Biomedical subjects
Jay S Yadav
Publications and source records attributed to Jay S Yadav.
New insights into improving acute and long-term outcomes of carotid stenting.
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The role of antiplatelet therapy in carotid stenting for ischemic stroke prevention.
BACKGROUND AND PURPOSE: Carotid angioplasty and stenting (CAS) is a minimally invasive revascularization procedure that has become a popular and acceptable treatment option in the United States for high surgical risk patients with internal carotid artery atherosclerosis. It is effective and has an acceptable risk profile, but ischemic complications caused by distal embolization and underlying atherothrombosis persist. SUMMARY OF REVIEW: Atherothrombosis is the pathological process that is frequently implicated as the underlying cause of stroke, transient ischemic attacks, and most other ischemic vascular disease. Critical steps in the development of occlusive episodes are the disruption of atherosclerotic plaque and subsequent formation of a platelet-rich mural thrombus. Vascular injury as a result of CAS or any other percutaneous intervention triggers platelet adhesion, activation, and aggregation, resulting in the formation of a mural thrombosis. This risk, in addition to the potential risk of embolization to distal sites, provides a rationale for early antiplatelet therapy with CAS. The risk of late stent (>30 days after stenting) thrombosis in some patients, particularly those receiving drug-eluting stents, provides a rationale for prolonged antiplatelet prophylaxis as well as for prophylaxis against late atherothrombotic events. Because of the systemic and progressive nature of atherothrombosis, protection against ischemic vascular events in other arterial beds expands the benefits of long-term antiplatelet therapy. CONCLUSIONS: As clinical experience with CAS increases, it is likely that it will be used more frequently for patients with occlusive carotid disease. In addition, adjunct antiplatelet therapy will play a key role in the continued development of CAS.
Evaluating the optimal activated clotting time during carotid artery stenting.
Carotid artery stenting is an alternative to carotid endarterectomy for patients at high risk for surgery for carotid artery stenosis. Although unfractionated heparin is routinely used, there are no published data evaluating the optimal activated clotting time during carotid stenting. In a retrospective analysis of 605 patients who underwent carotid stenting using unfractionated heparin at the Cleveland Clinic Foundation, the optimal peak procedural activated clotting time associated with the lowest combined incidence of death, stroke, or myocardial infarction was 250 to 299 seconds.
Rate, predictors, and consequences of hemodynamic depression after carotid artery stenting.
OBJECTIVES: We sought to determine the frequency, predictors, and consequences of hemodynamic depression (HD) after carotid artery stenting (CAS). BACKGROUND: Hemodynamic depression has been reported after carotid artery stenting CAS and carotid endarterectomy (CEA). METHODS: We retrospectively analyzed data on 500 consecutive CAS procedures performed over a 5-year period. Hemodynamic depression was defined as periprocedural hypotension (systolic blood pressure <90 mm Hg) or bradycardia (heart rate <60 beats/s). Univariate and multivariate binary logistic regression models were used to determine the predictors and consequences of HD and persistent HD. RESULTS: The mean age of the patients was 70.5 +/- 10 years, and 69% were men. Hemodynamic depression occurred during 210 procedures (42%), whereas persistent HD developed in 84 procedures (17%). Features that independently predicted HD included lesions involving the carotid bulb (odds ratio [OR] 2.18 [range 1.46 to 3.26], p < 0.0001) or the presence of a calcified plaque (OR 1.89 [range 1.25 to 2.84], p < 0.002). Prior ipsilateral CEA was associated with reduced risk of HD (OR 0.35 [range 0.20 to 0.60], p < 0.0001). Patients who developed persistent HD were at a significantly increased risk of a periprocedural major adverse clinical event (OR 3.05 [range 1.35 to 5.23], p < 0.02) or stroke (OR 3.34 [range 1.13 to 9.90], p < 0.03). CONCLUSIONS: Hemodynamic depression is common after CAS, particularly in patients with a calcified plaque in the carotid bulb, but is easily treated with conventional methods. Patients who develop persistent HD are at an increased risk of periprocedural major adverse clinical events and stroke.
Intracranial angioplasty and stenting in the awake patient.
