Management of Patients with Elevated Pulmonary Vascular Resistance and Low Ankle-Brachial Index

Diagnosis and Assessment

The American College of Cardiology recommends Ankle-Brachial Index (ABI) assessment to diagnose peripheral arterial disease (PAD), where ABI ≤0.90 confirms PAD diagnosis, and ABI values should be reported as abnormal (≤0.90), borderline (0.91-0.99), normal (1.00-1.40), or noncompressible (>1.40) 1, 2, 3, 4
For noncompressible vessels, toe pressure/toe-brachial index (TBI) with waveforms should be performed, and TBI is preferred in dialysis patients as ABI might be falsely elevated due to vascular calcification 1, 5
Segmental leg pressures with pulse volume recordings (PVR) and Doppler waveforms can help delineate the anatomic level of PAD, and duplex ultrasound is recommended as the first-line imaging method to confirm PAD lesions 1, 4
Consider right heart catheterization for definitive PVR measurement in severe cases, and maintain systemic vascular resistance (SVR) greater than pulmonary vascular resistance (PVR) 6

ACE inhibitors or ARBs are recommended for blood pressure control and cardiovascular risk reduction, with a Class I recommendation 5
Cilostazol is recommended as the medication of choice for patients with intermittent claudication, with a Class I recommendation for improving symptoms and increasing walking distance in PAD patients with claudication, at a dosage of 100 mg orally twice daily, but is contraindicated in patients with heart failure 2
Antiplatelet therapy, such as aspirin (75-325 mg daily) or clopidogrel (75 mg daily), is recommended for PAD patients, with clopidogrel potentially preferred over aspirin 3, 7
Statin therapy is recommended for all PAD patients, with a Class I recommendation and an LDL-C target <1.4 mmol/L (<55 mg/dL) or reduction by ≥50% 3, 8, 4
Supervised exercise training for a minimum of 30-45 minutes, at least 3 times weekly for 12+ weeks, is recommended to complement medication therapy and improve outcomes 2

Duplex ultrasound is recommended as the first-line imaging technique, followed by CTA and/or MRA as adjuvant imaging techniques for preparation of revascularization procedures 4
For aortoiliac disease, consider catheter-directed stent placement, and for critical limb ischemia, urgent revascularization may be necessary 9, 1
Assemble a multi-disciplinary team including surgeons and cardiac anesthesiologists for surgical cases, and consider perioperative risks related to elevated PVR, especially in patients requiring surgery for PAD 6

Periodic recording of ABIs for synthetic grafts, and duplex imaging for vein grafts to detect reduced flow, are recommended for follow-up 10
Use TBI rather than ABI for PAD diagnosis in dialysis patients, and careful patient selection for revascularization is necessary as outcomes after revascularization for PAD in dialysis patients are inferior 5
Maintain systemic vascular resistance greater than pulmonary vascular resistance to prevent right ventricular ischemia in critical care settings, and consider inhaled nitric oxide for acute management of elevated PVR in critical care settings 6
Regular follow-up is necessary to assess symptom improvement and medication tolerance, with monitoring for side effects such as headache, diarrhea, dizziness, and palpitations 2