Background: The complexity of left atrial appendage (LAA) in patients with nonvalvular atrial fibrillation (NVAF) is closely related to LAA thrombosis and stroke incidence. But the classification of LAA morphology is not uniform and controversial. Hypothesis: This study divided the LAA into two categories according to the LAA morphology to investigate the risk of thrombosis related to the LAA structural complexity in NVAF patients. Methods: A total of 336 NVAF patients were enrolled continuously in this study. The patients were divided into thrombosis group and non-thrombosis group according to whether the thrombus presence in LAA. Through computer LAA three-dimensional reconstruction, LAA morphology was divided into the complex type and simple type according to with or without the clearly lobulated structure judged by imaging experts. The relationship between LAA thrombosis and various potential risk factors was analyzed. Results: A total of 19 potential risk factors for LAA thrombosis in NVAF patients were enrolled into statistical analysis. The coincidence rate of LAA morphology classification was 96.4% (324/336) between two imaging experts. Multivariate logistic regression analysis showed that complex LAA morphology (OR 4.168, 95% CI 1.871-9.288, P < .001) was associated with the presence of LAA thrombus, independently of other enrolled risks. Conclusions: It is a concise and reliable method to divide the LAA morphology into complex type and simple type according to whether with the clearly lobulated structure. The complex LAA is an independent risk factor for LAA thrombosis in NVAF patients. K E Y W O R D S left atrial appendage, thrombosis, nonvalvular atrial fibrillation, risk factor Jionghong He and Zenan Fu contributed equally to the study. [Correction added on June 19, 2020, after first online publication: Some of the analysis results have been updated. See Appendix S1 for correction details.]

Background Percutaneous coronary intervention (PCI) of heavily calcified lesions (HCLs) is associated with higher complication rates and worse clinical outcomes. Cutting balloon (CB) has been widely used for HCLs, but patients’ prognosis had not been fully clarified. The study aimed to compare 3-year clinical outcomes between patients with HCLs that are treated with CBs and those with non-HCLs. Method Patients who underwent PCI in Guizhou Provincial People’s Hospital from June 2015 to September 2018 were retrospectively included. HCL was defined as radiopaque and high-pressure undilatable lesions. CBs were routinely used in combination with non-compliant balloons for the HCLs. Major adverse cardiac event (MACE) and target vessel failure (TVF) were assessed at 3-year follow-up. Result Among 2432 patients included in the study, 210(8.6%) had HCLs with a procedural success rate of 91.0%. The patients with HCLs had a higher incidence of MACE (23.3% vs. 10.8%, P < 0.001) than those with non-HCLs. By propensity score matching, 172 patients with HCLs were 1:1 paired to those with non-HCLs, and their PCI vessels were exactly matched. The MACE and TVF were significantly higher in the patients with HCLs than those with non-HCLs (MACE: 21.5% vs. 13.4%, P = 0.036; TVF: 19.8% vs. 9.9%, P = 0.008). In the Cox regression analysis, HCL is independently associated with higher risks of MACE [HR: 1.72(1.01–2.94), P = 0.047], TVF [HR: 2.10(1.15–3.81), P = 0.015] and repeat revascularization [HR: 2.20(1.07–4.52), P = 0.032]. Conclusion Patients with HCLs undergoing PCI using CBs in combination with non-compliant balloons had higher risks of complications, procedural failure, and worse clinical outcomes at 3 years than those with non-HCLs.

