Optical coherence tomography analysis of lesion characteristics and thrombus types in non ST-segment elevation myocardial infarction patients.

The precise features of lesions in non-ST-segment elevation myocardial infarction (NSTEMI) patients with total occlusion (TO) of the infarct-related artery (IRA) are still unclear. This study employs optical coherence tomography (OCT) to investigate pathological features in NSTEMI patients with or without IRA TO and explores the relationship between thrombus types and IRA occlusive status. This was a single-center retrospective study. A total of 202 patients diagnosed with NSTEMI were divided into two groups: those with Thrombolysis In Myocardial Infarction (TIMI) flow grade 0 before percutaneous coronary intervention (PCI) (referred to as the TO group, n = 100) and those TIMI flow grade 1-3 (referred to as the Non-TO group, n = 102). Baseline characteristics, coronary angiography findings, and OCT results were collected. Multivariate logistic analysis identified factors influencing TO in NSTEMI. The category of NSTEMI was further subdivided based on the type of electrocardiogram (ECG) into two subgroups: ST segment unoffset myocardial infarction (STUMI) and ST segment depression myocardial infarction (STDMI). This division allows for a more specific classification of NSTEMI cases. The TO group had a younger age, higher male representation, more smokers, lower hypertension and cerebrovascular disease incidence, lower left ventricular ejection fraction (LVEF), and higher creatine kinase myocardial band (CKMB) and creatine kinase (CK) peak levels. In the TO group, LCX served as the main IRA (52.0%), whereas in the Non-TO group, LAD was the predominant IRA (45.1%). Compared to the Non-TO group, OCT findings demonstrated that red thrombus/mixed thrombus was more common in the TO group, along with a lower occurrence of white thrombus (p < 0.001). The TO group exhibited a higher prevalence of STUMI (p = 0.001), whereas STDMI was more commonly observed in the Non-TO group (p = 0.001). NSTEMI presents as STUMI and STDMI distinct entities. Red thrombus/mixed thrombus in IRA often indicates occlusive lesions with STUMI on ECG. White thrombus suggests non-occlusive lesions with STDMI on ECG.

Evaluation of an Optimized Workflow for the Radiofrequency Catheter Ablation of Paroxysmal Atrial Fibrillation.

BACKGROUND A significant number of atrial fibrillation (AF) recurrences occur after initial ablation, often due to pulmonary vein reconnections or triggers from non-pulmonary veins. MATERIAL AND METHODS Patients with paroxysmal AF who underwent radiofrequency catheter ablation for the first time were enrolled. Base on propensity score matching (1: 1 matching), 118 patients were selected for an optimized workflow for the radiofrequency catheter ablation of paroxysmal AF (OWCA) group and a conventional group. Comparative analysis of the acute and 12-month clinical outcomes was conducted. Moreover, an artificial intelligence analytics platform was used to evaluate the quality of pulmonary vein isolation (PVI) circles. RESULTS PVI was successfully achieved in all patients. Incidence of first-pass isolation of bilateral PVI circles was higher (P=0.009) and acute pulmonary vein reconnections was lower (P=0.027) in the OWCA group than conventional group. The OWCA group displayed a significant reduction in the number of fractured points (P<0.001), stacked points (P=0.003), and a greater proportion of cases in which the radiofrequency index achieved the target value (P=0.003). Additionally, the contact force consistently met the force over time criteria (P<0.001) for bilateral PVI circles in the OWCA group, accompanied by a shorter operation time (P=0.017). During the 12-month follow-up period, the OWCA group exhibited a higher atrial arrhythmia-free survival rate following the initial ablation procedure than did the conventional group. CONCLUSIONS The optimized workflow for radiofrequency catheter ablation of paroxysmal AF could play a crucial role in creating higher quality PVI circles. This improvement is reflected in a significantly elevated 12-month atrial arrhythmia-free survival rate.

A novel stepwise catheter ablation method of the mitral isthmus for persistent atrial fibrillation: efficacy and reproducibility.

BACKGROUND: Ethanol infusion of the vein of Marshall (EI-VOM) has been widely used to facilitate mitral isthmus (MI) ablation. According to the literature, the success rate of achieving a bidirectional conduction block across the MI ranges from 51 to 96%, with no standardized strategy or method available for cardiac electrophysiologists. OBJECTIVES: This study aimed to introduce and evaluate a novel ablation method of MI. METHODS: Consecutive patients with persistent atrial fibrillation (PeAF) that underwent catheter ablation were included. The MI ablation procedure followed a stepwise approach. In step 1, ethanol infusion of the vein of Marshall (EI-VOM) was performed. In step 2, a "V-shape" endocardial linear ablation connecting the left inferior pulmonary vein (LIPV) to mitral annulus (MA) was performed. In step 3, earliest activation sites(EASs) near the ablation line were identified using activation mapping followed by reinforced ablation. In step 4, precise epicardial ablation was performed, with the catheter introduced into the coronary sinus(CS) to target key ablation targets (KATs). RESULTS: 135 patients with PeAF underwent catheter ablation with the stepwise ablation method adopted in 119 cases. Bidirectional conduction blocks were achieved in 117 patients (98.3%). The block rates of every step were 0%, 58.0%, 44.0%, and 92.9%, and the cumulative block rates for the four steps were 0%, 58.0%, 76.5%, and 98.3%, respectively. No patient experienced fatal complications. CONCLUSIONS: Our novel stepwise catheter ablation method for MI yielded a high bidirectional block rate with high reproducibility.

