Cardiac Rehab Tied to Fewer Hospitalizations, Deaths After Valve Surgery

Use of cardiac rehabilitation after open heart valve surgery is associated with lower rates of hospitalization and mortality in the year after discharge, an analysis of Medicare data shows.

Mortality was an absolute 4.2% lower among patients who participated in cardiac rehab, with a relative 34% lower rate of hospitalizations, researchers report.

Those differences are similar to what has been seen in studies of cardiac rehab for other types of patients, senior author Justin Bachmann, MD (Vanderbilt University Medical Center, Nashville, TN), noted to TCTMD. “This does suggest that for centers that want to improve their outcomes, want to decrease hospitalizations, focusing on improving cardiac rehab enrollment could be a real strategy for that.”

And the data indicate that there’s a real opportunity to boost participation in rehab programs after valve surgery: fewer than half of patients in this study (43.2%) signed up despite eligibility under Medicare coverage.

“Even though around 40% is sort of high comparatively among other eligibility diagnoses, there’s still a lot of room to improve that number,” Bachmann said. “And if that number is improved, then we can improve outcomes, including hospitalizations and mortality.”

Commenting for TCTMD, Randal Thomas, MD (Mayo Clinic, Rochester, MN), pointed out that “the evidence for benefits of cardiac rehabilitation has been mounting over the past few decades, and there’s a pretty rich supply of research showing that patients who have experienced a cardiac event feel better, function better, live longer, and do better on almost any measure you can look at if they participate in an organized and systematic approach to rehabilitation and prevention after their event. And it’s not surprising. It’s supplying treatments of known benefit to patients who need them.”

He said there are some patient groups for which the evidence regarding the impact of cardiac rehab is more limited, however, and patients undergoing heart valve surgery is one of them. “So that’s an important contribution of this new study that adds some really important evidence to a group of patients where the evidence has been a bit lacking,” Thomas said.

The study, with lead author Devin Patel, MD (Vanderbilt University Medical Center), was published online October 23, 2019, ahead of print in JAMA Cardiology.

Racial/Ethnic Disparities Seen

Overall, use of cardiac rehabilitation is “pretty dismal” in the United States, Bachmann said, with just 20% to 30% of patients with various indications—acute MI, heart transplant, CABG, and cardiac valve surgery—participating. But, until now, there hadn’t been a national-level study of cardiac rehab after heart valve surgery, an indication that gained Medicare coverage in 2006.

In this new analysis, the investigators looked at data on 41,369 fee-for-service Medicare beneficiaries (median age 73 years; 40.9% women) who underwent open surgery involving the aortic, mitral, tricuspid, or pulmonary valve in 2014 and who survived for more than 30 days after discharge. More than one-third (36.2%) underwent concomitant CABG.

Overall, roughly four out of every 10 patients enrolled in cardiac rehab, with participants attending a median of 32 sessions.

However, the likelihood of enrollment was not consistent across groups. Patients from racial/ethnic minority groups—including Asians, African-Americans, Hispanics, and Native Americans—were less likely than their white counterparts to sign up. On the other hand, those who underwent concomitant CABG and those living in the Midwest were more likely to enroll.

The racial/ethnic disparities are “pretty striking,” Bachmann said, “and so I think medicine as a whole [needs] to do better about improving these disparities and getting more of these patients to enroll in cardiac rehab programs.”

Through the first year after discharge, 6.6% of patients died and 41.0% were hospitalized at least once. Participation in cardiac rehab was associated with lower risks of both mortality (HR 0.39; 95% CI 0.35-0.44) and rehospitalization (HR 0.66; 95% CI 0.63-0.69), with generally consistent findings across groups defined by type of valve surgery, use of concomitant CABG, and discharge destination. Several sensitivity analyses meant to account for observed and unobserved confounding provided similar results as well.

What’s Driving Better Outcomes?

In their paper, the researchers list several mechanisms by which cardiac rehab might reduce hospitalizations, “including increased surveillance by cardiac rehab staff who might alert the patient’s clinician in the event of deterioration, encouragement of medication adherence, and improvement in functional status.”

Bachmann cautioned against drawing conclusions about causality based on observational data, but for Philip Ades, MD (University of Vermont Medical Center, Burlington), whose office overlooks the cardiac rehab area at his center, the reason why hospitalizations are lower in program participants is clear: issues like shortness of breath or chest pain that would normally land a patient in the emergency room—and ultimately the hospital—are addressed by doctors and other staff working in cardiac rehab before they get to that point. “It’s very obvious to me how cardiac rehab prevents rehospitalizations,” Ades told TCTMD, adding that keeping patients out of the hospital “saves a ton of money.”

What’s less clear is how cardiac rehab would reduce 1-year mortality after heart valve surgery, Ades said, noting that information on some important potential confounders, like smoking, was not reported in the paper. “The mortality benefit to me is suggestive and I like to see it, but I’m a little concerned about residual bias,” he said.

For Thomas, the difference in mortality could be related to better control of cardiovascular risk factors among patients enrolled in cardiac rehab or to earlier detection of issues that might be tied to mortality, including depression and abnormal chest X-ray findings indicative of cancer.

He, too, cautioned that there are inherent biases in observational studies. “But the investigators did a good job of correcting for those potential sources of bias as much as is possible in an observational study,” he said. “So I’m very confident that the findings reflect a true impact.”

Boosting Enrollment

The question then becomes: how can the medical community get more patients into cardiac rehab programs?

Ades said the top two strategies for doing that are automatic or computerized referral in eligible patients and use of a liaison—a nurse or some other member of the cardiac rehab team—to meet with patients and discuss the benefits of signing up. Both approaches are designed to overcome the problem of busy physicians forgetting or not having time to discuss the importance of cardiac rehab programs with their patients. If there is time, however, a strong recommendation from a physician to his or her patient is powerful predictor of cardiac rehab participation, Ades pointed out.

Bachmann agreed that a direct recommendation from a physician is one way to get more patients to sign up for rehab, along with improving insurance coverage to remove copays that might be prohibitive for some patients and implementing more flexible scheduling to increase the convenience of attendance.

Thomas noted that there are barriers to cardiac rehab at the patient, clinician, and health system levels. Patients “may live far away from a program, they may not have insurance coverage, they may feel like they need to get back to work, they may not sense the importance of the program, they may not be aware of the benefits,” he explained. “Providers are busy, sometimes forgetting to refer patients and maybe not realizing how important it is to refer them. And health systems sometimes lack the convenience for hours or locations to make it better and easier for patients to get into a program.

“The good news,” he continued, “is that several studies have shown that many of those barriers can be overcome with a systematic approach to providing cardiac rehabilitation to patients.”

Thomas and LaPrincess Brewer, MD (Mayo Clinic), conclude in an accompanying commentary, “As cardiac rehabilitation delivery methods, quality-improvement practices, and coverage policies continue to evolve, healthcare practitioners and policy makers must implement more effective and innovative strategies to improve delivery of cardiac rehabilitation services to all eligible patients, including those patients undergoing heart valve surgery. Little by little, as additional scientific evidence and innovative delivery strategies continue to expand, such efforts will help patients travel far on the road to optimal rehabilitation and secondary prevention outcomes.”