Impact of admission serum total cholesterol level on in-hospital mortality in patients with acute aortic dissection

OBJECTIVE: To find out the association between serum total cholesterol (TC) on admission and in-hospital mortality in patients with acute aortic dissection (AAD). METHODS: From January 2007 to January 2014, we enrolled 1492 consecutive AAD patients with serum TC measured immediately on admission. Baseline characteristics and in-hospital mortality were compared between the patients with serum TC above and below the median (4.00 mmol/L). Propensity score matching (PSM) was used to account for known confounders in the study. Cox proportional hazard model was performed to calculate the hazard ratio (HR) and 95% confidence interval (CI) for admission serum TC levels. RESULTS: With the use of PSM, 521 matched pairs of patients with AAD were yielded in this analysis due to their similar propensity scores. Patients with admission serum TC < 4.00 mmol/L, as compared with those with admission serum TC ≥ 4.00 mmol/L, had higher in-hospital mortality (11.7% vs. 5.8%; HR, 2.06; 95% CI, 1.33-3.19, P = 0.001). Stratified analysis according to Stanford classification showed that the inverse association between admission serum TC and in-hospital mortality was observed in patients with Type-A AAD (24.0% vs. 11.3%; HR, 2.18; 95% CI, 1.33 - 3.57, P = 0.002) but not in those with Type-B AAD (3.8% vs. 2.2%; HR, 1.71; 95% CI, 0.67 - 4.34, P = 0.261). CONCLUSIONS: Lower serum TC level on admission was strongly associated with higher in-hospital mortality in patients with Type-A AAD.