To Dx Carotid Stenosis, Start With Duplex Ultrasound

Major Finding: In the work-up of a patient with a recent transient ischemic attack or minor ischemic stroke, the most cost-effective strategy is duplex ultrasonography as the initial test, followed by CT angiography if the results are positive. Patients with 70%-99% stenosis should then undergo carotid endarterectomy. For the average 60-year-old man, this strategy had the lowest cost ($51,730) and yielded the largest number of quality-adjusted life years (14.38).

Data Sources: Meta-analysis of 41 studies, review of the literature, and a prospective diagnostic cohort study involving 351 patients.

Disclosures: The study was supported by the National Healthcare Insurance Board of the Netherlands and the Revolving Fund of Erasmus University Medical Center. The investigators stated that they had no financial relationships to disclose.

The most cost-effective strategy to diagnose carotid artery stenosis for most patients with recent transient ischemic attacks or minor strokes is duplex ultrasound, followed (if the results are positive) by CT angiography.

Patients with 70%-99% stenosis should then undergo carotid endarterectomy, according to a study based on a meta-analysis, a review of the literature, and a prospective diagnostic cohort study.

This strategy yields the lowest costs and the largest number of quality-adjusted life-years (QALY) for the average patient, according to analysis by Aletta T.R. Tholen, M.Sc., and colleagues from Erasmus University Medical Center, Rotterdam, the Netherlands (Radiology 2010;256:585-97).

For the typical 60-year-old man, this strategy would cost 39,826 euros (roughly US $51,730 at current exchange rates) and would yield 14.38 QALY. For the typical 60-year-old woman, it would cost 45,911 euros (US $59,634) and would yield 16.46 QALY.

The optimum strategy would differ somewhat for patients with higher risk profiles or a high probability of carotid artery stenosis, or for those who can undergo surgery without delay. In those cases, the duplex ultrasonography can be dispensed with in favor of CT angiography and surgery for 50%-99% stenosis.

For both men and women, the least cost-effective diagnostic strategy was duplex ultrasonography performed as a solo test. Duplex ultrasonography followed by contrast-enhanced MR angiography was intermediate in cost effectiveness, but was clearly dominated by duplex ultrasound followed by CT angiography.

The investigators used a decision-tree model to assess all feasible strategies in normal practice. They based their estimates of the prior probability of carotid artery stenosis on the results of a cross-sectional prospective diagnostic cohort study of 351 patients with a transient ischemic attack or minor stroke who were admitted to Erasmus University Medical Center between November 2002 and January 2005.

Of those patients, 9.8% of the males and 2.2% of the females had 70%-99% stenosis. Another 2.1% of the male patients and 1.4% of the female patients had 50%-69% stenosis.

In estimating the performances of the diagnostic tests, investigators relied on a meta-analysis that included 2,541 patients in a total of 41 studies published between January 1987 and April 2004. They based their information of the disadvantages of the various tests on their diagnostic cohort study and from a review of the literature.

“Our results suggest that if the patient cannot undergo surgery in a timely fashion, an initial duplex US examination and a 70%-99% stenosis criterion for surgery is indicated. On the other hand, if the patient can undergo surgery in a timely fashion, immediate CT-angiography and the use of a lenient criterion (50%-99% stenosis) as the surgery indication is beneficial,” the researchers concluded.

Major Finding: In the work-up of a patient with a recent transient ischemic attack or minor ischemic stroke, the most cost-effective strategy is duplex ultrasonography as the initial test, followed by CT angiography if the results are positive. Patients with 70%-99% stenosis should then undergo carotid endarterectomy. For the average 60-year-old man, this strategy had the lowest cost ($51,730) and yielded the largest number of quality-adjusted life years (14.38).

Data Sources: Meta-analysis of 41 studies, review of the literature, and a prospective diagnostic cohort study involving 351 patients.

Disclosures: The study was supported by the National Healthcare Insurance Board of the Netherlands and the Revolving Fund of Erasmus University Medical Center. The investigators stated that they had no financial relationships to disclose.

The most cost-effective strategy to diagnose carotid artery stenosis for most patients with recent transient ischemic attacks or minor strokes is duplex ultrasound, followed (if the results are positive) by CT angiography.

Patients with 70%-99% stenosis should then undergo carotid endarterectomy, according to a study based on a meta-analysis, a review of the literature, and a prospective diagnostic cohort study.

This strategy yields the lowest costs and the largest number of quality-adjusted life-years (QALY) for the average patient, according to analysis by Aletta T.R. Tholen, M.Sc., and colleagues from Erasmus University Medical Center, Rotterdam, the Netherlands (Radiology 2010;256:585-97).

For the typical 60-year-old man, this strategy would cost 39,826 euros (roughly US $51,730 at current exchange rates) and would yield 14.38 QALY. For the typical 60-year-old woman, it would cost 45,911 euros (US $59,634) and would yield 16.46 QALY.

