The Association Between Time of Lipid-Lowering Therapy Initiation and Acute Clinical Presentation Among Patients Admitted With Coronary Artery Disease, and Its Effect on Future Cardiovascular Events: An Australian Observational Study

Background Lipid-lowering therapy (LLT) is established as a key element in management of patients with coronary artery disease. However, the effect of time of initiation of LLT on outcomes is unclear. Method The study compared outcomes of 5,433 patients from Advara HeartCare's Percutaneous Coronary Intervention (PCI) Registry on the basis of timing of LLT initiation classified as pre- or post-PCI admission. The prevalence of acute coronary syndrome (ACS) as the indication for PCI was compared in groups. In patients who underwent PCI for ACS, the incidence of short- (<30 days) and long-term (>30 days after admission) clinical events (composite of myocardial infarction, cerebrovascular disease, coronary revascularisation, all-cause readmission, and mortality) and first non-fatal cardiovascular events were compared in groups. Results At the time of hospitalisation for PCI, 3,982 (73.7%) were on LLT (PRE-LLT), and 1,418 (26.2%) initiated LLT after admission (POST-LLT). Patients on PRE-LLT were significantly less likely to experience ACS before admission for PCI than were those commencing LLT after discharge (PRE-LLT 32.3% vs POST-LLT 56.9%; p<0.001), even after matching for baseline risk factors. Among these patients with ACS, patients on PRELLT were older than those on POST-LLT (mean 69.5 +/- 9.5 vs 65.0 +/- 10.0 years; p<0.001), and had a higher prevalence of cardiovascular risk factors including diabetes (31.5% vs 9.6%; p<0.001), hypertension (79.7% vs 51.7%; p<0.001), and renal failure (7.6% vs 2.0%; p<0.001). No difference was observed between groups in the risk of short- or long-term (median 2.0 years; interquartile range 1.0-3.0) post-PCI cardiovascular (hazard ratio [HR] 1.08; 0.83-1.40; p=0.55) or overall clinical events (HR 1.11; 0.93-1.32; p=0.26). Conclusions In patients with coronary artery disease, the risk of ACS is reduced by early initiation of LLT before revascularisation is required. Long-term outcomes of patients at high risk prescribed LLT before admission for ACS PCI may not differ from those of patients at lower risk commencing LLT after PCI for ACS.