Cognitive impairment in asymptomatic carotid artery stenosis is associated with abnormal segments in the Circle of Willis.

OBJECTIVE: Our group has previously demonstrated that patients with asymptomatic carotid artery stenosis (ACAS) demonstrate cognitive impairment. One proposed mechanism for cognitive impairment in patients with ACAS is cerebral hypoperfusion due to flow-restriction. We tested whether the combination of a high-grade carotid stenosis and inadequate cross-collateralization in the Circle of Willis (CoW) resulted in worsened cognitive impairment. METHODS: Twenty-four patients with high-grade (≥70% diameter-reducing) ACAS underwent carotid duplex ultrasound, cognitive assessment, and 3D time-of-flight magnetic resonance angiography. The cognitive battery consisted of nine neuropsychological tests assessing four cognitive domains: learning and recall, attention and working memory, motor and processing speed, and executive function. Raw cognitive scores were converted into standardized T-scores. A structured interpretation of the magnetic resonance angiography images was performed with each segment of the CoW categorized as being either normal or abnormal. Abnormal segments of the CoW were defined as segments characterized as narrowed or occluded due to congenital aplasia or hypoplasia, or acquired atherosclerotic stenosis or occlusion. Linear regression was used to estimate the association between the number of abnormal segments in the CoW, and individual cognitive domain scores. Significance was set to P < .05. RESULTS: The mean age of the patients was 66.1 ± 9.6 years, and 79.2% (n = 19) were male. A significant negative association was found between the number of abnormal segments in the CoW and cognitive scores in the learning and recall (ß = -6.5; P = .01), and attention and working memory (ß = -7.0; P = .02) domains. There was a trend suggesting a negative association in the motor and processing speed (ß = -2.4; P = .35) and executive function (ß = -4.5; P = .06) domains that did not reach significance. CONCLUSIONS: In patients with high-grade ACAS, the concomitant presence of increasing occlusive disease in the CoW correlates with worse cognitive function. This association was significant in the learning and recall and attention and working memory domains. Although motor and processing speed and executive function also declined numerically with increasing abnormal segments in the CoW, the relationship was not significant. Since flow restriction at a carotid stenosis compounded by inadequate collateral compensation across a diseased CoW worsens cerebral perfusion, our findings support the hypothesis that cerebral hypoperfusion underlies the observed cognitive impairment in patients with ACAS.

Mid-term Surgery Outcomes in Patients With COVID-19: Results From a Nationwide Analysis.

OBJECTIVE: Determine mid-term postoperative outcomes among coronavirus disease 2019 (COVID-19)-positive (+) patients compared with those who never tested positive before surgery. BACKGROUND: COVID-19 is thought to be associated with prohibitively high rates of postoperative complications. However, prior studies have only evaluated 30-day outcomes, and most did not adjust for demographic, clinical, or procedural characteristics. METHODS: We analyzed data from surgeries performed at all Veterans Affairs hospitals between March 2020 and 2021. Kaplan-Meier curves compared trends in mortality and Cox proportional hazards models estimated rates of mortality and pulmonary, thrombotic, and septic postoperative complications between patients with a positive preoperative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test [COVID (+)] and propensity score-matched COVID-negative (-) patients. RESULTS: Of 153,741 surgical patients, 4778 COVID (+) were matched to 14,101 COVID (-). COVID (+) status was associated with higher postoperative mortality ( P <0.0001) with a 6-month survival of 94.2% (95% confidence interval: 93.2-95.2) versus 96.0% (95% confidence interval: 95.7.0-96.4) in COVID (-). The highest mortality was in the first 30 postoperative days. Hazards for mortality and postoperative complications in COVID (+) decreased with increasing time between testing COVID (+) and date of surgery. COVID (+) patients undergoing elective surgery had similar rates of mortality, thrombotic and septic complications, but higher rates of pulmonary complications than COVID (-) patients. CONCLUSIONS: This is the first report of mid-term outcomes among COVID-19 patients undergoing surgery. COVID-19 is associated with decreased overall and complication-free survival primarily in the early postoperative period, delaying surgery by 5 weeks or more reduces risk of complications. Case urgency has a multiplicative effect on short-term and long-term risk of postoperative mortality and complications.

Growing Deficit in New Cancer Diagnoses 2 Years Into the COVID-19 Pandemic: A National Multicenter Study.

