Association of abnormal p-wave parameters with brain MRI morphology: The atherosclerosis risk in communities neurocognitive study (ARIC-NCS).

BACKGROUND: Recent evidence indicates that abnormal P-wave parameters (PWPs)-ECG markers of atrial myopathy-are associated with incident dementia, independent of atrial fibrillation (AF) and clinical ischemic stroke. However, the mechanisms remain unclear and may include subclinical vascular brain injury. Hence, we evaluated the association of abnormal PWPs with brain MRI correlates of vascular brain injury in the Atherosclerosis Risk in Communities Neurocognitive Study (ARIC-NCS). METHODS: ARIC-NCS participants who underwent 3T brain MRI scans in 2011-2013 were included. PWPs were measured from standard 12-lead ECGs. Brain MRI outcomes included cortical infarcts, lacunar infarcts, cerebral microhemorrhages, brain volumes, and white matter disease (WMD) volume. We used weighted multivariable logistic and linear regression to evaluate the associations of abnormal PWPs with brain MRI outcomes. RESULTS: Among 1715 participants (mean age, 76.1 years; 61% women; 29% Black), 797 (46%) had ≥1 abnormal PWP. After multivariable adjustment, including adjusting for prevalent AF, abnormal P-wave terminal force in lead V1 (aPTFV1) and prolonged P-wave duration (PPWD) were associated with increased odds of both cortical (OR 1.41; 95% CI, 1.14 to 1.74 and OR 1.30; 95% CI, 1.04 to 1.63, respectively) and lacunar infarcts (OR 1.36; 95% CI, 1.15 to 1.63 and OR 1.37; 95% CI, 1.15 to 1.65, respectively). Advanced interatrial block (aIAB) was associated with higher odds of subcortical microhemorrhage (OR 2.04; 95% CI, 1.36 to 3.06). Other than a significant association between aPTFV1 with lower parietal lobe volume, there were no other significant associations with brain or WMD volume. CONCLUSION: In this exploratory analysis of a US community-based cohort, ECG surrogates of atrial myopathy are associated with a higher prevalence of brain infarcts and microhemorrhage, suggesting subclinical vascular brain injury as a possible mechanism underlying the association of atrial myopathy with dementia.

A community-based group randomized trial to increase aspirin use for primary prevention of cardiovascular disease: Study protocol and baseline results for the "Ask About Aspirin" initiative.

BACKGROUND: USPSTF evidence-based recommendations for the use of low-dose aspirin for primary prevention of cardiovascular disease were published in 2009. We describe a statewide campaign using innovative methods to educate the public and health communities about appropriate aspirin use. METHODS/DESIGN: The "Ask About Aspirin" initiative is designed to lower the number of first heart attacks and strokes in the State of Minnesota by promoting the appropriate use of low dose aspirin. A health system intervention combined with an aspirin awareness media campaign will be evaluated in a pragmatic group randomized controlled trial including 267 primary care clinics within 84 health systems over a four year period. Matched pairs of geographic territories will be randomized to intervention (12 territories) or control (12 territories). The primary outcome of appropriate aspirin use will be measured at the individual level, by community-based telephone surveys of 100 participants in each of the 24 geographically determined clusters. DISCUSSION: We briefly describe the rationale for the interventions being studied, as well as the major design choices. Rigorous research designs such as the one described here are necessary to determine whether evidence-based recommendations can be effectively disseminated in multiple health systems. TRIAL REGISTRATION: ClinicalTrials.gov: NCT02607917.

Promoting Aspirin Use for Cardiovascular Disease Prevention Among an Adult Internet-Using Population: A Pilot Study.

Cardiovascular disease prevention strategies include aspirin use as a preventive measure. The internet can be used to raise public awareness, promote healthy lifestyles, and improve disease management. This pilot study describes the feasibility of an educational website to recruit and follow adult internet users to examine whether they talked to their physician about aspirin and initiated aspirin use. As part of a statewide intervention promoting an aspirin regimen to prevent heart attacks and strokes in Minnesota, visitors to the website were encouraged to complete an aspirin candidacy tool. Between October, 2015 and February, 2016, men 45-79 and women 55-79 who identified as aspirin candidates were invited to participate in a 6-month study involving four, 5 min online surveys to examine physician discussions about aspirin, aspirin use, and mobile technology use. During the 5-month recruitment period, 234 adults enrolled in the study. Of the 174 who completed the baseline survey and at least one follow-up survey, 74 (43.5%) did not use aspirin at baseline. During follow-up, 12 (16.2%) talked to their doctor about aspirin and 31 (41.8%) initiated aspirin use. Internet, social media, and mobile technology use were high among this population. An educational website may have provided a cue to action for aspirin discussions with physicians and aspirin initiation. More research is needed to evaluate the utility of on-line tools to increase appropriate aspirin use among internet-using populations.

