Genetic and clinical determinants of abdominal aortic diameter: genome-wide association studies, exome array data and Mendelian randomization study.

Progressive dilation of the infrarenal aortic diameter is a consequence of the ageing process and is considered the main determinant of abdominal aortic aneurysm (AAA). We aimed to investigate the genetic and clinical determinants of abdominal aortic diameter (AAD). We conducted a meta-analysis of genome-wide association studies in 10 cohorts (n = 13 542) imputed to the 1000 Genome Project reference panel including 12 815 subjects in the discovery phase and 727 subjects [Partners Biobank cohort 1 (PBIO)] as replication. Maximum anterior-posterior diameter of the infrarenal aorta was used as AAD. We also included exome array data (n = 14 480) from seven epidemiologic studies. Single-variant and gene-based associations were done using SeqMeta package. A Mendelian randomization analysis was applied to investigate the causal effect of a number of clinical risk factors on AAD. In genome-wide association study (GWAS) on AAD, rs74448815 in the intronic region of LDLRAD4 reached genome-wide significance (beta = -0.02, SE = 0.004, P-value = 2.10 × 10-8). The association replicated in the PBIO1 cohort (P-value = 8.19 × 10-4). In exome-array single-variant analysis (P-value threshold = 9 × 10-7), the lowest P-value was found for rs239259 located in SLC22A20 (beta = 0.007, P-value = 1.2 × 10-5). In the gene-based analysis (P-value threshold = 1.85 × 10-6), PCSK5 showed an association with AAD (P-value = 8.03 × 10-7). Furthermore, in Mendelian randomization analyses, we found evidence for genetic association of pulse pressure (beta = -0.003, P-value = 0.02), triglycerides (beta = -0.16, P-value = 0.008) and height (beta = 0.03, P-value < 0.0001), known risk factors for AAA, consistent with a causal association with AAD. Our findings point to new biology as well as highlighting gene regions in mechanisms that have previously been implicated in the genetics of other vascular diseases.

Discordance of patient-reported outcome measures with objectively assessed walking decline in peripheral artery disease.

OBJECTIVE: Among people with peripheral artery disease (PAD), perceived change in walking difficulty over time, compared with people without PAD, is unclear. Among people reporting no change in walking difficulty over time, differences in objectively measured change in walking performance between people with and without PAD are unknown. METHODS: A total of 1289 participants were included. Eight hundred seventy-four participants with PAD (aged 71.1 ± 9.1 years) were identified from noninvasive vascular laboratories and 415 without PAD (aged 69.9 ± 7.6 years) were identified from people with normal vascular laboratory testing or general medical practices in Chicago. The Walking Impairment Questionnaire and 6-minute walk were completed at baseline and 1-year follow-up. The Walking Impairment Questionnaire assessed perceived difficulty walking due to symptoms in the calves or buttocks on a Likert scale (range, 0-4). Symptom change was determined by comparing difficulty reported at 1-year follow-up to difficulty reported at baseline. RESULTS: At 1-year follow-up, 31.9% of participants with and 20.6% of participants without PAD reported walking difficulty that was improved (P < .01), whereas 41.2% vs 55%, respectively, reported walking difficulty that was unchanged (P < .01). Among all reporting no change in walking difficulty, participants with PAD declined in 6-minute walk, whereas participants without PAD improved (-10 vs +15 meters; mean difference, -25; 95% confidence interval, -38 to -13; P < .01). CONCLUSIONS: Most people with PAD reported improvement or no change in walking difficulty from calf or buttock symptoms at one-year follow-up. Among all participants who perceived stable walking ability, those with PAD had significant greater declines in objectively measured walking performance, compared with people without PAD.

