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Prognostic value of total ischemic burden in patients with stable ischemic heart disease
C Pandullo1, S Scardi, R Cesanelli
1Centro Cardiovascolare, Ospedale Maggiore, Trieste.
Insights
Transient myocardial ischemia in stable coronary artery disease patients, whether symptomatic or silent, did not impact event-free survival. The number of diseased coronary vessels predicted cardiac events, not ischemic burden.
Area of Science:
- Cardiology
- Internal Medicine
- Clinical Research
Background:
- Stable coronary artery disease patients often experience transient myocardial ischemia, with unclear prognostic significance.
- The "total ischemic burden" and its relation to cardiac events remain debated.
- Assessing silent versus symptomatic ischemia is crucial for patient outcomes.
Purpose of the Study:
- To investigate the prognostic implications of transient myocardial ischemia in stable coronary artery disease.
- To determine if the presence and type of ischemia (silent vs. symptomatic) predict cardiac events.
- To identify predictors of cardiac events in patients with coronary artery disease.
Main Methods:
- 112 patients with stable coronary artery disease and normal resting/exercise left ventricular function were studied.
- 24-hour ambulatory EKG (Holter monitoring) was performed after drug withdrawal.
- Patients were followed prospectively for cardiac events under conventional medical therapy.
Main Results:
- 82% of patients exhibited transient myocardial ischemia, with 73% of episodes being asymptomatic.
- 54% of patients with ischemia had only asymptomatic episodes; 11% had angina during ST changes.
- The number of stenotic vessels on coronary angiography predicted cardiac events (p=0.03); ischemic burden did not.
- Event-free survival was similar across silent, symptomatic, and no-ischemia groups.
Conclusions:
- The extent of transient myocardial ischemia, whether silent or symptomatic, does not appear to influence long-term cardiac event rates in stable coronary artery disease.
- The number of coronary vessels with significant stenosis is a key predictor of future cardiac events.
- Further research may clarify the role of ischemic burden in specific patient subgroups.
Abstract:
Patients with stable coronary artery disease commonly have transient myocardial ischemia with or without experiencing angina, but the prognostic implications of this "total ischemic burden" is still a matter of debate. We studied 112 consecutive patients with coronary artery disease, normal left ventricular function at rest and exercise-induced myocardial ischemia, a 24-hour ambulatory EKG was performed after drug withdrawal. The mean exercise duration was 572 +/- 192 seconds, with an ischemic threshold (ST depression = 1 mm) of 390 +/- 190 seconds). By Holter monitoring 30 patients had no ischemia and 82 (73%) had a total of 332 episodes of ST segment changes, the majority of which were asymptomatic (242/332, 73%). Among 82 patients with transient myocardial ischemia, 44 (54%) had only asymptomatic episodes. Nine patients (11%) complained of angina coincident to ST changes. Twenty-nine patients (35%) had both painful and painless ST segment alterations. All patients were prospectively followed-up while on conventional medical therapy. During a mean follow up of 25 +/- 10 months cardiac events occurred in 31 patients; there were 5 cardiac deaths, 3 non-fatal myocardial infarctions, 2 hospitalization for unstable angina and 21 revascularization procedures (PTCA or CABG). By multivariate analysis the number of stenotic vessels on coronary angiography was predictive of the events during the follow-up (p = 0.03), while other demographic, clinical, ergometric and angiographic variables were not influential. Event-free survival was similar for all subsets of transient myocardial ischemia (silent, symptomatic, or none).(ABSTRACT TRUNCATED AT 250 WORDS)