Abstract
BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is common yet diagnostically challenging in older adults presenting with acute dyspnoea to the emergency department (ED). This study evaluated the diagnostic performance of established markers used in HFpEF assessment, including echocardiographic indices, NT-proBNP, and the H(2)FPEF score, in identifying newly diagnosed HFpEF in this population. METHODS: Between September 2024 and May 2025, we conducted a prospective observational study of patients aged ≥60 years presenting to the ED of a tertiary hospital in Vietnam with acute dyspnoea. HFpEF was identified using the 2021 European Society of Cardiology (ESC) guidelines, which served as the gold-standard diagnostic framework. Baseline characteristics were compared between HFpEF and non-HFpEF groups, and the diagnostic performance of candidate markers was assessed using receiver operating characteristic curve analysis. RESULTS: Among 280 enrolled patients, 118 (42.1%) were newly diagnosed with HFpEF. Sociodemographic, geriatric, clinical, and comorbidity characteristics were comparable between groups. Patients with HFpEF had significantly higher NT-proBNP levels (median 2205 pg/mL vs 150 pg/mL, p<0.001), left ventricular mass index (LVMI) (118.0 ± 12.1 g/m(2) vs 93.4 ± 15.9 g/m(2), p<0.001), and H(2)FPEF scores (median 7 vs 4, p<0.001). NT-proBNP ≥760 pg/mL (AUC 0.979, 95% confidence interval [CI] 0.964-0.994; Youden index 0.91), LVMI ≥108 g/m(2) (AUC 0.889, 95% CI 0.851-0.927; Youden index 0.62), and an H(2)FPEF scores ≥6 (AUC 0.861, 95% CI 0.818-0.903; Youden index 0.71) demonstrated strong discriminatory performance. Diastolic indices alone showed poor discriminatory ability (AUC <0.55). CONCLUSION: In older adults presenting with acute dyspnoea, NT-proBNP, LVMI, and the H(2)FPEF score demonstrated good discriminatory ability for newly diagnosed HFpEF. However, the diagnostic performance of NT-proBNP and LVMI should be interpreted with caution, as both are included in the ESC diagnostic framework. Diastolic indices showed limited diagnostic value, likely because diastolic abnormalities were also common among non-HFpEF patients, highlighting an important methodological constraint.