Quartiles of Peak Troponin Are Associated with Long‐term Risk of Death in Type 1 and STEMI, but Not in Type 2 or NSTEMI Patients

Abstract

Background: The prognostic value of peak cardiac troponin (cTn) in different types of acute myocardial infarction (AMI) under the universal clinical classification is unknown. Hypothesis: We tested the hypothesis that the prognostic value of cTn varies with its peak level and type of AMI. Methods: We studied 345 consecutive patients with AMI with mean follow-up of 30.6 months according to quartiles of peak cTn level (QPTL) and the type of AMI. The study outcomes were the major adverse cardiovascular events (MACE; composite of all causes of mortality and recurrent AMI) and the individual components of MACE. Results: The study included patients with AMI Type 1 (n = 276), type 2 (n = 54), ST-segment elevation myocardial infarction (STEMI; n = 159), and non-ST-segment elevation myocardial infarction (NSTEMI; n = 186). Overall, peak cTn level was an independent predictor of MACE (hazard ratio [HR]: 1.001, 95% confidence interval [CI]: 1.000-1.003, P = 0.01) and death (HR: 1.002, 95% CI: 1.001-1.004, P = 0.003), but not of recurrent AMI. The highest risk of MACE and death was in the highest QPTL (61.6%, P = .016 and 66.3%, P = 0.021, respectively) while the highest risk of recurrent AMI was in the lowest QPTL (83.7%, P = 0.04). Quartiles of peak cTn level were significantly associated with increased risk of MACE and death in patients with Type 1 (all P = 0.01) and STEMI (P = 0.01 and P = 0.02, respectively), but no association existed in type 2 or NSTEMI patients. Conclusions: Overall, peak cTn predicts the risk of MACE and death but not the risk of AMI. While in Type 1 and STEMI patients, QPTL are associated with risk of MACE and death, no association exists in type 2 or NSTEMI patients. IntroductionThe universal clinical classification (UCC) of acute myocardial infarction (AMI) recommends cardiac troponin as the preferred biomarker of cardiomyocyte necrosis.

Cardiac Troponin Rapid Rule-Out Protocols in Suspected Acute Coronary Syndrome: The Faster the Better or a Loss of Information regarding Outcome and Adjunctive Therapy?

“…As this was a single-center study including a small sample size and event rate in contrast to the complex Cox regression equation used, there may have been many potential confounding factors that could account for the results conflicting with those of previous reports [18,19,20]. Notwithstanding, the study sheds an important light on an old-fashioned but certainly important issue: the importance of examining cTn levels even hours or days after diagnosis as a tool to further risk-stratify NSTEMI patients far beyond the initial diagnostic protocols, which are, controversially, getting progressively faster.…”

Cardiac troponins and mortality in type 1 and 2 myocardial infarction

“…One of the studies originally identified by our search criteria was excluded from pooled analysis because no indication was provided about the type of cardiac troponin that was measured [22]. However, the results deserve a brief mention.…”

Predictors of Peak Troponin Level in Acute Coronary Syndromes: Prior Aspirin Use and SYNTAX Score

“…This is likely due to the transmural myocardial injury that occurs in the setting of STEMI. 19 Patients with STEMI have a persistent and complete occlusion of an epicardial artery putting a large myocardial territory at risk of ischemia. 4 In contrast, NSTEMI and UA results from varying degree of coronary obstruction, but without a complete occlusion of the vessel.…”

“…The Siemens Immulite 1000 (Erlangen, Germany) troponin I (99th percentile: 0.19 µg/L, CV at 99th percentile: 11, CV at 10th percentile: 0.22, with reference range being 0.01-0. 19) and Siemens ADVIA Centaur BNP (reference < 100 ng/L) assays were used. The daily use of aspirin, statin, β-blockers, calcium channel blockers, and angiotensin converting enzyme inhibitors (ACE-I) or angiotensin receptor blockers (ARB) previous to hospitalization was noted for each patient.…”