Association between Statin use and Incident Peripheral Artery Disease According to Race, Age, and Presence of Depression in the Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Peripheral artery disease (PAD) is associated with high morbidity and mortality and has been commonly described as a coronary heart disease equivalent. Statin medications are recommended for primary prevention of atherosclerotic cardiovascular disease (CVD) among other indications. Therefore, understanding the longitudinal relationship of incident PAD is necessary to inform future research on how to prevent the disease. Depression complicates CVD patients' ability to properly adhere to their medications, yet the effect of depression on the relationship between statin use and incident PAD is understudied. People with PAD have a higher incidence of depressive symptoms than people without PAD. Black American and Hispanic populations are disproportionately affected by both PAD and depression yet research on the modifying effect of either race or depression on the relationship between statin use and onset of PAD is minimal. While statin utilization is highest for ages 75-84 years, there is minimal evidence of favorable risk-benefit balance. Consequently, in this project, we examined the relationship between statin use and incident PAD and whether this relationship is modified by race/ethnicity, depressive symptoms, or age. METHODS: We used data on participants from the Multi-Ethnic Study of Atherosclerosis from visit 1 (2000) through study visit 6 (2020) who had three separate measurements of the ankle-brachial index (ABI) taken at visit 1, visit 3, and visit 5. Incident PAD was defined as 1) incident lower extremity amputation or revascularization or 2) ABI less than 0.90 coupled with ABI decrease greater than 0.15 over the follow-up period. Statin use was noted on the study visit prior to incident PAD diagnosis while depressive symptoms were measured at exam 1, visit 3, and visit 5. Propensity score matching was implemented to create balance between the participants in the two treatment groups, that is, statin-treated and statin-untreated groups, to reduce the problem of confounding by indication. Propensity scores were calculated using multivariate logistic regression model to estimate the probability of receiving statin treatment. We used Cox proportional hazards regression to investigate the relationship between time-dependent statin use as well as other risk factors with incident PAD, overall and stratified by 1) race, 2) depression status, and 3) age. RESULTS: A total of 4,210 participants were included in the final matched analytic cohort. There were 810 incident cases (19.3%) of PAD that occurred over an average (mean) of 11.3 years (SD = 5.7) of follow-up time. In the statin-treated group, and with an average follow-up time of 12.5 years (SD = 5.6), there were 281 cases (13.4%) of incident PAD with the average follow-up time of 10.1 years (SD = 5.5), whereas in the statin-untreated group, there were 531 cases (25.2%) (P < 0.001). Results demonstrate a lower risk of PAD event in the statin-treated group compared to the untreated group (hazard ratio [HR] = 0.45, 95% confidence interval [CI]: 0.33-0.62) over the span of 18.5 years. The interactions between 1) depression and 2) race with statin use for incident PAD were not significant. However, other risk factors which were significant included Black American race that had approximately 30% lower hazard of PAD compared to non-Hispanic White (HR = 0.70, 95% CI: 0.58-0.84); age-stratified models were also fitted, and stain use was still a significant treatment factor for ages 45-54 (HR = 0.45, 95% CI: 0.33-0.63), 55-64 (HR = 0.61, 95% CI: 0.46-0.79), and 65-74 years (HR = 0.61, 95% CI: 0.48-0.78) but not for ages 75-84 years. CONCLUSIONS: Statin use was associated with a decreased risk of incident PAD for those under the age of 75 years. Neither race nor depression significantly modified the relationship between statin use and incident PAD; however, the risk of incident PAD was lower among Black Americans. These findings highlight that the benefit of statin may wane for those over the age of 75 years. Findings also suggest that statin use may not be compromised in those living with depression.

Barriers to participation in supervised exercise therapy reported by people with peripheral artery disease.

OBJECTIVE: This study identified barriers to participation in supervised exercise therapy covered by the Centers for Medicare and Medicaid Services (CMS), reported by people with lower extremity peripheral artery disease (PAD). METHODS: People with PAD participating in research studies of walking impairment due to PAD in the Chicagoland area were asked to complete a questionnaire between March 15, 2019, and July 12, 2022, assessing their experience and attitudes about supervised exercise therapy. Participants were identified using mailed postcards to people aged 50 and older in Chicagoland, from medical centers in Chicago, and using bus and train advertisements. The questionnaire was developed based on focus group feedback from people with PAD. RESULTS: Of 516 participants with PAD approached, 489 (94.8%) completed the questionnaire (mean age: 71.0 years [standard deviation: 8.7], mean ankle-brachial index: 0.71 [standard deviation: 0.25]; 204 [41.7%] women and 261 [53.4%] Black). Of the 489 participants, 416 (85.1%) reported that their physician had never prescribed or recommended supervised exercise therapy. Overall, 357 (73.2%) reported willingness to travel three times weekly to the medical center for supervised exercise participation. However, of these, 214 (59.9%) reported that they were unwilling or unable to pay the $11 per exercise session copay required for supervised exercise covered by CMS. Of 51 people with PAD who reported prior participation in supervised exercise, only 5 (9.8%) completed the 12 weeks of supervised exercise therapy covered by CMS and 29 (56.9%) completed 6 or fewer weeks. Of 131 (26.8%) unwilling to travel three times weekly to a center for supervised exercise, the most common reasons for unwillingness to participate were "too time-consuming" (55.0%), "too inconvenient" (45.8%), and "lack of interest in treadmill exercise" (28.2%). CONCLUSIONS: Approximately 2 to 4 years after CMS began covering supervised exercise for PAD, most people with PAD in this study from a large urban area had not participated in supervised exercise therapy. Of those who participated, most completed fewer than half of the sessions covered by CMS. The required CMS copayment was a common barrier to supervised exercise participation by people with PAD.

Lower Extremity Peripheral Artery Disease: Contemporary Epidemiology, Management Gaps, and Future Directions: A Scientific Statement From the American Heart Association.

Lower extremity peripheral artery disease (PAD) affects >230 million adults worldwide and is associated with increased risk of various adverse clinical outcomes (other cardiovascular diseases such as coronary heart disease and stroke and leg outcomes such as amputation). Despite its prevalence and clinical importance, PAD has been historically underappreciated by health care professionals and patients. This underappreciation seems multifactorial (eg, limited availability of the first-line diagnostic test, the ankle-brachial index, in clinics; incorrect perceptions that a leg vascular disease is not fatal and that the diagnosis of PAD would not necessarily change clinical practice). In the past several years, a body of evidence has indicated that these perceptions are incorrect. Several studies have consistently demonstrated that many patients with PAD are not receiving evidence-based therapies. Thus, this scientific statement provides an update for health care professionals regarding contemporary epidemiology (eg, prevalence, temporal trends, risk factors, and complications) of PAD, the present status of diagnosis (physiological tests and imaging modalities), and the major gaps in the management of PAD (eg, medications, exercise therapy, and revascularization). The statement also lists key gaps in research, clinical practice, and implementation related to PAD. Orchestrated efforts among different parties (eg, health care providers, researchers, expert organizations, and health care organizations) will be needed to increase the awareness and understanding of PAD and improve the diagnostic approaches, management, and prognosis of PAD.

