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Siontis, Konstantinos C

0000-0002-6658-0971

Mayo Clinic

Department of Cardiovascular Medicine, Mayo Clinic Rochester, MN, US.

Citations 22

Mitral Annular Disjunction: Separating the Wheat from the Chaff
Sabbag, Avi , Siontis, Konstantinos C , Sabbag, Avi , Siontis, Konstantinos C.

Arrhythmia & Electrophysiology Review | April 17, 2026 | Volume: No volume available | Issue: No issue available | Pages: No page available

10.15420/aer.2025.96 Get It

Multimorbidity in Atrial Fibrillation: Impact on Outcomes
Manemann, Sheila M., Alonso, Alvaro, Noseworthy, Peter A. , Siontis, Konstantinos C., Gersh, Bernard J., Roger, Veronique L., Ryu, Euijung , Killian, Jill M. , Weston, Susan A., Vaughan, Lisa E. , Gersh, Bernard J. , Alonso, Álvaro , Alonso, Alvaro , Siontis, Konstantinos C , Gersh, Bernard J , Roger, Veronique L , Chamberlain, Alanna M , Noseworthy, Peter A , Vaughan, Lisa , Siontis, Konstantinos C. , Roger, Véronique L. , Chamberlain, Alanna M.

Journal of the American Heart Association | February 24, 2026 | Volume: 15 | Issue: 5 | Pages: No page available

10.1161/jaha.124.040612 Get It

Background Multimorbidity is common in patients with atrial fibrillation (AF); however, the impact of the number and type of comorbid conditions on outcomes remains uncertain. Methods This cohort study included patients with new‐onset AF from a Midwest region between 2013 and 2017. Eighteen chronic conditions at the time of AF were classified into groups: cardiometabolic, other somatic, and mental health. Cox regression determined associations between the number of each condition type with death, ischemic stroke/transient ischemic attack, and congestive heart failure, stratified by age. Results Among 16 509 patients with AF (mean age, 74 years; 43% women), the mean number of cardiometabolic, other somatic, and mental health conditions was 2.7, 1.4, and 0.5, respectively. The number and type of conditions had a varying impact on outcomes and differed by age. A higher number of cardiometabolic conditions were associated with increased risk of death within 90 days only in people aged ≥85 years (≥4 conditions versus 0: hazard ratio [HR], 1.74 [95% CI, 1.05–2.87]), whereas for death after 90 days, associations were strongest in the youngest age group (<65 years: HR, 1.83 [95% CI, 1.35–2.46]; 65–74 years: HR, 1.34 [95% CI, 1.04–1.73]; 75–84 years: HR, 1.32 [95% CI, 1.09–1.60]; ≥85 years: HR, 1.14 [95% CI, 0.96–1.35]). Associations with outcomes were generally strongest in the youngest age group and attenuated with older age for higher number of other somatic conditions, whereas the pattern was less consistent for mental health conditions. Conclusions Along with cardiometabolic‐related conditions, other somatic and mental health conditions are important predictors of outcomes in AF, with effects differing by age, and should be considered when caring for these patients.
Safety and efficacy of intracardiac echocardiography in atrial fibrillation ablation: a meta-analysis
Karakasis, Paschalis , Tzeis, Stylianos , Pamporis, Konstantinos , Vlachos, Konstantinos , Siontis, Konstantinos C, Antoniadis, Antonios P , Bénali, Karim , Theofilis, Panagiotis null, Tsiachris, Dimitris , Chun, Julian, Jaïs, Pierre , Fragakis, Nikolaos, Karakasis, Paschalis , Pamporis, Konstantinos , Antoniadis, Antonios P. , Siontis, Konstantinos C , Theofilis, Panagiotis , Tsiachris, Dimitrios , Chun, Julian K R , Fragakis, Nikolaos , Tzeis, Stylianos , Siontis, Konstantinos C. , Benali, Karim , Jaı̈s, Pierre

