Non-Invasive Physiologic Evaluation of Peripheral Arterial Disease

ABSTRACT Peripheral Arterial Disease (PAD) is a substantial healthcare burden in the US (estimated andgt; 8M) and around the world (estimated andgt; 200M). In the aging population, over 24% with age andgt; 80 years have PAD. 50% of all patients with PAD are asymptomatic, and up to 40% of the remaining patients have atypical symptoms. The conventional ankle/brachial index (cABI) ratio is established as the initial diagnostic evaluation in symptomatic patients presenting for PAD evaluation, with high sensitivity and specificity. Unfortunately, the sensitivity falls off substantially when applied to asymptomatic/atypical patients and the use of cABI as a screening test is highly controversial. The USPSTF recommendations are in conflict with cardiovascular medical specialty society guidelines. Therefore, an improved approach to evaluating these asymptomatic/atypical subsets of PAD patients is an unmet need in healthcare, and the solution is an important quality opportunity. The STTR Phase I (R43HL133633-01A1) results, and preliminary data for a submitted SBIR (R43HL146579- 01, pending resubmission), are driving a unique approach to meeting this healthcare need. Recent data suggest that the fall off in sensitivity is related to the physiologic changes in end-organ tissues due to co- morbidities and risk factors. The SBC RFPi, Inc. proposes to integrate non-invasive, non-contact systolic blood pressure threshold determination  ABI ratio (Phase I) with peripheral oxygen determination (SBIR), with further integration into RFPi’s novel imaging technology solution Multi-spectral Physiologic Visualization (MSPV) (first form factor FDA approved 12/14/18). MPSV non-invasively (no dyes or ionizing radiation) and without patient contact analyzes and displays blood flow distribution physiology (flow in vessels and perfusion in tissues) in target tissues in true real-time. This 3-factor integration product, called MSPVO2-ABI, will provide the physiologic data augmentation needed to improve sensitivity in the evaluation testing of asymptomatic/atypical patients with PAD. In this Phase II proposal, Specific Aim #1 will test and integrate hardware and software specifications for these 3 factors. In Specific Aim #2, the RFPi Product Development Team will design, engineer, build, test, and validate pre-clinical and clinical prototypes built to ISO 1345 and CRF 820 GMP standards. In Specific Aim #3 the clinical prototypes will be evaluated in the proof-of-concept Clinical Testing Study in PAD (CTS-PAD) at two Vascular Surgery Clinics in the US. The final product from this Phase II proposal will be the engineering design for the 510k FDA Class II submission and for CMS reimbursement studies as outlined in the Commercialization Plan. RFPi, Inc., will bring the MPSVO2-AVI product to healthcare providers to meet this unmet need in PAD care.NARRATIVE Peripheral Arterial Disease (PAD) affects over 8M people in the US, 24% of people over age 80 years, and can often result in amputation. An improved approach to evaluating patients with PAD is needed, since the majority of patients have atypical or absent symptoms of the disease. RFPi, Inc. has developed a unique imaging- based solution that combines anatomic and physiologic information to better evaluate these PAD patients with atypical or absent symptoms.