Statins are used for primary prevention in adults aged 40 to 75 years who are at high risk (that is, greater than 7.5% risk of a major adverse cardiac event or MACE) over the next 10 years).
Guidance on the use of statins as a means of reducing this risk recommends that any decisions are made jointly by patients and clinicians, especially given the wide range of cardiovascular risk factors, comorbidity burden and life expectancy of patients within this age range. While the benefits of statin therapy are well established, what remains unclear is the time-frame over which these benefits occur. In other words, how long is the “time to benefit” (TTB) from statins.
In an analysis, researchers from the Division of Geriatrics and Gerontology, University of California, US, conducted a meta-analysis of the major randomised clinical trials to determine the TTB, which served as the primary outcome and which they defined as the time from starting a statin to the first MACE. The team only included trials which had more than 1000 participants, aged at least 55 years and older. Given that the focus was primary prevention, researchers also limited the search to those trials in which less than 15% of participants had pre-existing cardiovascular disease.
A search of all the major databases, identified 8 randomised trials including 65,383 patients (66.3% male) and with less than 10% of participants having existing cardiovascular disease. The analysis showed how the benefit of statin therapy increased with the duration of the study so that, for example, after 1 year, 0.3 MACEs were prevented for every 100 people treated with statins and this increased to 2.5 MACEs after 5 years. They calculated that 2.5 years were required to prevent 1 MACE for every 100 patients given statins. Thus statin treatment was only likely to benefit patients aged 50 to 75 years where they had a life expectancy of at least 2.5 years. Interestingly, only one statin trial found that therapy reduced overall mortality.
The authors concluded that their results reinforce the importance of individualised statin treatment-related decision making.
Yourman LC et al. Evaluation of time to benefit of statins for primary prevention of cardiovascular events in adults aged 50 to 75 years. A Meta-analysis. JAMA Intern Med 2020 doi:10.1001/jamainternmed.2020.6084