Related Experiment Video
Updated: Apr 29, 2026

Coronary Artery Ligation and Intramyocardial Injection in a Murine Model of Infarction
Published on: June 7, 2011
Coronary Culprit Lesion Location and Intramyocardial Hemorrhage in STEMI
Fritz Oberhollenzer1, Ivan Lechner1, Christina Tiller1
1University Clinic of Internal Medicine III, Cardiology and Angiology (F.O., I.L., C.T., M.H., A.K., P.F., A.B., B.M., S.J.R., M.R.), Medical University of Innsbruck, Anichstrasse 35, Austria.
Insights
Intramyocardial hemorrhage (IMH) is more common in patients with circumflex artery (CX) infarctions. This finding suggests CX infarctions are a high-risk phenotype requiring targeted cardioprotective strategies.
Area of Science:
- Cardiology
- Medical Imaging
- Pathophysiology
Background:
- Intramyocardial hemorrhage (IMH) is a significant predictor of poor outcomes in ST-segment-elevation myocardial infarction (STEMI).
- Identifying factors associated with IMH is crucial for developing targeted therapies.
Purpose of the Study:
- To investigate the relationship between the location of the coronary culprit lesion and the presence of IMH in patients with acute STEMI.
- To identify specific coronary artery territories associated with a higher risk of IMH.
Main Methods:
- Cardiac magnetic resonance imaging (CMR) with T2* mapping was performed on 767 STEMI patients.
- Coronary culprit vessel and lesion characteristics, Thrombolysis in Myocardial Infarction (TIMI) flow, and collateral circulation were assessed.
- IMH presence was the primary endpoint; major adverse cardiac events (MACE) were assessed at 12 months.
Main Results:
- IMH was detected in 35% of patients.
- The prevalence of IMH was significantly higher in patients with circumflex artery (CX) (44%) compared to left anterior descending (39%) and right coronary artery (27%) culprit lesions (P<0.001).
- CX infarction remained independently associated with IMH (OR, 1.27; P=0.005) and showed the highest rate of MACE (7%).
Conclusions:
- Circumflex artery (CX) infarctions are independently associated with the highest risk of IMH.
- Limited collateral circulation in CX infarctions may contribute to this increased susceptibility.
- CX infarctions represent a high-risk phenotype warranting focused cardioprotective interventions.
Background:
Intramyocardial hemorrhage (IMH) is a major determinant of adverse outcome in patients with ST-segment-elevation myocardial infarction, therefore making it a promising therapeutic target. This study aimed to investigate the association between coronary culprit lesion location and IMH in acute ST-segment-elevation myocardial infarction.
Methods:
We analyzed 767 patients with ST-segment-elevation myocardial infarction undergoing cardiac magnetic resonance imaging, including T2* mapping at 4 (interquartile range, 3-5) days after infarction. Coronary culprit vessel and lesion, Thrombolysis in Myocardial Infarction flow, and collateral circulation were assessed. The primary end point was the presence of IMH on cardiac magnetic resonance. An exploratory clinical end point at 12 months was defined as major adverse cardiac events, which comprised all-cause mortality, reinfarction, and new congestive heart failure.
Results:
Median age was 59 (interquartile range, 53-67) years, and 19% (n=144) were female. IMH was detected in 265 (35%) patients. IMH was present in 27% (n=76/286) of patients with right coronary artery, in 39% (n=136/351) with left anterior descending artery, and 44% (n=48/109) with circumflex artery (CX) as the culprit lesion (P<0.001). Segment 11 (CX proximal) showed the highest (n=23/41, 56%), segment 1 (right coronary artery proximal) the lowest risk for IMH (n=22/85, 26%). CX infarction remained independently associated with IMH (odds ratio, 1.27 [95% CI, 1.07-1.50]; P=0.005) after adjustment for angiographic and clinical IMH determinants, including Thrombolysis in Myocardial Infarction flow, ischemic time, and troponin T concentration. Collateral flow was least frequent in CX infarctions (n=15/109, 14%) compared with right coronary artery (n=117/286, 41%) and left anterior descending infarctions (n=101/351, 29%; P<0.001). Patients with CX infarction showed the highest rate of major adverse cardiac events (7%) compared with left anterior descending (6%) and right coronary artery (2%) infarctions (P=0.039).
Conclusions:
CX infarctions were independently associated with the highest risk of IMH. The low prevalence of collateral circulation may contribute to this susceptibility. These findings define CX infarctions as a high-risk phenotype that may benefit from targeted cardioprotective strategies.
Related Concept Videos
Acute Coronary Syndrome I: Introduction
Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations
Acute Coronary Syndrome III: Diagnostic Studies
Coronary Artery Disease II: Pathophysiology
Myocarditis I: Introduction
Myocarditis II: Clinical Features and Diagnostic Tests

