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Clinical outcome of silent myocardial ischemia
1Heiden Department of Cardiology, Bikur Cholim Hospital, Jerusalem, Israel.
Insights
Silent myocardial ischemia, detected via electrocardiogram or exercise tests, indicates a higher risk of cardiac events. This risk is independent of other heart disease indicators, affecting patients with or without prior heart attacks.
Area of Science:
- Cardiology
- Clinical Medicine
- Preventive Cardiology
Background:
- Asymptomatic coronary artery disease (CAD) can manifest through abnormal resting electrocardiograms, positive exercise tests without pain, or silent ischemic episodes.
- The clinical prognosis for patients experiencing silent myocardial ischemia remains incompletely understood.
- Identifying prognostic markers for silent ischemia is crucial for patient management and risk stratification.
Purpose of the Study:
- To investigate the clinical outcome and prognostic significance of asymptomatic myocardial ischemia in patients with documented coronary artery disease.
- To determine if spontaneous ST-segment depression in asymptomatic patients provides independent prognostic information.
- To compare cardiac event rates among patients with silent, symptomatic, and mixed ischemic patterns.
Main Methods:
- The study included 356 patients with documented coronary artery disease, with 211 having a history of myocardial infarction.
- Prognostic information from spontaneous ST-segment depression was assessed.
- Independent prognostic value was evaluated against positive exercise test results, ejection fraction, and coronary artery disease extent.
Main Results:
- Asymptomatic ischemia was associated with a significantly higher coronary event rate compared to patients without ischemia.
- Spontaneous ST-segment depression provided prognostic information independent of exercise test results, ejection fraction, and coronary artery disease severity.
- Cardiac event rates were similar across silent, symptomatic, and mixed ischemia groups, irrespective of prior myocardial infarction history.
Conclusions:
- Silent myocardial ischemia is a significant predictor of adverse cardiac events.
- ST-segment depression in asymptomatic individuals carries independent prognostic value in coronary artery disease.
- Risk stratification and management strategies should consider the presence and pattern of myocardial ischemia, even in the absence of symptoms.
Abstract:
Asymptomatic coronary artery disease can be detected by an abnormal electrocardiogram at rest, by a positive exercise test result unaccompanied by pain, or by the demonstration of silent ischemic episodes during daily activities. However, the clinical outcome of patients with silent myocardial ischemia has not yet been clearly defined. In a study of 356 patients with documented coronary disease--211 of whom had previous myocardial infarction--the prognostic information of spontaneous ST-segment depression was found to be independent of that associated with a positive exercise test result, ejection fraction, and extent of arteriographically documented coronary artery disease. Patients with asymptomatic ischemia had a higher coronary event rate than those without ischemia. Cardiac event rates followed a similar pattern for patients with silent, symptomatic and mixed ischemia--whether or not there was previous myocardial infarction.