Body mass index and outcome after revascularization for symptomatic carotid artery stenosis

The Body Mass Index as a Determinant of Acute Ischemic Location in Mild Non-cardioembolic Stroke Patients

Objective Although the body mass index (BMI) is considered a meaningful parameter for evaluating obesity, the association between the BMI and acute non-cardioembolic stroke remains unclear. We investigated how the BMI was related to patients' background, type of infarction, and infarction location in patients with non-cardioembolic stroke using an acute dual study (ADS) cohort. Methods The ADS trial was conducted between May 2011 and June 2017 in Japan. The BMI classifications were those proposed by the World Health Organization classification: underweight, <18.5 kg/m2; normal weight, 18.5-24.9 kg/m2; overweight, 25-29.9 kg/m2; and obese, ≥30 kg/m2. Results Data from 1,136 patients were analyzed. The median BMI was 23.6 kg/m2 (interquartile range: 21.6-25.8 kg/m2), with a BMI ≥30 kg/m2 in 63 patients (6%), 25-29.9 kg/m2 in 321 (28%), 18.5-24.9 kg/m2 in 692 (61%), and <18.5 kg/m2 in 60 (5%). The group with a BMI ≥30 kg/m2 was the youngest, and the group with a BMI <18.5 kg/m2 was the oldest (p<0.001). The proportion of patients with a history of hypertension (p<0.001), diabetes (p<0.001), dyslipidemia (p<0.001), and statin therapy (p=0.005) increased with increasing BMI. Pontine infarcts were frequent in the following order: obese, overweight, normal weight, and underweight (24%, 18%, 14%, and 13%, respectively; p=0.034). In contrast, cortical infarct were frequent in the order of underweight, normal weight, overweight, and obese at 20%, 19%, 14%, and 3%, respectively (p=0.007). Conclusion Acute stroke patients with a high BMI have more atherosclerosis-related factors in their backgrounds than those with lower BMIs. In addition, the BMI may be a determinant of infarct location in patients with acute stroke.

High body mass index is associated with elevated risk of perioperative ischemic stroke in patients who underwent noncardiac surgery: A retrospective cohort study

BACKGROUND

Body mass index (BMI) serves as a global metric for assessing obesity and overall health status. However, the impact of BMI, treated as a continuous variable, on the risk of perioperative stroke remains poorly understood. This retrospective cohort study aimed to elucidate the association between BMI and the risk of perioperative ischemic stroke in patients undergoing non-cardiovascular surgery.

METHODS

A cohort of 223,415 patients undergoing noncardiac surgery at the First Medical Center of Chinese PLA General Hospital between January 1, 2008 and August 31, 2019 was screened. Preoperative high BMI, defined as BMI >22.64 kg/m2, was the primary exposure, and the outcome of interest was the new diagnosis of perioperative ischemic stroke within 30 days post-surgery. Robust controls for patient and intraoperative factors were implemented to minimize residual confounding. Logistic regression and propensity score matching were employed, and patients were stratified into subgroups for further investigation.

RESULTS

The overall incidence of perioperative ischemic stroke was 0.23% (n = 525) in the cohort. After adjusting for patient-related variables (OR 1.283; 95% CI, 1.04-1.594; p < 0.05), surgery-related variables (OR 1.484; 95% CI, 1.2-1.849; p < 0.001), and all confounding variables (OR 1.279; 95% CI, 1.025-1.607; p < 0.05), patients with BMI >22.64 kg/m2 exhibited a significantly increased risk of perioperative ischemic stroke. This association persisted in the propensity score matched cohort (OR 1.577; 95% CI, 1.203-2.073; p < 0.01). Subgroup analyses indicated that preoperative BMI >22.64 kg/m2 correlated with an elevated risk of perioperative ischemic stroke in female patients, those with coronary heart disease, peripheral vascular diseases, and individuals undergoing neurosurgery.

CONCLUSION

We first identified BMI >22.64 kg/m2 as a substantial and independent risk factor for perioperative ischemic stroke in Chinese noncardiac surgery patients. Normal BMI may not suffice as a universal preventive standard. Instead, a more stringent perioperative weight management approach is recommended, particularly for specific subgroups such as female patients, those with coronary heart disease and peripheral vascular disease, and individuals scheduled for neurosurgery.

Transcarotid revascularization in obese patients

OBJECTIVE

Transcarotid revascularization (TCAR) is a minimally invasive hybrid surgical carotid stenting technique which utilizes cerebral flow reversal as embolic protection during carotid lesion manipulation. This investigation was performed to define the perioperative risks associated with this operation in the obese patient.

