Diversity in randomized clinical trials for peripheral artery disease: a systematic review.

BACKGROUND: Significant race and sex disparities exist in the prevalence, diagnosis, and outcomes of peripheral artery disease (PAD). However, clinical trials evaluating treatments for PAD often lack representative patient populations. This systematic review aims to summarize the demographic representation and enrollment strategies in clinical trials of lower-extremity endovascular interventions for PAD. METHODS: Following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched multiple sources (Medline, EMBASE, Cochrane, Clinicaltrials.gov, WHO clinical trial registry) for randomized controlled trials (RCTs), RCT protocols, and peer-reviewed journal publications of RCTs conducted between January 2012 and December 2022. Descriptive analysis was used to summarize trial characteristics, publication or study protocol characteristics, and the reporting of demographic characteristics. Meta-regression was used to explore associations between demographic characteristics and certain trial characteristics. RESULTS: A total of 2,374 records were identified. Of these, 59 met the inclusion criteria, consisting of 35 trials, 14 publications, and 10 protocols. Information regarding demographic representation was frequently missing. While all 14 trial publications reported age and sex, only 4 reported race/ethnicity, and none reported socioeconomic or marital status. Additionally, only 4 publications reported clinical outcomes by demographic characteristics. Meta-regression analysis revealed that 6% more women were enrolled in non-European trials (36%) than in European trials (30%). CONCLUSIONS: The findings of this review highlight potential issues that may compromise the reliability and external validity of study findings in lower-extremity PAD RCTs when applied to the real-world population. Addressing these issues is crucial to enhance the generalizability and impact of clinical trial results in the field of PAD, ultimately leading to improved clinical outcomes for patients in underrepresented populations. REGISTRATION: The systematic review methodology was published in the International Prospective Register of Systematic Reviews (PROSPERO: CRD42022378304).

Recommendations for Statistical Reporting in Cardiovascular Medicine: A Special Report From the American Heart Association.

Statistical analyses are a crucial component of the biomedical research process and are necessary to draw inferences from biomedical research data. The application of sound statistical methodology is a prerequisite for publication in the American Heart Association (AHA) journal portfolio. The objective of this document is to summarize key aspects of statistical reporting that might be most relevant to the authors, reviewers, and readership of AHA journals. The AHA Scientific Publication Committee convened a task force to inventory existing statistical standards for publication in biomedical journals and to identify approaches suitable for the AHA journal portfolio. The experts on the task force were selected by the AHA Scientific Publication Committee, who identified 12 key topics that serve as the section headers for this document. For each topic, the members of the writing group identified relevant references and evaluated them as a resource to make the standards summarized herein. Each section was independently reviewed by an expert reviewer who was not part of the task force. Expert reviewers were also permitted to comment on other sections if they chose. Differences of opinion were adjudicated by consensus. The standards presented in this report are intended to serve as a guide for high-quality reporting of statistical analyses methods and results.

Reducing Nontraumatic Lower-Extremity Amputations by 20% by 2030: Time to Get to Our Feet: A Policy Statement From the American Heart Association.

Nontraumatic lower-extremity amputation is a devastating complication of peripheral artery disease (PAD) with a high mortality and medical expenditure. There are ≈150 000 nontraumatic leg amputations every year in the United States, and most cases occur in patients with diabetes. Among patients with diabetes, after an ≈40% decline between 2000 and 2009, the amputation rate increased by 50% from 2009 to 2015. A number of evidence-based diagnostic and therapeutic approaches for PAD can reduce amputation risk. However, their implementation and adherence are suboptimal. Some racial/ethnic groups have an elevated risk of PAD but less access to high-quality vascular care, leading to increased rates of amputation. To stop, and indeed reverse, the increasing trends of amputation, actionable policies that will reduce the incidence of critical limb ischemia and enhance delivery of optimal care are needed. This statement describes the impact of amputation on patients and society, summarizes medical approaches to identify PAD and prevent its progression, and proposes policy solutions to prevent limb amputation. Among the actions recommended are improving public awareness of PAD and greater use of effective PAD management strategies (eg, smoking cessation, use of statins, and foot monitoring/care in patients with diabetes). To facilitate the implementation of these recommendations, we propose several regulatory/legislative and organizational/institutional policies such as adoption of quality measures for PAD care; affordable prevention, diagnosis, and management; regulation of tobacco products; clinical decision support for PAD care; professional education; and dedicated funding opportunities to support PAD research. If these recommendations and proposed policies are implemented, we should be able to achieve the goal of reducing the rate of nontraumatic lower-extremity amputations by 20% by 2030.

