The aim of the study was to examine the possible influence of minor deterioration of the renal function after stent implantation not fulfilling the criteria for acute kidney injury on long-term outcomes after stent thrombosis (ST).
Decreased renal function (DRF) is associated with an increased risk for worse outcome after percutaneous coronary intervention. There is no data if the deterioration of renal function after stent implantation influences the prognosis after ST. If so patients with a higher risk for worse outcome after ST could be identified already at the time of stent implantation.
Data from 4824 consecutive patients treated with percutaneous coronary intervention in our center was recorded from March 2004 to April 2010. We excluded patients with acute kidney injury at stent implantation and 86 of them with ST without acute kidney injury at stent implantation were involved in the study. They were prospectively followed until December 2012 for 50.2 ± 28.1 months. Only patients with definite ST were included in the study. The Academic Research Consortium definition of ST was used. Data on death, myocardial infarction, and repeated percutaneous or operative revascularization after ST were ascertained from the hospital database, by phone or with clinical examinations. The outcomes after definite ST were compared in patients with and without deterioration of renal function after stent implantation (DRFafterSI).
During the observational period patients with DRFafterSI had a higher mortality rate after ST than patients without DRFafterSI (35.1 vs. 10.3 %; p <0.019). The incidence of major adverse cardiac events (major adverse coronary event (MACE)—death, myocardial infarction, repeated revascularization) rate after ST was similar in both groups (66.1 % with DRFafterSI vs. 55.2 % without DRFafterSI). The prevalence of myocardial infarction was also similar in both groups (31.6 vs. 34.5 %) as was the revascularizations rate (43.9 vs. 48.3 %). Death was predicted by DRFafterSI (adjusted hazard ratio (HR) 3.96; 95 % confidence interval (CI) 1.11 to 14.10; p <0.034) and age > 75 years (adjusted HR 2.85: 95 % CI 1.12–7.30; p = 0.029). We could not find any predictor for MACE.
Even more subtle DRFafterSI (not fulfilling the criteria for acute kidney injury) at stent implantation were associated with higher long-term mortality after ST. Especially at risk were patients older than 75 years at stent implantation. DRFafterSI and age more than 75 years pointed out the group of patients with a high risk for death after ST already at the time of stent implantation. The best treatment option for preventing ST in these patients is still to be determined. Until then, we must pay a special attention to proper patients’ preparation and hydration to avoid DRFafterSI.