The Significance of Renal Function in Response to Cardiac Resynchronisation Therapy – A Piece of a Much Larger Puzzle

Abstract

Background: Although cardiac resynchronisation therapy (CRT) is an important player in the treatment of patients with heart failure (HF), the proportion of CRT patients with no improvement in either echocardiographic or clinical parameters remains consistently high and accounts for about 30% despite meeting CRT implantation criteria. Furthermore, in patients suffering from HF, renal dysfunction accounts for as many as 30-60%. Accordingly, CRT may improve renal function inducing a systemic haemodynamic benefit leading to increased renal blood flow. Objectives: The aim of the present study was to evaluate the importance of renal function in response to resynchronisation therapy during a 12-month follow-up period. Materials and Methods: The study consisted of 46 HF patients qualified for implantation of cardiac resynchronisation therapy defibrillator (CRT-D). A CRT responder is defined as a person without chronic HF exacerbations during observation whose physical efficiency has improved owing to the New York Heart Association (NYHA) class improvement ≥1. Results: A statistically significant difference was noted between responders and non-responders regarding creatinine level at the 3rd month (p=0.04) and, particularly, at the 12th month (p=0.02) of follow-up (100±23 vs 139±78 μmol/l). Moreover, there was a remarkable difference between both study groups with regard to GFR CKD-EPI (glomerular filtration rate (GFR) assessed using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula) at the 6th (p=0.03) and 12th month (p=0.01) of follow-up. The reference values for initial creatinine concentrations (101 μmol/l) as well as GFR CKDEPI (63 ml/min/1.73m2) were empirically evaluated to predict favourable therapeutic CRT response. Conclusions: Predictive value of GFR CKD-EPI and creatinine concentration for a positive response to CRT was found relevant.