Inappropriate sinus tachycardia: an examination of existing definitions.

AIMS: Inappropriate sinus tachycardia (IST) is a syndrome characterized by an elevated sinus rate unassociated with known physiological, pathological, or pharmacological causes. Despite published consensus documents, IST definitions appear to vary in the literature. In this study, we reviewed IST publications to evaluate IST definition variability and ascertain the degree to which consensus definitions are being adopted. METHODS AND RESULTS: English-language articles in PubMed, Ovid MEDLINE, Ovid Embase, and Google Scholar published from 1 January 1970 to 1 June 2021 with the title terms 'inappropriate sinus tachycardia,' 'non-paroxysmal sinus tachycardia,' or 'permanent sinus tachycardia' were searched. In each, the IST definition used, qualifying characteristics, and publications cited to support each definition were recorded. We identified 138 publications meeting the search criteria. Inappropriate sinus tachycardia definitions were provided in 114 of 138 articles (83%). A majority of definitions (92/114, 81%) used distinct heart rate (HR) thresholds. Among these, the most common threshold was ≥100 beats per minute (BPM) (75/92, 82%), mainly measured at rest (54/92, 59%). Most definitions (47/92, 51%) included a second criterion to qualify for IST; these were most often an HR threshold of 90 BPM measured over 24 h by ambulatory electrocardiogram (37/47, 79%). Diagnosis of exclusion was a common criterion (75/92, 82%) but symptom status was not (41/92, 45%). The 2015 Heart Rhythm Society IST consensus was commonly cited but adopted in only 37% of definitions published after 2015. CONCLUSIONS: Inappropriate sinus tachycardia definitions in current literature are inconsistent, and professional society consensus IST definitions have, to date, had limited impact.

Improved Survival With Extracorporeal Cardiopulmonary Resuscitation Despite Progressive Metabolic Derangement Associated With Prolonged Resuscitation.

BACKGROUND: The likelihood of neurologically favorable survival declines with prolonged resuscitation. However, the ability of extracorporeal cardiopulmonary resuscitation (ECPR) to modulate this decline is unknown. Our aim was to examine the effects of resuscitation duration on survival and metabolic profile in patients who undergo ECPR for refractory ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest. METHODS: We retrospectively evaluated survival in 160 consecutive adults with refractory ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest treated with the University of Minnesota (UMN) ECPR protocol (transport with ongoing cardiopulmonary resuscitation [CPR] to the cardiac catheterization laboratory for ECPR) compared with 654 adults who had received standard CPR in the amiodarone arm of the ALPS trial (Amiodarone, Lidocaine, or Placebo Study). We evaluated the metabolic changes and rate of survival in relation to duration of CPR in UMN-ECPR patients. RESULTS: Neurologically favorable survival was significantly higher in UMN-ECPR patients versus ALPS patients (33% versus 23%; P=0.01) overall. The mean duration of CPR was also significantly longer for UMN-ECPR patients versus ALPS patients (60 minutes versus 35 minutes; P<0.001). Analysis of the effect of CPR duration on neurologically favorable survival demonstrated significantly higher neurologically favorable survival for UMN-ECPR patients compared with ALPS patients at each CPR duration interval <60 minutes; however, longer CPR duration was associated with a progressive decline in neurologically favorable survival in both groups. All UMN-ECPR patients with 20 to 29 minutes of CPR (8 of 8) survived with neurologically favorable status compared with 24% (24 of 102) of ALPS patients with the same duration of CPR. There were no neurologically favorable survivors in the ALPS cohort with CPR ≥40 minutes, whereas neurologically favorable survival was 25% (9 of 36) for UMN-ECPR patients with 50 to 59 minutes of CPR and 19% with ≥60 minutes of CPR. Relative risk of mortality or poor neurological function was significantly reduced in UMN-ECPR patients with CPR duration ≥60 minutes. Significant metabolic changes included decline in pH, increased lactic acid and arterial partial pressure of carbon dioxide, and thickened left ventricular wall with prolonged professional CPR. CONCLUSIONS: ECPR was associated with improved neurologically favorable survival at all CPR durations <60 minutes despite severe progressive metabolic derangement. However, CPR duration remains a critical determinate of survival.