BACKGROUND: Large decreases in cancer diagnoses were seen early in the COVID-19 pandemic. However, the evolution of these deficits since the end of 2020 and the advent of widespread vaccination is unknown. METHODS: This study examined data from the Veterans Health Administration (VA) from 1 January 2018 through 28 February 2022 and identified patients with screening or diagnostic procedures or new cancer diagnoses for the four most common cancers in the VA health system: prostate, lung, colorectal, and bladder cancers. Monthly procedures and new diagnoses were calculated, and the pre-COVID era (January 2018 to February 2020) was compared with the COVID era (March 2020 to February 2022). RESULTS: The study identified 2.5 million patients who underwent a diagnostic or screening procedure related to the four cancers. A new cancer was diagnosed for 317,833 patients. During the first 2 years of the pandemic, VA medical centers performed 13,022 fewer prostate biopsies, 32,348 fewer cystoscopies, and 200,710 fewer colonoscopies than in 2018-2019. These persistent deficits added a cumulative deficit of nearly 19,000 undiagnosed prostate cancers and 3300 to 3700 undiagnosed cancers each for lung, colon, and bladder. Decreased diagnostic and screening procedures correlated with decreased new diagnoses of cancer, particularly cancer of the prostate (R = 0.44) and bladder (R = 0.27). CONCLUSION: Disruptions in new diagnoses of four common cancers (prostate, lung, bladder, and colorectal) seen early in the COVID-19 pandemic have persisted for 2 years. Although reductions improved from the early pandemic, new reductions during the Delta and Omicron waves demonstrate the continued impact of the COVID-19 pandemic on cancer care.

Impact of the COVID-19 pandemic on diagnosis of new cancers: A national multicenter study of the Veterans Affairs Healthcare System.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic caused disruptions in treatment for cancer. Less is known about its impact on new cancer diagnoses, where delays could cause worsening long-term outcomes. This study quantifies decreases in encounters related to prostate, lung, bladder and colorectal cancers, procedures that facilitate their diagnosis, and new diagnoses of those cancers in the COVID era compared to pre-COVID era. METHODS: All encounters at Veterans' Affairs facilities nationwide from 2016 through 2020 were reviewed. The authors quantified trends in new diagnoses of cancer and in procedures facilitating their diagnosis, from January 1, 2018 onward. Using 2018 to 2019 as baseline, reductions in procedures and new cancer diagnoses in 2020 were estimated. Calculated absolute and percentage differences in annual volume and observed-to-expected volume ratios were calculated. Heat maps and funnel plots of volume changes were generated. RESULTS: From 2018 through 2020, there were 4.1 million cancer-related encounters, 3.9 million relevant procedures, and 251,647 new cancers diagnosed. Compared to the annual averages in 2018 through 2019, colonoscopies in 2020 decreased by 45% whereas prostate biopsies, chest computed tomography scans, and cystoscopies decreased by 29%, 10%, and 21%, respectively. New cancer diagnoses decreased by 13% to 23%. These drops varied by state and continued to accumulate despite reductions in pandemic-related restrictions. CONCLUSION: The authors identified substantial reductions in procedures used to diagnose cancer and subsequent reductions in new diagnoses of cancer across the United States because of the COVID-19 pandemic. A nomogram is provided to identify and resolve these unmet health care needs and avoid worse long-term cancer outcomes. LAY SUMMARY: The disruptions due to the COVID-19 pandemic have led to substantial reductions in new cancers being diagnosed. This study quantifies those reductions in a national health care system and offers a method for understanding the backlog of cases and the resources needed to resolve them.

COVID-19 Vaccination Associated With Reduced Postoperative SARS-CoV-2 Infection and Morbidity.

OBJECTIVE: The purpose of this study was to determine the effect of COVID-19 vaccination on postoperative mortality, pulmonary and thrombotic complications, readmissions and hospital lengths of stay among patients undergoing surgery in the United States. BACKGROUND: While vaccination prevents COVID-19, little is known about its impact on postoperative complications. METHODS: This is a nationwide observational cohort study of all 1,255 Veterans Affairs facilities nationwide. We compared patients undergoing surgery at least 2 weeks after their second dose of the Pfizer BioNTech or Moderna vaccines, to contemporary propensity score matched controls. Primary endpoints were 30-day mortality and postoperative COVID-19 infection. Secondary endpoints were pulmonary or thrombotic complications, readmissions, and hospital lengths of stay. RESULTS: 30,681 patients met inclusion criteria. After matching, there were 3,104 in the vaccination group (1,903 received the Pfizer BioNTech, and 1,201 received the Moderna vaccine) and 7,438 controls. Full COVID-19 vaccination was associated with lower rates of postoperative 30-day COVID-19 infection (Incidence Rate Ratio and 95% confidence intervals, 0.09 [0.01,0.44]), pulmonary complications (0.54 [0.39, 0.72]), thrombotic complications (0.68 [0.46, 0.99]) and decreased hospital lengths of stay (0.78 [0.69, 0.89]). Complications were also low in vaccinated patients who tested COVID-19 positive before surgery but events were too few to detect a significant difference compared to controls. CONCLUSION: COVID-19 vaccination is associated with lower rates of postoperative morbidity. The benefit is most pronounced among individuals who have never had a COVID-19 infection before surgery.

Learning curve and proficiency metrics for transcarotid artery revascularization.