BACKGROUND AND PURPOSE: Endovascular treatment for intracranial atherosclerosis is evolving, but complications remain an issue. Most interventions are performed under general anesthesia, preventing intraprocedural clinical evaluations. We describe our approach to intracranial angioplasty and stenting, using local rather than general anesthesia, and intraprocedural neurological assessment. METHODS: We prospectively collected procedural and outcome information on all patients undergoing intracranial angioplasty and stenting. Patients underwent interventions under local anesthesia with mild intravenous sedation or analgesia only if needed. Intraoperative neurological evaluations were performed, and symptomatology was used to guide the interventional technique. RESULTS: Forty-eight arteries in 40 patients with a mean age of 65.2 years were treated. Thirty-two anterior and 16 posterior circulation segments were treated. Technical success was achieved in 100% of patients with reduction of the mean pretreatment stenosis from 85 +/- 8.6% to 7 +/- 10.1%. Stents were deployed in 40 segments; five patients were treated with drug-eluting stents. The cobalt-chromium coronary stents were the easiest to deliver. Thirty-seven patients were treated under local anesthesia and, of those, 61.4% experienced intraprocedural symptoms that led to some alteration of the interventional technique. Headache was the most common symptom, and, when persistent, it heralded the occurrence of subarachnoid hemorrhage. There were seven total neurological complications, but only five (10.5%) led to permanent morbidity (4 strokes) or mortality (1 death). CONCLUSIONS: Intracranial angioplasty and stenting can be successfully performed using coronary techniques and equipment including drug-eluting stents. Local anesthesia permits neurological evaluations and often leads to the adjustment of the interventional technique, potentially making the procedure safer.
Drug-eluting stents for the treatment of intracranial atherosclerosis: initial experience and midterm angiographic follow-up.
BACKGROUND AND PURPOSE: Intracranial stenting is associated with a 32% rate of restenosis. Drug-eluting stents (DES) have revolutionized the treatment of coronary artery disease and have greatly reduced the risk of in-stent stenosis. We present our experience with the feasibility and safety of using DES for patients with symptomatic intracranial atherosclerosis. METHODS: All of the patients had >70% stenoses and had failed maximal medical therapy. They were pretreated with aspirin, clopidogrel, and intraprocedural heparin. All of the lesions were predilated, and balloons and stents were slightly undersized. Clopidogrel and aspirin were continued for 1 year, and patients had clinical follow-up and vascular imaging at 30 days, 6 months, and 1 year. RESULTS: Eight patients with intracranial internal carotid artery (3), middle cerebral (2), basilar (2), and vertebral artery (1) stenoses were successfully treated with 4 Cypher (Cordis Corp) and 4 Taxus (Boston Scientific Inc) stents. The mean stenosis severity was reduced from 84.4%+/-10.2% to 2.5%+/-4.6%. One patient had an intraprocedural retinal embolism, but there were no other complications. Over a mean follow-up of 11.1+/-4.9 months (range, 2 to 17.3 months), patients have had repeat angiography (5) or transcranial Doppler with or without CT angiography (3). None of the patients have had clinical or significant angiographic restenosis or required target vessel revascularization. CONCLUSIONS: Elective intracranial stenting with DES appears to be feasible and safe, but additional clinical experience is required to assess its efficacy.
Impact of body mass index on outcome in patients undergoing carotid stenting.
The outcomes of patients who underwent carotid artery interventions were evaluated by body mass index (BMI). Although there was no association between BMI and short-term outcomes, patients with small BMIs were susceptible to an exaggerated long-term mortality hazard.
Slow-flow phenomenon during carotid artery intervention with embolic protection devices: predictors and clinical outcome.
