Background: The effect of adherence to cardiac rehabilitation (CR) on outcome is not entirely clear.

Purpose: Therefore, we aimed to assess the impact of premature withdrawal of CR on outcome in coronary artery disease (CAD) patients.

Methods: 1024 CAD patients who entered CR between September 2007 and January 2013 were prospectively enrolled in the study. One-hundred patients who dropped out for medical reasons were excluded, resulting in 924 patients with acute coronary syndrome (n=388), elective percutaneous coronary intervention (n=129) or coronary artery bypass graft (n=407). Drop-out was defined as attending ≤50% of the training program, which has a maximum of 45 sessions. Differences in clinical characteristics and a combined end-point of all-cause mortality and rehospitalisation for a coronary event, cerebrovascular accident or heart failure, were assessed according to drop-out.

Results: Patients attended 36±12 training sessions on average, with 18% dropping out in the first half of the program. A median follow-up period of 33 months (interquartile range [24,51]) was completed after start of CR, which was equal between both groups of patients. Also a similar demographic and clinical profile was observed in both groups with a comparable age, gender distribution, left ventricular function and baseline exercise capacity. However, patients who withdrew prematurely from CR, had more comorbidities such as chronic obstructive pulmonary disease (p=0.049) and peripheral arterial disease (p=0.011) and were more frequently smokers at start of CR (p=0.025). These patients were also more frequently singles (p=0.07), more dependent on others to get to CR (p=0.026) and tended to report more anxiety-related problems on the Hospital Anxiety and Depression Scale (p=0.081) at start of CR. Furthermore, two years after starting CR, patients who dropped out had a significantly higher event rate than their counterparts who attended the program for more than half of the sessions. (21% versus 12%, p=0.001).

Conclusion: Drop-out is associated with an adverse outcome in CAD patients, with a higher event rate for the combined end-point of mortality and rehospitalisation among those patients that withdrew prematurely from the CR program. Therefore, patients should be encouraged to sustain their program, in particular those with comorbidities and a vulnerable psychosocial background which seems to play a predisposing role in drop-out.