Low-density lipoprotein cholesterol of less than 70 mg/dL is associated with fewer cardiovascular events in acute coronary syndrome patients: a real-life cohort in Thailand

Background: Elevated low-density lipoprotein cholesterol (LDL-C) is associated with an increased risk of cardiovascular disease or mortality; however, the LDL-C goal for therapy in acute coronary syndrome (ACS) patients is controversial and varies among guidelines. This study aimed to assess the effect of reaching an LDL-C goal of <70 mg/dL (<1.8 mmol/L) on first composite cardiovascular outcomes in routine clinical practice in Thailand. Methods: A retrospective cohort study was conducted using medical charts and the electronic hospital database of patients diagnosed with ACS and treated with statins at a tertiary care hospital in Thailand between 2009 and 2012. After admission, patients were followed from the date of LDL-C goal assessment until the first event of composite cardiovascular outcomes (nonfatal ACS, nonfatal stroke, or all-cause death). Cox proportional hazard models adjusted for potential confounders were used. Results: Of 405 patients, mean age was 65 years (60% males). Twenty-seven percent of the patients attained an LDL-C goal of<70 mg/dL, 38% had LDL-C between 70 and 99 mg/dL, and 35% had LDL-C ≥100 mg/dL. Forty-six patients experienced a composite cardiovascular outcome. Compared with patients with an LDL-C ≥100 mg/dL, patients achieving an LDL-C of <70 mg/dL were associated with a reduced composite cardiovascular outcome (adjusted hazard ratio [HR]=0.42; 95% confidence interval [CI]=0.18-0.95; P-value=0.037), but patients with an LDL-C between 70 and 99 mg/dL had a lower composite cardiovascular outcome, which was not statistically significant (adjusted HR=0.73; 95% CI=0.37-1.42; P-value=0.354). Conclusion: ACS patients who received statins and achieved an LDL-C of <70 mg/dL had significantly fewer composite cardiovascular outcomes, confirming "the lower the better" and the benefit of treating to LDL-C target in ACS patient management.