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Microembolic load in asymptomatic patients with cardiac aneurysm, severe ventricular dysfunction, and atrial
D G Nabavi1, S Arato, D W Droste
1Department of Neurology, Westfälische Wilhelms-Universität, Münster, Germany. Nabavi@uni-muenster.de
Insights
Cerebral microemboli (ME) are present in asymptomatic patients with left ventricular aneurysm, dysfunction, or atrial fibrillation. Ineffective anticoagulation and increased platelet aggregation significantly contribute to ME generation.
Area of Science:
- Neurology
- Cardiology
- Hemorheology
Background:
- Transcranial Doppler sonography detects cerebral microemboli (ME) from cardiac or carotid sources.
- Limited studies investigate ME in specific cardiac subgroups and hemorheological links.
- This study focuses on patients with left ventricular aneurysm (LVA), left ventricular dysfunction (LVD), and chronic atrial fibrillation (AF).
Purpose of the Study:
- To assess microembolic activity in neurologically asymptomatic patients with LVA, LVD, or AF.
- To investigate the relationship between microembolization and hemorheological parameters in these patient groups.
Main Methods:
- 142 patients with LVA (n=52), LVD (n=43), or AF (n=47) were enrolled.
- Exclusion of other embolic disorders.
- 30-minute unilateral middle cerebral artery monitoring for ME, followed by blood analysis for coagulation, plasma viscosity, and platelet reactivity.
Main Results:
- Overall ME prevalence was 31%, with LVA patients showing slightly higher rates (37%).
- Trends towards higher ME prevalence were observed with remote embolic events, ineffective anticoagulation, increased platelet aggregation, or increased plasma viscosity.
- A significant association between ineffective anticoagulation and increased platelet aggregation with higher ME rates was found via logistic regression.
Conclusions:
- Asymptomatic patients with LVA, LVD, and AF exhibit low ongoing microembolic activity.
- An activated coagulation system and increased platelet aggregation are key contributors to microemboli generation in these patients.
Abstract:
Transcranial Doppler sonography has become a widely used method for detecting cerebral circulating microemboli (ME) arising from the carotid arteries or the heart. Yet, studies on subgroups of patients with distinct cardiac sources of embolism are still limited. The same holds true for investigation on the relationship between microembolization and hemorheological parameters. A total of 142 patients suffering from left ventricular aneurysm (LVA, n = 52), severe left ventricular dysfunction (LVD, n = 43), or chronic atrial fibrillation (AF, n = 47) were enrolled in this study. All patients had been neurologically asymptomatic for at least 1 month. Further relevant embolic disorders of the carotid arteries and the heart had been excluded. Unilateral monitoring for ME over the middle cerebral artery was performed for 30 min. Blood was drawn after each monitoring for determination of plasmatic coagulation parameters, as well as plasma viscosity, and platelet reactivity. The overall prevalence of ME was 31%, with a slightly higher prevalence in patients with LVA (37%) compared to patients suffering from AF (30%) or LVD (26%). With single-factor analysis, a trend towards higher ME prevalences was found with (a) a history of remote embolic events, (b) ineffective anticoagulation, (c) increased platelet aggregation, or (d) increased plasma viscosity (all p > 0.1). The combination of ineffective anticoagulation in conjunction with increased platelet aggregation, however, was significantly associated with higher ME rates even after adjustment for other factors by logistic regression analysis. Our results demonstrate a low ongoing microembolic activity in asymptomatic patients suffering from LVA, LVD and AF. An activated plasmatic coagulation system together with increased platelet aggregation contributes to ME generation.