Physician Disagreement With Guidelines as a Critical Barrier to Achieving LDL-C Targets in Very High-Risk Patients: An Implementation Science Study

Background: We aimed to investigate the challenges Korean physicians face in assisting their high-risk atherosclerotic cardiovascular disease (ASCVD) patients in achieving guideline-recommended low-density lipoprotein cholesterol (LDL-C) levels. Methods: We performed a prospective, implementation science study including 704 patients at very high risk of ASCVD with baseline LDL-C > 70 mg/dL (1.8 mmol/L) while receiving maximally tolerated statins and/or ezetimibe for secondary prevention between 2020 and 2022. The primary evaluation criteria were the proportions of participants achieving LDL-C < 70 mg/dL at each visit. The secondary evaluation criteria included the proportions of participants in diverse situations associated with guideline adoption. Results: The proportions of participants achieving LDL-C < 70 mg/dL at visits 2 (week 6-16) and 3 (week 18-30) were 56.3% and 58.7%, respectively. Among 307 patients on maximally tolerated statins and 397 patients on maximally tolerated statins and ezetimibe at baseline, physicians did not have an intention to intensify the lipid-lowering treatment regimen of 171 patients (55.7%) and 299 patients (75.3%) at visit 1, respectively. In both groups, physician disagreement with the guidelines was the major reason for not adopting the recommended therapy (70.8% and 46.2%, respectively), followed by patient refusal for reasons other than the cost, medical limitations such as comorbidities, and drug costs. Conclusion: This implementation science study for secondary prevention involving very high-risk ASCVD patients revealed that the proportion of patients achieving LDL-C < 70 mg/dL via lipid-lowering therapy was less than 60%. The main reason for not adopting the recommended LDL-C-lowering therapy was physician disagreement with the guidelines.