Early risk stratification for arrhythmic death in patients with ST-elevation myocardial infarction
Majid Haghjoo1, Reza Kiani, Amir Farjam Fazelifar
1Department of Pacemaker and Electrophysiology, Rajaie Cardiovascular Medical and Research Center, School of Medicine, Iran University of Medical Sciences, Tehran, Iran. majid.haghjoo@gmail.com
Insights
Sudden cardiac death risk in ST-elevation myocardial infarction (MI) patients can be predicted. Ejection fraction (EF) below 40%, abnormal heart rate variability (HRV), and signal-averaged electrocardiography (SAECG) are key indicators.
Area of Science:
- Cardiology
- Clinical Medicine
- Medical Diagnostics
Background:
- Sudden cardiac death (SCD) is a major cause of mortality in ST-elevation myocardial infarction (MI) patients.
- Cost-effective risk stratification is crucial for post-MI patients before considering expensive interventions like implantable cardioverter-defibrillators.
Purpose of the Study:
- To identify reliable predictors of sudden cardiac death in patients following ST-elevation myocardial infarction.
- To evaluate the efficacy of ejection fraction, heart rate variability, and signal-averaged electrocardiography in risk stratification.
Main Methods:
- One hundred thirty-seven ST-elevation MI patients underwent echocardiography, Holter monitoring, and signal-averaged electrocardiography (SAECG).
- Patients were followed for 12±3 months to assess outcomes, including sudden cardiac death.
Main Results:
- A significant association was found between ejection fraction (EF) less than 40% and arrhythmic events (P<0.001).
- EF<40% demonstrated 100% sensitivity and 76.95% positive predictive value for SCD.
- Abnormal heart rate variability (HRV) and SAECG also significantly predicted sudden death (P=0.02 and P=0.003, respectively).
Conclusions:
- Ejection fraction less than 40% is the strongest predictor of sudden cardiac death in post-MI patients.
- Abnormal HRV and SAECG are valuable supplementary predictors for enhanced risk stratification.
Background:
Sudden cardiac death is a leading cause of death in patients with ST-elevation myocardial infarction (MI). According to high cost of modern therapeutic modalities it is of paramount importance to define protocols for risk stratification of post-MI patients before considering expensive devices such as implantable cardioverter-defibrillator.
Methods:
One hundred and thirty seven patients with acute ST-elevation MI were selected and underwent echocardiographic study, holter monitoring and signal-averaged electrocardiography (SAECG). Then, the patients were followed for 12 +/-3 months.
Results:
During follow-up, 13 deaths (9.5%) occurred; nine cases happened as sudden cardiac death (6.6%). The effect of ejection fraction (EF) less than 40% on occurrence of arrhythmic events was significant (P<0.001). Sensitivity and positive predictive value of EF<40% was 100% and 76.95% respectively. Although with lesser sensitivity and predictive power than EF<40%, abnormal heart rate variability (HRV) and SAECG had also significant effects on occurrence of sudden death (P=0.02 and P=0.003 respectively). Nonsustained ventricular tachycardia was not significantly related to risk of sudden death in this study (P=0.20).
Conclusion:
This study indicated that EF less than 40% is the most powerful predictor of sudden cardiac death in post MI patients. Abnormal HRV and SAECG are also important predictors and can be added to EF for better risk stratification.
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