Hemorrhagic myocardial infarction (MI) can be diagnosed by a blood biomarker, which could predict adverse risk of acute outcomes, such as heart failure and sudden death, according to a new study. Findings presented Tuesday at Cardiovascular Research Technologies (CRT) 2024 in Washington, D.C., raise hopes of this biomarker’s future use in clinical trials to mitigate myocardial hemorrhage (MH) and improve survival post-ST-elevation myocardial infarction (STEMI). “In an acute clinical setting patient stability, arrhythmias, discomfort, limitations in access to advanced magnetic resonance imaging (MRI) come into play,” said Rohan Dharmakumar, PhD, principal study investigator, and the Charles Fisch Professor of Cardiology at the Krannert Cardiovascular Research Center in Indiana. “Troponin levels after reperfusion therapy can supplement or provide a highly reliable alternative to a cardiac MRI, for diagnosing hemorrhagic MI.” Research findings Study results presented by Ankur Kalra, MD, at CRT 2024 found sensitivity, specificity, and area under the curve (AUC) for the troponin-based biomarker (cut-off: 111 ng/ml) for hemorrhagic MI were all >0.8. Peak troponin concentration was correlated with myocardial hemorrhage (MH) volume (R2=0.89, p<0.001), said Kalra, an interventional cardiologist at Franciscan Health in Mishawaka, Indiana. Acute outcomes in hemorrhagic MI (n=1,323) showed increased odds of in-hospital mortality (adjusted odds ratio [adj-OR]: 2.8; 95% confidence interval [CI]: 2.1-3.7; AUC=0.75) and 30-day mortality (adj-OR: 2.9; 95% CI: 2.2-3.7; AUC=0.74). Further findings revealed 30-day readmission rates (adj-OR: 1.5; 95% CI: 1.2-1.9; AUC=0.65), and 30-day acute heart failure (HF) (adj-OR: 2.6; 95% CI:1.7-4.1; AUC=0.75); p<0.0001). “The post-PCI troponin levels can enable medical centers without cardiac magnetic resonance imaging (MRI) the ability to diagnose hemorrhagic MI soon after percutaneous coronary intervention (PCI),” said Keyur Vora, MD, lead study clinical investigator and assistant research professor of medicine at the Indiana University School of Medicine. Methodology In the prospective trial of STEMI patients (n=201) undergoing PCI, a troponin-based test was developed and validated against T2* cardiovascular magnetic resonance to derive a blood marker for hemorrhagic MI. Based on this test, a multisite cohort of reperfused STEMI patients (n=6180), dichotomized for MH status, was used to predict primary acute outcomes (mortality, readmission, and acute HF). The prospective clinical trial comprised of 6180 reperfused STEMI patients recruited into discovery and validation arms. The discovery arm used retrospective identification of troponin thresholds for detection of patients with intramyocardial hemorrhage juxtaposed against cardiac MRI findings. The validation arm carried out prospective testing on patients of the reproducibility of thresholds confirmed by cardiac MRI. A retrospective analysis of clinical outcomes was performed on reperfused STEMI patients from seven hospitals in a single health system using hourly troponin thresholds derived from hemorrhagic myocardial infarction detection by biomarkers (MIRON-TROP). Hemorrhagic MI diagnostics A prospective multicenter observational study was then carried out, in which 154 patients made up the discovery cohort to predict primary acute outcomes (mortality, readmission, acute HF). Here, troponin was obtained upon arrival (0 hour), and then post-reperfusion every hour up to 12 hours, and then at 16, 20, 24 and 48 hours. A cardiac MRI was performed 3 days post-PCI. In the validation cohort, 53 patients were enrolled, with identical sampling time points as the discovery cohort. The thresholds and classified patients were categorized into hemorrhagic vs non-hemorrhagic, and a cardiac MRI was performed. The results were then matched to assess concordance between troponin-based and MRI-based diagnosis of hemorrhagic MI. Based on the hourly thresholds identified from MIRON-TROP, the research team performed a retrospective analysis categorizing patients into hemorrhagic vs. non-hemorrhagic STEMI. They then examined outcomes based on hemorrhagic vs., non-hemorrhagic status adjusting for other covariates. The study’s primary outcome was defined as mortality (in-hospital/30-day) and rehospitalization. Photo Credit: Jason Wermers/CRTonline.org Photo Caption: Ankur Kalra, MD, presents results form a study concerning a blood biomarker diagnosis of hemorrhagic myocardial infarction Tuesday at CRT 2024 in Washington, D.C.