Circadian variation in patients with acute heart failure with preserved ejection fraction.

Background: The circadian system influences the pathophysiology of many cardiovascular diseases; however, circadian variations in patients with heart failure with preserved ejection fraction (HFpEF) are unknown. Thus, this study aimed to compare the clinical characteristics and risk factors for in-hospital mortality between patients with daytime- versus nighttime-onset HFpEF.

Methods: This multicenter retrospective study included 3875 consecutive patients with acute HFpEF. Daytime and nighttime periods were defined as 6:00-17:59 and 18:00-5:59, respectively. Potential prognostic factors for in-hospital mortality were selected using univariable analyses. Those with P values of <0.10 were used in multivariable logistic regression analyses with forward selection (likelihood ratios) to identify significant prognostic factors.

Results: The incidence of daytime-onset HFpEF was significantly lower but the in-hospital mortality was significantly higher than that of nighttime-onset HFpEF. Independent prognostic factors for in-hospital mortality in patients with daytime-onset HFpEF were age (odds ratio [OR], 1.057) and systolic blood pressure (OR: 0.979). In contrast, age (OR: 1.067), coexisting atrial fibrillation/flutter (OR: 2.023), systolic blood pressure (OR: 0.989), estimated glomerular filtration rate (OR: 0.971), treatment with diuretics (OR: 0.282), and treatment with beta-blockers (OR: 0.514) were independent prognostic factors in patients with nighttime-onset HFpEF.

Conclusions: The incidence of acute HFpEF exhibits circadian variations, and onset-related differences in clinical characteristics and prognostic factors for in-hospital mortality were identified. These findings may provide new insights for future research and guide individualized patient management strategies.