Effect of delayed hospitalization on 3-year clinical outcomes according to renal function in patients with non-ST-segment elevation myocardial infarction.

Background: We evaluated the effect of delayed hospitalization (symptom-to-door time [STD] ≥ 24 h) on 3-year clinical outcomes according to renal function in patients with non-ST-segment elevation myocardial infarction (NSTEMI) undergoing new-generation drug-eluting stent (DES) implantation.

Methods: A total of 4513 patients with NSTEMI were classified into chronic kidney disease (CKD) (estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73 m², n = 1118) and non-CKD (eGFR ≥ 60 mL/min/1.73 m², n = 3395) groups. They were further sub-classified into groups with (STD ≥ 24 h) and without (STD < 24 h) delayed hospitalization. The primary outcome was the occurrence of major adverse cardiac and cerebrovascular events (MACCE), defined as all-cause death, recurrent myocardial infarction, any repeat coronary revascularization, and stroke. The secondary outcome was stent thrombosis (ST).

Results: After multivariable-adjusted and propensity score analyses, the primary and secondary clinical outcomes were similar in patients with or without delayed hospitalization in both CKD and non-CKD groups. However, in both the STD < 24 h and STD ≥ 24 h groups, MACCE (p < 0.001 and p < 0.006, respectively) and mortality rates were significantly higher in the CKD group than in the non-CKD group. However, ST rates were similar between the CKD and non-CKD groups and between the STD < 24 h and STD ≥ 24 h groups.

Conclusions: Chronic kidney disease appears to be a much more important determinant of MACCE and mortality rates than STD in patients with NSTEMI.