Asymptomatic carotid stenosis and unrelated operations: should we be more aggressive?

Impact of Real-World Adherence with Best Medical Treatment on Cost-Effectiveness of Carotid Endarterectomy for Asymptomatic Carotid Artery Stenosis

BACKGROUND

To present a model of decision and cost-effectiveness analysis that allows assessing the trade-off between the short-term risks of performing a carotid endarterectomy (CEA) and the rate of preventable future events and the impact of real-world adherence of best medical treatment (BMT) on cost-effectiveness of both therapeutic options.

METHODS

We used data from the current literature to define values for a base case and perform a sensitivity analysis. The primary end point was a comparison of the fatal and disabling stroke-free survival during a 5-year period in a cohort of hypothetical patients who presented asymptomatic severe carotid stenosis and were treated with either prophylactic CEA or adherent and nonadherent best medical treatment, respectively.

RESULTS

The difference in estimated fatal and disabling stroke-free survival favoring endarterectomy in patients with asymptomatic severe carotid stenosis is 44 days over the course of 5 years in case of nonadherent best medical treatment. Over a 5-year time horizon, prophylactic CEA would be cost-effective in 50.8% of bootstrap replicates and nonpersistent BMT might be economically dominant in 11.1%. The probability that CEA would be cost-effective at a willingness-to-pay (WTP) threshold of Euro 50,000/quality-adjusted life year gained was 71.8%. In 17.9% prophylactic CEA would be more costly and effective than persistent BMT, but its incremental cost-effectiveness ratio was greater than the WTP, so persistent BMT would be optimal.

CONCLUSIONS

In this model, in case of real-world drug adherence, it was likely that a strategy of early endarterectomy might be a cost-effective or even the dominant therapeutic option in comparison with a strategy of medical therapy alone (deferred surgery). If background any-territory stroke rates on contemporary medical therapy would fall substantially below 0.7%, surgery would cease to be cost-effective.

[Mortality and morbidity of consecutive surgical carotid revascularisations in octogenarians]

AIM OF THE STUDY

Retrospective evaluation of the immediate and mid term mortality and morbidity of carotid surgical revascularisations in a population of octogenarians with severe carotid artery stenosis.

MATERIAL AND METHOD

Retrospective study of all patients 80 years old and more, consecutively operated for an internal carotid artery stenosis, from January 1991 to December 2003, in the Unit of Vascular Surgery of the Civil Hospices of Strasbourg. We analyzed the perioperative death and stroke rates at 30 days and the mid term survival.

RESULTS

We performed 81 carotid revascularisations on 70 patients. The mean age of the population studied was 83.5 (+/-2.8 years), (range 80-92). Twenty-four stenoses (29.6%) were symptomatic (23 transient ischemic accidents, 1 stroke), and 57 stenoses (70.4%) were asymptomatic. The mean degree of stenosis was 89.2+/-8.1% (based on NASCET evaluation). The main cardiovascular risk factor was arterial hypertension (95.7%). The overall perioperative death and stroke rate was 7.1%: 2 deaths, one of them related to a stroke, and 3 strokes (confidence interval: 2.4-15.9%). The perioperative death and stroke rate in the symptomatic stenosis group was 0%, and 8.8% in the asymptomatic stenosis group (p=0.163). No specific risk factor of neurologic events has been found except ASA 3 or higher (RR: 3.84 [1.2-12.1]). The mean follow up was 3.6 years (range 2-11.3), no patient was lost to follow-up. The Kaplan-Meier 5-year survival was 52%. The mean time to death was 3.5 years after the operation. Only 16.7% of these deaths were stroke-related.

CONCLUSIONS

Multicentric prospective studies, which have determined current recommendations for carotid surgery, did not include patients aged 79 years and older. In this particular population, the good results observed in our institution in the symptomatic carotid stenosis group would support the use of surgical treatment. The perioperative death and stroke rate observed for the asymptomatic group, clearly superior to current recommendations, suggests in our experience and especially for ASA> or =3, an individual evaluation to determinate the best indication.

Prospective Randomized Study on Asymptomatic Severe Carotid Stenosis and Perioperative Stroke Risk in Patients Undergoing Major Vascular Surgery: Prophylactic or Deferred Carotid Endarterectomy?

We compared the perioperative (30-day) stroke risk in asymptomatic patients with severe carotid stenosis who underwent carotid endarterectomy (CEA) before or after major vascular surgery. Seventy-nine patients with asymptomatic severe carotid lesion were randomly assigned to group I (n = 40) or group II (n = 39) to receive prophylactic CEA (within 1 week before major surgery) or deferred CEA (between 30 days and 6 months after major surgery), respectively. All procedures were eversion CEAs performed under deep general anesthesia and cerebral protection involving continuous electroencephalographic monitoring for selective shunting. There were no perioperative deaths or strokes relating to the major surgical procedure in either group. All group II patients underwent deferred CEA as planned (median 47 days, range 38-94) with no subsequent perioperative deaths or strokes. Two of these patients (5.1%) suffered a minor stroke, however, 65 and 78 days after their major surgical procedure, while awaiting carotid revascularization. Although data emerging from this analysis indicate that severe asymptomatic carotid disease may be safely postponed in patients undergoing major noncarotid vascular surgery, only a multicenter prospective study could determine the most appropriate management of this subset of patients.

Risk for stroke after elective noncarotid vascular surgery

INTRODUCTION

Patients undergoing operations to treat peripheral vascular disease have systemic atherosclerosis and are at risk for stroke. However, the incidence and effect of cerebrovascular events on noncarotid vascular surgical outcomes are not well-defined.

METHODS

Patients undergoing common operations for vascular disease from 1997 to 2000 were examined with data from the Veterans Affairs (VA) National Surgery Quality Improvement Project and the VA patient treatment files. Operations studied included abdominal aortic aneurysmectomy (n = 2551), aortobifemoral bypass (n = 2616), lower extremity bypass (n = 6866), and major lower extremity amputation (n = 7442). The incidence of perioperative stroke was determined, and logistic regression analysis was used to identify independent risk factors for stroke. Logistic and linear regression analyses were used to quantify the effect of postoperative stroke on adjusted mortality and length of stay. Odds ratio (OR) and 95% confidence interval (CI) were defined. P <.05 was considered significant.

RESULTS

Stroke was uncommon after noncarotid vascular procedures, occurring in only 0.4% to 0.6% of patients. Independent risk factors for stroke include preoperative ventilation (OR, 11; 95% CI, 5.0-22.3; P <.001), previous stroke or transient ischemic attack (OR, 4.2; 95% CI, 2.7-6.4; P <.001), postoperative myocardial infarction (OR, 3.3; 95% CI, 1.3-8.7; P =.009), and need to return to the operating room (OR, 2.2; 95% CI, 1.4-3.5; P =.001). Factors that did not appear to be associated with stroke risk included procedure type, diabetes, renal failure, dialysis dependence, number of transfused units of blood, and hypertension. After controlling for other postoperative complications and comorbid conditions, postoperative stroke significantly increased the risk for perioperative mortality (OR, 6.3; 95% CI, 3.4-11.4; P <.001), with similar magnitude as postoperative myocardial infarction (OR, 6.3; 95% CI, 3.9-10.1; P <.001). Stroke was also associated with a 48% increase in overall length of stay.

CONCLUSIONS

Stroke after noncarotid peripheral vascular surgery is uncommon, but results in markedly increased mortality and length of stay. Stroke risk is most strongly associated with previous stroke history and greater degree of illness. Patients with these associated conditions deserve particular attention to assessing and medically managing modifiable risk factors.