The patient with transient cerebral ischemia: a golden opportunity for stroke prevention.

Transient ischemic attack (TIA) provides a golden opportunity for stroke prevention. TIA should be treated as a medical emergency with prompt investigations to determine the mechanism of ischemia and subsequent preventive therapy. The risk of stroke after TIA is estimated to be 10%-20% in the first 90 days. The risk is time-dependent with 50% of the risk accruing in the first 48 hours. In this review, we describe the diagnosis and management of TIA, introduce new concepts in TIA and suggest that all patients with significant TIA should undergo rapid investigation and management to prevent stroke.

Who doesn't receive carotid endarterectomy when appropriate?

OBJECTIVE: The purpose of this study was to identify clinical and nonclinical factors associated with failure to perform carotid endarterectomy (CEA) in patients with clinically appropriate indications. We analyzed data from a prospective cohort study performed at five Veterans Affairs medical centers. Patients were referred for carotid artery evaluation if they had at least 50% stenosis in one carotid artery, had no history of CEA, and were independently classified preoperatively as appropriate candidates for CEA, according to clinical criteria. The primary outcome was receipt of CEA within 6 months of evaluation. Data were collected by medical record review and interview regarding clinical status, and patient and physician perception of the risks and benefits of CEA. RESULTS: Among clinically appropriate candidates for CEA, 66.8% (n = 233) did not undergo the operation. Compared with patients who did undergo CEA, a greater proportion of these patients had no symptoms (68.7% vs 45.7%; P <.001). A twofold greater proportion of patients who did not undergo CEA were in the highest quartile of reported aversion to surgery. Moreover, a fourfold greater proportion were perceived by their physicians to be at less than 5% risk for future stroke without the operation, and more than a twofold greater proportion were believed to experience less than 5% efficacy from the operation by their providers (P <.01). In multivariable analyses, four characteristics were significantly associated with whether an appropriate candidate did not receive CEA: asymptomatic disease, less than 70% stenosis, high expressed aversion to surgery score, and low (<5%) provider-perceived efficacy of the operation. CONCLUSION: Among patients in the Veterans Affairs health care system who are clinically appropriate candidates for CEA, those who did not receive the operation were less likely to have symptomatic disease or high-grade carotid artery stenosis, but were more likely to report high aversion to surgery and to have a provider who believed CEA would not be efficacious.

Contrast-enhanced magnetic resonance angiography of carotid arteries: utility in routine clinical practice.

BACKGROUND AND PURPOSE: Contrast-enhanced magnetic resonance angiography (CEMRA) is among the newer noninvasive tests used for the evaluation of patients with carotid artery disease. Evidence supporting its utility in routine clinical practice is lacking. METHODS: The results of CEMRA were compared with those of catheter angiography in 50 consecutive patients being evaluated for carotid endarterectomy (CEA) at a community hospital. Using indications for CEA based on published guidelines, we determined the rate of misclassification for surgery, sensitivity, specificity, and positive and negative predictive values. In addition, the interrater agreement (kappa score) of CEMRA was compared with that of catheter angiography in the studied population and with interpretations provided by 2 blinded radiologists. RESULTS: Compared with catheter angiography, 24% (95% CI, 12% to 36%) of patients would have been misclassified for CEA on the basis of CEMRA results alone. CEMRA was associated with sensitivity of 92%, specificity of 62%, positive predictive value of 78%, and negative predictive value of 89%. When both CEMRA and duplex Doppler ultrasound were performed and the results were concordant, the misclassification rate decreased to 17% (95% CI, 2% to 32%). kappa scores were similar for CEMRA and catheter angiography (0.72 and 0.75, respectively). CONCLUSIONS: CEMRA was found to be highly sensitive for detection of surgically amenable carotid stenosis. kappa scores for the interpretation of CEMRA and catheter angiography were similar. However, clinicians should be cautious when using CEMRA alone for surgical decision making in CEA candidates because a significant number of patients may be misclassified. The rate of misclassification is reduced when the results of CEMRA and duplex Doppler ultrasound are concordant.

Carotid endarterectomy and race: do clinical indications and patient preferences account for differences?

BACKGROUND AND PURPOSE: Carotid endarterectomy (CE) has been proved to reduce the risk of stroke for certain patients, but black patients are less likely than whites to receive CE. The purpose of this work was to determine the importance of clinical indications and patient preferences in predicting the use of carotid angiography and CE in a racially stratified sample of patients. METHODS: Between 1997 and 1999, 708 patients with at least 1 carotid artery containing a >/=50% stenosis were enrolled (617 whites, 91 blacks) from 5 Veteran Affairs Medical Centers. Patient interviews were conducted at the time of the index carotid ultrasound, and each patient was followed up for 6 months to determine clinical events and receipt of carotid angiography or CE. RESULTS: Black and white patients were similar in terms of age, sex, education level, and social support. More black than white patients received ultrasound for a completed stroke (36% versus 13%), and fewer black patients were classified as asymptomatic (56% versus 70%) or as having had a TIA (8% versus 17%; P<0.001). Health-related quality of life scores, trust in physician, and medical comorbidity scores were similar for black and white patients. Black patients expressed higher aversion to CE than white patients (31% versus 15% in the highest aversion quartile for blacks and whites, respectively; P=0.01). During follow-up, 20% of white patients and 14% of black patients received CE (P=0.19). In adjusted analyses, only patient clinical status as it relates to the indication for CE and site were associated with receipt of CE. CONCLUSIONS: Contrary to prior research, patient's race was not associated with receipt of invasive carotid imaging or CE for older male veterans. These findings persist after controlling for patient preferences, comorbid illness, and quality of life. For patients enrolled in an equal-access health care system, clinical status was the primary determinant of the receipt of CE.

Utility of noninvasive studies in the evaluation of patients with carotid artery disease.

Endarterectomy reduces the risk of stroke in selected patients with carotid artery stenosis, and the benefit is related to the degree of stenosis. Although the randomized trials demonstrating this benefit measured the degree of stenosis with conventional catheter angiography, many physicians are relying on noninvasive tests to select patients for surgery. Technologic advancement in this area is outpacing the availability of quality data supporting the clinical utility of the newer noninvasive tests.