Trends of Concomitant Diabetes and Peripheral Artery Disease and Lower Extremity Amputation in US Medicare Patients, 2007 to 2019.

BACKGROUND: Previous studies demonstrate geographic and racial/ethnic variation in diagnosis and complications of diabetes and peripheral artery disease (PAD). However, recent trends for patients diagnosed with both PAD and diabetes are lacking. We assessed the period prevalence of concurrent diabetes and PAD across the United States from 2007 to 2019 and regional and racial/ethnic variation in amputations among Medicare patients. METHODS: Using Medicare claims from 2007 to 2019, we identified patients with both diabetes and PAD. We calculated period prevalence of concomitant diabetes and PAD and incident cases of diabetes and PAD for every year. Patients were followed to identify amputations, and results were stratified by race/ethnicity and hospital referral region. RESULTS: 9 410 785 patients with diabetes and PAD were identified (mean age, 72.8 [SD, 10.94] years; 58.6% women, 74.7% White, 13.2% Black, 7.3% Hispanic, 2.8% Asian/API, and 0.6% Native American). Period prevalence of diabetes and PAD was 23 per 1000 beneficiaries. We observed a 33% relative decrease in annual new diagnoses throughout the study. All racial/ethnic groups experienced a similar decline in new diagnoses. Black and Hispanic patients had on average a 50% greater rate of disease compared with White patients. One- and 5-year amputation rates remained stable at ≈1.5% and 3%, respectively. Native American, Black, and Hispanic patients were at greater risk of amputation compared with White patients at 1- and 5-year time points (5-year rate ratio range, 1.22-3.17). Across US regions, we observed differential amputation rates, with an inverse relationship between the prevalence of concomitant diabetes and PAD and overall amputation rates. CONCLUSIONS: Significant regional and racial/ethnic variation exists in the incidence of concomitant diabetes and PAD among Medicare patients. Black patients in areas with the lowest rates of PAD and diabetes are at disproportionally higher risk for amputation. Furthermore, areas with higher prevalence of PAD and diabetes have the lowest rates of amputation.

Using a cohort study of diabetes and peripheral artery disease to compare logistic regression and machine learning via random forest modeling.

BACKGROUND: This study illustrates the use of logistic regression and machine learning methods, specifically random forest models, in health services research by analyzing outcomes for a cohort of patients with concomitant peripheral artery disease and diabetes mellitus. METHODS: Cohort study using fee-for-service Medicare beneficiaries in 2015 who were newly diagnosed with peripheral artery disease and diabetes mellitus. Exposure variables include whether patients received preventive measures in the 6 months following their index date: HbA1c test, foot exam, or vascular imaging study. Outcomes include any reintervention, lower extremity amputation, and death. We fit both logistic regression models as well as random forest models. RESULTS: There were 88,898 fee-for-service Medicare beneficiaries diagnosed with peripheral artery disease and diabetes mellitus in our cohort. The rate of preventative treatments in the first six months following diagnosis were 52% (n = 45,971) with foot exams, 43% (n = 38,393) had vascular imaging, and 50% (n = 44,181) had an HbA1c test. The directionality of the influence for all covariates considered matched those results found with the random forest and logistic regression models. The most predictive covariate in each approach differs as determined by the t-statistics from logistic regression and variable importance (VI) in the random forest model. For amputation we see age 85 + (t = 53.17) urban-residing (VI = 83.42), and for death (t = 65.84, VI = 88.76) and reintervention (t = 34.40, VI = 81.22) both models indicate age is most predictive. CONCLUSIONS: The use of random forest models to analyze data and provide predictions for patients holds great potential in identifying modifiable patient-level and health-system factors and cohorts for increased surveillance and intervention to improve outcomes for patients. Random forests are incredibly high performing models with difficult interpretation most ideally suited for times when accurate prediction is most desirable and can be used in tandem with more common approaches to provide a more thorough analysis of observational data.

Epidemiology and Risk of Amputation in Patients With Diabetes Mellitus and Peripheral Artery Disease.

Peripheral artery disease (PAD) stems from atherosclerosis of lower extremity arteries with resultant arterial narrowing or occlusion. The most severe form of PAD is termed chronic limb-threatening ischemia and carries a significant risk of limb loss and cardiovascular mortality. Diabetes mellitus is known to increase the incidence of PAD, accelerate disease progression, and increase disease severity. Patients with concomitant diabetes mellitus and PAD are at high risk for major complications, such as amputation. Despite a decrease in the overall number of amputations performed annually in the United States, amputation rates among those with both diabetes mellitus and PAD have remained stable or even increased in high-risk subgroups. Within this cohort, there is significant regional, racial/ethnic, and socioeconomic variation in amputation risk. Specifically, residents of rural areas, African-American and Native American patients, and those of low socioeconomic status carry the highest risk of amputation. The burden of amputation is severe, with 5-year mortality rates exceeding those of many malignancies. Furthermore, caring for patients with PAD and diabetes mellitus imposes a significant cost to the healthcare system-estimated to range from $84 billion to $380 billion annually. Efforts to improve the quality of care for those with PAD and diabetes mellitus must focus on the subgroups at high risk for amputation and the disparities they face in the receipt of both preventive and interventional cardiovascular care. Better understanding of these social, economic, and structural barriers will prove to be crucial for cardiovascular physicians striving to better care for patients facing this challenging combination of chronic diseases.