Low-dose aspirin for primary prevention of cardiovascular disease: Trends in use patterns among African American adults in Minnesota, 2015-2019.

Cardiovascular disease (CVD) disproportionately affects African Americans. Aspirin has long been recommended to reduce cardiovascular events. However, national guideline changes in 2016 limited the aspirin recommended population and several clinical trials questioning the utility of primary prevention aspirin were published in 2018. In light of the recent guidelines and study findings, we investigated primary prevention aspirin use among urban African American adults. Using three cross-sectional surveys, we collected data from self-identified African Americans with no CVD in 2015, 2017 and 2019, querying information on CVD risk factors, health behaviors and beliefs, and aspirin use. Poisson regression modeling was used to estimate age- and risk-factor adjusted aspirin prevalence, trends and associations. A total of 1491 African Americans adults, ages 45-79, were included in this analysis; 61% were women. There was no change in age- and risk factor-adjusted aspirin use over the 3 surveys for women (37%, 34% and 35% respectively) or men (27%, 25%, 30% respectively). However, fewer participants believed aspirin was helpful in 2019 compared to 2015-75% versus 84% (p < 0.001). Aspirin discussions with a health care practitioner were highly associated with aspirin use (adjusted RR 2.97, 95% CI 2.49-3.54) and aspirin use was 2.56 times higher (adjusted RR 95% CI 2.17-3.03) in respondents who agreed that people close to them thought they should take aspirin compared with those who disagreed or did not know. Despite major changes in national guidelines, overall primary prevention aspirin use did not significantly change in these African American samples from 2015 to 2019.

Life's Simple 7 cardiovascular health score and premature atrial contractions: The atherosclerosis risk in communities (ARIC) study.

BACKGROUND: Premature atrial contractions (PACs) are associated with increased risk of atrial fibrillation (AF) and ischemic stroke. Although lifestyle and risk factor modification reduces AF incidence, their relationship to PACs frequency is unclear. We assessed the association of Life's Simple 7 (LS7) and individual LS7 factors in midlife with PACs frequency in late life in the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: We followed 1924 participants from ARIC clinic Visit 3 (1993--95) to Visit 6 (2016-17) when a 2-week continuous heart rhythm monitor (Zio®XT Patch) was applied. LS7 factors were assessed at Visit 3 and a composite score was calculated. PACs frequency was categorized as minimal (<0.1%), occasional (≥0.1%-5%) and frequent (>5%). Logistic regression was used to evaluate the association of LS7 score and individual factors with PACs frequency. RESULTS: Each 1-point LS7 score increase was associated with lower odds of frequent PACs vs. no PACs (OR [95% CI]: 0.87 [0.78, 0.98]) and frequent PACs vs. occasional PACs (OR [95% CI]: 0.88 [0.79, 0.98]). Of the individual LS7 factors, compared with ideal physical activity, poor physical activity was associated with 81% higher odds of frequent PACs vs. no PACs. Compared with ideal BMI, poor BMI was associated with 41% higher odds of occasional PACs vs. no PACs. CONCLUSION: Lifestyle risk factors, particularly physical activity and BMI, are associated with higher odds of PACs frequency. More research is needed to determine whether modifying these risk factors in midlife would prevent frequent PACs, and thereby prevent AF and stroke in older age.

Aspirin Use and Misuse for the Primary Prevention of Cardiovascular Diseases.

INTRODUCTION: Daily aspirin use for primary cardiovascular disease prevention is common among adults. Numerous clinical trials observe reduced cardiovascular disease with regular low-dose aspirin. The U.S. Preventive Services Task Force in 2016 published guidelines for aspirin use, but controversy exists about the side effects, and overuse or underuse may be common despite the guidelines. Using the Task Force recommendations, this paper describes the prevalence of appropriate aspirin use and physician advice in a population sample. METHODS: A random sample of men and women (aged 50-69 years) living in the Upper Midwest in 2017-2018 were surveyed, collecting demographic data, health history, and aspirin use. Appropriate primary prevention with aspirin was defined as having ≥10% cardiovascular disease risk (hypertension, hyperlipidemia, diabetes, smoking) with daily or every other day aspirin use. Those with prevalent cardiovascular disease were labeled as secondary prevention. RESULTS: A total of 1,352 adults were surveyed (697 women, 655 men). The criteria for secondary prevention were fulfilled in 188 participants, and these were eliminated from the analysis. In the remaining group, aspirin was indicated in 32.9% (383 of 1,164). Among those, 46.0% (176 of 383) were appropriate users, and 54.0% (207 of 383) were nonusers despite indications. Overuse, where aspirin is not indicated, was common at 26.9% (210 of 781). Discussion with a physician, although reported in 29% of subjects, was associated with some improvement in the appropriate use but also with overuse and underuse. CONCLUSIONS: Aspirin use for primary cardiovascular disease prevention is common. However, many adults are medicating without indication (overuse) or are not using aspirin despite guidelines (underuse).