Evaluation of the Value of Waist Circumference and Metabolomics in the Estimation of Visceral Adipose Tissue.

Visceral adipose tissue (VAT) is a strong prognostic factor for cardiovascular disease and a potential target for cardiovascular risk stratification. Because VAT is difficult to measure in clinical practice, we estimated prediction models with predictors routinely measured in general practice and VAT as outcome using ridge regression in 2,501 middle-aged participants from the Netherlands Epidemiology of Obesity study, 2008-2012. Adding waist circumference and other anthropometric measurements on top of the routinely measured variables improved the optimism-adjusted R2 from 0.50 to 0.58 with a decrease in the root-mean-square error (RMSE) from 45.6 to 41.5 cm2 and with overall good calibration. Further addition of predominantly lipoprotein-related metabolites from the Nightingale platform did not improve the optimism-corrected R2 and RMSE. The models were externally validated in 370 participants from the Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS, 2006-2009) and 1,901 participants from the Multi-Ethnic Study of Atherosclerosis (MESA, 2000-2007). Performance was comparable to the development setting in PIVUS (R2 = 0.63, RMSE = 42.4 cm2, calibration slope = 0.94) but lower in MESA (R2 = 0.44, RMSE = 60.7 cm2, calibration slope = 0.75). Our findings indicate that the estimation of VAT with routine clinical measurements can be substantially improved by incorporating waist circumference but not by metabolite measurements.

Cocoa to Improve Walking Performance in Older People With Peripheral Artery Disease: The COCOA-PAD Pilot Randomized Clinical Trial.

RATIONALE: Cocoa and its major flavanol component, epicatechin, have therapeutic properties that may improve limb perfusion and increase calf muscle mitochondrial activity in people with lower extremity peripheral artery disease (PAD). OBJECTIVE: In a phase II randomized clinical trial, to assess whether 6 months of cocoa improved walking performance in people with PAD, compared with placebo. METHODS AND RESULTS: Six-month double-blind, randomized clinical trial in which participants with PAD were randomized to either cocoa beverage versus placebo beverage. The cocoa beverage contained 15 g of cocoa and 75 mg of epicatechin daily. The identical appearing placebo contained neither cocoa nor epicatechin. The 2 primary outcomes were 6-month change in 6-minute walk distance measured 2.5 hours after a study beverage at 6-month follow-up and 24 hours after a study beverage at 6-month follow-up, respectively. A 1-sided P<0.10 was considered statistically significant. Of 44 PAD participants randomized (mean age, 72.3 years [±7.1]; mean ankle brachial index, 0.66 [±0.15]), 40 (91%) completed follow-up. Adjusting for smoking, race, and body mass index, cocoa improved 6-minute walk distance at 6-month follow-up by 42.6 m ([90% CI, +22.2 to +∞] P=0.005) at 2.5 hours after a final study beverage and by 18.0 m ([90% CI, -1.7 to +∞] P=0.12) at 24 hours after a study beverage, compared with placebo. In calf muscle biopsies, cocoa improved mitochondrial COX (cytochrome c oxidase) activity (P=0.013), increased capillary density (P=0.014), improved calf muscle perfusion (P=0.098), and reduced central nuclei (P=0.033), compared with placebo. CONCLUSIONS: These preliminary results suggest a therapeutic effect of cocoa on walking performance in people with PAD. Further study is needed to definitively determine whether cocoa significantly improves walking performance in people with PAD. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02876887. Visual Overview: An online visual overview is available for this article.

Coronary calcium density in relation to coronary heart disease and cardiovascular disease in adults with diabetes or metabolic syndrome: the Multi-ethnic Study of Atherosclerosis (MESA).

BACKGROUND: Coronary artery calcium (CAC) density is inversely associated with coronary heart disease (CHD) and cardiovascular disease (CVD) risk. We examined this relation in those with diabetes mellitus (DM) or metabolic syndrome (MetS). METHODS: We studied 3,818 participants with non-zero CAC scores from the Multiethnic Study of Atherosclerosis and classified them as DM, MetS (without DM) or neither DM/MetS. Risk factor-adjusted CAC density was calculated and examined in relation to incident CHD and CVD events over a median follow-up of 15 years among these three disease groups. RESULTS: Adjusted CAC density was 2.54, 2.61 and 2.69 among those with DM, MetS or neither DM/MetS. Hazard ratios (HRs) for CHD per 1 SD increase of CAC density was 0.91 (95% CI: 0.72-1.16), 0.70 (95% CI: 0.56-0.87) and 0.79 (95% CI: 0.66-0.95) for those with DM, MetS or neither DM/MetS groups and were 0.77 (95% CI: 0.64-0.94), 0.83 (95% CI: 0.70-0.99) and 0.82 (95% CI: 0.71-0.95) for CVD, respectively. Adjustment for CAC density increased the HRs of CAC volume for CHD/CVD events. Compared to prediction models with or without single CAC measures, c-statistics of models with CAC volume and density were the highest ranging 0.67-0.72. CONCLUSION: CAC density is lower among patients with DM or MetS than those with neither DM/MetS and is inversely associated with future CHD/CVD risk among them. Including CAC density in risk assessment among those with MetS may improve prediction of CHD and CVD.

