Acute Left Atrial Appendage Thrombus Formation During Transcatheter Mitral Valve Edge-to-Edge Repair.

We present a case of a 75-year-old man who developed an acute left atrial appendage thrombus immediately following mitral valve transcatheter edge to edge repair despite adequate intraprocedural anticoagulation. The patient was managed with enoxaparin to warfarin bridging with no obvious thromboembolic events on follow-up. Attention to anticoagulation is important to reduce thromboembolic risk during mitral valve transcatheter edge to edge repair. (Level of Difficulty: Intermediate.).

Heavy lone coronary artery thrombosis treated by stent retriever, in the setting of COVID-19 infection.

We present a case of heavy lone coronary thrombosis in the setting of COVID-19 infection. We highlight the special angiographic, ultrasonographic, and histological features of this thrombus, and we describe the application of carotid stent retriever for its removal.

A 31-Year-Old Man With Angina Pectoris Resulting From Large Vessel Vasculitis.

We present the case of an apparently healthy 31-year-old man with malignant progression of coronary artery disease and recurrent angina resulting from suspected large vessel vasculitis. This case highlights the importance of considering vasculitis in patients without atherosclerotic risk factors, using a multidisciplinary team approach, and suppressing inflammation before coronary revascularization to improve outcomes. (Level of Difficulty: Beginner.).

Combined Transradial and Transfemoral Approach With Ostial Vertebral Balloon Protection for the Treatment of Patients With Subclavian Steal Syndrome.

Background: Patients with an obstructive subclavian artery (SA) may exhibit symptoms of vertebrobasilar insufficiency known as subclavian steal syndrome (SSS). Endovascular treatment with stent assisted percutaneous transluminal angioplasty (SAPTA) demonstrates significantly lower percentage of intraoperative and postoperative complications in comparison with open surgery. There is a 1-5% risk of distal intracranial embolization through the ipsilateral vertebral artery (VA) during SAPTA. Objective: To assess the safety and feasibility of a novel technique for distal embolic protection using balloon catheters during SA revascularization with a dual transfemoral and transradial access. Methods: We describe a case series of patients with SSS who underwent SAPTA due to severe stenosis or occlusion of the SA using a combined anterograde/retrograde approach. Transfemoral access to SA was obtained using large bore guide sheaths. Ipsilateral transradial access was obtained using intermediate bore catheters. A Scepter XC balloon catheter was introduced through the transradial intermediate catheter into the ipsilateral VA at the ostium during SAPTA for distal embolic protection. Results: A total of eight patients with SSS underwent subclavian SAPTA. Four patients had the combined anterograde/retrograde approach. Successful revascularization was achieved in three of them. It was difficult to create a channel in the fourth unsuccessful case due to heavily calcified plaque burden. No peri-operative ischemic events were identified. On follow-up, we demonstrated patency of the stents with resolution of symptoms and without any adverse events. Conclusion: Subclavian stenting using a combined transradial and transfemoral access with compliant balloon catheters at the vertebral ostium for prevention of distal emboli may represent an alternative therapeutic approach for the treatment of SA stenosis and occlusions.

Incidence, Predictors, and Outcomes of Endocarditis After Transcatheter Aortic Valve Replacement in the United States.

OBJECTIVES: This study sought to evaluate the incidence and outcomes of endocarditis after transcatheter aortic valve replacement (TAVR). BACKGROUND: Data about endocarditis after TAVR are limited. METHODS: The study investigated Medicare patients who underwent TAVR from 2012 to 2017 and identified patients admitted with endocarditis during follow-up using a validated algorithm. The main study outcome was all-cause mortality. RESULTS: Of 134,717 patients who underwent TAVR, 1868 patients developed endocarditis during follow-up (incidence 0.87%/year), with majority of infections (65.0%) occurring within 1 year. Incidence of endocarditis declined in recent years. The most common organisms were Staphylococcus (22.0%), Streptococcus (20.0%), and Enterococcus (15.5%). Important predictors for endocarditis were younger age at TAVR, male sex, prior endocarditis, end-stage renal disease, repeat TAVR procedures, liver and lung disease, and post-TAVR acute kidney injury. Thirty-day and 1-year mortality were 18.5% and 45.6%, respectively. After adjusting for comorbidities and procedural complications, endocarditis after TAVR was associated with 3-fold higher risk of mortality (44.9 vs. 16.2 deaths per 100 person-years; adjusted hazard ratio [aHR]: 2.94; 95% confidence interval [CI]: 2.77 to 3.12; p < 0.0001). End-stage renal disease (aHR: 2.12; 95% CI: 1.72 to 2.60), endocarditis complicated by cardiogenic shock (aHR: 2.50, 95% CI: 1.56 to 4.02), ischemic stroke (aHR: 1.56; 95% CI: 1.07 to 2.28), intracerebral hemorrhage (aHR: 1.67; 95% CI: 1.01 to 2.76), acute kidney injury (aHR: 1.44; 95% CI: 1.27 to 1.63), blood transfusion (aHR: 1.28; 95% CI: 1.09 to 1.50), staphylococcal (aHR: 1.71; 95% CI: 1.49 to 1.97), and fungal endocarditis (aHR: 1.72; 95% CI: 1.23 to 2.39) (p < 0.05 for all) portended higher mortality following endocarditis. CONCLUSIONS: The incidence of endocarditis after TAVR is low and declining. However, it is associated with poor prognosis with one-half the patients dying within 1 year.

