Proximal Occlusion Research Articles

Development of the Circle of Willis Score (COWS) to help guide decision making during acute tandem occlusion treatment: Preliminary analysis

BackgroundAcute tandem occlusions (TOs) are challenging to treat. Although acute carotid stenting of the proximal lesion is well tolerated, there are certain situations when the practitioner may be wary of acute stenting (bleeding concerns). ObjectiveThe purpose of this study was to retrospectively study patients with tandem occlusions who had re-occlusion of the extracranial ICA and develop a Circle of Willis Score (COWS) to help predict which patients could forego acute stenting. MethodsThis is a retrospective review of TO patients with a persistent proximal occlusion following intervention (either expected or unexpected). Pre intervention CTA and intraoperative DSA were reviewed, and each patient was assigned a score 2 (complete COW), 1a (patent A1-Acomm-A1), 1p (patent Pcomm), or 0 (incomplete COW). Findings from the DSA took precedence over the CTA. Two cohorts were created, the complete COW cohort (COWS 2) versus the incomplete COW cohort (COWS 1a,1p, or 0). Angiographic outcomes were assessed using the mTICI score (2b-3) and clinical outcomes were assessed using discharge mRS (good outcome mRS 0–3). ResultsOf 68 TO cases, 12 had persistent proximal occlusions. There were 5/12 (42 %) patients in the complete COW cohort, and 7/12 (58 %) in the incomplete COW cohort (5/12 with scores of 1a/1p and 2/12 with a score of 0). In the complete COW cohort, there were 2 ICA-ICA and 3 ICA-MCA occlusions. In the incomplete COW cohort, there was one ICA-ICA occlusion and 6 ICA-MCA occlusions. LKW-puncture was shorter in the complete COW cohort (208 min vs. 464 min, p = 0.16). Successful reperfusion was higher in the complete COW cohort (100 % vs. 71 %). There was a trend toward better clinical outcomes in the complete COW cohort (80 % vs 29 %, p = 0.079). ConclusionThe COWS is a simple score that may help predict a successful clinical outcome without proximal revascularization when concerned about performing an acute carotid stent during TO treatment. Evaluation in larger TO cohort is warranted.

Infarto com Supra-ST em Adulto Jovem: Rara Apresentação de Mixoma Atrial Gigante

Abstract Cardiac tumors are rare entities, among which atrial myxoma (AM) stands as the most frequent, accounting for approximately half of all reported cases. The incidence of AM is estimated to range from 0.001% to 0.3% within the general population, yet only about 0.06% of these cases present with coronary embolic events. We report on a 33-year-old male smoker who experienced acute, severe precordial pain radiating to the left upper limb, lasting for one hour. The electrocardiographic evaluation demonstrated ST-segment elevation in leads D2, D3, and aVF, alongside significantly elevated serum troponin levels, confirming a diagnosis of ST-segment elevation myocardial infarction (STEMI). Subsequent coronary angiography revealed proximal occlusion of the right coronary artery due to thrombus. An initial attempt of thrombus aspiration was unsuccessful, followed by primary angioplasty with balloon inflation without stent placement. Further diagnostic exploration through transthoracic echocardiography identified a homogenous, smooth-surfaced mass measuring 5.2 cm x 2.3 cm attached to the interatrial septum. This mass, characterized by lobulations, prolapsed into the mitral valve and left ventricle during diastole, consistent with AM. Surgical resection of the mass was successfully performed, with the patient being discharged asymptomatic. In the reported case, the patient's profile, notably his age, and gender, diverges from the typical epidemiological characteristics associated with AM. This case adds to the limited number of reports where the inferior wall is affected by the right coronary artery being occluded. This report emphasizes the significance of differential diagnoses in younger patients presenting with STEMI.