OBJECTIVES: The purpose of this research was to define the predictors of the "slow-reflow" phenomenon during carotid artery intervention with filter-type embolic protection devices (EPDs) and to determine its prognostic significance. BACKGROUND: During carotid artery intervention using filter-type EPDs, we have observed cases in which there is angiographic evidence of a significant reduction in antegrade flow in the internal carotid artery proximal to the filter device, termed "slow-flow." The predictors of this phenomenon and its prognostic significance are unknown. METHODS: Using a single-center prospective carotid intervention registry, patients with slow-flow were compared to patients with normal flow during carotid intervention with respect to clinical, procedural, and lesion characteristics, and the 30-day incidence of death and stroke. RESULTS: A total of 414 patients underwent 453 carotid artery interventions using EPDs. Slow-flow occurred in 42 patients (10.1%) undergoing 42 carotid interventions (9.3%), and most commonly occurred after post-stent balloon dilatation (71.4%). Multivariate logistic regression analysis identified the following predictors of slow-flow: recent history (<6 months) of stroke or transient ischemic attack (odds ratio [OR] 2.8, 95% confidence interval [CI] 1.4 to 5.6, p = 0.004), increased stent diameter (OR 1.4, 95% CI 1.02 to 1.94, p = 0.044), and increased patient age (OR 1.05, 95% CI 1.01 to 1.09, p = 0.025). Among patients with slow-flow, the 30-day incidence of stroke or death was 9.5% compared to 2.9% in patients with normal flow (chi-square = 4.73, p = 0.03). This difference was driven by the disparity in the 30-day incidence of stroke (9.5% vs. 1.7%). CONCLUSIONS: Slow-flow during carotid intervention with EPDs is a frequent event that is associated with an excess risk of periprocedural stroke. The association of the phenomenon with clinically symptomatic carotid lesions and use of larger stent diameters suggests that embolization of vulnerable plaque elements may play a pathogenic role.
Multimodal therapy for the treatment of severe ischemic stroke combining GPIIb/IIIa antagonists and angioplasty after failure of thrombolysis.
BACKGROUND AND PURPOSE: Intraarterial and intravenous thrombolysis are often ineffective for the treatment of acute ischemic stroke and are associated with a significant risk of intracranial hemorrhage (ICH). Multimodal rescue therapy combining mechanical disruption and platelet GPIIb/IIIa receptor antagonists may improve recanalization. METHODS: Patients who did not recanalize with thrombolysis were treated with GPIIb/IIIa antagonists, angioplasty, or an embolectomy device. Treatment was individualized based on vascular anatomy, stroke mechanism, patient status, and symptom duration. RESULTS: Twelve patients were treated within 3.8+/-2.2 hours. The mean National Institutes of Health Stroke Scale (NIHSS) score was 19.4+/-4.1. Six patients had carotid terminus occlusion, whereas 5 had middle cerebral artery and 1 had basilar artery occlusion. The average doses of intraarterial tPA and reteplase were 17.1+/-8.6 mg and 2+/-0.6 units, respectively. All patients received either an intravenous or intraarterial abciximab bolus (mean 11.8+/-5.8 mg) and heparin (mean 3278+/-1716U). Eleven were treated with angioplasty and 4 had mechanical embolectomy or stenting. Complete (8) or partial (3) recanalization was achieved in 11 cases. There was only one (8.3%) symptomatic hemorrhage. Patients had a favorable outcome at discharge (mean NIHSS 8.9+/-8.7) and 6 (50%) had an NIHSS < or =4 at discharge. CONCLUSIONS: Multimodal rescue therapy was effective at recanalizing occluded cerebral vessels that failed thrombolysis without an excess risk of ICH.
Comparison of results of carotid stenting followed by open heart surgery versus combined carotid endarterectomy and open heart surgery (coronary bypass with or without another procedure).
We compared a novel strategy of carotid stenting (CS) followed by open heart surgery (OHS) to the combined carotid endarterectomy (CEA) and the OHS approach in patients requiring coronary and carotid revascularization. Between 1997 and 2002, CS as a prelude to OHS was performed in 56 patients, and 111 patients underwent combined CEA+OHS. Adverse events included stroke, myocardial infarction (MI), death, and their combinations. At baseline, the CS+OHS group had more unstable/severe angina (52% vs 27%, p = 0.002), severe left ventricular dysfunction (20% vs 9%, p = 0.05), symptomatic carotid disease (46% vs 23%, p = 0.002), and the need for repeat OHS (32% vs 9%, p = 0.0002). Severe contralateral carotid disease was more prevalent in the CEA+OHS group (28% vs 11%, p = 0.01). At 30 days, CS+OHS patients had a significantly lower incidence of stroke or MI (5% vs 19%, p = 0.02). A propensity score was created for each patient to account for baseline differences. In a final logistic regression model that included the propensity score, CS+OHS was associated with a trend toward reduced stroke or MI (odds ratio 0.26, 95% confidence interval 0.06 to 1.09, p = 0.06) and reduced death, stroke, or MI (odds ratio 0.40, 95% confidence interval 0.12 to 1.27, p = 0.12). In conclusion, despite a higher baseline risk profile, patients who underwent CS+OHS had significantly fewer adverse events than those undergoing CEA+OHS. CS may be a safer carotid revascularization option for this challenging patient population.
