Alternative Factors in Possible Involvement of Coronary Microvascular Dysfunction in Older Patients with HFpEF

<b>Objectives</b>: Coronary microvascular dysfunction (CMD) is associated with many heart diseases, including heart failure (HF) with preserved ejection fraction (HFpEF). Invasive examinations for CMD detection are difficult in older patients with HFpEF, and the decision criteria for noninvasive CMD measurements are unclear. We aimed to identify alternative factors in the possible involvement of CMD in the progression and prognosis of HFpEF. <b>Methods</b>: We analyzed 607 patients with HFpEF who were hospitalized for acute decompensated HF without a history of coronary artery disease (CAD). Blood tests and transthoracic echocardiography were performed. We focused on left ventricular hypertrophy (LVH) and coronary perfusion pressure (diastolic blood pressure, dBP). <b>Results</b>: The patients with LVH showed reduced diastolic function (E/e') and a lower incidence of atrial fibrillation (AF) compared with those without LVH, with no differences in age or dBP. No differences were observed in all-cause mortality between patients with low and high dBP without LVH. In the patients with LVH, the incidence of all-cause mortality was significantly higher, with a lower incidence of AF, reduced renal function, and higher C-reactive protein levels in those with low dBP than in those with high dBP. The comprehensive diastolic functional index, diastolic elastance/arterial elastance, was markedly higher in the patients with LVH, especially in those with all-cause mortality. This index, but not E/e', was a significant prognostic index in the multivariate Cox hazard analysis when adjusting for age, sex and N-terminal pro-brain natriuretic peptide levels. <b>Conclusions</b>: LVH and dBP were clinically important factors in elderly HFpEF patients without a history of CAD.