Coronary microvascular dysfunction (CMD) is not confined to heart failure with preserved ejection fraction (HFpEF), but is also common in patients with reduced (HFrEF) and mildly reduced ejection fraction (HFmrEF). The PANACEA-HF study, published in Open Heart, investigated the prevalence of CMD and its association with disease severity in chronic HF.

The prospective explorative study enrolled 125 patients with stable symptomatic HF and LVEF <50%. Assessments included physical examination, blood biomarkers, Kansas City Cardiomyopathy Questionnaire (KCCQ), carotid–femoral pulse wave velocity, echocardiography, and adenosine-based transthoracic Doppler echocardiography to measure coronary flow reserve (CFR). CMD was defined as CFR <2.5.

Among 68 patients eligible for (CFR) assessment, (66%) were diagnosed with CMD. These patients demonstrated significantly higher NT-proBNP and hsTroponin-T levels, lower KCCQ scores, and impaired global longitudinal strain (GLS) across the left and right ventricles and the left atrium.

In multivariable analysis, lower LVEF, impaired right ventricular GLS, and higher biomarker levels independently predicted CMD. These results indicate that CMD is present in two-thirds of patients with HFrEF and HFmrEF and is closely linked to markers of more severe disease burden.