From the Guidelines
Post-myocardial infarction (MI) rupture is most likely to occur in patients with first MI, anterior infarction, the elderly, and women.
Risk Factors
- Hypertension during the acute phase of STEMI
- Lack of antecedent angina or prior MI
- Absence of collateral blood flow
- Q waves on ECG
- Use of corticosteroids or nonsteroidal anti-inflammatory drugs (NSAIDs), as they may increase the risk of major adverse events, including impaired infarct healing and possibly increased risk of rupture following transmural infarction 1
- Administration of fibrinolytic therapy >14 hours after symptom onset 1
Diagnosis and Management
Diagnosis of post-MI rupture can be made using transthoracic echocardiography, which can recognize pseudoaneurysm formation with contained rupture and tamponade 1. Emergency surgery should be considered in these cases, although mortality rates are high, approaching 60% 1.
From the Research
Risk Factors for Post-Myocardial Infarction Rupture
The risk factors for post-myocardial infarction (MI) rupture can be identified from various studies, including:
- Female gender 2, 3, 4, 5
- Older age 2, 3, 5
- Infarction at left anterior descending coronary artery (LAD) 2
- Anterior wall infarction 2, 4
- New-onset MI 2
- Non-smoking status 2
- Single-vessel disease 2
- Acute hyperglycemia 4
- Thrombocytopenia (platelets <15 × 10^4/µL) 4
- Incomplete revascularization [post-PCI thrombolysis in myocardial infarction (TIMI) <3] 4
- Hypertension 3, 5
- Increased Killip class 5
- Lower estimated glomerular filtration rate 5
- Q wave MI 5
Clinical Characteristics and Time of Occurrence
Clinical characteristics and time of occurrence of cardiac rupture may differ in the PCI era, with:
- Early cardiac rupture (≤72 h) associated with low systolic blood pressure, anterior infarction, acute hyperglycemia, Killip class >1, and post-PCI TIMI <3 4
- Late cardiac rupture (>72 h) associated with Killip class >1 and thrombocytopenia 4
- Peak incidence of early cardiac rupture between 12:00 and 21:00 h, and late cardiac rupture between 6:00-12:00 and 21:00-24:00 h 4
Pathogenesis and Therapeutic Interventions
Research using mouse models suggests that acute ventricular remodeling is the fundamental change leading to rupture, and has defined several key factors that determine the risk of rupture, including: