Risk Prediction Tools to Improve Patient Selection for Carotid Endarterectomy Among Patients With Asymptomatic Carotid Stenosis

Abstract

IMPORTANCE Randomized clinical trials have demonstrated that patients with asymptomatic carotid stenosis are eligible for carotid endarterectomy (CEA) if the 30-day surgical complication rate is less than 3% and the patient’s life expectancy is at least 5 years. OBJECTIVE To develop a risk prediction tool to improve patient selection for CEA among patients with asymptomatic carotid stenosis. DESIGN, SETTING, AND PARTICIPANTS In this cohort study, veterans 65 years and older who received both carotid imaging and CEA in the Veterans Administration between January 1, 2005, and December 31, 2009 (n = 2325) were followed up for 5 years. Data were analyzed from January 2005 to December 2015. A risk prediction tool (the Carotid Mortality Index [CMI]) based on 23 candidate variables identified in the literature was developed using Veterans Administration and Medicare data. A simpler model based on the number of 4 key comorbidities that were prevalent and strongly associated with 5-year mortality was also developed (any cancer in the past 5 years, chronic obstructive pulmonary disease, congestive heart failure, and chronic kidney disease [the 4C model]). Model performance was assessed using measures of discrimination (eg, area under the curve [AUC])and calibration. Internal validation was performed by correcting for optimism using 500 bootstrapped samples. MAIN OUTCOME AND MEASURE Five-year mortality. RESULTS Among 2325 veterans, the mean (SD) age was 73.74 (5.92) years. The cohort was predominantly male (98.8%) and of white race/ethnicity (94.4%). Overall, 29.5% (n = 687) of patients died within 5 years of CEA. On the basis of a backward selection algorithm, 9 patient characteristics were selected (age, chronic kidney disease, diabetes, chronic obstructive pulmonary disease, any cancer diagnosis in the past 5 years, congestive heart failure, atrial fibrillation, remote stroke or transient ischemic attack, and body mass index) for the final logistic model, which yielded an optimism-corrected AUC of 0.687 for the CMI. The 4C model had slightly worse discrimination (AUC, 0.657) compared with the CMI model; however, the calibration curve was similar to the full model in most of the range of predicted probabilities. CONCLUSIONS AND RELEVANCE According to results of this study, use of the CMI or the simpler 4C model may improve patient selection for CEA among patients with asymptomatic carotid stenosis.

Shifts in gut microbiome and metabolome are associated with risk of recurrent atrial fibrillation

“…To provide a quantitative method for predicting individual risk and RAF probability, a nomogram of the CAAP-AF-Tax model was established ( Figure 4H) and submitted to internal validation as previously reported. 21 The results showed C index = 0.9668 (95% CI: Figure 4I demonstrated good agreement with the probability of RAF. The Hosmer-Lemeshow test revealed non-statistical significance (P = .6318) and suggested inconsiderable departure from the perfect fit.…”

“…Internal validation followed a reported protocol. 21 Meanwhile, the mean of 500 bootstrapped estimates of optimism was subtracted from the initial (full cohort model) estimate of the area under curve (AUC) and Nagelkerke R2 to obtain the bootstrap optimism-corrected estimates of performance.…”

Role of risk scoring systems in predicting life expectancy after carotid endarterectomy in asymptomatic patients

“…After systematic selection and application of inclusion/exclusion criteria, six RSSs were found and analyzed in depth (Tables Is and IIs, Supplementary Material, section S2). [12][13][14][15][16][17] Detailed description of each score in terms of development, calibration, advantage and limits is available in a previous publication. 8 In establishing the Keyhani score to use, the 4C model was preferred over the Carotid Mortality Index (CMI) , due to its better results in terms of J o u r n a l P r e -p r o o f 9 feasibility and calibration.…”

Hypothesis of “stroke-stop” formula: a tool for risk index determination in development of acute cerebrovascular disease in asymptomatic individuals with carotid stenosis

“…Therefore, the criteria for selecting patients for surgical prevention of acute cerebrovascular disease among asymptomatic individuals with carotid stenosis are broadly discussed nowadays [ 13 , 14 ]. There have been several studies, where in addition to atherosclerotic ICA stenosis, the morphological structure of the atherosclerotic plaque was taken into consideration [ 15 – 18 ].…”