Effect of Telmisartan on Walking Performance in Patients With Lower Extremity Peripheral Artery Disease: The TELEX Randomized Clinical Trial.

Importance: Patients with lower extremity peripheral artery disease (PAD) have reduced lower extremity perfusion, impaired lower extremity skeletal muscle function, and poor walking performance. Telmisartan (an angiotensin receptor blocker) has properties that reverse these abnormalities. Objective: To determine whether telmisartan improves 6-minute walk distance, compared with placebo, in patients with lower extremity PAD at 6-month follow-up. Design, Setting, and Participants: Double-blind, randomized clinical trial conducted at 2 US sites and involving 114 participants. Enrollment occurred between December 28, 2015, and November 9, 2021. Final follow-up occurred on May 6, 2022. Interventions: The trial randomized patients using a 2 × 2 factorial design to compare the effects of telmisartan plus supervised exercise vs telmisartan alone and supervised exercise alone and to compare telmisartan alone vs placebo. Participants with PAD were randomized to 1 of 4 groups: telmisartan plus exercise (n = 30), telmisartan plus attention control (n = 29), placebo plus exercise (n = 28), or placebo plus attention control (n = 27) for 6 months. The originally planned sample size was 240 participants. Due to slower than anticipated enrollment, the primary comparison was changed to the 2 combined telmisartan groups vs the 2 combined placebo groups and the target sample size was changed to 112 participants. Main Outcomes and Measures: The primary outcome was the 6-month change in 6-minute walk distance (minimum clinically important difference, 8-20 m). The secondary outcomes were maximal treadmill walking distance; Walking Impairment Questionnaire scores for distance, speed, and stair climbing; and the 36-Item Short-Form Health Survey physical functioning score. The results were adjusted for study site, baseline 6-minute walk distance, randomization to exercise vs attention control, sex, and history of heart failure at baseline. Results: Of the 114 randomized patients (mean age, 67.3 [SD, 9.9] years; 46 were women [40.4%]; and 81 were Black individuals [71.1%]), 105 (92%) completed 6-month follow-up. At 6-month follow-up, telmisartan did not significantly improve 6-minute walk distance (from a mean of 341.6 m to 343.0 m; within-group change: 1.32 m) compared with placebo (from a mean of 352.3 m to 364.8 m; within-group change: 12.5 m) and the adjusted between-group difference was -16.8 m (95% CI, -35.9 m to 2.2 m; P = .08). Compared with placebo, telmisartan did not significantly improve any of the 5 secondary outcomes. The most common serious adverse event was hospitalization for PAD (ie, lower extremity revascularization, amputation, or gangrene). Three participants (5.1%) in the telmisartan group and 2 participants (3.6%) in the placebo group were hospitalized for PAD. Conclusions and Relevance: Among patients with PAD, telmisartan did not improve 6-minute walk distance at 6-month follow-up compared with placebo. These results do not support telmisartan for improving walking performance in patients with PAD. Trial Registration: ClinicalTrials.gov Identifier: NCT02593110.

Global, Regional, and Country-Specific Lifetime Risks of Stroke, 1990 and 2016.

BACKGROUND: The lifetime risk of stroke has been calculated in a limited number of selected populations. We sought to estimate the lifetime risk of stroke at the regional, country, and global level using data from a comprehensive study of the prevalence of major diseases. METHODS: We used the Global Burden of Disease (GBD) Study 2016 estimates of stroke incidence and the competing risks of death from any cause other than stroke to calculate the cumulative lifetime risks of first stroke, ischemic stroke, or hemorrhagic stroke among adults 25 years of age or older. Estimates of the lifetime risks in the years 1990 and 2016 were compared. Countries were categorized into quintiles of the sociodemographic index (SDI) used in the GBD Study, and the risks were compared across quintiles. Comparisons were made with the use of point estimates and uncertainty intervals representing the 2.5th and 97.5th percentiles around the estimate. RESULTS: The estimated global lifetime risk of stroke from the age of 25 years onward was 24.9% (95% uncertainty interval, 23.5 to 26.2); the risk among men was 24.7% (95% uncertainty interval, 23.3 to 26.0), and the risk among women was 25.1% (95% uncertainty interval, 23.7 to 26.5). The risk of ischemic stroke was 18.3%, and the risk of hemorrhagic stroke was 8.2%. In high-SDI, high-middle-SDI, and low-SDI countries, the estimated lifetime risk of stroke was 23.5%, 31.1% (highest risk), and 13.2% (lowest risk), respectively; the 95% uncertainty intervals did not overlap between these categories. The highest estimated lifetime risks of stroke according to GBD region were in East Asia (38.8%), Central Europe (31.7%), and Eastern Europe (31.6%), and the lowest risk was in eastern sub-Saharan Africa (11.8%). The mean global lifetime risk of stroke increased from 22.8% in 1990 to 24.9% in 2016, a relative increase of 8.9% (95% uncertainty interval, 6.2 to 11.5); the competing risk of death from any cause other than stroke was considered in this calculation. CONCLUSIONS: In 2016, the global lifetime risk of stroke from the age of 25 years onward was approximately 25% among both men and women. There was geographic variation in the lifetime risk of stroke, with the highest risks in East Asia, Central Europe, and Eastern Europe. (Funded by the Bill and Melinda Gates Foundation.).