Aspirin Use and Awareness for Cardiovascular Disease Prevention Among Hispanics: Prevalence and Associations with Health Behavior Beliefs.

Cardiovascular disease (CVD) persists as the leading cause of death and disability in many Americans including Hispanics. Primary prevention for CVD may be achieved through regular aspirin use in high risk individuals. This study examined regular aspirin use and specific attitudes and social norms toward CVD and aspirin use within an urban Hispanic population in Minnesota. A sample of primary prevention Hispanics aged 45-79 years were surveyed about CVD history and risk factors, aspirin use, demographic characteristics, and health beliefs and social norms in relation to CVD and aspirin. Relative risk estimation using Poisson regression with robust error variance was used to examine associations with aspirin use. In this sample of 152 Hispanics (55% women), the mean age was 53 years, 70% had a regular healthcare provider, and 22% used aspirin. Aspirin discussions with a regular healthcare provider were strongly associated with aspirin use (adjusted risk ratio 3.02, 95% CI 1.20-7.60). There was a positive association between health beliefs and social norms that affirm preventive behaviors and aspirin use (adjusted linear risk ratio 1.23, 95% CI 1.04-1.45) while uncertainty about the role of aspirin for individual use and in the community was negatively associated with aspirin use (adjusted linear risk ratio 0.85, 95% CI 0.70-1.03). This growing population may benefit from health education about CVD risk and the role of aspirin in prevention.

Aspirin Use for Cardiovascular Disease Prevention in an African American Population: Prevalence and Associations with Health Behavior Beliefs.

Cardiovascular disease (CVD) is a leading cause of morbidity and mortality in the United States, disproportionately affecting African Americans. Aspirin is an effective, low cost option to reduce cardiovascular events. This study sought to describe the use of aspirin for CVD prevention in African Americans and evaluate associations with demographics, cardiovascular risk factors and health behaviors and beliefs. A total of 684 African Americans adults ages 45-79 years completed surveys and were included in this analysis. Proportions of aspirin use were stratified by primary and secondary prevention and by number of CVD risk factors in the primary prevention population. Logistic regression was used to evaluate associations with aspirin use. Secondary prevention aspirin use was 62%. Primary prevention aspirin use was 32% overall and increased to 54% in those with > 2 CVD risk factors. A history of diabetes [adjusted odds ratio (aOR) 3.42, 95% CI 2.18-5.35] and hypertension (aOR 2.25, 95% CI 1.39-3.65) were strongly associated with primary prevention aspirin use, but a conversation with a health care provider was even stronger (aOR 6.41, 95% CI 4.07-10.08). Participants who answered positively to statements about people similar to them taking aspirin or that close contacts think they should take aspirin, were much more likely to take aspirin (aOR 4.80; 95% CI 2.58-8.93 and aOR 7.45; 95% CI 4.70-11.79 respectively). These findings support a hypothesis that aspirin use may increase by encouraging conversations with health care providers and creating a supportive social environment for aspirin use. Further studies need to be done to test this hypothesis.

The Contribution of Tobacco Use to High Health Care Utilization and Medical Costs in Peripheral Artery Disease: A State-Based Cohort Analysis.

