Preservation of renal function in response to cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy (CRT) has recently been introduced as a new option for patients with severe heart failure, but its effect on renal function remains unclear.

Methods And Results: Twenty-three patients receiving CRT were studied. Responders were those who showed >0% increase in left ventricular ejection fraction after CRT by echocardiography. Clinical parameters, echocardiographic measurement, renal function, and prescriptions were examined before and 3 months after CRT, and the relationship between the response to CRT and renal function was examined. The responders had a better prognosis than the non-responders (p<0.05). There was a significant difference in the change in the estimated glomerular filtration rate between the responders and non-responders (p<0.05), even in patients with renal dysfunction before CRT (p<0.01). Prescriptions of angiotensin-converting enzyme inhibitors/angiotensin II receptor blockers (ACEI/ARB) were 100% in the CRT responders and 60% in the non-responders (p<0.05). Up-titration of beta-blockers could be significantly achieved in the CRT responders compared with the non-responders (p<0.05).

Conclusions: Preservation of renal function was observed in the responders to CRT, even in patients with renal dysfunction. Prescription of ACEI/ARB and up-titration of beta-blockers increased in the CRT responders. These results may contribute to the beneficial effects of CRT.