Understanding "Normal" Arterial Doppler with TBI Discrepancy
Your provider likely reported the arterial Doppler as "normal" because both your left and right toe-brachial index (TBI) values were above 0.70, which is the diagnostic threshold for peripheral artery disease (PAD), even though there was a discrepancy between sides. 1
Why the Study Was Called Normal
- A TBI >0.70 is considered normal and excludes significant PAD, regardless of side-to-side differences 1
- The European Society of Cardiology guidelines specify that TBI or duplex ultrasound is indicated when ankle-brachial index (ABI) is elevated (>1.40), suggesting your provider was appropriately using TBI to assess for arterial disease 1
- Duplex ultrasound is recommended as the first-line imaging method to assess anatomy and hemodynamic status of lower extremity arteries, and if both sides showed adequate perfusion (TBI >0.70), this would be interpreted as "normal" from a PAD diagnostic standpoint 1
Important Context for Your Specific Situation
The Discrepancy May Still Be Clinically Relevant
- While both TBIs may be above the PAD threshold, a significant left-right difference could indicate early arterial disease or asymmetric atherosclerosis that hasn't yet reached diagnostic thresholds 1
- Given your multiple cardiovascular risk factors (CKD stage 2, mild fatty liver disease, grade 1 diastolic dysfunction, iron deficiency anemia, low stroke volume index), you are at very high cardiovascular risk and warrant closer monitoring 1
Your Anticoagulation Status
- You are appropriately anticoagulated with apixaban 5 mg twice daily for your DVT history 2, 3
- For patients with CKD stage 2 (eGFR 60-89 mL/min), no dose adjustment of apixaban is needed, and the 5 mg twice daily maintenance dose is correct after completing the initial 7-day period of 10 mg twice daily 3
- The dose should NOT be reduced to 2.5 mg twice daily unless you have completed at least 6 months of full-dose therapy and are transitioning to extended secondary prevention 2, 3
Why This Matters for You
- Patients with diabetes and cardiovascular disease should have yearly screening with clinical assessment and/or ABI measurement 1
- In patients with symptomatic lower extremity artery disease (LEAD) without high bleeding risk, a combination of low-dose rivaroxaban (2.5 mg twice daily) and aspirin (100 mg once daily) should be considered 1
- However, you are already on full-dose apixaban for DVT, which takes precedence over PAD-specific antiplatelet/anticoagulation strategies 2, 4
What You Should Discuss With Your Provider
- Request the actual TBI values for both left and right sides to understand the magnitude of the discrepancy 1
- Ask whether the difference warrants follow-up imaging or repeat testing in 6-12 months, especially given your cardiovascular risk profile 1
- Clarify whether your CKD stage 2 diagnosis was based on a single eGFR measurement or confirmed with repeat testing, as transient reductions can occur 1
- Discuss whether your iron deficiency anemia has been adequately treated, as severe anemia can contribute to cardiovascular complications and even ischemic events 5, 6
Critical Pitfalls to Avoid
- Do not stop or reduce your apixaban dose without explicit instruction from your provider, as you require full anticoagulation for DVT secondary prevention 2, 3
- Avoid NSAIDs, as they substantially increase bleeding risk when combined with anticoagulants and can worsen kidney function 1, 2, 4
- Your grade 1 diastolic dysfunction, while mild, can be associated with elevated left ventricular end-diastolic pressure even when mean left atrial pressure is normal, so cardiac symptoms should be reported promptly 7, 8