Post-STEMI cardiac troponin I ‘provides useful prognostic information’
MedWire News: Measuring cardiac troponin I (cTnI) levels after primary percutaneous coronary intervention (PCI) offers valuable information on the patient's future left ventricular (LV) function, an international team has shown.
Writing in the journal Heart, Jonas Hallén (Oslo University Hospital, Norway) and team say that a single cTnI value measured early after ST-segment elevation myocardial infarction (STEMI) "can potentially facilitate identification of individuals at particularly high risk who might benefit from closer follow-up and targeted treatment."
Hallén's team performed a post-hoc analysis of data from the Efficacy of FX06 in the Prevention of Myocardial Reperfusion Injury (FIRE) trial. This was a randomized study of an experimental anti-inflammatory peptide, FX06, in 132 STEMI patients who underwent primary PCI within 6 hours of symptom onset.
As part of the trial protocol patients had cTnI levels measured at 24 and 48 hours and underwent cardiac magnetic resonance imaging at 5 days and 4 months.
After adjusting for LV parameters at 5 days post-STEMI, cTnI levels at either 24 or 48 hours were strong, independent predictors of changes in LV ejection fraction (EF), end-diastolic volume index, and end-systolic volume index during the follow-up period (all p<0.001), the researchers report.
Furthermore, in logistic regression analysis, cTnI levels at either 24 or 48 hours were better able to predict a reduced LVEF at 4 months than was LVEF at 5 days.
"For prediction of chronic LVEF <40%, addition of cTnI at 24 or 48 hours to early LVEF significantly increased the global fit of the model," write Hallén and co-authors.
They conclude that, in this contemporary cohort of STEMI patients, a single measurement of cTnI provides useful prognostic information on changes in LV function and volumes during the first 4 months after the acute event.
"As cTnI release reflects myocardial necrosis, our data are consistent with the concept that after myocardial infarction, the degree of functional recovery and the accompanying adaptive volumetric changes occur in response to the amount of myocardial destruction," they write.
"These observations suggest that cTnI measurements may facilitate risk stratification of patients during the critical early stage after STEMI."
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By Joanna Lyford