By 2035 the number of people over age 65 in the U.S. will outnumber children under age 18 for the first time. Among this growing older adult population, nearly 4 out of 5 individuals will have one or more forms of cardiovascular disease (CVD).
Given our aging population, a key area of research has been to understand the effects of CVD on “healthspan,” which is defined as aging without major physical or cognitive limitations. Plausibly, CVD leads to accelerated vascular aging through pathways that include chronic inflammation and oxidative stress. While studies to date have broadly suggested an association between CVD and physical and cognitive impairment, we don’t know which CVD subtypes (e.g., stroke or heart failure) have the most influence. We also do not know whether having a new CVD event earlier or later in life leads to greater impairment.
To help answer this question, we used data from the Health and Retirement Study (HRS) which is a large, well-characterized U.S. cohort study that includes over 42,000 participants enrolled between 1992 – 2018. In order to better understand the relationship between new-onset CVD and subsequent impairments, we studied 16,679 HRS participants who were age ≥65 years at study entry and looked at physical impairment using activities of daily living, and cognitive impairment using the Langa-Weir Classification of dementia. We then analyzed effects by four major CVD subtypes (atrial fibrillation, congestive heart failure, ischemic heart disease, stroke) as well as age at CVD diagnosis (65-74, 75-84, ≥85).
There were two key findings: first, among CVD subtypes the diagnosis of stroke consistently (and expectedly) demonstrated the greatest odds of subsequent physical and cognitive impairment. However other conditions that may intuitively have less influence on these outcomes – for example, congestive heart failure – were also associated with them. Second, we found that the oldest (≥85) age-at-diagnosis subgroup had the highest risk of both physical and cognitive impairment.
In addition to better understanding the epidemiology between CVD onset and subsequent impairments, our findings may help inform practice guidelines for the oldest adults. Using statin therapy for primary prevention as an example, the 2018 American College of Cardiology (ACC) / American Heart Association (AHA) guidelines weigh heavily on patient-clinician discussions given the limitations of many clinical trials. The findings from our study can help inform these discussions by showing that CVD events have a major impact on functional status, highlighting the additional benefits of prevention over more traditional outcomes (e.g., recurrent myocardial infarction), especially for the “oldest old.”
Our results were presented at the recent American Geriatrics Society Annual Meeting and are now published in the Journal of Gerontology: Series A.
Katherine Stone is a Medical Student at NYU Grossman School of Medicine.