The ratio of QRS/RV6-V1: a new electrocardiographic predictor of short- and long-term adverse clinical outcomes in patients with acute myocardial infarction combined with new-onset right bundle branch block.

Background: A few studies have focused on electrocardiography (ECG) parameters correlating with clinical prognosis in patients with acute myocardial infarction (AMI) combined with new-onset right bundle branch block (RBBB). Objective: To assess the prognostic value of a new ECG parameter, namely, the ratio of QRS duration/RV6-V1 interval (QRS/RV6-V1), in patients with AMI combined with new-onset RBBB. Materials and methods: A total of 272 AMI patients combined with new-onset RBBB who received primary percutaneous coronary intervention (P-PCI) were retrospectively enrolled in the study. First, the patients were divided into survival group and non-survival group. Demographic, angiographic, and ECG characteristics were compared between the two groups. Receiver operating characteristic (ROC) curve was used to screen the best ECG parameter for predicting 1-year mortality. Second, the ratio of QRS/RV6-V1, a continuous variable, was converted to the high ratio group and low ratio group according to the optimal cutoff value point determined by the X-tile software. We compared the patient's demographic, angiographic, and ECG characteristics, in-hospital major adverse cardiovascular events (MACE), and 1-year mortality between the two groups. Multivariate logistic and Cox regressions were used to evaluate whether the ratio of QRS/RV6-V1 was an independent prognostic factor of in-hospital MACE and 1-year mortality. Results: The ROC curve showed that the ratio of QRS/RV6-V1 had a higher value for predicting in-hospital MACE and 1-year mortality than the QRS duration, RV6-V1 interval, and RV1 interval. The patients in the high ratio group had significantly higher CK-MB peak and Killip class, lower ejection fraction (EF%), higher ratio of the left anterior (LAD) descending artery as infarct-related artery (IRA), and longer total ischemia time (TIT) than those in the low ratio group. The QRS duration was wider in the high ratio group than that in the low ratio group, whereas RV6-V1 was narrower in the high ratio group compared with that in the low ratio group. The in-hospital MACE rate (93.3% vs. 31.0%, p < 0.001) and 1-year mortality rate (86.7% vs. 13.2%, p < 0.001) in the high ratio group were higher than those in the low ratio group. The higher ratio of QRS/RV6-V1 was an independent predictor of in-hospital MACE (odds ratio, 8.55; 95% CI, 1.40-52.37; p = 0.02) after adjusting other confounders. Cox regression showed that the higher ratio of QRS/RV6-V1 predicted higher 1-year mortality of the patients with AMI combined with new-onset RBBB [hazard ratios (HR), 12.4; 95% CI, 7.26-21.22); p < 0.001] than the lower ratio of QRS/RV6-V1, and the HR still stayed at 2.21 even after a multivariable adjustment (HR, 2.21; 95% CI, 1.05-4.64); p = 0.037). Conclusion: According to the results of our study, the high ratio of QRS/RV6-V1 (>3.0) was a valuable predictor of short- and long-term adverse clinical outcomes in AMI patients combined with new-onset RBBB. The implications of the high ratio of QRS/RV6-V1 were severe ischemia and pseudo synchronization between bi-ventricle.

Ablation index-guided high-power ablation for superior vena cava isolation in patients with atrial fibrillation.

Background: The strategy of ablation index (AI)-guided high-power ablation seems to be a novel strategy for performing pulmonary vein isolation (PVI). An AI-guided high-power ablation strategy was used in this study to determine whether superior vena cava isolation (SVCI) after PVI was feasible and safe for patients with AF. Methods: Data from 53 patients with AF were collected. Mapping and ablation of SVC were performed. The applied power was set at 45 W and the procedure was guided by AI. The SVC was divided into six segments in a cranial view. The RF applications and AI values in different segments were compared and analyzed. Using receiver operating characteristic (ROC) analysis, the diagnostic accuracy of AI value for predicting segment block was evaluated. Results: Electrical SVCIs were successfully achieved in all patients. SVCI was performed by segment ablation in most cases, with RF applications in different segments. The mean AI value in non-lateral walls was higher than that of the lateral wall (392 ± 28 vs. 371 ± 37, P < 0.001). Acutely blocked sites had significantly larger AI values compared with no-blocked sites (390 ± 30 vs. 343 ± 23, P < 0.001). The optimal AI cut-off value for non-lateral segments was 379 (sensitivity: 75.9%, specificity: 100%) and for lateral segments was 345 (sensitivity: 82.3%, specificity: 100%). Conclusion: The AI values were predictive of the acute conduction block of SVCI. With AI values of 345 and 379, respectively, conduction block was achieved in the lateral walls at a lower level than in the non-lateral walls.

