Prognostic value of procedure-related myocardial infarction according to the universal definition of myocardial infarction in saphenous vein graft interventions

Background: In the recently published universal definition of myocardial infarction (MI), a troponin elevation above 3× above the 99th percentile of normal after percutaneous coronary intervention (PCI) is a procedure-related (type 4a) MI. Although troponin rise is common after saphenous vein graft (SVG) PCI, its prognostic value remains undetermined. We aimed to investigate the prognostic value of the universal definition of PCI-related MI in SVG interventions. Methods: A cohort of 589 unselected consecutives patients with normal preprocedural troponin Ic undergoing isolated SVG PCI with drug-eluting stent implantation was included. Patients were divided into 2 groups according to the peak troponin value post PCI: those with MI defined as a peak troponin value above 3× the 99th percentile of normal post-PCI (MI group, n = 166) and those without (no MI group, n = 423). The primary end point was the rate of major adverse cardiac events including death, MI, and target vessel revascularization at 1-year follow-up. Results: Baseline characteristics were similar between the 2 groups. In the MI group, patients had more complex angiographic features (type C lesions: 44.7 vs 34.8%; P = .006). The rate of direct stenting and distal protection use were similar in the 2 groups (MI vs no MI: 29.2 vs 28.7%; P = .9 and 32 vs 37.5%; P = .24, respectively). Patients in the MI group had a worse inhospital course but a similar 1-year rate of major adverse cardiac events (22.3 vs 19.1%; P = .39). Conclusion: Procedure-related MI after PCI, as defined by the universal definition, is associated with an adverse inhospital course but may not predict long-term outcome in SVG PCI.