Apostolos Tzikas

1. Atrial fibrillation (AF) is the most common sustained arrhythmia and a major cause of ischemic stroke, systemic embolism, disability and death [1]. Oral anticoagulation (OAC), preferentially wit...

Since its introduction in 2002, left atrial appendage closure (LAAC) has rapidly expanded as an alternative to anticoagulation in patients with atrial fibrillation at high risk of stroke. Harmonized processes for data collection, analysis, and reporting in LAAC trials are essential to enhance research quality and improve clinical practice. The Left Atrial Appendage Academic Research Consortium (LAARC) initiative is an independent collaboration of academic research organizations, cardiology and neurology experts, clinical trialists, and regulatory authorities from the USA, Europe, and Asia. The consortium engaged clinical experts, regulators—including the US Food and Drug Administration (FDA), European Notified Bodies, and Japan’s Pharmaceuticals and Medical Devices Agency (PMDA)—and industry leaders to define standardized study elements and endpoints for LAAC trials. Key considerations included alignment with prior Academic Research Consortium initiatives, procedural and mechanistic insights, and clinical relevance. Consensus definitions were proposed for mortality, stroke, bleeding, and device performance, along with composite endpoints for safety and effectiveness. The proposed LAARC consensus definitions aim to standardize endpoint reporting, improve comparability across studies, and support regulatory and clinical trial applications for this evolving therapy through broad dissemination in the peer-reviewed literature.

Aims: Left atrial appendage closure (LAAC) has emerged as an alternative to oral anticoagulation (OAC) for stroke prevention in atrial fibrillation (AF), but its long-term comparative efficacy remains uncertain. This systematic review and meta-analysis evaluated randomized controlled trials (RCTs) comparing LAAC with OAC in AF. Methods and results: MEDLINE, Embase, Scopus, and the Cochrane Database of Systematic Reviews were searched through 8 April 2026. Risk ratios (RR) with 95% confidence intervals (CI) were pooled using random-effects models. Certainty of evidence (CoE) was assessed using GRADE. Six RCTs involving 7004 participants were included (3681 assigned to LAAC and 3323 to OAC). Compared with OAC, LAAC resulted in a significantly higher risk of ischaemic stroke or systemic embolism (134 vs. 80 events; RR 1.41, 95% CI 1.07–1.86; moderate CoE). No significant differences were observed for any stroke or systemic embolism (RR 1.10, 95% CI 0.87–1.39; moderate CoE), all-cause mortality (RR 0.92, 95% CI 0.77–1.10; high CoE), cardiovascular mortality (RR 0.90, 95% CI 0.67–1.21; moderate CoE), non-cardiovascular mortality (RR 0.92, 95% CI 0.75–1.12; moderate CoE), major bleeding (RR 0.91, 95% CI 0.77–1.08; high CoE), or haemorrhagic stroke (RR 0.58, 95% CI 0.28–1.17; moderate CoE). LAAC reduced the risk of nonprocedural clinically relevant bleeding compared with OAC (RR 0.50, 95% CI 0.43–0.59; high CoE). Conclusion: In patients with AF, LAAC results in a higher risk of ischaemic stroke or systemic embolism than an OAC-based strategy. Compared with OAC, LAAC has no effect on major bleeding or mortality and does not reduce haemorrhagic stroke.

Background: Transcatheter aortic valve implantation (TAVI) continues to expand rapidly, with over 100 000 procedures now performed annually in Europe. This growth highlights the need to optimize patient selection and procedural workflows to ensure quality and cost-effective care. Aims: The Second European TAVI Pathway Study aimed to describe current TAVI practices across Europe and assess changes since the 2022 edition. Methods and results: Between January and May 2025, TAVI operators from 42 European countries were invited to complete an online survey concerning their centre’s current practice. Responses were received from 202 centres in 37 different countries, performing 44 089 TAVI procedures in 2024 (mean 218 per centre; interquartile range [IQR] 99–284). Dedicated Heart Valve Clinics are present in 54%, and supportive staff in 52%. Most centres (81%) use a Heart Team approach, with age thresholds for TAVI typically set at ≥75 (64%) or ≥80 (26%) years. On-site cardiac surgery is available in 96% of participating centres. Local anaesthesia alone (33%) or with conscious sedation (63%) is the most common for routine transfemoral TAVI. Secondary radial access (70%) and left ventricular wire pacing (59%) have increased from 48% and 43% in 2022, respectively. Early mobilization (≤8 hours) is routine in 63% of cases, and early discharge (≤2 days) rose from 43% in 2022 to 51% in 2024. However, the proportion of centres reporting waiting times >3 months increased from 19% to 26%. Conclusion: Minimalist TAVI approaches are widely adopted across Europe, with increasing rates of early discharge. However, extended waiting times remain a significant challenge.

