Coronary microvascular dysfunction in patients with heart failure with reduced and mildly reduced ejection fraction: results from the PANACEA study

Abstract Aims Coronary microvascular dysfunction (CMD) is common and associated with impaired survival in patients with heart failure with preserved ejection fraction (HFpEF). In patients with heart failure with reduced ejection fraction (HFrEF) and mildly reduced ejection fraction (HFmrEF) the impact of CMD is not fully known. Purpose We aimed to investigate the prevalence of CMD and its association with phenotype, biomarkers, endothelial function and echocardiographic measurements in patients with HFrEF or HFmrEF. Method A prospective, exploratory bi-center study in patients with chronic stable heart failure, New York Heart Association (NYHA) Class II-IV, and ejection fraction (EF) <50% was performed. Study procedures included echocardiography, adenosine-based transthoracic Doppler echocardiography to assess coronary flow reserve (CFR), physical examination, fasting blood and urine sample, pulse wave velocity (PWV) and hemodynamic measurements. The cutoff of CFR<2.5 was used to diagnose CMD. A multivariable linear regression analysis with CFR as dependent variable, adjusted for age, sex, body mass index, smoking, atrial fibrillation and left ventricular mass, was performed to explore biomarkers, endothelial function, and echocardiographic measurements associated with CMD. Results Of 112 included patients, 87 (78%) were men, with a mean age of 73.3 (±7.5) years. Among patients with a successful CFR measurement (n=62), CMD was present in 40 (65%), mean age of 75.4 (±5.8) years (Table 1). Patients with CMD had higher N-terminal pro B-type natriuretic peptide (NTproBNP) and Troponin T (p<0.05), and more often HFrEF ( p=0.06). Patients with CMD had larger ventricles with greater left ventricular mass and larger end-diastolic volumes (p<0.05). In a linear regression analysis CMD was associated with higher NTproBNP, lower EF, PWV and global strain (table 2). Conclusion CMD was common and present in two thirds of patients with HFrEF or HFmrEF. Further CMD was associated with markers of more severe heart failure and systemic endothelial dysfunction indicating that CMD may be an important predictor of outcome in patients with HFrEF and HFmrEF.