Abstract
The natural history and pathophysiological significance of tissue remodeling in the myocardial remote zone after acute ST-elevation myocardial infarction (STEMI) is incompletely understood. Extracellular volume (ECV) in myocardial regions of interest can now be measured with cardiac magnetic resonance imaging. Patients who sustained an acute STEMI were enrolled in a cohort study (BHF MR-MI [British Heart Foundation Magnetic Resonance Imaging in Acute ST-Segment Elevation Myocardial Infarction study]). Cardiac magnetic resonance was performed at 1.5 Tesla at 2 days and 6 months post STEMI. T1 modified Look-Locker inversion recovery mapping was performed before and 15 minutes after contrast (0.15 mmol/kg gadoterate meglumine) in 140 patients at 2 days post STEMI (mean age: 59 years, 76% male) and in 131 patients at 6 months post STEMI. Remote zone ECV was lower than infarct zone ECV (25.6±2.8% versus 51.4±8.9%; P<0.001). In multivariable regression, left ventricular ejection fraction was inversely associated with remote zone ECV (P<0.001), and diabetes mellitus was positively associated with remote zone ECV (P=0.010). No ST-segment resolution (P=0.034) and extent of ischemic area at risk (P<0.001) were multivariable associates of the change in remote zone ECV at 6 months (ΔECV). ΔECV was a multivariable associate of the change in left ventricular end-diastolic volume at 6 months (regression coefficient [95% confidence interval]: 1.43 (0.10-2.76); P=0.036). ΔECV is implicated in the pathophysiology of left ventricular remodeling post STEMI, but because the effect size is small, ΔECV has limited use as a clinical biomarker of remodeling. URL: https://www.clinicaltrials.gov. Unique identifier: NCT02072850.
Highlights
The natural history and pathophysiological significance of tissue remodeling in the myocardial remote zone after acute ST-elevation myocardial infarction (STEMI) is incompletely understood
The main findings are as follows: (1) remote zone Extracellular volume (ECV) 2 days post MI is associated with male sex, BMI, and a history of diabetes mellitus; (2) ΔECV is related to the extent of injury as revealed by myocardial edema; (3) ΔECV was positively associated with changes in left ventricular (LV) end-diastolic volume; (4) remote zone ECV and ΔECV were associated with NT-proBNP at baseline
In STEMI survivors, remote zone ECV is associated with sex, BMI, and a history of diabetes mellitus
Summary
The natural history and pathophysiological significance of tissue remodeling in the myocardial remote zone after acute ST-elevation myocardial infarction (STEMI) is incompletely understood. After acute ST-elevation myocardial infarction (STEMI), tissue edema and inflammatory cell recruitment occur as a response to myocyte necrosis and systemic inflammation.[1] The tissue repair response involves remodeling with collagen deposition in both the infarct and remote (noninfarcted myocardium) zones.[1,2] On the basis of recent developments with cardiac magnetic resonance (CMR) imaging, it is possible to estimate the percentage extracellular volume (ECV) in defined regions of interest.[3,4]. Our specific aims were to (1) measure ECV repeatedly in STEMI survivors in a longitudinal cohort study; (2) explore the relationships between remote zone ECV 2 days post STEMI and its absolute change at 6 months from baseline (ΔECV) with clinical characteristics of MI severity; and (3) assess whether remote zone ECV or ΔECV are associated with surrogate left ventricular (LV) outcomes during longterm follow-up.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call