THE INFLUENCE OF VESSEL CURVATURE AND THROMBUS COMPOSITION ON THE EFFECTIVENESS AND OUTCOMES OF THROMBECTOMY IN THE CASE OF ACUTE ISCHEMIC STROKE

Introduction. It is believed that vascular anatomy has a direct influence on the complexity and course of mechanical thrombectomy, and its outcome determines the degree of reperfusion and clinical effect.
 Aim. To analyze the influence of the curvature of the intracranial arteries and the composition of the thrombus on the results of thrombectomy.
 Materials and methods. 64 patients who underwent mechanical thrombectomy for acute proximal occlusion of the ICA or MCA were prospectively examined. (44man/20women among them, the age of the patients ranged from 47-89years (67.2±1.2). The study was performed by measuring the ICA-M1 angle on angiograms in direct projection. Angles were compared between patients with successful (mTICI group 2b/3) and unsuccessful (mTICI group 0-2a) reperfusion. The functional result was evaluated according to the mRS scale as positive (0-3) and negative (4-5). Removed thrombi were examined by light microscopy with hematoxylin-eosin and orange-red-blue staining.
 Results. Among patients of the mTICI 2b/3 group, a larger angle of the ICA-M1 was measured (126.4±2.8°) compared to patients in the mTICI 0-2a group - 107.1±4.9° (p=0.05). Among patients with 1-2 passages, statistically significantly larger ICA-M1 angles were recorded (129.8±3.3°) than among patients with a number of passages >2 (109.2±5,7°, p<0.02). The duration of mechanical thrombectomy was <60min among patients with larger angles of the ICA-M1 (127.6±4.4° vs. 119.6±4.5°) than in patients with long interventions (>60 min) (p<0.05). Successful reperfusion (group mTICI 2b/3) was achieved in 47 (73.4%) patients. A clinically positive result(mRS 0-3) was observed among 37(57.8%) patients.
 During microscopic examination of thrombi among patient groups mTICI 0/2a, fibrin threads with signs of aging with purple and blue color were present on the periphery (24-48hours). With a favorable outcome of the operation, the coagulated fibrin fibers were stained red (<16hours).
 Conclusions. With a smaller curvature of the ICA and its branches, and in the presence of "fresh" thrombi, the efficiency of operations increases, and the number of passages and the duration of mechanical thrombectomy decrease. The neurological status of patients at admission correlates with the functional outcome at the time of discharge.

Pretreatment parameters associated with hemorrhagic transformation among successfully recanalized medium vessel occlusions.

Although pretreatment radiographic biomarkers are well established for hemorrhagic transformation (HT) following successful mechanical thrombectomy (MT) in large vessel occlusion (LVO) strokes, they are yet to be explored for medium vessel occlusion (MeVO) acute ischemic strokes. We aim to investigate pretreatment imaging biomarkers representative of collateral status, namely the hypoperfusion intensity ratio (HIR) and cerebral blood volume (CBV) index, and their association with HT in successfully recanalized MeVOs. A prospectively collected registry of acute ischemic stroke patients with MeVOs successfully recanalized with MT between 2019 and 2023 was retrospectively reviewed. A multivariate logistic regression for HT of any subtype was derived by combining significant univariate predictors into a forward stepwise regression with minimization of Akaike information criterion. Of 60 MeVO patients successfully recanalized with MT, HT occurred in 28.3% of patients. Independent factors for HT included: diabetes mellitus history (p = 0.0005), CBV index (p = 0.0071), and proximal versus distal occlusion location (p = 0.0062). A multivariate model with these factors had strong diagnostic performance for predicting HT (area under curve [AUC] 0.93, p < 0.001). Lower CBV indexes, distal occlusion location, and diabetes history are significantly associated with HT in MeVOs successfully recanalized with MT. Of note, HIR was not found to be significantly associated with HT.

Evaluation of CINA® LVO artificial intelligence software for detection of large vessel occlusion in brain CT angiography

ObjectiveTo systematically evaluate the ability of the CINA® LVO software to detect large vessel occlusions eligible for mechanical thrombectomy on CTA using conventional neuroradiological assessment as gold standard. MethodsRetrospectively, two hundred consecutive patients referred for a brain CTA and two hundred patients that had been subject for endovascular thrombectomy, with an accessible preceding CTA, were assessed for large vessel occlusions (LVO) using the CINA® LVO software. The patients were sub-grouped by occlusion site. The original radiology report was used as ground truth and cases with disagreement were reassessed. Two-by-two tables were created and measures for LVO detection were calculated. ResultsA total of four-hundred patients were included; 221 LVOs were present in 215 patients (54 %). The overall specificity was high for LVOs in the anterior circulation (93 %). The overall sensitivity for LVOs in the anterior circulation was 54 % with the highest sensitivity for the M1 segment of the middle cerebral artery (87 %) and T-type internal carotid occlusions (84 %). The sensitivity was low for occlusions in the M2 segment of the middle cerebral artery (13 % and 0 % for proximal and distal M2 occlusions respectively) and in posterior circulation occlusions (0 %, not included in the intended use of the software). ConclusionsLVO detection sensitivity for the CINA® LVO software differs largely depending on the location of the occlusion, with low sensitivity for detection of some LVOs potentially eligible for mechanical thrombectomy. Further development of the software to increase sensitivity to all LVO locations would increase the clinical usefulness.