METHODS

A retrospective review of tandem carotid revascularization databases maintained at two high-volume health systems was performed to capture all TCARs performed between 2015 and 2022. A threshold of body mass index of 35 kg/m2 defined the "obese" patient. Demographics, intraoperative, perioperative, and follow-up characteristics were compared using univariate analysis.

RESULTS

We performed 793 TCAR procedures that qualified for study inclusion within the prespecified time. After applying our obesity definition, 129 patients qualified as obese and were compared to the remainder. There were no significant differences in baseline demographics as comparable Charlson Comorbidity Indices were noted between groups; however, obese patients had a significantly higher prevalence of hypertension, hyperlipidemia, and diabetes. Intraoperative, case complexity in the obese patients did not seem to be increased, as measured by operative time (68.4 ± 23.0 vs 64.2 ± 25.8 min, p = 0.09), fluoroscopic time (4.9 ± 3.2 vs 4.6 ± 3.6 min, p = 0.38), and estimated blood loss (40.6 ± 49.0 vs 46.6 ± 49.4 min, p = 0.22). Similarly, no disparities were observed with respect to ipsilateral stroke (3.1 vs. 1.7%, p = 0.29), contralateral stroke (0 vs. 0.2%, p > 0.99), death (0 vs. 1.1%, p = 0.61), and stroke/death (3.1 vs. 3.0%, p > 0.99) in the 30-day perioperative period. Both cohorts were followed for approximately 1 year (12.0 ± 13.4 vs 11.6 ± 13.4 months, p = 0.76). During this period, rates of ipsilateral stroke (3.1% vs. 2.7%, p > 0.99), contralateral stroke (1.1 vs. 0.8%, p > 0.99), and death (4.7 vs. 6.2%, p = 0.68) were similar.

CONCLUSIONS

TCAR performed in the obese population was not more challenging by intraoperative characteristics and did not result in a statistically higher incidence of adverse events in the perioperative phase.

Body Mass Index and Late Adverse Outcomes after a Carotid Endarterectomy

A cohort study was conducted to examine the association of an increased body mass index (BMI) with late adverse outcomes after a carotid endarterectomy (CEA). It comprised 1597 CEAs, performed in 1533 patients at the Vascular Surgery Clinic in Belgrade, from 1 January 2012 to 31 December 2017. The follow-up lasted four years after CEA. Data for late myocardial infarction and stroke were available for 1223 CEAs, data for death for 1305 CEAs, and data for restenosis for 1162 CEAs. Logistic and Cox regressions were used in the analysis. The CEAs in patients who were overweight and obese were separately compared with the CEAs in patients with a normal weight. Out of 1223 CEAs, 413 (33.8%) were performed in patients with a normal weight, 583 (47.7%) in patients who were overweight, and 220 (18.0%) in patients who were obese. According to the logistic regression analysis, the compared groups did not significantly differ in the frequency of myocardial infarction, stroke, and death, as late major adverse outcomes (MAOs), or in the frequency of restenosis. According to the Cox and logistic regression analyses, BMI was neither a predictor for late MAOs, analyzed separately or all together, nor for restenosis. In conclusion, being overweight and being obese were not related to the occurrence of late adverse outcomes after a carotid endarterectomy.

Body mass index and early outcomes after carotid endarterectomy

As the existing data on the correlation of adiposity with adverse outcomes of carotid endarterectomy (CEA) are inconsistent, the aim of the present study is to examine the correlation of an increased body mass index with 30-day complications after carotid endarterectomy. The cohort study comprises 1586 CEAs, performed at the Clinic for Vascular Surgery in Belgrade, from 2012-2017. Out of them, 550 CEAs were performed in patients with normal body mass index (18.5-24.9), 750 in overweight (25.0-29.9), and 286 in obese (≥30) patients. The association of overweight and obesity with early outcomes of carotid endarterectomy was assessed using univariate and multivariate logistic regression analysis. Overweight patients, in whom CEAs were performed, were significantly more frequently males, compared to normal weight patients-Odds Ratio (OR) 1.51 (95% confidence interval- 1.19-1.89). Moreover, overweight patients significantly more frequently had non-insulin-dependent diabetes mellitus-OR 1.44 (1.09-1.90), and more frequently used ACEI in hospital discharge therapy-OR 1.41 (1.07-1.84) than normal weight patients. Additionally, the CEAs in them were less frequently followed by bleedings-OR 0.37 (0.16-0.83). Compared to normal weight patients, obese patients were significantly younger-OR 0.98 (0.96-0.99), and with insulin-dependent and non-insulin-dependent diabetes mellitus-OR 1.83 (1.09-3.06) and OR 2.13 (1.50-3.01) respectively. They also more frequently had increased triglyceride levels-OR 1.36 (1.01-1.83), and more frequently used oral anticoagulants in therapy before the surgery-OR 2.16 (1.11-4.19). According to the results obtained, overweight and obesity were not associated with an increased death rate, transient ischemic attack (TIA), stroke, myocardial infarction, or with minor complications, and the need for reoperation after carotid endarterectomy. The only exception was bleeding, which was significantly less frequent after CEA in overweight compared to normal weight patients.

