25 In Heart Failure with Preserved Ejection Fraction (HFPEF), Cardiovascular Magnetic Resonance Imaging (CMR) Detects New, Alternative Diagnoses which Carry Prognostic Significance

Introduction Heart failure with preserved ejection fraction (HFPEF) carries poor prognosis and definitive therapies are lacking. Transthoracic echocardiography (TTE) remains the primary diagnostic modality in HFPEF. We aimed to evaluate the diagnostic and prognostic utility of cardiovascular magnetic resonance (CMR) in HFPEF. Methods Patients were recruited as part of Developing Imaging And plasMa biOmarkers iN Describing-HFPEF (DIAMOND-HFPEF): a prospective, single-centre study. Inclusion criteria were: clinical or radiographic evidence of heart failure (HF) and ejection fraction > 50% on TTE. Exclusion criteria were: myocardial infarction (MI) in the preceding 6 months, suspected or confirmed cardiomyopathy, constrictive pericarditis, non-cardiovascular life expectancy Results 154 patients (mean age 72.4 ± 10.0 years, 51% Male) underwent both CMR and TTE. CMR detected the following previously unknown diagnoses (total n = 42): significant coronary artery disease (n = 16, including 14 with 9silent9), microvascular dysfunction (n = 11), hypertrophic cardiomyopathy (n = 10) and constrictive pericarditis (n = 5). During follow-up (median = 623 days, interquartile range 455 -– 753), there were 53 primary outcome events. Kaplan-Meier survival analysis (see Figure 1) revealed worse outcomes in the 9new diagnoses group9 (Log Rank test p = 0.046). In a multivariate Cox Regression model comprising significant independent predictors during univariate analysis (diastolic blood pressure, NHYA class, urea, eGFR and log BNP), the ‘new diagnoses group’ (hazard ratio [HR]: 1.917; 95% confidence interval [CI]: 1.064 to 3.454; p = 0.03) remained a significant independent predictor of primary outcomes (see Figure 2). Conclusion In HFPEF, CMR identifies previously unknown pathologies in a significant minority (>25%). This group of ‘new diagnoses’ is associated with worse outcomes and is an independent predictor of death and/or re-hospitalisation with HF.