There is evidence that coronary collaterals improve the prognosis in patients with acute myocardial infarction(MI). However, there is limited clinical information on the protective role of collaterals in patients with...There is evidence that coronary collaterals improve the prognosis in patients with acute myocardial infarction(MI). However, there is limited clinical information on the protective role of collaterals in patients with stable coronary artery disease. This information may help risk stratification and the development of novel therapies, such as arteriogenesis and angiogenesis. The relation between collaterals and cardiac death or MI at 1 year after coronary revascularization was studied in 561 patients who were enrolled in a randomized study that compared stent implantation with bypass grafting. Collaterals were assessed on an angiogram using Rentrop’s classification and considered present with a Rentrop grade>1. Unadjusted and adjusted odds ratios for cardiac death or MI at 1 year were calculated using univariate and multivariate regression analyses. In addition, determinants of collaterals were assessed using univariate and multivariate analyses. Collaterals were present in 176 patients(31%). The adjusted odds ratio of cardiac death or infarction was 0.18(95%confidence interval 0.04 to 0.78) in the presence of collaterals. Independent determinants of collaterals were age(odds ratio 0.97, 95%confidence interval 0.95 to 0.99), multivessel disease(odds ratio 1.60, 95%confidence interval 1.02 to 2.51), impaired ventricular function(odds ratio 1.85, 95%confidence interval 1.04 to 3.29), type C lesion(odds ratio 3.72, 95%confidence interval 2.33 to 5.95), and stenosis severity >90%(odds ratio 9.08, 95%confidence interval 4.65 to 17.73). In conclusion, in patients with a low risk profile, the presence of collaterals protects against cardiac death and MI at 1 year after coronary revascularization. Variables that reflect the duration and severity of the atherosclerotic and ischemic burden determine their presence.展开更多
Background: Extensive investigations are often performed to reveal the cause of chronic polyneuropathy. It is not known whether a restrictive diagnostic guideline improves cost efficiency without loss of diagnostic re...Background: Extensive investigations are often performed to reveal the cause of chronic polyneuropathy. It is not known whether a restrictive diagnostic guideline improves cost efficiency without loss of diagnostic reliability. Methods: In a prospective multicentre study, a comparison was made between the workup in patients with chronic polyneuropathy before and after guideline implementation. Results: Three hundred and ten patients were included: 173 before and 137 after g uideline implementation. In all patients, the diagnosis would remain the same if the workup was limited to the investigations in the guideline. After guideline implementation, the time to reach a diagnosis decreased by two weeks. There was a reduction of 33%in the number and costs of routine laboratory inves tigations/patient, and a reduction of 27%in the total number of laboratory tests/patient, despite low guideline adherence. Conclusion: The implementation of a diagnostic guideline for chronic polyneuropathy can reduce diagnostic delay an d the number and costs of investigations for each patient without loss of diag nostic reliability. Continuous evaluation strategies after guideline implementat ion may improve guideline adherence and cost efficiency.展开更多
Background and Purpose -To evaluate duplex ultrasonographic thresholds for the determination of 70%to 99%stenosis of the ipsilateral and contralateral internal carotid artery in patients with symptoms of amaurosis fug...Background and Purpose -To evaluate duplex ultrasonographic thresholds for the determination of 70%to 99%stenosis of the ipsilateral and contralateral internal carotid artery in patients with symptoms of amaurosis fugax, transient ischemic attack (TIA), or minor stroke based on 2 criteria: maximizing accuracy and optimizing cost-effectiv- eness and to compare these with current recommendations. Methods -From January 1997 to January 2000, a prospective multicenter study was conducted including 350 consecutive patients with symptoms of amaurosis fugax, TIA, or minor stroke who underwent bilateral duplex ultrasonography and digital subtraction angiograp hy. A linear regression analysis was performed to estimate the degree of angiogr aphic stenosis as a function of the peak systolic velocity (PSV). PSV thresholds were calculated for the ipsilateral and contralateral carotid arteries based on maximizing accuracy and optimizing cost-effectiveness. Results -The PSV measu rements significantly overestimated the angiographic stenosis in the contralater al artery (9.5%; 95%CI, 6.3%to 12.7%) compared with the ipsilateral carotid artery. The recommended PSV threshold for the diagnosis of 70%to 99%stenosis i s 230 cm/s. Maximizing accuracy, the optimal PSV threshold for the ipsilateral a rtery was 280 cm/s, and for the contralateral artery, 370 cm/s for diagnosing a 70%to 99%stenosis. Optimizing cost-effectiveness, the optimal PSV threshold was 220 cm/s for ipsilateral and 290 cm/s for contralateral carotid arteries. Conclusions -PSV measurements overestimate the degree of angiographic stenosis in the contralateral carotid artery in patients with symptoms of amaurosis fugax, TIA, or minor stroke. Separate PSV thresholds should be used for the ipsilateral and contralateral carotid artery. PSV thresholds that optimize cost-effectiveness differ from the recommended thresholds and from thresholds that maximize accuracy.展开更多
