The USA amputates more legs every year than all legs amputated since the civil war.
That was the comment that got the attention of the panel during the Medicare Evidence Development and Coverage Advisory Committee (MEDCAC) meeting for Lower Extremity Peripheral Artery Disease (PAD) this past July.
The meeting examined the scientific evidence of existing interventions (medical therapy, exercise training, and revascularization) in the treatment of lower extremity PAD. Since PAD exists on a continuum, the evidence was presented for patients who are asymptomatic but have PAD; those with lower extremity pain during exertion, also known as intermittent claudication (IC); and those with critical limb ischemia (CLI), which is the most severe form of PAD and if left untreated leads to those amputations referenced by the comment. The meeting brought together the top physicians and scientists from around the US studying PAD, representing medical societies, world-class hospitals and institutes, and industry.
As someone who covers the markets for devices that treat PAD, I was surprised by some of the data presented; here are some that stood out for me:
- PAD is not only a disease that affects over 65-year old Caucasian males. Several presenters commented on the fact the women with PAD present at a later age and suffer higher rates of amputations. Furthermore, Hispanics and African-Americans have higher rates of CLI, which may be associated with their higher rates of diabetes when compared to Caucasians. One presenter went as far as saying that the CLI population is essentially a diabetic population.
- One in every 20 American over the age of 50 has PADthis jumps to approximately one in 5 for Medicare patientsyet 74% are not aware of PAD. This awareness pales in comparison with other diseases such as Multiple Sclerosis, Lou Gehrigs Disease and Cystic Fibrosis, all of which have higher rates of awareness but only a fraction of the prevalence. PAD patients are also undertreated compared to those with coronary artery disease and are less likely to recall a physician advising them to exercise. They are less likely to be on cholesterol lowering medications or even aspirin. This leads to increased hospitalization costs as the disease progresses from asymptomatic to CLI, and results in a heavy economic burdenestimated to be about $21 billion/annuallythat could be lowered by intervening earlier in the progression of the disease.
- There is large variability in the rates of revascularization across the US, which corresponds with varying rates of limb amputations; regions with low revascularization rates have higher rates of limb amputation and vice versa. Interestingly, a recent study observed a strong relationship between lower socioeconomic status and a higher prevalence of PAD and recommended targeted awareness efforts towards lower socioeconomic subpopulations in the US.
- Italy has the lowest rate of limb amputation due to CLI in the world. Only three high-volume hospitals perform these procedures. They implement a co-operative approach bringing in different physician specialties at different stages of treatment; they take a very aggressive endovascular approach to treating CLI and they are at the fore-front of using new technologies to treat CLI.
- The cost burden of CLI is huge, estimated at almost $11 billion/year in the US, with Medicare and Medicaid paying for 80% of the bill. In fact, it is the sixth most expensive surgical procedure in the US. There are currently 2 million people suffering from CLI in the US and of those that have a limb amputation, the majority will not receive an interventional procedure before amputation.
After listening to over 20 presentations the committee then voted on their confidence in the scientific evidence presented that day. Their findings and recommendations will in turn be used by the Centers for Medicare and Medicaid Services (CMS) as a guide when deciding on reimbursement decisions related to PAD. Here is what they decided:
For asymptomatic patients, the committee was not convinced that any sort of intervention, except lifestyle changes, improved health outcomes. For patients with IC, there was moderate support for intervention, with exercise being the primary option and revascularization only when this failed. However, there was overwhelming endorsement of intervention with CLI. Here, the panel was convinced that intervention in the form of revascularization is necessary given the severity of the disease and heavy cost burden associated with current treatment options.
If only to make the panels choices much harder, an interesting point was made by several presenters, especially those representing industry; mainly that there have been huge advancements in medical devices used in revascularization procedures in the past few years. This trend is expected to continue as close to 9,000 patients are currently enrolled in clinical studies investigating endovascular therapies, with 2/3 of the trials focusing on both IC and CLI. Therefore, the committees recommendations may require an update in a couple of years as these devices show their superior efficacy in treating PAD.