Jay S. Yadav

Recognition of the Importance of Embolization in Atherosclerotic Vascular Disease

It is uncommon in medicine for emerging data to completely transform a field, particularly in such a common disease state as atherosclerotic vascular disease. New evidence from multiple fronts has underscored the frequency and prognostic importance of atherosclerotic embolization in the microvasculature. Until recently, we have had limited access to diagnose microvascular obstruction in living patients. With the availability of imaging technology that includes magnetic resonance, myocardial contrast echocardiography, and transcerebral or transcranial Doppler (TCD), microvascular obstruction has been documented in a far greater proportion of patients than ever conceived. The linkage between microvascular obstruction and unfavorable long-term clinical prognosis has been established in many series. Furthermore, therapeutics shown to reduce microvascular obstruction have improved clinical outcomes. The purpose of this article is to present the case for a disturbingly and unexpectedly high rate of arterial embolization in certain atherosclerotic conditions and to review the promise of newer therapeutics or devices to reduce the risk or ameliorate the sequelae of embolization. Acute myocardial infarction (MI) has been accepted to be related primarily to a fissured, eroded, or ruptured plaque.1 2 3 4 5 This event leads to exposure of subendothelial matrix, with attendant platelet aggregation, thrombus, and occlusion of a major epicardial vessel. In a continuum, unstable angina and non–ST-segment-elevation MI also are indexed to a breech of the arterial wall, but the resultant thrombus is usually mural, not occlusive. Embolization of plaque contents of platelet-thrombus into the microvasculature has been reported in some patients with these acute coronary syndromes, but it has been generally believed to be uncommon.1 2 6 7 In some cases of sudden death, the process of embolization has been speculated to play an important role. It is nevertheless surprising that systematic pathological studies of the microvasculature of the postmortem heart infarct territory have …

Elective Stenting of the Extracranial Carotid Arteries

OBJECTIVES In symptomatic and asymptomatic patients with significant carotid artery stenosis, surgical endarterectomy has been shown to be beneficial when compared with medical management. Carotid stenting is evolving as an alternative technique for treating such patients. This prospective study was designed to assess the feasibility and safety of carotid angioplasty and stenting. METHODS Fourteen patients (15 carotid arteries) with significant carotid artery stenosis were enrolled. These patients were in the age range 46 to 84 years (mean 60.9 +/- 7 years) and there were 12 males (86%). All of these patients were symptomatic with either TIA (n = 8) or stroke (n = 6). Wallstents were used in all the cases to stent the carotid arteries. One patient underwent bilateral carotid artery stenting. RESULTS Carotid angioplasty and stenting was successful in 13 out of 14 (92.8%) patients and 14 out of 15 (93.3%) carotid arteries, with reduction in mean (+/- SD) stenosis from 86 +/- 6% to 3 +/- 3%. There was one episode of minor stroke, no major stroke or death during the initial hospitalization. Another patient had a minor stroke with patent ipsilateral carotid artery (on repeat angiography) during the first 30 days after the procedure. This patient was also found to have asymptomatic thrombus formation in the contralateral carotid stent which resolved with intravenous anticoagulation. During a mean follow up of 6 +/- 2 months there has been no recurrence of symptoms. CONCLUSIONS Based upon our limited experience we believe that percutaneous carotid angioplasty with stenting is feasible with low periprocedural complication rate.

Wireless pulmonary artery haemodynamic monitoring in chronic heart failure: a randomised controlled trial

BACKGROUND Results of previous studies support the hypothesis that implantable haemodynamic monitoring systems might reduce rates of hospitalisation in patients with heart failure. We undertook a single-blind trial to assess this approach. METHODS Patients with New York Heart Association (NYHA) class III heart failure, irrespective of the left ventricular ejection fraction, and a previous hospital admission for heart failure were enrolled in 64 centres in the USA. They were randomly assigned by use of a centralised electronic system to management with a wireless implantable haemodynamic monitoring (W-IHM) system (treatment group) or to a control group for at least 6 months. Only patients were masked to their assignment group. In the treatment group, clinicians used daily measurement of pulmonary artery pressures in addition to standard of care versus standard of care alone in the control group. The primary efficacy endpoint was the rate of heart-failure-related hospitalisations at 6 months. The safety endpoints assessed at 6 months were freedom from device-related or system-related complications (DSRC) and freedom from pressure-sensor failures. All analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00531661. FINDINGS In 6 months, 83 heart-failure-related hospitalisations were reported in the treatment group (n=270) compared with 120 in the control group (n=280; rate 0·31 vs 0·44, hazard ratio [HR] 0·70, 95% CI 0·60-0·84, p<0·0001). During the entire follow-up (mean 15 months [SD 7]), the treatment group had a 39% reduction in heart-failure-related hospitalisation compared with the control group (153 vs 253, HR 0·64, 95% CI 0·55-0·75; p<0·0001). Eight patients had DSRC and overall freedom from DSRC was 98·6% (97·3-99·4) compared with a prespecified performance criterion of 80% (p<0·0001); and overall freedom from pressure-sensor failures was 100% (99·3-100·0). INTERPRETATION Our results are consistent with, and extend, previous findings by definitively showing a significant and large reduction in hospitalisation for patients with NYHA class III heart failure who were managed with a wireless implantable haemodynamic monitoring system. The addition of information about pulmonary artery pressure to clinical signs and symptoms allows for improved heart failure management. FUNDING CardioMEMS.