BACKGROUND: When introduced to a new procedure, physicians improve their performance and reduce their procedural adverse event rates rapidly during the initial cases and then improvement slows, signaling that proficiency has been achieved. Determining when they have acquired proficiency has important implications for procedural innovation, education, credentialing, and patient safety. We analyzed the worldwide experience with transcarotid artery revascularization (TCAR), a hybrid approach to carotid revascularization, to identify the (1) procedural performance measures associated with clinical and technical adverse events; (2) target levels of performance measures that minimize adverse event rates; and (3) number of TCAR cases needed to achieve the target levels for the performance measures. METHODS: The patient, lesion, and physician characteristics were collected for each TCAR procedure performed by each physician worldwide in an international quality assurance database. Four procedural performance measures were recorded for each procedure: flow-reversal time, fluoroscopy time, contrast volume, and total skin-to-skin time. Composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure), occurring within 24 hours were also recorded. Correlations between each performance measure and the clinical and technical adverse event rates were computed. The inflection points in the performance measures were identified at which no further improvements occurred in the adverse event rates. Finally, the minimum number of TCAR cases required to achieve the target performance measure levels was computed. RESULTS: A total of 18,240 procedures performed by 1273 physicians were analyzed. Of the 18,240 patients, 34.9% were women and 62.5% were asymptomatic. The flow-reversal time correlated with clinical adverse events adjusted for age, sex, and symptomatic status (R2 = 0.91; P < .0001) and adjusted technical adverse events (R2 = 0.86; P < .0001). The skin-to-skin time correlated with adjusted technical adverse events (R2 = 0.92; P < .0001). A reduction in flow-reversal times to <13.1 minutes and the skin-to-skin time to <81 minutes did not translate into further improvements in the adverse event rates. A minimum of 26 TCAR cases was required to achieve the target flow-reversal time, and a minimum of 15 cases was required to achieve the target skin-to-skin time. CONCLUSIONS: The flow-reversal time and skin-to-skin time are appropriate performance measures for establishing the level of expertise of physicians as they acquire skills to perform TCAR. A target time of ≤13.1 minutes for flow-reversal and 81 minutes for skin-to-skin time minimized the adverse event rates. Familiarity with the steps involved in performing TCAR was achieved after ≥15 cases, and minimizing clinical adverse events occurred after ≥26 cases.

Transcarotid revascularization outcomes do not differ by patient age or sex.

BACKGROUND: Transcarotid artery revascularization (TCAR) is a hybrid approach to carotid revascularization. Limited information is available on the differences in periprocedural complications and performance measures of TCAR for men compared with women and for older vs younger adults. METHODS: The patient, lesion, and physician characteristics were collected for all TCAR procedures performed by each physician worldwide in an international quality assurance database between March 3, 2009 and May 7, 2020. Clinical composite (ie, death, stroke, transient ischemic attack, myocardial infarction) and technical composite (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, device failure) adverse events within 24 hours of the procedure were recorded. Four performance measures were recorded: flow-reversal time, fluoroscopy time, contrast volume, and skin-to-skin time. Poisson regressions were used to assess the effects of age and sex on the incidence of clinical and technical composite adverse events. Linear regressions were used to compare the four performance measures. RESULTS: A total of 18,240 TCARs were performed by 1273 physicians; 34.9% of the patients were women and 37.5% were symptomatic. The overall incidence of clinical and technical composite adverse events was low. The adjusted clinical (1.62% [95% confidence interval (CI), 1.17%-2.23%] vs 1.35% [95% CI, 1.01%-1.79%]; P = .22) and technical (7.84% [95% CI, 6.85%-8.97%] vs 7.80% [95% CI, 6.94%-8.77%]; P = .93) composite adverse event rates did not vary for women vs men. The adjusted clinical (P = .65) and technical (P = .55) composite adverse event rates also did not vary by age. The adjusted skin-to-skin time was shorter for the women (76.6 minutes; 95% CI, 74.6-78.6) than for the men (77.7 minutes; 95% CI, 75.7-79.6; P = .002). Significant differences were found by age group for fluoroscopy time, flow-reversal time, and skin-to-skin time, although the magnitude of these differences was small (<1 minute for each). CONCLUSIONS: The clinical and technical outcomes of TCAR are not affected by age or sex. We found clinically minor differences in the procedural performance measures when stratified by age and sex. In addition to being safe for younger individuals, TCAR could also be the preferred method for performing carotid stenting in women and older patients, in particular, older women.

Evaluating the optimal training paradigm for transcarotid artery revascularization based on worldwide experience.