Call to Action to Prevent Venous Thromboembolism in Hospitalized Patients: A Policy Statement From the American Heart Association.

Venous thromboembolism (VTE) is a major preventable disease that affects hospitalized inpatients. Risk stratification and prophylactic measures have good evidence supporting their use, but multiple reasons exist that prevent full adoption, compliance, and efficacy that may underlie the persistence of VTE over the past several decades. This policy statement provides a focused review of VTE, risk scoring systems, prophylaxis, and tracking methods. From this summary, 5 major areas of policy guidance are presented that the American Heart Association believes will lead to better implementation, tracking, and prevention of VTE events. They include performing VTE risk assessment and reporting the level of VTE risk in all hospitalized patients, integrating preventable VTE as a benchmark for hospital comparison and pay-for-performance programs, supporting appropriations to improve public awareness of VTE, tracking VTE nationwide with the use of standardized definitions, and developing a centralized data steward for data tracking on VTE risk assessment, prophylaxis, and rates.

Implementation of Supervised Exercise Therapy for Patients With Symptomatic Peripheral Artery Disease: A Science Advisory From the American Heart Association.

Patients with lower-extremity peripheral artery disease (PAD) have greater functional impairment, faster functional decline, increased rates of mobility loss, and poorer quality of life than people without PAD. Supervised exercise therapy (SET) improves walking ability, overall functional status, and health-related quality of life in patients with symptomatic PAD. In 2017, the Centers for Medicare & Medicaid Services released a National Coverage Determination (CAG-00449N) for SET programs for patients with symptomatic PAD. This advisory provides a practical guide for delivering SET programs to patients with PAD according to Centers for Medicare & Medicaid Services criteria. It summarizes the Centers for Medicare & Medicaid Services process and requirements for referral and coverage of SET and provides guidance on how to implement SET for patients with PAD, including the SET protocol, options for outcome measurement, and transition to home-based exercise. This advisory is based on the guidelines established by the Centers for Medicare & Medicaid Services for Medicare beneficiaries in the United States and is intended to assist clinicians and administrators who are implementing SET programs for patients with PAD.

American Heart Association Principles on the Accessibility and Affordability of Drugs and Biologics: A Presidential Advisory From the American Heart Association.

Net US spending on pharmaceuticals reached $309.5 billion in 2015, an 8.5% increase from the year before, and is expected to reach between $370 and $400 billion by 2020. These current and projected levels have raised serious concerns by policy makers, providers, payers, and patient groups that they are unsustainable and threaten the affordability of and accessibility to much-needed therapies for patients. Two trends related to drugs/biologics and generic drugs/biosimilars underlie this overall increase in spending. First, the market entry prices of innovator pharmaceutical products, or brand drugs and biologics, are at levels that some assessments consider unaffordable to the healthcare system. Second, prices for some established generic drugs such as digoxin and captopril have seen sharp and rapid increases. As an evidence-based patient advocacy organization dedicated to improving the cardiovascular health of all Americans, the American Heart Association has a unique role in advocating for treatments, including medicines that are available, affordable, and accessible to patients. This advisory serves to lay out a set of principles that will guide association engagement in pursuit of this goal.

Alternative causes of myocardial ischemia in women: An update on spontaneous coronary artery dissection, vasospastic angina and coronary microvascular dysfunction.

Although coronary obstruction due to atherosclerosis is the most common cause of myocardial ischemia, a significant proportion of patients have myocardial ischemia in the absence of obstructive epicardial coronary artery disease (CAD). This finding is more common among women and alternative causes can mediate myocardial ischemia. Abnormalities in vascular structure, alterations in coronary vasomotion and dysfunction of the coronary microcirculation can all cause ischemia in the absence of obstructive CAD due to atherosclerosis. In this review, we provide an update on three alternative causes of myocardial ischemia: spontaneous coronary artery dissection (SCAD), vasospastic angina (VSA) and coronary microvascular dysfunction (CMVD). We review pathophysiology, clinical presentation, diagnosis, treatment and outcomes related to these important clinical entities. There is increasing interest in better defining this patient population with use of advanced imaging and testing tools. Despite the increased associated risk with future cardiac events, evidence-based treatments for these diagnoses remain under-studied and poorly defined. These alternative diagnoses should be kept in mind when evaluating women with myocardial ischemia without obstructive CAD due to atherosclerosis.

Design and Rationale of the Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia (BEST-CLI) Trial.

