Acute Heart Failure and Atrial Fibrillation: Insights From the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (ASCEND-HF) Trial

BACKGROUND Patients with acute heart failure (AHF) frequently have atrial fibrillation (AF), but how this affects patient-reported outcomes has not been well characterized. METHODS AND RESULTS We examined dyspnea improvement and clinical outcomes in 7007 patients in the Acute Study of Clinical Effectiveness of Nesiritide in Decompensated Heart Failure (ASCEND-HF) trial. At baseline, 2677 (38.2%) patients had current or a history of AF and 4330 (61.8%) did not. Patients with a history of AF were older than those without (72 vs. 63 years) and had more comorbidities and a higher median left ventricular ejection fraction (31% vs. 27%, P<0.001). Compared to those without AF, patients with AF had a similar mean ventricular rate on admission (81 vs. 83 beats per minute [bpm]; P=0.138) but a lower rate at discharge (75 vs. 78 bpm; P<0.001). There was no difference in dyspnea improvement between patients with and without AF at 6 hours (P=0.087), but patients with AF had less dyspnea improvement at 24 hours (P<0.001). Compared to patients without AF, patients with AF had a higher 30-day all-cause mortality rate (4.7% vs. 3.3%; P=0.005), a higher 30-day HF rehospitalisation rate (7.2% vs. 5.3%; P=0.001), and a higher coprimary composite outcome of 30-day death or readmission (11.6% vs. 8.6%; P<0.001). This difference persisted after adjustment for prognostic variables (adjusted odds ratio=1.19; (95% confidence interval, 1.02 to 1.38; P=0.029). CONCLUSIONS Among patients admitted to the hospital with AHF, current or a history of AF is associated with less dyspnea improvement and higher morbidity and mortality at 30-days, compared to those not in AF. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT00475852.