Elecsys troponin t hs

TNFα, MPO and hsCRP were measured by ELISA kits (TNF-apha Human, High sensitivity; Myeloperoxidase Human Instant and CRP Human, produced by Invitrogen by Thermo Fisher Scientific, MA, USA). hsTnT, BNP and NT-pro BNP were assayed by ECLIA methodology using commercial kits (Elecsys Troponin T hs, Elecsys BNP, Elecsys proBNP II, respectively) from Roche Diagnostics S.p.A., Milan (Italy) on the COBAS analyser e411. Mid-regional proADM and NT-PRO3 by ELISA kits (Human MR-ProADM and Human Procollagen III N-Terminal Propeptide) produced by MYBIOSOURCE, CA (USA).

COVID-19 was confirmed by positive RT-PCR for SARS-CoV-2 from throat swabs, sputum or endotracheal suction. Presence of myocardial injury was defined by elevated hsTNT levels (Elecsys Troponin T hs by Roche Diagnostics GmbH, Vienna, Austria) above the 99th percentile upper reference limit (0.014 ng/ml). Acute respiratory distress syndrome (ARDS) was diagnosed according to the Berlin definition and Horovitz Index served for differentiation of severity as described before [5 (link)]. Pre-existing cardiovascular disease (CVD) comprised coronary artery disease, atrial fibrillation or known heart failure.
Systolic LV dysfunction (LVD_sys) was indicated if 3D-LVEF was below 50% [9 (link), 10 (link)], or if LV global longitudinal strain (LV-GLS) was above -16% [11 (link)]. Diastolic LV dysfunction (LVD_dia) was present if three out of the following six parameters were found: Mitral peak E velocity ≤ 50 cm/s, E/A ratio ≤ 0.8, average E/e′ > 14, septal e′ velocity < 7 cm/s or lateral e′ velocity < 10 cm/s, tricuspid regurgitation (TR) velocity > 280 cm/s or left atrial volume (3D-LAV) index > 34 ml/m² [12 (link)]. Systolic right ventricular (RV) dysfunction (RVD_sys) was defined as 3D-RVEF below 45% [13 (link)] or impaired RV free wall strain (RV-FWS) above -20% [9 (link)].

High-sensitive cardiac troponin-T (hs-cTnT) was measured at baseline and 24 h after PCI. Hs-cTnT levels were measured using an electrochemiluminescence immunoassay (Elecsys Troponin T hs; Roche Diagnostics GmbH, Mannheim, Germany). This method has a measuring range of 0.003–10 ng/mL and a 99th percentile upper reference limit (URL) of 0.014 ng/mL with a coefficient variation of < 10% at 0.013 ng/mL.
pMI was defined as an absolute elevation in hs-cTnT values of  > 5 × 99th percentile URL in patients undergoing PCI, according to the fourth universal definition of myocardial infarction. If the baseline hs-cTnT values are increasing, then an increase of > 20% is required for the diagnosis of pMI [21 (link)].