Peripheral arterial disease - Emerging treatments

Therapeutic angiogenesis

Therapeutic angiogenesis (administration of vascular growth factors) has emerged as a possible alternative treatment for peripheral arterial disease (PAD). Preliminary evidence suggests that autologous bone marrow mononuclear cells implantation in PAD patients with critical limb ischaemia may improve lower limb ischaemic symptoms.[94][95] This is also supported by the results of two systematic reviews.[96][97] However, further data from larger studies are required before reaching any firm conclusions.

Balloon catheter

The US Food and Drug Administration (FDA) approved the Lutonix® 035 drug-coated balloon percutaneous transluminal angioplasty (PTA) catheter, the IN.PACT Admiral® paclitaxel-coated PTA balloon catheter, and the Stellarex® drug-coated angioplasty balloon for the treatment of femoropopliteal lesions.[98][99][100][101] These drug-coated balloons may improve long-term angioplasty outcomes. However, one Cochrane review found that current evidence is insufficient to prove this.[102] [ ] Furthermore, one meta-analysis found a signal for increased mortality in patients treated with paclitaxel-coated balloons and stents.[103] This has led the FDA to issue a warning advising that patients who have been treated with these devices should be diligently monitored, and that clinical studies should continue.[104] In the UK, the Medicines and Healthcare products Regulatory Agency (MHRA) advises that, where indicated, paclitaxel-coated devices (PCDs) can be considered a treatment option in patients with critical limb ischaemia or intermittent claudication. Previous MHRA advice relating to the use of the lowest-dose PCDs available and to avoid/reduce repeated exposure of PCDs is withdrawn.[105]

Vorapaxar

Vorapaxar is a protease-activated receptor-1 (PAR-1) antagonist that acts as a potent antiplatelet agent. In clinical trials that included patients with recent myocardial infarction or PAD, the addition of vorapaxar on a background of aspirin and/or clopidogrel was associated with a reduction in major adverse cardiovascular events during long-term follow-up. A subgroup analysis of patients with PAD also suggested that vorapaxar was associated with a reduction in acute limb ischaemia.[106] Vorapaxar is approved by the FDA for the reduction of thrombotic cardiovascular events in patients with a history of PAD.

Intravascular lithotripsy

Intravascular lithotripsy is a technique that involves using pressure waves to soften arterial plaque in calcified peripheral arterial disease, which may have benefit in selected patients with calcified arteries.[107][108] Further studies are needed.[109]