BackgroundCardiac computed tomography (CCT) is an emerging non-invasive modality for assessing left atrial appendage (LAA) thrombus, but the results were conflicting. Our study aims to evaluate the accuracy of CCT for detecting LAA thrombus in patients undergoing catheter ablation of atrial fibrillation (AF), using transesophageal echocardiography (TEE) as the reference standard.MethodsFrom May 2017 to December 2022, 726 patients (male: 60.2%, age: 61±11 years) who had both TEE and CCT before catheter ablation of AF were retrospectively included. The CCT protocol consisted of one angiographic phase and one delayed scan 30 seconds later. LAA thrombi were defined as solid masses on TEE or persistent defects on CCT. The thrombus dimension and location, the LAA filling and emptying flow velocity were assessed by TEE.ResultsOf the 57(7.9%) patients with LAA thrombi identified by TEE, 29(50.9%) were located at the LAA ostium, and 28(49.1%) were in the LAA. The former showed higher motility following blood flow and heartbeats than the latter. The CCT detected 14(48.3%) of the LAA-ostium thrombi but 25(89.3%) of those in the LAA (p= 0.001). The LAA-ostium thrombi with the LAA mean flow velocity higher than 0.35m/s and maximum diameters shorter than 10mm were more prone to have CCT false-negative results.ConclusionFor patients undergoing catheter ablation for AF, CCT with a 30s delay scan is less sensitive to LAA thrombi than TEE, especially LAA-ostium thrombi with smaller sizes and higher LAA flow velocity.Clinical perspective sectionWhat are new?Over half of the LAA thrombi were located at the LAA ostium.The CCT was less sensitive to the LAA-ostium thrombi with smaller sizes and higher LAA flow velocity.What is the clinical implication?1. The CCT using a 30s delay scan did not reliably exclude the LAA thrombi for the patients scheduled for pulmonary vein isolation, especially those located at the LAA ostium.

Background The origin distribution of right-ventricular-outflow-tract (RVOT) ventricular arrhythmias (VAs) remains unclear. There is limited data on the ablation effectiveness of the reversed U-curve method compared with the antegrade method. Objectives To investigate the origin distribution of RVOT-type VAs and compare the ablation effectiveness of the two methods. Method Consecutive patients who had idiopathic RVOT-type VAs were prospectively enrolled. After activation mapping, patients were randomly assigned to supravalvular strategy using the reversed U-curve or subvalvular strategy using the antegrade method. The primary outcome was initial ablation (IA) success, defining as the successful ablation within the first three attempts. Results 61 patients were enrolled from November 2018 to June 2020. Activation mapping revealed 34/61 (55.7%) of the earliest ventricular activating (EVA) sites were above the pulmonary valves (PVs). The IA success rate was 25/33(75.8%) in the patients assigned to supravalvular strategy as compared with 16/28(57.1%) in those assigned to subvalvular strategy (P=0.172). Logistic regression revealed a substantial and qualitative interaction between the EVA sites and IA strategies (Pinteraction<0.001). For multiple-comparison, either strategy had a remarkably higher IA success rate in treating its ipsilateral EVA sites than contralateral ones (P<0.0083). Conclusion Of the idiopathic RVOT-type VA origins, half were located above the PV. The two strategies did not differ in the primary outcomes. However, they complement locating the EVA sites and facilitate ipsilateral ablation, which produces a significantly higher IA success rate. (Chinese Clinical Trial Registry number, ChiCTR2000029331)

As the rate of percutaneous coronary intervention increases, in-stent restenosis (ISR) has become a burden. Random forest (RF) could be superior to logistic regression (LR) for predicting ISR due to its robustness. We developed an RF model and compared its performance with the LR one for predicting ISR. We retrospectively included 1501 patients (age: 64.0 ± 10.3; male: 76.7%; ISR events: 279) who underwent coronary angiography at 9 to 18 months after implantation of 2nd generation drug-eluting stents. The data were randomly split into a pair of train and test datasets for model development and validation with 50 repeats. The predictive performance was assessed by the area under the curve (AUC) of the receiver operating characteristic (ROC). The RF models predicted ISR with larger AUC-ROCs of 0.829 ± 0.025 compared to 0.784 ± 0.027 of the LR models. The difference was statistically significant in 29 of the 50 repeats. The RF and LR models had similar sensitivity using the same cutoff threshold, but the specificity was significantly higher in the RF models, reducing 25% of the false positives. By removing the high leverage outliers, the LR models had comparable AUC-ROC to the RF models. Compared to the LR, the RF was more robust and significantly improved the performance for predicting ISR. It could cost-effectively identify patients with high ISR risk and help the clinical decision of coronary stenting.