Abstract 15893: Risk of Clinical Outcomes and Baseline Atrial Fibrillation: Irbesartan in Heart Failure With Preserved Ejection Fraction (I-PRESERVE) Trial
Background: Atrial fibrillation (AF) is common in heart failure patients with reduced or preserved ejection fraction (HFpEF). However, information about the relationships between AF and clinical outcomes in patients with HFpEF is limited. We examined these associations in 4128 patients with HFpEF and LVEF ≥ 45% in the I-PRESERVE Trial who were randomly assigned to either irbesartan or placebo.
Objectives: To determine the risk of adverse clinical outcomes when AF was present on the baseline electrocardiogram (ECG) in the I-PRESERVE trial.
Methods: Baseline characteristics of patients with and without AF were compared. Cox regression models were used to estimate hazard ratios (HR) adjusting for 26 known prognostic variables including medications.
Results: Overall 670 (16%) had AF at baseline, of whom 97% had a history of AF as well. Compared to patients without AF, on average those with AF were older (74 vs 71 years) male (46% vs 38%), and less likely to have ischemic etiology for their heart failure (17% vs 25%) and left ventricular hypertrophy on their ECG (24% vs 32%). Their symptoms as assessed by the NYHA class were worse and they had a 5-fold higher median NT-proBNP concentration (1319 vs 260 pg/ml). Patients with AF were more likely to be treated with antiarrhythmics (12% vs 8%), diuretics (93% vs 81%) and anticoagulants (65% vs 10%) and less likely to be on antiplatelet agents (34% vs 63%) but equally treated with beta-blockers. Patients with AF had a 35% higher (95% CI: 12-62) adjusted hazard ratio (HR) for all-cause mortality; 60% higher (95% CI: 33-92) for cardiovascular death or HF hospitalization; 63% higher (95% CI: 10-142) for stroke and 63% higher (95% CI: 34-98) for HF hospitalization. AF was not associated with an increased risk of non-cardiovascular hospitalization (HR 1.04; 95% CI: 0.81- 1.12). The effect of irbesartan did not differ between patients with and without AF (p>0.6 for interaction between AF and treatment for all out comes).
Conclusion: In patients with HFpEF, AF seen on the baseline ECG was independently associated with an increased risk of mortality and cardiovascular morbidity. Strategies to reduce AF in HFpEF might improve outcomes in these patients.
- © 2013 by American Heart Association, Inc.