Combined Effects of Admission Serum Creatinine Concentration with Age and Gender on the Prognostic Significance of Subjects with Acute ST-Elevation Myocardial Infarction in China

OBJECTIVE: to explore the impact of admission serum creatinine concentration on the in-hospital mortality and its interaction with age and gender in patients with acute ST-segment elevation myocardial infarction (STEMI) in China. METHODS: 1424 acute STEMI patients were enrolled in the study. Anthropometric and laboratory measurements were collected from every patient. A Cox proportional hazards regression model was used to determine the relationships between the admission serum creatinine level (Cr level), age, sex and the in-hospital mortality. A crossover analysis and a stratified analysis were used to determine the combined impact of Cr levels with age and gender. RESULTS: Female (HR 1.687, 95%CI 1.051∼2.708), elevated Cr level (HR 5.922, 95%CI 3.780∼9,279) and old age (1.692, 95%CI 1.402∼2.403) were associated with a high risk of death respectively. After adjusting for other confounders, the renal dysfunction was still independently associated with a higher risk of death (HR 2.48, 95% CI 1.32∼4.63), while female gender (HR 1.19, 95%CI 0.62∼2.29) and old age (HR 1.77, 95%CI 0.92∼3.37) was not. In addition, crossover analysis revealed synergistic effects between elevated Cr level and female gender (SI = 3.01, SIM = 2.10, AP = 0.55). Stratified analysis showed that the impact of renal dysfunction on in-hospital mortality was more pronounced in patients <60 years old (odds ratios 11.10, 95% CI 3.72 to 33.14) compared with patients 60 to 74 years old (odds ratios 5.18, 95% CI 2.48∼10.83) and patients ≥75years old (odds ratios 3.99, 95% CI 1.89 to 8.42). CONCLUSION: Serum Cr concentration on admission was a strong predictor for in-hospital mortality among Chinese acute STEMI patients especially in the young and the female.