The prognostic value of very low admission LDL-cholesterol levels in ST-segment elevation myocardial infarction compared in statin-pretreated and statin-naive patients undergoing primary percutaneous coronary intervention

Background: Some recent trials reported that, low admission low-density lipoprotein-cholesterol (LDL-C) levels were associated with increased mortality in patients with acute coronary syndromes. We aimed to compare the effect of very low admission LDL-C levels on prognosis in statin-pretreated and statin-naive patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing primary angioplasty. Methods: The study population consisted of 1808 patients with acute STEMIs who underwent primary angioplasty. The patients were categorized into four groups as: statin-pretreated/LDL-C < 70 mg/dl (n = 128), statin-pretreated/LDL-C ≥ 70 mg/dl (n = 290), statin-naive/LDL-C < 70 mg/dl (n = 146), statin-naive/LDL-C ≥ 70 mg/dl (n = 1244). The median follow-up was 40 months. Results: The incidences of diabetes mellitus, hypertension, renal insufficiency, anemia, cardiogenic shock on presentation and the mean age were significantly higher in the statin-naive/LDL-C < 70 mg/dl group. In-hospital (2.3% vs 2.4% vs 12.3% vs 3.9%, respectively p < 0.001) and long-term mortalities (6.3% vs 7.3% vs 25.9% vs 11.3% respectively, p < 0.001) were significantly lower in the "statin-pretreated/LDL-C < 70" group. Statin pretreatment was independently predicting lower long-term mortality irrespective of LDL-C level [for the subgroup with LDL-C < 70 mg/dl, Hazard Ratio (HR) 0.24, 95% CI 0.10-0.59, p = 0.013; for the subgroup with LDL-C ≥ 70 mg/dl, HR 0.31, 95% CI 0.14-0.83, p = 0.022]. LDL-C levels on admission had no independent predictive role on long-term mortality. Conclusions: Statin induced low LDL-C levels on admission are associated with better short- and long-term outcomes in patients with STEMI and independently predict lower long-term mortality. However, spontaneously low admission LDL-C levels were associated with increased short- and long-term mortalities.