Factors influencing the outcomes of patients with both coronary artery disease and diabetes enrolled in standard cardiac rehabilitation programs: a literature review.

Currently 23.5 million working-age adults 20 years or older have had a diagnosis of both coronary artery disease (CAD) and type 2 diabetes mellitus (T2DM), with estimates that an additional 9% of the total US population will have a diagnosis of this chronic disease combination by the year 2025. Current annual health care costs for this working-age population including medical costs, functional disability, work loss, and premature mortality currently exceed $620 billion. Prior research efforts have shown that 25% to 32% of patients requiring a coronary revascularization procedure have both CAD and T2DM. The primary intervention prescribed for these patients to regain functional ability after revascularization is enrollment in a standard outpatient cardiac rehabilitation (CR) program. These standard programs, ranging in duration from 6 to 12 weeks, have been shown to improve the physical function of CAD patients by up to 15%, but patients diagnosed with both chronic conditions of CAD and T2DM (T2DM+CAD) attending these same programs exhibit only an 8% improvement. Moreover, T2DM+CAD patients experience much lower rates of rehabilitation program appointment adherence as well as greater program attrition (T2DM+CAD: 45%-62% vs CAD: 92%). Current medical literature regarding the relationship between CAD, T2DM, and cardiac rehabilitation will be examined to identify specific factors that could influence the functional outcomes achieved by the T2DM+CAD population when enrolled in a standard CR program and help increase understanding of why the adherence and attrition differences exist.