The Merits of Supervised Exercise in Critical Limb Ischemia

Hello, and welcome to the May 2019 issue of Vascular Disease Management. There are many interesting manuscripts and case reports in this issue. I have chosen to comment on a submission by Fahad Younas, MD, and R. Kevin Rogers, MD, on “Supervised Exercise in Critical Limb Ischemia.”

I have chosen to comment on this article as supervised exercise has gained widespread acceptance in the treatment of patients presenting with claudication, but there has been much less utilization of this therapy in patients presenting with critical limb ischemia (CLI). As pointed out by the authors, standard supervised exercise programs for treating claudicants may be inappropriate in patients presenting with CLI, as standard exercise algorithms may apply pressure at sites of healing wounds or ulcers, possibly limiting healing. Alternative exercise regimens such as cycling, strength training, and upper arm ergometry may be more appropriate in CLI. Ultimately, enabling patients to simply walk may represent success in the CLI cohort of patients. If major amputation is required, improved overall strength may enable subsequent ambulation with a prosthesis, a goal that is often not attained in CLI patients who require major amputation secondary to ischemic vascular disease. Despite significant advances in revascularization and wound healing, CLI is still associated with high overall mortality, profound morbidity, and high medical expenditure.

Studies of supervised exercise therapy in claudicants have suggested multiple potential mechanisms resulting in clinical improvement, but these have not been studied in CLI. Potential listed mechanisms include:

1)Impact on inflammatory markers such as fibrinogen, serum amyloid protein, and C-reactive protein. Supervised exercise decreased these markers at one year;

2) Improved endothelial function;

3) Increased capillary density;

4) Altered skeletal muscle metabolism;

5) Improvement in walking economy;

6) Improvement in blood rheology; 

Improving overall strength would likely result in psychological and physical benefits post revascularization in CLI patients who typically experience profound depression and poor physical conditioning. 

Many questions remain unanswered. Will supervised exercise therapy in CLI patients result in better survival, less morbidity, and increased quality of life? Will it lead to less reintervention? Is it cost effective? Will supervised exercise therapy gain widespread acceptance and ultimately reimbursement in CLI patients? These are questions that will need to be answered. 

I am intrigued by this article and its possible implications. I have not utilized supervised exercise therapy in patients presenting with CLI, pre- or post-revascularization, but I think there may be merit to this approach. Clearly there has been benefit demonstrated in claudicants, but this cohort of patients is quite different. I plan to incorporate this into my practice and personally evaluate the merits of this strategy.