Atul Mathur

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.

Comparison of aspirin alone versus aspirin plus ticlopidine after coronary artery stenting

This prospective nonrandomized study was performed comparing aspirin alone (n = 46) versus aspirin and ticlopidine (p = 338) following native coronary artery stenting. There were significantly more stent thrombosis events in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0.9%, p = 0.02) and significantly more Q-wave myocardial infarctions and cardiac-related deaths in the aspirin-only group than in the aspirin and ticlopidine group (6.5% vs 0%, p = 0.002 and 4.4% vs 0.3% p = 0.02, respectively).

Efficacy of coronary stenting in the management of cardiac allograft vasculopathy.

We undertook a study to determine the efficacy of stents in reducing restenosis in cardiac allograft vasculopathy. The result shows that coronary stenting significantly reduces restenosis in cardiac allograft vasculopathy compared with balloon angioplasty alone.

Elective Carotid Artery Stenting in the Presence of Contralateral Occlusion

Significant carotid stenosis in the presence of an occluded contralateral artery has a poor prognosis with medical therapy alone. Carotid cross clamping during surgical endarterectomy results in critical flow reductions in patients with inadequate collateral flow, and represents a significant risk for procedural strokes. Carotid stenting is being evaluated as an alternative to endarterectomy. We describe the immediate and late outcome of a series of 26 patients treated with carotid stenting in the presence of contralateral carotid occlusion. The mean age of the patients in this group was 65 +/- 9 years, 23 (89%) were men and 10 (39%) were symptomatic from the vessel treated. The procedural success of carotid stenting in this group of patients was 96%. The mean diameter stenosis was reduced from 76 +/- 15% to 2.8 +/- 5%. There was 1 (3.8%) minor stroke in a patient who developed air embolism during baseline angiography. At late follow-up there was no neurologic event in any patient at a mean of 16 +/- 9.5 months after the procedure. Thus, carotid stenting of lesions with contralateral occlusion can be performed successfully with a low incidence of procedural neurologic complications and late stroke.

Comparison of Balloon Angioplasty Versus Debulking Devices Versus Stenting in Right Coronary Ostial Lesions

Angioplasty of aorto-ostial stenosis is associated with lower procedural success and a higher complication rate. The aim of the present study was to compare the acute and long-term results of balloon and new device angioplasty in 110 consecutive patients with right coronary ostial lesions. Patients were divided into 3 groups according to the angioplasty device used: group I (balloon only, n = 26), group II (debulking devices including excimer laser, directional and rotational atherectomy, n = 26), group III (stent, n = 58). Procedural success was highest in group III (96%) followed by group I (88%), and group II (77%). In-hospital complications were similar among the groups (p = NS). Patients in group III achieved the highest acute gain (2.61 mm) followed by groups II (1.92 mm), and I (1.39 mm, p <0.05). During follow up, target lesion revascularization and/or bypass surgery was required in 24% of patients in group III compared with 47% and 40% in groups I and II, respectively (p <0.05). Cardiac-event free survival was highest in the stent group (74%, p <0.005) and was similar between the balloon (39%) and debulking device groups (45%). Thus, among the currently available technologies, stenting of right coronary ostial lesions appears to provide excellent angiographic and long-term results.

Relationship between oversizing of self-expanding stents and late loss index in carotid stenting

Stenting of the internal carotid artery is facilitated by stenting across the carotid bifurcation and sizing the diameter of a self-expanding stent to the large common carotid segment. This usually results in marked oversizing of the self-expanding stent in the internal carotid segment. This study was done to determine the relationship between stent oversizing and late luminal loss index after stenting of the internal carotid artery. Between September 1995 and March 1997, there were 165 patients (189 vessels) who underwent successful carotid stenting with self-expanding stents. Fifty-nine patients (63 vessels) had six-month follow-up carotid angiograms and on-line quantitative angiographic analysis. The mean reference diameter of the internal carotid arteries was 4.93+/-1.31 mm. Nominal stent size was 5 mm in 4 patients, 6 mm in 6 patients, 8 mm in 106 patients, 10 mm in 77 patients, and 12 mm in 1 patient. The average stent/patient was 1.03+/-0.16. There were three patients who had more than 50% diameter renarrowing at follow-up. The mean late loss index was 0.25+/-0.41. By linear regression analysis, there was no clear linear relationship between stent oversizing and late loss index after stenting (correlation coefficient = -0.21, P = 0.09). When analysis of variance with linear contrast was used to analyze six groups of different stent/artery ratios (from 1.4 to > or = 2), late loss indexes are significantly lower in the groups of high stent/artery ratio than the groups of low stent/artery ratio (P = 0.01). The process of oversizing of self-expanding stents deployed in the internal carotid artery does not appear to be associated with late restenosis and high stent/artery ratio seems to be associated with low late loss index.