BACKGROUND: Critical limb ischemia (CLI) is increasing in prevalence, and remains a significant source of mortality and limb loss. The decision to recommend surgical or endovascular revascularization for patients who are candidates for both varies significantly among providers and is driven more by individual preference than scientific evidence. METHODS AND RESULTS: The Best Endovascular Versus Best Surgical Therapy for Patients With Critical Limb Ischemia (BEST-CLI) Trial is a prospective, randomized, multidisciplinary, controlled, superiority trial designed to compare treatment efficacy, functional outcomes, quality of life, and cost in patients undergoing best endovascular or best open surgical revascularization. Approximately 140 clinical sites in the United States and Canada will enroll 2100 patients with CLI who are candidates for both treatment options. A pragmatic trial design requires consensus on patient eligibility by at least 2 investigators, but leaves the choice of specific procedural strategy within the assigned revascularization approach to the individual treating investigator. Patients with suitable single-segment of saphenous vein available for potential bypass will be randomized within Cohort 1 (n=1620), while patients without will be randomized within Cohort 2 (n=480). The primary efficacy end point of the trial is Major Adverse Limb Event-Free Survival. Key secondary end points include Re-intervention and Amputation-Free-Survival and Amputation Free-Survival. CONCLUSIONS: The BEST-CLI trial is the first randomized controlled trial comparing endovascular therapy to open surgical bypass in patients with CLI to be carried out in North America. This landmark comparative effectiveness trial aims to provide Level I data to clarify the appropriate role for both treatment strategies and help define an evidence-based standard of care for this challenging patient population. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02060630.

Evidence-Based Policy Making: Assessment of the American Heart Association's Strategic Policy Portfolio: A Policy Statement From the American Heart Association.

BACKGROUND: American Heart Association (AHA) public policy advocacy strategies are based on its Strategic Impact Goals. The writing group appraised the evidence behind AHA's policies to determine how well they address the association's 2020 cardiovascular health (CVH) metrics and cardiovascular disease (CVD) management indicators and identified research needed to fill gaps in policy and support further policy development. METHODS AND RESULTS: The AHA policy research department first identified current AHA policies specific to each CVH metric and CVD management indicator and the evidence underlying each policy. Writing group members then reviewed each policy and the related metrics and indicators. The results of each review were summarized, and topic-specific priorities and overarching themes for future policy research were proposed. There was generally close alignment between current AHA policies and the 2020 CVH metrics and CVD management indicators; however, certain specific policies still lack a robust evidence base. For CVH metrics, the distinction between policies for adults (age ≥20 years) and children (<20 years) was often not considered, although policy approaches may differ importantly by age. Inclusion of all those <20 years of age as a single group also ignores important differences in policy needs for infants, children, adolescents, and young adults. For CVD management indicators, specific quantitative targets analogous to criteria for ideal, intermediate, and poor CVH are lacking but needed to assess progress toward the 2020 goal to reduce deaths from CVDs and stroke. New research in support of current policies needs to focus on the evaluation of their translation and implementation through expanded application of implementation science. Focused basic, clinical, and population research is required to expand and strengthen the evidence base for the development of new policies. Evaluation of the impact of targeted improvements in population health through strengthened surveillance of CVD and stroke events, determination of the cost-effectiveness of policy interventions, and measurement of the extent to which vulnerable populations are reached must be assessed for all policies. Additional attention should be paid to the social determinants of health outcomes. CONCLUSIONS: AHA's public policies are generally robust and well aligned with its 2020 CVH metrics and CVD indicators. Areas for further policy development to fill gaps, overarching research strategies, and topic-specific priority areas are proposed.

Socioeconomic inequality and peripheral artery disease prevalence in US adults.

BACKGROUND: Lower socioeconomic status is associated with cardiovascular disease. We sought to determine whether there is a higher prevalence of peripheral artery disease (PAD) in individuals with lower socioeconomic status. METHODS AND RESULTS: We analyzed data from the National Health and Nutrition Examination Survey 1999 to 2004. PAD was defined based on an ankle.brachial index .0.90. Measures of socioeconomic status included poverty.income ratio,a ratio of self-reported income relative to the poverty line, and attained education level. Of 6791 eligible participants,overall weighted prevalence of PAD was 5.8% (SE, 0.3). PAD prevalence was significantly higher in individuals with low income and lower education. Individuals in the lowest of the 6 poverty.income ratio categories had more than a2-fold increased odds of PAD compared with those in the highest poverty-income ratio category (odds ratio, 2.69; 95%confidence interval, 1.80.4.03; P<0.0001). This association remained significant even after multivariable adjustment(odds ratio, 1.64; 95% confidence interval, 1.04.2.6; P=0.034). Lower attained education level also associated with higher PAD prevalence (odds ratio, 2.8; 95% confidence interval, 1.96.4.0; P<0.0001) but was no longer significant after multivariable adjustment. CONCLUSIONS: Low income and lower attained education level are associated with PAD in US adults. These data suggest that individuals of lower socioeconomic status remain at high risk and highlight the need for education and advocacy efforts focused on these at-risk populations.