Coronary artery disease
Low-Density Lipoprotein Cholesterol Level in Patients With Acute Myocardial Infarction Having Percutaneous Coronary Intervention (the Cholesterol Paradox)

https://doi.org/10.1016/j.amjcard.2010.06.009Get rights and content

The relation between low-density lipoprotein (LDL) cholesterol levels and clinical outcomes after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) has not been described. A total of 9,571 eligible patients (mean age 62.6 ± 12.5 years, 6,967 men) who underwent PCI with a final diagnosis of AMI from the Korea Acute Myocardial Infarction Registry (KAMIR) were divided into 5 groups according to LDL cholesterol level: <70, 70 to 99, 100 to 129, 130 to 159, and ≥160 mg/dl. Clinical outcomes in hospital and 1 and 12 months after PCI in patients with AMI were examined. Age and co-morbidities decreased as LDL cholesterol increased. Patients with higher LDL cholesterol levels had favorable hemodynamic status and laboratory findings. Lifesaving medications, including lipid-lowering drugs, were underused in patients with lower LDL cholesterol levels. Clinical outcomes in hospital and 1 and 12 months after PCI showed better results as LDL cholesterol increased, except for patients with LDL cholesterol levels ≥160 mg/dl. In a Cox proportional-hazards model, LDL cholesterol level was not an independent predictor of mortality at 12 months, after adjusting for clinical characteristics including demographics and biologic data. In conclusion, the cholesterol paradox in patients with AMI is related to confounding by baseline characteristics associated with survival. More intensive treatment including lipid-lowering therapy for AMI in patients with lower LDL cholesterol level may result in better clinical outcomes.

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Methods

KAMIR is a prospective, multicenter, observational data collection registry investigating the risk factors of mortality in AMI and establishing the universal management for the prevention of AMI, with the support of Korean Circulation Society since November 2005. The database is comprehensive and includes age, gender, body mass index (BMI), vital signs, Killip class, symptom onset time, door-to-needle time, door-to-balloon time, each risk factor, past regular medications, co-morbidities,

Results

The mean LDL cholesterol level in all patients was 118 ± 43 mg/dl. The mean LDL cholesterol levels were 116 ± 40 mg/dl in men and 123 ± 49 mg/dl in women (p <0.001). LDL cholesterol levels were correlated weakly with age and decreased with increasing age. The correlation between LDL cholesterol level and BMI was positive but weak (Figure 1).

Baseline clinical characteristics and laboratory findings of the patients' groups are listed in Table 1. A history of hypertension, diabetes, previous

Discussion

The present study demonstrated that higher LDL cholesterol levels, except for patients with LDL cholesterol levels ≥160 mg/dl, were related to better clinical outcomes after PCI in patients with AMI. However, this cholesterol paradox may be due to several confounders. Of the independent predictive factors of 12-month mortality after PCI in patients with AMI, age, systolic blood pressure, Killip class, the LVEF, creatinine clearance, N-terminal–pro–B-type natriuretic peptide level, and the use

Acknowledgment

The KAMIR investigators were Myung Ho Jeong, MD, Youngkeun Ahn, MD, Shung Chull Chae, MD, Jong Hyun Kim, MD, Seung Ho Hur, MD, Young Jo Kim, MD, In Whan Seong, MD, Dong Hoon Choi, MD, Jei Keon Chae, MD, Taek Jong Hong, MD, Jae Young Rhew, MD, Doo Il Kim, MD, In Ho Chae, MD, Jung Han Yoon, MD, Bon Kwon Koo, MD, Byung Ok Kim, MD, Myoung Yong Lee, MD, Kee Sik Kim, MD, Jin Yong Hwang, MD, Myeong Chan Cho, MD, Seok Kyu Oh, MD, Nae Hee Lee, MD, Kyoung Tae Jeong, MD, Seung Jea Tahk, MD, Jang Ho Bae,

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This study was performed with the support of the Korean Circulation Society, Seoul, Korea, in commemoration of its 50th anniversary.

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