Influence of renal impairment on myocardial function in outpatients with systolic heart failure: an echocardiographic and cardiac biomarker study

Abstract

Background: Renal dysfunction (RD) is associated with poor outcome in systolic heart failure (HF). Left ventricular ejection fraction (LVEF) is not depressed to a greater extent in patients with RD compared to patients with normal renal function, but it is relatively unknown whether other measures of myocardial function are impaired by RD. The objective of the present study is to evaluate whether RD in systolic HF is associated with excessive impairment of myocardial function, evaluated by strain analysis and cardiac biomarkers.

Methods: Patients with LVEF <0.45% were enrolled from an outpatient HF clinic. The patients underwent advanced echocardiography. Glomerular filtration rate was estimated by the CKD-EPI equation (eGFR) and patients grouped by eGFR: eGFR group-I, ≥ 90 ml/min/1.73 m(2); eGFR group-II, 60-89 ml/min/1.73 m(2); and eGFR group-III, ≤ 59 ml/min/1.73 m(2). Multivariate regression models were developed to evaluate the associations between eGFR groups, echocardiographic measures and cardiac biomarkers.

Results: A total of 149 patients participated in the study. Median age was 69 years, 26% were female; LVEF was 33%. Patients with a low eGFR were older (P < 0.001), but there were no differences in frequency of atrial fibrillation, hypertension, diabetes and ischemic heart disease between eGFR groups (P > 0.05 for all). RD was associated with impaired global longitudinal strain (P = 0.018), increased E/e' (P = 0.032), larger left atria (P = 0.038) and increased levels of proANP (P < 0.001), NT-proBNP (P < 0.001) and troponin I (P = 0.019) after adjustment for traditional confounders.

Conclusions: Echocardiographic measures and biomarkers reflecting different aspects of myocardial function are impaired in systolic HF patients with RD and the increased mortality risk in these patients may partly be explained by a depressed cardiac function.

Keywords: Cardiorenal syndrome; Echocardiography; Global longitudinal strain; Left atrial volume index; Renal function; Systolic heart failure.