Leukocyte count predicts microembolic Doppler signals during carotid stenting: a link between inflammation and embolization.
BACKGROUND AND PURPOSE: Protected stenting has emerged as a safe and effective alternative to endarterectomy for the treatment of carotid stenosis in patients at high operative risk. Distal microembolization occurs invariably during carotid stenting. Little is known about the relationship between systemic inflammation and embolization during carotid stenting. METHODS: We examined 43 consecutive patients who underwent carotid stenting with simultaneous transcranial Doppler (TCD) monitoring of the ipsilateral middle cerebral artery. Embolization was quantified by measuring microembolic signals (MES) on TCD. Preprocedure leukocyte counts were related to MES. RESULTS: In unadjusted analyses, preprocedure leukocyte count was positively correlated with total procedural MES (r2= 0.16; P=0.008). After considering age, gender, comorbidities, concomitant medical therapies, and the use of emboli prevention devices, increasing leukocyte count (beta=35 for each 1000/microL increment; P=0.018) remained a significant and independent predictor of embolization (model-adjusted r2=0.365; P=0.0005). CONCLUSIONS: Increasing preprocedure leukocyte count independently predicted more frequent MES during carotid stenting. These data suggest that systemic inflammation may influence the degree of procedural embolization.
Effectiveness and safety of bivalirudin during percutaneous coronary intervention in a single medical center.
A recent large-scale, randomized trial demonstrated the noninferiority of a strategy of bivalirudin with provisional glycoprotein (GP) IIb/IIIa inhibition compared with routine GP IIb/IIIa inhibition. There is a paucity of outcome data with bivalirudin use in the setting of real-world experience. We evaluated 6,996 patients who underwent percutaneous coronary intervention between January 2001 and December 2004 to compare early and late outcomes with a bivalirudin-based antithrombotic regimen with those with a heparin-based regimen. Propensity adjustment was performed to correct for baseline differences in patient characteristics. Bivalirudin-based therapy was used in 1,070 patients, heparin only in 801 patients, and heparin plus GP IIb/IIIa inhibitors in 5,125 patients. Compared with patients who received heparin or those who received heparin plus GP IIb/IIIa inhibitors, patients who received bivalirudin had lower incidences of bleeding (blood transfusion rate 1.7% vs 4.0%, p <0.001) and periprocedural myonecrosis (creatine kinase-MB >5 times the upper limit of normal 2.7% vs 4.3%, p = 0.016). Differences in bleeding end points remained significant after adjusting for the propensity to receive bivalirudin, but there was no difference in ischemic events. There was no difference in unadjusted long-term survival rate (log-rank test p = 0.46, total number of deaths 412, mean follow-up 17 months) or in propensity-adjusted long-term survival rate (hazard ratio 1.37, 95% confidence interval 0.90 to 2.08, p = 0.14). Compared with heparin with or without GP IIb/IIIa inhibition, the use of bivalirudin in a large consecutive patient registry at a tertiary care center was associated with fewer bleeding events and no evident increase in the incidence of ischemic complications.
Comparison of the safety and efficacy of emboli prevention devices versus platelet glycoprotein IIb/IIIa inhibition during carotid stenting.
Distal embolization is the main potential risk of carotid stenting, and techniques to minimize this risk are evolving. Between July 1998 and March 2002, 305 consecutive patients who underwent elective or urgent percutaneous carotid intervention at The Cleveland Clinic were prospectively followed. During this period, the clinical practice of carotid stenting evolved from the routine use of glycoprotein IIb/IIIa inhibitors (GPIs) to routine emboli-prevention device (EPD) placement. A total of 199 patients received adjunctive GPIs (91% abciximab), and 106 patients underwent the procedure with an EPD (85% filter design, 15% occlusive balloon). At 30 days, the composite end point of neurologic death, nonfatal stroke, and major bleeding, including intracranial hemorrhage, was significantly lower among patients treated with EPDs compared with those treated with GPIs (0% vs 5.1%, p = 0.02). EPDs may provide an overall safer and more effective means of neuroprotection during carotid stenting than GPIs.
