Temporal Evolution of Myocardial Hemorrhage and Edema in Patients After Acute ST-Segment Elevation Myocardial Infarction: Pathophysiological Insights and Clinical Implications

J Am Heart Assoc. 2016 Feb 23;5(2):e002834. doi: 10.1161/JAHA.115.002834.

Abstract

Background: The time course and relationships of myocardial hemorrhage and edema in patients after acute ST-segment elevation myocardial infarction (STEMI) are uncertain.

Methods and results: Patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention underwent cardiac magnetic resonance imaging on 4 occasions: at 4 to 12 hours, 3 days, 10 days, and 7 months after reperfusion. Myocardial edema (native T2) and hemorrhage (T2*) were measured in regions of interest in remote and injured myocardium. Myocardial hemorrhage was taken to represent a hypointense infarct core with a T2* value <20 ms. Thirty patients with ST-segment elevation myocardial infarction (mean age 54 years; 25 [83%] male) gave informed consent. Myocardial hemorrhage occurred in 7 (23%), 13 (43%), 11 (33%), and 4 (13%) patients at 4 to 12 hours, 3 days, 10 days, and 7 months, respectively, consistent with a unimodal pattern. The corresponding median amounts of myocardial hemorrhage (percentage of left ventricular mass) during the first 10 days after myocardial infarction were 2.7% (interquartile range [IQR] 0.0-5.6%), 7.0% (IQR 4.9-7.5%), and 4.1% (IQR 2.6-5.5%; P<0.001). Similar unimodal temporal patterns were observed for myocardial edema (percentage of left ventricular mass) in all patients (P=0.001) and for infarct zone edema (T2, in ms: 62.1 [SD 2.9], 64.4 [SD 4.9], 65.9 [SD 5.3]; P<0.001) in patients without myocardial hemorrhage. Alternatively, in patients with myocardial hemorrhage, infarct zone edema was reduced at day 3 (T2, in ms: 51.8 [SD 4.6]; P<0.001), depicting a bimodal pattern. Left ventricular end-diastolic volume increased from baseline to 7 months in patients with myocardial hemorrhage (P=0.001) but not in patients without hemorrhage (P=0.377).

Conclusions: The temporal evolutions of myocardial hemorrhage and edema are unimodal, whereas infarct zone edema (T2 value) has a bimodal pattern. Myocardial hemorrhage is prognostically important and represents a target for therapeutic interventions that are designed to preserve vascular integrity following coronary reperfusion.

Clinical trial registration: URL: https://clinicaltrials.gov/. Unique identifier: NCT02072850.

Keywords: magnetic resonance imaging; myocardial edema; myocardial hemorrhage; myocardial infarction; pathophysiology; reperfusion injury.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Edema, Cardiac / diagnosis
  • Edema, Cardiac / etiology*
  • Edema, Cardiac / physiopathology
  • Female
  • Hemorrhage / diagnosis
  • Hemorrhage / etiology*
  • Hemorrhage / physiopathology
  • Humans
  • Longitudinal Studies
  • Magnetic Resonance Imaging, Cine
  • Male
  • Middle Aged
  • Myocardial Infarction / complications*
  • Myocardial Infarction / diagnosis
  • Myocardial Infarction / physiopathology
  • Myocardial Infarction / therapy*
  • Myocardial Reperfusion Injury / diagnosis
  • Myocardial Reperfusion Injury / etiology*
  • Myocardial Reperfusion Injury / physiopathology
  • Myocardium / pathology*
  • Observer Variation
  • Percutaneous Coronary Intervention / adverse effects*
  • Predictive Value of Tests
  • Reproducibility of Results
  • Time Factors
  • Treatment Outcome

Associated data

  • ClinicalTrials.gov/NCT02072850