Guideline on carotid surgery for stroke prevention: updates from the Italian Society of Vascular and Endovascular Surgery. A trend towards personalized medicine

BACKGROUND

This guideline (GL) on carotid surgery as updating of "Stroke: Italian guidelines for Prevention and Treatment" of the ISO-SPREAD Italian Stroke Organization-Group, has recently been published in the National Guideline System and shared with the Italian Society of Vascular and Endovascular Surgery (SICVE) and other Scientific Societies and Patient's Association.

METHODS

GRADE-SIGN version, AGREE quality of reporting checklist. Clinical questions formulated according to the PICO model. Recommendations developed based on clinical questions by a multidisciplinary experts' panel and patients' representatives. Systematic reviews performed for each PICO question. Considered judgements filled by assessing the evidence level, direction, and strength of the recommendations.

RESULTS

The panel provided indications and recommendations for appropriate, comprehensive, and individualized management of patients with carotid stenosis. Diagnostic and therapeutic processes of the best medical therapy, carotid endarterectomy (CEA), carotid stenting (CAS) according to the evidences and the judged opinions were included. Symptomatic carotid stenosis in elective and emergency, asymptomatic carotid stenosis, association with ischemic heart disease, preoperative diagnostics, types of anesthesia, monitoring in case of CEA, CEA techniques, comparison between CEA and CAS, post-surgical carotid restenosis, and medical therapy are the main topics, even with analysis of uncertainty areas for risk-benefit assessments in the individual patient (personalized medicine [PM]).

CONCLUSIONS

This GL updates on the main recommendations for the most appropriate diagnostic and medical-surgical management of patients with atherosclerotic carotid artery stenosis to prevent ischemic stroke. This GL also provides useful elements for the application of PM in good clinical practice.

Outcomes for Adults with Metabolic Syndrome Undergoing Elective Carotid Endarterectomy

BACKGROUND

Metabolic syndrome (MetS) is a disorder characterized by a constellation of cardiometabolic risk factors including abdominal obesity, dyslipidemia, hypertension, and glucose intolerance that has been associated with adverse perioperative outcomes. We evaluated outcomes for patients with MetS after carotid endarterectomy (CEA) in the largest population to date.

METHODS

We performed a matched cohort analysis using clinical data from 2012 to 2018 in the American College of Surgeons National Surgical Quality Improvement Program. We used propensity scores to match patients to attain covariate balance and used logistic regression to assess odds of unfavorable outcomes, including a predefined primary outcome of composite cardiovascular incident.

RESULTS

We identified 50,423 eligible adult patients, of whom 14.2% qualified for MetS (n = 7156). Patients with MetS tended to have CEA at an earlier age, more functional dependence, and longer operative durations. After matching, MetS remained associated with the primary outcome of combined cardiovascular incident (odds ratio [OR], 1.42; 95% confidence interval [CI], 1.18-1.72; P < 0.001), stroke (OR, 1.44; 95% CI, 1.12-1.85; P = 0.004), prolonged length of stay (OR, 1.31; 95% CI, 1.18-1.44; P < 0.001), and discharge to facility (OR, 1.32; 95% CI, 1.08-1.61; P = 0.007). We also found that obesity alone is protective against combined cardiovascular incident, whereas hypertension with diabetes and MetS increase odds of a cardiovascular complication.

CONCLUSIONS

Metabolic syndrome is associated with adverse outcomes for adult patients undergoing elective CEA.

Which BMI for Diabetes Patients is Better? From the View of the Adipose Tissue Macrophage-Derived Exosome

PURPOSE

Diabetes, as a group of metabolic diseases, can elevate blood glucose, thus leading to the development of life-threatening complications. It is difficult to define the outcome for diabetics with different BMI. This review will illustrate the adipose tissue macrophage-derived exosome in the diabetics with different BMI.