Europace | January 8, 2026 | Volume: 28 | Issue: 2 | Pages: No page available

10.1093/europace/euag002 Get It

Abstract Aims Intracardiac echocardiography (ICE) is increasingly incorporated into atrial fibrillation (AF) ablation workflows, enabling real-time anatomic guidance and procedural precision. Nevertheless, ICE utilization shows substantial geographic variability, and its clinical benefit remains incompletely understood. This meta-analysis evaluated the efficacy, safety, and procedural performance of ICE-guided vs. non-ICE-guided AF ablation. Methods and results MEDLINE, the Cochrane Library, and Scopus were systematically searched through 3 August 2025. Three reviewers independently performed study selection, data extraction, and risk-of-bias assessment. Random-effects models were used to pool data from 44 AF ablation studies comprising 482 043 patients. ICE guidance was associated with lower odds of any complication (OR 0.69; 95% CI 0.53–0.89), including significant reductions in cardiac tamponade (OR 0.58; 95% CI 0.53–0.62) and mortality (OR 0.21; 95% CI 0.16–0.27). ICE-guided ablation was also associated with shorter total procedure and fluoroscopy times, reduced radiation exposure, and lower contrast agent utilization. Atrial tachyarrhythmia (AT) recurrence did not differ between groups (OR 0.92; 95% CI 0.79–1.06). However, ICE use was associated with higher odds of first-pass pulmonary vein isolation (OR 1.62; 95% CI 1.09–2.41) and successful isolation of all pulmonary veins at the end of the procedure (OR 2.12; 95% CI 1.37–3.27), and lower odds of repeat ablation (OR 0.65; 95% CI 0.59–0.72). Conclusion ICE-guided AF ablation is associated with superior procedural safety and efficiency and a similar risk of AT recurrence compared to non-ICE-guided approaches.
Dose-Dependent Effects of Radiation on the Coronary Arteries: Results From a Preclinical Model of Single-Fraction Proton Beam Cardiac Radioablation
Hirao, Tatsuhiko , Rettmann, Maryam E. , Deisher, A., Newman, Laura K. , Gades, Naomi M. , Lerman, Amir, Asirvatham, Samuel J., Kruse, Jon J. , Merrell, Kenneth W., Shumway, Dean A. , Packer, Douglas L. , Siontis, Konstantinos C., Lerman, Amir , Asirvatham, Samuel J. , Merrell, Kenneth W. , Deisher, Amanda J, Koya, Taro , Newman, Laura K , Gades, Naomi M , Lerman, Amir , Asirvatham, Samuel J , Kruse, Jon J , Merrell, Kenneth W , Shumway, Dean A , Packer, Douglas L , Siontis, Konstantinos C , Siontis, Konstantinos C.

Circulation: Arrhythmia and Electrophysiology | December 25, 2025 | Volume: 19 | Issue: 1 | Pages: No page available

