Clinical Predictors of Heart Failure with Preserved Ejection Fraction Among Patients with Atrial Fibrillation: A Prospective Observational Study of 100 Patients

Background: Atrial fibrillation (AF) and heart failure with preserved ejection fraction (HFpEF) frequently coexist and share several clinical and pathophysiological risk factors. Diagnosis of HFpEF in patients with AF can be challenging because symptoms, natriuretic peptide concentrations and echocardiographic findings may be influenced by AF itself. Identification of clinically useful predictors may facilitate earlier recognition of HFpEF in patients with preserved left ventricular ejection fraction (LVEF).

Objective: To identify clinical, biochemical and echocardiographic predictors of HFpEF among patients with AF and preserved LVEF and to evaluate their diagnostic performance.

Methods: This observational study included 100 patients with documented AF and preserved LVEF. Participants were categorized into HFpEF (n=64) and non-HFpEF (n=36) groups according to predefined clinical and echocardiographic criteria. Demographic characteristics, cardiovascular risk factors, symptoms, laboratory parameters, NT-proBNP and comprehensive echocardiographic measurements were assessed. The H₂FPEF and HFA-PEFF scores were also evaluated. Univariable and multivariable logistic regression analyses were performed to identify independent predictors of HFpEF. Receiver operating characteristic (ROC) analysis was performed to assess the diagnostic performance of individual predictors and combined models.

Results: Patients with HFpEF were significantly older than non-HFpEF patients (69.8 ± 8.7 vs. 61.7 ± 9.2 years; P<0.001) and had higher BMI (29.1 ± 4.3 vs. 26.7 ± 3.6 kg/m²; P=0.004). Hypertension, diabetes mellitus, chronic kidney disease and persistent/permanent AF were significantly more frequent in the HFpEF group. Exertional dyspnea was present in 90.6% of HFpEF patients compared with 52.8% of non-HFpEF patients (P<0.001). NT-proBNP was substantially higher in the HFpEF group [1280 (760–2310) vs. 520 (260–920) pg/mL; P<0.001]. Despite comparable LVEF, HFpEF patients demonstrated greater LV mass index, relative wall thickness, left-atrial volume index (LAVI), E/e′ ratio, TR velocity and pulmonary artery systolic pressure (PASP). On multivariable analysis, age ≥65 years (adjusted OR [aOR] 2.81; 95% CI, 1.04–7.58), BMI ≥30 kg/m² (aOR 2.76; 95% CI, 1.01–7.54), hypertension (aOR 3.12; 95% CI, 1.10–8.83), NT-proBNP ≥900 pg/mL (aOR 3.69; 95% CI, 1.38–9.86), LAVI ≥34 mL/m² (aOR 6.84; 95% CI, 2.21–21.15), E/e′ ≥15 (aOR 5.71; 95% CI, 1.79–18.19) and PASP ≥35 mmHg (aOR 3.21; 95% CI, 1.11–9.27) were independent predictors of HFpEF. LAVI ≥34 mL/m² had an AUC of 0.80, while E/e′ ≥15 had an AUC of 0.78. The combined clinical model had an AUC of 0.84, which increased to 0.90 when echocardiographic variables were incorporated.

Conclusion: HFpEF was common among AF patients with preserved LVEF and was characterized by a distinct clinical, biochemical and echocardiographic phenotype. Older age, obesity, hypertension, elevated NT-proBNP, left-atrial enlargement, increased E/e′ and elevated PASP were independently associated with HFpEF. LAVI and E/e′ were particularly strong predictors, while the combined clinical and echocardiographic model demonstrated excellent discriminatory performance. A multidimensional assessment incorporating clinical risk factors, natriuretic peptides and echocardiographic markers may improve recognition of HFpEF in patients with AF.

Keywords: Atrial Fibrillation, Heart Failure With Preserved Ejection Fraction, HFpEF, NT-proBNP, Left Atrial Volume Index, E/e′, Pulmonary Artery Systolic Pressure, Echocardiography.