Mortality and Paclitaxel-Coated Devices: An Individual Patient Data Meta-Analysis.

BACKGROUND: Paclitaxel-containing devices (PTXDs) significantly reduce reintervention in patients with symptomatic femoropopliteal peripheral artery disease. A recent aggregate-data meta-analysis reported increased late mortality in patients with peripheral artery disease treated with PTXDs. We performed an individual patient data meta-analysis to evaluate mortality. METHODS: Manufacturers of US Food and Drug Administration-approved and commercially available devices in the United States provided deidentified individual patient data for independent analysis. Cox proportional hazards 1-stage meta-analysis models using intention-to-treat methods were used for the primary analysis. A secondary analysis of recovered missing vital status data was performed. The impact of control crossover to PTXDs, cause-specific mortality, and drug dose mortality were assessed. RESULTS: A total of 2185 subjects and 386 deaths from 8 PTXD trials with 4-year median follow-up were identified. The primary analysis indicated a 38% (95% CI, 6% to 80%) increased relative mortality risk, corresponding to 4.6% absolute increase, at 5 years associated with PTXD use. Control and treatment arm loss to follow-up and withdrawal were 24% and 23%, respectively. With inclusion of recovered vital status data, the excess relative mortality risk was 27% (95% CI, 3%-58%). This observation was consistent across various scenarios, including as-treated analyses, with no evidence of increased risk over time with PTXDs. Mortality risk tended to be increased for all major causes of death. There were no subgroup differences. No drug dose-mortality association was identified. CONCLUSIONS: This individual patient data meta-analysis, based on the most complete available data set of mortality events from PTXD randomized controlled trials, identified an absolute 4.6% increased mortality risk associated with PTXD use.

Effects of Screening Compliance on Long-term Reductions in All-Cause and Colorectal Cancer Mortality.

BACKGROUND & AIMS: Randomized trials have shown that biennial fecal occult blood test (FOBT) screening reduces mortality from colorectal cancer (CRC), but not overall mortality. Differences in benefit for men vs women, and by age, are unknown. We sought to evaluate long-term reduction in all-cause and CRC-specific mortality in men and women who comply with offered screening, and in different age groups, using individual participant data from 2 large randomized trials of biennial FOBT screening, compared with an intention to treat analysis. METHODS: We updated the CRC and all-cause mortality from the Danish CRC screening trial (n = 61,933) through 30 years of follow up and pooled individual participant data with individual 30-year follow-up data from the Minnesota Colon Cancer Control trial (n = 46,551). We compared the biennial screening groups to usual care (controls) in individuals 50-80 years old using Kaplan Meier estimates of relative risks and risk differences, adjusted for study differences in age, sex, and compliance. RESULTS: Through 30 years of follow up, there were 33,478 (71.9%) and 33,479 (72.2%) total deaths and 1023 (2.2%) and 1146 (2.5%) CRC deaths in the biennial screening (n = 46,553) and control groups (n = 46,358), respectively. Among compliers, biennial FOBT screening significantly reduced CRC mortality by 16% (relative risk [RR], 0.84; 95% CI, 0.74-0.96) and all-cause mortality by 2% (RR, 0.98; 95% CI, 0.97-0.99). Among compliers, the reduction in CRC mortality was larger for men (RR, 0.75; 95% CI, 0.62-0.90) than women (RR, 0.91; 95% CI, 0.75-1.09). The largest reduction in CRC mortality was in compliant men 60-69 years old (RR, 0.59; 95% CI, 0.42-0.81) and women 70 years and older (RR, 0.53; 95% CI, 0.30-0.94). CONCLUSIONS: Long-term CRC mortality outcomes of screening among compliers using biennial FOBT are sustained, with a statistically significant reduction in all-cause mortality. The reduction in CRC mortality is greater in men than women-the benefit in women lags that of men by about 10 years.

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.

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.

Continuous Quality Improvement Efforts Increase Survival with Favorable Neurologic Outcome after Out-of-hospital Cardiac Arrest.