Combined coronary and bilateral carotid stenting: A case report

We describe a patient who underwent stenting of both internal carotid arteries and two coronary arteries. Two combined carotid and coronary procedures were done 4 wk apart to revascularize the patient. The first procedure was complicated by a minor stroke with good recovery. At 6 mo of follow-up, he is asymptomatic and without angiographic restenosis.

Results of Elective Stenting of Branch-Ostial Lesions

Coronary stenting using both Palmaz-Schatz and Gianturco-Roubin stents for branch ostial lesions was performed in 48 patients with high success and low complication rates. The 6-month event-free survival rates were high in these patients.

Intracoronary stenting using slotted tubular stents without intravascular ultrasound and anticoagulation

Intravascular ultrasound guidance has been suggested as a prerequisite before managing patients receiving slotted tubular stents without anticoagulation. The purpose of this prospective observational study was to determine if patients receiving this stent can be similarly managed following angiographic guided stent deployment without intravascular ultrasound assistance. A total of 137 patients receiving slotted tubular stents were selected to receive a protocol of aspirin 325 mg and ticlopidine 250 mg for 30 days following the satisfaction of certain angiographic criteria. These criteria were: adequate coverage of intimal dissections, absence of residual filling defects, and normal (TIMI III) flow in the stented vessel at the end of the procedure. The stenting procedure was planned in 68% of patients and unplanned in 32% of patients. During the 30 day clinical follow period there were no stent thrombosis events, no Q-wave myocardial infarctions, and no deaths. Non-Q-wave myocardial infarction occurred in 3 patients (2.2%), hemorrhage requiring blood transfusion in 3 patients (2.2%), and 1 patient (0.7%) developed a pseudo-aneurysm of the cannulated femoral artery. These data indicate that patients receiving slotted tubular stents with optimal angiographic results can be safely managed with the combination of aspirin and ticlopidine without anticoagulation or the need for intravascular ultrasound guidance.

Does platelet glycoprotein IIb/IIIa receptor antibody improve in-hospital outcome of coronary stenting in high-risk thrombus containing lesions?

Coronary stenting in acute coronary syndromes probably increases the risk of acute stent thrombosis. Recently, use of platelet glycoprotein IIb/IIIa receptor antibody has been shown to improve percutaneous transluminal coronary angioplasty (PTCA) outcomes in high risk lesions. The purpose of this analysis was to determine safety and efficacy of platelet glycoprotein IIb/IIIa receptor antibody administration in patients receiving coronary stents in high‐risk lesions. Between October 1995 and November 1996, 282 patients with acute ischemic syndromes received coronary stents at our center: 73 had thrombus containing lesions—40 presented with AMI and 33 with unstable angina and make up the study population. The mean age of these patients was 61 ± 13 years, 56 were male, 35 had a history of myocardial infarctions (MI), 21 had prior coronary artery bypass graft (CABG), and 21 had prior PTCA. Coronary stenting was used for suboptimal result in 46 patients (63%), threatened closure in 25 patients (34%), and acute closure in 2 patients (3%). Platelet glycoprotein IIb/IIIa receptor antibody was administered during the procedure in 74% and after the procedure in 26%. A total of 115 stents were deployed (Gianturco‐Roubin 80, Palmaz‐Schatz 29, and Wallstent 6) in 24 LAD, 21 RCA, 15 LCX, and 13 saphenous vein graft (SVG) lesions. Procedural success was 100%. The mean diameter stenosis before and after intervention was 60% ± 31% and 4% ± 14%, respectively. In‐hospital events included 1 Q‐wave MI (1.4%), 13 non–Q‐wave MI (18%), and 1 death (1.4%). There was no subacute stent thrombosis, emergency CABG, or repeat PTCA. Significant in‐hospital bleeding complications were noted in seven (10%) patients, with five patients (6.8%) requiring blood transfusions. In this series of patients with acute ischemic syndromes associated with angiographic evidence of thrombus, combined use of platelet glycoprotein IIb/IIIa receptor antibody and stenting resulted in a very low incidence of subacute stent thrombosis and emergency target lesion revascularization. However, bleeding complications were higher than expected with conventional antiplatelet therapy following routine stenting. Cathet. Cardiovasc. Intervent. 46:415–420, 1999.