PATIENTS AND METHODS

Insulin resistance in peripheral tissues can cause diabetes. The peripheral tissues include liver, muscle, or the adipose depots. Communication between these organs is fatal to the maintenance of glucose homeostasis. This review will illustrate this communication. Obesity is closely linked with diabetes. There are different changes in fat distribution in diabetic patients. Adipose tissue macrophages can secrete various hormones, including adiponectin, leptin, resistin and other classical cytokines, such as TNF-α and IL-6. Studies illustrated that exosomes from the adipose tissue, can modulate inter-organ cross-talk by regulating gene expression in other tissues.

RESULTS

Adipose tissue macrophages exosomes links thin and fat individuals in the development of diabetes.

CONCLUSION

The molecular pathways initiated by exosomes such as miRNA in the situations of metabolic stress could help us gain a deeper knowledge of the pathophysiology of diabetes.

The Association of Body Mass Index with Outcomes after Carotid Endarterectomy

BACKGROUND

Patients who are obese or underweight are traditionally at higher risk for perioperative morbidity and mortality. The effect of body mass index (BMI) on outcomes after carotid endarterectomy (CEA) is unclear. Our goal was to analyze the association of BMI with perioperative and long-term outcomes after elective CEA.

METHODS

The Vascular Quality Initiative (VQI) database was queried from 2003-2018 for patients undergoing elective CEAs. Patients were categorized into 5 BMI cohorts - underweight (UW, BMI < 18.5 kg/m²), normal weight (NW, BMI 18.5-24.9 kg/m²), overweight (OW, BMI 25-29.9 kg/m²), obese (OB, BMI 30-39.9 kg/m²), and morbidly obese (MO, BMI ≥ 40 kg/m²). Perioperative and long-term outcomes were assessed with univariable and multivariable analyses.

RESULTS

There were 89,079 patients included: 2% UW, 26% NW, 38.4% OW, 29.9% OB, and 3.6% MO. Overall, the mean age was 70.6 years, 60% were male, and 91.8% were of white race. There were significant differences among the BMI cohorts in regards to age, sex, smoking status, and comorbidities (all P < 0.05). For perioperative outcomes, the BMI cohorts differed significantly in reoperation for bleeding and 30-day mortality. On multivariable analysis, BMI was not associated with stroke or perioperative mortality. MO was associated with perioperative cardiac complications (Odds Ratios [OR] 1.26, 95% CI 1-1.57, P = 0.05). UW status was associated with increased return to the operating room (OR 1.89, 95% confidence interval [95% CI] 1.28-2.78, P = 0.001), 30-day mortality (OR 1.68, 95% CI 1-2.86, P =0.05), 1-year mortality (Hazard ratio [HR] 1.37, 95% CI 1.08-1.74, P = 0.01), and 5-year mortality (HR 1.22, 95% CI 1.06-1.41, P =0.005).

CONCLUSIONS

BMI status was not associated with perioperative stroke, cranial nerve injury, or surgical site infections. Patients with MO had higher perioperative cardiac complications. UW patients have lower short and long-term survival and should be a focus for long-term targeted risk factor stratification and modification.

Carotid Revascularization: Current Practice and Future Directions

Carotid stenosis is responsible for approximately 15% of ischemic strokes. Carotid revascularization significantly decreases patients' stroke risk. Carotid endarterectomy has first-line therapy for moderate-to-severe carotid stenosis after a series of pivotal randomized controlled trials were published almost 30 years ago. Revascularization with carotid stenting has become a popular and effective alternative in a select subpopulation of patients. We review the current state of the literature regarding revascularization indications, patient selection, advantages of each revascularization approach, timing of intervention, and emerging interventional techniques, such as transcarotid artery revascularization.

Increased Body Mass Index Associated With Reduced Risk of Delayed Cerebral Ischemia and Subsequent Infarction After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Increased body mass index (BMI) may be protective against cerebral ischemia in certain clinical contexts.

OBJECTIVE

To investigate whether increased BMI was associated with delayed cerebral ischemia (DCI) and subsequent infarction after aneurysmal subarachnoid hemorrhage (aSAH).

METHODS

We retrospectively reviewed the clinical course of patients presenting to our institution for management of aSAH. Patient were segregated according to BMI< or ≥29.4, a value determined by Classification and Regression Tree analysis. Predictors of DCI and delayed infarction were identified using stepwise multivariate logistic regression analysis.

