Introduction Detectable levels of cardiac troponin-T by high sensitivity assay (hs-TnT) are elevated by both ischaemia and LV systolic dysfunction (LVSD) but it is unknown whether hs-TnT could be a useful biomarker to identify ischaemia either in the presence or the absence of LVSD.
Methods 500 consecutive patients undergoing a clinically indicated dipyridamole myocardial perfusion scintigraphy were studied. Those with impaired renal functions and history of atrial fibrillation or valvular disease were excluded. The troponin-T levels were measured in serum using a highly sensitive assay on an automated platform (Elecsys E170, Roche Diagnostics, lower limit of detection 3 ng/l). All scans were interpreted by a trained physician blinded to the biomarker data. Patients were divided into four groups based on reversible ischaemia and stress ejection fraction (EF) on gated SPECT imaging.
Results Data were available for 453 patients and 97/453 had a reversible ischaemic defect. hsTnT levels were significantly higher in patients with a reversible ischaemia (Median (IQR) 7.2 (3.3–10.9) vs 4.2 (3.0–7.5) pg/ml p<0.001) compared to those without. When analysed according to four groups based on LV function and reversible ischaemia, hsTnT levels were highest in patients with ischaemia and a low EF and lowest in patients with no ischaemia and normal EF (pTREND <0.001) as shown in the table 1. In a multivariate model which included age, gender, cardiovascular co-morbidities, eGFR, haemoglobin, BNP, and LV ejection fraction, hs-TnT remained an independent predictor of reversible perfusion defect (p=0.026).
Conclusions Baseline hs-cTnT levels are an independent predictor of reversible myocardial ischaemia and this is still the case in the presence of LVSD.⇓