How "Fragile" Is the Debate Against Coronary Artery Bypass Grafting?

Percutaneous coronary intervention (PCI) versus coronary artery bypass grafting (CABG) for coronary revascularization is a debated topic. There have been randomized controlled trials (RCTs) comparing both modalities. The fragility index (FI) is a way of measuring the robustness of an RCT. FI is the minimum number of patients whose status would have to change from a nonevent to event to convert a statistically significant result to a nonsignificant result. Our goal was to assess the robustness of current RCTs regarding the PCI versus CABG debate.

PubMed was queried using the following search terms "PCI," "CABG," and "RCT" with a filter applied for the last 20 y. These results were then examined for RCTs with significant dichotomous outcomes. Of those selected studies, an FI was calculated for respectively significant primary outcomes. The FI were then averaged for primary outcomes.

A total of 314 trials were identified from our initial PubMed query. After exclusion criteria, a total of 9 trials met inclusion criteria. On average the FI for major adverse cardiovascular or cerebrovascular event outcome in support of CABG was 18. There were no trials found significantly supporting PCI over CABG in the primary outcome of major adverse cardiac events.

The current state of literature demonstrates that studies in support of CABG are more robust. Although there are some RCTs suggesting no difference compared to CABG to PCI in their primary outcome, they are not as robust as those in support of CABG. The superior method for revascularization still remains multifactorial and patient-dependent.