High cystatin C levels predict long‐term mortality in patients with ST‐segment elevation myocardial infarction undergoing late percutaneous coronary intervention: A retrospective study

OBJECTIVES: Late percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI), defined as time of PCI > 7 days from symptom onset, is a common practice with clinical benefits. This study aimed to evaluate the predictive value of admission cystatin C (cys C) level on long-term mortality in STEMI patients receiving late PCI. METHODS: Medical records of STEMI patients who were hospitalized between 2009 and 2011 from eight PCI-capable hospitals in Northwest China were retrospectively analyzed. Cys C level ≥ 1.105 mg/L was considered as the best predictor of long-term mortality based on the receiver-operating characteristic analysis. Patients were followed up by phone or face-to-face interviews, and the long-term mortality was obtained by reviewing medical records. RESULTS: The final analysis included 716 STEMI patients who received late PCI and had available cys C levels prior to PCI, and 524 were assigned into the high cys C group and 192 the low cys C group. Patients were followed up for an average length of 40.37 months. Compared with the low cys C group, the high cys C group had a higher long-term all-cause mortality (10.4% vs 2.9%, P < 0.001) and a higher cardiac mortality (6.8% vs 2.1%, P = 0.004). Multivariate Cox regression analysis showed that high cys C level was an independent predictor for both long-term all-cause mortality and cardiac mortality. CONCLUSIONS: High cys C level at admission is an independent predictor of long-term mortality in STEMI patients undergoing late PCI.