Low-density Lipoprotein Cholesterol Level on Admission and After One Year with Clinical Outcomes in Patients Admitted with Acute Coronary Syndrome Undergoing Percutaneous Coronary Intervention

Introduction: Percutaneous coronary intervention (PCI) is the established treatment for acute coronary syndromes (ACS). Despite optimal procedural outcomes with advanced hardware, recurrent coronary events within 1-year are known to occur. In-patients with documented ACS, the American College of Cardiology/American Heart Association recommends use of high intensity statins (which lowers low-density lipoprotein cholesterol (LDL-C) by ≥50%), i.e., 40–80 mg for atorvastatin though the European guidelines have recommended a LDL-C level of 1.4 mmol/l or below as a core preventative measure for future events. Objective: The aim of the study is to find proportion of patients with European guideline recommended target of LDL-C <1.4 mmol/L during the first presentation of ACS, and after 1 year, and to correlate with 1-year clinical outcomes in patients undergoing PCI. Methods: This is a retrospective observational study at a tertiary care referral hospital of ACS patients who underwent PCI from January 1, 2019, to December 31, 2019. A total of 371 patients were included in the study who had a baseline and 1-year lipid profile data. Patients were divided into two groups, LDL-C ≤1.4 mmol/L (Group 1) and more than 1.4 mmol/L (Group 2) and compared for major adverse cardiovascular events (MACE). Results: At presentation, 354 (95%) patients presented with LDL-C level above 1.4 mmol/L. Mean LDL-C level at presentation and at 1-year was high at 3.05 ± 1.11 and 2.36 ± 1.06 mmol/L, respectively. Majority of the patients were on atorvastatin 40 mg at discharge (77%). At 1 year, only 15% had LDL-C level below 1.4 mmol/L and 79% were still on 40 mg of atorvastatin. Overall, 51% of the cohorts were asymptomatic and 32% presented with MACE. Majority of MACE occurred in Group 2 80% of total MACE compared to 20% in Group 1. Unadjusted odds ratios for myocardial infarction, cardiac death, and target vessel revascularization by PCI in Group 2 were not significant. However, they were high for cerebrovascular accident (CVA) (4.4) and coronary artery bypass surgery (1.9). Seventy-two percent of patients had 50% reduction in their LDL-C from baseline but not reaching a goal of <1.4 mmol/L. However, there was statistically significant increase in CVA and cardiac death in patients with no 50% reduction ( P < 0.05). Conclusions: In a tertiary hospital large-volume ACS-PCI center, more than two-thirds of patients had their mean LDL-C level at presentation and 1-year beyond the recommended target level of <1.4 mmol/L, with one-third of patients developing 1-year MACE. A strategy of only taking a high-intensity statin was not adequate in reaching the LDL-C goal of <1.4 mmol/L though two-thirds of patient achieved 50% reduction in their LDL-C. There is an urgent need to educate physicians in the region to follow the recommended target LDL-C of 1.4 mmol/L and escalate the statin dose. In addition, there is a need to make availability of add-on anti-lipid drugs to attain this target and prevent MACE.