Guideline-directed medical therapy boosts survival in the oldest heart attack patients

Researchers have found that prescribing guideline-directed medical treatment (GDMT), regardless of the number of medications, can improve survival rates in patients 90 years of age and older following their first heart attack, with the greatest benefit observed in patients who received all four recommended post-acute myocardial infarction (AMI) therapies. These include beta-blockers, antiplatelets, lipid-lowering drugs, and renin-angiotensin-aldosterone system inhibitors. The findings of the article appearing in the Canadian Journal of Cardiology, published by Elsevier, can guide future clinical approaches to managing first-onset AMI in nonagenarians and centenarians.

Life expectancy has been steadily increasing over time. In 2021, there were more than 861,000 Canadians who were aged 85 and older, an age group that is rapidly increasing in developed countries around the world. Since age is an independent risk factor for developing cardiovascular disease, there is a growing need for guidance in the management of this elderly population.

The lead investigator of the article "Guideline-directed Medical Therapy in Nonagenarians and Centenarians (≥ 90 Years Old) After First-onset Myocardial Infarction—a National Registry Study," Ching-Hui Sia, MBBS, Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, and Department of Cardiology, National University Heart Centre Singapore, says, "As clinicians, we are often hesitant to prescribe GDMT for nonagenarians and centenarians presenting with AMI. This reluctance is driven by concerns over polypharmacy, high comorbidity burden, frailty, and the risk of adverse drug reactions, such as postural hypotension, which can lead to falls. We sought to clarify, in real-world clinical practice, whether prescribing more medications to this age group might actually be associated with worse survival outcomes."

The researchers conducted a retrospective cohort study using Singapore's National Myocardial Infarction Registry, including 3,264 patients aged 90 years and above who experienced a non-ST elevation myocardial infarction between 2007 and 2020. They compared survival among groups stratified by the number of GDMTs prescribed at discharge (0, 1-2, 3, or 4). The analysis demonstrated that prescribing any number of GDMTs was associated with improved survival, with the greatest benefit observed in patients who received all four recommended therapies.

This is the largest study to date evaluating post-myocardial infarction (MI) outcomes in patients aged 90 and above using data from a national registry in a high-performing, well-resourced healthcare system. The timely and important findings offer real-world evidence that can help inform more confident prescribing practices for very elderly patients.

Coauthor of the accompanying editorial "Medical Management for Patients 90 Years Old and Up After Acute Coronary Syndrome—Never Too Old," Karen B. Ho, MD, Division or Cardiology, Department of Medicine, Mazankowski Heart Institute, Edmonton, notes, "Despite the significant attention given to the adverse effects of polypharmacy, underprescription in the elderly is an increasingly recognized and important problem. The appropriate acute coronary syndrome (ACS) management in this age group is challenging owing to a lack of evidence and concerns regarding the tolerability and safety of medications. The current study encouragingly suggests that GDMT after ACS is associated with improved survival in this very advanced age group, and the more complete the therapy, the better. Therefore, in the absence of contraindications, clinicians should not withhold GDMT on the basis of age alone."

The editorial's coauthor Michelle M. Graham, MD, Division or Cardiology, Department of Medicine, Mazankowski Heart Institute, Edmonton, adds, "At the heart of the discussion is to consider what older adults value. In this study, the primary outcome was all-cause mortality. However, for patients of very advanced age, quality of life may be as or more important as their quantity of life. Avoiding repeat emergency room visits and rehospitalizations and maintaining independence may be bigger priorities. It is important to consider how additional medications can help elderly patients achieve their goals of care. Future research on the management of cardiovascular disease in older adults should emphasize the effects of guideline-directed medical therapy on patient-important outcomes, such as functional and cognitive capacity and days out of hospital."

Dr. Sia concludes, "Our findings suggest that physicians should carefully assess any decision to not manage a patient aggressively with GDMT unless there is a well-founded reason. Advanced age alone does not appear to be an adequate reason to withhold the prescription of GDMTs. Of course, the benefits of GDMTs must always be weighed against the potential risks when prescribing them to nonagenarians and centenarians in order to achieve the best therapeutic outcomes."