High-flow bypass for giant dolichoectatic vertebrobasilar aneurysms: illustrative cases

BACKGROUND Giant fusiform dolichoectatic vertebrobasilar artery aneurysms are challenging lesions with a poor natural history. When there is progressive brainstem compression from these lesions, endovascular treatment can be insufficient, and bypass surgery remains a possible salvage option. High-flow bypass surgery with proximal occlusion can potentially arrest aneurysm growth, promote aneurysm thrombosis, and reduce rupture risk. The authors describe their experience in two patients with giant fusiform dolichoectatic vertebrobasilar artery aneurysms treated with high-flow bypass. OBSERVATIONS Both patients presented with enlarging giant dolichoectatic vertebrobasilar aneurysms causing symptomatic brainstem compression. The authors performed staged treatment involving high-flow bypass from the external carotid artery to the posterior cerebral artery using a saphenous vein graft, Hunterian proximal vertebrobasilar occlusion, and finally posterior fossa decompression with or without direct aneurysm thrombectomy and debulking. Postoperative angiography revealed successful flow reversal, aneurysm exclusion, and no brainstem stroke. Clinically, one patient had improvement in their modified Rankin Scale (mRS) score from 3 preoperatively to 1 at 12-month follow-up. The second patient had a deterioration in their mRS score from 4 to 5 at 12-month follow-up. LESSONS High-flow bypass strategies remain high risk but can be a viable last resort in patients with neurological deficits and enlarging giant fusiform dolichoectatic vertebrobasilar artery aneurysms.

Microsurgical partial trapping for the treatment of unclippable vertebral artery aneurysms: Experience from 27 patients and review of literature

BACKGROUNDThe efficacy and safety of partial trapping for the treatment of unclippable vertebral artery aneurysms (UVAs) are still questionable. The partial trapping method (proximal or distal occlusion) was used in the treatment of aneurysms to simplify the surgical procedure and avoid postoperative complications. METHODSThis study included 27 patients with UVAs who underwent microsurgical partial trapping between January 2015 and August 2022, and their postoperative outcomes and complications were retrospectively reviewed and evaluated. RESULTSRuptured UVAs were detected in 25 (92.6%) patients, and 13 (48.1%) patients had poor-grade status. Fusiform dissection, dissecting, and fusiform aneurysms were observed in 17 (63%), 7 (25.9%), and 3 (11.1%) patients, respectively. By location, preposterior inferior cerebellar artery (PICA), PICA, post- PICA, and non-PICA types were noted in 7 (25.9%), 9 (33.3%), 6 (22.2%), and 5 (18.5%) patients, respectively. Microsurgical partial trapping was performed in all patients (blind-alley formation in 96.3%). Complete aneurysm obliteration was achieved in 26 (96.3%) patients. Immediate complete obliteration was achieved in 21 (77.8%) patients, delayed thrombosis within 7 days in 5 (18.5%), and nearly complete obliteration in 1 (3.7%). No re-bleeding was detected in all patients. Favorable outcomes 3 months after the operation were achieved by 92.9% of the patients in the good-grade group and 85.2% overall. CONCLUSIONSMicrosurgical partial trapping, especially the blind-alley formation technique, was a safe and effective treatment of UVAs with high rates of aneurysm thrombosis. The appropriate sites for clip occlusion were dependent on the angioarchitecture of UVAs.

Endovascular treatment versus medical management for mild stroke with acute anterior circulation large vessel occlusion: a meta-analysis

BackgroundThe effectiveness of endovascular treatment (EVT) in patients with mild stroke (National Institutes of Health Stroke Scale score ≤5) and acute anterior circulation large vessel occlusion (AACLVO) remains unknown.ObjectiveTo conduct...

