Rethinking Endpoints: The Rise of Function

dodson%20headshotThe American Heart Association recently released a Scientific Statement on prioritizing functional capacity as an end point for treating older adults with cardiovascular disease.  A major rationale is that older patients repeatedly cite preservation of physical function as an outcome that matters most to them; for example in a landmark study by Fried et al. in 2002, survey respondents (older adults with limited life expectancy) reported that nearly three quarters would decline a treatment if the outcome was survival with severe functional impairment.

The AHA Statement highlights some key concepts when considering how to think about functional capacity in our everyday practice. I have highlighted several which I think are especially important:

  1. Function in older adults (and functional decline) is multifactorial. Function is determined not only by cardiovascular health, but by other organ systems including skeletal muscle, bone, lungs, and brain. For example, cognitive impairment may cause significant functional impairment despite normal cardiac output. This underscores why Geriatric Cardiologists aim to “think outside the heart” in addressing older patients’ symptoms.
  2. Trials that move beyond the traditional endpoints of death and/or cardiac events may be particularly relevant to older adults. Not many trials to date have accomplished this; however the authors cite the ASPREE trial (Aspirin in Reducing Events in the Elderly) as a novel example, using a primary end point of disability-free life (dementia and persistent disability).
  3. There are many domains of function, including aerobic, strength, balance, and cognition. Each domain also has multiple ways to measure it. It is simply impractical to measure all domains in everyday clinical practice. But a multi-domain assessment such as the Short Physical Performance Battery (SPPB), which assesses balance, mobility, and gait speed, can be completed in 10-12 minutes. I would expect these assessments to become more commonplace is specific settings, such as preoperative risk evaluation.

Finally, the article also discusses the critical need for interventions to improve or maintain function in older adults. Given the heterogeneity of abilities in older patients, rather than a “one size fits all” approach, these are best tailored towards specific goals (e.g. climbing stairs, household chores). A key role for Geriatric Cardiology will be to evaluate which interventions work best, and figure out how to embed them in everyday clinical practice.

By: John Dodson, MD