BACKGROUND: Tobacco use is an important preventable cause of peripheral artery disease (PAD) and a major determinant of adverse clinical outcomes. OBJECTIVES: This study hypothesized that tobacco use by PAD patients would be associated with higher health care utilization and associated costs. METHODS: We conducted a retrospective, cross-sectional study using 2011 claims data from the largest Minnesota health plan. The total cohort included individuals with 12 months of continuous enrollment and ≥ 1 PAD-related claim. Tobacco cessation pharmacotherapy billing codes were queried in a subgroup with pharmacy benefits. Outcomes were total costs, annual proportion of members hospitalized, and primary discharge diagnoses. RESULTS: A PAD cohort of 22,203 was identified, comprising 1,995 (9.0%) tobacco users. A subgroup of 9,027 with pharmacy benefits included 1,158 (12.8%) tobacco users. The total cohort experienced 22,220 admissions. The pharmacy benefits subgroup experienced 8,152 admissions. Within 1 year, nearly one-half the PAD tobacco users were hospitalized, 35% higher than nonusers in the total cohort (p < 0.001) and 30% higher in the subgroup (p < 0.001). In both cohorts, users were more frequently admitted for peripheral or visceral atherosclerosis (p < 0.001), acute myocardial infarction (p < 0.001), and coronary heart disease (p < 0.05). Observed costs in the total cohort were $64,041 for tobacco users versus $45,918 for nonusers. Costs for tobacco users also were consistently higher for professional and facility-based care, persisting after adjustment for age, sex, comorbidities, and insurance type. CONCLUSIONS: Tobacco use in PAD is associated with substantial increases in PAD-related hospitalizations, coronary heart disease and PAD procedures, and significantly greater costs. The results suggest that immediate provision of tobacco cessation programs may be especially cost effective.

Supervised exercise, stent revascularization, or medical therapy for claudication due to aortoiliac peripheral artery disease: the CLEVER study.

BACKGROUND: Treatment for claudication that is due to aortoiliac peripheral artery disease (PAD) often relies on stent revascularization (ST). However, supervised exercise (SE) is known to provide comparable short-term (6-month) improvements in functional status and quality of life. Longer-term outcomes are not known. OBJECTIVES: The goal of this study was to report the longer-term (18-month) efficacy of SE compared with ST and optimal medical care (OMC). METHODS: Of 111 patients with aortoiliac PAD randomly assigned to receive OMC, OMC plus SE, or OMC plus ST, 79 completed the 18-month clinical and treadmill follow-up assessment. SE consisted of 6 months of SE and an additional year of telephone-based exercise counseling. Primary clinical outcomes included objective treadmill-based walking performance and subjective quality of life. RESULTS: Peak walking time improved from baseline to 18 months for both SE (5.0 ± 5.4 min) and ST (3.2 ± 4.7 min) significantly more than for OMC (0.2 ± 2.1 min; p < 0.001 and p = 0.04, respectively). The difference between SE and ST was not significant (p = 0.16). Improvement in claudication onset time was greater for SE compared with OMC, but not for ST compared with OMC. Many disease-specific quality-of-life scales demonstrated durable improvements that were greater for ST compared with SE or OMC. CONCLUSIONS: Both SE and ST had better 18-month outcomes than OMC. SE and ST provided comparable durable improvement in functional status and in quality of life up to 18 months. The durability of claudication exercise interventions merits its consideration as a primary PAD claudication treatment.

Development of administrative data algorithms to identify patients with critical limb ischemia.

Administrative data have been used to identify patients with various diseases, yet no prior study has determined the utility of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM)-based codes to identify CLI patients. CLI cases (n=126), adjudicated by a vascular specialist, were carefully defined and enrolled in a hospital registry. Controls were frequency matched to cases on age, sex and admission date in a 2:1 ratio. ICD-9-CM codes for all patients were extracted. Algorithms were developed using frequency distributions of these codes, risk factors and procedures prevalent in CLI. The sensitivity for each algorithm was calculated and applied within the hospital system to identify CLI patients not included in the registry. Sensitivity ranged from 0.29 to 0.92. An algorithm based on diagnosis and procedure codes exhibited the best overall performance (sensitivity of 0.92). Each algorithm had differing CLI identification characteristics based on patient location. Administrative data can be used to identify CLI patients within a health system. The algorithms, developed from these data, can serve as a tool to facilitate clinical care, research, quality improvement, and population surveillance.

The impact of prolonged lower limb ischemia on amputation, mortality, and functional status: the FRIENDS registry.