Long-Term Results of Carotid Stenting versus Endarterectomy in High-Risk Patients

BACKGROUND We previously reported that, in a randomized trial, carotid stenting with the use of an emboli-protection device is not inferior to carotid endarterectomy for the treatment of carotid artery disease at 30 days and at 1 year. We now report the 3-year results. METHODS The trial evaluated carotid artery stenting with the use of an emboli-protection device as compared with endarterectomy in 334 patients at increased risk for complications from endarterectomy who had either a symptomatic carotid artery stenosis of at least 50% of the luminal diameter or an asymptomatic stenosis of at least 80%. The prespecified major secondary end point at 3 years was a composite of death, stroke, or myocardial infarction within 30 days after the procedure or death or ipsilateral stroke between 31 days and 1080 days (3 years). RESULTS At 3 years, data were available for 260 patients (77.8%), including 85.6% of patients in the stenting group and 70.1% of those in the endarterectomy group. The prespecified major secondary end point occurred in 41 patients in the stenting group (cumulative incidence, 24.6%; Kaplan-Meier estimate, 26.2%) and 45 patients in the endarterectomy group (cumulative incidence, 26.9%; Kaplan-Meier estimate, 30.3%) (absolute difference in cumulative incidence for the stenting group, -2.3%; 95% confidence interval, -11.8 to 7.0). There were 15 strokes in each of the two groups, of which 11 in the stenting group and 9 in the endarterectomy group were ipsilateral. CONCLUSIONS In our trial of patients with severe carotid artery stenosis and increased surgical risk, no significant difference could be shown in long-term outcomes between patients who underwent carotid artery stenting with an emboli-protection device and those who underwent endarterectomy. (ClinicalTrials.gov number, NCT00231270 [ClinicalTrials.gov].).

Immediate and Late Clinical Outcomes of Carotid Artery Stenting in Patients With Symptomatic and Asymptomatic Carotid Artery Stenosis

Background—Carotid stenting is a less invasive percutaneous procedure than carotid endarterectomy for the treatment of carotid stenosis. Reports suggest that it can be performed with periprocedural complication rates similar to those of carotid endarterectomy. The purpose of this study was to determine short- and long-term outcomes in the largest prospective cohort of carotid stenting patients. Methods and Results—This study followed 528 consecutive patients (604 hemispheres/arteries) undergoing carotid stenting. There was a 0.6% (n=3) fatal stroke rate and 1% (n=5) nonstroke death rate at 30 days. The major stroke rate was 1% (n=6), and the minor stroke rate was 4.8% (n=29). The overall 30-day stroke and death rate was 7.4% (n=43). Over the 5-year study period, the 30-day minor stroke rate improved from 7.1% (n=7) for the first year to 3.1% (n=5) for the fifth year (P<0.05 for trend). The best predictor of 30-day stroke and death was age ≥80 years. After the 30-day period, the incidence of fatal and nonf...

Global experience in cervical carotid artery stent placement

The purpose of this article is to review and update the current status of carotid artery stent placement in the world. Surveys to major interventional centers in Europe, North and South America, and Asia were initially completed in June 1997. Subsequent information from these 24 centers in addition to 12 new centers has been obtained to update the information. The survey asked the various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 5,210 procedures involving 4,757 patients. There was a technical success of 98.4% with 5,129 carotid arteries treated. Complications that occurred during the carotid stent placement or within a 30‐day period following placement were recorded. Overall, there were 134 transient ischemic attacks (TIAs) for a rate of 2.82%. Based on the total patient population, there were 129 minor strokes with a rate of occurrence of 2.72%. The total number of major strokes was 71 for a rate of 1.49%. There were 41 deaths within a 30‐day postprocedure period resulting in a mortality rate of 0.86%. The combined minor and major strokes and procedure‐related death rate was 5.07%. Restenosis rates of carotid stenting have been 1.99% and 3.46% at 6 and 12 months, respectively. The rate of neurologic events after stent placement has been 1.42% at 6–12‐month follow‐up. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative for vascular surgery, especially for patients that are high risk for standard carotid endarterectomy. The periprocedure risks for major and minor strokes and death are generally acceptable at this early stage of development and have not changed significantly since the first survey results. Cathet. Cardiovasc. Intervent. 50:160–167, 2000. ©2000 Wiley–Liss,Inc.