BACKGROUND: Transcarotid artery revascularization (TCAR) is a new hybrid approach to carotid artery revascularization. Proctored training on live cases is an effort-, time-, and resource-intensive approach to learning new procedures. We analyzed the worldwide experience with TCAR to develop objective performance metrics for the procedure and compared the effectiveness of training physicians using cadavers or synthetic models to that of traditional in-person training on live cases. METHODS: Physicians underwent one of three mandatory training programs: (1) in-person proctoring on live TCAR procedures, (2) supervised training on human cadavers, and (3) supervised training on synthetic models. The training details and information from all subsequent independently performed TCAR procedures were recorded. The composite clinical adverse events (ie, transient ischemic attack, stroke, myocardial infarction, death) and composite technical adverse events (ie, aborted procedure, conversion to surgery, bleeding, dissection, cranial nerve injury, or device failure, occurring within 24 hours were recorded). Four procedural proficiency measures were recorded: procedure time, flow-reversal time, fluoroscopy time, and contrast volume. We compared the adverse event rates between the procedures performed by physicians after undergoing the three training modes and tested whether the proficiency measures achieved during TCAR after training on cadavers and synthetic models were noninferior to proctored training. RESULTS: From March 3, 2009 to May 7, 2020, 1160 physicians had undergone proctored (19.1%), cadaver-based (27.4%), and synthetic model-based (53.5%) TCAR training and had subsequently performed 17,283 TCAR procedures. The proctored physicians had treated younger patients and more patients with asymptomatic carotid stenosis and had had more prior experience with transfemoral carotid stenting. The overall 24-hour composite clinical and technical adverse event rates, adjusted for age, sex, and symptomatic status, were 1.0% (95% confidence interval, 0.8%-1.3%) and 6.0% (95% confidence interval, 5.4%-6.6%), respectively, and did not differ significantly by training mode. The proficiency measures of cadaver-trained and synthetic model-trained physicians were not inferior to those for the proctored physicians. CONCLUSIONS: We have presented key objective proficiency metrics for performing TCAR and an analytic framework to assess adequate training for the procedure. Training on cadavers or synthetic models achieved clinical outcomes, technical outcomes, and proficiency measures for subsequently performed TCAR procedures similar to those achieved with training using traditional proctoring on live cases.

Lack of association between cognitive impairment and systemic inflammation in asymptomatic carotid stenosis.

BACKGROUND: Asymptomatic carotid atherosclerotic stenosis (ACAS) is associated with cognitive impairment. Systemic inflammation occurs in patients with systemic atherosclerosis and is also associated with cognitive impairment. The goal of this study was to determine if cognitive impairment in patients with ACAS is the result of systemic inflammation. METHODS: A cross-sectional analysis of 104 patients (63 patients with ACAS, 41 controls) with cognitive function and inflammatory biomarker assessments was performed. Venous blood was assayed for proinflammatory biomarkers (IL-1ß, IL-6, IL-6R, IL-8, IL-17, tumor necrosis factor-α, matrix metalloproteinase [MMP]-1, MMP-2, MMP-7, MMP-9, vascular cell adhesion molecule, and high-sensitivity C-reactive protein). The patients also underwent comprehensive cognitive testing to compute five domain-specific cognitive scores per patient. We first assessed the associations between carotid stenosis and cognitive function, and between carotid stenosis and systemic inflammation in separate regression models. We then determined whether cognitive impairments persisted in patients with carotid stenosis after accounting for inflammation by adjusting for inflammatory biomarker levels in a combined model. RESULTS: Patients with ACAS and control patients differed in age, race, coronary artery disease prevalence, and education. Stenosis patients had worse cognitive scores in two domains: learning and memory (P = .05) and motor and processing speed (P = .002). Despite adjusting for inflammatory biomarker levels, patients with ACAS still demonstrated deficits in the domains of learning and memory and motor and processing speed. CONCLUSIONS: Although systemic atherosclerosis-induced inflammation is a well-recognized cause for cognitive impairment, our data suggest that it is not the primary underlying mechanism behind cognitive impairments seen in ACAS. Cognitive impairments in learning and memory and motor and processing speed seen in patients with ACAS persist after adjusting for systemic inflammation. Thus, alternative mechanisms should be explored to account for the observed functional impairments.

Computed tomography angiographic biomarkers help identify vulnerable carotid artery plaque.

