Dr Aung Zaw Zaw Phyo, a research fellow at the School of Public Health and Preventive Medicine at Monash, specialises in how we age and the myriad health problems age can bring.

Now, he’s led large-scale, landmark research showing for the first time that older people living in the community – not in a hospital – can become more frail or at risk of increased frailty after a cardiovascular disease “event” such as a heart attack or a stroke. 

The research team studied  19,111 people, who were mostly over 70 and living independently in the community in Australia or the US, for 11 years.

The data came from people already enrolled in the  Monash-led ASPREE trial into aspirin and healthy ageing, funded by the Australian and US governments. The participants had no prior cardiovascular events.

“It feels meaningful,” Dr Phyo tells Lens. 

“The strength of this work lies in the ASPREE longitudinal data over 11 years, which allows us to explore frailty as a dynamic process rather than a single point in time. 

“Being a part of such a large, landmark ASPREE study is a true privilege. It’s incredibly rewarding to see our collaborative teamwork contribute to a better understanding of how well people live after heart disease, which also highlights that healthcare providers should be aware of frailty as a part of cardiovascular disease [CVD] management.”

The work was supported by a Monash Early Career Postdoctoral Fellowship. Dr Phyo is currently assisted  by a National Heart Foundation of Australia Postdoctoral Fellowship.

The post-survival impact

The primary message from his work is that there’s more to heart disease than cheating death.

“Heart disease is one of the most common conditions in later life. When we think of heart disease, the primary concern for most people is survival. But it’s also important to know what happens after someone survives,” he says.

The new research published in the European Journal of Preventive Cardiology and the Canadian Journal of Cardiology reveals that the impact of experiencing an “incident CVD event” on becoming frail or the trajectory of frailty over time. 

The research’s significance is shown in accompanying editorials  in the journals. Among the 19,000-plus older people studied, 1934 people experienced a CVD event over 11 years of follow-up. 

The findings are stark. Frailty worsens immediately after a heart event, but the burden of frailty also continues to increase over time. Almost half (45%) of people who experienced a CVD developed frailty at an average of 2.6 years after the event.

Those most at risk were individuals with early signs of frailty (“pre-frail”), women, those over 80, living alone and living either regionally or remotely, and those taking five or more medications. 

“Ageing is a biological journey that everyone will experience one day,” Dr Phyo says. “It’s a part of our life course. Understanding the process of ageing and why some individuals experience multiple health conditions while others remain healthy helps us find ways to lead healthier, more meaningful lives for everyone.”

Age-related deterioration

Frailty, he says, can be simply understood as a “common chronic condition in older people characterised by the accumulation of age-related deterioration in biological systems.” 

These deteriorations increase vulnerability to disease, falls, hospitalisation, worsening mobility, functional dependence (reduced ability in basic tasks) and death.  

“If someone experiences frailty,” he says, “it indicates that their body is less resilient – reduced muscle mass and strength, lower energy production, and slower repair and recovery processes.”

Frailty was estimated annually using two accepted approaches. One is called a deficit-accumulation frailty index. The other is the Fried phenotype (known as Fried), named after US geriatrician and epidemiologist Dr Linda Fried.  

The frailty index looks at diagnosed health conditions, biomarkers, pathology, physical health, wellbeing and function, and provides a system-wide measure of frailty. Fried captures five specific physical functioning measures – slow gait or walking speed, handgrip strength, low weight, exhaustion and low levels of physical activity. 

Gender differences revealed

Previously, most studies of frailty only involved CVD patients in hospital for pacemaker and/or defibrillator procedures, or heart surgery. This community-based study also uncovered gender differences, finding that women experienced more old-age frailty than men. 

“This finding could be driven by sex differences in biological disparities, physiological responses to CVD events and hormonal changes. 

“For example, after menopause, women usually experience a significant drop in oestrogen levels, which makes them more susceptible to reduced bone density, muscle mass and ultimately osteoporosis, limiting their physical resilience. All these conditions, along with CVD events, likely contribute to women experiencing more frailty than men. 

“Our findings of gender difference also reflect the male-female health-survival paradox where females live longer and are more likely to experience disabilities and disease burdens, whereas men die quicker.”

Dr Phyo says healthcare providers are the target audience here, to “be aware of frailty” as part of CVD management, including frailty screening. 

“Our findings reveal clear evidence of an increased burden of frailty following a CVD event. Therefore, our findings, coupled with prior evidence, underscore the importance of frailty screening in people with CVD to identify those at risk of further adverse outcomes and to pinpoint targets for interventions through medical evaluation and geriatric assessment.”