TAPSE, Tissue Doppler Systolic annular velocity(S’) and myocardial performance Index (MPI) as a predictor of proximal RCA occlusion in acute inferior wall myocardial ST elevation infarction

TAPSE, Tissue Doppler Systolic annular velocity(S’) and myocardial performance Index (MPI) as a predictor of proximal RCA occlusion in acute inferior wall myocardial ST elevation infarction

Correlation between contrast leakage period of procedural rupture and clinical outcomes in endovascular coiling for cerebral aneurysms.

Intraprocedural rupture (IPR) is a fatal complication of endovascular coiling for cerebral aneurysms. We hypothesized that contrast leakage period may be related to poor clinical outcomes. This study aimed to retrospectively evaluate the relationship between clinical outcomes and contrast leakage period. Data from patients with cerebral aneurysms treated via endovascular coiling between January 2010 and October 2018 were retrospectively assessed. The enrolled patient's demographic data, the aneurysm related findings, endovascular treatment and IPR related findings, rescue treatment, and clinical outcome were analyzed. In total, 2,859 cerebral aneurysms were treated using endovascular coiling during the study period, with IPR occurring in 18 (0.63 %). IPR occurred during initial frame coiling (n=4), coil packing (n=5), stent deployment (n=7), ballooning (n=1), and microcatheter removal after coiling (n=1). Tear sites included the dome (n=14) and neck (n=4). All IPRs were controlled and treated with coil packing, with or without stenting. Flow arrest of the proximal balloon was not observed. Temporary focal neurological deficits developed in two patients (11.1%). At clinical follow-up, 14 patients were classified as modified Rankin Scale (mRS) 0, three as mRS 2, and one as mRS 4. The mean contrast leakage period of IPR was 11.2 min (range: 1-31 min). Cerebral aneurysms with IPR were divided into late (n=9, mean time: 17.11 min) and early (n=9, mean time: 5.22 min) control groups based on the criteria of 10 min of contrast leakage period. No significant between-group differences regarding clinical outcomes were observed after IPR (p=1). In our series, all patients with IPR were controlled with further coil packing or stenting without proximal balloon occlusion within 31 min of contrast leakage. There was no difference in clinical outcomes when the long contrast leakage period group and short contrast leakage period group were compared.

Raising Systemic Blood Pressure to Delay Irreversible Intestinal Ischemia in a Swine Model of Proximal Superior Mesenteric Artery Occlusion

IntroductionAcute proximal superior mesenteric artery (SMA) occlusion is highly lethal, and adjuncts are needed to mitigate ischemic injury until definitive therapy. We hypothesized that raising mean arterial pressure (MAP) >90 mmHg with norepinephrine may delay irreversible bowel ischemia by increasing gastroduodenal artery (GDA) flow despite possible pressor-induced vasospasm. Methods12 anesthetized swine underwent laparotomy, GDA flow probe placement, and proximal SMA exposure and clamping. Animals were randomized between conventional therapy (CT) versus targeted MAP >90 mmHg (MAP push; MP) where norepinephrine was titrated after 45 min of SMA occlusion. Animals were followed until bowel death or 4 h. Kaplan–Meier bowel survival, mean normalized GDA flow, and histology were compared. Results12 swine (mean 57.8 ± 7.6 kgs) were included, six per group. Baseline weight, HR, MAP and GDA flows were not different. Within 5 min following SMA clamping, all 12 animals had an increase in MAP without other intervention from 81.7 to 105.5 mmHg (29.1%, P < 0.01) with a concomitant 74.9% increase in GDA flow as compared to baseline (P < 0.01). Beyond 45 min postclamp, MAP was greater in the MP group as intended, as were GDA flows. Median time to irreversibly ischemic bowel was 31% longer for MAP push animals (CT: 178 versus MP: 233 min, P = 0.006), Hazard Ratio of CT 8.85 (95% CI: 1.86-42.06); 3/6 MP animals versus 0/6 CT animals with bowel survived to predetermined end point. ConclusionsIn this swine model of acute complete proximal SMA occlusion, increasing MAP >90 mmHg with norepinephrine was associated with an increase in macrovascular blood flow through the GDA and bowel survival. Norepinephrine was not associated with worse bowel survival and a MAP push may increase the time window where ischemic bowel can be salvaged.

Predictors of devastating functional outcome despite successful basilar thrombectomy.

