Paradoxical impact of decreased low-density lipoprotein cholesterol level at baseline on the long-term prognosis in patients with acute coronary syndrome

Takuya Nakahashi, Hayato Tada, Kenji Sakata, Yohei Yakuta, Yoshihiro Tanaka, Akihiro Nomura, Tadatsugu Gamou, Hidenobu Terai, Yuki Horita, Masatoshi Ikeda, Masanobu Namura, Masayuki Takamura, Kenshi Hayashi, Masakazu Yamagishi, Masa-aki Kawashiri

Although statin therapy is beneficial in the setting of acute coronary syndrome (ACS), a substantial proportion of patients with ACS still do not receive the guideline-recommended lipid management in contemporary practice. We hypothesize that the low-density lipoprotein cholesterol (LDL-C) level at the time of admission might affect patient management and the subsequent outcome. Nine-hundred and forty-two consecutive patients with ACS who underwent percutaneous coronary intervention were analyzed retrospectively. The study patients were first divided into two groups based on the LDL-C level on admission: group A (n = 267), with LDL-C < 100 mg/dL; and group B (n = 675), with LDL-C ≥ 100 mg/dL. Each group was then further divided into those who were prescribed statins or not at the time of discharge from the hospital. The primary endpoint was all-cause death. In addition, we analyzed the serial changes of LDL-C within 1 year. Patients in group A were significantly older and more likely to have multiple comorbidities compared with group B. The proportion of patients who were prescribed statin at discharge was significantly smaller in group A compared with group B (57.7 vs. 77.3%, p < 0.001). During the median 4-year follow-up, there were 122 incidents of all-cause death. Multivariate Cox proportional hazard analysis revealed that LDL-C < 100 mg/dL on admission [hazard ratio (HR), 1.61; 95% confidence interval (CI), 1.09-2.39; p < 0.05] and prescription of statins at discharge (HR, 0.52; 95% CI, 0.36-0.76; p < 0.001) were associated significantly with all-cause death. Under these conditions, increasing LDL-C levels were documented during follow-up in those patients in group A when no statins were prescribed at discharge (79 ± 15-96 ± 29 mg/dL, p < 0.001), whereas these remained unchanged when statins were prescribed at discharge (79 ± 15-77 ± 22 mg/dL, p = 0.30). These results demonstrate that decreased LDL-C on admission in ACS led to less prescription for statins, which could result in increased death, probably due to underestimation of the baseline LDL-C.