10.1161/circep.125.013995 Get It

BACKGROUND: Cardiac radioablation is emerging as a treatment modality for refractory ventricular tachycardia. This study aimed to evaluate the effects of radiation on the coronary arteries in a swine model of proton beam cardiac radioablation. METHODS: Eighteen swine underwent single-fraction 30 to 40 Gy pencil-beam scanning proton therapy targeting the left ventricle and were euthanized 12 to 40 weeks later. Treatment planning was performed without restricting the dose to the coronary arteries. The maximum point dose (D max ) to the epicardial coronary arteries was calculated. In secondary analyses, the mean (D mean ) and minimum dose received by the highest irradiated 0.01 cm 3 (D 0.01 ) of each coronary artery were also calculated. Coronary artery segments were harvested from the D max sites for histological analysis, and the D max was correlated with stenosis severity. RESULTS: Ninety-six coronary arteries were analyzed. No stenoses were observed by computed tomography imaging preirradiation. By histological analysis posteuthanasia, 25/96 (26%) coronaries sampled at their D max sites had ≥75% stenosis. The median D max was 4.7 Gy for the <75% stenosis group and 29.7 Gy for the ≥75% stenosis group ( P <0.001). The AUC-ROC for the association between D max and stenosis ≥75% was 92.2%. A D max value of 20.1 Gy best predicted stenosis ≥75%, with sensitivity 92.3% and specificity 87.1%. The AUC-ROCs for the associations of D mean and D 0.01 with stenosis ≥75% were 84.8% and 91.6%, respectively. In histopathologic analysis, intimal hyperplasia was the most common coronary artery abnormality at the D max sites, and it was present in 61.5% of all arteries and in 93.9% of arteries with D max ≥20 Gy. CONCLUSIONS: In this preclinical model of proton beam cardiac radioablation, coronary stenoses occurred in a dose-dependent manner, with D max showing the closest correlation with stenosis ≥75%. These data provide for the first time a framework for dose constraint considerations for the coronary arteries during treatment planning for cardiac radioablation and thoracic malignancy radiation.
Impact of Timing of Atrial Fibrillation Ablation on AF Recurrence and Clinical Outcomes in Patients With HFpEF and HFrEF
Eisa, Mahmoud , Elbenawi, Hossam , Iftikhar, Momina, Shaer, Ahmed El , Eltony, Muhammad , Almaadawy, Omar , Aglan, Amro , Mohamed, Kareem A., Shadi, Mahmoud , Rao, Ch. Mohan , Lee, Justin Z. , Munoz, Freddy Del‐Carpio , Siontis, Konstantinos C. , Deshmukh, Abhishek , Del-Carpio Munoz, Freddy , Siontis, Konstantinos C , Link, Mark S. , Deshmukh, Abhishek J , DeSimone, Christopher V , Ahmed, Mahmoud , Mohamed, Kareem A., Elfert, Khaled , Rao, Mohan, Asad, Zain Ul Abideen , DeSimone, Christopher V.

Journal of Cardiovascular Electrophysiology | November 5, 2025 | Volume: 37 | Issue: 1 | Pages: 26-35

10.1111/jce.70166 Get It

ABSTRACT Background Early catheter ablation for atrial fibrillation (AF) improves outcomes, but the optimal timing, especially in heart failure (HF) subtypes, remains unclear. Objective To evaluate the impact of ablation timing on outcomes in patients with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF). Methods We used the TriNetX database (2010–2024) to identify HF patients with AF who underwent ablation. Patients were classified as early ablation (≤ 1 year of first AF diagnosis) or delayed ablation (1–3 years), with propensity score matching (PSM) applied to balance the baseline characteristics. The primary outcome was AF recurrence, defined by repeat ablation, direct current cardioversion (DCCV), or antiarrhythmic drug (AAD) use after a 3‐month blanking period. Secondary outcomes included stroke, hospitalization, and mortality over 5 years. Results After PSM, delayed ablation was associated with higher AF recurrence in both HFrEF (HR = 1.28, p < 0.001) and HFpEF (HR = 1.21, p = 0.02), as seen in multivariate analysis. In HFrEF, delayed ablation was associated with higher incidence of re‐do ablation, AAD use, and DCCV, while in HFpEF, higher recurrence with delayed ablation was associated with increased AAD use. Both cohorts had similar stroke and mortality rates between early and delayed ablation. Conclusions Delayed ablation in HFrEF and HFpEF was linked to higher AF recurrence, driven by increased redo ablations, DCCV, AAD use in HFrEF, and higher AAD use in HFpEF. Stroke, HF hospitalization and mortality rates were similar, suggesting earlier ablation may enhance rhythm control over other outcomes.
Trends and Disparities in Ventricular Tachycardia‐Related Mortality According to Cardiomyopathy Type in the United States
Sheffeh, Mohammad Ali , Estrada-Magana, Andres , Siontis, Konstantinos C. , Liang, Jackson J. , Magana, Andres Estrada, Siontis, Konstantinos C , Liang, Jackson , Lavallaz, Jeanne du Fay de

Journal of Cardiovascular Electrophysiology | September 29, 2025 | Volume: 36 | Issue: 11 | Pages: 3054-3057

