The introduction of the new high-sensitivity cardiac troponin T (hs-cTnT) test was linked with an 11% decrease in reinfarctions but showed no evidence of improving survival in a large longitudinal cohort study.
Over an average of 3.9 years of follow-up, the adjusted risk of all-cause mortality was identical whether patients’ initial MI was diagnosed with the new troponin test or the conventional one, reported Maria Odqvist, MD, of South Alvsborg Hospital, Boras, Sweden, and her associates. “As hs-cTn assays become widely available and clinicians gain experience interpreting the results, more work is needed to enhance clinical reasoning and implementation to improve patient outcomes,” the researchers wrote in the.
High-sensitivity cardiac troponin T assays detect acute coronary syndrome more rapidly than their conventional predecessors. However, hs-cTnT’s higher sensitivity comes with lost specificity and hence has raised concerns about potentially wasting health care resources. Some clinicians have asked whether the new test is worthwhile and how to maximize its benefits.
The study, which included nearly 88,000 patients with initial MI from the Swedish National Patient Registry, spanned 2009-2013, when 73% of Swedish acute care hospitals transitioned from conventional troponin tests (cTn) to hs-cTnT. After adjustment for factors such as age, sex, location, chronic kidney disease, cardiovascular history, and prescriptions, Dr. Odqvist and her associates compared each test types’ risks of death, reinfarction, coronary angiography, and revascularization among patients diagnosed.
In all, 47,133 (54%) patients’ initial MI was diagnosed with cTn while 46% were diagnosed with hs-cTnT. Overall, the rate of MI rose by 5% during the 90 days after hospitals implemented hs-cTnT, compared with the 90 days before. But hospitals used varying hs-cTnT thresholds for MI, which might explain why some hospitals initially observed a marked initial decrease in MI while others saw a relatively large increase, the investigators wrote.
There were 15,766 reinfarctions over an average of 3.1 years of follow-up. Although there was no difference in all-cause mortality, risk of reinfarction was 11% lower among patients diagnosed using hs-cTnT, compared with those diagnosed by cTn.
At the hospital level, coronary angiography and revascularization became only slightly more common during the 3 months after hospitals switched to hs-cTnT, the researchers wrote. However, patients whose MIs were diagnosed with hs-cTnT were 16% more likely to undergo coronary angiography and 13% more likely to undergo revascularization within the next 30 days, compared with patients diagnosed with cTn. Patients diagnosed with hs-cTnT also were more likely to receive statins, but trends in other prescriptions did not change.
The Swedish Heart-Lung Foundation funded one investigator. Dr. Odqvist and one coinvestigator reported having no relevant conflicts of interest. Senior author Martin J. Holzmann, MD, PhD, disclosed ties to Actelion and Pfizer. Two other coinvestigators disclosed ties to Roche, Gilead, Janssen, Abbvie, CTI Bipharma, GlaxoSmithKline, Abbott Laboratories, and AstraZeneca, and Fiomi Diagnostics.
SOURCE: Odqvist M et al.