Aims: Several mechanisms have been identified in the aetiopathogenesis of heart failure with preserved ejection fraction (HFpEF). Among these, coronary microvascular dysfunction (CMD) may play a key pathophysiological role. We performed a systematic review and meta-analysis to investigate the prevalence, echocardiographic correlates, and prognostic implications of CMD in patients with HFpEF. Methods and results: A systematic search for articles up to 1 May 2023 was performed. The primary aim was to assess the prevalence of CMD. Secondary aims were to compare key echocardiographic parameters (E/e′ ratio, left atrial volume index [LAVi], and left ventricular mass index [LVMi]), clinical outcomes [death and hospitalization for heart failure (HF)], and prevalence of atrial fibrillation (AF) between patients with and without CMD. Meta-regressions according to baseline patient characteristics and study features were performed to explore potential heterogeneity sources. We identified 14 observational studies, enrolling 1138 patients with HFpEF. The overall prevalence of CMD was 58%. Compared with patients without CMD, patients with HFpEF and CMD had larger LAVi [mean difference (MD) 3.85 confidence interval (CI) 1.19–6.5, P < 0.01)], higher E/e′ ratio (MD 2.76 CI 1.54–3.97; P < 0.01), higher prevalence of AF (odds ratio 1.61 CI 1.04–2.48, P = 0.03) and higher risk of death or hospitalization for HF [hazard ratio 3.19, CI 1.04–9.57, P = 0.04]. Conclusions: CMD is present in little more than half of the patients with HFpEF and is associated with echocardiographic evidence of more severe diastolic dysfunction and a higher prevalence of AF, doubling the risk of death or HF hospitalization.

Family history for CAD (coronary artery disease) is an established cardiovascular (CV) risk factor and it is progressively acquiring importance in patients’ CV risk stratification. Numerous studies have demonstrated that individuals with a first-degree relative affected by CAD have a significantly higher risk of developing the condition themselves; in particular, when CAD occurs at an early age in relatives. Indeed, recently published CCS (chronic coronary syndrome) ESC (European Society of Cardiology) guidelines include family history (FH) as a risk factor to consider when calculating pre-test risk for CAD. ESC guidelines on preventive cardiology (2021) only suggested CV risk assessment in the presence of a positive FH for CV disease, not considering it in the actual risk scores. Evidence suggests that positive anamnesis for relatives affected by CAD correlates with ACS (acute coronary syndrome) and CAD, with slight differences in relative risk as far as the degree of kinship is concerned. Genetic factors contribute to this correlation by influencing key processes that affect heart health, such as cholesterol metabolism, blood pressure regulation, and inflammatory responses. New technologies in the genetics field are increasing the availability of genome sequencing, and new polymorphism panels are being tested as predictive for CAD, objectifying familiarity. Advances in imaging techniques allow the assessment of coronary atherosclerosis and its composition, and these are acquiring strength in evidence and recommendations in ESC guidelines as a way to define coronary disease in low and low-to-intermediate risk patients and to guide medical therapy and interventional procedures. Use of these emerging tools to guide screening is likely to be extended, beyond high CV risk patients, to individuals with FH for early CAD and/or specific genetic profiles, as recent evidence in the literature is suggesting.