Regulatory perspective on embolic protection device approval for saphenous vein graft stenting with a single-arm trial using risk-adjusted prediction model.

The article by Coolong et al1 in this issue of Circulation identifies potential predictors of 30-day major adverse cardiac events (MACE) after saphenous vein graft (SVG) percutaneous coronary intervention (PCI) with embolic protection devices (EPDs). These predictors, angiographic estimates of plaque volume and SVG degeneration, were derived from patient-level data on 3958 patients enrolled in 6 clinical trials of SVG EPDs. As discussed in their article, the authors have incorporated these predictors into a model that seeks to accurately predict 30-day MACE rates for such devices. The authors make an intriguing proposal that their covariateadjusted, historically derived model could be used to construct an objective performance goal for the evaluation of novel EPDs. The implementation of such a model seems an attractive goal not only because of savings in time and cost for future clinical trials but also because of the potential to allow effective devices to reach patients more expeditiously. However, putting the model into practice will likely need some additional forethought and further collaborative effort to ensure that the effectiveness and safety of these devices are adequately evaluated. Although the investigators did not submit the actual predictive model within their article, we appreciate this opportunity to provide our insight into how such a model could potentially be integrated into future trials supporting regulatory approval.