High-sensitivity cTnT implementation ups myocardial injury, infarction

Implementation of high-sensitivity cardiac troponin T (cTnT) is associated with a significant increase in myocardial injury and myocardial infarction (MI), especially in women and patients with type 2 MI, reveals a study. Regardless, overall resource use has not increased, except for angiography.

In addition, patients without cTnT increases have more emergency department (ED) discharges and fewer cardiac tests.

The investigators conducted an observational US cohort study of ED patients undergoing measurement of cTnT during the transition from 4th (preimplementation 12 March 2018 to 11 September 2018) to 5th generation cTnT (postimplementation 12 September 2018 to 11 March 2019). They evaluated diagnoses using the Fourth Universal Definition of Myocardial Infarction and assessed resources including length of stay, hospitalizations, and cardiac testing.

The study analysed 3,536 patients, including 2,069 and 2,491 ED encounters pre- and postimplementation, respectively. Use of 5th generation cTnT led to a rise in encounters with ≥1 cTnT >99th percentile compared with 4th generation cTnT (47 percent vs 15 percent; p<0.0001). Acute MI (8.1 percent vs 3.3 percent; p<0.0001) and myocardial injury (38 percent vs 11 percent) also increased.

Type 1 MIs increased (2.9 percent vs 1.7 percent; p=0.0097) as well, but the overall MI surge was caused by more type 2 MIs (5.2 percent vs 1.6 percent; p<0.0001).

Men were more likely to have MI using 4th generation cTnT than women (4.4 percent vs 2.3 percent; p=0.008) but not 5th generation cTnT (8.5 precent vs 7.7 percent; p=0.46).

Of note, there was a reduction in overall length of stay and stress testing and an increase in angiography (p_all<0.05). Moreover, patients without cTnT increases recorded more ED discharges and a decrease in length of stay, echocardiography, and stress tests (p_all<0.05).