Venous Thromboembolism

by Christopher Sirridge, MD

Hypercoagulability – a clot in the wrong place at the wrong time – is the No. 1 pathophysiological cause of death worldwide. The reason is that the vast majority of myocardial infarctions (MI), cerebrovascular accidents (CVA), pulmonary embolisms and vascular occlusions of other vital organs are almost always because of an acute clot. Therefore, the management of patients so that they do not clot in the wrong place at the wrong time is not only beneficial but the “Holy Grail” of survival.

Individualized Plans

The biggest therapeutic dilemma in treating clots is the balance between preventing clotting vs. the No. 1 significant side effect – abnormal bleeding.

As of January 1, there are significant guidelines about how and when to anticoagulate patients and what agents one would consider as the best choice for each individual patient. Herein lies the key to all anticoagulation; when applying significant, time-honored guidelines for anticoagulation, one always has to individualize the plan for each unique and individual patient. Patients come in different ages and sizes; with different diseases, hepatic and renal functions, expectations and comorbidities. With that in mind, it’s good to have as many medication options available as possible, so you can fit the vast number of unique patients.

Key Questions

There are several key questions that are easy but need to be asked early to help doctors start to individualize their patients:

1) Were you born with clotting issues or were they acquired? If the patient was born with the problem, is there a history that supports a family disease?

2) Was the coagulant event (clot) provoked?

3) Where was the clot (or how many places were there clots), and how much damage was done by the clot?

Once a physician has this information, the data will help decide:

1) Will the patient be on some form of anticoagulation for the short term, an extended period or indefinitely?

2) Which type of anticoagulant is best for that patient in the short term, midrange and long run?

There are national guidelines  for how long one should anticoagulate patients for the type of clot they experienced.


Is the patient a candidate for any of the new anticoagulants (Novel Oral Anticoagulants or NOACs) that have come onto the market since October 2010? (Note that October 2010 was the date of the first NOACs in 56 years.) We now have 3 new anticoagulants:

1. Dabigatran (brand name Pradaxa®): a direct thrombin inhibitor 2. Rivaroxaban (brand name Xarelto®): a direct factor Xa inhibitor 3. Apixaban (brand name Eliquis®): a direct factor Xa inhibitor

A thorough understanding of each anticoagulant’s benefits and side effects helps clinicians make the best decision for the individual patient.

Benefits of NOACs:

  • Work immediately 
  • No constant monitoring needed 
  • Vitamin K deficient diet is not required 
  • Low molecular-weight heparin is not required for coverage of elective procedures

Detractors of NOACs:

  •  Less clinical experience 
  • Not all are FDA approved for all indications 
  • No standard lab test for clinical monitoring
  • No standard antidote for bleeding in presence of these drugs 
  • Expense

The ideal patient for NOACs is: 

  • Physically active 
  • Has good kidney and liver function 
  • Not at risk for abnormal bleeding

The ideal Coumadin patient has: 

  • Altered kidney and liver function
  • Requires close monitoring for therapeutic efficacy 
  • Reduced expense is vital

Additional items to consider in choosing Coumadin vs. NOACs: 

  • Failure of previous agents 
  • Patient compliance 
  • Economics
  • Standard of care within the patient’s community

In the future, it is likely that there will be laboratory monitoring of the NOACs and possibly development of direct antidotes for bleeding problems.  

Primary Question

The primary question that I am asked is, “Regardless of the situation that the doctor and patient find themselves in, are the newer NOACs better drugs – more effective anticoagulants – regardless of the side effect profile or expense?”

My answer is that with nonvalvular Afib, the use of NOACs has been found to be superior to Coumadin in the prevention of embolic strokes and in the reduction of CNS bleeds. They have, however, been associated with higher rates of GI bleeding, and in a few studies, higher rates of MI upon rapid discontinuation of the medications.

The key wisdom for clinicians in the choice of the right anticoagulant for the right patient requires:

  • Getting an excellent history and physical 
  • Thorough knowledge of the patient’s clot disease 
  • Knowing a patient’s: 
    • Liver/kidney function 
    • Propensity of bleed
    • Compliance propensity 
    • Budget

View the complete PowerPoint presentation.

Christopher Sirridge, MD

Christopher SirridgeDr. Sirridge earned his medical degree from the University of Missouri-Kansas City. He completed a residency at Cleveland Clinic Foundation and fellowship at Mayo School of Medicine-Rochester. He is board certified in internal medicine, hematology and medical oncology. He has a special focus on coagulation disorders, geriatric hematology, lymphoproliferative disorders, combined variable immunodeficiency, and bariatric surgery induced hematologic disorders.

To learn more, call 816-746-4570.