My patient with a thrombosed hemodialysis access is found to have an asymptomatic segmental pulmonary embolism following a vascular access declotting procedure. Does he need systemic anticoagulation?

There is no firm evidence either for or against the use of systemic anticoagulants (ACs) in patients with asymptomatic pulmonary embolism (PE) following hemodialysis vascular access declotting (HVAD).  

However, despite the common occurrence of asymptomatic PE following HVAD procedures (~40%), symptomatic PE—at times fatal—has also been reported in these patients1,2.

In the absence of hard data and any contraindications, anticoagulation can be justified in our patient for the following reasons:

  • Asymptomatic segmental PE is commonly treated as symptomatic PE irrespective of setting2,3
  • Hemodialysis patients are often considered hypercoagulable due to a variety of factors eg, platelet activation due to extracorporeal circulation, anti-cardiolipin antibody, lupus anticoagulant, decreased protein C or S activity, and/or reduced anti-thrombin III activity4-7
  • Overall, chronic dialysis patients have higher incidence of PE compared to the general population8
  • There is no evidence that asymptomatic PE following HVAD has a more benign course compared to that in other settings
  • Untreated PE may be associated with repeated latent thrombosis or progression of thrombosis in the pulmonary artery5

 

References

  1. Calderon K, Jhaveri KD, Mossey R. Pulmonary embolism following thrombolysis of dialysis access: Is anticoagulation really necessary? Semin Dial 2010:23:522-25. https://www.ncbi.nlm.nih.gov/pubmed/21039878
  2. Sadjadi SA, Sharif-Hassanabadi M. Fatal pulmonary embolism after hemodialysis vascular access declotting. Am J Case Rep 2014;15:172-75. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4004792/pdf/amjcaserep-15-172.pdf
  3. Chiu V, O’Connell C. Management of the incidental pulmonary embolism. AJR 2017;208:485-88. http://www.ajronline.org/doi/pdf/10.2214/AJR.16.17201
  4. Kearon C, Akl EA, Ornelas J, et al. Antithrombotic therapy for VTE disease: Chest guideline and expert panel report. CHEST 2016;149:315-52. http://journal.chestnet.org/article/S0012-3692(15)00335-9/fulltext
  5. Yamasaki K, Haruyama N, Taniguchi M, et al. Subacute pulmonary embolism in a hemodialysis patient, successfully treated with surgical thrombectomy. CEN Case Rep 2016;5:74-77 https://link.springer.com/article/10.1007/s13730-015-0195-9
  6. Nampoory MR, Das KC, Johny KV, et al. Hypercoagulability, a serious problem in patients with ESRD on maintenance hemodialysis, and its correction after kidney transplantation. Am J Kidney Dis 2003;42:797-805. https://www.ncbi.nlm.nih.gov/pubmed/14520631
  7. O’Shea SI, Lawson JH, Reddan D, et al. Hypercoagulable states and antithrombotic strategies in recurrent vascular access site thrombosis. J Vasc Surg 2003;38: 541-48. http://www.jvascsurg.org/article/S0741-5214(03)00321-5/pdf
  8. Tveit DP, Hypolite IO, Hshieh P, et al. Chronic dialysis patients have high risk for pulmonary embolism. Am J Kidney Dis 2002;39:1011-17. https://www.ncbi.nlm.nih.gov/pubmed/11979344
My patient with a thrombosed hemodialysis access is found to have an asymptomatic segmental pulmonary embolism following a vascular access declotting procedure. Does he need systemic anticoagulation?

Why is there a predilection for the tricuspid valve (TV) infection among injection drug users (IDUs) with infective endocarditis (IE)?

Although right-sided IE accounts for only 9% of IE cases among non IDUs, in IDUs it accounts for over three-quarters of IE cases1.  

Several potential mechanisms have been posited to explain susceptibility of TV to infection in IDUs, including endothelial damage due to repeated inoculation of small bacterial loads, specific substances (eg talc) injected with drugs,  cocaine-induced vasospasm and thrombus formation, and drug-induced pulmonary hypertension associated with increased pressure gradients and turbulence.  In addition, facilitation of bacterial adhesion due to the deposition of immune complexes (eg antibody vs antigens in injected drugs) on the TV and coating of the injected particulate matter with bacterial adherence matrix molecules on valve surfaces may also play an important role1,2.

Add to these potential factors a higher risk nasal and cutaneous colonization with Staphylococcus aureus (a common cause of IE) among IDUs, and we have a perfect storm!

References

  1. Frontera JA, Gradon JD. Right-sided endocarditis in injection drug users: review of proposed mechanisms of pathogenesis. Clin Infect Dis 2000;30:374-9.
  2. Chahood J, Yakan AS, Saad H, et al. Right-sided infective endocarditis and pulmonary infiltrates: An update. Cardiol Rev 2016;24:230-37.
Why is there a predilection for the tricuspid valve (TV) infection among injection drug users (IDUs) with infective endocarditis (IE)?