Frailty and the Heart: Exploring the connection between frailty and heart disease treatments

Monday, June 27, 2016

As Canadian life expectancy increases, older patients and their caregivers face difficult questions regarding the risks and benefits of treatment options. Some treatments are more invasive than others: how can patients and healthcare providers decide which option is best?

School of Pharmacy Professor Colleen Maxwell and her PhD student Elizabeth Freiheit are addressing these concerns by examining a specific health concept: frailty. They’re part of a team that studied the impact of cardiovascular treatments on patient frailty. Their study, on which Freiheit is lead author, has been highlighted in the Journal of Circulation: Cardiovascular Quality and Outcomes, a top cardiology journal published by the American Heart Association.

What is frailty and why do we need to assess it?

“Frailty is a not a predetermined trait, but rather a dynamic state influenced by everyday choices,” writes clinical researcher Jonathan Afilalo in the editorial that profiles Maxwell and Freiheit’s study.

The study assesses frailty levels in 374 patients ages 60 or over, all of whom suffer from coronary artery disease (CAD). CAD results from plaque building up in the arteries and limiting oxygen-rich blood from reaching the heart. Dr. Maxwell and her colleagues measured frailty using a deficit method pioneered by Dalhousie University professors Kenneth Rockwood and Arnold Mitnitski.

Maxwell

To calculate frailty with the deficit method, researchers identify specific criteria as deficits and then tally how many deficits a patient has. Deficits were both physical – like significant weight loss, grip strength or walking speed (depicted left) – and cognitive – like depression or memory loss.

"Understanding an individual’s frailty," Maxwell explains, "is crucial for making decisions about their healthcare.

She adds that: “Frailty rises exponentially with age, and a higher frailty score usually tells us something about an older patient’s risk for poor outcomes (including lower quality of life) over and above simply knowing their age and illness profile."

Knowing a patient’s frailty score may influence the type of treatment or follow-up that is ideal for that patient. But in order to make those decisions, it’s vital to understand exactly how different treatment options impact an individual’s frailty level.

Frailty and Coronary Artery Disease Treatments: What’s the connection?

All 374 participants in the study had coronary artery disease and each received a different form of treatment for that disease. But did experiencing treatment make patients less frail or more frail?

Maxwell and her colleagues were one of the first groups to explore this connection. They looked at three types of treatment for CAD:

  1. Coronary Artery Bypass Graft Surgery – surgery to improve blood flow to the heart by inserting a healthy artery to bypass blocked arteries.
  2. Percutaneous coronary intervention (PCI) – non-surgical procedure that uses a thin flexible tube to insert a stent in the patient’s heart. The stent widens blood vessels that have been narrowed by plaque buildup, improving blood flow.
  3. Medical therapy (MT) – non-invasive treatment option that uses drug therapy to improve blood flow.

For all three options, the team assessed the frailty levels of patients before they experienced the treatment, and after the procedure for up to 30 months. In all cases, they found that, at first, frailty levels would decrease (improve) as patients’ symptoms improved following treatment. But after a period of 6-12 months, regardless of the kind of treatment, frailty levels would begin to rise (worsen) again. Also, patients who were 75 or older did not experience the initial improvement in frailty levels; instead, frailty continued to rise.

“We know that frailty rises with age, so it’s not surprising that the levels may continue to increase even post-surgery or post PCI,” Maxwell reflects. She adds:

But our findings suggest that older more vulnerable patients may be less likely to experience improvements in frailty status in the initial period following surgery, and this information may be important to decision-making about care and follow-up.

By revealing that frailty is a dynamic and potentially modifiable condition, and that an assessment of frailty  may help shape decisions about care and ongoing management, Maxwell and Freiheit demonstrates that frailty is a useful concept both for healthcare practitioners and for patients and caregivers who seek to be more involved in decisions about  their treatment options.