Personalizing Care for Peripheral Arterial Disease Patients

PAD increases the risk of stroke, cardiovascular death, myocardial infarction, coronary artery disease and cerebrovascular disease. PAD management includes pharmacological treatments and revascularization of blood vessels. Percutaneous vascular intervention (PVI)—a minimally invasive procedure that is attempted to unblock occluded arteries. In cases of impenetrable plaques, PVI has led to worsened secondary bypass outcomes and amputation.

PAD symptoms are related to the blood flow being restricted due to blockages inside the arteries. Blockages result from the build-up of fatty deposits or plaque and can be hard (calcium and dense collagen) or soft. Appropriate interventional strategies for blood flow restoration are critical to prevent amputation and death.

There are a couple of anatomic scores for PAD that indicate if a lesion or a patient will be better served by endovascular treatment or an open bypass. These scores are based on the length and degree of stenosis. While the aforementioned do not provide any details about what the occlusion is made of. Soft lesions (whether long or short) can be recanalized using endovascular procedures whereas hard lesions are impenetrable. “As identified in this case, atheromatous plaques composed of dense collagen are missed on preoperative imaging. Consequent decisions to perform PVI often result in failure as dense collagen lesions are difficult to penetrate with guidewire. MRI histology with UTE and T2W sequences can distinguish between soft plaque and hard plaque composed of calcium and dense collagen. This novel imaging technique offers a comparative edge in detecting PVI failures and selecting patients suited better for PVI versus open surgery in advance,” Roy said. With the advent of new sophisticated MRI scanners, researchers now have access to refined methods because of the availability of a wide array of sequences (in addition to UTE and T2W) and material equipment. Roy added, “PAD is a real epidemic, and it is growing along with diabetes and renal failure. Our understanding of PAD is quite poor and the imaging techniques that we use have been the same for decades. So, having the ability to be advanced with how we're diagnosing PAD, and tailoring our treatment can help patient outcomes, particularly because there's a big spectrum to what the blockages can be made of. MRI histology is a good tool to shed light on what these blockages are composed of and thereby predict endovascular failure. Right now, our outcomes are quite poor and we're having to intervene on these patients again and again, each time more futile than the last. We hope that by being able to image and understand what we're treating, we have a better understanding of how to treat individual patients so that they have the best possible outcomes.”