Cardiac rehabilitation: Even minor fitness improvements are associated with decrease in mortality, especially in the least fit

"There are benefits to cardiac rehabilitation, regardless of how fit -- or unfit -- you are," says Dr. Martin, a cardiac surgery resident and PhD candidate at the University of Calgary's Libin Cardiovascular Institute. "Patients who take responsibility for their own health and make improvements in fitness can keep themselves alive longer."

Interestingly, the greatest health benefits were derived by those who were least fit to begin with. "For them, even improving fitness a little bit had a major impact," says Dr. Martin. "You don't need to be in good physical condition to reap the benefits of cardiac rehab. In fact, the lower the level of fitness the more valuable cardiac rehab may be."

All over the country, people with heart disease are offered cardiac rehab, a program of exercise, education and counseling designed to help them recover after a heart attack, from a heart condition, or following heart surgery. Cardiac Rehab has been shown to improve outcomes in many clinical studies. Unfortunately patients are not always referred and do not always participate in such programs, says Dr. Martin.

Researchers at the Cardiac Wellness Institute of Calgary (CWIC) conducted a study of 2,867 people with coronary artery disease who participated in a cardiac rehab program between 1996 and 2010. Upon enrollment, they were measured for weight, waist circumference, blood pressure, blood glucose, and cholesterol.

Their fitness levels were tested on a treadmill. They were categorized into three groups: low fitness, moderate fitness, or high fitness based on standardized scores.

Then, they attended 12 weeks of rehabilitation, during which they took their prescribed medication and did regular aerobic, strength, and stretching exercises; they also attended education sessions to learn better nutrition and stress management -- "a full lifestyle revamp," says Dr. Martin. After 12 weeks, they were retested on the treadmill to determine fitness level. In addition, 1,696 of the people in the study returned for treadmill testing one year after starting the program.

Results showed the better a person's level of fitness, the lower the risk of death over the 15 years of the study. "We found that your fitness predicts how you do in the long term," says Dr. Martin. "If you are more fit, you are less likely to die."

"Over 1.3 million survivors are living with heart disease- and each of those life-changing events affects a network of family, friends, and coworkers," says Heart and Stroke Foundation spokesperson Dr. Beth Abramson "Cardiac rehabilitation supports patients to integrate lifestyle changes into their lives, with powerful results, yet it is underused. It is important that it is an essential part of the recovery process."

She recommends that if you or a family member are living with heart disease but have not been sent to cardiac rehab to talk to your doctor -- you may still be eligible to participate.

Dr. Martin agrees, adding that the next step is to increase attendance rates at cardiac rehabilitation programs. Right now, only about half of heart patients who are sent to rehab actually show up. The least likely to attend are the elderly and those who are sedentary, and they have the most to gain from it, she adds. "Now we can tell them they'll live longer. I like to tell patients our surgery takes four hours. You have the rest of your life to treat this disease."

Here are some of the important findings of the study:

• For every step you make in improving your fitness level, there is a 30% reduction in mortality.
• If you are out of shape, even small changes are helpful.
• The more you can improve fitness, the greater the benefit.