What is the recommended treatment approach for a patient with elevated Pulmonary Vascular Resistance (PVR) and a low Ankle-Brachial Index (ABI)?

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

Diagnostic Assessment

For patients with elevated Pulmonary Vascular Resistance (PVR) and low Ankle-Brachial Index (ABI), a comprehensive multidisciplinary approach focusing on both conditions is essential, as both conditions significantly impact morbidity, mortality, and quality of life.

Confirming Diagnosis:

1. ABI Assessment:

   • ABI ≤0.90 confirms peripheral arterial disease (PAD) diagnosis 1
   • Report ABI as abnormal (≤0.90), borderline (0.91-0.99), normal (1.00-1.40), or noncompressible (>1.40) 1

2. For Noncompressible Vessels:

   • Toe pressure/toe-brachial index (TBI) with waveforms should be performed when ABI >1.40 1
   • In dialysis patients, TBI is preferred as ABI might be falsely elevated due to vascular calcification 1

3. Additional PAD Assessment:

   • Segmental leg pressures with pulse volume recordings (PVR) and Doppler waveforms to delineate anatomic level of PAD 1
   • Duplex ultrasound as first-line imaging method to confirm PAD lesions 1

4. PVR Assessment:

   • Echocardiography to measure PVR using tricuspid regurgitant velocity to RVOT velocity-time integral ratio 2
   • Consider right heart catheterization for definitive PVR measurement in severe cases 1

Treatment Approach

Medical Management:

1. Antiplatelet Therapy:

   • Aspirin (75-325 mg daily) or clopidogrel (75 mg daily) is recommended for all PAD patients, with clopidogrel potentially preferred over aspirin 3
   • Warfarin is explicitly contraindicated for PAD treatment due to increased risk of major bleeding 3

2. Statin Therapy:

   • High-intensity statin therapy for all PAD patients with LDL-C target <55 mg/dL or reduction by ≥50% 3

3. For Claudication Symptoms:

   • Cilostazol 100 mg twice daily (contraindicated in heart failure) 3
   • Supervised exercise training program for 30-45 minutes, at least 3 times weekly for 12+ weeks 3, 1

4. Blood Pressure Management:

   • ACE inhibitors or ARBs for blood pressure control and cardiovascular risk reduction 1
   • Maintain systemic vascular resistance (SVR) greater than pulmonary vascular resistance (PVR) 1

5. Pulmonary Vasodilators:

   • For elevated PVR, consider pulmonary vasodilator therapy to reduce PVR and improve right ventricular function 4
   • Reduction in PVR is associated with improvements in both right and left ventricular function 4

Revascularization Considerations:

1. For PAD:

   • Duplex ultrasound as first-line imaging, followed by CTA and/or MRA as adjuvant imaging techniques for preparation of revascularization procedures 1
   • For aortoiliac disease, consider catheter-directed stent placement 1
   • For critical limb ischemia, urgent revascularization may be necessary 1

2. Multidisciplinary Approach:

   • For surgical cases, assemble a multi-disciplinary team including surgeons and cardiac anesthesiologists 1
   • Consider perioperative risks related to elevated PVR, especially in patients requiring surgery for PAD 1

Monitoring and Follow-up

1. Regular ABI Monitoring:

   • Periodic recording of ABIs for synthetic grafts 1
   • Duplex imaging for vein grafts to detect reduced flow 1

2. PVR Monitoring:

   • Regular echocardiographic assessment of PVR and right ventricular function 4, 2
   • Monitor for improvement in PVR with therapy, which correlates with improved outcomes 4

3. Cardiovascular Risk Assessment:

   • Regular assessment of cardiovascular risk factors and events, as elevated PVR predicts mortality, heart failure hospitalization, and adverse cardiovascular events 2

Special Considerations

1. For Dialysis Patients:

   • Use TBI rather than ABI for PAD diagnosis 1
   • Careful patient selection for revascularization, as outcomes after revascularization for PAD in dialysis patients are inferior 1

2. For Critical Care Settings:

   • Maintain systemic vascular resistance greater than pulmonary vascular resistance to prevent right ventricular ischemia 1
   • Consider inhaled nitric oxide for acute management of elevated PVR in critical care settings 1

The management of patients with both elevated PVR and low ABI requires addressing both conditions simultaneously to reduce cardiovascular risk, improve symptoms, and prevent complications. A multidisciplinary approach involving vascular specialists, cardiologists, and other relevant specialists is essential for optimal outcomes.