The Differences in Clinical Characteristic and Outcomes of New Onset Typical versus Atypical Right Branch Bundle Block in Acute Myocardial Infarction.

Objective: The purpose of this study is to explore the clinical characteristics and estimate the new-onset atypical right branch bundle block (ATRBBB) predictive value in short-term and long-term mortality by comparing the typical right branch bundle block (TRBBB) subset in acute myocardial infarction (AMI) patients. Methods: A total of 224 AMI patients combined with new onset RBBB who received primary coronary angiography were included, being admitted to Henan Provincial People's Hospital in China from July 2010 to June 2021. Patients were divided into typical RBBB group (n = 104) and atypical RBBB group (n = 120). The differences in clinical characteristics between the two groups were analyzed. Logistic and Cox regression analysis were performed to identify independent predictors of in-hospital Major Adverse Cardiovascular Events (MACE). Result: The ATRBBB group had a higher proportion of smoking and alcohol consumption, higher body mass index, worse cardiac function (killip ≧ II proportion), higher peak value of CK-MB, lower LVEF%, longer total ischemia time, higher proportion of LAD (left anterior descending coronary artery) occlusion, and multivessel lesions, compared to the TRBBB group. The ATRBBB group had a higher proportion of in-hospital MACE and 1-year all-cause mortality compared to the TRBBB group. ATRBBB was an independent predictor of in-hospital MACE and 1-year mortality in patients with AMI combined with new onset RBBB. Conclusions: ATRBBB group had more serious clinical symptoms and clinical prognosis. New ATRBBB is an independent predictor of in-hospital MACE and 1-year death in patients with AMI combined with RBBB. If the infarct-related vessel was opened immediately, the evolution of TRBBB to ATRBBB may be avoided, leading to a better prognosis.

Relationship Between an Ischaemic J Wave Pattern and Ventricular Fibrillation in ST-Elevation Myocardial Infarction Patients.

BACKGROUND: This study determined the ischaemic J wave pattern associated with ventricular fibrillation (VF). METHODS: A total of 262 patients diagnosed with ST-elevation myocardial infarction (STEMI) were recruited from October 2017 to September 2020. All data were collected and analysed, including baseline characteristics, electrocardiogram (ECG), coronary angiography (CAG), and examination outcomes. RESULTS: There were 193 STEMI patients with J wave elevation but without an ischaemic J wave (NJ group) and 69 patients with an ischaemic J wave; the latter were then subgrouped into early repolarization pattern (ERP; n=62) and Brugada pattern groups (BrP [anteroseptal ERP]; n=7). Univariate and multivariate logistic regression analyses were used to clarify high-risk factors and characteristics of ischaemic J waves. Multivariate logistic regression analysis revealed that an ischaemic J wave (odds ratio [OR], 9.708; 95% CI, 2.570-36.664; P=0.01) independently predicted VF. In the subgroup analysis, BrP (OR, 31.214; 95% CI, 3.949-246.742; P=0.001), slur morphology of the ERP (OR, 8.15; 95% CI, 1.563-42.558; P<0.05), and the number of leads with an ischaemic J wave > 3 (OR, 16.174; 95% CI, 3.064-85.375; P=0.001) were significantly associated with VF occurrence after adjusting for multiple variables. CONCLUSION: An ischaemic J wave is an independent risk factor for VF in STEMI patients. BrP, slur morphology, and > 3 leads with an ischaemic J wave could increase the incidence of VF.

Comparison of higher-power and conventional power ablation of atrial fibrillation using contact force-sensing catheters: a systematic review and meta-analysis.

BACKGROUND: Contact force-sensing catheters have been widely used in catheter ablation. During the past few decades, more attention has been paid on the technique of high-power ablation. The purpose of this meta-analysis is to compare the efficacy and safety of conventional power and high power on atrial fibrillation radiofrequency ablation by contact force-sensing catheters. METHODS: We identified studies through searching MEDLINE, Embase, the Web of Science, Scopus, and the Cochrane Library from inception up until July 2020. The primary outcomes were defined as recurrence of atrial tachyarrhythmia and complications. The secondary outcomes were acute reconnections of pulmonary veins (PVs), ablation time, and the total procedural time. RESULTS: Four nonrandomized, observational studies (nROS) were selected involving 231 patients with high-power ablation and 239 patients with conventional power ablation. There were insignificant differences in the recurrence rate of atrial tachyarrhythmia (14.2% versus 20.5%, OR: 0.64, 95%CI: 0.39 to 1.04, Z = 1.82, P = 0.07) and clinical complications (1.7% versus 2.5%, OR: 0.72, 95%CI: 0.21 to 2.47, Z = 0.51, P = 0.61) between high-power and conventional power ablation. However, compared with conventional power group, the high-power group had fewer acute PVs reconnections (P = 0.0001), shorter in ablation time (P < 0.0001), and the total procedural time (P < 0.0001). CONCLUSIONS: High-power ablation could not only ablate safely and efficiently but also reduce focal ablation time and total procedural time significantly.