BACKGROUND: Peripheral artery disease (PAD) is a major cause of cardiovascular ischemic events and amputation. Knowledge gaps exist in defining and measuring key factors that predict these events. The objective of this study was to assess whether duration of limb ischemia would serve as a major predictor of limb and patient survival. METHODS: The FReedom from Ischemic Events: New Dimensions for Survival (FRIENDS) registry enrolled consecutive patients with limb-threatening peripheral artery disease at a single tertiary care hospital. Demographic information, key clinical care time segments, functional status and use of revascularization, and pharmacotherapy data were collected at baseline, and vascular ischemic events, cardiovascular mortality, and all-cause mortality were recorded at 30 days and 1 year. RESULTS: A total of 200 patients with median (interquartile range) age of 76 years (65-84 years) were enrolled in the registry. Median duration of limb ischemia was 0.75 days for acute limb ischemia (ALI) and 61 days for chronic critical limb ischemia (CLI). Duration of limb ischemia of <12, 12 to 24, and >24 hours in patients with ALI was associated with much higher rates of first amputation (P = .0002) and worse amputation-free survival (P = .037). No such associations were observed in patients with CLI. CONCLUSIONS: For individuals with ischemic symptoms <14 days, prolonged limb ischemia is associated with higher 30-day and 1-year amputation, systemic ischemic event rates, and worse amputation-free survival. No such associations are evident for individuals with chronic CLI. These data imply that prompt diagnosis and revascularization might improve outcomes for patients with ALI.

A 16-month community-based intervention to increase aspirin use for primary prevention of cardiovascular disease.

INTRODUCTION: Cardiovascular diseases are the leading causes of disability and death in the United States. Primary prevention of these events may be achieved through aspirin use. The ability of a community-based intervention to increase aspirin use has not been evaluated. The objective of this study was to evaluate an educational intervention implemented to increase aspirin use for primary prevention of cardiovascular disease in a small city in Minnesota. METHODS: A community-based intervention was implemented during 16 months in a medium-sized community in Minnesota. Messages for aspirin use were disseminated to individuals, health care professionals, and the general population. Independent cross-sectional samples of residents (men aged 45-79, women aged 55-79) were surveyed by telephone to identify candidates for primary prevention aspirin use, examine their characteristics, and determine regular aspirin use at baseline and after the campaign at 4 months and 16 months. RESULTS: In primary prevention candidates, regular aspirin use rates increased from 36% at baseline to 54% at 4 months (odds ratio = 2.05; 95% confidence interval, 1.09-3.88); the increase was sustained at 52% at 16 months (odds ratio = 1.89; 95% confidence interval, 1.02-3.49). The difference in aspirin use rates at 4 months and 16 months was not significant (P = .77). CONCLUSION: Aspirin use rates for primary prevention remain low. A combined public health and primary care approach can increase and sustain primary prevention aspirin use in a community setting.

The FReedom from Ischemic Events-New Dimensions for Survival (FRIENDS) registry: design of a prospective cohort study of patients with advanced peripheral artery disease.

BACKGROUND: Advanced lower extremity peripheral artery disease (PAD), whether presenting as acute limb ischemia (ALI) or chronic critical limb ischemia (CLI), is associated with high rates of cardiovascular ischemic events, amputation, and death. Past research has focused on strategies of revascularization, but few data are available that prospectively evaluate the impact of key process of care factors (spanning pre-admission, acute hospitalization, and post-discharge) that might contribute to improving short and long-term health outcomes. METHODS/DESIGN: The FRIENDS registry is designed to prospectively evaluate a range of patient and health system care delivery factors that might serve as future targets for efforts to improve limb and systemic outcomes for patients with ALI or CLI. This hypothesis-driven registry was designed to evaluate the contributions of: (i) pre-hospital limb ischemia symptom duration, (ii) use of leg revascularization strategies, and (iii) use of risk-reduction pharmacotherapies, as pre-specified factors that may affect amputation-free survival. Sequential patients would be included at an index "vascular specialist-defined" ALI or CLI episode, and patients excluded only for non-vascular etiologies of limb threat. Data including baseline demographics, functional status, co-morbidities, pre-hospital time segments, and use of medical therapies; hospital-based use of revascularization strategies, time segments, and pharmacotherapies; and rates of systemic ischemic events (e.g., myocardial infarction, stroke, hospitalization, and death) and limb ischemic events (e.g., hospitalization for revascularization or amputation) will be recorded during a minimum of one year follow-up. DISCUSSION: The FRIENDS registry is designed to evaluate the potential impact of key factors that may contribute to adverse outcomes for patients with ALI or CLI. Definition of new "health system-based" therapeutic targets could then become the focus of future interventional clinical trials for individuals with advanced PAD.

Correlation of patient-reported symptom outcomes and treadmill test outcomes after treatment for aortoiliac claudication.

