Exercise may help older adults stave off heart failure by protecting against early stages of damage, a longitudinal study showed.

Compared with the most sedentary seniors, the most physically active were 50% to 70% less likely to see increases in markers of cardiac injury over 2 to 3 years, Christopher R. deFilippi, MD, of the University of Maryland in Baltimore, and colleagues found.

New onset heart failure over the subsequent decade was dose-dependently linked to physical inactivity in the observational cohort, the group reported online in the Journal of the American College of Cardiology.

“These findings suggest that moderate physical activity has protective effects on early heart failure phenotypes, preventing cardiac injury and neurohormonal activation,” they wrote.

The mechanism may be by reducing pathological left ventricular remodeling and increasing arterial elasticity, resulting in less stress on the left ventricular wall and less cardiac injury, they proposed.

The observational results couldn’t determine causality or rule out confounding from healthier individuals being more prone to be active, Christopher M. O’Connor, MD, and Tariq Ahmad, MD, MPH, both of Duke University Medical Center in Durham, N.C., cautioned in an accompanying editorial.

Yet, exercise is a promising and appealing strategy, especially for high-risk populations who don’t yet have detectable structural heart disease, they noted.

“At present, the totality of evidence from observational studies and randomized, controlled trials suggests that exercise is good for the heart, even in the elderly,” they concluded, calling for validation in an intervention trial with appropriate controls and quantitative measures, such as 6-min walk distance.

DeFilippi and colleagues’ study included 2,933 individuals age 65 and older with biomarker measures at baseline and 2 to 3 years later as part of the larger Cardiovascular Health Study, a prospective, observational study done in four U.S. communities.

More active individuals based on a composite score for self-reported physical activity and walking pace were less likely to have significant increases in the cardiac injury markers.

The proportion of participants with a more than 25% increase in N-terminal pro-B-type natriuretic peptide (Nt-proBNP) from baseline to a level of at least 190 pg/ml reached 37% in the low activity group compared with 20% in the high activity group (P<0.001).

The proportion with at least a 50% rise in high-sensitivity troponin T was 30% among low-activity seniors versus 11% among the highly active (P<0.001).

After full adjustment for demographics and comorbidities, a significant rise in NT-proBNP was 50% more likely for the least versus most active individuals (odds ratio 0.50, 95% confidence interval 0.33 to 0.76).

The fully adjusted risk of a significant rise in high-sensitivity troponin T was 70% higher with the lowest composite activity score versus the highest (OR 0.30, 95% CI 0.16 to 0.55).

Over a median 10 years of follow-up after the second biomarker measurement, heart failure onset was more common with lower baseline physical activity.

For example, the rate of incident heart failure was 8 per 100 person-years in the low activity group who saw a rise in troponin T compared with less than 3 per 100 person-years in the high activity group with rising troponin T.

While the effect was particularly strong among participants with rising cardiac marker levels, the trend was statistically significant across all groups (P=0.02 to P=0.001).

“The possibility that biomarker measurement might provide an objective assessment of exercise efficacy, for which clinicians currently have no reliable measure, is an exciting proposition and deserves further evaluation with a controlled trial,” the editorialists pointed out.

The researchers acknowledged that the use of self-reported leisure physical activity and walking pace was a limitation that may have led to underestimation of effects.

Also, physical activity may have simply been a marker rather than a causal factor in cardiac health, they noted.

However, similar results were found in a sensitivity analysis excluding those with major comorbidities and participants who perceived their he

From: Medpage Today