Clinical characteristics and response to supervised exercise therapy of people with lower extremity peripheral artery disease.

BACKGROUND: Among people with lower extremity peripheral artery disease (PAD), little is known about variation in response to supervised exercise therapy (SET). Clinical characteristics associated with greater responsiveness to SET have not been identified. METHODS: Data from participants with PAD in two randomized clinical trials comparing SET vs nonexercising control were combined. The exercise intervention consisted of three times weekly supervised treadmill exercise. The control groups received lectures on health-related topics. RESULTS: Of 309 unique participants randomized (mean age, 67.9 years [standard deviation, 9.3 years]; 132 [42.7%] women; 185 [59.9%] black), 285 (92%) completed 6-month follow-up. Compared with control, those randomized to SET improved 6-minute walk distance by 35.6 meters (95% confidence interval, 21.4-49.8; P < .001). In the 95 (62.1%) participants who attended at least 70% of SET sessions, change in 6-minute walk distance varied from -149.4 to +356.0 meters. Thirty-four (35.8%) had no 6-minute walk distance improvement. Among all participants, age, sex, race, body mass index, prior lower extremity revascularization, and other clinical characteristics did not affect the degree of improvement in 6-minute walk distance after SET relative to the control group. Participants with 6-minute walk distance less than the median of 334 meters at baseline had greater percentage improvement in 6-minute walk distance compared with those with baseline 6-minute walk distance above the median (+20.5% vs +5.3%; P for interaction = .0107). CONCLUSIONS: Among people with PAD, substantial variability exists in walking improvement after SET. Shorter 6-minute walk distance at baseline was associated with greater improvement after SET, but other clinical characteristics, including age, sex, prior lower extremity revascularization, and disease severity, did not affect responsiveness to exercise therapy.

Meaningful change in 6-minute walk in people with peripheral artery disease.

OBJECTIVE: The 6-minute walk test is a common outcome measure in clinical trials of people with lower extremity peripheral artery disease (PAD). However, what constitutes a meaningful change in the 6-minute walk distance has not been well defined for people with PAD. The present study related the change in the 6-minute walk distance to the degree of participant-reported improvement or decline in the 6-minute walk distance to define a meaningful change in the 6-minute walk distance for those with PAD. METHODS: Participants with PAD from three observational longitudinal studies completed the walking impairment questionnaire (WIQ) distance score and 6-minute walk at baseline and 1 year later. The WIQ distance score measures participants' perceived difficulty walking seven different distances without stopping (ranging from walking around the home to walking 5 blocks) on a 0 to 4 Likert scale, with 0 representing an inability to walk the distance and 4 representing no difficulty. The mean changes in the 6-minute walk distance corresponding to the participants' report of no change, 1-unit change, or 2-unit change, respectively, in the Likert scale score between the baseline and 1-year follow-up measures were calculated for each WIQ distance. RESULTS: A total of 777 participants with PAD (mean age, 71.2 ± 8.8 years; mean baseline 6-minute walk distance, 350.1 ± 118.1 meters) completed 5439 questions about their difficulty walking each WIQ distance at baseline and follow-up. Participants with PAD who reported no change in their difficulty in walking each WIQ distance between baseline and follow-up had a decline of 7.2 meters (95% confidence interval [CI], -11.6 to -2.8 meters) in the 6-minute walk test. Relative to those reporting no change in difficulty walking, the participants reporting 1- and 2-point improvements in walking ability showed 6-minute walk distance improvements of 7.8 meters (95% CI, -0.3 to 15.9 meters) and 20.1 meters (95% CI, 1.1-39.2 meters), respectively. Relative to those reporting no change in walking difficulty, those reporting 1- and 2-point declines in perceived walking difficulty showed declines of -11.2 meters (95% CI, -19.0 to -3.4 meters) and -23.8 meters (95% CI, -37.4 to -10.3 meters) in the 6-minute walk distance. CONCLUSIONS: Among people with PAD, ∼8- and ∼20-meter improvements in the 6-minute walk distance represent small and large improvements in walking ability, respectively. People with PAD who reported no change in their ability to walk distances over 1 year simultaneously declined by a mean of 7 meters in the 6-minute walk test. These findings will be useful for interpreting the results from randomized trials of interventions to improve the walking performance of people with PAD.

