The impact of drop-out in cardiac rehabilitation on outcome among coronary artery disease patients

Background The effect of adherence to cardiac rehabilitation (CR) on outcome is not clear. Therefore, we aimed to assess the impact of drop-out for non-medical reasons of CR on event-free survival in coronary artery disease (CAD). Methods A total of 876 patients who attended CR after acute coronary syndrome (ACS), percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) were included. Drop-out was defined as attending ≤50% of the training sessions. A combined endpoint of all-cause mortality and rehospitalization for a cardiovascular event was used to specify event-free survival. Differences in clinical characteristics were assessed and parameters with p < 0.10 were entered in a multiple Cox regression analysis. Results A total of 15% died or had a cardiovascular event during a median follow-up period of 33 months (interquartile range 24, 51). Overall, 17% dropped out before finishing half of the program. Patients who withdrew prematurely had a risk twice as high for a cardiovascular event or death (hazard ratio 1.92, 95% confidence interval 1.28-2.90) than those who attended more than half of the sessions. Both ACS (2.36, 1.47-3.58) and PCI (2.20, 1.22-3.96), as primary indicators for CR, were associated with an adverse outcome and also a prior history of chronic heart failure (CHF) remained negatively associated with event-free survival (3.67, 1.24-10.91). Finally, the presence of hyperlipidemia was independently related to a worse outcome (1.48, 1.02-2.16). Conclusions Drop-out for non-medical reasons was independently associated with a negative outcome in CAD. Therefore, underlying factors for drop-out should gain more attention in future research and should be taken into account when organizing CR.