Sherrie Khadanga, M.D.

Khadanga's Research Aims to Enhance Adherence and Outcomes with Innovative Approaches

In medicine, cardiac rehabilitation (CR) programs are designed to improve the cardiovascular health of individuals who have experienced heart-related events such as heart attacks, surgeries, or chronic conditions. A comprehensive CR approach, which can include structured exercise training tailored to individual needs, education on heart-healthy living such as diet and weight management, and more, aims to aid recovery, lower the risk of future heart problems, and enhance overall quality of life for patients. While CR has been proven to be incredibly effective, there are still population pockets that struggle with receiving effective and adequate care. Larner College of Medicine Assistant Professor of Medicine Sherrie Khadanga, M.D., has recently addressed ways to improve CR methods in two different populations, addressing both age and socioeconomic status.

Khadanga was recently awarded her first R01 grant from the NIA for a project titled “Optimizing Aerobic Fitness and Functional Response to Exercise in Older Adults.” This project aims to combine high-intensity interval training (HIIT) and high-intensity resistance training (HIRT) to improve VO2peak and physical function in older patients needing cardiac rehabilitation. Traditionally, CR has used moderate-intensity continuous training (MICT) and moderate-intensity resistance training (MIRT) to improve functional capacity. Cardiovascular disease (CVD) is the leading cause of hospital-acquired disability in older adults, and many patients struggle to regain physical function. While MIRT and MICT help some, others see less benefit. HIIT has proven more effective, improving VO2peak—the maximum amount of oxygen the body can use during intense exercise—and muscle strength. Khadanga’s team, which includes co-investigators Mike Toth, Ph.D., and Phil Ades, M.D., will test the efficacy of combining HIIT and HIRT in a rigorous, randomized controlled trial (RCT). They will evaluate patients eligible for CR, with some undergoing detailed assessments to see how each training program affects the body at different levels.

“This study will change the way we implement exercise for adults and will allow us to see what changes occur on a cellular level in regard to high-intensity exercise,” said Khadanga. “It exemplifies the role of collaboration bridging clinical and basic science.”

Successfully completing these studies would challenge current clinical practices and promote a new multi-modal CR exercise approach, optimizing improvements in VO2peak, physical function, and clinical outcomes for older adults. This research would also provide a deeper understanding of how these exercises improve functional capacity. Proving the effectiveness of HIIT+HIRT within CR would strongly support using high-intensity exercise for both healthy older adults and various patient groups.

Khadanga’s research interests also extend into the socioeconomic determinants of health in CR. Her recent paper, “Improving Cardiac Rehabilitation Adherence in Patients With Lower Socioeconomic Status: A Randomized Clinical Trial,” published in JAMA Internal Medicine, explores how to best increase cardiac rehabilitation attendance among patients with lower socioeconomic status (SES). Despite the proven benefits of CR, it is severely underutilized in certain populations, specifically those with lower socioeconomic status. Khadanga’s research sought to address the efficacy of early case management and/or financial incentives for increasing cardiac rehabilitation adherence among patients with lower SES.

Working with Assistant Professor of Psychiatry and Psychology Diann Gaalema, Ph.D., Khadanga’s randomized clinical trial, conducted at the University of Vermont Medical Center (UVMMC), consisted of 192 participants and took place from December 2018 to December 2022. The patients were assigned to 1 of 4 conditions: usual care control, a case manager starting in-hospital, financial incentives for completing cardiac rehabilitation sessions, or both interventions. In her study, Khadanga’s team found that participants completed more sessions when financial incentives were added. Specifically, sessions completed rose from 11 out of 36 in the usual care group to 25 out of 36 with the addition of case management and financial incentives. Additionally, the number of participants finishing at least 30 sessions jumped from 11% in the usual care group to 62% with case management and financial incentives. Financial incentives, whether alone or combined with case management, significantly boosted adherence, while case management alone did not have much effect.

“The success of using financial incentives with this group matches what’s seen in other studies,” stated Khadanga, noting that financial incentives have been effective in improving various health-related behaviors, especially those related to attendance. Although this study didn’t focus on clinical outcomes—rather, it homed in on attendance—the entire cohort showed improvements in most clinical measures over time. Cardiorespiratory fitness, body composition, and depressive symptoms all improved, with better results linked to the number of sessions attended.