Secondary prevention medication after myocardial infarction: persistence in elderly people over the course of 1 year

Abstract

Aims: Persistent use of guideline-recommended drugs after acute myocardial infarction (AMI) is frequently reported to be inadequate in the elderly and scarce knowledge exists about factors that influence persistence in outpatient care. Our aim was to evaluate drug use and its predictors in survivors of AMI above 64 years from hospital discharge to 1-year post-AMI.

Methods: In a single-centre randomised controlled trial, discharge medication of 259 patients with AMI was obtained from medical records at hospital stay. Follow-up drug use and use of the healthcare system were self-reported to study nurses over 1 year in 3-month intervals. Predictors for persistence were modelled with multivariate logistic regression analysis considering demographics, co-morbidities and treatment characteristics.

Results: At discharge, 99.2 % of the patients used anti-platelets, 86.5 % beta blockers, 95.0 % statins and 90.4 % angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. Use of the combination of all four drug classes decreased from discharge to 1 year post-AMI from 74.1 to 37.8 % and was significantly reduced by age ≥75 years (odds ratio [OR] 0.49; 95 % confidence interval [CI] 0.29-0.85) and ten or more visits with general practitioners (GPs) over 1 year (OR 0.29; 95 % CI 0.17-0.51). Persistence from month 3 to 12 was significantly associated with drug use at discharge for the single drug classes, but not for the drug combination.

Conclusion: Older age and frequent GP visits are associated with decreased use of the guideline-recommended drug combination after AMI. Further research is needed to specify underlying reasons and develop measures to improve persistence.