Lack of Change in the Incidence of Unstable Angina after Transition to High-Sensitivity Cardiac Troponin T.

OBJECTIVE

This study evaluated the impact of high-sensitivity cardiac troponin T (hs-cTnT) implementation on the incidence and cardiac evaluations of patients with unstable angina.

METHODS

This was a retrospective U.S. cohort study of emergency department patients evaluated with cardiac troponin (cTn) measurements during the transition from 4th-generation cTnT (6 months pre-implementation) to 5th-generation hs-cTnT assay (6 months postimplementation).

RESULTS

Only 39 patients were diagnosed with unstable angina; 18 with 4th-generation cTnT and 21 with 5th-generation hs-cTnT. With 4th-generation cTnT assay, almost all (94.4%) had values < 99th upper reference limit, whereas 33.3% had at least one value > 99th (mean = 25ng/L and peak = 26 ng/L) with hs-cTnT assay. The latter had underlying structural heart disease. There were no significant differences in cardiac evaluations with echocardiography, stress testing, or invasive coronary angiography between the two groups.

CONCLUSIONS

The incidence of unstable angina did not change with the transition to 5th-generation hs-cTnT assay. However, stable hs-cTnT increases were more common, likely due to underlying structural heart disease. There were no changes in the frequency of cardiac evaluations.