RESULTS

There were 161 patients included for analysis. Average BMI within our patient cohort was 28.9, with 67 patients presenting with a BMI of ≥29.4 on admission. DCI occurred in 50 patients (31.1%) and was complicated by delayed infarction in 15 patients (9.3%). On stepwise multivariate analysis, BMI ≥ 29.4 was independently associated with reduced likelihood of DCI (odds ratio [OR] 0.42, 95% confidence interval [CI] 0.18-0.92) and delayed infarction (OR 0.13, 95% CI 0.02-0.61; P = .008). Increasing maximum flow velocity on transcranial Doppler ultrasound was independently associated with increased odds of both DCI (Unit OR 1.19, 95% CI 1.09-1.30; P < .001) and delayed infarction (Unit OR 1.31, 95% CI 1.13-1.56; P < .001), while intracerebral hemorrhage was independently associated with increased odds of delayed infarction (OR 6.99, 95% CI 1.82-30.25; P = .005).

CONCLUSION

We report an association between elevated BMI and reduced incidence of DCI and delayed infarction, suggesting a protective effect of increasing BMI on the risk of ischemic complications after aSAH.

High Operator and Hospital Volume Are Associated With a Decreased Risk of Death and Stroke After Carotid Revascularization: A Systematic Review and Meta-analysis

OBJECTIVE

To examine the association between operator or hospital volume and procedural outcomes of carotid revascularization.

BACKGROUND

Operator and hospital volume have been proposed as determinants of outcome after carotid endarterectomy (CEA) or carotid artery stenting (CAS). The magnitude and clinical relevance of this relationship are debated.

METHODS

We systematically searched PubMed and EMBASE until August 21, 2017. The primary outcome was procedural (30 days, in-hospital, or perioperative) death or stroke. Obtained or estimated risk estimates were pooled with a generic inverse variance random-effects model.

RESULTS

We included 87 studies. A decreased risk of death or stroke following CEA was found for high compared to low operator volume with a pooled adjusted odds ratio (OR) of 0.50 (95% confidence interval [CI] 0.28-0.87; 3 cohorts), and a pooled unadjusted relative risk (RR) of 0.59 (95% CI 0.42-0.83; 9 cohorts); for high compared to low hospital volume with a pooled adjusted OR of 0.62 (95% CI 0.42-0.90; 5 cohorts), and a pooled unadjusted RR of 0.68 (95% CI 0.51-0.92; 9 cohorts). A decreased risk of death or stroke after CAS was found for high compared to low operator volume with an adjusted OR of 0.43 (95% CI 0.20-0.95; 1 cohort), and an unadjusted RR of 0.50 (95% CI 0.32-0.79; 1 cohort); for high compared to low hospital volume with an adjusted OR of 0.46 (95% CI 0.26-0.80; 1 cohort), and no significant decreased risk in a pooled unadjusted RR of 0.72 (95% CI 0.49-1.06; 2 cohorts).

CONCLUSIONS

We found a decreased risk of procedural death and stroke after CEA and CAS for high operator and high hospital volume, indicating that aiming for a high volume may help to reduce procedural complications.

REGISTRATION

This systematic review has been registered in the international prospective registry of systematic reviews (PROSPERO): CRD42017051491.

Male patients with diabetes undergoing coronary artery bypass grafting have increased major adverse cerebral and cardiovascular events

OBJECTIVES

The role of body mass index (BMI) in the prognosis of patients with diabetes undergoing coronary artery bypass grafting (CABG) has been of great interest for a long time. However, the precise relationship between BMI and major adverse cerebral and cardiovascular events (MACCEs) in these patients is still unclear. The goal of this study was to investigate the outcome of patients with diabetes with different BMIs undergoing CABG and the results from the 5-year follow-up.

METHODS

This study included 771 patients with diabetes undergoing CABG from 1 January 2003 to 31 December 2009. They were classified based on the Chinese standard for BMI as follows: underweight: <18.5 kg/m2; normal weight: 18.5-23.9 kg/m2; overweight: 24-27.9 kg/m2; and obese: >28 kg/m2. Short-term outcomes and 5-year MACCEs were compared among various BMI groups after surgery.