Basilar thrombosis frequently leads to poor functional outcomes, even with good endovascular reperfusion. We studied factors associated with severe disability or death in basilar thrombectomy patients achieving revascularization. We retrospectively analyzed records from a health system's code stroke registry, including successful basilar thrombectomy patients from January 2017 to May 2023 who were evaluated with pretreatment computed tomography perfusion. The primary outcome was devastating functional outcome (90-day modified Rankin Scale [mRS] score 5-6). A multivariable logistic regression model was constructed to determine independent predictors of the primary outcome. The area under the receiver operator characteristics curve (AUC) was calculated for the model distinguishing good from devastating outcome. Among 64 included subjects, with mean (standard deviation) age 65.6 (14.1) years and median (interquartile range) National Institutes of Health Stroke Scale (NIHSS) 18 (5.75-24.5), the primary outcome occurred in 28 of 64 (43.8%) subjects. Presenting NIHSS (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.01-1.14, p = 0.02), initial glucose (OR 0.99, 95% CI 0.97-1.00, p < 0.05), and proximal occlusion site (OR 7.38, 95% CI 1.84-29.60, p < 0.01) were independently associated with 90-day mRS 5-6. The AUC for the multivariable model distinguishing outcomes was 0.81 (95% CI 0.70-0.92). We have identified presenting stroke severity, lower glucose, and proximal basilar occlusion as predictors of devastating neurological outcome in successful basilar thrombectomy patients. These factors may be used in medical decision making or for patient selection in future clinical trials.

Evaluation of effectiveness and safety of the large-format pRESET 6-50 thrombectomy stent-retriever in the endovascular treatment of ischemic stroke: real-world experiences from two tertiary comprehensive stroke centers.

Mechanical thrombectomy (MT) has become the standard treatment for acute ischemic stroke (AIS) with large vessel occlusion (LVO). First-pass (FP) reperfusion of the occluded vessel and fewer passes with stent retrievers show improvement in functional outcomes in stroke patients, while higher numbers of passes are associated with higher complication rates and worse outcomes. Studies indicate that a larger size of the stent-retriever is associated with a higher rate of first-pass reperfusion and improved clinical outcomes. In this retrospective study, we investigated the clinical performance of a recently developed and one of the largest stent-retrievers available in the treatment of LVO (pRESET 6-50, phenox GmbH, Bochum). All consecutive patients with ischemic stroke due to proximal large vessel occlusion treated with MT using the pRESET 6-50 stent-retriever in two tertiary stroke centers between 09/2021 and 07/2022 were included in this study. The reperfusion rate after MT was quantified by the modified thrombolysis in cerebral infarction (mTICI) score, and functional neurological outcome was evaluated with the National Institutes of Health Stroke Scale (NIHSS) score and the major early neurological recovery (mENR) rate after 24 h. Successful FP reperfusion was defined as mTICI ≥ 2b. Successful and complete reperfusion were defined as mTICI ≥ 2b and mTICI ≥ 2c, respectively. In total, 98 patients (52 men and 46 women) with a median age of 75 (range 25-95 years) were included. A total of 70 (72%) patients presented with an occlusion of the middle cerebral artery (MCA) in the M1 segment, 6 (6%) patients with an occlusion of the M2 segment, 17 (17%) patients with an occlusion of the internal carotid artery (ICA), and 5 (5%) patients with an occlusion of the obstructed basilar artery (BA). Successful FP reperfusion was achieved in 58 patients (62%). Successful and complete reperfusion were achieved in 95 (97%) and 82 (83%) patients, respectively. The median National Institutes of Health Stroke Scale (NIHSS) in all treated patients improved from 17 to 7.5. Major early neurological recovery (mENR) was observed in 34 patients (35.1%). MT with the pRESET 6-50 stent-retriever achieves high successful first-pass and final reperfusion rates in patients with AIS and LVO. The results of this study support the thesis to use large-format stent-retriever in proximal vessel occlusion MT whenever feasible in order to improve high FP and final reperfusion rate, which are known predictors of good clinical outcome.