Management of Aortic Stenosis in Patients With End-Stage Renal Disease on Hemodialysis.

BACKGROUND: Patients with end-stage renal disease on hemodialysis (ESRD-HD) and aortic stenosis have poor prognosis. The role of transcatheter aortic valve replacement (TAVR) in this high-risk population is debated. METHODS: We compared the outcomes among ESRD-HD Medicare beneficiaries who were managed with TAVR, surgical AVR (SAVR), or conservative management for aortic stenosis between 2015 and 2017, using overlap propensity score weighting analysis to control for differences in treatment assignment. The primary outcome was all-cause mortality and was compared between treatment groups as well as to age-sex matched mortality for ESRD-HD in the US population. Secondary outcomes included trend of heart failure hospitalizations. RESULTS: A total of 8107 ESRD-HD patients with aortic stenosis were included, 4130 (50%) underwent TAVR, 2565 (31.6%) underwent SAVR, and 1412 (17.4%) were managed conservatively. TAVR patients had more comorbidities and higher frailty compared with the other 2 groups. Thirty-day mortality was lower with TAVR compared with SAVR (4.6% versus 12.8%, P<0.01). After a median follow-up of 465 days (interquartile range, 261-759), on overlap propensity score weighting analysis, there was no difference in mortality between TAVR and SAVR (adjusted hazard ratio, 1.02 [95% CI, 0.91-1.15], P=0.7), and mortality was lower with TAVR compared with conservative management (adjusted hazard ratio, 0.53 [95% CI, 0.47-0.60], P<0.001). Standardized mortality ratios with TAVR, SAVR, and conservative management compared with age-sex matched ESRD-HD US population were 1.24, 1.27, and 1.83, respectively. The rate of heart failure admissions declined after TAVR (incidence rate ratio, 0.55 [95% CI, 0.48-0.62], P<0.001) and SAVR (incidence rate ratio, 0.76 [95% CI, 0.65-0.88], P<0.001). CONCLUSIONS: In ESRD-HD patients with aortic stenosis, mortality was lower in the short-term with TAVR compared with SAVR but comparable in the mid-term. AVR is associated with an improvement in survival and reduction in heart failure hospitalizations compared with conservative management.

Incidence and Outcomes of Acute Coronary Syndrome After Transcatheter Aortic Valve Replacement.

