Daily Cardiology Research Analysis

BACKGROUND: Cardiac amyloidosis (CA) is an under-recognized cause of left-ventricular hypertrophy (LVH) that is often misclassified as hypertrophic cardiomyopathy (HCM) or hypertensive heart disease (HHD). We aimed to develop and externally validate an AI model using electrocardiograms (ECG) and echocardiography to distinguish CA from other LVH aetiologies. METHODS: A retrospective, multicenter study was conducted, with a derivation cohort collected from PUMCH (290 CA patients, 215 HCM patients, and 160 HHD patients) and an external validation cohort recruited from 10 other hospitals across China (126 CA patients, 240 HCM patients, and 190 HHD patients). Twenty-eight clinical, ECG, and echocardiographic predictors were included, and we selected the top 7 important features by recursive feature elimination strategy. The Super Learner model combines predictions from 11 machine learning models, and model performance was evaluated via macro-AUC, accuracy, precision, F1 score, and etc. We developed a simplified scoring system to diagnose CA, and classifying patients into three groups based on CA probability to minimize misdiagnosis risk. RESULTS: Ranking by feature importance, the top seven features were included and used for model construction, including Sokolow-Lyon index, interventricular septal thickness, systolic blood pressure, left-ventricular posterior wall thickness, tricuspid annular plane systolic excursion, average E/e', and left-ventricular ejection fraction. The Super Learner model, combining Extra Trees, Histogram-based Gradient Boosting, LightGBM, and Multi-Layer Perceptron, achieved the highest AUC of 0.97 (95% confidence interval [CI]: 0.95-0.98). In external validation, the super learner model achieved AUCs of 0.96 (95% CI: 0.95-0.98) for CA, 0.93 (0.91-0.95) for HCM, and 0.91 (0.89-0.94) for HHD. And the simplified scoring system also showed robust diagnostic performance (AUC 0.90, 95% CI 0.86-0.93). CONCLUSIONS: We developed an AI model integrating ECG and echocardiography that provides a clinically applicable and noninvasive framework for CA screening and diagnosis, and implementation through a WeChat-based screening program. However, its performance and generalizability should be further validated in larger prospective multicenter studies.

BACKGROUND: After guideline-recommended dual antiplatelet therapy (DAPT) following percutaneous coronary intervention (PCI), long-term antiplatelet monotherapy is advised, but the optimal agent in real-world practice remains uncertain. OBJECTIVES: The authors aimed to compare efficacy and safety of clopidogrel versus aspirin monotherapy in stable post-PCI patients. METHODS: Using the Korean nationwide claims and health examination database, we identified PCI-treated patients maintained on clopidogrel or aspirin monotherapy between 2009 and 2019. The co-primary outcomes were major adverse cardiovascular events (a composite of cardiovascular death, myocardial infarction or ischemic stroke) and major bleeding. RESULTS: Among 133,454 patients receiving DAPT, 67,652 (50.7%) continued with clopidogrel monotherapy and 65,802 (49.3%) continued with aspirin monotherapy. The median durations of DAPT and monotherapy duration were 1.0 year (IQR: 0.8-1.2) and 3.3 years (IQR: 1.3-6.2), respectively. After stabilized inverse probability of treatment weighting, clopidogrel monotherapy was associated with lower risks of major adverse cardiovascular events (HR: 0.759; 95% CI: 0.733-0.785; P < 0.0001) and major bleeding (HR: 0.895; 95% CI: 0.848-0.945; P < 0.0001) compared with aspirin monotherapy. Clopidogrel monotherapy was associated with lower risks of cardiovascular death (HR: 0.605; 95% CI: 0.573-0.638; P < 0.0001), myocardial infarction (HR: 0.921; 95% CI: 0.877-0.968; P = 0.0011), and ischemic stroke (HR: 0.674; 95% CI: 0.624-0.729; P < 0.0001) than aspirin monotherapy. The treatment effects were consistent across prespecified subgroups and DAPT durations. CONCLUSIONS: In the stable post-PCI period, clopidogrel monotherapy may be preferred over aspirin monotherapy for long-term prevention due to its efficacy and safety.

BACKGROUND: Pulsed field ablation (PFA) is an increasingly used energy source to treat patients with atrial fibrillation (AF). Although nonthermal ablation seems to result in a safety benefit, adverse events occurring after PFA are not well studied. OBJECTIVES: The aim of this study was to report life-threatening ischemic and arrhythmic adverse events (AEs) occurring after PFA of AF. METHODS: A case series and systematic literature review were conducted, including patients with AF who experienced ischemic AEs with delayed onset or arrhythmic AEs after PFA energy delivery between March 2023 and January 2026. Events were classified as 1) delayed and/or recurrent ST-segment elevation; 2) ventricular arrhythmia (VA); or (3) sudden cardiac death. RESULTS: A total of 39 patients (30 from literature review and 9 newly published extended case series [9 of 5,963 procedures (0.15%)]) were included (mean age 67 ± 10 years, 72% men, 72% with persistent AF, 51% with coronary artery disease). Seventeen patients presented with delayed ST-segment elevation at a median of 16 minutes (Q1-Q3: 4-315 minutes) after last PF delivery, of whom 11 (65%) subsequently developed VA and 2 died (12%). Among the 13 patients with available 12-lead electrocardiograms, ST-segment elevation was observed in the inferior leads (n = 10 [77%]), anteroseptal leads (n = 1 [8%]), or both (n = 2 [15%]). VA occurred in another 6 patients and sudden cardiac death in 16 patients at a median of 6 days (Q1-Q3: 2-18 days) after PFA. CONCLUSIONS: Rare but life-threatening ischemic and malignant arrhythmic AEs associated with PFA underscore the need for structured surveillance and standardized reporting. A deeper understanding of the underlying mechanisms will be essential to identify patients at risk and guide future studies aimed at further improving the safety of PFA.