OBJECTIVE: The current risk assessment for patients with carotid atherosclerosis relies primarily on measuring the degree of stenosis. More reliable risk stratification could improve patient selection for targeted treatment. We have developed and validated a model to predict for major adverse neurologic events (MANE; stroke, transient ischemic attack, amaurosis fugax) that incorporates a combination of plaque morphology, patient demographics, and patient clinical information. METHODS: We enrolled 221 patients with asymptomatic carotid stenosis of any severity who had undergone computed tomography angiography at baseline and ≥6 months later. The images were analyzed for carotid plaque morphology (plaque geometry and tissue composition). The data were partitioned into training and validation cohorts. Of the 221 patients, 190 had complete records available and were included in the present analysis. The training cohort was used to develop the best model for predicting MANE, incorporating the patient and plaque features. First, single-variable correlation and unsupervised clustering were performed. Next, several multivariable models were implemented for the response variable of MANE. The best model was selected by optimizing the area under the receiver operating characteristic curve (AUC) and Cohen's kappa statistic. The model was validated using the sequestered data to demonstrate generalizability. RESULTS: A total of 62 patients had experienced a MANE during follow-up. Unsupervised clustering of the patient and plaque features identified single-variable predictors of MANE. Multivariable predictive modeling showed that a combination of the plaque features at baseline (matrix, intraplaque hemorrhage [IPH], wall thickness, plaque burden) with the clinical features (age, body mass index, lipid levels) best predicted for MANE (AUC, 0.79), In contrast, the percent diameter stenosis performed the worst (AUC, 0.55). The strongest single variable for discriminating between patients with and without MANE was IPH, and the most predictive model was produced when IPH was considered with wall remodeling. The selected model also performed well for the validation dataset (AUC, 0.64) and maintained superiority compared with percent diameter stenosis (AUC, 0.49). CONCLUSIONS: A composite of plaque geometry, plaque tissue composition, patient demographics, and clinical information predicted for MANE better than did the traditionally used degree of stenosis alone for those with carotid atherosclerosis. Implementing this predictive model in the clinical setting could help identify patients at high risk of MANE.

Safety of the transradial approach to carotid stenting.

BACKGROUND: The multicenter prospective CREST-2 Registry (C2R) provides recent experience in performing carotid artery stenting (CAS) for interventionists to ensure safe performance of CAS. OBJECTIVE: To determine the periprocedural safety of CAS performed using a transradial approach relative to CAS performed using a transfemoral approach. METHODS: Patients with ≥70% asymptomatic and ≥50% symptomatic carotid stenosis, ≤80 years of age and at standard or high risk for carotid endarterectomy (CEA) are eligible for the C2R. The primary endpoint was a composite of severe access-related complications. Comparisons were made using propensity-score matched logistic regression. RESULTS: The mean age of the cohort was 67.6 ± 8.2 years and 1906 (35.1%) were female. Indications for CAS included 4063 (74.9%) for primary atherosclerosis. A total of 2868 (52.8%) cases underwent CAS for asymptomatic disease. Transradial access was used in 213 (3.9%) patients. The transradial cohort had lower use of general anesthesia (1.5% vs. 6.3%, p = 0.007) and higher use of distal embolic protection (96.7% vs. 89.4%, p = 0.0004). There were no significant differences between radial and femoral access groups in terms of a composite of major access-related complications (0% vs. 1.1%) or a composite of periprocedural stroke or death (3.3% vs. 2.4%; OR = 1.4 [confidence intervals 0.6, 3.1]; p = 0.42). CONCLUSION: We found no significant differences in rates of major access-related complications or periprocedural stroke or death with CAS performed using transradial compared to transfemoral access. Our results support incorporation of the transradial approach to clinical trials comparing CAS to other revascularization techniques.

Repetitive Traumatic Brain Injury Among Older Adults.

OBJECTIVE: To determine the incidence of and assess risk factors for repetitive traumatic brain injury (TBI) among older adults in the United States. DESIGN: Retrospective cohort study. SETTING: Administrative claims data obtained from the Centers for Medicare & Medicaid Services' Chronic Conditions Data Warehouse. PARTICIPANTS: Individuals 65 years or older and diagnosed with TBI between July 2008 and September 2012 drawn from a 5% random sample of US Medicare beneficiaries. MAIN MEASURES: Repetitive TBI was identified as a second TBI occurring at least 90 days after the first occurrence of TBI following an 18-month TBI-free period. We identified factors associated with repetitive TBI using a log-binomial model. RESULTS: A total of 38 064 older Medicare beneficiaries experienced a TBI. Of these, 4562 (12%) beneficiaries sustained at least one subsequent TBI over up to 5 years of follow-up. The unadjusted incidence rate of repetitive TBI was 3022 (95% CI, 2935-3111) per 100 000 person-years. Epilepsy was the strongest predictor of repetitive TBI (relative risk [RR] = 1.44; 95% CI, 1.25-1.56), followed by Alzheimer disease and related dementias (RR = 1.32; 95% CI 1.20-1.45), and depression (RR = 1.30; 95% CI, 1.21-1.38). CONCLUSIONS: Injury prevention and fall-reduction interventions could be targeted to identify groups of older adults at an increased risk of repetitive head injury. Future work should focus on injury-reduction initiatives to reduce the risk of repetitive TBI as well as assessment of outcomes related to repetitive TBI.

Revascularization for asymptomatic carotid artery stenosis improves balance and mobility.