OBJECTIVE: To assess system-wide implementation of specific therapies focused on perfusion during cardiopulmonary resuscitation (CPR) and cerebral recovery after Return of Spontaneous Circulation (ROSC). METHODS: Before and after retrospective analysis of an out-of-hospital cardiac arrest database. Implementation trial in the urban/suburban community of Alameda County, California, USA, population 1.6 million, from November 2009-December 2012. Adult patients with non-traumatic out-of-hospital cardiac arrest (OHCA) who received CPR and/or defibrillation. The impedance threshold device was used throughout this study and there was an increased use of mechanical CPR (mCPR) and in-hospital therapeutic hypothermia (HTH). RESULTS: Rates of ROSC, survival to hospital discharge and Cerebral Performance Category (CPC) scores were compared using univariate and multivariable analyses. A total of 2,926 adult non-traumatic patients with OHCA received CPR during the study period. From 2009-2011 to 2012, there was an increase in ROSC from 29.0% to 34.4% (p = 0.003) and a non-significant increase in hospital discharge from 10.2% to 12.0% (p = 0.16). There was a 76% relative increase in survival with favorable neurologic function between the two periods, as determined by CPC ≤ 2, from 4.5% to 7.9% (unadjusted OR = 1.80; CI = 1.31, 2.48; p < 0.001). After adjusting for witnessed arrest, bystander CPR, initial rhythm (VT/VF vs. others), placement of an advanced airway, EMS response time, drugs administered, and age, the OR was 1.61 (1.10, 2.36; p = 0.015). Using a stepwise multivariable logistic regression model, the independent predictors of CPC ≤ 2 were 2012 (vs. 2009-2011; p = 0.022), witnessed arrest (p < 0.001), initial rhythm VT/VF (p < 0.001), and advanced airway (inverse association p < 0.001). Additional analyses of the three prescribed therapies, separately and in combination, demonstrated that for those patients admitted to the hospital, mCPR with HTH had the biggest impact on survival to hospital discharge with CPC ≤ 2. CONCLUSIONS: Specific therapies within a system of care (mCPR, HTH), developed to enhance circulation during CPR and cerebral recovery after ROSC, significantly improved survival by 74% with favorable neurologic function following OHCA.

Extracranial Systemic Embolic Events in Patients With Nonvalvular Atrial Fibrillation: Incidence, Risk Factors, and Outcomes.

BACKGROUND: Nonvalvular atrial fibrillation is a major cause of thromboembolic events. In comparison with atrial fibrillation-related stroke, extracranial systemic embolic events (SEEs) remain poorly defined. METHODS AND RESULTS: All suspected SEEs reported among 37 973 participants of 4 large contemporary randomized clinical trials of anticoagulation in atrial fibrillation were independently readjudicated for clinical and objective evidence of sudden loss of perfusion of a limb or organ. Over 91 746 patient-years of follow-up, 221 SEEs occurred in 219 subjects. The SEE incidence was 0.24 of 100 and stroke incidence was 1.92 of 100 patient-years. In comparison with patients with stroke, those with SEE were more often female (56% versus 47%; P=0.01) and had comparable mean age (73.1±8.5 versus 73.5±8.8 years; P=0.57) and mean CHADS2 scores (2.4±1.3 versus 2.5±1.2; P=0.33). SEEs more frequently involved the lower extremity (58%) than visceral-mesenteric (31%) or upper extremity (10%). SEE-related care involved clinic assessment alone in 5%, 30% were hospitalized without procedures, 60% underwent endovascular or surgical intervention, and 5% underwent amputation. Within 30 days, 54% of patients recovered fully, 20% survived with deficits, and 25% died. Thirty-day mortality was greater after visceral-mesenteric than lower- or upper-extremity SEE (55%, 17%, and 9%, respectively, P≤0.0001). The relative risk of death throughout follow-up was 4.33 (95% confidence interval, 3.29-5.70) after SEE versus 6.79 (95% confidence interval, 6.22-7.41) after stroke in comparison with patients without either event. CONCLUSIONS: SEE constituted 11.5% of clinically recognized thromboembolic events in patients with atrial fibrillation and was associated with high morbidity and mortality. SEE mortality was comparable to that of ischemic stroke and varied by anatomic site.

Impedance Threshold Device Combined With High-Quality Cardiopulmonary Resuscitation Improves Survival With Favorable Neurological Function After Witnessed Out-of-Hospital Cardiac Arrest.