OBJECTIVES: This study sought to address a knowledge gap by examining the incidence, timing, and predictors of acute coronary syndrome (ACS) after transcatheter aortic valve replacement (TAVR) in Medicare beneficiaries. BACKGROUND: Evidence about incidence and outcomes of ACS after TAVR is scarce. METHODS: We identified Medicare patients who underwent TAVR from 2012 to 2017 and were admitted with ACS during follow-up. We compared outcomes based on the type of ACS: ST-segment elevation myocardial infarction (STEMI), non-STEMI (NSTEMI), and unstable angina. In patients with non-ST-segment elevation ACS, we compared outcomes based on the treatment strategy (invasive vs. conservative) using inverse probability weighting analysis. RESULTS: Out of 142,845 patients with TAVR, 6,741 patients (4.7%) were admitted with ACS after a median time of 297 days (interquartile range: 85 to 662 days), with 48% of admissions occurring within 6 months. The most common presentation was NSTEMI. Predictors of ACS were history of coronary artery disease, prior revascularization, diabetes, valve-in-TAVR, and acute kidney injury. STEMI was associated with higher 30-day and 1-year mortality compared with NSTEMI (31.4% vs. 15.5% and 51.2% vs. 41.3%, respectively; p < 0.01). Overall, 30.3% of patients with non-ST-segment elevation ACS were treated with invasive approach. On inverse probability weighting analysis, invasive approach was associated with lower adjusted long-term mortality (adjusted hazard ratio: 0.69; 95% confidence interval: 0.66 to 0.73; p < 0.01) and higher risk of repeat revascularization (adjusted hazard ratio: 1.29; 95% confidence interval: 1.16 to 1.43; p < 0.001). CONCLUSIONS: After TAVR, ACS is infrequent (<5%), and the most common presentation is NSTEMI. Occurrence of STEMI after TAVR is associated with a high mortality with nearly one-third of patients dying within 30 days. Optimization of care is needed for post-TAVR ACS patients and if feasible, invasive approach should be considered in these high-risk patients.

Intracranial Atherosclerosis: A Disease of Functional, not Anatomic Stenosis? How Trans-Stenotic Pressure Gradients Can Help Guide Treatment.

BACKGROUND: Most trials have assessed intracranial atherosclerotic disease (ICAD) severity based on angiographic stenosis. However, anatomic stenosis might not accurately identify the actual state of functional post-stenotic flow limitation. OBJECTIVE: To investigate whether angiographic stenosis correlates with physiologic distal flow limitation, measured as trans-stenotic pressure gradients, in ICAD patients. METHODS: In patients referred for endovascular treatment of anterior circulation symptomatic ICAD who failed maximal medical therapy (MMT) per SAMMPRIS (Stenting versus Aggressive Medical Therapy for Intracranial Arterial Stenosis) criteria, angiographic luminal diameters and percentages of stenosis were correlated with trans-stenotic pressure gradients, calculated as distal/proximal pressure ratios (DPPR) and proximal minus distal pressure gradients (PDPG), by way of Spearman correlation coefficients. RESULTS: Nine patients (3 men, 6 women) were evaluated. Atherosclerotic lesions' locations included internal carotid artery in 5 subjects (2 cavernous, 3 supraclinoid) and proximal middle cerebral artery (M1) in 4 patients. Mean percentage of stenosis was 80 ± 8% (range 75%-94%). Minimal lumen diameter at the most stenotic ICAD site ranged from 0.2 to 0.9 mm (0.59 ± 0.41 mm). DPPR ranged from 0.38 to 0.63 (0.56 ± 0.14). PDPG ranged from 35 to 57 mm Hg (50 ± 8 mm Hg). Spearman coefficients showed no correlation between DPPR or PDPG and angiographic minimal luminal diameters or percentages of stenosis. There were no procedural complications related to trans-stenotic pressure measurements. CONCLUSION: Angiographic stenosis does not reflect the physiologic severity of distal flow limitation in patients with ICAD. Hemodynamic assessment using trans-stenotic pressure ratios and gradients may serve as a more reliable predictive biomarker for MMT failure and response to revascularization.

Temporal Trends and Clinical Outcomes of Transcatheter Aortic Valve Replacement in Nonagenarians.

Background Contemporary outcomes of transcatheter aortic valve replacement (TAVR) in nonagenarians are unknown. Methods and Results We identified 13 544 nonagenarians (aged 90-100 years) who underwent TAVR between 2012 and 2016 using Medicare claims. Generalized estimating equations were used to study the change in short-term outcomes among nonagenarians over time. We compared outcomes between nonagenarians and non-nonagenarians undergoing TAVR in 2016. A mixed-effect multivariable logistic regression was performed to determine predictors of 30-day mortality in nonagenarians in 2016. A center was defined as a high-volume center if it performed ≥100 TAVR procedures per year. After adjusting for changes in patients' characteristics, risk-adjusted 30-day mortality declined in nonagenarians from 9.8% in 2012 to 4.4% in 2016 (P<0.001), whereas mortality for patients <90 years decreased from 6.4% to 3.5%. In 2016, 35 712 TAVR procedures were performed, of which 12.7% were in nonagenarians. Overall, in-hospital mortality in 2016 was higher in nonagenarians compared with younger patients (2.4% versus 1.7%, P<0.05) but did not differ in analysis limited to high-volume centers (2.2% versus 1.7%; odds ratio: 1.33; 95% CI, 0.97-1.81; P=0.07). Important predictors of 30-day mortality in nonagenarians included in-hospital stroke (adjusted odds ratio [aOR]: 8.67; 95% CI, 5.03-15.00), acute kidney injury (aOR: 4.11; 95% CI, 2.90-5.83), blood transfusion (aOR: 2.66; 95% CI, 1.81-3.90), respiratory complications (aOR: 2.96; 95% CI, 1.52-5.76), heart failure (aOR: 1.86; 95% CI, 1.04-3.34), coagulopathy (aOR: 1.59; 95% CI, 1.12-2.26; P<0.05 for all). Conclusions Short-term outcomes after TAVR have improved in nonagenarians. Several procedural complications were associated with increased 30-day mortality among nonagenarians.

