Cardiac Rehabilitation Effectiveness for Coronary Artery Disease by Clinical Era: Trial Sequential Analysis

Cardiac rehabilitation (CR) is an outpatient model of care for the secondary prevention of cardiovascular disease, which is widely and strongly recommended in international clinical guidelines. The latest update of the Cochrane systematic review on CR for patients with coronary artery disease1 found that CR is effective in preventing cardiovascular death and hospital admissions, but not all-cause mortality, reinfarctions and other complications, as reported in the previous update. This could be due to the inclusion of more recent trials. Thanks to advances in medicine, patients now have access to acute revascularization treatments such as thrombolysis and angioplasty, and therefore achieve better outcomes, such that some have hypothesized that CR may have less impact in the current clinical era2. Although the Cochrane review included a meta-regression which showed no impact of the publication year on the effectiveness,1 some others meta-analyses in the field that have included only recent trials,2,3 have contradicted this finding. In this context, we conducted a secondary analysis of these trials with the aim of examining whether there is sufficient data to determine effectiveness of CR on all-cause and cardiovascular mortality as well as hospitalization, and to test effectiveness over time, using trial sequential analysis (TSA) for the first time. With sequential analysis, it is possible to determine the need for more trials or whether the results are conclusive.4 Such analysis allows the effect to be observed as the participants in the primary studies accumulate even if the optimal sample size has not been reached, adjusting the threshold of statistical significance as the sample size is accumulated. 5