Prevalence, Associated Risk Factors, and Adverse Cardiovascular Outcomes of Statins Discontinuation: A Systematic Review.

Purpose: Statins are widely prescribed for cardiovascular diseases (CVD) prevention; however, a significant proportion of users discontinue the medication for various reasons. This review aimed to determine the prevalence of statin therapy discontinuation, its associated factors, and adverse cardiovascular outcomes within the first year of discontinuation.

Methods: The PubMed, EMBASE, ScienceDirect, SCOPUS, and Google Scholar databases were systematically searched from their inception to December 2022. Manual searches were also conducted on the bibliographies of relevant articles. Studies were included for qualitative data synthesis and assessed for methodological quality.

Results: Fifty-two studies, predominantly cohort studies (n = 38), involving 4 277 061 participants were included. The prevalence of statin discontinuation within the first year of statin initiation ranged from 0.8% to 70.5%, which was higher for primary prevention indications. Factors frequently associated with an increased likelihood of statin discontinuation included male sex, nonWhite ethnicity, smoking status, and being uninsured. Conversely, discontinuation was less likely in patients with CVD who received secondary prevention statin therapy and in patients with polypharmacy. Furthermore, age showed diverse and inconsistent relationships with statin discontinuation among various age categories. Five studies that reported the cardiovascular risk of statin discontinuation within the first year of initiation showed significantly increased risk of discontinuation, including all-cause mortality (hazard ratio: 1.36-3.65).

Conclusion: Our findings indicate a high prevalence of statin discontinuation and an increased likelihood of adverse cardiovascular outcomes within the first year of discontinuation, despite wide variability across published studies. This review highlights the importance of addressing the modifiable risk factors associated with statin discontinuation, such as smoking and lack of insurance coverage.