Second Generation Drug-Eluting Stents for Endovascular Treatment of Ostial Vertebral Artery Stenosis: A Single Center Experience.

Objective: To report a single-center experience using drug-eluting balloon mounted stents (DES) for endovascular treatment of atherosclerotic ostial vertebral artery stenosis (OVAS). Background: Posterior circulation is affected in up to 25% of strokes, 20% of them resulting from atherosclerotic OVAS. The optimal management of symptomatic OVAS remains controversial. DES have been introduced to improve restenosis rates. Methods: We retrospectively analyzed prospectively collected data from patients with dominant OVAS who underwent endovascular treatment with second-generation DES placement. Patient demographics, clinical presentation, comorbidities, stenosis severity, stent features, technical success, complications, and imaging follow-up were assessed. Results: Thirty patients were treated, predominantly male (86.6%). Sixteen patients presented with an acute stroke or TIA and fourteen were treated on an elective basis due to symptomatic chronic stenosis and contralateral occlusion. Comorbidities included hyperlipidemia (83%), hypertension (70%) and prior stroke (63.3%). Mean ostial stenosis at presentation was 80 ± 14.8%. Twenty-one patients had contralateral VA involvement. DES deployment was technically successful in all patients using everolimus eluting stents in 30 lesions and zotarolimus eluting stents in two. One technical complication (stent migration) and three (10%) minor peri-procedural complications occurred. Complications included one asymptomatic ischemic infarct in the posterior circulation, one femoral artery thrombosis and one post-procedure altered mental status secondary to contrast induced neurotoxicity. Mean imaging follow-up was 8.8 months. Two (7.6%) patients had in-stent restenosis and underwent retreatment with angioplasty. There were no procedure-related mortalities. Conclusion: Our study confirms the feasibility of deploying DES for the treatment of ostial vertebral artery stenosis with low peri-procedural risk and low medium-term rates of re-stenosis.

Bradycardia and Asystole in Patients Undergoing Symptomatic Chronically Occluded Internal Carotid Artery Recanalization.

BACKGROUND: Reports have emerged describing the successful endovascular recanalization of the chronically occluded internal carotid artery (COICA). The impact this restoration of flow has on the sensitive carotid sinus baroreceptors has not been previously described. In this manuscript, we present the largest COICA surgical series to date, with a specific focus on perioperative heart rate abnormalities. METHODS: Patient demographics were obtained, and the COICAs were radiographically classified based on the anatomic distribution of the stenosis and collateral flow. Thirty-six patients had a total of 37 COICA revascularization procedures. RESULTS: A total of 23 patients had intraprocedural bradycardia during balloon angioplasty. Three patients went into transient asystole during the procedure, and 2 of these patients had symptomatic bradycardia with ischemic cerebral changes, 1 of which required permanent pacemaking. All other patients had immediate resolution of their bradycardia, asystole, and neurologic symptoms immediately following balloon deflation and pharmaceutical management. There was a statistically significant difference in the observed proportion of bradycardic patients among COICA classifications (P = 0.014). There was no statistically significant difference in mean age between patients with bradycardia and those without (aged 63.36 vs. 67.71 years, P = 0.2265). CONCLUSIONS: Bradycardia associated with angioplasty of the carotid bulb was observed in the majority of patients receiving COICA revascularization. A small percentage of these patients were symptomatic. Our results suggest that carotid sinus baroreceptors remain active while residing in a complete arterial occlusion, and close monitoring is necessary during balloon angioplasty of the proximal COICA.

