Ramazanali Ahmadi

Pro-CAS: A Prospective Registry of Carotid Angioplasty and Stenting

Background and Purpose— The German Societies of Angiology and Radiology have instituted a prospective registry of carotid angioplasty and stenting (CAS) to limit uncontrolled use of CAS and to collect data about technique and results of CAS outside clinical trials. Methods— A total of 38 centers register their patients prospectively before CAS is performed. At discharge, technical details, periprocedural medication, and the clinical course are reported on a standardized form. Results— During the first 48 months, 3853 planned interventions were recorded, and CAS was actually attempted on 3267 patients of whom 1827 (56%) were symptomatic and 1433 (44%) were asymptomatic. In 3127 (98%) cases, stents were used, of which 2784 (89%) were of the self-expanding type. Other technical aspects such as the use of guiding catheters and protection devices varied widely among the centers. Periprocedural medication rather uniformly included aspirin and clopidogrel before and after CAS and high-dose heparin and atropin during CAS. CAS was successful in 3207 (98%) cases. There was a 0.6% (n=18) mortality rate, a 1.2% (n=38) major stroke rate, and a 1.3% (n=41) minor stroke rate. The combined stroke and death rate was 2.8% (n=90). Conclusions— These prospective multicenter data are likely to give a realistic picture of the possibilities and limitations of CAS in the general community. They suggest that CAS may be performed with similar results in the general community as they have been reported by highly specialized centers and in clinical studies.

Carotid artery stenting: effect of learning curve and intermediate-term morphological outcome.

Purpose: To assess the impact of learning on the rate of success and complications of carotid stenting in a single-center, one-operator series and prospectively follow a patient cohort with regard to restenosis. Methods: In 303 patients (mean age 70 ± 8.8 years), 320 internal carotid arteries (ICA) were treated with carotid stenting for stenoses ≥70%. Four groups of 80 consecutive interventions were compared with regard to primary technical success and periprocedural complications. Stent patency in follow-up was assessed using duplex scanning. Results: Stenting was successful in 298 (93%) arteries. The combined neurological complications (transient ischemic attacks and all strokes) and 30-day death rate was 8.2% (n = 25), but the all stroke and 30-day death rate was 3.0% (n = 9). A significant reduction in the frequency of neurological complications after the initial 80 interventions was observed (p = 0.03), but technical success was not appreciably improved with increasing experience thereafter. Over a median 12 months (interquartile range 6 to 24), cumulative patency rates were 91%, 90%, and 91% at 6, 12, and 36 months, respectively. Conclusions: Elective carotid stenting can be performed with excellent technical success, an acceptable frequency of periprocedural complications, and good intermediate-term patency. However, our findings suggest that a larger number of interventions should be performed to overcome the negative effects of the initial learning phase.

Value of color duplex sonography for evaluation of tibioperoneal arteries in patients with femoropopliteal obstruction: A prospective comparison with anterograde intraarterial digital subtraction angiography

PURPOSE This study investigated the accuracy of color duplex sonography (CDS) compared with anterograde intraarterial digital subtraction angiography in the evaluation of the tibioperoneal arteries in patients with peripheral arterial occlusive disease. METHODS Fifty consecutive patients with femoropopliteal obstruction were examined immediately before planned percutaneous transluminal angioplasty. All CDS examinations were performed by one observer; the angiograms were interpreted independently by two readers (A1, A2). We compared agreement concerning judgement of the dominant crural artery (suitable for an eventual femorocrural bypass operation) and judgement of the severity of arterial lesions. RESULTS Concerning judgement of the dominant artery, the interobserver agreement between the two readers of the angiograms was better (kappa value, 0.76) than the agreement between CDS versus A1 (0.61) and CDS versus A2 (0.56). However, the differences were not statistically significant. The results were independent (no significant differences in the kappa values) of the following criteria: presence of diabetes; clinical stage of peripheral arterial occlusive disease; kind of femoropopliteal obstruction; and status of the popliteal artery. Concerning the evaluation of the severity of arterial lesions, the kappa values were significantly higher (p < 0.05) for A1 versus A2 (posterior tibial, 0.87; anterior tibial, 0.79; peroneal, 0.52) than for CDS versus A1 (0.51; 0.46; 0.07) and CDS versus A2 (0.35; 0.38; -0.05). The sensitivity of CDS (vs A1 as reference) for detecting a hemodynamically relevant arterial lesion (stenosis or occlusion) was 100% in the posterior tibial artery, 78% in the anterior tibial artery, and 92% in the peroneal artery. CONCLUSION Compared with intraarterial anterograde digital subtraction angiography, the value of CDS-with its currently used technology-for evaluation of the dominant lower leg artery suitable for an eventual femorocrural bypass operation in patients who have femoropopliteal obstruction is limited. It cannot replace an accurate preoperative angiogram for the routine clinical practice, and its use should be restricted to special cases (such as patients with a history of severe allergic reaction to contrast media or of severely impaired kidney function). CDS is also limited in the accurate judgement of the morphologic features of the runoff arteries in their full length in patients with peripheral arterial occlusive disease.