Sustained physical activity in peripheral artery disease: Associations with disease severity, functional performance, health-related quality of life, and subsequent serious adverse events in the LITE randomized clinical trial.

This study investigated cross-sectional associations of peripheral artery disease (PAD) severity (defined by the ankle-brachial index (ABI)) and amounts of daily sustained physical activity (PA) (defined as > 100 activity counts per minute lasting 5 consecutive minutes or more). This study also investigated associations of amounts of daily sustained PA with 6-minute walk (6MW) distance and the Short Form-36 physical functioning domain (SF-36 PF) score in cross-sectional analyses and with serious adverse events (SAEs) in longitudinal analyses of people with PAD. PA was measured continuously for 10 days using a tri-axial accelerometer at baseline in 277 participants with PAD randomized to the LITE clinical trial. In regression analyses, each 0.15 lower ABI value was associated with a 5.67% decrease in the number of daily bouts of sustained PA (95% CI: 3.85-6.54; p < 0.001). Every additional bout of sustained PA per day was associated with a 4.56-meter greater 6MW distance (95% CI: 2.67-6.46; p < 0.0001), and a 0.81-point improvement in SF-36 PF score (95% CI: 0.34-1.28; p < 0.001). Participants with values of daily bouts of sustained PA below the median had higher rates of SAEs during follow-up, compared to participants above the median (41% vs 24%; p = 0.002). In conclusion, among participants with PAD, lower ABI values were associated with fewer bouts of daily sustained PA. A greater number of bouts of daily sustained PA were associated with better 6MW performance and SF-36 PF score, and, in longitudinal analyses, lower rates of SAEs. Clinicaltrials.gov ID: NCT02538900.

Effect of Low-Intensity vs High-Intensity Home-Based Walking Exercise on Walk Distance in Patients With Peripheral Artery Disease: The LITE Randomized Clinical Trial.

Importance: Supervised high-intensity walking exercise that induces ischemic leg symptoms is the first-line therapy for people with lower-extremity peripheral artery disease (PAD), but adherence is poor. Objective: To determine whether low-intensity home-based walking exercise at a comfortable pace significantly improves walking ability in people with PAD vs high-intensity home-based walking exercise that induces ischemic leg symptoms and vs a nonexercise control. Design, Setting, and Participants: Multicenter randomized clinical trial conducted at 4 US centers and including 305 participants. Enrollment occurred between September 25, 2015, and December 11, 2019; final follow-up was October 7, 2020. Interventions: Participants with PAD were randomized to low-intensity walking exercise (n = 116), high-intensity walking exercise (n = 124), or nonexercise control (n = 65) for 12 months. Both exercise groups were asked to walk for exercise in an unsupervised setting 5 times per week for up to 50 minutes per session wearing an accelerometer to document exercise intensity and time. The low-intensity group walked at a pace without ischemic leg symptoms. The high-intensity group walked at a pace eliciting moderate to severe ischemic leg symptoms. Accelerometer data were viewable to a coach who telephoned participants weekly for 12 months and helped them adhere to their prescribed exercise. The nonexercise control group received weekly educational telephone calls for 12 months. Main Outcomes and Measures: The primary outcome was mean change in 6-minute walk distance at 12 months (minimum clinically important difference, 8-20 m). Results: Among 305 randomized patients (mean age, 69.3 [SD, 9.5] years, 146 [47.9%] women, 181 [59.3%] Black patients), 250 (82%) completed 12-month follow-up. The 6-minute walk distance changed from 332.1 m at baseline to 327.5 m at 12-month follow-up in the low-intensity exercise group (within-group mean change, -6.4 m [95% CI, -21.5 to 8.8 m]; P = .34) and from 338.1 m to 371.2 m in the high-intensity exercise group (within-group mean change, 34.5 m [95% CI, 20.1 to 48.9 m]; P < .001) and the mean change for the between-group comparison was -40.9 m (97.5% CI, -61.7 to -20.0 m; P < .001). The 6-minute walk distance changed from 328.1 m at baseline to 317.5 m at 12-month follow-up in the nonexercise control group (within-group mean change, -15.1 m [95% CI, -35.8 to 5.7 m]; P = .10), which was not significantly different from the change in the low-intensity exercise group (between-group mean change, 8.7 m [97.5% CI, -17.0 to 34.4 m]; P = .44). Of 184 serious adverse events, the event rate per participant was 0.64 in the low-intensity group, 0.65 in the high-intensity group, and 0.46 in the nonexercise control group. One serious adverse event in each exercise group was related to study participation. Conclusions and Relevance: Among patients with PAD, low-intensity home-based exercise was significantly less effective than high-intensity home-based exercise and was not significantly different from the nonexercise control for improving 6-minute walk distance. These results do not support the use of low-intensity home-based walking exercise for improving objectively measured walking performance in patients with PAD. Trial Registration: ClinicalTrials.gov Identifier: NCT02538900.

Burden of Peripheral Artery Disease on Mortality and Incident Cardiovascular Events.

