Is silent ischemia on the routine admission ECG an important finding?
S L Bridges1, J S Hollowell, S W Stagg
1Department of Internal Medicine, University of Texas Medical Branch, Galveston.
Insights
Electrocardiogram (ECG) changes indicating silent ischemia in patients without coronary artery disease predict a higher risk of cardiac events or death. This finding highlights the importance of ECG screening for early risk identification.
Area of Science:
- Cardiology
- Diagnostic Medicine
- Preventive Cardiology
Background:
- Coronary artery disease (CAD) risk factors are prevalent in the general population.
- Silent ischemia, detected via electrocardiogram (ECG) changes, may indicate underlying cardiac issues.
- Early identification of high-risk patients is crucial for timely intervention.
Purpose of the Study:
- To investigate if ST-T changes suggestive of silent ischemia on admission ECGs identify high-risk patients.
- To assess the association between silent ischemia on ECG and cardiac events or death in patients without known CAD.
Main Methods:
- Prospective cohort study at a tertiary care university hospital.
- Screening of all admitted patients over a 5-month period.
- Comparison of outcomes between patients with (ischemia group) and without (control group) silent ischemia on admission ECGs, matched for CAD risk factors.
Main Results:
- The silent ischemia group (n=54) showed a significantly higher incidence of cardiac events or death within 3 weeks (13%) compared to the control group (1%) (p < 0.02).
- At 6 months, 15% of the silent ischemia group experienced cardiac events versus 3% in the control group (p = 0.02).
Conclusions:
- Silent ischemia on admission ECG is a significant predictor of adverse cardiac events and death in patients with CAD risk factors but no known CAD.
- Admission ECG findings of silent ischemia can aid in stratifying risk and guiding management in asymptomatic individuals.
Abstract:
The authors' objective was to determine if, in the absence of known coronary artery disease, ST-T changes suggestive of silent ischemia on the admission electrocardiogram (ECG) identify a group of patients at high risk for cardiac event or death. A prospective cohort study was undertaken at the university hospital of a tertiary care center. All patients admitted to the hospital during the 5-month study period were screened. The authors found 54 patients with risk factors but no symptoms of coronary artery disease whose admission ECGs showed silent ischemia (ischemia group), and 71 patients with similar risk of coronary artery disease but without admission ECGs showing silent ischemia (control group). Three-week and 6-month incidences of angina, myocardial infarction, and death among patients in the silent ischemia and control groups were compared. Seven (13%) patients in the silent ischemia group had cardiac events or noncardiac death in the subsequent 3 weeks versus one (1%) noncardiac death in the control group (p < 0.02). At 6 months, eight (15%) patients in the silent ischemia group versus two (3%) in the control group had cardiac events (p = 0.02). It is concluded that among patients with risk factors but no symptoms of coronary artery disease, silent ischemia on the admission ECG is associated with an increased likelihood of short-term death or cardiac event.
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