Clinical efficacy of permanent internal mammary artery occlusion in chronic coronary artery disease: a double-blind, randomized, sham-controlled trial

Abstract Introduction Natural internal mammary artery (IMA) bypasses to the coronary circulation have been shown to act as extracardiac sources of myocardial blood supply, which has been found augmented by right IMA device occlusion. The goal of this randomized, sham-controlled trial was to test the efficacy of permanent right or left IMA device occlusion on symptoms of chronic coronary artery disease (CAD), on coronary artery occlusive blood supply, as well as on myocardial ischemia. Methods This was a prospective superiority trial in 100 patients with chronic CAD randomly allocated (1:1) to IMA permanent vascular device occlusion (verum group) or to IMA sham intervention (placebo group). The primary study endpoint was the change in treadmill exercise time (DET in seconds, s) during 6 weeks of follow-up after trial intervention. Secondary study endpoints were the changes in simultaneously obtained collateral flow index (CFI), and angina pectoris during a 1-minute proximal balloon occlusion of the coronary artery of interest. CFI is the ratio between simultaneous mean coronary occlusive divided by mean aortic pressure both subtracted by central venous pressure. Results In the verum and placebo group, exercise time changed from 398±176s to from 421±198s in the verum group (p=0.1745), and from 426±162s to 430±166s in the placebo group (p=0.55); DET was +23±116s and +4±120s, respectively (p=0.44). CFI change during follow-up was +0.022±0.061 in the verum and -0.039±0.072 in the placebo group (p&amp;lt;0.0001). Angina pectoris at follow-up during the coronary balloon occlusion for CFI measurement had decreased or disappeared in 20/48 patients of the verum group, and in 10/47 patients of the placebo group (p=0.0336). Conclusion Permanent IMA device occlusion tends to augment treadmill exercise time in response to heightened coronary artery occlusive blood supply, the fact of which is reflected by mitigated signs of myocardial ischemia.

Abstract 12780: Impact of Target Vessel on the Procedural Techniques and Outcomes of Chronic Total Occlusion Percutaneous Coronary Intervention

Introduction: There is limited information on the impact of the target vessel on the procedural techniques and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Methods: We analyzed the baseline clinical and angiographic characteristics and procedural outcomes of 11,580 CTO PCIs performed between 2012 and 2022 at 44 centers. Results: The most common CTO target vessel was the right coronary artery (RCA) (53.1%) followed by the left anterior descending artery (LAD) (26.0%) and the left circumflex artery (LCX) (19.8%). RCA CTO lesions were longer and more complex with higher J-CTO score compared with LAD or LCX CTO lesions. Technical success was higher among LAD (88.8%) lesions when compared with RCA (85.7%) or LCX (85.8%) lesions (p&lt;0.001). The incidence of major adverse cardiovascular events (MACE) was overall 1.9% (n=220) and was similar among target vessels (p=0.916). There was a tendency towards more frequent utilization of the retrograde approach for more proximal occlusions in all three target vessels. When compared with all other RCA lesions combined, distal RCA lesions had higher technical success (87.7% vs. 85.3%; p=0.048). Technical success was similar between various locations of LAD CTOs (p=0.704). First/second/third obtuse marginal branch had lower technical success when compared with all other LCX lesion locations (82.7% vs. 86.8%; p=0.014). There was no association between MACE and CTO location in all three target vessels. Conclusions: LAD CTO PCIs had higher technical and procedural success rates among target vessels. The incidence of MACE was similar among target vessels, and also among various locations within the target vessel.

Abstract 14730: The Effect of Electronic Cigarette Exposure With Nicotine on Expression of Inflammatory Genes and Blood Parameters in a Chronic Myocardial Infarction Model

Background: There are no data available regarding the effects of chronic electronic cigarette (eC) exposure on inflammatory gene expressions after myocardial infarction (MI) and whether eC could alter blood counts and chemistries in this setting. We determined the effect of eC on expression of genes for inflammatory cytokines and receptors and blood parameters during the healing phase of MI. Methods and Results: Sprague Dawley rats of either sex were subjected to a proximal left coronary artery occlusion to induce a large anterior wall MI. At 1 week, rats were randomized to exposure to air or E-cig with nicotine (eC Nic + ) for 12 weeks. After 12 weeks of exposure, rat inflammatory cytokine and receptor PCR array was performed (n=4 in each group). The data showed 70 out of 84 inflammatory-related genes were downregulated in the eC Nic+ group versus the air group and 11 downregulated genes reached a significant difference. Interleukin 6 (IL6), Tumor necrosis factor superfamily (TNF), Chemokine (C-C motif) ligand 12 (Ccl12), and C-X-C Motif Chemokine Receptor 3 (Cxcr3) gene expressions were significantly decreased by -6.49 fold, p=0.0048, -2.63 fold, p=0.0227, -2.71 fold, p=0.0146, and -2.28 fold, p=0.0067, respectively, in the eC Nic+ group vs air group. The rats in eC Nic+ group had significantly decreased white blood cell (WBC), lymphocyte and platelet count compared to the air group (Figure). Conclusions: Exposure to eC Nic+ alters the expression of inflammatory genes and decreases blood immune cells during the healing phase of MI. Our findings suggest that chronic inhalation of e-cigarette aerosols can suppress the immune and inflammatory response in the already compromised setting of MI.

