Long-term prognostic value of asymptomatic cardiac troponin T elevations in patients after major vascular surgery

Background. Cardiac troponin T (cTnT) is a sensitive and specific marker for myocardial injury, but elevations of cTnT without clinical evidence of ischemia and persistent or new electrocardiographic (ECG) abnormalities are common in patients undergoing major vascular surgery. We explored the long-term prognostic value of cTnT levels in these patients. Methods. A follow-up study was conducted between 1996-2000 in 393 patients who underwent successful aortic or infrainguinal vascular surgery and routine sampling of cTnT. Patients were followed until May 2003 (median of 4 years [25th-75th percentile,, 2.8-5.3 years]). Total creatine kinase (CK), CK-MB, and cTnT were routinely screened in all patients, and included sampling after surgery and the mornings of postoperative days 2, 3 and 7. Electrocardiograms were also routinely evaluated for sign of ischemia. An elevated cTnT was defined as serum concentrations greater than or equal to0.1 ng/ml in any of these samples. All-cause mortality was evaluated during long-term follow-up. Results. Eighty patients (20%) had late death. The incidence of all-cause mortality (41% vs. 17%; p < 0.001) was significantly higher in patients with an elevated cTnT level compared to patients with normal cTnT. After adjustment for baseline clinical characteristics, the association between an elevated cTnT level and increased incidence of all-cause mortality (adjusted hazard ratio,. 1.9; 95% Cl, 1.1-3.1) persisted. Elevated cTnT had significant prognostic value in patients with and without renal dysfunction, abnormal levels of CK-MB, and in patients with transient ECG abnormalities. Conclusions. Elevated cTnT levels are associated with an increased incidence of all-cause mortality in patients undergoing major vascular surgery.