The Curbsiders Internal Medicine Podcast

Episode #499: Inpatient DOAC Dilemmas with Dr. Jori May

Date: September 22, 2025
Guest: Dr. Jori May, Assistant Professor of Medicine, Hematology/Oncology, UAB
Hosts: Dr. Moni Amin & Dr. Meredith Trubitt

Episode Overview

This episode tackles the complex topic of Direct Oral Anticoagulant (DOAC) management for hospitalized patients, focusing on “DOAC dilemmas” like assessing treatment failure, agent selection, considerations for special populations (renal dysfunction, obesity, anatomical issues), and navigating real-world clinical uncertainty. Guest hematologist Dr. Jori May brings practical clinical pearls for the hospitalist audience, discussing how to critically evaluate patients with VTE or other indications on DOACs, and how to troubleshoot when things aren’t going as planned.

Key Discussion Points & Clinical Pearls

1. Defining Anticoagulation (DOAC) Failure

• True DOAC failure is rare. Must have definitive evidence of a new thrombus despite adequate anticoagulation.
• Important to confirm:
  • Drug adherence/fill history (check pharmacy records).
  • Proper dosing for the right indication (e.g., VTE vs. atrial fibrillation).
  • Correct administration (apixaban BID; rivaroxaban with food).
• Also check for secondary risk factors: malignancy, anatomical stasis, or hypercoagulable conditions.

“Anticoagulation failure is definitive evidence of a new thrombus despite adequate anticoagulation, and there’s a lot of caveats… ultimately the most important part is how we approach these cases.”
— Dr. Jori May [11:05]

2. Assessing Adequacy of Anticoagulation

• Pharmacy fill history is often more reliable than patient self-reports.
• Ensure correct DOAC is chosen for the indication.
• Pay attention to missed doses: One missed dose rarely matters. Extended gaps (1-2 days) are more worrisome.
• Anti-Xa levels: Only helpful if the assay is calibrated for oral Xa inhibitors; otherwise, at best a “yes/no” for recent drug ingestion ([20:29]).

3. Imaging and Defining New vs. Chronic Clot

• Compare to old imaging when possible; if not available, directly consult radiology for clues to chronicity.
• Imaging findings (e.g., vein dilation/contraction, clot characteristics) can give context.
• D-dimer: May help distinguish new versus old clot, but is only a “piece of the puzzle” and most useful several months out from the index clot, not during the acute/recovery phase ([41:55], [42:15]).

“Pick up the phone and call your radiologist... They can sometimes glean more from the images than what the report says.”
— Dr. Jori May [33:37]

4. Hypercoagulable & Anatomical Considerations

• Always look for active cancer, pro-thrombotic drugs, or anatomical flow disruption (e.g., May-Thurner, thoracic outlet, post-thrombotic syndrome).
• Recognize when recurrent clotting may reflect anatomy or underlying disease rather than anticoagulant “failure.”

5. Special Populations: Dosing and Choice

• Obesity: DOACs generally OK even for BMI up to 40–50 (“really extreme” BMI > 55–60 is data-free and caution is advised; consider warfarin for initial intensive therapy).
• Renal Failure (including Dialysis): Apixaban preferred due to less reliance on renal clearance, but consider dose reduction for secondary prevention or high bleeding risk ([25:56], [28:44]).
  • Warfarin is not a perfect choice in ESRD either.
• Altered anatomy/surgery: Site of absorption matters (colonic for apixaban; consider alternative if colonic resection).

“For BMI... we do feel comfortable with DOACs in the obese up to a point. For extremes, I still have a little bit of hesitation.”
— Dr. Jori May [25:56]

6. When Symptoms Worsen During DOAC: What Next?

• Don’t reflexively switch agents; assess for true failure.
• Consider temporarily switching to parenteral therapy (enoxaparin) if symptoms worsen during first three months, rather than moving rapidly to warfarin ([44:44]).
• Heparin drips have variable kinetics and are not “more powerful.”