Transcatheter Repair of Anterior Mitral Leaflet Perforation: Deploy, Retrieve, Redeploy.

We describe a case of anterior mitral leaflet perforation successfully treated with the Amplatzer Cribriform device, with resultant hemolytic anemia. The device was retrieved, and perforation occluded with the GORE CARDIOFORM device with resolution of hemolysis. (Level of Difficulty: Advanced.).

Endovascular Treatment of Ruptured Vertebrobasilar Dissecting Aneurysms Using Flow Diversion Embolization Devices: Single-Institution Experience.

OBJECTIVE: Treatment of ruptured posterior circulation dissecting aneurysms is technically challenging with potentially high morbidity and mortality. We sought to assess the safety and feasibility of using a flow-diversion device (FDD) and a specific acute antiplatelet aggregation protocol in the management of ruptured dissecting aneurysms. METHODS: Subjects with ruptured dissecting aneurysms treated during a 3-year period were retrospectively identified from a prospective registry. Intraoperative complications, morbidity, and mortality were recorded. Tirofiban maintenance infusion without bolus was administered intravenously immediately after deployment of the FDD, and almost all patients were loaded with dual antiplatelet (aspirin and clopidogrel) post procedure. Clinical follow-up evaluation and modified Rankin Scale were assessed. RESULTS: Nine subjects with ruptured posterior circulation dissecting aneurysms were treated with an FDD: 5 vertebral artery, 2 basilar artery, and 2 posterior inferior cerebellar artery aneurysms. Average World Federation of Neurosurgical Societies score was 2 (range 1-5). Seven patients had external ventricular drain placed acutely for hydrocephalus. Eight patients received tirofiban infusion without bolus after FDD. No intraoperative complications occurred. Two subjects developed asymptomatic intraparenchymal hemorrhage found on surveillance noncontrast computed tomography. One subject suffered a major intraparenchymal hemorrhage and died a few days post intervention after additional anticoagulation was started for a left ventricular assist device. Follow-up modified Rankin Scale within 12 months was 0 in 3 subjects, 1 in 3 subjects, 2 in 1 subject, and 4 in 1. CONCLUSIONS: Treatment of dissecting posterior circulation aneurysms with FDDs is feasible and a potential alternative to deconstructive techniques.

Hybrid Retrograde-Antegrade Recanalization of Acute Basilar Artery Occlusion.

Acute basilar artery (BA) occlusion has a very poor prognosis. Recanalization can be challenged by bilateral vertebral artery (VA) occlusions, arterial dissection, or advanced atherosclerotic disease. We describe a case in whom the BA was accessed and recanalized through a retrograde-antegrade approach from the anterior circulation using a large posterior communicating artery (PCOM). Once the BA had been crossed retrogradely through the PCOM, another microcatheter was advanced antegradely through the VA into the BA and right posterior cerebral artery using the "buddy-wire" technique. In this way the BA was recanalized and reconstructed with stents. This technical note demonstrates a new approach to BA treatment when the antegrade access is hampered by advanced VA/BA disease or dissection.

Giant saphenous vein graft pseudoaneurysm to right posterior descending artery presenting with superior vena cava syndrome.

Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late complication of coronary artery bypass grafting. This condition affects both genders and typically occurs within the sixth decade of life. The clinical presentation ranges from an asymptomatic incidental finding on imaging studies to new onset angina, dyspnea, myocardial infarction or symptoms related to compression of neighboring structures. An 82-year-old woman presented with acute onset back pain, dyspnea and was noted to have significantly engorged neck veins. In the emergency department, a chest computed tomographic angiogram with intravenous contrast revealed a ruptured giant bilobed SVG pseudoaneurysm to the right posterior descending artery (RPDA). This imaging modality also demonstrated compression of the superior vena cava (SVC) by the SVG pseudoaneurysm. Coronary angiogram with bypass study was performed to establish the patency of this graft. Endovascular coiling and embolization of the SVG to RPDA was initially considered but disfavored after the coronary angiogram revealed preserved flow from the graft to this arterial branch. After reviewing the angiogram films, a surgical strategy was favored over a percutaneous intervention with a Nitinol self-expanding stent since the latter would have not addressed the superior vena cava compression caused by the giant pseudoaneurysm. Intraoperative transesophageal echocardiogram demonstrated SVC compression by the giant pseudoaneurysm cranial lobe. Our patient underwent surgical ligation and excision of the giant pseudoaneurysm and the RPDA was regrafted successfully. In summary, saphenous vein grafts pseudoaneurysms can be life-threatening and its therapy should be guided based on the presence of mechanical complications, the patency of the affected vein graft and the involved myocardial territory viability.

