The correlation between high-sensitivity troponin-T and cell-free cardiac DNA in the blood of patients undergoing noncardiac, predominantly vascular surgery

Objective To present a novel method that uses an epigenetic fingerprint to measure changes in plasma concentrations of cardiac-specific cell-free DNA (CS-cfDNA) as a marker of myocardial cell death. Methods This prospective, analytic, observational comparative study included patients with heart disease or multiple risk factors for heart disease undergoing major noncardiac, mostly vascular surgery, requiring an arterial-line, and at least 24 h hospitalization in the post anaesthesia care unit or critical care unit after surgery. Blood samples were collected at least four times per patient to measure troponin-T (via high-sensitivity troponin-T test) and CS-cfDNA pre- and postoperatively. Results A total of 117 patients were included (group 1, 77 patients [66%] with low preoperative and postoperative troponin-T; group 2, 18 patients [15%] with low preoperative but increased postoperative troponin-T; group 3, 16 patients [14%] with high troponin-T both preoperatively and postoperatively; and group 4, six patients [5%] with elevated preoperative troponin-T that decreased postoperatively). The increase in CS-cfDNA after surgery was statistically significant only in group 2, which correlated with an increase in troponin-T in the same group. Conclusions CS-cfDNA increased early postoperatively, particularly in patients with silent postoperative troponin elevation, and was correlated with an increase in troponin-T. These results may suggest that, in the subgroup of patients with postoperative elevated troponin, cardiomyocyte death indeed occurred

Cardiac troponin after major vascular surgery: the role of perioperative ischemia, preoperative thallium scanning, and coronary revascularization

We sought to determine the role of preoperative predictors, particularly ischemia, on preoperative thallium scanning (PTS) and coronary revascularization on low-level and conventional troponin elevations after major vascular surgery. Postoperative cardiac troponin (cTn) elevations have recently been shown to predict both short- and long-term mortality after vascular surgery. The perioperative data, including PTS and subsequent coronary revascularization, continuous perioperative 12-lead ST-segment trend monitoring, cTn-I and/or cTn-T, and creatine kinase-MB fraction in the first three postoperative days, were prospectively collected in 501 consecutive elective major vascular procedures. Moderate to severe inducible ischemia on PTS was associated with a 49.0% incidence of low-level (cTn-I >0.6 and/or cTn-T >0.03 ng/ml) and 22.4% conventional (cTn-I >1.5 and/or cTn-T >0.1 ng/ml) troponin elevation. In contrast, patients with preoperative coronary revascularization had 23.4% and 6.4% low-level and conventional troponin elevations, respectively, similar to patients without ischemia on PTS. By multivariate logistic regression, ischemia on PTS was the most important predictor of both low-level and conventional troponin elevations (adjusted odds ratios [ORs] 2.5 and 2.7, p = 0.02 and 0.04, respectively), whereas preoperative coronary revascularization predicted less troponin elevations (adjusted ORs 0.35 and 0.16, p = 0.045 and 0.022, respectively). Postoperative ischemia (>10 min), the more so prolonged (>30 min) ischemia was the only independent predictor of troponin elevation if added with the preoperative predictors to the multivariate analysis (ORs 15.8 and 22.8, respectively, p < 0.001). Troponin elevations occur frequently after vascular surgery. They are strongly associated with postoperative ischemia, predicted by inducible ischemia on PTS, and reduced by preoperative coronary revascularization