Half-dose ticagrelor versus standard-dose clopidogrel in a dual antiplatelet regimen for stent-assisted coiling or flow diversion of unruptured intracranial aneurysms: a cohort study.

BACKGROUND: Intracranial hemorrhage is the major safety concern of standard-dose ticagrelor (90 mg twice daily) based dual antiplatelet therapy (DAPT). The bleeding avoidance strategy through dose de-escalation has been investigated in interventional cardiology. However, the preserved antithrombotic efficacy and better safety of half-dose (45 mg twice daily) ticagrelor remains unverified in patients undergoing stent-assist coiling (SAC) or flow diversion (FD) treating unruptured intracranial aneurysms (UIA). METHODS: A single-center, prospective, cohort study was conducted to compare DAPT with aspirin 100 mg daily plus half-dose ticagrelor vs standard-dose clopidogrel (75 mg daily) in UIA patients. The adenosine diphosphate inhibition (ADPi) rate was utilized to quantify the antagonization of adenosine diphosphate (ADP)-induced platelet aggregation. The patients were followed-up at 6 month after discharge. The primary efficacy outcome was the major adverse cardiovascular and cerebrovascular events (MACCE), and the primary safety outcome was major bleeding. The secondary outcome was minor hemorrhage. RESULTS: Our study included 322 UIA patients, of which 254 patients were eventually enrolled after propensity score matching. The ADPi of half-dose ticagrelor (51.56%±31.46%) was comparable (P=0.089) to that of clopidogrel (57.44%±22.76%). The outcomes were also comparable. Five (3.94%) patients in the ticagrelor group and eight (6.30%) patients in the clopidogrel group reported MACCE (P=0.393). One patient in the ticagrelor group was diagnosed with asymptomatic intracranial hemorrhage 1 month after stenting. There were 36 (28.35%) minor hemorrhagic events in the ticagrelor group and 35 (27.56%) in the clopidogrel group, (P=0.889). CONCLUSION: Half-dose ticagrelor was effective and safe as a potential alternative to clopidogrel in the DAPT regimen for patients undergoing SAC/FD for UIA.

Machine Learning to Dynamically Predict In-Hospital Venous Thromboembolism After Inguinal Hernia Surgery: Results From the CHAT-1 Study.

BACKGROUND: The accuracy of current prediction tools for venous thromboembolism (VTE) events following hernia surgery remains insufficient for individualized patient management strategies. To address this issue, we have developed a machine learning (ML)-based model to dynamically predict in-hospital VTE in Chinese patients after hernia surgery. METHODS: ML models for the prediction of postoperative VTE were trained on a cohort of 11 305 adult patients with hernia from the CHAT-1 trial, which included patients across 58 institutions in China. In data processing, data imputation was conducted using random forest (RF) algorithm, and balanced sampling was done by adaptive synthetic sampling algorithm. Data were split into a training cohort (80%) and internal validation cohort (20%) prior to oversampling. Clinical features available pre-operatively and postoperatively were separately selected using the Sequence Forward Selection algorithm. Nine-candidate ML models were applied to the pre-operative and combined datasets, and their performance was evaluated using various metrics, including area under the receiver operating characteristic curve (AUROC). Model interpretations were generated using importance scores, which were calculated by transforming model features into scaled variables and representing them in radar plots. RESULTS: The modeling cohort included 2856 patients, divided into 2536 cases for derivation and 320 cases for validation. Eleven pre-operative variables and 15 combined variables were explored as predictors related to in-hospital VTE. Acceptable-performing models for pre-operative data had an AUROC ≥ 0.60, including logistic regression, support vector machine with linear kernel (SVM_Linear), attentive interpretable Tabular learning (TabNet), and RF. For combined data, logistic regression, SVM_Linear, and TabNet had better performance, with an AUROC ≥ 0.65 for each model. Based on these models, 7 pre-operative predictors and 10 combined predictors were depicted in radar plots. CONCLUSIONS: A ML-based approach for the identification of in-hospital VTE events after hernia surgery is feasible. TabNet showed acceptable performance, and might be useful to guide clinical decision making and VTE prevention. Further validated study will strengthen this finding.

Ticagrelor versus Clopidogrel in the Dual Antiplatelet Regimen for Unruptured Intracranial Aneurysm Treated with Stent-Assisted Coil Embolization: A Single-Center Cohort Study.

BACKGROUND: Dual antiplatelet therapy (DAPT) of aspirin plus clopidogrel is commonly used in patients with unruptured intracranial aneurysms treated with stent-assisted coil (SAC) embolization. However, the unpredictable clopidogrel efficacy of the 5%-55% nonresponders limits its use. Ticagrelor, as a potential alternative of clopidogrel, is an antiplatelet agent with low resistance rates but uncertain efficacy and safety in these patients. METHODS: A single-center cohort study was performed to compare the efficacy and safety of ticagrelor with clopidogrel in the DAPT regimen in patients with unruptured intracranial aneurysms and treated with SAC. The patients with clopidogrel resistance identified as inadequate adenosine diphosphate inhibition rate determined by thromboelastography were treated with ticagrelor instead, and both drugs achieved adequate suppression of platelet aggregation when stents were implanted. The occurrence of major adverse cardiovascular and cerebrovascular events (MACCE) and bleeding events was recorded through 6 months follow-up. RESULTS: Data from 86 patients with 99 unruptured intracranial aneurysms and treated by SAC with clopidogrel were compared with those from 108 patients with 111 aneurysms and treated with ticagrelor. Neither the baseline characteristics nor the incidence of the MACCE or bleeding events differed between the groups. Ticagrelor exerted significantly higher adenosine diphosphate inhibition rate than that of the clopidogrel. Multivariable logistic regression analysis showed that the incidence of MACCE was related to hematocrit and fibrinogen levels. CONCLUSIONS: Ticagrelor seemed to be as effective and safe as clopidogrel for SAC in unruptured intracranial aneurysms. Hematocrit and fibrinogen levels were independent risk factors for the incidence of MACCE.