BACKGROUND Catheter ablation for paroxysmal atrial flutter (PAFL) and atrial fibrillation (PAF) is a first-line treatment to maintain sinus rhythm. However, routine preprocedural imaging is not standardized, despite a high prevalence of incidental findings that may influence procedural planning. This report describes a case of a bronchial arteriovenous malformation (BAVM) detected on multidetector computed tomography prior to ablation in a patient with PAFL and PAF. CASE REPORT A 69-year-old woman who predominantly experienced episodes of PAFL, with occasional PAF, underwent pre-ablation multidetector computed tomography. Imaging demonstrated a serpiginous bronchial artery draining into the right pulmonary artery, with 2 aneurysms (approximately 1 cm proximal to the aortic origin and 4 cm proximal to the drainage site) in close proximity to the right pulmonary veins. Hemodynamic evaluation confirmed a non-significant left-to-right shunt, and a conservative approach was selected. Because of perioperative concerns about the BAVM's location, the procedural plan was modified; rather than a combined procedure of pulmonary vein isolation with right isthmus ablation, only a typical PAFL ablation was performed. The patient had an uneventful post-procedural course, without arrhythmic recurrence or BAVM-related complications at 6 months. Annual follow-ups with contrast-enhanced computed tomography angiography were scheduled after joint cardiology and radiology consultation. CONCLUSIONS This case highlights the importance of systematic preprocedural imaging in PAF and PAFL ablation to detect unexpected intra- or extracardiac findings, such as a BAVM, that may affect procedural strategy and require a multidisciplinary approach.

Aims: The optimal short-term antithrombotic strategy following left atrial appendage occlusion (LAAO) remains uncertain, with the need to balance thromboembolic prevention and bleeding risk presenting a critical challenge. Recent evidence suggests that direct oral anticoagulants (DOACs) may provide a favourable safety–efficacy profile, with low-dose regimens showing potential benefits during the device endothelialization period. This network meta-analysis (NMA) aimed to compare the efficacy and safety of various antithrombotic strategies, including DOAC dosing, following LAAO. Methods and results: A systematic review and NMA were conducted following Cochrane and PRISMA guidelines. Eligible studies included randomized controlled trials (RCT) and observational studies comparing at least two antithrombotic regimens in patients with non-valvular atrial fibrillation undergoing percutaneous LAAO. Primary outcomes were major bleeding and thromboembolism. Secondary outcomes included device-related thrombosis (DRT) and all-cause mortality. Pairwise and network meta-analyses were performed using a random-effects model. A total of 52 studies (49 observational and 3 RCTs) involving 69 751 patients were included. DOACs were consistently associated with significantly lower rates of major bleeding and all-cause mortality than other antithrombotic regimens. Low-dose DOACs showed a potential advantage over standard-dose DOACs in reducing major bleeding risk (odds ratio 0.45, 95% confidence interval: 0.22–0.92). For thromboembolism and DRT, standard-dose DOAC significantly reduced risk compared with single antiplatelet therapy (SAPT) but not with dual antiplatelet therapy (DAPT), whereas low-dose DOAC significantly reduced both outcomes compared with SAPT, DAPT, and vitamin K antagonists plus SAPT. In ranking analysis, DOACs emerged as the most effective and safest antithrombotic strategy, with low-dose DOACs demonstrating further safety benefits in bleeding outcomes. Conclusion: DOACs provide a superior safety–efficacy profile compared with other antithrombotic strategies following LAAO, significantly reducing the risks of major bleeding, thromboembolic events, and mortality. While low-dose DOACs may offer additional bleeding risk reduction without compromising efficacy, further research is warranted to confirm their role in clinical practice.

Heart failure with preserved ejection fraction (HFpEF) remains a major clinical challenge due to its heterogeneous presentation and limited therapeutic options. Accurate patient phenotyping is essential to improve diagnosis, prognostication, and treatment personalization. Machine learning (ML) has emerged as a powerful tool to identify clinically meaningful HFpEF subgroups by integrating diverse data sources, including clinical, imaging, biomarker, and physiological parameters. ML-based models can uncover subtle patterns not captured by traditional methods, offering improved risk stratification, earlier intervention, and guidance toward individualized therapy. Future progress will rely on standardized data collection, validation across populations, and incorporation into clinical decision support systems. Advancements in explainable artificial intelligence, federated learning, and multi-omics integration are expected to further refine phenotyping strategies and translate into improved patient outcomes. Continued interdisciplinary collaboration is essential to unlock the full potential of ML in transforming HFpEF management.

In most patients with atrial fibrillation, effective stroke prevention necessitates long-term (often lifelong) oral anticoagulant therapy (OAC). However, the effectiveness of OAC therapy in a clinical setting (i.e., outside the controlled environment of randomized clinical trials) is strongly influenced by patients’ adherence and persistence with prescribed therapy. However, suboptimal adherence to OAC remains a substantial problem in routine practice - available evidence suggests that patients do not take their OAC one out of every four days, and approximately one in three to four patients is poorly adherent to OAC. In addition, around 15% of high-risk OAC-eligible patients with AF refuse to take OAC for a variety of patient-specific reasons. Poor adherence to OAC therapy is associated with adverse clinical outcomes (such as stroke or systemic embolism, hospitalization, mortality, bleeding [particularly with Vitamin K antagonist therapy]) and increased economic costs. In this overview, we summarize important aspects of the adherence to medication concept, including the definition and measurement of adherence, the determinants and prevalence of OAC non-adherence, the clinical importance of achieving and maintaining good adherence, strategies to improve adherence to OAC, and alternative treatment options for effective thromboprophylaxis in patients with AF who are non-adherent to OAC therapy.