Perspective:

This is a post hoc analysis of the main MATRIX trial that did not show benefit of bivalirudin over heparin with or without post-PCI bivalirudin infusion. All results from this analysis should be interpreted with reserve, and as the authors state, ‘are hypothesis generating.’ Multiple comparisons are reported. The main objective was to see if a prolonged PCI infusion of bivalirudin at full dose or half dose impacted outcomes based on type of ACS. Findings suggest that type of ACS did not modify the absence of benefit for post-PCI bivalirudin infusion versus no infusion. Findings do suggest (with multiple caveats) that when bivalirudin is continued at full dose post-PCI, there are beneficial effects with respect to ischemic and bleeding endpoints. Results need to be interpreted with caution in the context of the main analysis being negative. Determination of low- or full-dose bivalirudin infusion was left at the discretion of the operator and may have resulted in selection bias, which cannot be adjusted for. In addition, the presence of less bleeding with full- compared to low-dose bivalirudin post-PCI infusion is counterintuitive and suggests persistent confounding factors.