OBJECTIVE: Balance and mobility function worsen with age, more so for those with underlying chronic diseases. We recently found that asymptomatic carotid artery stenosis (ACAS) restricts blood flow to the brain and might also contribute to balance and mobility impairment. In the present study, we tested the hypothesis that ACAS is a modifiable risk factor for balance and mobility impairment. Our goal was to assess the effect of restoring blood flow to the brain by carotid revascularization on the balance and mobility of patients with high-grade ACAS (≥70% diameter-reducing stenosis). METHODS: Twenty adults (age, 67.0 ± 9.4 years) undergoing carotid endarterectomy for high-grade stenosis were enrolled. Balance and mobility assessments were performed before and 6 weeks after revascularization. These included the Short Physical Performance Battery, the Berg Balance Scale, the Four Square Step Test, the Dynamic Gait Index (DGI), the Timed Up and Go test, gait speed, the Mini-Balance Evaluation Systems Test (Mini-BESTest), and the Walking While Talking complex test. RESULTS: Consistent with our previous findings, patients demonstrated reduced scores on the Short Physical Performance Battery, Berg Balance Scale, DGI, and Timed Up and Go test and in gait speed. Depending on the outcome measure, 25% to 90% of the patients had scored in the impaired range at baseline. After surgery, significant improvements were observed in the outcome measures that combined walking with dynamic movements, including the DGI (P = .02) and Mini-BESTest (P = .002). The proportion of patients with Mini-BESTest scores indicating a high fall risk had decreased significantly from 90% (n = 18) at baseline to 40% (n = 8) after surgery (P = .02). We used Pearson's correlations to examine the relationship between balance and mobility before surgery and the change after surgery. Patients with lower baseline DGI and Mini-BESTest scores demonstrated the most improvement after surgery (r = -0.59, P = .006; and r = -0.70, P = .001, respectively). CONCLUSIONS: Carotid revascularization improved patients' balance and mobility, especially for measures that combine walking and dynamic movements. The greatest improvements were observed for the patients who had been most impaired at baseline.

Asymptomatic carotid artery stenosis is associated with cerebral hypoperfusion.

OBJECTIVE: We have shown that almost 50% of patients with asymptomatic carotid stenosis (ACS) will demonstrate cognitive impairment. Recent evidence has suggested that cerebral hypoperfusion is an important cause of cognitive impairment. Carotid stenosis can restrict blood flow to the brain, with consequent cerebral hypoperfusion. In contrast, cross-hemispheric collateral compensation through the Circle of Willis, and cerebrovascular vasodilation can also mitigate the effects of flow restriction. It is, therefore, critical to develop a clinically relevant measure of net brain perfusion in patients with ACS that could help in risk stratification and in determining the appropriate treatment. To determine whether ACS results in cerebral hypoperfusion, we developed a novel approach to quantify interhemispheric cerebral perfusion differences, measured as the time to peak (TTP) and mean transit time (MTT) delays using perfusion-weighted magnetic resonance imaging (PWI) of the whole brain. To evaluate the utility of using clinical duplex ultrasonography (DUS) to infer brain perfusion, we also assessed the relationship between the PWI findings and ultrasound-based peak systolic velocity (PSV). METHODS: Structural and PWI of the brain and magnetic resonance angiography of the carotid arteries were performed in 20 patients with ≥70% ACS. DUS provided the PSV, and magnetic resonance angiography provided plaque geometric measures at the stenosis. Volumetric perfusion maps of the entire brain from PWI were analyzed to obtain the mean interhemispheric differences for the TTP and MTT delays. In addition, the proportion of brain volume that demonstrated a delay in TTP and MTT was also measured. These proportions were measured for increasing severity of perfusion delays (0.5, 1.0, and 2.0 seconds). Finally, perfusion asymmetries on PWI were correlated with the PSV and stenosis features on DUS using Pearson's correlation coefficients. RESULTS: Of the 20 patients, 18 had unilateral stenosis (8 right and 10 left) and 2 had bilateral stenoses. The interhemispheric (left-right) TTP delays measured for the whole brain volume identified impaired perfusion in the hemisphere ipsilateral to the stenosis in 16 of the 18 patients. More than 45% of the patients had had ischemia in at least one half of their brain volume, with a TTP delay >0.5 second. The TTP and MTT delays showed strong correlations with PSV. In contrast, the correlations with the percentage of stenosis were weaker. The correlations for the PSV were strongest with the perfusion deficits (TTP and MTT delays) measured for the whole brain using our proposed algorithm (r = 0.80 and r = 0.74, respectively) rather than when measured on a single magnetic resonance angiography slice as performed in current clinical protocols (r = 0.31 and r = 0.58, respectively). CONCLUSIONS: Interhemispheric TTP and MTT delay measured for the whole brain using PWI has provided a new tool for assessing cerebral perfusion deficits in patients with ACS. Carotid stenosis was associated with a detectable reduction in ipsilateral brain perfusion compared with the opposite hemisphere in >80% of patients. The PSV measured at the carotid stenosis using ultrasonography correlated with TTP and MTT delays and might serve as a clinically useful surrogate to brain hypoperfusion in these patients.

A Nation-Wide Review of Elective Surgery and COVID-Surge Capacity.