10.1111/jce.70116 Get It

ABSTRACT Background Recent data show increased ventricular tachycardia (VT) related mortality. We aimed to investigate the trends and disparities of VT‐related mortality according to cardiomyopathy subtypes. Methods Mortality and demographic data were obtained from the CDC Wide‐ranging Online Data for Epidemiologic Research database between 1999 and 2020. VT‐related mortality was defined as the underlying cause of death and ischemic cardiomyopathy (ICM) or nonischemic cardiomyopathy (NICM) as the contributing cause of death. The direct method of standardization was utilized to estimate age‐adjusted mortality rates (AAMRs). Temporal trends were evaluated using log‐linear regression models. Results A total of 15 888 deaths were related to both VT and ICM, and 16 777 were due to both VT and NICM. There was a significant increase in VT and ICM‐related mortality between 2006 and 2020 with an APC of +1.38% ( p < 0.05). Similarly, VT and NICM‐related mortality increased between 2008 and 2020 with an APC of +0.60% ( p < 0.05). ICM had a higher AAMR in males [6.23 (6.12–6.34)], Whites [3.49 (3.43–3.54)], Hispanics [2.11 (1.95–2.26)], and the Midwest region [3.73 (3.61–3.85)] compared to NICM. In contrast, NICM had a higher AAMR in females [1.57 (1.52–1.61)], Black or African Americans [5.02 (4.84–5.20)], and the South region [3.10 (3.03–3.18)]. p for all trend < 0.05. Conclusions Real‐world data show significant differences in VT‐related mortality according to cardiomyopathy subtypes with prominent sex, race, and regional disparities. Clinical and public health strategies are needed to address inequities and improve outcomes.
Catheter Ablation for Ventricular Tachycardia in Ischemic Cardiomyopathy: A Meta‐Analysis With Reconstructed Time‐to‐Event and Trial Sequential Analysis
Elbenawi, Hossam , Ayman, Youmna , Hashim, Ahmed , Wagdy, Mohamed, Thakurathi, Priyesh , Al‐Shammari, Ali Saad , Mohamed, Kareem A., Kalaiger, Abdul M., Ibrahim, Ahmed M. , Eisa, Mahmoud , Ibrahim, Ramzi , Zaaya, Morad, Almaadawy, Omar , Quelal, Karol , Lee, Justin Z. , Siontis, Konstantinos C. , Munoz, Freddy Del‐Carpio , Deshmukh, Abhishek , Agarwal, Siddharth , Al-Shammari, Ali Saad , Ibrahim, Ramzi , Tan, Min Choon , Quelal, Karol , Asad, Zain Ul Abideen , Siontis, Konstantinos C , Del-Carpio Munoz, Freddy , DeSimone, Christopher V , Deshmukh, Abhishek J , Agarwal, Siddharth , Kalaiger, Abdul Mukhtadir , Agarwal, Siddharth, Wagdy, Mohamed , Hamed, Belal Mohamed , Mohamed, Kareem A., Ibrahim, Ramzi , Asad, Zain Ul Abideen , Arenal, Ángel , DeSimone, Christopher V.

Journal of Cardiovascular Electrophysiology | September 17, 2025 | Volume: 36 | Issue: 11 | Pages: 2934-2949

