Short-term Changes in Exercise Habits Can Alter Long-term Prognosis of Stable CAD Patients

For patients with stable CAD, shifts in exercise habits over a 2-year period appear to influence their risk of dying from heart disease years later, Finnish researchers have found. Of note, patients in the study who started out as inactive but began to exercise within the first 2 years had no greater risk of cardiac death than those who are active the whole time.

“Even minor changes—ie, changing from sedentary behavior to at least irregularly active or vice versa—are associated with altered risk for cardiac death,” said senior author Antti Kiviniemi, PhD (Oulu University Hospital, Finland), an exercise physiologist.

When counseling an inactive individual with CAD, clinicians should suggest a gradual approach to exercise since greatly increasing physical activity levels could up cardiac risk, he told TCTMD via email. “It should be underscored to sedentary patients that even a minor increase and subsequent maintenance of physical activity [offers] benefits in terms of health, while regular moderate-intensity physical activity is optimal, as previously documented.”

Kiviniemi, lead author Minna Lahtinen, MSc (Oulu University Hospital), and colleagues sought to understand how getting more or less leisure-time exercise over the long haul might affect the prognosis of patients with angiographically documented, stable CAD. They enrolled 1,746 individuals, classifying them at baseline as inactive, irregularly active, active, or highly active. Leisure-time physical activity was categorized again at 2 years.

After a median follow-up of 4.5 years, 3.9% of the patients had died of cardiac causes. Individuals who started out as inactive and stayed that way had the highest risk (16%), followed by those who became inactive during the 2-year period (8%) and those who were at least irregularly active the whole time (2%).

After adjustment for numerous factors—age, sex, body mass index, diabetes, prior MI, LVEF, degree of angina, CV events during the first 2 years, smoking, and drinking alcohol—patients who stayed inactive had the highest risk of cardiac death compared with those who were active the whole time. However, those who were once active but did not keep it up also had elevated risk. People who shifted from being sedentary to being active had no greater risk of cardiac death than those who were active at the outset and stayed active.

Cardiac Death Risk at Median Follow-up of 4.5 Years

*Compared with active-active.

Patients who started out as sedentary and continued to be inactive tended to have a greater likelihood of cardiac death compared with those who had become active by 2 years, although the difference fell shy of statistical significance (adjusted HR 4.4; 95% CI 1.0-19.6).

However, despite this good news that making lifestyle changes can bear fruit, the researchers caution that further analyses showed “risk related to the changes in [leisure-time physical activity] are substantially related to baseline exercise capacity.”

Asked about how this relates to the overall conclusions of the study, Kiviniemi pointed out that physical activity’s link to prognosis was at least “partly independent of baseline exercise capacity.”

What this may indicate, he said, is “that physical activity improves prognosis beyond exercise capacity, probably through its multiple effects on cardiometabolic health and well-being. In the current study, this remained partly unclear due to lack of follow-up measurements of exercise capacity.”