Biomarker profiles that differentiate type-1 and type 2 myocardial infarction.

Background: It is crucial to distinguish type-1 myocardial infarction (T1MI) from type-2 myocardial infarction (T2MI) at admission and during hospitalization to avoid unnecessary invasive exams and inappropriate admissions to the acute cardiac care unit.

Objectives: The purpose of the study was to define a simple profile derived from commonly used biomarkers to differentiate T1MI from T2MI.

Methods: We prospectively enrolled in an observational study 213 iconsecutive patients with a provisional diagnosis of non-ST-elevation acute myocardial infarction (NSTEMI) admitted to the Cardiology Department. A final diagnosis of T1MI, T2MI, and non-ischemic acute myocardial injury (NAMI) was given based on clinical and instrumental findings. We assessed high-sensitivity Troponin I (hs-cTnI), Creatine Kinase MB (CK-MB), C-reactive protein (CRP), procalcitonin (PCT), N-Terminal prohormone of brain natriuretic peptide (NTproBNP).

Results: A final diagnosis of T1MI was assigned to 77 patients, T2MI to 60 patients, and NAMI to 76 patients; mean age was not significantly different between groups (73 vs. 71 years), female were more prevalent in the T2MI/NAMI group (53 % vs. 34 %, p < 0.01). Hs-cTnI peak/upper limit of normal (ULN) (559 ± 770 vs. 286 ± 429; p = 0.04), hs-cTnI peak/CRP ratio (114 ± 337 vs. 83 ± 430; p < 0.001), hs-cTnI peak/PCT ratio (12,592 ± 21,467 vs. 4,609 ± 17,284; p < 0.001), and hs-cTnI peak/NTproBNP ratio (0.7 ± 1.6 vs. 0.3 ± 0.6; p < 0.01) differentiated T1MI from T2MI Hs-cTnI peak/ULN (559 ± 770 vs. 271 ± 412; p < 0.01), hs-cTnI peak/PCT ratio (12,592 ± 21,468 vs. 3,570 ± 12,469; p < 0.001), hs-cTnI peak/NTproBNP ratio (0.7 ± 1.6 vs. 0.3 ± 1.3; p < 0.001) and hs-cTnI peak/CRP (114 ± 337 vs. 48 ± 288; p < 0.001) differentiated T1MI from T2MI + NAMI. Hs-cTnI peak/PCT ratio was a predictor of T1MI, a multivariable logistic regression analysis (OR 1.03, 95 % CI 1.01-1.06, p < 0.05) with an accuracy of 0.704 (95 % CI 0.626-0.782, p < 0.001). No significant differences between T2MI and NAMI were detected.

Conclusions: Admission biomarker profile may differentiate T1MI from T2MI in patients admitted for NSTEMI.