QT interval dynamics in patients with ST-elevation MI
Tomer Mann1, Amit Moses1, Anastasiea Yesaulov1
1Department of Cardiology, Tel Aviv Sourasky Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel.
Insights
Prolonged QT intervals in ST-elevation myocardial infarction (STEMI) patients are linked to higher mortality. QT dynamics and duration, particularly in women, are crucial for predicting long-term outcomes.
Area of Science:
- Cardiology
- Clinical Electrophysiology
Background:
- Prolonged QT intervals are associated with ventricular arrhythmias in ST-elevation myocardial infarction (STEMI).
- Limited understanding exists regarding QT interval dynamics, characterization, and long-term prognostic value in STEMI patients.
Purpose of the Study:
- To characterize QT interval dynamics in patients with STEMI.
- To determine the association between QT interval and mortality in STEMI patients.
Main Methods:
- Retrospective analysis of 1,054 patients hospitalized for STEMI.
- Electrocardiograms (ECGs) were analyzed for QT interval duration.
- Median follow-up of 6 years for mortality assessment.
Main Results:
- QT interval was longer in women compared to men (P=0.001).
- QT prolongation was more pronounced in females, elderly patients, and those with LAD occlusion STEMI.
- A QT cutoff of 445 ms identified a high-risk group with increased all-cause mortality.
- QT intervals measured on arrival, day 2, and before discharge correlated with long-term mortality.
Conclusions:
- QT duration is frequently prolonged in STEMI and predicts increased mortality and adverse events.
- Gender significantly influences QT interval dynamics during STEMI.
Background:
An association between excessively prolonged QT and ventricular arrhythmia in patients with ST-elevation myocardial infarction has been described; however, the QT dynamics, characterization, and long-term predictive value are not well known.
Objective:
To characterize QT interval dynamics in patients undergoing ST elevation myocardial infarction (STEMI) and determine its association with mortality.
Methods:
A retrospective analysis of 4,936 consecutive patients, hospitalized for STEMI between 01/2013-12/2021. Patients with less than three electrocardiograms (ECGs) during index hospitalization were excluded. Baseline demographics, cardiovascular history, clinical risk factors, treatment measures, laboratory results, and mortality data were retrieved from the hospital's electronic medical records.
Results:
We included 1,054 patients and 5,021 ECGs in our cohort with a median follow-up of 6 years [interquartile range (IQR) 4.3-7.4 years]. The QT was longer in women in comparison to men (428.6 ms ± 33.4 versus 419.8 ms ± 32.52, P-value = 0.001). QT prolongation was greater in females, elderly patients, and patients with STEMI caused by occlusion of the left anterior descending (LAD) coronary artery. We determined QT cutoff to be 445 ms. This value of QT divided our cohort upon arrival into a long QT group (217 patients, 26% of the cohort) and a "normal" QT group (835 patients, 74% of the cohort). The long QT group experienced an increase in combined short and long terms all-cause mortality. The QT upon arrival, on day 2 of hospitalization, and before discharge from the hospital, correlated with long-term mortality.
Conclusion:
QT duration is often prolonged during STEMI; this prolongation is associated with increased mortality and adverse events. Gender is an important mediator of QT dynamics.
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