The study included 696 patients who underwent ICD placement for clinical reasons (59 % primary, 41 % secondary prevention) at the University of Alabama at Birmingham between January 2002 and September 2007. CKD was defined as an estimated glomerular filtration rate < 60 ml/min/1.73 m2 but not on dialysis. Outcomes of interest included overall mortality and first appropriate ICD therapy (shocks or anti-tachycardia pacing).
After a follow-up of 50 ¡À 24 months, 213 patients died (31 % ) and 111 (16 % ) received appropriate ICD therapy. Patients with CKD had higher mortality than patients with no CKD in the primary (43 % vs. 15 % , p < 0.001) and secondary prevention (37 % vs. 23 % , p = 0.003) groups. Patients with CKD were at higher risk of receiving an appropriate ICD therapy than patients without CKD in the primary (p < 0.001) but not secondary prevention (p = 0.9) cohort. After adjusting for age, gender and multiple risk factors, CKD was independently associated with all-cause mortality and ICD therapy in the primary prevention group (HR 2.08 [1.34-3.23] and 3.53 [1.75-7.10], p = 0.001 and < 0.0001, respectively) but not in the secondary prevention group (HR 1.27 [0.81-2.00], and 0.63 [0.35-1.13], p = 0.3 and 0.2, respectively).
CKD is independently associated with increased mortality and appropriate ICD therapy in patients undergoing ICD implantation for primary but not secondary prevention.