BACKGROUND: The COVID-19 pandemic has resulted in over 225,000 excess deaths in the United States. A moratorium on elective surgery was placed early in the pandemic to reduce risk to patients and staff and preserve critical care resources. This report evaluates the impact of the elective surgical moratorium on case volumes and intensive care unit (ICU) bed utilization. METHODS: This retrospective review used a national convenience sample to correlate trends in the weekly rates of surgical cases at 170 Veterans Affairs Hospitals around the United States from January 1 to September 30, 2020 to national trends in the COVID-19 pandemic. We reviewed data on weekly number of procedures performed and ICU bed usage, stratified by level of urgency (elective, urgent, emergency), and whether an ICU bed was required within 24 hours of surgery. National data on the proportion of COVID-19 positive test results and mortality rates were obtained from the Center for Disease Control website. RESULTS: 198,911 unique surgical procedures performed during the study period. The total number of cases performed from January 1 to March 16 was 86,004 compared with 15,699 from March 17 to May 17. The reduction in volume occurred before an increase in the percentage of COVID-19 positive test results and deaths nationally. There was a 91% reduction from baseline in the number of elective surgeries performed allowing 78% of surgical ICU beds to be available for COVID-19 positive patients. CONCLUSION: The moratorium on elective surgical cases was timely and effective in creating bed capacity for critically ill COVID-19 patients. Further analyses will allow targeted resource allocation for future pandemic planning.

Low Back Pain and Substance Use: Diagnostic and Administrative Coding for Opioid Use and Dependence Increased in U.S. Older Adults with Low Back Pain.

OBJECTIVE: Low back pain (LBP) is a leading cause of pain and disability. Substance use complicates the management of LBP, and potential risks increase with aging. Despite implications for an aging, diverse U.S. population, substance use and LBP comorbidity remain poorly defined. The objective of this study was to characterize LBP and substance use diagnoses in older U.S. adults by age, gender, and race. DESIGN: Cross-sectional study of a random national sample. SUBJECTS: Older adults including 1,477,594 U.S. Medicare Part B beneficiaries. METHODS: Bayesian analysis of 37,634,210 claims, with 10,775,869 administrative and 92,903,649 diagnostic code assignments. RESULTS: LBP was diagnosed in 14.8±0.06% of those more than 65 years of age, more in females than in males (15.8±0.08% vs. 13.4±0.09%), and slightly less in those more than 85 years of age (13.3±0.2%). Substance use diagnosis varied by substance: nicotine, 9.6±0.02%; opioid, 2.8±0.01%; and alcohol, 1.3±0.01%. Substance use diagnosis declined with advancing age cohort. Opioid use diagnosis was markedly higher for those in whom LBP was diagnosed (10.5%) than for those not diagnosed with LBP (1.5%). Most older adults (54.9%) with an opioid diagnosis were diagnosed with LBP. Gender differences were modest. Relative rates of substance use diagnoses in LBP were modest for nicotine and alcohol. CONCLUSIONS: Older adults with LBP have high relative rates of opioid diagnoses, irrespective of gender or age. Most older adults with opioid-related diagnoses have LBP, compared with a minority of those not opioid diagnosed. In caring for older adults with LBP or opioid-related diagnoses, health systems must anticipate complexity and support clinicians, patients, and caregivers in managing pain comorbidities. Older adults may benefit from proactive incorporation of non-opioid pain treatments. Further study is needed.

Feasibility and effects of high-intensity interval training in older adults living with HIV.

Adults with HIV on therapy can live a normal lifespan but exhibit advanced ageing which includes reduced cardiorespiratory fitness. Our objective was to determine the feasibility and effects of high-intensity interval training (HIIT) combined with resistance training (RT) in older adults with HIV. We conducted a cross-over pilot study within a randomized exercise trial in sedentary adults with HIV ≥50 years of age. First, participants were randomized to 4 months of continuous high-intensity aerobic exercise (AEX) and RT 3x/week or standard of care control. Then, the control group completed 4 months of HIIT + RT (3x/week). Among the 32 individuals enrolled, 26 eligible participants were randomized. Most participants were African American (63%) and male (95%) with a mean (SD) age of 61.5 (6.7) years and VO2peak of 24.5 (4.9) ml/kg/min. Attendance and adherence to both exercise training interventions were high. The clinically significant increases in VO2peak (ml/kg/min) after HIIT (3.09 ±1.04, p=0.02) and AEX (2.09 ±0.72, p=0.01) represented improvements of 17.1% and 7.7%, respectively. Both groups had improvements in exercise endurance (time on the treadmill) and strength (all p< 0.01). This pilot study supports HIIT as an efficient means to deliver high-intensity AEX to improve cardiorespiratory fitness toward the goal of attenuating the accelerated ageing process in adults with HIV.

A Propensity Score Matched Study of the Positive Impact of Infectious Diseases Consultation on Antimicrobial Appropriateness in Hospitalized Patients with Antimicrobial Stewardship Oversight.