Prevalence and outcomes of intermediate saphenous vein graft lesions: findings from the stenting of saphenous vein grafts randomized-controlled trial.

BACKGROUND: We sought to examine the prevalence and progression rate of intermediate saphenous vein graft (SVG) lesions in the Stenting Of Saphenous vein grafts (SOS) trial. METHODS: The baseline and follow-up angiograms of 80 patients participating in the SOS trial were analyzed to determine the prevalence of intermediate (30-60% angiographic diameter stenosis) SVG lesions and their progression rate. RESULTS: At least one intermediate SVG lesion was present in 31 of 143 (22%) SVGs in 27 of 80 (34%) patients. Most intermediate lesions were present in the SOS stented SVGs (20 grafts in 19 patients). During a median follow-up of 35 months, angiographic follow-up was available for 28 grafts in 25 patients. Progression (defined as percent diameter stenosis ≥ 70% but <100% at follow-up angiography) was seen in 11 of 28 SVGs (39%) in 11 of 25 patients (44%). Progression rate at 12, 24 and 36 months was 28% and 47% and 84%, respectively. Seven of 11 patients (64%) with intermediate SVG lesion progression presented with an acute coronary syndrome and 8 (73%) underwent PCI. Four of the 28 grafts with intermediate lesions at baseline were 100% occluded at follow-up; all of those SVGs had received a stent in another location in the SVG as part of the SOS trial. CONCLUSIONS: Intermediate SVG lesions are common in patients undergoing SVG stenting, have high rates of progression and frequently present with an acute coronary syndrome. Further study of pharmacologic and mechanical treatments to prevent progression of these lesions is needed.

Incidence of cerebral ischemic events after discontinuation of clopidogrel in patients with intracranial aneurysms treated with stent-assisted techniques.

OBJECT: The optimal antiplatelet medication protocol for prevention of thrombotic complications after stent-assisted coil embolization of cerebral aneurysms is unclear. Early cessation of antiplatelet agents may be associated with an increased risk of cerebral ischemic events. In this study, the authors assess the incidence of stroke or transient ischemic attack (TIA) following discontinuation of a 6-week course of clopidogrel in patients with cerebral aneurysms treated with stent-assisted techniques. METHODS: A retrospective review was conducted in all patients with cerebral aneurysms undergoing stent-assisted coil embolization or stent-in-stent flow diversion at the University of Iowa during a 24-month period. The antiplatelet protocol was 81 mg aspirin and 75 mg clopidogrel daily for 6 weeks, followed by 325 mg aspirin daily indefinitely. The incidence of stroke or TIA was determined by a retrospective review of medical records generated during a 3-month period following discontinuation of clopidogrel. RESULTS: A total of 154 patients underwent aneurysm treatment with stent techniques during this interval. Documentation of neurological follow-up 3 months after discontinuation of a 6-week clopidogrel treatment was available in 121 (78.6%) of 154 patients. Of these 121 patients, 114 were treated with stent-assisted coil embolization and 7 with stent-in-stent flow diversion. Six patients (5%) suffered an ischemic event after cessation of clopidogrel, with 2 events occurring within the first 2 weeks. Specifically, the rate of ischemic events was 5 (4.3%) of 114 in the "stent-coil" treatment group and 1 (14.3%) of 7 in the stent-in-stent group. Treatment had been performed in the setting of a subarachnoid hemorrhage in 1 patient. Atypical aneurysm features and technical factors predisposing to thrombotic events were found in all but one of these patients. Similarly, cardiovascular risk factors were present in 5 of the 6 patients in whom ischemic events developed after clopidogrel discontinuation. CONCLUSIONS: Clopidogrel discontinuation is associated with a 5% risk of ischemic events in patients treated with stent techniques. Any stroke related to clopidogrel discontinuation is avoidable, and longer treatment is therefore clearly necessary. Patients with cardiovascular risk factors, high-risk aneurysm features, and those undergoing stent-in-stent flow diversion might benefit the most from longer clopidogrel therapy.