PHOENIX – Lower baseline fitness and greater decline in fitness over time are independently associated with a higher risk of heart failure in patients with diabetes, results from a large analysis showed.
“Diabetes is an important risk factor for the development of heart failure, and the diagnosis of diabetes in newly diagnosed cases of heart failure has been increasing,” Ambarish Pandey, MD, said at the Epidemiology and Prevention/Lifestyle and Cardiometabolic Health meeting. “Type 2 diabetes is associated with increased burden of traditional risk factors such as hypertension, kidney dysfunction, and dyslipidemia – each of which in turn increase the risk of both atherothrombotic disease as well as heart failure.”
Recent data from the Swedish National Diabetes Register have shown that optimal management of these risk factors in patients with type 2 diabetes can actually mitigate the risk of atherosclerotic events such as acute MI, but the risk of heart failure does not significantly lower with optimal management of these traditional cardiovascular risk factors (N Engl J Med. 2018;379:633-44). “These findings highlight that novel approaches that go beyond just managing traditional cardiovascular risk factors are needed for prevention of heart failure in patients with type 2 diabetes,” said Dr. Pandey, of the division of cardiology at the University of Texas Southwestern Medical Center, Dallas. “Our group has demonstrated that physical inactivity and low levels of fitness are associated with a higher risk of heart failure. We have also shown that the protective effect of physical activity against heart failure risk is stronger against heart failure with preserved ejection fraction, which is a subtype of heart failure that is increasing in prevalence and has no effective therapies.”
Dr. Pandey and his colleagues set out to test the research hypothesis that fitness decline and increases in body mass index over time are significantly associated with a higher risk of heart failure. To do this, they drew from the LookAHEAD Trial, a multicenter analysis of 5,145 overweight or obese patients with type 2 diabetes who were randomized to an intensive lifestyle intervention or to usual care. The intervention consisted of a caloric intake goal of 1,200 to 1,800 kcal per day and engaging in at least 175 minutes per week of physical activity. Participants were stratified into one of three fitness group levels: low, moderate, and high, from 5 metabolic equivalents (METs) in the lowest fitness tertile to 9 METs in the highest fitness tertile. The primary outcome of the trial was adverse cardiovascular events. The intervention was implemented for almost 10 years, and patients were followed for up to 12 years from baseline.
The heart failure outcomes were not systematically adjudicated in the primary LookAHEAD trial, so Dr. Pandey and colleagues conducted an ancillary study of all incident hospitalizations in the study and followed them for 2 additional years. Overall, the researchers identified 257 incident heart failure events. The cumulative incidence of heart failure for the usual care versus the intensive lifestyle intervention arm was not statistically different (an event rate of 4.53 vs. 4.32 per 1,000 person-years, respectively; hazard ratio, 0.96). “This demonstrated that the intensive lifestyle intervention in the LookAHEAD trial did not significantly modify the risk of heart failure,” Dr. Pandey said.
However, an adjusted analysis revealed that the risk of heart failure was 39% lower in the moderately fit group and 62% lower in the high fit group, compared with the low-fitness group. Among heart failure subtypes, the risk of heart failure with preserved ejection fraction (HFpEF) was 40% lower in the moderately fit group and 77% lower in the high-fitness group. On the other hand, baseline level of fitness level was not associated with risk of heart failure reduced ejection fraction (HFrEF) after the researchers adjusted for cardiovascular risk factors.
Next, Dr. Pandey and his colleagues used Cox modeling to examine the association of baseline and longitudinal changes in fitness and BMI with risk of heart failure. For change in fitness and BMI analysis, they used the 4-year follow-up data in 3,092 participants who underwent repeat fitness testing and had available data on BMI. They excluded patients who developed heart failure within the first 4 years of the study.
The mean age of the ancillary study population was about 60 years, and there was a lower proportion of women in the high fitness tertile (41%). The researchers observed a graded, inverse association between higher fitness levels and lower risk of heart failure such that increasing fitness from baseline was associated with a substantial decrease in the risk of heart failure. Specifically, a 10% decline in fitness over the 4 years of follow-up was associated with a 11% increase in the overall risk of heart failure (HR, 1.11). “This was largely consistent with the two heart failure subtypes,” he said. Similarly, a 10% increase in BMI over the 4 years of follow-up was associated with a 25% increase in the overall risk of heart failure (HR 1.25). On the other hand, a 10% decrease BMI was associated with a 20% decrease in the risk of heart failure (HR .80). This was also largely consistent for both heart failure subtypes. According to co-lead investigator Kershaw Patel, MD, “these findings suggest that therapies targeting large and sustained improvements in fitness and weight loss may modify the risk of heart failure among patients with diabetes.”
“Lower fitness at baseline was more strongly associated with the risk of HFpEF vs. HFrEF, and greater weight loss over follow-up is associated with a lower risk of heart failure independent of changes in other risk factors,” Dr. Pandey concluded at the meeting, which was sponsored by the American Heart Association.
In an interview, session moderator Joshua J. Joseph, MD, said that it remains unclear what type of setting is ideal for carrying out cardiorespiratory fitness in this patient population. “What is the supervision needed for that to occur?” asked Dr. Joseph, of The Ohio State University, Columbus. “Can patients do this on their own, or do they need guidance? What is the best approach? That’s the question we all have to answer individually in our own communities.”
Dr. Pandey reported having no disclosures.
SOURCE: Pandey A. Epi/Lifestyle 2020, Abstract 16.