Predictors of Stroke Complicating Carotid Artery Stenting

BACKGROUND The evolving technique of carotid stenting is being evaluated as an alternative to endarterectomy. Identification of the factors that predispose a patient to neurological complications would facilitate further refinement of the technique and optimize patient selection. METHODS AND RESULTS We analyzed the impact of various clinical, morphological, and procedural determinants on the development of procedural strokes in 231 patients who underwent elective (primary) stenting of 271 extracranial carotid arteries. The mean age of the patients was 68.7+/-10 years, 165 (71%) were males, and 139 (60%) had symptoms attributed to the lesion treated. This series represented a high-risk subset with 164 patients (71%) having significant coronary artery disease, 91 (39%) having bilateral disease, and 28 (12%) having contralateral carotid occlusion. Of the treated vessels, 59 (22%) had prior carotid endarterectomy, 66 (24%) had ulcerated plaques, and 87 (32%) had calcified lesions. Only 37 treated vessels (14%) would have been eligible for inclusion in the North American Symptomatic Carotid Endarterectomy Trial (NASCET). There were 17 (6.2%) minor and 2 (0.7%) major strokes during and within 30 days of the procedure. NASCET-eligible patients had a low (2.7%) risk of procedural strokes after carotid stenting. The results of multivariate analysis revealed advanced age (P=.006) and presence of long or multiple stenoses (P=.006) as independent predictors of procedural strokes. CONCLUSIONS During this procedural developmental phase of carotid stenting, neurological complications were highly dependent on patient selection. Advanced age and long or multiple stenoses were independent predictors of procedural stroke.

Current global status of carotid artery stent placement.

Our purpose was to review the current status of carotid artery stent placement throughout the world. Surveys were sent to major interventional centers in Europe, North and South America, and Asia. Information from peer-reviewed journals was also included and supplemented the survey. The survey asked various questions regarding the patients enrolled, procedure techniques, and results of carotid stenting, including complications and restenosis. Of the centers which were sent surveys, 24 responded. The total number of endovascular carotid stent procedures that have been performed worldwide to date included 2,048 cases, with a technical success of 98.6%. Complications that occurred during carotid stent placement or within a 30-day period following placement were recorded. Overall, there were 63 minor strokes, with a rate of occurrence of 3.08%. The total number of major strokes was 27, for a rate of 1.32%. There were 28 deaths within a 30-day postprocedure period, resulting in a mortality rate of 1.37%. Restenosis rates of carotid stenting have been 4.80% at 6 mo. Endovascular stent treatment of carotid artery atherosclerotic disease is growing as an alternative to vascular surgery, especially for patients that are at high risk for standard carotid endarterectomy. The periprocedural risks for major and minor strokes and death are generally acceptable at this early stage of development.

Angioplasty and Stenting for Restenosis After Carotid Endarterectomy Initial Experience

BACKGROUND AND PURPOSE Endarterectomy for recurrent carotid stenosis after endarterectomy has a significantly higher complication rate than the original operation. Angioplasty and stenting may offer a useful alternative treatment for these patients. METHODS Between September 1994 and April 1996, 22 patients had 25 carotid arteries treated with angioplasty and stenting for postendarterectomy restenosis. All patients had an independent neurological examination and National Institutes of Health Stroke Scale evaluation before and after the procedure. Patients were treated with aspirin and ticlopidine. All patients were requested to return at 6 months for follow-up angiography. The mean patient age was 69 +/- 7 years, and the mean elapsed time from endarterectomy was 73 +/- 69 months. Seventy-seven percent of the patients were symptomatic. RESULTS Mean stenosis was reduced from 79 +/- 13% before the procedure to 1.8 +/- 3.6% after stenting. One patient had a minor stroke, for a complication rate of 4% per treated artery. In the eight patients who returned for 6-month angiography, mean stenosis was 19.4 +/- 4.4% and restenosis (> or = 50% stenosis) did not occur. CONCLUSIONS In a small series, angioplasty and stenting appear to be safe and well tolerated for the treatment of postendarterectomy restenosis.

The CAPTURE registry: Results of carotid stenting with embolic protection in the post approval setting

Background: Pivotal study data examining carotid stenting with embolic protection as a less invasive alternative to endarterectomy for high surgical risk patients have been acquired under controlled conditions with highly selected physicians and hospitals. This report examines outcomes of carotid stenting post‐approval after diffusion of this technology to a broader cross‐section of physicians and hospitals. Methods: The Carotid Acculink/Accunet Post‐Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi‐center registry to assess two important aspects of the post‐IDE experience: the safety of carotid stenting by physicians with varying levels of experience as a measure of the adequacy of physician training, and the identification of rare/unexpected device‐related complications. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30 days post‐procedure. Results: 3,500 patients were enrolled by 353 physicians at 144 sites. The 30‐day primary endpoint event rate was 6.3% (95% CI: 5.5–7.1%) and did not differ among the three operator experience levels (5.3%, 6.0%, and 7.4%; P = 0.31) from most to least experienced, respectively. There were no differences in outcomes among physician specialties when adjusted for case mix. There were no unanticipated device related adverse events. Conclusions: The results of the CAPTURE study compare favorably to those achieved in the predicate pivotal investigations, and suggest that the post‐approval transfer of this new therapy to the community practice setting via carotid stent training programs is effective in preparing physicians with varying experience levels and specialty training backgrounds.