Impact of renal dysfunction on appropriate therapy in implantable cardioverter defibrillator patients with non-ischaemic dilated cardiomyopathy

Abstract

To examine the effect of renal dysfunction on the occurrence of life-threatening ventricular arrhythmia in patients with non-ischaemic dilated cardiomyopathy and implantable cardioverter defibrillator (ICD). Subjects were 274 consecutive patients with non-ischaemic dilated cardiomyopathy who received ICD implantation. Estimated glomerular filtration rate (eGFR) was calculated using the modification of diet in renal disease formula. Renal dysfunction was defined as eGFR <60 mL/min/1.73 m(2). Differences in survival, appropriate ICD therapy and electrical storm in patients with and without renal dysfunction were compared. The effect of worsening renal function (decrease of eGFR of at least 15 mL/min/1.73 m(2) within 1 year) on appropriate ICD therapy was also evaluated. There was a higher incidence of appropriate ICD therapy in patients with eGFR <60 mL/min/1.73 m(2) than in those with eGFR >or=60 mL/min/1.73 m(2) (P = 0.0001). Patients with eGFR <60 mL/min/1.73 m(2) also showed a significantly higher rate of electrical storm (P = 0.003). Renal dysfunction with eGFR <60 mL/min/1.73 m(2) was an independent predictor of appropriate ICD therapy (HR 1.85, 95% CI 1.24-2.77, P = 0.003). Patients with worsening renal function within 1 year after implantation were at increased risk for appropriate ICD therapy (HR 2.50, 95% CI 1.39-4.52, P = 0.002). Our results suggested that renal dysfunction is an independent risk factor for occurrence of life-threatening arrhythmia even in high-risk patients with non-ischaemic dilated cardiomyopathy.