Abstract 12538: Myocardial Bridge Induced Cardiomyopathy

Introduction: A myocardial bridge(MB) is a condition in which the epicardial coronary artery traverses through the myocardium, has an intra-myocardial course of varying length, and then exits the myocardium and appears on the surface of the heart. Clinical Presentation: A 54-year-old male with no significant past medical history except tobacco abuse and anxiety presented to the hospital with retrosternal chest pain radiating to the back and shoulder and associated with nausea and diaphoresis. His SBP was 100/60, and his heart rate 46. His EKG showed ST elevation in inferior leads, and he was given a nitro tablet, which improved the chest pain to 5/10. He was emergently taken to the Cath lab and found to have proximal left circumflex artery occlusion and underwent PCI with a 2.25x23 Xience Drug-eluting stent. Troponin was elevated to 2.35. His cath also showed a significant mid-LAD myocardial bridge. His echocardiogram showed mid and apical anterior, anterior septal, apical wall, and inferior wall hypokinesis. His EF has been reduced to 30%. Coronary CTA showed mid-LAD has myocardial bridging, which is more than 2 cm long and 5 mm deep in the muscle. The patient has persistently low HR in 40-45, beta-blocker was not started. Due to significant cardiomyopathy induced by a myocardial bridge, unroofing of LAD was done off-pump. His EF improved to 55% after three months of surgery. Discussion: CABG or myotomy is the treatment of choice for patients with symptomatic myocardial bridging refractory to medical therapy, evidence of myocardial ischemia or infarction, or &gt;75% systolic coronary compression on angiography. Incidental myocardial bridging finding without ischemia or symptoms does not require any treatment. Symptomatic patients with ischemia on stress tests can be offered beta or calcium channel blockers. Medical therapy is superior to revascularization with percutaneous intervention.

Feasibility and Clinical Outcome Predictors of Mechanical Thrombectomy in Distal Arterial Occlusion Causing Acute Ischemic Stroke: A Monocentric Retrospective Study.

The feasibility and clinical outcome predictors of mechanical thrombectomy (MT) for strokes caused by distal arterial occlusion (DAO) remain the subject of debate. A retrospective analysis was conducted of patients with consecutive acute ischemic stroke treated using MT. Clinical and procedural-associated factors were studied to compare the efficacy, safety, and short-term and long-term outcomes of MT between the proximal arterial occlusion (PAO) and DAO groups. The predictors of a good functional outcome in the DAO group were also identified. A total of 116 patients were included in this study, of whom 23 (19.8%) underwent MT for DAO. A higher complete recanalization rate was independently associated with PAO in adjusted models [adjusted odds ratio, 0.596; 95% CI, 0.377-0.941]. The measures of safety and clinical outcome showed no significant differences between the DAO and PAO groups. The National Institute of Health stroke scale (NIHSS) score on admission, hybrid technique use, and complete recanalization rate emerged as independent predictors of a good functional outcome in the DAO group. The efficacy, safety, and short-term and long-term outcomes of DAO thrombectomy were similar to those of PAO thrombectomy. The good functional outcome predictors of MT in DAO included NIHSS on admission, hybrid technique use, and complete recanalization. Overall, the findings lead us to propose that MT may be considered a feasible option for treating DAO after a careful risk-benefit analysis.