Hypotension and bradycardia after elective carotid stenting: frequency and risk factors.

Purpose: To investigate the frequency of and risk factors for hypotension and bradycardia in response to elective carotid stenting and their association with neurological complications. Methods: A retrospective analysis was conducted of 471 patients (321 men; median age 72 years, interquartile range 64–77) who underwent elective carotid artery stenting without cerebral protection for high-grade (>70%) symptomatic (n = 147) or asymptomatic (n=324) internal carotid artery stenosis at a single center. Frequency and potential risk factors for severe hypotension (systolic blood pressure <80 mmHg) or bradycardia (heart rate <50 bpm) were studied. Results: Thirty-four (7%) patients had severe hypotension (n=23), bradycardia (n=2), or both (n=9) despite routine premedication with atropine and adequate fluid balance. Intravenous catecholamines (dopamine) were necessary in 8 patients with prolonged hypotension; none of the patients with bradycardia needed pacemaker support. Neurological complications (transient ischemic attack, minor stroke, major stroke, death) occurring in 33 (7%) patients were not significantly associated with hemodynamic instability (4/34 [12%] versus 29/437 [7%], p = 0.26). Age >77 years (fourth quartile; OR 6.40, 95% CI 1.80 to 22.78, p=0.004) and coronary artery disease (OR 2.81, 95% CI 1.29 to 6.14, p=0.010) were associated with an increased adjusted risk for hypotension or bradycardia. Conclusions: Hemodynamic instability due to hypotension and bradycardia in response to carotid artery stenting occurs in a relatively low proportion of patients. Elderly patients and those with coronary artery disease are at highest risk. Although the rate of neurological complications was not significantly increased in patients with hemodynamic instability, the higher frequencies of neurological complications in these patients admonish us to be careful.

Risk Stratification for Subclavian Artery Angioplasty: Is There an Increased Rate of Restenosis after Stent Implantation?

Purpose:To compare long-term patency after balloon angioplasty of stenotic or occluded subclavian arteries with and without adjunctive stenting and to identify independent risk factors for restenos...

Treatment of subclavian–axillary vein thrombosis: long-term outcome of anticoagulation versus systemic thrombolysis

OBJECTIVE To investigate long-term clinical and morphological outcome of patients with subclavian-axillary vein thrombosis treated with systemic thrombolysis compared to anticoagulation in a retrospective, nonrandomised study. METHODS We studied 95 consecutive inpatients with subclavian-axillary vein thrombosis treated either with systemic urokinase thrombolysis and subsequent oral anticoagulation (n=33) or with anticoagulation only (n=62). Anticoagulation was performed with heparin and phenprocoumon. Patients were followed for median 40 months (IQR 14 to 94) for symptomatic upper extremity post-thrombotic syndrome and for venous recanalisation by duplex ultrasound. RESULTS Primary technical success rate of the systemic thrombolysis was 88% (n=29) with seven peri-intervention bleeding complications (21%). No complication was observed in patients with anticoagulation only (p<0.0001). At the time of follow-up, duplex sonography showed a thrombotic subclavian vein in 40 of 83 patients (48%), but only 9 of 95 patients (10%) had a symptomatic upper extremity post-thrombotic syndrome. Patients with systemic thrombolysis exhibited a 60% adjusted reduced risk for a thrombotic subclavian vein at the time of follow-up compared to patients with anticoagulation only (95% CI: 0.2 to 0.9, p=0.03). However, the frequency of symptomatic post-thrombotic syndrome after thrombolysis and anticoagulation was similar (adjusted p=0.6). CONCLUSION Systemic thrombolysis of subclavian-axillary vein thrombosis has an acceptable primary technical success rate and improves venous recanalisation rates compared to anticoagulation. However, the high rate of complications during thrombolysis and the lack of clinical benefit suggest that conservative treatment may be favoured.

Restenosis after Percutaneous Transluminal Angioplasty in the Femoropopliteal Segment: The Role of Inflammation

Purpose: To determine the value of baseline C-reactive protein (CPR), fibrinogen, and white blood cell (WBC) counts in predicting 1-year patency after percutaneous transluminal angioplasty (PTA) in the femoropopliteal segment. Methods: In a retrospective cohort study, 168 consecutive patients (103 men; median age 70 years, interquartile range 61–77) who underwent successful PTA of the femoral and/or popliteal arteries were analyzed. Twelve-month patency was evaluated using oscillography, ankle brachial index, duplex sonography, and angiography. The predictive value of inflammatory markers was assessed in a multivariate model controlling for cardiovascular risk factors, technical success, and hemodynamic factors. Results: Transient WBC elevation was found 6 hours after PTA, but this returned to baseline after 24 hours. Fibrinogen was elevated at 24 hours. Duplex scanning disclosed restenosis in 66 (39%) patients within the first 12 months after PTA. Only residual postdilation stenosis (≥30%) in the target segment (odds ratio 3.6, p=0.001) and baseline CRP levels (odds ratio 4.2, p=0.02) were independent predictors of outcome; neither WBC counts nor fibrinogen levels at any time point was associated with restenosis. Conclusions: Primary technical success and postinterventional hemodynamic flow at the dilated segment seem to be more important for intermediate-term patency than atherogenic risk factors. The predictive value of preprocedural serum CRP levels on restenosis should be further investigated.