10.1111/jce.70075 Get It

ABSTRACT Background Ventricular tachycardia (VT) is a major contributor to sudden cardiac death among patients with ischemic heart disease (IHD). While catheter ablation reduces the arrhythmic burden, the impact on long‐term outcomes remains uncertain. We assess the efficacy of catheter ablation in patients with IHD. Methods We performed a meta‐analysis by systematically searching electronic databases from inception to April 2025. Pairwise, reconstructed time‐to‐event data meta‐analyses and Trial Sequential analyses were conducted. Results A total of seven studies (1192 participants) were included. Among patients with IHD with ICD, VT ablation was associated with a significant reduction in ICD shocks (RR = 0.50, 95% CI = [0.34–0.74]), a trend toward reduced VT storm (RR = 0.64, 95% CI = [0.40–1.04], p = 0.07), and lower rates of cardiovascular hospitalization (RR = 0.73, 95% CI = [0.53–1.01], p = 0.06) compared to ICD alone. However, no significant differences were observed when compared to patients receiving ICD plus antiarrhythmic drugs (AADs). VT ablation showed no significant impact on mortality or VT/VF recurrence compared to either ICD alone or ICD with AADs. Reconstructed Kaplan–Meier analysis for all‐cause mortality showed no significant difference between VT ablation and AAD + ICD. Trial Sequential Analysis provided conclusive evidence for VT/VF recurrence, while further data is required for other outcomes. Conclusion Among patients with IHD with ICD, VT ablation reduces ICD shocks, VT storm, and cardiovascular hospitalizations compared to ICD‐only therapy, but offers no significant advantage over ICD combined with AADs. VT ablation does not impact overall mortality or the recurrence of VT/VF. Trial sequential analysis confirmed conclusive evidence for VT/VF recurrence, while additional data is needed for other outcomes.
Effectiveness and Safety of Intramyocardial Needle Ablation for Refractory Ventricular Tachycardia and Premature Ventricular Complexes: A Systematic Review and Meta‐Analysis
Qureshi, Muhammad Ahmad , Rawlley, Bharat , Jain, Vardhmaan, Verma, Atul, Siontis, Konstantinos C. , Deshmukh, Abhishek , Khan, Arfaat , Gupta, Kartik , Rawlley, Bharat , Siontis, Konstantinos C , Deshmukh, Abhishek J , Jain, Vardhmaan, Verma, Atul, Raad, Mohamad

Journal of Cardiovascular Electrophysiology | July 14, 2025 | Volume: 36 | Issue: 9 | Pages: 2279-2286

10.1111/jce.70000 Get It

ABSTRACTIntroductionIntramyocardial needle ablation is a novel technique for treating refractory ventricular tachycardia (VT) and premature ventricular complexes (PVC). However, studies defining the effectiveness and safety of this procedure are limited. This meta‐analysis aims to evaluate the safety and effectiveness of needle ablation for VT and PVC refractory to standard ablation.MethodsEmbase, Ovid (includes Medline), and ClinicalTrials.gov were searched from inception to December 31, 2024. Human studies on needle ablation for recurrent VT and PVC were included. Primary outcome was immediate effectiveness (no immediate post‐procedural inducible VT or PVC). Secondary outcomes were long‐term effectiveness (no clinical VT or PVC at 6 months) and safety (composite measure of peri‐ and post‐procedural complications).ResultsA total of five studies including 180 patients (140 VT; 40 PVC) were analyzed. Mean ages ranged from 54 to 66 years. Among 129 patients with VT, immediate effectiveness was 75% (95% CI, 54–92; I2 80%), and cumulative freedom from clinical VT dropped to 43% at 6 months (95% CI, 35–52; I2 0%). Among 40 patients with PVC, immediate effectiveness was 82% (95% CI, 67–94; I2 0%), and long‐term effectiveness was 76% (95% CI, 61–90; I2 0%). Safety outcomes were reported in 19% of patients (95% CI, 13–27; I2 0%) and 10% of patients (95% CI 1, 23; I2 0%) in the VT and PVC arm, respectively. Death related to ablation was report in 7 patients (5.0%) only in the VT studies.ConclusionIntramyocardial needle ablation is an emerging alternative approach for refractory VT and PVC ablation, showing cautious but promising results and safety profiles. Prospective studies and an international registry could provide valuable insights needed for optimal patient selection and protocol refinement.
Recent-onset atrial fibrillation: challenges and opportunities
Svennberg, Emma , Andrade, Jason G. , Anselmino, Matteo , Biton, Yitschak , Brandes, Axel , Buckley, Claire , Espuny, Josep Lluis Clua , Doehner, Wolfram , Domínguez, Helena , Fauchier, Laurent , Glotzer, Taya V. , Hendriks, Jeroen , Hills, Mellanie True , Hindricks, Gerhard , Joung, Boyoung , Levin, Lars‐Åke , Liu, Shaowen , Lobban, Trudie , Macfarlane, Peter W. , Mairesse, Georges H. , Marcus, Gregory M. , Orchard, J. , Reiffel, James A. , Siontis, Konstantinos C. , Stavrakis, Stavros , Svendsen, Jesper Hastrup , Teh, A. , Tieleman, Robert G , Camm, A. John , Freedman, Ben , Andrade, Jason G , Anselmino, Matteo , Biton, Yitschak , Boriani, Giuseppe , Brandes, Axel , Buckley, Claire , Cameron, Alan C , Lluis Clua Espuny, Josep , Crijns, Harry J G M , Diederichsen, Søren Z , Doehner, Wolfram , Dominguez, Helena , Duncker, David , Fauchier, Laurent , Glotzer, Taya , Guo, Yutao , Haeusler, Karl G , Haim, Moti , Healey, Jeffrey S , Hendriks, Jeroen M , True Hills, Mellanie , Hindricks, Gerhard , Hobbs, F D Richard , Johnson, Linda S B , Joung, Boyoung , Kamel, Hooman , Kirchhof, Paulus , Lane, Deirdre A , Levin, Lars-Åke , Lip, Gregory Y H , Liu, Shaowen , Lobban, Trudie , Macfarlane, Peter W , Mairesse, Georges , Marcus, Gregory M , Noseworthy, Peter A , Ntaios, George , Orchard, Jessica J , Passman, Rod , Reidpath, Daniel D , Reiffel, James A , Ribeiro, Antonio Luiz , Rivard, Lena , Sanders, Prashanthan , Sandhu, Roopinder K , Schnabel, Renate B , Siontis, Konstantinos C , Sposato, Luciano A , Stavrakis, Stavros , Steinhubl, Steven , Svendsen, Jesper Hastrup , Teh, Andrew W , Themistoclakis, Sakis , Tieleman, Robert G , Camm, Alan John , Freedman, Ben , Boriani, Giuseppe , Cameron, Alan C. , Crijns, Harry J.G.M. , Diederichsen, Søren Zöga , Duncker, David , Haim, Moti , Healey, Jeff S. , Hobbs, Richard , Johnson, Linda S.B. , Kamel, Hooman , Kirchhof, Paulus , Lane, Deirdre A. , Noseworthy, Peter A. , Passman, Rod , Rivard, Léna , Sanders, Prashanthan , Schnabel, Renate B. , Sposato, Luciano A. , Tieleman, RG

