Absent hyperdense middle cerebral artery sign is associated with poor functional outcome after mechanical thrombectomy.

BACKGROUND: The hyperdense middle cerebral artery sign on computed tomography indicates proximal middle cerebral artery occlusion. Recent reports suggest an association between the hyperdense sign and successful reperfusion. The prognostic value of the hyperdense middle cerebral artery sign in patients receiving mechanical thrombectomy has not been extensively studied. AIMS: Our study aims to evaluate the association between the hyperdense middle cerebral artery sign and functional outcome in patients with M1 occlusions that had undergone mechanical thrombectomy. METHODS: We conducted a single-center retrospective observational cohort study of 102 consecutive patients presenting with acute M1 occlusions that had undergone mechanical thrombectomy. Patients were stratified into cohorts based on the presence of hyperdense middle cerebral artery sign visually assessed on computed tomography by two readers. The outcomes of interests were functional disability measured by the ordinal Modified Rankin Scale (mRS) at 90 days, mortality, reperfusion status and hemorrhagic conversion. RESULTS: Out of the 102 patients with M1 occlusions, 71 had hyperdense middle cerebral artery sign. There was no significant difference between the cohorts in age, baseline mRS, NIHSS, ASPECTS, and time to reperfusion. The absence of hyperdense middle cerebral artery sign was associated with increased odds of being dependent or dying (higher mRS) (OR: 3.24, 95% CI: 1.30-8.06, p = 0.011) after adjusting for other significant predictors, including age, female sex, hypertension, presenting serum glucose, ASPECTS, CTA collateral score, and successful reperfusion. CONCLUSION: The absence of hyperdense middle cerebral artery sign is associated with worse functional outcome in patients presenting with M1 occlusions undergoing thrombectomy.

Quantitative Assessment of Hyperdense Sign Measured by Hounsfield Units is Associated with Unsuccessful Mechanical Thrombectomy.

PURPOSE: Despite advancement in mechanical thrombectomy (MT) techniques, 10-30% of MT for large vessel occlusions (LVO) are unsuccessful. Current prediction models fail to address the association between patient-specific factors and reperfusion. We aimed to evaluate objective, easily reproducible, admission clinical and radiological biomarkers that predict unsuccessful MT. METHODS: We analyzed consecutive anterior LVO MT patients at two comprehensive stroke centers. The primary outcome was unsuccessful reperfusion defined by a modified thrombolysis in cerebral infarction (mTICI) score of 0-2a. We quantitatively assessed the hyperdense vessel sign by measuring Hounsfield units (HU) on admission computed tomography (CT). Receiver operating characteristic (ROC) curves were plotted to estimate the predictive value of quantitative hyperdense middle cerebral artery (MCA) measurements (delta and ratio) and of the final model for mTICI scores. We performed multivariable logistic regression to analyze associations with outcomes. RESULTS: Out of 348 patients 87 had unsuccessful MT. Smoking, difficult arch, vessel tortuosity, vessel calcification, diminutive vessels, truncal M1 occlusion, delta HU and HU ratio were significantly associated with unsuccessful MT in the univariate analysis. When we fitted two separate multivariate models including all significant variables and a HU measurement; delta HU <6 (odds ratio, OR = 2.07, 95% confidence intervals, CI 1.09-3.92) and HU ratio ≤1.1 (OR = 2.003, 95% CI 1.05-3.81) were independently associated with failed MT after adjustment for smoking, diminutive vessels, vessel tortuosity, and difficult arch. The area under the curve AUC<9 of the final model was 0.717. CONCLUSION: Novel radiological biomarkers on CT, CT angiography (CTA) and digital subtraction angiography (DSA) may help identify patients refractory to standard MT and prepare interventionalists for using additional alternative methods. Quantitative assessment of HU (delta and ratio) may be important in developing objective prediction tools for unsuccessful MT.

Ventricular Tachycardia (VT) Substrate Characteristics: Insights from Multimodality Structural and Functional Imaging of the VT Substrate Using Cardiac MRI Scar, 123I-Metaiodobenzylguanidine SPECT Innervation, and Bipolar Voltage.

Postischemic adaptation results in characteristic myocardial structural and functional changes in the ventricular tachycardia (VT) substrate. The aim of this study was to compare myocardial structural and functional adaptations (late gadolinium enhancement/abnormal innervation) with detailed VT mapping data to identify regional heterogeneities in postischemic changes. Methods: Fifteen patients with ischemic cardiomyopathy and drug-refractory VT underwent late gadolinium enhancement cardiac MRI (CMR), 123I-metaiodobenzylguanidine SPECT, and high-resolution bipolar voltage mapping to assess fibrosis (>3 SDs), abnormal innervation (<50% tracer uptake), and low-voltage area (<1.5 mV), respectively. Three-dimensional reconstructed CMR/123I-metaiodobenzylguanidine models were coregistered for further comparison. Results: Postischemic structural and functional adaptations in all 3 categories were similar in size (reported as median [quartile 1-quartile 3]: CMR scar, 46.1 cm2 [33.1-86.9 cm2]; abnormal innervation, 47.8 cm2 [40.5-68.1 cm2]; and low-voltage area, 29.5 cm2 [24.5-102.6 cm2]; P > 0.05). However, any single modality underestimated the total VT substrate area defined as abnormal in at least 1 of the 3 modalities (76.0 cm2 [57.9-143.2 cm2]; P < 0.001). Within the total VT substrate area, regions abnormal in all 3 modalities were most common (25.2%). However, significant parts of the VT substrate had undergone heterogeneous adaptation (abnormal in <3 modalities); the most common categories were "abnormal innervation only" (18.2%), "CMR scar plus abnormal innervation only" (14.9%), and "CMR scar only" (14.6%). All 14 VT channel/exit sites (0.88 ± 0.74 mV) were localized to myocardium demonstrating CMR scar and abnormal innervation. This specific tissue category accounted for 68.3% of the CMR scar and 31.2% of the total abnormal postischemic VT substrate area. Conclusion: Structural and functional imaging demonstrated regional heterogeneities in the postischemic VT substrate not appreciated by any single modality alone. The coexistence of abnormal innervation and CMR scar may identify a particularly "proarrhythmic" adaptation and may represent a potential novel target for VT ablation.

Early Results of a Novel Mitral Valve Repair Procedure: The Interpapillary Polytetrafluoroethylene Bridge Formation.

BACKGROUND: Surgical repair of ischemic mitral regurgitation (IMR) associated with chordal rupture in patients with ischemic cardiomyopathy is challenging as it aims to correct several structural pathologies at once. There are ongoing studies evaluating multiple approaches, however long term results are still scarce. METHODS AND RESULTS: 19 patients with IMR underwent mitral valve repair with interpapillary polytetrafluoroethylene (PTFE) bridge and neochordae formation at the Zala County Teaching Hospital. Concomitant coronary artery bypass grafting was performed in all patients. Post-procedural Transesophageal Echocardiogram (TEE) showed no mitral regurgitation (MR) in eighteen (94.7%) patients, with a leaflet coaptation mean height of 8 ± 3 mm. No operative mortality was observed. At the follow up (mean 17.7 ± 4.6 months; range 9 to 24 months), 17 (89%) patients showed no leakage and 2 had regurgitation grade ≤1, with documented NYHA functional class I or II in all patients. CONCLUSION: This retrospective study presents the first results of a novel surgical approach to treating ischemic mitral regurgitation. The interpapillary PTFE bridge formation is a safe and feasible surgical procedure that is reproducible, time sparing and effectively eliminates mitral valve regurgitation with promising long-term results.