Single-center experience with carotid stent restenosis.

Purpose: To report the angiographic morphology of carotid stent restenosis and the possible therapies based on data from a single-center experience. Methods: In a 45-month period, 279 patients (196 men; mean age 70 ± 9 years, range 50–89) underwent successful Wallstent placement in 303 stenotic internal carotid arteries (ICA). Patients were followed with duplex sonography; angiography was used to confirm any significant (≥70%) recurrent lesions detected on the ultrasound scan. Further balloon dilation with or without stent placement was undertaken. Results: Over a median 12-month follow-up (interquartile range 6–24), there were 9 (3.0%) carotid stent restenoses found, all within 12 months after stent placement. Two types of restenosis were differentiated. In the more common form, “in-stent” stenoses (n = 6) were detected and treated with stent placement; lasting success (patency >12 months after retreatment) was achieved in 4. Early second and third recurrences arose in the other 2 stents within 3 months of the first retreatment; additional stents were placed at each recurrence. Both patients suffered a major cerebral event after 17 months. Less often, an “end of stent” stenosis (n = 3) developed at a kink in the ICA adjacent to the cephalad end of the stent. Lasting success was achieved by balloon dilation without additional stent placement in all 3 cases. No procedure-related complications were observed within 30 days after any treatment for restenosis. Conclusions: Carotid stent restenosis, which occurs rarely after 1 year, can be treated safely by further percutaneous interventions.

Balloon angioplasty and stent implantation induce a vascular inflammatory reaction.

PURPOSE To investigate whether peripheral balloon angioplasty with and without stent implantation independently causes an inflammatory vascular response measured by serum acute-phase reactants. METHODS This was a prospective cohort study enrolled 388 consecutive patients (218 men; median age 70 years, interquartile range 59-76) with peripheral artery disease undergoing balloon angioplasty (n = 187), stent implantation (n = 140), and diagnostic angiography (control group, n = 61). C-reactive protein (CRP) measured by standard and high-sensitivity assays, serum amyloid A (SAA), fibrinogen, and white blood cell (WBC) count were obtained at baseline and at 8, 24, and 48 hours postintervention. Polynomial logistic regression analysis was used to assess the independent association of acute-phase reactants and the interventional group. RESULTS CRP levels measured by both standard and the high-sensitivity assays significantly increased after balloon angioplasty (standard CRP, p = 0.02; high-sensitivity CRP, p = 0.02) and stent implantation (standard CRP, p = 0.004; high-sensitivity CRP, p = 0.008) compared to the control group adjusting for age, sex, duration of fluoroscopy, volume of contrast, and periprocedural complications. SAA values differed only between the stent group and controls (p = 0.05). Fibrinogen and WBCs were not different among the 3 interventional groups. CONCLUSIONS Balloon injury and stent implantation induce a vascular inflammatory response at the dilated vessel segment measurable by serum acute-phase parameters. The standard CRP assay is adequate to quantify acute-phase response in these patients.

Plaque echolucency is not associated with the risk of stroke in carotid stenting.

Background and Purpose— Plaque characteristics are suggested to play a potentially important role as risk factors for poor outcome after carotid artery stenting (CAS). We therefore correlated objectively and subjectively determined carotid plaque morphology with neurological complications after CAS. Methods— We enrolled 698 consecutive patients undergoing elective CAS from a prospective single-center registry database and classified the preinterventional plaque status according to gray-scale median levels and the standardized Beletsky and Gray-Weale plaque scores. Patients were followed for 30-day neurological complications. Results— Neurological complications including transient ischemic attack, minor and major stroke occurred in 5.9% (41/698) of the patients. Median gray-scale median, Beletsky and Gray-Weale scores were 45 (interquartile range [IQR] 25 to 70), 3.0 (IQR 2.0 to 3.0) and 2.0 (IQR 2.0 to 3.0), respectively. None of the scores was significantly associated with adverse outcome adjusting for traditional risk factors, medication, preinterventional symptoms, degree of stenosis, contralateral occlusion and use of cerebral protection, neither with respect to all neurological complications nor with respect to stroke and death (all P>0.05). Conclusions— Plaque echolucency measured by objective and subjective grading did not identify patients with an increased risk of peri-interventional neurological events. Evaluation of plaque echolucency therefore cannot be recommended for risk stratification in CAS patients.