were not elevated. Neither type of AF was associated with higher mortality. New onset AF was associated with the greatest risk of adverse outcomes: primary endpoint (HR: 2.21; 95% CI: 1.80 to 2.71), HF hospitalization (HR: 2.11; 95% CI: 1.58 to 2.81), stroke (HR: 2.20; 95% CI: 1.25 to 3.88), and all-cause mortality (HR: 2.26; 95% CI: 1.86 to 2.74), all p values < 0.001, compared with patients without AF. Anticoagulants were used less often in patients with paroxysmal (53%) and new onset (16%) AF than in patients with persistent or permanent AF (71%).

CONCLUSIONS: Among HF patients with a history of AF, those with paroxysmal AF were at greater risk of HF hospitalization and stroke than were patients with persistent or permanent AF, underlining the importance of anticoagulant therapy. New onset AF was associated with increased risk of all outcomes. (Prospective comparison of ARNI with ACEI to Determine Impact on Global Mortality and Morbidity in Heart Failure [PARADIGM-HF]; NCT01035255) (Aliskiren Trial to Minimize Outcomes in Patients with Heart Failure [ATMOSPHERE]; NCT00853658).