Troponin Criteria for Myocardial Infarction After Percutaneous Coronary Intervention

Abstract

Troponin and CKMB elevations after percutaneous coronary intervention are associated with increased 1-year mortality rates, but thresholds for similar event frequency and mortality hazard are much higher for troponin than for CKMB.

Percutaneous Coronary Intervention Versus Optimal Medical Therapy for Prevention of Spontaneous Myocardial Infarction in Subjects With Stable Ischemic Heart Disease

“…In the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) registry of patients undergoing elective PCI, the rate of procedural MI was 7.2% when CK-MB was used but was almost 3 times higher when troponin was used (24.3%). 9 Other studies have similarly observed procedural MI rates as high as 48% when troponins were used 36 or when other definitions were used. 6 In addition to the frequency of occurrence of these events, the prognostic value of procedural MI itself has been questioned.…”

“…Although a few studies have shown a positive association of biomarker elevation with mortality, 8,9,36-40 others have shown a higher biomarker threshold (especially with the universal definition recommended for troponin) for such prognostic significance. 9,36 In the EVENT registry analysis, troponin levels >20 times the upper reference limit were equal to the prognostic importance of a 3-fold elevation in CK-MB. 9 Others have shown no association of biomarker (especially troponin) elevation with prognosis.…”

“…9,36 In the EVENT registry analysis, troponin levels >20 times the upper reference limit were equal to the prognostic importance of a 3-fold elevation in CK-MB. 9 Others have shown no association of biomarker (especially troponin) elevation with prognosis. 4,5 In an analysis of 3687 patients from the Prospective, Randomized Trial Comparing an Everolimus-Eluting Stent and a PaclitaxelEluting Stent in Patients with Coronary Artery Disease (SPIRIT IV), there was no association between procedural MI and mortality up to 2 years, even at high levels of CK-MB or troponin elevation (>10 times the upper reference limit).…”

Ticagrelor vs. Clopidogrel in Japanese, Korean and Taiwanese Patients With Acute Coronary Syndrome – Randomized, Double-Blind, Phase III PHILO Study –

“…17 During the analysis, however, it became clear that 62% of primary endpoint events during follow-up were associated with peri-procedural MI, in contrast to spontaneous MI. Although there is evidence to suggest that infarct size is predictive of subsequent cardiovascular (CV) death, 23 the majority of peri-procedural MI are small and are not associated with CV death. A post-hoc analysis was therefore undertaken using the composite endpoint of spontaneous MI, stroke, or CV death.…”

Torrent of Troponin

“…In the small gadolinium-enhanced Myocardial Injury following Coronary Artery Surgery versus Angioplasty (MICASA) study, categorization of a type 4a MI associated with a 3× elevation of CK-MB 5 required a troponin elevation of >40× 99th percentile. 11 In the Evaluation of Drug Eluting Stents and Ischemic Events (EVENT) registry, 12 troponin levels had to be elevated 20× ULN to be equivalent to the 1-year mortality (5.8%) associated with 3× elevation of CK-MB. In the Early Glycoprotein IIb/IIIa Inhibition in Non-ST-Segment Elevation Acute Coronary Syndrome (EARLY ACS) and Superior Yield of the New Strategy of Enoxaparin, Revascularization and Glycoprotein IIb/IIIa Inhibitors (SYNERGY) trials there was a significant increase in 1-year mortality with an increase of 10× URL of troponin (HR, 1.07; 95% confidence interval, 1.02-1.11; P=0.004).…”