Importance of Walking in the Peripheral Arterial Disease Patient’s Shoes

The conundrums of classifying peripheral arterial disease severity
Atherosclerotic vascular disease manifests as various clinical syndromes depending on the vascular bed, plaque vulnerability and stenosis severity. In lower extremity peripheral arterial disease (PAD), patients with chronic obstructive disease are frequently asymptomatic but at risk for adverse cardiovascular events including myocardial infarction and mortality (1). In these patients, guideline directed medical therapies lower cardiovascular risk. In patients that are symptomatic, however, the goals are two-fold, and include relief of pain and disease associated limitations. Although there are objective measures of disease severity such as the ankle brachial index and clinical classification schema such as the Rutherford scoring system, the hemodynamic and physician determined assessments are poorly correlated with patient reported health status (2). For clinical care focused on improving physical functioning and quality of life (QoL), such as with elective endovascular revascularization or supervised exercise for PAD, we often rely on clinical history as a measure of efficacy of the therapy. Qualitative assessments, such as standardized questionnaires, offer tremendous advantage in these settings and have been used widely in research.

There are several validated instruments used to assess QoL and functional status in PAD and changes in response to specific therapies. These tools, which capture patient reported outcomes, termed PROMs, are not routinely administered in the clinical care of patients with PAD. With pressure from Centers for Medicare & Medicaid Services (CMS) and other organizations promoting value in healthcare and patient centered care, the uptake of PROMs in cardiovascular disease is forthcoming (3). In fields such as orthopedic surgery, PROMs for numerous musculoskeletal disorders have been standard in clinical care for years and have already been incorporated into CMS Merit-Based Incentive Payment System programs (4). When a PROM is designated as a performance measure (PROM-PM) it signifies an external mandate for collecting the data in clinical practice. The current American Heart Association statement is timely and a critical step towards unifying vascular disease specialists and key stakeholders on the effort to introduce PAD PROM-PMs as benchmarks of quality.

Getting the basics down on PAD PROMs
The process for selection of candidate PROMs is clearly articulated and a compendium of disease-specific single domain, disease-specific multi-dimensional, and generic instruments are recommended for patients with claudication. Taking lessons from studies examining barriers to completion of surveys, the authors appropriately selected questionnaire that are concise and understandable (5). Other important aspects considered included validity, availability of population norms and responsiveness; including an understanding of minimum clinically important differences (threshold changes that are associated with a clinical, rather than a statistical numerical difference) (6). The timing of PROM administration is suggested at baseline and follow-up intervals after therapies have been initiated. Considerations not tackled include how many PROMs to simultaneously administer and how to prioritize among the PROMs proposed. These issues will surely work themselves out, with a likely path of an option for selection based on the local patient population or in response to specific therapies being considered.

Roadblocks and solutions for PROM implementation
For PROMs to be used for medical decision making, local and national registries, performance measures, incentive programs, risk stratification and modeling, and be available to patients and the potentially the public, they must be systematically collected, reported in an electronic form, and integrated into the electronic health record. There have been numerous studies assessing PROM collection methods including paper forms, apps (phone or tablet), and Web-based. In a systematic review of 32 studies of electronic PROMs, Web-based systems where the most common (81%) and advantages included higher data quality and response rates and facilitated symptom management and patient-clinical communication. The drawbacks were not surprising and centered on high initial financial investment, privacy, and the digital divide (7). If the financial and time burdens of PROM software and support for data collection fall to institutions and providers without providing revenue, it will stress hospital budgets and increase provider burnout. The document touches on these issues and as a society we must address them. Some proposals for lowering the burdens include use of PROMs in the public domain that do not require licensing, using established registries for collection and reporting of questionnaires, allowing private companies to collect and report data to practices and CMS. Efforts are already underway by the National Institutes of Health, which funded a person-centered measures database called PROMIS and the American College of Cardiology which offers the Seattle Anginal and Rose questionnaires as optional sections on the Cath PCI Registry data collection form (8).

Overall, there is strong rationale and precedent to move forward with PROMs to improve PAD quality care and outcomes. Future applications of the metrics include modeling to examine heterogeneous response to therapies and predictors of adverse events such as limb events and readmission.