The optimum strategy would differ somewhat for patients with higher risk profiles or a high probability of carotid artery stenosis, or for those who can undergo surgery without delay. In those cases, the duplex ultrasonography can be dispensed with in favor of CT angiography and surgery for 50%-99% stenosis.

For both men and women, the least cost-effective diagnostic strategy was duplex ultrasonography performed as a solo test. Duplex ultrasonography followed by contrast-enhanced MR angiography was intermediate in cost effectiveness, but was clearly dominated by duplex ultrasound followed by CT angiography.

The investigators used a decision-tree model to assess all feasible strategies in normal practice. They based their estimates of the prior probability of carotid artery stenosis on the results of a cross-sectional prospective diagnostic cohort study of 351 patients with a transient ischemic attack or minor stroke who were admitted to Erasmus University Medical Center between November 2002 and January 2005.

Of those patients, 9.8% of the males and 2.2% of the females had 70%-99% stenosis. Another 2.1% of the male patients and 1.4% of the female patients had 50%-69% stenosis.

In estimating the performances of the diagnostic tests, investigators relied on a meta-analysis that included 2,541 patients in a total of 41 studies published between January 1987 and April 2004. They based their information of the disadvantages of the various tests on their diagnostic cohort study and from a review of the literature.

“Our results suggest that if the patient cannot undergo surgery in a timely fashion, an initial duplex US examination and a 70%-99% stenosis criterion for surgery is indicated. On the other hand, if the patient can undergo surgery in a timely fashion, immediate CT-angiography and the use of a lenient criterion (50%-99% stenosis) as the surgery indication is beneficial,” the researchers concluded.

Major Finding: In the work-up of a patient with a recent transient ischemic attack or minor ischemic stroke, the most cost-effective strategy is duplex ultrasonography as the initial test, followed by CT angiography if the results are positive. Patients with 70%-99% stenosis should then undergo carotid endarterectomy. For the average 60-year-old man, this strategy had the lowest cost ($51,730) and yielded the largest number of quality-adjusted life years (14.38).

Data Sources: Meta-analysis of 41 studies, review of the literature, and a prospective diagnostic cohort study involving 351 patients.

Disclosures: The study was supported by the National Healthcare Insurance Board of the Netherlands and the Revolving Fund of Erasmus University Medical Center. The investigators stated that they had no financial relationships to disclose.

The most cost-effective strategy to diagnose carotid artery stenosis for most patients with recent transient ischemic attacks or minor strokes is duplex ultrasound, followed (if the results are positive) by CT angiography.

Patients with 70%-99% stenosis should then undergo carotid endarterectomy, according to a study based on a meta-analysis, a review of the literature, and a prospective diagnostic cohort study.

This strategy yields the lowest costs and the largest number of quality-adjusted life-years (QALY) for the average patient, according to analysis by Aletta T.R. Tholen, M.Sc., and colleagues from Erasmus University Medical Center, Rotterdam, the Netherlands (Radiology 2010;256:585-97).

For the typical 60-year-old man, this strategy would cost 39,826 euros (roughly US $51,730 at current exchange rates) and would yield 14.38 QALY. For the typical 60-year-old woman, it would cost 45,911 euros (US $59,634) and would yield 16.46 QALY.

The optimum strategy would differ somewhat for patients with higher risk profiles or a high probability of carotid artery stenosis, or for those who can undergo surgery without delay. In those cases, the duplex ultrasonography can be dispensed with in favor of CT angiography and surgery for 50%-99% stenosis.

For both men and women, the least cost-effective diagnostic strategy was duplex ultrasonography performed as a solo test. Duplex ultrasonography followed by contrast-enhanced MR angiography was intermediate in cost effectiveness, but was clearly dominated by duplex ultrasound followed by CT angiography.

The investigators used a decision-tree model to assess all feasible strategies in normal practice. They based their estimates of the prior probability of carotid artery stenosis on the results of a cross-sectional prospective diagnostic cohort study of 351 patients with a transient ischemic attack or minor stroke who were admitted to Erasmus University Medical Center between November 2002 and January 2005.

Of those patients, 9.8% of the males and 2.2% of the females had 70%-99% stenosis. Another 2.1% of the male patients and 1.4% of the female patients had 50%-69% stenosis.

In estimating the performances of the diagnostic tests, investigators relied on a meta-analysis that included 2,541 patients in a total of 41 studies published between January 1987 and April 2004. They based their information of the disadvantages of the various tests on their diagnostic cohort study and from a review of the literature.

“Our results suggest that if the patient cannot undergo surgery in a timely fashion, an initial duplex US examination and a 70%-99% stenosis criterion for surgery is indicated. On the other hand, if the patient can undergo surgery in a timely fashion, immediate CT-angiography and the use of a lenient criterion (50%-99% stenosis) as the surgery indication is beneficial,” the researchers concluded.