Guimaraes PO, et al. - The provoking factors, cardiac biomarker profiles, treatment patterns, and clinical outcomes of patients with type 2 myocardial infarctions (MIs) were explored in this trial. As per observations, prevalence of type 2 MIs was more in the first month after acute coronary syndromes (ACS). Furthermore, type 2 MIs were characterized by the presence of triggers and infrequent use of an invasive strategy and were related to a high mortality risk.

Methods

• The Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome (TRACER) trial included patients with non-ST-segment elevation acute coronary syndromes.
• During trial follow-up, MI events were adjudicated by an independent clinical events classification committee (CEC) and were divided according to the Third Universal Definition of MI.
• Researchers performed a retrospective chart abstraction to collect details on the type 2 MIs and for this purpose, they used available source documents retrieved as part of the CEC process.
• They also used Cox regression models to explore the link between MI type (type 1 or type 2) and all-cause death.

Results

• Overall, it was demonstrated in findings that 10.3% (n = 1327) of TRACER participants had a total of 1579 adjudicated MIs during a median follow-up of 502 days (interquartile range [IQR] 349–667).
• Data also showed that out of all MIs, 5.2% (n = 82) were CEC-adjudicated type 2 MIs, occurring in 76 patients.
• Researchers observed that the incidence of type 2 MI was higher in the first month following randomization, after which the distribution became more scattered.
• Tachyarrhythmias (38.2%), anemia/bleeding (21.1%), hypotension/shock (14.5%), and hypertensive emergencies (11.8%) were identified as the most frequent potential provoking factors for type 2 MIs.
• Overall, findings revealed that 36.3% had a troponin increase >10× the upper limit of normal.
• During hospitalizations ascribed to type 2 MIs, coronary angiography was performed in 22.4% (n = 17) of patients.
• It was also revealed that following type 2 MI, the hazard of death was numerically higher (vs. no MI, adj. HR 8.25, 95% CI 4.57–14.92; P < .0001) than that of type 1 MI (vs. no MI, adj. HR 5.71, 95% CI 4.62–7.06; P < .0001).