Outcomes after percutaneous coronary intervention for chronic total occlusion according to baseline renal function.

Background: Chronic kidney disease (CKD) adversely affects outcomes in patients with coronary artery disease. Data on the impact of renal impairment on prognosis of patients undergoing percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) are scarce.
Methods: A total of 2002 patients undergoing CTO PCI were stratified according to baseline renal function (group 1: estimated glomerular filtration rate [eGFR] ≥ 90 ml/min/1.73 m ² , group 2: 60 to 89 ml/min/1.73 m ² , group 3: 30 to 59 ml/min/1.73 m ² , and group 4: <30 ml/min/1.73 m ² ). The primary outcome measure was all-cause mortality at a median follow-up of 2.6 (interquartile range 1.1-3.1) years.
Results: All-cause mortality increased with decreasing renal function (group 1: 5.0%, group 2: 9.5%, group 3: 26.4%, and group 4: 38.7%, log rank p < 0.001). Continuous eGFR values were significantly related with all-cause mortality (adjusted HR 0.98, 95% CI 0.98-0.99, p < 0.001). Procedural failure was associated with all-cause mortality both in patients with an eGFR < 60 ml/min/1.73 m ² (42.6 vs. 23.7%, adjusted HR 1.59, 95% CI 1.08-2.32, p = 0.02) and in those with an eGFR ≥ 60 ml/min/1.73 m ² (14.6 vs. 6.5%, adjusted HR 1.73, 95% CI 1.15-2.60, p = 0.009, interaction p = 0.47).
Conclusions: Although renal impairment is associated with all-cause mortality in patients undergoing CTO PCI, successful CTO recanalization is related to improved survival irrespective of renal function.