Below Radar

With 900 000 procedures performed annually in North America, percutaneous coronary intervention has dramatically altered the landscape of cardiology since its inception in 1977. Despite procedural success rates now exceeding 90%, biomarker rise indicating myonecrosis has been reported after up to 30% of otherwise successful procedures.1 Most agree with the Joint European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction recommendation that the same biochemical marker cutoffs be applied regardless of the clinical circumstances.2 However, available data suggest that mild periprocedural marker rise may not confer substantial risk in an otherwise successful procedure. Several reports have identified non–Q-wave infarctions with creatine kinase (CK)–MB elevations 3 to 5 times the upper limit of normal as having clinical significance, whereas others suggest that increased risk may become apparent only for large non–Q-wave (CK-MB rise 5 to 8 times the upper limit of normal) and Q-wave myocardial infarctions,3 which are largely related to procedural complications.4 Troponin T and I elevation occurs more frequently than CK-MB increase after percutaneous coronary intervention and does not appear to have prognostic value unless a marked increase ( 5 times the upper limit of normal) occurs.5 A notable exception comes from saphenous vein grafts in which even mild CK-MB rise after successful intervention predicts mortality.6