Impact of chronic kidney disease in CRT effectiveness and long-term outcomes

Abstract

Purpose: Chronic kidney disease (CKD) is an important determinant of mortality in patients with congestive heart failure, therefore we sought to determine the impact of CKD on cardiac resynchronization therapy (CRT) benefit and long-term outcomes. Methods: We evaluated 155 patients submitted to CRT between 2006 and 2012, in a single centre. Clinical features, laboratory and echocardiographic findings were analysed at baseline and 6 months after CRT. CKD was defined as a glomerular filtration rate (eGFR) < 60 mL/min/1.73m2, estimated by the Modification of Diet in Renal Disease equation. Six months after CRT, patients were classified as responders to CRT if they showed a decrease in left ventricular end-systolic volume >15%. The mean follow-up time was 41±26 months. The prognostic effect of CKD on long-term outcomes was assessed by Kaplan-Meier survival analysis, rehospitalisation rate due to heart failure and the combined endpoint of all-cause mortality and heart failure readmissions. Results: Patients with CKD (n=55, 35.5%) at the time of device implantation were older (69.0±7.9 vs. 58.4±9.9 years, p<0.01) than patients without CKD, but had no significant differences regarding preimplantation NYHA functional class, ejection fraction or other echocardiographic parameters. During long-term follow-up, CKD patients presented a higher mortality (18.2% vs. 7.0%, p<0.05) and a higher rate of the combined endpoint (49.1% vs. 31%, p<0.05). However, the proportion of echocardiographic responders between patients with and without CKD was similar (53.7% vs. 52.6%). Conclusions: CKD is common in patients undergoing CRT and it is associated with a higher mortality, even though they have similar echocardiographic response. Consequently, CKD should certainly be considered in the decision of implanting a CRT-P or a CRT-D.