Type 1 and 2 Myocardial Infarction and Myocardial Injury: Clinical Transition to High-Sensitivity Cardiac Troponin I. Am J Med 2017 Dec;130(12):1431-1439.e4
Date
07/26/2017Pubmed ID
28739197DOI
10.1016/j.amjmed.2017.05.049Scopus ID
2-s2.0-85027689487 (requires institutional sign-in at Scopus site) 96 CitationsAbstract
BACKGROUND: Studies addressing patients with type 2 myocardial infarction and myocardial injury, including the impact of using high-sensitivity (hs) cardiac troponin (cTn) assays on their incidence are needed.
METHODS: Ours is a prospective, observational US cohort study. Consecutive emergency department patients with serial cTnI measurements were studied. Outcomes included 180-day mortality and major adverse cardiac events, including 2-year follow-up for those with myonecrosis.
RESULTS: Among 1640 patients, using a contemporary cTnI assay, 30% (n = 497) had ≥1 cTnI >99th percentile, with 4.7% (n = 77), 8.5% (n = 140), and 17% (n = 280) classified as type 1 myocardial infarction, type 2 myocardial infarction, and myocardial injury, respectively. Compared with patients without myonecrosis, 180-day mortality was higher for type 2 myocardial infarction (4% vs 13%, P < .0001) (adjusted hazard ratio 2.7; 95% confidence interval, 1.6-4.8; P = .0005) and myocardial injury (4% vs 11%, P < .0001) (adjusted hazard ratio 1.8; 95% confidence interval, 1.1-3.0; P = .02), both with mortality >20% at 2 years. Predictors of 2-year mortality for type 2 myocardial infarction included age, congestive heart failure, and beta-blockers. Relative to the contemporary cTnI assay, hs-cTnI had less myonecrosis (30% vs 26%, P = .003) and acute myocardial infarction (13.2% vs 10.8%, P = .032), including fewer type 2 myocardial infarctions (8.5% vs 6.3, P = .01), with no difference in myocardial injury (17% vs 15%, P = .1).
CONCLUSIONS: cTnI increases are encountered in approximately a third of patients, the majority due to nonatherothrombotic conditions. Compared with patients without myonecrosis, type 2 myocardial infarction and myocardial injury have worse short-term outcomes, with mortality rates >20% at 2 years. hs-cTnI assay does not lead to more myocardial injury or infarction.
Author List
Sandoval Y, Smith SW, Sexter A, Thordsen SE, Bruen CA, Carlson MD, Dodd KW, Driver BE, Hu Y, Jacoby K, Johnson BK, Love SA, Moore JC, Schulz K, Scott NL, Apple FSAuthor
Sarah E. Thordsen MD Associate Professor in the Medicine department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
FemaleHeart Injuries
Humans
Incidence
Male
Middle Aged
Myocardial Infarction
Predictive Value of Tests
Prospective Studies
Sensitivity and Specificity
Troponin I