Hospital-based antibiotic stewardship (AS) programs provide oversight and guidance for appropriate antimicrobial use in acute care settings. Infectious disease expertise is beneficial in the care of hospitalized patients with infections. The impact of infectious diseases consultation (IDC) on antimicrobial appropriateness in a large tertiary hospital with an established AS program was investigated. This was a cross-sectional study from October 2017 to March 2019 at a large academic hospital with an AS-directed prospective audit and feedback process and multiple IDC services. Antimicrobial appropriateness was adjudicated by an AS team member after antimicrobial start. Antimicrobial appropriateness was compared among antimicrobial orders with and without IDC using propensity score matching and multivariable logistic regression. Analyses were stratified by primary services caring for the patients. There were 10,508 antimicrobial orders from 6,165 unique patient encounters. Overall appropriateness was 92%, with higher appropriateness among patients with IDC versus without IDC (94% versus 84%; P < 0.0001). After propensity score matching and adjustment for certain antibiotics, organisms, syndromes, and locations, IDC was associated with a greater antimicrobial appropriateness odds ratio (OR) of 2.4 (95% confidence interval [CI], 1.9 to 3.0). Stratification by primary service showed an OR of 2.9 (95% CI, 2.1 to 3.8) for surgical specialties and an OR of 1.6 (95% CI, 1.1 to 2.2) for medical specialties. Even with a high overall antimicrobial appropriateness, patients with IDC had greater odds of antimicrobial appropriateness than those without IDC, and this impact was greater in surgical specialties. Infectious diseases consultation can be synergistic with antimicrobial stewardship programs.

Incidence of Postoperative Opioid Overdose and New Diagnosis of Opioid Use Disorder Among US Veterans.

BACKGROUND AND OBJECTIVES: Perioperative exposure to opioids is associated with adverse outcomes. We aim to determine the associations between surgery and subsequent opioid overdose, an acute event, and a new diagnosis of opioid use disorder (OUD), a chronic relapsing disease, in parallel. METHODS: This retrospective cohort study of US veterans used surgery as exposure and the two outcomes were (1) occurrence of overdose and (2) new diagnosis of OUD in the first postoperative year. Surgical group was matched to the reference controls based on the propensity score of having surgery, and matched logistic regression was used to calculate the odds ratio (OR). RESULTS: A total of 261 208 surgical patients were matched to 479 531 controls. Overdose occurred in 1893 (0.7%) of the surgical patients and in 518 (0.1%) of the matched controls in the first postoperative year (OR, 6.71; 95% confidence interval [CI], 5.80-7.75; P < .001). Among patients with no history of OUD, surgery was also associated with a new diagnosis of OUD in the first postoperative year (OR, 1.13; 95% CI, 1.02-1.24; P = .015). DISCUSSION AND CONCLUSIONS: The postoperative period is strongly associated with opioid overdose, but only weakly associated with new diagnosis of OUD. This is likely due to the difficulty of diagnosing OUD in the postoperative period. SCIENTIFIC SIGNIFICANCE: This is the first study that has examined opioid overdose and new-onset OUD in the postoperative period in parallel. Our analysis suggests different risk factors for each, as well as different strengths of association with surgery. More sensitive diagnostic criteria for postoperative OUD are needed to promptly diagnose and treat this condition. (Am J Addict 2020;00:00-00).

Clinical Implications of Asymptomatic Plasmodium falciparum Infections in Malawi.

Background: Asymptomatic Plasmodium falciparum infections are common in Malawi; however, the implications of these infections for the burden of malaria illness are unknown. Whether asymptomatic infections eventually progress to malaria illness, persist without causing symptoms, or clear spontaneously remains undetermined. We identified asymptomatic infections and evaluated the associations between persistent asymptomatic infections and malaria illness. Methods: Children and adults (N = 120) who presented at a health facility with uncomplicated malaria were followed monthly for 2 years. During follow-up visits, participants with malaria symptoms were tested and, if positive, treated. Samples from all visits were tested for parasites using both microscopy and polymerase chain reaction, and all malaria infections underwent genotyping. Cox frailty models were used to estimate the temporal association between asymptomatic infections and malaria illness episodes. Mixed models were used to estimate the odds of clinical symptoms associated with new versus persistent infections. Results: Participants had a median follow-up time of 720 days. Asymptomatic infections were detected during 23% of visits. Persistent asymptomatic infections were associated with decreased risk of malaria illness in all ages (hazard ratio 0.50, P < .001). When asymptomatic infections preceded malaria illness, newly-acquired infections were detected at 92% of subsequent clinical episodes, independent of presence of persistent infections. Malaria illness among children was more likely due to newly-acquired infections (odds ratio, 1.4; 95% confidence interval, 1.3-1.5) than to persistent infections. Conclusions: Asymptomatic P. falciparum infections are associated with decreased incidence of malaria illness, but do not protect against disease when new infection occurs.