Abstract 13361: The Effect of Electronic Cigarette Exposure on Flow Mediated Vasodilation and LV Remodeling in a Chronic Myocardial Infarction Model

Introduction: There is little information about the effect of electronic cigarette (e-C) exposure on the cardiovascular system in the setting of myocardial infarction (MI) and whether e-C’s could alter vascular or cardiac function during the healing phase of MI. We determine the effect of e-C on endothelial function, cardiac remodeling and function during the healing phase of MI. Methods: Sprague Dawley rats (both sexes) were anesthetized and subjected to a proximal left coronary artery occlusion to induce a large anterior wall MI. At one week, rats were randomized to receive either 12 weeks of exposure to purified air (n=37) or e-cig vapor plus 15 mg/ml of nicotine (e-Cn=32). At 12 weeks endothelial function was tested by assessing femoral artery diameter and blood flow following a 5- minute femoral artery occlusion and reperfusion (ultrasound and flow probe). Cardiac function was assessed by echocardiography; remodeling was also assessed by quantitative histologic analysis. Results: Baseline blood flow in the femoral artery did not differ between groups, but peak reperfusion blood flow was blunted in the e-Cn group (1.59 ± 0.15 ml/min) vs. the air group (2.11 ± 0.18 ml/min; p=0.034). Femoral artery diameter after reperfusion was narrower in the e-Cn group (0.54 ± 0.02mm) compared to the air group (0.60 ± 0.02mm; p=0.023). Postmortem left ventricular (LV) volumes were similar in the e-Cn (0.69 ± 0.04 ml) and air groups (0.73 ± 0.04 ml; p=NS); and myocardial infarct expansion index did not differ between groups (1.4 ± 0.1 in e-Cn group versus 1.3 ± 0.1 in air group; p=NS). Gross pathology LV wall thickness was greater in the e-Cn group (1.38 ± 0.12 mm) versus the air group (1.04 ± 0.10 mm) despite no increase in blood pressure at 12 weeks in the e-CN group. LV fractional shortening by echo did not differ between groups at 12 weeks (e-Cn at 29 ± 2% and air at 27 ± 1%; p=NS). Conclusion: Exposure to e-Cn during the healing phase of MI was associated with altered endothelial function with reduced femoral artery blood flow and diameter at reperfusion, but not with worsened LV dilation or worsened cardiac function. E-Cn did increase gross pathologic LV wall thickness. E-Cn exposure during the healing phase of MI has deleterious effects on the CV system but does not dilate the LV.

Abstract 19069: Empagliflozin Improves Right Ventricular Remodeling and Right Ventricular Systolic Function in Non-Diabetic Hfref: Insights From Porcine and Human Studies

Background On top of improving heart failure outcomes, we and others have demonstrated that SGLT2 inhibitors induce reverse cardiac remodeling in HFrEF. However, these studies have focused on the left ventricle, while no information is available on the potential benefits of SGLT2i on the right ventricle (RV). Therefore, our objective is to investigate the effect of empagliflozin on RV remodeling and RV systolic function in non-diabetic HFrEF Methods Animal study: HFrEF was induced by means of proximal LAD occlusions for 2 hours in non-diabetic pigs. Pigs were then randomized to empagliflozin 10mg daily or placebo for 2 months (8/group). Pigs were evaluated with cardiac MRI. We previously reported that empagliflozin reduces LV volumes and improve LVEF (Santos-Gallego, JACC 2019) Human study : The EMPATROPISM clinical trial ((NCT03485222) randomized non-diabetic HFrEF patients to empagliflozin 10mg daily or placebo. All patients were evaluated with MRI. We previously reported that empagliflozin reduces LV volumes, while also improving peakVO2, LVEF, and quality of life (Santos-Gallego, JACC 2021) Results Animal study: Both groups were similar at baseline (RVESV 16.1±3.2 vs 15.8±2.1mL; RVEF 51.9±5.6 vs 52.7±4.7%; p=NS). Cardiac MRI showed that empagliflozin-treated pigs exhibited smaller RVEDV and RVESV at 2 months compared with control. Also treated animals exhibited better RVEF and better right ventriculoarterial coupling (Ees/Ea) vs control (Table) Human study: Both groups were similar at baseline (RVESV 87.4±35.6 vs 76.4±32.4 mL; RVEF 47.1±7.9 vs 49.2±9.1%; p=NS). Cardiac MRI showed that empagliflozin-treated patients experienced a reduction in RVESV vs placebo. Furthermore, empagliflozin-treated patients exhibited improvement in RVEF and in right ventriculoarterial coupling (Ees/Ea) vs control (Table) Conclusions Empagliflozin improves right ventricular remodeling and right ventricular systolic function in non-diabetic HFrEF