Excess renin is attributed to the combination of forward and backward failure in HFrEF

Aims Regulation of the renin‐angiotensin system (RAS) in heart failure (HF) with reduced ejection fraction (HFrEF) still raises questions, as a large proportion of patients show normal renin levels despite manifest disease. Experimental venous congestion results in reduced renal perfusion pressure and stimulates renin secretion. We hypothesized that excess renin levels are mainly a result of right ventricular failure as a sequalae of left ventricular dysfunction. The study aimed to link right ventricular function (RVF) with renin levels and to investigate further contributors to excess RAS activation. Methods and results Three hundred thirty‐two chronic HFrEF patients undergoing routine ambulatory care were consecutively enrolled in a prospective, registry‐based, observational study. Laboratory parameters, including cardiac‐specific markers renin, aldosterone, and N‐terminal pro‐brain natriuretic peptide (NT‐proBNP), echocardiographic examination (n = 247), and right heart catheterization (n = 85), were documented. The relationship between renin and its respective parameters was analysed. Renin concentration was not associated with the New York Heart Association class or NT‐proBNP. Systolic blood pressure, systemic vascular resistance, serum sodium, aldosterone, and lactate dehydrogenase were associated with increased renin levels (P