BACKGROUND: The quality of cardiopulmonary resuscitation (CPR) has been recently shown to affect clinical outcome. The Resuscitation Outcomes Consortium (ROC) Prehospital Resuscitation Impedance Valve and Early Versus Delayed Analysis (PRIMED) trial showed no differences in outcomes with an active vs. sham impedance threshold device (ITD), a CPR adjunct that enhances circulation. It was hypothesized the active ITD would improve survival with favorable neurological outcomes in witnessed out-of-hospital cardiac arrest patients when used with high-quality CPR. METHODS AND RESULTS: Using the publicly accessible ROC PRIMED database, a post-hoc analysis was performed on all witnessed subjects with both compression rate and depth data (n=1,808) who received CPR within the study protocol definition of adequate CPR quality (compression rate 80-120/min and depth 4-6 cm; n=929). Demographics were similar between sham and active ITD groups. In witnessed subjects who received quality CPR, survival with favorable neurological function was 11.9% for the active ITD subjects (56/470) vs. 7.4% for the sham (34/459) (odds ratio 1.69 [95% confidence interval 1.08, 2.64]). There were no statistically significant differences for this primary outcome when CPR was performed outside the boundaries of the definition of adequate CPR quality. Multivariable models did not change these associations. CONCLUSIONS: An active ITD combined with adequate-quality conventional CPR has the potential to significantly improve survival after witnessed cardiac arrest. (Circ J 2016; 80: 2124-2132).

Thymosin ß4 increases the potency of transplanted mesenchymal stem cells for myocardial repair.

BACKGROUND: Thymosin ß4 (Tß4) has been shown to enhance the survival of cultured cardiomyocytes. Here, we investigated whether the cytoprotective effects of Tß4 can increase the effectiveness of transplanted swine mesenchymal stem cells (sMSCs) for cardiac repair in a rat model of myocardial infarction (MI). METHODS AND RESULTS: Under hypoxic conditions, cellular damage (lactate dehydrogenase leakage), apoptosis (terminal deoxynucleotidyl transferase dUTP nick end labelingc cells), and caspase-8 activity were significantly lower, whereas B-cell lymphoma-extra large protein expression was significantly higher, in sMSCs cultured with Tß4 (1 µg/mL) than in sMSCs cultured without Tß4, and Tß4 also increased sMSC proliferation. For in vivo experiments, animals were treated with basal medium (MI: n=6), a fibrin patch (Patch: n=6), a patch containing sMSCs (sMSC: n=9), or a patch containing sMSCs and Tß4 (sMSC/Tß4: n=11); Tß4 was encapsulated in gelatin microspheres to extend Tß4 delivery. Four weeks after treatment, echocardiographic assessments of left-ventricular ejection fraction and fractional shortening were significantly better (P<0.05) in sMSC/Tß4 animals (left-ventricular ejection fraction=51.7 ± 1.1%; fractional shortening=26.7 ± 0.7%) than in animals from MI (39 ± 3%; 19.5 ± 1.7%) and Patch (43 ± 1.4%; 21.6 ± 0.9%) groups. Histological assessment of infarct wall thickness was significantly higher (P<0.05) in sMSC/Tß4 animals (50%, [45%, 80%]) than in animals from MI (25%, [20%, 25%]) group. Measurements in sMSC (left-ventricular ejection fraction=45 ± 2.6%; fractional shortening=22.9 ± 1.6%; TH = 43% [25%, 45%]), Patch, and MI animals were similar. Tß4 administration also significantly increased vascular growth, the retention/survival of the transplanted sMSCs, and the recruitment of endogenous c-Kit(+) progenitor cells to the infarcted region. CONCLUSIONS: Extended-release Tß4 administration improves the retention, survival, and regenerative potency of transplanted sMSCs after myocardial injury.

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.

Epidemiology of peripheral arterial disease and critical limb ischemia in an insured national population.

