Reduction in total recurrent cardiovascular events in acute coronary syndrome patients with low-density lipoprotein cholesterol goal <70 mg/dL: a real-life cohort in a developing country

BACKGROUND: For investigations into cardiovascular disease, the first problematic event (ie, nonfatal acute coronary syndrome (ACS), nonfatal stroke, or all-cause mortality) generally was considered as the primary end point; however, ACS patients often experience subsequent events, which are rarely considered. This study reports an investigation into whether achieving a low-density lipoprotein cholesterol (LDL-C) goal of <70 mg/dL (1.8 mmol/L) is associated with a reduction in total recurrent cardiovascular events in a cohort of ACS patients hospitalized in northern Thailand. METHODS: The medical charts and the electronic hospital database of ACS patients treated with statins at a tertiary hospital in Thailand between 2009 and 2012 were reviewed. Patients were checked for their LDL-C goal attainment, and then were followed for subsequent events until the last follow-up date, or to December 31, 2012. The Wei-Lin-Weissfeld method was used for multiple time-to-events data to investigate the association between achieving an LDL-C goal of <70 mg/dL and total recurrent cardiovascular events. RESULTS: Of 405 eligible patients, 110 patients attained an LDL-C goal of <70 mg/dL. During a median follow-up of 1.94 years, the majority of patients (88.6%) had no subsequent cardiovascular events, while 46 patients experienced at least one recurrent cardiovascular event: 36 with one event, six with two events, two with three events, one with four events, and one with seven events. Compared to patients with an LDL-C ≥100 mg/dL, patients achieving an LDL-C of <70 mg/dL were significantly less likely to experience total cardiovascular events (adjusted hazard ratio =0.29; 95% confidence interval =0.09-0.87; P-value =0.028); the result was similar to patients with an LDL-C of 70-100 mg/dL, but it was not significant (adjusted hazard ratio =0.53; 95% confidence interval =0.23-1.26; P-value =0.154). CONCLUSION: ACS patients receiving statins who attained an LDL-C <70 mg/dL experienced a reduction in total recurrent cardiovascular events compared to those with LDL-C ≥100 mg/dL.