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Ultrastructural studies of unstable angina in living man
A I Gotlieb1, M R Freeman, T A Salerno
1Department of Pathology, St. Michael's Hospital, University of Toronto, Canada.
Insights
This study investigated platelet aggregation in unstable angina patients undergoing bypass surgery. Platelet aggregates were found in some biopsies, confirming their presence in this condition.
Area of Science:
- Cardiovascular Medicine
- Hematology
- Pathology
Background:
- Unstable angina is a critical condition often linked to microvascular dysfunction.
- The role of platelet aggregation in the microvasculature of unstable angina patients requires further elucidation.
Purpose of the Study:
- To assess the extent and presence of platelet aggregation within the cardiac microvasculature of patients with refractory unstable angina.
- To correlate microvascular findings with coronary angiograms and thallium scans.
Main Methods:
- Nineteen patients with refractory unstable angina undergoing aortocoronary bypass were studied.
- Cardiac muscle and microvasculature biopsies were analyzed using ultrastructural examination.
- Findings were correlated with coronary angiography and thallium scan results.
Main Results:
- Platelet aggregates were identified in four (21%) of the patient biopsies.
- Two biopsies with platelet aggregates also showed thrombus by angiographic criteria.
- Biopsies from areas with thallium defects showed increased white blood cells but no acute myocardial infarction.
Conclusions:
- This study confirms the presence of platelet aggregates in the microvasculature of patients with unstable angina.
- The frequency of observed platelet aggregates was lower than reported in previous autopsy studies.
- No significant correlations were found between ultrastructural microvascular findings and coronary angiograms or thallium scans.
Abstract:
Nineteen patients with refractory unstable angina who were undergoing aortocoronary bypass were studied to assess the extent of platelet aggregation present in the microvasculature. Ultrastructural findings on the morphology of cardiac muscle and microvasculature were correlated with the findings on coronary angiograms and thallium scans. There were no significant correlations. The presence of platelet aggregates was identified in four biopsies, two of which had thrombus by angiographic criteria. Biopsy in areas with thallium defects revealed an increased prevalence of white blood cells without acute myocardial infarction. This study confirms the presence of platelet aggregates in patients with unstable angina, albeit at a reduced frequency when compared with autopsy studies.