Footfalls mix with music and light chatter at the 2 p.m. cardiac rehab class at St. Mary Medical Center in Langhorne, Pa. In a bright second-floor room looking out over the hospital grounds, patients walk, row and bicycle through an aerobic routine designed to strengthen newly repaired hearts and set the tone for a vibrant recovery.

"The thinking here is definitely not, 'OK, your surgery is done, you're fixed,' " says Stacey Kance, 20, six weeks out from a mitrovalve prolapse repair and a surgical closure of a patent foramen ovale (PFO), an atrial wall defect discovered on the operating table. "The staff is here to guide you, but it's up to you to do the work."

A few treadmills down the line, Jackie Randleman, 81, speaks proudly of the 20 pounds she's lost since an angioplasty and cardiac catheterization in May, without counting a single calorie. Lively and upbeat, she's a born-again fanatic about sodium, trimming her intake to just 1,500 milligrams per day by avoiding her treasured soups, pasta sauces and salad dressings. Randleman makes the 25-minute drive from her home in Lawrenceville, N.J., to attend classes 3 times per week.

Kance and Randleman represent two divergent points on a rehab spectrum that's been proven to work, regardless of age. Researchers have known for decades that patients who undergo cardiac rehab after a heart-related event live longer and healthier lives than those who don't.

Yet the women also represent a mere 20 percent of patients nationwide who take advantage of cardiac rehab services. What accounts for the striking inconsistency, and what can be done to improve the sobering numbers?

UNDERUSED LIFE-SAVER

Cardiac rehab, as defined by the American Heart Association (AHA), is a supervised program to help patients recover from heart attacks, heart surgery and minimally invasive procedures such as angioplasty. In addition to structured exercise programs, cardiac rehab involves a healthy dose of education to encourage lifestyle behaviors, reduce symptoms and lessen the risk of a future cardiac event.

The AHA identifies three categories of patients who can benefit from cardiac rehab--those who have sustained a heart attack, those who have undergone heart surgery such as a bypass, and people with identified risk factors such as coronary artery disease or angina.

While every case is unique, cardiac rehab typically progresses through three phases.

Phase I. Beginning immediately after a heart attack or heart procedure, phase I rehab continues throughout a patient's hospital stay. Early activity reduces blood clotting, improves respiration and lays the groundwork for healthy recovery. Vital signs are monitored and cardiologists oversee progress. Phase I is covered by most insurance programs, and patients receive daily therapy.

Phase II. The second phase of cardiac rehab is an outpatient service that starts after a patient leaves the hospital. It's usually a mixture of medically supervised exercises and education on lifestyle factors. Insurance coverage varies.

Many exercise programs are conducted in a group setting, 3 days a week. Patients are hemodynamically and EMG-monitored as they rotate through activities, from rowing machines to treadmills to mat-based exercise and walking routines. Phase II can last from a week to several months.

Phase III. Phase III cardiac rehab is a long-term maintenance program that should continue for the rest of the patient's life. Few insurance companies cover phase III, so most patients elect to continue rehab at home, or join a long-term cardiac rehab program offered through a hospital, private practice or home care service.

The basics of cardiac rehab haven't changed much since the 1970s. Cardiologists know that it works, and research continues to quantify the benefits to circulation, cholesterol and triglyceride profiles, work capacity, weight control and anxiety levels and, most notably, overall mortality.

For instance, a recently released study of more than 600,000 Medicare beneficiaries hospitalized for heart disease or bypass surgery observed that mortality was 21 percent to 34 percent lower among patients who received cardiac rehab. People who sustained a heart attack or a coronary bypass operation, even those with congestive heart failure, benefitted. Benefits were magnified in patients with other conditions such as diabetes. And more rehab seems to be better--the study found that patients who engaged in more than 24 sessions were an additional 19 percent less likely to die over 5 years. Results of the study appeared in the June 30, 2009 edition of the Journal of the American College of Cardiology.

"We've recognized for some time that cardiac rehabilitation is a cost-effective service that saves lives," says Jose Suaya, MD, PhD, MBA, MPH, lead author of the study and research associate at the Schneider Institutes for Health Policy at Brandeis University in Waltham, Mass. "Patients who use cardiac rehab live longer than those who do not use it, regardless of their clinical diagnosis, gender, race or socioeconomic background."

"This is a landmark study for the importance and efficacy of cardiac rehabilitation," says Murray Low, EdD, FAACVPR, president of the American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR). And the mortality benefit is similar to that found with medications such as statins, adds Low, the director of cardiac rehab at health facilities in New York and Connecticut.

But now comes the hard part, which is ensuring that the service is adequately reimbursed, establishing quality measures for referral patterns, getting more hospitals and medical centers to launch programs, and bringing up the historically dismal utilization rates among patients.