Delays in Referral and Enrolment Are Associated With Mitigated Benefits of Cardiac Rehabilitation After Coronary Artery Bypass Surgery

Abstract

Background-Cardiac rehabilitation (CR) is recommended after coronary artery bypass graft surgery; however, the consequences of longer wait times to start CR have not been elucidated. Method and Results-Cardiopulmonary, demographic, and anthropometric assessments were conducted before and after 6 months of CR in consecutively enrolled patients from January 1995 to October 2012. Wait times were ascertained from referral forms and charts. Neighborhood characteristics were ascertained using census data and cross-referencing with patients' home geographic location. Among 6497 post-coronary artery bypass graft participants, mean and median total wait time (time from surgery to first exercise session) was 101.1±47.9 and 80 days, respectively. In multiple linear regression, correlates of longer total wait time and the 2 wait-time phases, time from surgery to CR referral and time from CR referral to first exercise session, were determined. Factors influencing longer wait times included female sex, greater age, being employed, less social support, longer drive time to CR, lower neighborhood socioeconomic status, higher systolic blood pressure, abdominal obesity, and a complex medical history. After adjusting for correlates of delayed entry, longer wait time for each of the total and 2 wait-time phases was significantly associated with less improvement in cardiopulmonary fitness (VO 2peak ; β=−0.165, P<0.001), body fat percentage (β=0.032, P<0.02), resting heart rate (β=0.066, P<0.001), and poorer attendance to CR classes (β=−0.081, P<0.001) and completion rate (β=2.741, P<0.001). Conclusions-Strategies for timely access to CR at each phase of the process are important given the negative impact that wait time has on key clinical outcomes. This is relevant because optimizing VO 2peak and attendance to CR has been shown to confer a mortality advantage. (Circ Cardiovasc Qual Outcomes. 2015;8:608-620.

Another Piece of the Puzzle

“…6 Factors associated with longer wait times for CR included female sex, older age, being employed, less social support, longer commute to CR, lower neighborhood socioeconomic status, higher systolic blood pressure, abdominal obesity and a complex medical history. In this study, longer wait times were not just associated with poorer adherence to CR, but also less improvement in cardiovascular fitness and cardiovascular risk reduction.…”

“…Marzolini et al 6 , in this issue of Circulation: Cardiovascular Quality and Outcomes, have identified another piece of the puzzle in accessing CR by investigating wait times. To date, the relationship between longer wait times and the commencement of CR has not been well described, and this analysis may elucidate how system-based factors can moderate access to evidence-based care and as a consequence health outcomes.…”

“…But in countries, such as Australia, Canada, and the United Kingdom, where CR is readily accessible and reimbursed, participation and program completion remain a challenge. 6,8 Therefore, if we want to promote CR in the United States, we need to take into consideration not just reimbursement but systems and process issues; considering referral and wait times is an important part of the equation.…”

“…Marzolini et al emphasized that barriers are most apparent in women, the elderly, and those from lower socioeconomic status populations. 6 Ensuring access to CR will require integrated patient, provider, and system solutions. Continuing to document these barriers is no longer viable in the science of CR 14 ; we need to develop and test strategies to promote access to this evidencebased approach for improving cardiovascular outcomes.…”

Effects of exercise-based cardiac rehabilitation on cardiorespiratory fitness: A meta-analysis of UK studies

“…Omission of such basic data impact greatly on the interpretation of findings from studies (and reviews) as we cannot determine with accuracy the dose of exercise received. A delay in starting CR is associated with a decreased likelihood of uptake of CR [44]; it may also attenuate the benefits of CR for those who do attend [45]. Less than half of studies reported the time from event or surgery to start of CR [25,30,36,46].…”