European Heart Journal | June 23, 2025 | Volume: 47 | Issue: 2 | Pages: 170-187

10.1093/eurheartj/ehaf478 Get It

Abstract Atrial fibrillation (AF) is increasingly diagnosed early, close to its first occurrence due to: (i) increased public awareness with self-screening; (ii) health care initiatives including population screening and opportunistic case finding; and (iii) increased use and surveillance of implantable cardiac devices. At its onset, AF is often low burden, and cardiovascular co-morbidities may be absent or at an early stage. Thus, the management of recent-onset AF has become an issue of growing importance. Professional guidelines have traditionally focused on anticoagulant thromboprophylaxis, generally recommending a cautious approach to rhythm control, and priority has been given to rate control to alleviate symptoms. In recent guidelines, the importance of managing lifestyle and co-morbidities has increased. The AF-SCREEN collaboration proposes that a vigorous approach to active management of recent-onset AF may be warranted. This includes addressing co-morbidities and promoting healthy lifestyles to prevent the emergence or progression of AF and associated cardiovascular disease, as well as the initiation of active rhythm control ± anticoagulation to prevent AF-related morbidity and mortality, including stroke and heart failure (HF). Intuitively, intervention early after AF onset would be beneficial since lifestyle and co-morbidity management, plus rhythm control and anticoagulation, are important contributors to improved outcomes in patients with established AF, but robust evidence is lacking for recent-onset AF. There is a delicate balance between achieving favourable outcomes such as preventing strokes, HF and AF progression vs the complications and potential adverse effects of interventions. Given the serious long-term consequences, innovative approaches are necessary to determine the value and risks of initiating active therapy very early in the course of AF. More data are needed to guide the best management of recent-onset AF, bearing AF burden in mind. Long-term studies using large national databases linked to electronic medical records and rhythm monitoring devices offer excellent opportunities. Shorter-term studies focusing on reducing AF burden to slow AF progression and studies focusing on outcomes such as HF could be used in both randomized clinical trials and observational cohort studies.