Abstract 13932: Quantification of Infarct Size by Measuring Troponin Release is not Accurate in Presence of Left Ventricular Hypertrophy: Experimental Study and Clinical Validation Using Cardiac Magnetic Resonance
Introduction: Infarct size estimation using biomarkers (creatine kinase (CK) and troponin (Tn)) is daily practice and an endpoint in many experimental and clinical studies. We recently described for the first time in a retrospective study that the peak of TnI could overestimate infarct size in presence of left ventricular hypertrophy (LVH).
The purpose of the present work is to provide prospective evidence in this regard.
Hypothesis: Peak and area under the curve (AUC) of TnI significantly overestimate infarct size in presence of LVH.
Methods: Pigs (n=10) with previously induced LVH by aortic banding underwent myocardial infarction. Non-LVH pigs (n=8) underwent same myocardial infarction and served as controls. Two 3-Tesla Magnetic Resonance (MR) studies were performed before and 7 days after infarction. Total CK and TnI systemic values were serially measured.
Clinical validation was done in a cohort of 140 patients with anterior STEMI prospectively recruited who underwent MR 7 days after infarction. CK and TnI systemic values were serially measured.
Multiple lineal regression analysis was used to study the role of LVH in the association between CK and TnI values and infarct size on MR.
Results: In the experimental study, six animals died before protocol completion. Both in the experimental and clinical studies, LVH was associated with a significant increase in peak and AUC of TnI (panels A and B shows the pig and clinical data respectively). These results were observed both when LVH was categorized: LVH yes/no (pig data, panel A) or tertiles (clinical data, panel B) and when indexed LV mass was evaluated as a continuous variable (panel C). No significant differences were found in peak/AUC of total CK between LVH vs. no-LVH neither in the experimental nor the clinical study.
Conclusions: Both peak and AUC of TnI significantly overestimate infarct size in presence of LVH. LVH (presence and degree) should be taken into consideration when infarct size is estimated by troponin release.
- © 2013 by American Heart Association, Inc.