External Compression Therapy for Secondary Prevention of Lower-Limb Loss and Cardiovascular Mortality

Overview

In this clinical research study the investigators will test the efficacy of an innovative, non-invasive methodology to reduce mortality and lower limb loss among high-risk medically-underserved patients with cardiovascular disease in North Philadelphia. Patients with cardiovascular disease and recent lower limb amputation will be treated with an intermittent compression device on the remaining lower limb to prevent dual amputation. The study hypothesis is that the study intervention will protect against further lower limb-loss/death and reduce cardiovascular mortality in these patients (one year effect against limb-loss/death). This study may result in better secondary prevention strategies for disadvantaged urban populations as well as the general population.

The purpose of this study is to evaluate whether a non-invasive intervention for 3 months with an intermittent compression device (ArtAssist®) in a high risk patient group reduces the risk of subsequent one-year limb-loss and/or death (e.g. one-year amputation-free survival and overall survival.) Survival after an amputation is markedly decreased due to generalized cardiovascular disease. The thirty-day mortality after amputation ranges from 6% to 16% depending on renal function. Two-year mortality after amputation is up to 40%.For dialysis patients, two year mortality was 58%.13 The five-year mortality after amputation in non-renal patients is 65%, while in dialysis patients five-year mortality is 83%. Patients who have undergone a major lower extremity amputation related to vascular disease are also at increased risk for losing their remaining lower extremity. The loss of the second lower extremity has a more profound impact on patients' ability to ambulate or function independently than the first amputation. Despite intensive initial rehabilitation, the use of prosthetics in bilateral amputees decreases rapidly over time. Contra-lateral amputations occur in up to 33%, after a mean of eight months. According to another study, 17% of diabetic initial amputees become bilateral amputees after a median time of less than one year for men and less than two years for women. According to a 2013 study, the majority of the subsequent contra-lateral amputations occur in the first year after the index amputation. We hope to prove that that there is a role for IPC in vascular patients at high-risk for mortality and limb-loss with relatively low-cost compression therapy. We hope to learn more about which underserved patient categories are most likely to benefit from this and when to start the intervention.