RESULTS

Obese and overweight patients with diabetes tended to be younger than normal weight patients [57 years (49-64) vs 62 years (54-68) and 64 years (59-69); P < 0.001]. There were fewer male patients (25.20% vs 17.78% and 16.54%, P = 0.041). More smokers were in the 2 groups (38.8% vs 51.55% and 57.14%, P < 0.001). Glucose concentration was highest in the overweight group [6.40 (5.40-7.80) vs 6.96 (5.69-8.22) and 6.80 (5.90-8.40); P = 0.041)]. Cox regression analysis of the 5-year follow-up data indicated that various BMI groups were not associated with significant differences in 5-year MACCEs; however, male sex was the risk factor for MACCEs (hazard ratio 1.83, 95% confidence interval 1.11-3.04; P = 0.019).

CONCLUSIONS

The BMI of the patients with diabetes undergoing CABG had no effect on MACCEs. Male sex was the risk factor in these patients.

Editor's Choice - Overview of Primary and Secondary Analyses From 20 Randomised Controlled Trials Comparing Carotid Artery Stenting With Carotid Endarterectomy

OBJECTIVES

The aim of this review was to carry out primary and secondary analyses of 20 randomised controlled trials (RCTs) comparing carotid endarterectomy (CEA) with carotid artery stenting (CAS).

METHODS

A systematic review and meta-analysis of data from 20 RCTs (126 publications) was carried out.

RESULTS

Compared with CEA, the 30 day death/stroke rate was significantly higher after CAS in seven RCTs involving 3467 asymptomatic patients (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02-2.64) and in 10 RCTs involving 5797 symptomatic patients (OR 1.71, 95% CI 1.38-2.11). Excluding procedural risks, late ipsilateral stroke was about 4% at 9 years for both CEA and CAS, i.e., CAS was durable. Reducing procedural death/stroke after CAS may be achieved through better case selection, e.g., performing CEA in (i) symptomatic patients aged > 70 years; (ii) interventions within 14 days of symptom onset; and (iii) situations where stroke risk after CAS is predicted to be higher (segmental/remote plaques, plaque length > 13 mm, heavy burden of white matter lesions [WMLs], where two or more stents might be needed). New WMLs were significantly more common after CAS (52% vs. 17%) and were associated with higher rates of late stroke/transient ischaemic attack (23% vs. 9%), but there was no evidence that new WMLs predisposed towards late cognitive impairment. Restenoses were more common after CAS (10%) but did not increase late ipsilateral stroke. Restenoses (70%-99%) after CEA were associated with a small but significant increase in late ipsilateral stroke (OR 3.87, 95% CI 1.96-7.67; p < .001).

CONCLUSIONS

CAS confers higher rates of 30 day death/stroke than CEA. After 30 days, ipsilateral stroke is virtually identical for CEA and CAS. Key issues to be resolved include the following: (i) Will newer stent technologies and improved cerebral protection allow CAS to be performed < 14 days after symptom onset with risks similar to CEA? (ii) What is the optimal volume of CAS procedures to maintain competency? (iii) How to deliver better risk factor control and best medical treatment? (iv) Is there a role for CEA/CAS in preventing/reversing cognitive impairment?

Challenge and Yield of Enrolling Racially and Ethnically Diverse Patient Populations in Low Event Rate Clinical Trials

BACKGROUND AND PURPOSE

We report patient enrollment and retention by race and ethnicity in the CREST (Carotid Revascularization Endarterectomy Versus Stent Trial) and assess potential effect modification by race/ethnicity. In addition, we discuss the challenge of detecting differences in study outcomes when subgroups are small and the event rate is low.

METHODS

We compared 2502 patients by race, ethnicity, baseline characteristics, and primary outcome (any periprocedural stroke, death, or myocardial infarction and subsequent ipsilateral stroke up to 10 years).

RESULTS

Two hundred forty (9.7%) patients were minority by race (6.1%) or ethnicity (3.6%); 109 patients (4.4%) were black, 32 (1.3%) Asian, 2332 (93.4%) white, 11 (0.4%) other, and 18 (0.7%) unknown. Ninety (3.6%) were Hispanic, 2377 (95%) non-Hispanic, and 35 (1.4%) unknown. The rate of the primary end point for all patients was 10.9%±0.9% at 10 years and did not differ by race or ethnicity (P_inter>0.24).

CONCLUSIONS

The proportion of minorities recruited to CREST was below their representation in the general population, and retention of minority patients was lower than for whites. Primary outcomes did not differ by race or ethnicity. However, in CREST (like other studies), the lack of evidence of a racial/ethnic difference in the treatment effect should be interpreted with caution because of low statistical power to detect such a difference.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.