7. DOAC Agent Switching & When to Choose Warfarin

• Real world: No strong data to prefer switching from one oral Xa inhibitor to another.
• Only swap if patient preference—e.g., once versus twice daily dosing.
• Warfarin: Still used for mechanical valves, true triple-positive antiphospholipid syndrome, pregnancy/breastfeeding, severe nonadherence situations—but daily DOACs (e.g. rivaroxaban) often superior for patients with adherence challenges ([53:17], [54:08]).
• Dabigatran is rarely used, except sometimes in young menstruating patients with bleeding on other anticoagulants ([51:56]).

“If I have a patient, I have any concern that they’re not gonna be able to stick with warfarin requirements… a once-a-day DOAC is better.”
— Dr. Jori May [54:08]

8. When to Consider Additional Hypercoagulability Work-up

• If truly recurrent clot, screen for antiphospholipid syndrome (use up-to-date [ACR/EULAR 2023] criteria).

9. Expanded Indications for DOACs

• LV thrombus: DOACs now supported by latest science as acceptable alternative to warfarin.
• Other “abnormal” sites (CVST, splanchnic): DOACs likely safe and effective, though evidence is observational ([56:53], [58:32]).

“At this point, I feel comfortable, based on observational data, that it’s okay to use the direct oral anticoagulants.”
— Dr. Jori May [56:53]

10. DOAC Reversibility

• Annual debate topic. Warfarin is more reversible, but DOACs have lower major bleeding risk to begin with.
• DOAC reversal agents do exist (andexanet alfa for Xa inhibitors, idarucizumab for dabigatran), but their availability and bleeding outcomes are debated; not all centers have access ([61:59]).

Notable Quotes & Memorable Moments

• On plant care vs. medicine:
  “With plants, you do this and the plant grows, or you don’t do this and the plant does not grow. I find it really satisfying in a strange way.”
  — Dr. Jori May [04:17]

• Grandfatherly advice:
  “It’s very easy to get caught up in the path of medicine… my grandfather encouraged me to find what I enjoyed at each stage and let that guide my decisions.”
  — Dr. Jori May [05:55]

• Summing up the challenge:
  “Hematology is this imperfect balance of bleeding and clotting and how to strike that balance.”
  — Dr. Jori May [29:06]

• On the difficulty of these cases:
  “Hopefully folks listening feel a little bit more equipped to encounter these really challenging cases. But hopefully just a therapy session to say it’s hard and we all feel you.”
  — Dr. Jori May [65:43]

Timestamps for Key Segments

• Defining Anticoagulation Failure — [11:05]
• Assessing DOAC Adherence & Dose — [11:48], [18:22]
• Anti-Xa Levels & Lab Testing — [20:29]
• Imaging Clot Chronicity & Radiology Collaboration — [33:37]
• DOACs in Special Populations (Obesity, Renal Failure, Anatomy) — [25:56], [28:44]
• Switching, Holding, or Dose-Adjusting Agents — [44:44], [47:01], [50:48]
• DOACs for LV Thrombus & Unusual Clot Locations — [56:53]
• Agent Reversibility — [61:59]
• Final Take-Home Pearls — [64:07]

Take-Home Points

• Confirm true anticoagulant failure before changing therapy—verify dosing, adherence, and that it’s a genuinely new clot.
• Use DOACs for most VTE and AF patients, including those with renal dysfunction and obesity, but pause at extremes.
• Don’t reflexively switch to warfarin; consider pill burden, patient-specific factors, and broader clinical context.
• For recurrent events, look for anatomical or acquired hypercoagulability.
• Warfarin is mainly indicated for antiphospholipid syndrome (with full criteria), mechanical valves, and pregnancy/breastfeeding.
• Use enoxaparin for temporary coverage if there is genuine uncertainty or until more information is available.
• Direct communication with radiology and pharmacy is essential in complex VTE/anticoagulation cases.

This episode is a must-listen for hospitalists and internal medicine clinicians seeking clarity—and peace of mind—when facing inpatient DOAC dilemmas.