Abstract 3148: Atrial Fibrillation Is Associated With Increased Risk Of Fatal And Non-fatal Cardiovascular Events In Patients With Heart Failure And Preserved Ejection Fraction - Findings From The Irbesartan In Heart Failure With Preserved Systolic Function Trial (I-PRESERVE)
Background: Atrial fibrillation (AF, documented by ECG) is present in 15% of patients with heart failure and a reduced LV ejection fraction (HF-REF) and is an independent predictor of cardiovascular (CV) events. The prevalence of AF in patients with HF and preserved EF (HF-PEF) and whether AF is an independent predictor of CV outcomes in HF-PEF have not been defined.
Methods: The Irbesartan in Heart Failure with Preserved Systolic Function Trial (I-PRESERVE) randomized 4128 patients with an EF ≥ 45% to receive Irbesartan or placebo. The prevalence of AF was established by ECG at randomization. The “primary” outcome (475 events/3796 patients) of all-cause mortality or CV hospitalization (myocardial infarction, stroke, worsening heart failure, atrial or ventricular arrhythmia, unstable angina) and a “secondary” outcome (294 events/3796 patients) of HF mortality and HF hospitalizations were compared over one year of follow-up between patients with and without AF. The independent predictive role of AF was examined in a multivariable model (including symptoms, clinical history, CV examination, biochemistry, hematology).
Results: In I-PRESERVE, 16% of patients had AF by ECG at randomization. Patients with AF, compared to patients without AF, were older (74 ± 0.3 vs 71 ± 0.1 yrs, mean ± SEM), less often female (54% vs 62%), had lower EF (58 ± 0.4% vs 60 ± 0.2%), lower eGFR (68 ± 0.8 vs 73 ± 0.4), higher incidence of previous HF hospitalization (61% vs 41%), less frequent history of hypertension and MI (84 & 17% vs 89 & 25%), lower systolic BP (134 ± 0.6 vs 137 ± 0.3 mmHg), higher heart rate (76 ± 0.5 vs 71 ± 0.2 BPM), all p < 0.05. The primary and secondary outcomes occurred in 19 & 15% of patients with AF and 12 & 6% of patients without AF at 1 year. In a multivariate analysis AF remained a significant predictor of increased risk of the primary (Hazard Ratio, HR 1.33 [95% CI 1.07, 1.65]) and secondary (HR 1.81 [95% CI 1.40, 2.33]) outcomes.
Conclusions: At randomization to I-PRESERVE, the prevalence of AF by ECG in HF-PEF patients was similar to patients with HF-REF in previous studies. HF-PEF patients with AF had a significantly worse outcome than those without AF and this increased risk of fatal and non-fatal CV events was independent of other factors associated with a worse prognosis.