BACKGROUND: Critical limb ischemia (CLI) represents the most severe clinical manifestation of peripheral arterial disease (PAD) and is the major cause of ischemic amputation in the United States. Risk factors and the associated incidence and prevalence of CLI have not been well described in the general population. This study describes the risk factors for PAD progression to CLI and estimates the annual incidence and prevalence of CLI in a representative United States patient cohort. METHODS: This was a retrospective cohort analysis of adults with commercial, Medicare supplemental, or Medicaid health insurance who had at least one PAD or CLI health care claim from January 1, 2003, through December 31, 2008, and 12 months of continuous coverage. Two subgroups of CLI presentation were identified: primary CLI (patients without any prior PAD or subsequent PAD diagnostic code >30 days after CLI diagnostic code) and secondary CLI (patients with prior PAD or subsequent PAD diagnostic codes ≤30 days of a CLI diagnostic code). Patterns of presentation, annual incidence, and prevalence of CLI were stratified by health care plan. Risk factors for progression to CLI were compared by presentation type. RESULTS: From 2003 to 2008, the mean annual incidence of PAD was 2.35% (95% confidence interval [CI], 2.34%-2.36%) and the incidence of CLI was 0.35% (95% CI, 0.34%-0.35%) of the eligible study population, with primary and secondary presentations occurring at similar rates. The mean annualized prevalence of PAD was 10.69% (95% CI, 10.67%10.70%) and the mean annualized prevalence of CLI was 1.33% (95% CI, 1.32%-1.34%) of the eligible study population, and two-thirds of the cases presented as secondary CLI. CLI developed in 11.08% (95% CI, 11.30%-11.13%) of patients with PAD. A multivariable model demonstrated that diabetes, heart failure, stroke, and renal failure were stronger predictors of primary rather than secondary CLI presentation. CONCLUSIONS: These data establish new national estimates of the incidence and prevalence of CLI and define key risk factors that contribute to primary or secondary presentations of CLI within a very large contemporary insured population cohort in the United States.

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.

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.

Increased Coronary Artery Plaque Volume Among Male Marathon Runners.

BACKGROUND: Long-term marathon running improves many cardiovascular risk factors, and is presumed to protect against coronary artery plaque formation. This hypothesis, that long-term marathon running is protective against coronary atherosclerosis, was tested by quantitatively assessing coronary artery plaque using high resolution coronary computed tomographic angiography (CCTA) in veteran marathon runners compared to sedentary control subjects. METHODS: Men in the study completed at least one marathon yearly for 25 consecutive years. All study subjects underwent CCTA, 12-lead electrocardiogram, measurement of blood pressure, heart rate, and lipid panel. A sedentary matched group was derived from a contemporaneous CCTA database of asymptomatic healthy individuals. CCTAs were analyzed using validated plaque characterization software. RESULTS: Male marathon runners (n = 50) as compared with sedentary male controls (n = 23) had increased total plaque volume (200 vs. 126 mm3, p < 0.01), calcified plaque volume (84 vs. 44 mm3, p < 0.0001), and non-calcified plaque volume (116 vs. 82 mm3, p = 0.04). Lesion area and length, number of lesions per subject, and diameter stenosis did not reach statistical significance. CONCLUSION: Long-term male marathon runners may have paradoxically increased coronary artery plaque volume.

Hemodynamics, survival and neurological function with early versus delayed automated head-up CPR in a porcine model of prolonged cardiac arrest.

AIM: To determine if controlled head and thorax elevation, active compression-decompression cardiopulmonary resuscitation (CPR), and an impedance threshold device combined, termed automated head-up positioning CPR (AHUP-CPR), should be initiated early, as a basic (BLS) intervention, or later, as an advanced (ALS) intervention, in a severe porcine model of cardiac arrest. METHODS: Yorkshire pigs (n = 22) weighing ∼40 kg were anesthetized and ventilated. After 15 minutes of untreated ventricular fibrillation, pigs were randomized to AHUP-CPR for 25 minutes (BLS group) or conventional CPR for 10 minutes, followed by 15 minutes of AHUP-CPR (ALS group). Thereafter, epinephrine, amiodarone, and defibrillation were administered. Neurologic function, the primary endpoint, was assessed 24-hours later with a Neurological Deficit Score (NDS, 0 = normal and 260 = worst deficit score or death). Secondary outcomes included return of spontaneous circulation (ROSC), cumulative survival, hemodynamics and epinephrine responsivity. Data, expressed as mean ± standard deviation, were compared using Fisher's Exact, log-rank, Mann-Whitney U and unpaired t-tests. RESULTS: ROSC was achieved in 10/11 pigs with early AHUP-CPR versus 6/11 with delayed AHUP-CPR (p = 0.14), and cumulative 24-hour survival was 45.5% versus 9.1%, respectively (p < 0.02). The NDS was 203 ± 80 with early AHUP-CPR versus 259 ± 3 with delayed AHUP-CPR (p = 0.035). ETCO2, rSO2, and responsiveness to epinephrine were significantly higher in the early versus delayed AHUP-CPR. CONCLUSION: When delivered early rather than late, AHUP-CPR resulted in significantly increased hemodynamics, 24-hour survival, and improved neurological function in pigs after prolonged cardiac arrest. Based on these findings, AHUP-CPR should be considered a BLS intervention.