Treatment patterns and adherence to lipid-lowering drugs during 8 years of follow-up after a cardiovascular event

Abstract

Abstract Introduction In previous research using nationwide prescription data we demonstrated that a considerable proportion of statin users in Norway had treatment gaps or discontinuation in treatment, with 20% of patients having gaps exceeding 180 days. Yet, evidence for treatment practice and long-term adherence to lipid lowering drugs among patients with atherosclerotic cardiovascular disease is limited. Purpose To investigate long-term treatment patterns and adherence to lipid lowering drugs following hospitalization for an acute cardiovascular event. Secondary, to investigate the association between patient characteristics and adherence. Methods Consecutive patients admitted to two hospitals in Norway with acute myocardial infarction or angina undergoing revascularization from 2011-2014 (N=1094) were included in this study. Data on clinical and psychosocial factors were linked to prescription registry data from 2010 to the date of death or end-of follow-up (2020). We evaluated treatment adherence from time of hospital admission to end of follow-up by estimating proportion of days covered (PDC) and gaps in statin treatment. Risk of gaps in statin treatment of >180 days were evaluated across different patient subgroups. Treatment practice after hospital discharge was assessed by the proportion of patients with atorvastatin 40/80 mg or rosuvastatin 20/40 mg, and the proportion of patients with a subsequent ezetimibe prescription. Results Median age was 63 years (SD 9.6) at time of hospital admission. 96% of the patients were discharged with a statin at the index event. During a median of 8 years (SD 2.5) of follow-up, 16% had a gap in their statin treatment exceeding 180 days, and 22% had a PDC < 0.8. LDL-cholesterol target achievement at follow-up was poor and psychosocial distress was prevalent (Table 1). The proportion of patients with gaps ≥180 days was quite similar in all patient subgroups, however somewhat more prevalent among patients who reported statin side-effects (Figure 1). Less than two out of three patients were prescribed high intensity statin therapy during follow-up, while 25% received additional treatment with ezetimibe (Figure 1). Mean number of milligrams redeemed during follow-up was 43 for atorvastatin, 36 for simvastatin and 18 for rosuvastatin. Conclusion In this study of patients hospitalized for an atherosclerotic cardiovascular event, long-term follow-up over 8 years showed that a considerable proportion of patients have poor statin adherence, with gaps in treatment exceeding 180 days. Furthermore, many patients are treated with suboptimal statin therapy, and only 1 out of 4 patients were prescribed ezetimibe. There is a considerable potential for improving long-term adherence and optimizing lipid lowering therapy in secondary prevention.Patient characteristics (N=1094)Proportion of patients with gap>180 days