New frontiers in interventional cardiology.
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Symptomatic patients have similar outcomes compared with asymptomatic patients after carotid artery stenting with emboli protection.
In a single-center cohort of 174 consecutive patients, we sought to evaluate whether the use of emboli protection devices (EPDs) results in equivalent rates of adverse events in symptomatic and asymptomatic patients after carotid artery stenting (CAS) with EPDs. Death or stroke occurred in 3.3% in the symptomatic group and in 3.5% of the asymptomatic group at 30 days (p = NS). At 6 months, there was also no significant difference in the rate of stroke or death between the groups. Unlike surgical revascularization, symptomatic patients did not have a greater risk for stroke and death compared with asymptomatic patients after CAS with EPDs.
Endovascular management of spontaneous carotid artery dissection.
OBJECTIVE: Despite medical therapy, a subset of patients with spontaneous carotid artery dissection (SCD) experience recurrent or progressive symptoms. In this study, we assessed the safety and efficacy of endovascular stent angioplasty in the treatment of SCD. METHODS: Seven consecutive patients with SCD underwent endovascular stent angioplasty of a total of 12 vessels. Indications included the presence of a large or enlarging pseudoaneurysm, a contraindication to anticoagulation, failure of anticoagulation, and compromised cerebral blood flow. RESULTS: Five patients had fibromuscular dysplasia. All patients tolerated the procedure well, with no adverse clinical events. All patients showed symptomatic improvement on clinical follow-up except for one patient, who had hemorrhagic conversion of a pre-existing large ischemic stroke 13 days after intervention; he made an eventual recovery to baseline. All stents have remained patent on radiologic follow-up. CONCLUSIONS: This study provides additional evidence that endovascular stent angioplasty is a safe and effective treatment for SCD in patients for whom medical treatment is not adequate.
Feasibility trial of carotid stenting with and without an embolus protection device.
PURPOSE: To evaluate the feasibility of stenting and cerebral protection in patients with carotid bifurcation disease. METHODS: Carotid stenting with self-expanding nitinol stents was evaluated in 261 patients (157 men; mean age 70.9+/-9.7 years, range 41-90) treated at 33 clinical sites. Among these patients, 141 (54.3%) were symptomatic, and 71 (27.2%) had postendarterectomy restenotic lesions. An embolus protection device became available in the latter third of the study. The primary endpoint of the study was the 30-day composite occurrence of major adverse clinical events (all deaths, strokes, or myocardial infarctions [MI]). At 1 year, the endpoint included all deaths, strokes, or MIs at 30 days, plus all deaths or ipsilateral strokes between 31 days and 1 year. RESULTS: SMART stents were placed in 147 (56%) patients and Precise stents in 107 (41%); 7 (3%) patients were treated with non-study stents. Lesion success, defined as <30% postprocedural residual stenosis, was achieved in 249 (95%). An AngioGuard filter was used in 85 patients; of 90 filters employed, 78 (87%) were successfully deployed and retrieved. Visible material was noted in 42 (54%) retrieved filters. One (0.4%) stent thrombosis occurred at <30 days, and no restenotic lesions >80% were noted in up to 1 year of follow-up. At 30 days, stroke occurred in 16 (6.1%) patients, MI in 1 (0.4%), and 2 (0.8%) patients died. The 30-day rate of stroke, MI, or death was 6.9%. Major ipsilateral stroke occurred in 4 (1.5%) patients between 0 and 30 days; no new major ipsilateral strokes were noted up to 1 year. By Kaplan-Meier analysis, the 1-year risk of stroke, MI, or death was 10.9%+/-2.0%. The 1-year risk of major ipsilateral stroke was significantly lower in patients treated with embolus protection devices (0.0% versus 2.3%, p=0.05). CONCLUSIONS: The use of nitinol self-expanding stents in the carotid position appears to be a safe and efficacious alternative for the treatment of carotid bifurcation disease. The addition of embolus protection devices may diminish the risk of postprocedural major ipsilateral strokes.