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Risk factors and prognosis for clot formation on cardiac device leads
Ata Soleimani Rahbar1, Peyman N Azadani, Sindhura Thatipelli
1Cardiac Electrophysiology Section, Division of Cardiology, University of California, San Francisco, School of Medicine, San Francisco, California.
Insights
Cardiac device leads can form clots, particularly in patients with atrial fibrillation (AF). Anticoagulant treatment often resolves these clots without causing embolisms, improving patient outcomes.
Area of Science:
- Cardiology
- Medical Imaging
- Thrombosis
Background:
- Clot formation on cardiac device leads is not well understood.
- Cardiac device leads are essential for many patients.
- Understanding clot formation is crucial for patient safety.
Purpose of the Study:
- To determine the incidence of clot formation on cardiac device leads.
- To identify risk factors associated with clot formation.
- To describe the natural history and treatment outcomes of cardiac device lead clots.
Main Methods:
- Retrospective review of 71,888 transthoracic echocardiograms (TTE) from 2005-2011.
- Identification of patients with device leads and adhered clot, excluding endocarditis.
- Selection of age-matched controls without clot for comparison.
Main Results:
- 1.4% of patients with cardiac devices showed clot on leads (15/1086).
- Atrial fibrillation (AF) was a significant risk factor for clot formation (OR 8x univariate, still significant multivariate).
- Anticoagulant therapy led to clot resolution or shrinkage in 8/9 patients, with no embolic events.
Conclusions:
- Patients with AF have a higher risk of clot formation on cardiac device leads.
- Intensified anticoagulant or antiplatelet therapy is effective in resolving device lead clots.
- Prompt treatment of cardiac device lead clots can prevent embolic complications.
Background:
Clot formation on cardiac device leads is poorly understood. We sought to determine how often clot is seen on device leads by transthoracic echo (TTE), identify risk factors, and to describe the natural history of this phenomenon.
Methods:
We reviewed 71,888 echocardiographic studies performed at the University of California, San Francisco from 2005 to 2011. We searched for cases where clot was found adhered to a device lead with no diagnosis of endocarditis. For every case, three age-matched controls with a device but no clot were selected from the echo database.
Results:
We found 15 cases with clot adhered to a device lead among 1,086 patients with devices who had TTE (1.4%). In univariate analysis, females had more than four times greater odds of having a clot on their device lead and patients with a history of atrial fibrillation (AF) had an eight times greater odds. Percentage mode switch was also associated with clot formation. Only AF was still associated with clot formation after multivariate analysis. Follow-up data were available for nine of 15 patients. All nine patients had intensification of their anticoagulant/antiplatelet regimen following clot discovery. Complete resolution or shrinkage of clot was observed in eight of nine patients. The one case with no change was a patient who continued taking only aspirin (higher dose) after clot discovery. None of the nine patients had embolic phenomenon.
Conclusion:
Patients with AF are at higher risk for clot formation on device leads. After clot detection, treatment with anticoagulants usually results in resolution of the clot without embolic phenomenon.
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