Patterns of Statin Use in a Real-World Population of Patients at High Cardiovascular Risk

BACKGROUND: Widespread use of statins has improved hypercholesterolemia management, yet a significant proportion of patients remain at risk for cardiovascular (CV) events. Analyses of treatment patterns reveal inadequate intensity and duration of statin therapy among patients with hypercholesterolemia, and little is known about real-world statin use, specifically in subgroups of patients at high risk for CV events. OBJECTIVE: To examine patterns of statin use and outcomes among patients with high-risk features who newly initiated statin monotherapy. METHODS: Adult patients (aged > 18 years) at high CV risk who received > 1 prescription for statin monotherapy and who had not received lipid-modifying therapy during the previous 12 months were identified from the Truven MarketScan Commercial and Medicare Supplemental databases (from January 2007 to June 2013). Patients with atherosclerotic cardiovascular disease (ASCVD) or diabetes were hierarchically classified into 5 mutually exclusive CV risk categories (listed here in order from highest to lowest risk): (1) recent CV event (subcategorized by hospitalization for acute coronary syndrome [ACS] or other non-ACS CV event within 90 days of index); (2) coronary heart disease (CHD); (3) history of ischemic stroke; (4) peripheral artery disease (PAD); and (5) diabetes. Outcomes of interest included changes in therapy, proportion of days covered (PDC), time to discontinuation, and proportion of patients with ASCVD-related inpatient visit during the follow-up period. Statin therapy was subdivided into high-intensity treatment (atorvastatin 40 mg or 80 mg, rosuvastatin 20 mg or 40 mg, or simvastatin 80 mg) or moderate- to low-intensity treatment (all other statins and statin dosing regimens). Follow-up data were obtained from the index date (statin initiation) until the end of continuous enrollment. RESULTS: A total of 541,221 patients were included in the analysis. The majority of patients were stratified in the diabetes cohort (61.1%), followed in frequency by recent ACS event (15.8%), recent non-ACS CV event (9.9%), PAD (4.7%), CHD (4.4%), and history of ischemic stroke (4.1%). Only 15.0% of the population initiated therapy with a high-intensity statin, and 22.5% of these high-intensity statin initiators switched to a moderate- to low-intensity regimen during the follow-up period. Median time to statin discontinuation was approximately 15 months. Duration of treatment was longer among those who were treated with a high-intensity versus a moderate- to low-intensity statin regimen (21 and 15 months, respectively). The PDC was highest in the recent ACS hospitalization cohort (66.4%) and lowest in the diabetes cohort (55.5%). The PDC was significantly greater among patients who initiated treatment with a high-intensity statin regimen than with a moderate- to low-intensity statin regimen (62.1% vs. 57.5%, respectively; P< 0.001). At 1 year, Kaplan-Meier estimates of the cumulative rates for ASCVD-related hospitalizations ranged from 3.5% (diabetes) to 21.8% (recent ACS hospitalization). CONCLUSIONS: Patients at high risk for CV events are suboptimally dosed with statins, have high rates of discontinuation, and have low rates of adherence. Despite the use of statin therapy, ASCVD-related inpatient visit rates were high, particularly among those patients at highest risk because of a recent ACS hospitalization. Future interventions are required to ensure that high-risk patients are effectively managed to reduce subsequent morbidity and mortality.