Primary prevention with statins only in elderly T2DM patients aged <85 years

Statins for primary prevention of cardiovascular events and mortality in old and very old adults with and without type 2 diabetes: retrospective cohort study

Literature - Ramos R, Comas-Cufí M,Martí-Lluch R et al. - BMJ 2018;362:k3359

Introduction and methods

CVD incidence and mortality rates are almost three times higher in individuals ≥75 years, compared to younger people [1]. Current guidelines on CV prevention recommend statin treatment in almost all patients aged ≥75 years, based on 10-years risk estimation, as CVD incidence is highly dependent on age [2-5]. However, recent reports showed no benefit of pravastatin in primary prevention in adults aged ≥75 years [6]. Moreover, the benefit of statins in primary prevention of CVD in older people with type 2 diabetes (T2DM) has not been sufficiently evaluated [7]. Therefore, this study aimed to assess whether use of statins was associated with reduced incidence of atherosclerotic CVD (ASCVD) and mortality in older individuals without CVD, by T2DM and age.

This retrospective cohort study (2006-2015) using data from Spanish Information System for the Development of Research in Primary Care (SIDIAP) included all individuals aged ≥75 years without a history of CVD, who had at least one visit recorded in the electronic medical records during the 1.5 years before the index date (n=46,864). Eligible subjects were followed for a median of 7.7 years. Exposure of patients to statins was stratified according to cholesterol reduction capacity of these drugs: low (≤30%), moderate (31-40%), high (41-50%), and very high (>50%). Liver toxicity and myopathy that occurred within 12 months of treatment initiation and new diagnosis of T2DM, cancer and hemorrhagic stroke after one year were considered as adverse effects of statin use.

Primary outcomes were total mortality and ASCVD, a composite of CHD (fatal and on-fatal angina, fatal and non-fatal myocardial infarction or cardiac revascularization), and stroke (fatal and non-fatal ischemic stroke). Secondary outcomes were CHD and ischemic stroke.

Main results

  • In patients without T2DM aged 75-84 years, the hazard ratios for statin use were 0.94 (95%CI: 0.86-1.04) for ASCVD and 0.98 (95%CI: 0.91-1.05) for all-cause mortality.
  • Similar results were observed in patients without T2DM aged ≥85 years: HR: 0.93 (95%CI: 0.82-1.06) and HR:0.97 (95%CI: 0.90-1.05), respectively.
  • In T2DM patients aged 75-84 years, the hazard ratios for statin use were 0.76 (95%CI: 0.65-0.89) for ASCVD and 0.84 (95%CI: 0.75-0.94) for all-cause mortality; one-year NNT was 164 for ASCVD and 306 for all-cause mortality.
  • In T2DM patients aged ≥85 years, the hazard ratios for ASCVD and all-cause mortality were HR: 0.82 (95%CI: 0.53-1.26) and HR: 1.05 (95%CI: 0.86-1.28), respectively.
  • In the estimation for hazard ratios for each year of age, the hazard ratios showed a statistically significant and clinically relevant reduction in ASCVD in T2DM patients treated with statins. This reduction lost statistical significance at age 85 years. Reduction in all-cause mortality lost statistical significance at age 82 years or more. The reduction in incidence of ASCVD and in all-cause mortality disappeared in nonagenarians.
  • No significant increase in adverse events due to statins was observed.

Conclusion

The effect of statin therapy in primary prevention in older subjects varied depending on the presence of T2DM. There was no association between statins and reduction in ASCVD or all-cause mortality in participants aged ≥75 years without CVD and T2DM. In contrast, statins were significantly related to a reduction in the incidence of ASCVD and in all-cause mortality in T2DM participants. This effect was substantially reduced after the age of 85 years and disappeared in nonagenarians. Altogether, these results suggest statin treatment in patients with T2DM aged <85 years.

Editorial comment

In their editorial comment [8], Ryan et al. discuss limitations of the study by Ramos et al., including a small number of patients taking high intensity statins, which may underestimate the risk of myopathy, and the lack of information about adverse effects on cognition. They emphasize that the limited protective effects of statins found in this study should be further studied in randomized trials and the effect of statins on CVD death, which was not recorded in this study, should be further investigated as well. The authors conclude: ‘A patient preference for reduction in myocardial infarction or stroke, however, might help to tilt the balance in favor of statin prescription, but the absolute risk reduction and number needed to treat to prevent a CVD event in older patients remains uncertain.’

References

1. Marrugat J, Sala J, Manresa JM, et al, REGICOR Investigators. Acute myocardial infarction population incidence and in-hospital management factors associated to 28-day case-fatality in the 65 year and older. Eur J Epidemiol 2004;19:231-7. doi:10.1023/ B:EJEP.0000020446.57845.b0

2. Piepoli MF, Hoes AW, Agewall S, et al, ESC Scientific Document Group. 2016 European Guidelines on cardiovascular disease prevention in clinical practice: The Sixth Joint Task Force of the European Society of Cardiology and Other Societies on Cardiovascular Disease Prevention in Clinical Practice (constituted by representatives of 10 societies and by invited experts). Developed with the special contribution of the European Association for Cardiovascular Prevention & Rehabilitation (EACPR). Eur Heart J 2016;37:2315-81. doi:10.1093/eurheartj/ehw106

3. National Institute for Health and Care Excellence. Cardiovascular disease: risk assessment and reduction, including lipid modification. CG181. London: NICE (UK); 2014. [cited 2018 Jan 15]. https://www. nice.org.uk/guidance/cg181.

4. Goff DCJr, Lloyd-Jones DM, Bennett G, et al, American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2013 ACC/AHA guideline on the assessment of cardiovascular risk: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;63(25 Pt B):2935-59. doi:10.1016/j. jacc.2013.11.005 Goff DCJr, Lloyd-Jones DM, Bennett G, et al, American College of Cardiology/American Heart Association Task Force on Practice Guidelines. 2013 ACC/AHA guideline on the assessment of cardiovascular risk: a report of the American College of Cardiology/ American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol 2014;63(25 Pt B):2935-59. doi:10.1016/j. jacc.2013.11.005

5. Ueda P, Lung TW, Clarke P, Danaei G. Application of the 2014 NICE cholesterol guidelines in the English population: a crosssectional analysis. Br J Gen Pract 2017;67:e598-608. doi:10.3399/ bjgp17X692141

6. Han BH, Sutin D, Williamson JD, et al, ALLHAT Collaborative Research Group. Effect of Statin Treatment vs Usual Care on Primary Cardiovascular Prevention Among Older Adults: The ALLHAT-LLT Randomized Clinical Trial. JAMA Intern Med 2017;177:955-65. doi:10.1001/jamainternmed.2017.1442

7. Olafsdottir E, Aspelund T, Sigurdsson G, et al. Effects of statin medication on mortality risk associated with type 2 diabetes in older persons: the population-based AGES-Reykjavik Study. BMJ Open 2011;1:e000132. doi:10.1136/bmjopen-2011-000132

8. Ryan A, Heath S and Cook P. Primary prevention with statins for older adults. BMJ 2018;362:k3695 doi: 10.1136/bmj.k3695

Find this article online at BMJ

Facebook Comments

Register

We’re glad to see you’re enjoying PACE-CME…
but how about a more personalized experience?

Register for free