PURPOSE: To examine the relationship between objective treadmill test outcomes and subjective symptom outcomes among patients with claudication treated with stent revascularization (ST) compared with supervised exercise (SE). MATERIALS AND METHODS: Five scales of the Peripheral Artery Questionnaire and Walking Impairment Questionnaire were correlated with peak walking time and treadmill claudication onset time. RESULTS: The correlation between change in disease-specific quality of life (QOL) and change in peak walking time differed according to treatment group, with statistically significant correlations for all five scales for the ST group and weaker trends for the SE group, only one of which was statistically significant. In contrast, improvements in disease-specific QOL correlated well with increases in claudication onset time, with no significant interaction with treatment group for any of the five scales. CONCLUSIONS: Disease-specific QOL results at 6 months in the Claudication: Exercise Vs. Endoluminal Revascularization (CLEVER) study show that improved maximal treadmill walking in patients with claudication treated with SE correlated poorly with self-reported symptom relief. Conversely, patients treated with ST showed good correlation between improved maximal treadmill walking and self-reported symptom improvement. The correlation between claudication onset time and self-reported symptom relief was good across treatment groups. This finding indicates that traditional objective treadmill test outcomes may not correlate well with symptom relief in patients with claudication. Future studies should investigate these data and improve understanding of patient relevance of traditional objective treadmill-based treatment outcomes.

Supervised exercise versus primary stenting for claudication resulting from aortoiliac peripheral artery disease: six-month outcomes from the claudication: exercise versus endoluminal revascularization (CLEVER) study.

BACKGROUND: Claudication is a common and disabling symptom of peripheral artery disease that can be treated with medication, supervised exercise (SE), or stent revascularization (ST). METHODS AND RESULTS: We randomly assigned 111 patients with aortoiliac peripheral artery disease to receive 1 of 3 treatments: optimal medical care (OMC), OMC plus SE, or OMC plus ST. The primary end point was the change in peak walking time on a graded treadmill test at 6 months compared with baseline. Secondary end points included free-living step activity, quality of life with the Walking Impairment Questionnaire, Peripheral Artery Questionnaire, Medical Outcomes Study 12-Item Short Form, and cardiovascular risk factors. At the 6-month follow-up, change in peak walking time (the primary end point) was greatest for SE, intermediate for ST, and least with OMC (mean change versus baseline, 5.8±4.6, 3.7±4.9, and 1.2±2.6 minutes, respectively; P<0.001 for the comparison of SE versus OMC, P=0.02 for ST versus OMC, and P=0.04 for SE versus ST). Although disease-specific quality of life as assessed by the Walking Impairment Questionnaire and Peripheral Artery Questionnaire also improved with both SE and ST compared with OMC, for most scales, the extent of improvement was greater with ST than SE. Free-living step activity increased more with ST than with either SE or OMC alone (114±274 versus 73±139 versus -6±109 steps per hour), but these differences were not statistically significant. CONCLUSIONS: SE results in superior treadmill walking performance than ST, even for those with aortoiliac peripheral artery disease. The contrast between better walking performance for SE and better patient-reported quality of life for ST warrants further study. CLINICAL TRIAL REGISTRATION: URL: http://clinicaltrials.gov/ct/show/NCT00132743?order=1. Unique identifier: NCT00132743.

The incidence and health economic burden of ischemic amputation in Minnesota, 2005-2008.

INTRODUCTION: Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery disease (PAD), is associated with high rates of myocardial infarction, stroke, and amputation, and has a high health economic cost. The objective of this study was to estimate the incidence of lower limb amputation, the most serious consequence of CLI, and to create a surveillance methodology for the incidence of ischemic amputation in Minnesota. METHODS: We assessed the incidence of ischemic amputation using all inpatient hospital discharge claims in Minnesota from 2005 through 2008. We identified major and minor ischemic amputations via the International Classification of Diseases, 9th Revision, Clinical Modification (ICD-9-CM) procedure codes for lower limb amputation not due to trauma or cancer and assessed geographic and demographic differences in the incidence of ischemic amputation. RESULTS: The age-adjusted annual incidence of lower limb ischemic amputation in Minnesota during the 4-year period was 20.0 per 100,000 (95% confidence interval, 19.4-20.6). Amputations increased significantly with age, were more common in men and in people with diabetes, and were slightly more common in rural residents. The number of amputation-related hospitalizations was steady over 4 years. The median total charge for each amputation was $32,129, and cumulative inpatient hospitalization charges were $56.5 million in 2008. CONCLUSION: The incidence of ischemic amputation is high and results in major illness and health economic costs. These data represent the first population-based estimate of ischemic amputation at the state level and provide a national model for state-based surveillance.