Using data from the Multi-Ethnic Study of Atherosclerosis (United States, 2000-2015), 6,527 racially/ethnically diverse adults (mean age, 62 (standard deviation, 10) years) free of known cardiovascular (CVD) had ankle brachial index (ABI) assessment of their bilateral dorsalis pedis/posterior tibial arteries (4 vessels total) and were followed for total mortality and incident CVD events/mortality. Individuals were classified into categories of 0-, 1-, 2-, 3- or 4-vessel peripheral artery disease (PAD) (ABI of ≤0.9). There were 1,202 deaths (18%), 656 incident CVD events (10%), and 282 CVD deaths (4.3%). Of the 6,527 individuals, 5,711 (87.5%) had 0-, 460 (7.0%) had 1-, 218 (3.3%) had 2-, 69 (1.1%) had 3-, and 69 (1.1%) had 4-vessel PAD, respectively. In multivariable Cox models, higher number of vessels with PAD was associated with higher risk of mortality (P for trend <0.001), CVD events (P for trend = 0.002), and CVD mortality (P for trend = 0.001). Compared with individuals who had 0-vessel disease, hazard ratios for mortality were 1.29 (95% confidence interval (CI): 1.06, 1.59) for 1-, 1.45 (95% CI: 1.14, 1.86) for 2-, 1.58 (95% CI: 1.13, 2.21) for 3-, and 2.15 (95% CI: 1.58, 2.94) for 4-vessel disease. A similar pattern was seen for CVD events/mortality. These results suggest the importance of accounting for ABI values of all 4 leg arteries in clinical practice and research.

Sedentary time and peripheral artery disease: The Hispanic Community Health Study/Study of Latinos.

BACKGROUND: Experimental evidence suggests that sedentary time (ST) may contribute to cardiovascular disease by eliciting detrimental hemodynamic changes in the lower limbs. However, little is known about objectively measured ST and lower extremity peripheral artery disease (PAD). METHODS: We included 7,609 Hispanic/Latinos (ages 45-74) from the Hispanic Community Health Study/Study of Latinos. PAD was measured using the ankle brachial index (≤0.9). ST was measured using accelerometry. We used multivariable logistic regression to assess associations of quartiles of ST and PAD, and then used the same logistic models with restricted cubic splines to investigate continuous nonlinear associations of ST and PAD. Models were sequentially adjusted for traditional PAD risk factors, leg pain, and moderate- to vigorous-intensity physical activity (MVPA). RESULTS: Median ST was 12.2 h/d, and 5.4% of individuals had PAD. In fully adjusted restricted cubic splines models accounting for traditional PAD risk factors, leg pain, and MVPA, ST had a significant overall (P = .048) and nonlinear (P = .024) association with PAD. A threshold effect was seen such that time spent above median ST was associated with higher odds of PAD. That is, compared to median ST, 1, 2, and 3 hours above median ST were associated with a PAD odds ratio of 1.16 (95% CI = 1.02-1.31), 1.44 (1.06-1.94), and 1.80 (1.11-2.90), respectively. CONCLUSIONS: Among Hispanic/Latino adults, ST was associated with higher odds of PAD, independent of leg pain, MVPA, and traditional PAD risk factors. Notably, we observed a threshold effect such that these associations were only observed at the highest levels of ST.

Clinical Characteristics and Outcomes of Patients With Heart Failure and Methamphetamine Abuse.

BACKGROUND: Despite a global epidemic of methamphetamine abuse, methamphetamine-associated heart failure (MethHF) remains poorly understood. We sought to evaluate characteristics and outcomes for patients with MethHF. METHODS: We reviewed the electronic health records of the University of California, San Diego, from 2005 to 2016. We compared characteristics and outcomes between 896 patients with MethHF and 20,576 patients with heart failure (HF) identified using diagnosis codes, urine toxicology, and natriuretic peptides. RESULTS: Compared with HF, patients with MethHF were younger (50±10 vs 67±16 years), predominantly male (72% vs 54%), and had more psychiatric and substance use comorbidities, including mood/anxiety disorders (29% vs 16%) and opioid use (44% vs 7%). MethHF had a higher 5-year HF readmission rate (64±4% vs 45±1%; hazard ratio [HR] 1.53, P < .001) and a lower 10-year total mortality rate (25±3% vs 28±1%; HR 0.85, P = .09). Predictors of poor outcomes included mood/anxiety disorders (HF readmission HR 1.41, P = .04) and opioid abuse (mortality HR 1.52, P = .04). CONCLUSIONS: Patients with MethHF are frequently encumbered by psychiatric and substance abuse comorbidities, and carry a substantial risk of HF readmission and mortality. Comprehensive efforts are needed to stem this emerging epidemic.

The association between liver fat and systemic calcified atherosclerosis.