文摘There is evidence that coronary collaterals improve the prognosis in patients with acute myocardial infarction(MI). However, there is limited clinical information on the protective role of collaterals in patients with stable coronary artery disease. This information may help risk stratification and the development of novel therapies, such as arteriogenesis and angiogenesis. The relation between collaterals and cardiac death or MI at 1 year after coronary revascularization was studied in 561 patients who were enrolled in a randomized study that compared stent implantation with bypass grafting. Collaterals were assessed on an angiogram using Rentrop’s classification and considered present with a Rentrop grade>1. Unadjusted and adjusted odds ratios for cardiac death or MI at 1 year were calculated using univariate and multivariate regression analyses. In addition, determinants of collaterals were assessed using univariate and multivariate analyses. Collaterals were present in 176 patients(31%). The adjusted odds ratio of cardiac death or infarction was 0.18(95%confidence interval 0.04 to 0.78) in the presence of collaterals. Independent determinants of collaterals were age(odds ratio 0.97, 95%confidence interval 0.95 to 0.99), multivessel disease(odds ratio 1.60, 95%confidence interval 1.02 to 2.51), impaired ventricular function(odds ratio 1.85, 95%confidence interval 1.04 to 3.29), type C lesion(odds ratio 3.72, 95%confidence interval 2.33 to 5.95), and stenosis severity >90%(odds ratio 9.08, 95%confidence interval 4.65 to 17.73). In conclusion, in patients with a low risk profile, the presence of collaterals protects against cardiac death and MI at 1 year after coronary revascularization. Variables that reflect the duration and severity of the atherosclerotic and ischemic burden determine their presence.
文摘Background: Extensive investigations are often performed to reveal the cause of chronic polyneuropathy. It is not known whether a restrictive diagnostic guideline improves cost efficiency without loss of diagnostic reliability. Methods: In a prospective multicentre study, a comparison was made between the workup in patients with chronic polyneuropathy before and after guideline implementation. Results: Three hundred and ten patients were included: 173 before and 137 after g uideline implementation. In all patients, the diagnosis would remain the same if the workup was limited to the investigations in the guideline. After guideline implementation, the time to reach a diagnosis decreased by two weeks. There was a reduction of 33%in the number and costs of routine laboratory inves tigations/patient, and a reduction of 27%in the total number of laboratory tests/patient, despite low guideline adherence. Conclusion: The implementation of a diagnostic guideline for chronic polyneuropathy can reduce diagnostic delay an d the number and costs of investigations for each patient without loss of diag nostic reliability. Continuous evaluation strategies after guideline implementat ion may improve guideline adherence and cost efficiency.
文摘Background and Purpose -To evaluate duplex ultrasonographic thresholds for the determination of 70%to 99%stenosis of the ipsilateral and contralateral internal carotid artery in patients with symptoms of amaurosis fugax, transient ischemic attack (TIA), or minor stroke based on 2 criteria: maximizing accuracy and optimizing cost-effectiv- eness and to compare these with current recommendations. Methods -From January 1997 to January 2000, a prospective multicenter study was conducted including 350 consecutive patients with symptoms of amaurosis fugax, TIA, or minor stroke who underwent bilateral duplex ultrasonography and digital subtraction angiograp hy. A linear regression analysis was performed to estimate the degree of angiogr aphic stenosis as a function of the peak systolic velocity (PSV). PSV thresholds were calculated for the ipsilateral and contralateral carotid arteries based on maximizing accuracy and optimizing cost-effectiveness. Results -The PSV measu rements significantly overestimated the angiographic stenosis in the contralater al artery (9.5%; 95%CI, 6.3%to 12.7%) compared with the ipsilateral carotid artery. The recommended PSV threshold for the diagnosis of 70%to 99%stenosis i s 230 cm/s. Maximizing accuracy, the optimal PSV threshold for the ipsilateral a rtery was 280 cm/s, and for the contralateral artery, 370 cm/s for diagnosing a 70%to 99%stenosis. Optimizing cost-effectiveness, the optimal PSV threshold was 220 cm/s for ipsilateral and 290 cm/s for contralateral carotid arteries. Conclusions -PSV measurements overestimate the degree of angiographic stenosis in the contralateral carotid artery in patients with symptoms of amaurosis fugax, TIA, or minor stroke. Separate PSV thresholds should be used for the ipsilateral and contralateral carotid artery. PSV thresholds that optimize cost-effectiveness differ from the recommended thresholds and from thresholds that maximize accuracy.