BACKGROUND: The association of nonalcoholic fatty liver disease (NAFLD) with systemic calcified atherosclerosis, other than the coronary arteries, has not been clearly elucidated. We investigated the association between NAFLD and calcification in eight different vascular beds. METHODS: In a community-based cohort with computed tomography scans for carotid artery, coronary artery, thoracic aorta, abdominal aorta, iliac artery, renal artery, celiac trunk, and superior mesenteric artery, the association between NAFLD and arterial calcification was evaluated with adjustment for age, sex, hypertension, dyslipidemia, diabetes, obesity, current smoking status, and family history of heart disease in the first-degree relatives. RESULTS: In age- and sex-adjusted models, NAFLD was significantly associated with calcification in the coronary artery, carotid artery, thoracic aorta, celiac trunk, and superior mesenteric artery vascular beds (P < .05). However, adjustment for the traditional chronic venous disease risk factors attenuated the associations, except in the case of the thoracic aorta (odds ratio [OR], 1.38; 95% confidence interval [CI], 1.09-1.78) and celiac trunk (OR, 2.05; 95% CI, 1.16-3.65). In addition, NAFLD was independently associated with multiarterial calcification (four or more [OR, 1.33; 95% CI, 1.01-1.74], five or more [OR, 1.46; 95% CI, 1.09-1.97], and six or more [OR, 1.58; 95% CI, 1.09-2.30] of eight evaluated arterial segments). CONCLUSIONS: The association between NAFLD and arterial calcification is mainly mediated by conventional risk factors. The independent association between NAFLD and calcification in the thoracic aorta and celiac trunk as well as in a larger number of vascular beds needs confirmation in future prospective studies in diverse populations.

Comparing 6-minute walk versus treadmill walking distance as outcomes in randomized trials of peripheral artery disease.

BACKGROUND: Randomized trials of people with peripheral artery disease (PAD) and intermittent claudication have traditionally used maximal treadmill walking distance as the primary outcome, but the 6-minute walk test is increasingly used as a primary outcome in randomized trials of PAD. This study compared relative changes in maximal treadmill walking distance versus 6-minute walk distance in response to a therapeutic intervention or control in randomized trials of participants with PAD. METHODS: Data from four randomized trials of therapeutic interventions in participants with PAD that measured both 6-minute walk and treadmill walking performance at baseline and the 6-month follow-up were combined. Two trials studied supervised treadmill exercise, one studied home-based walking exercise, and one studied resveratrol. RESULTS: Of 467 participants (mean age, 69.8; standard deviation, 9.7), the mean ankle-brachial index was 0.66 (standard deviation, 0.17). At the 6-month follow-up, participants with PAD randomized to control or placebo significantly declined in 6-minute walk distance (-10.2 m; 95% confidence interval, -18.2 to -2.2; P = .013), but improved maximal treadmill walking distance (+25.7 m; 95% CI, +6.0 to +45.3 m; P = .010; difference between change in 6-minute walk versus maximal treadmill walking distance: -37.3 m; 95% CI, -56.4 to -18.2; P < .001). Home-based exercise improved the 6-minute walk distance by 43.2 m (95% CI, +28.4 to +57.9), and supervised treadmill exercise improved the 6-minute walk distance by 25.0 m (95% CI, +14.7 to +35.2; mean difference, +18.2 m favoring home-based exercise [95% CI, +0.2 to +36.2 m; P = .048]). Among all participants, the presence (vs absence) of treadmill exercise training was associated with a 141.3-m greater improvement in maximal treadmill walking distance compared to 6-minute walk distance (95% CI, 88.2-194.4; P < .001), suggesting a benefit from treadmill training on the treadmill outcome. CONCLUSIONS: Maximal treadmill walking distance and the 6-minute walk distance are not interchangeable outcomes in participants with PAD. Participants with PAD randomized to control groups improved treadmill walking distance but simultaneously meaningfully declined in 6-minute walk distance. Supervised treadmill exercise training amplified improvement in treadmill walking distance because of a training to the outcome measure phenomenon.

Association of six-minute walk distance with subsequent lower extremity events in peripheral artery disease.

The prognostic significance of the six-minute walk distance for lower extremity events in people with peripheral artery disease (PAD) is unknown. This longitudinal study assessed whether a poorer six-minute walk distance at baseline was associated with higher rates of subsequent lower extremity atherosclerotic disease events in PAD. A total of 369 patients (mean age 69.4 ± 10.0 years; mean ankle-brachial index (ABI) 0.67 ± 0.17; 31% women; 30% black individuals) from Chicago-area medical centers with PAD were enrolled. Participants underwent baseline six-minute walk testing and returned for annual study visits. Lower extremity events consisted of one or more of the following: ABI decline greater than 15% or medical record adjudicated lower extremity revascularization, critical limb ischemia, or amputation. At a mean follow-up of 33.3 months, lower extremity events occurred in 66/123 (53.7%) people in the first (worst) tertile of six-minute walk performance, 55/124 (44.4%) in the second tertile, and 56/122 (45.9%) in the third (best) tertile. After adjusting for age, sex, race, ABI, comorbidities, and other confounders, participants in the first (worst) tertile of six-minute walk distance at baseline had higher rates of lower extremity events during follow-up, compared to those in the best tertile at baseline (HR = 1.74, 95% CI 1.17-2.60, p = 0.0067). Among people with PAD, a poorer six-minute walk distance was associated with higher rates of subsequent lower extremity PAD-related events after adjusting for confounders. Further study is needed to determine whether interventions that improve six-minute walk distance can reduce lower extremity adverse events in people with PAD.