Tobias Toennis

Dr. Tobias Toennis

orcid

Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
2 July 2024 in European Heart Journal
Verified
Journal Article
Open access
PDF file
NBNina Becher
Nina Becher
AMAndreas Metzner
Andreas Metzner
TTTobias Toennis
Tobias Toennis
PKPaulus Kirchhof
Paulus Kirchhof
RSRenate B. Schnabel
Renate B. Schnabel
Atrial fibrillation (AF), the most common sustained cardiac arrhythmia, is not a dichotomous disease trait. Technological innovations enable long-term rhythm monitoring in many patients and can estimate AF burden. These technologies are already used to detect and monitor AF. This review describes the relation between AF burden and outcomes and potential effects of AF burden reduction. A lower AF burden is associated with a lower risk of stroke and heart failure in patients with AF: stroke risk without anticoagulation is lower in patients with device-detected AF and a low AF burden (stroke rate 1%/year) than in patients with persistent and permanent AF (stroke rate 3%/year). Paroxysmal AF shows intermediate stroke rates (2%/year). Atrial fibrillation burden–reducing interventions can reduce cardiovascular outcomes in patients with AF: early rhythm control reduces cardiovascular events including stroke and heart failure in patients with recently diagnosed AF and cardiovascular conditions. In patients with heart failure and AF, early rhythm control and AF ablation, interventions that reduce AF burden, reduce mortality and heart failure events. Recent technological innovations allow to estimate AF burden in clinical care, creating opportunities and challenges. While evidence remains limited, the existing data already suggest that AF burden reduction could be a therapeutic goal. In addition to anticoagulation and treatment of cardiovascular conditions, AF burden reduction emerges as a therapeutic goal. Future research will define the AF burden that constitutes a relevant risk of stroke and heart failure. Technologies quantifying AF burden need careful validation to advance the field.

30 March 2024 in EP Europace
Verified
Journal Article
Open access
PDF file
Dominik LinzDominik Linz
Dominik Linz
JAJason G Andrade
Jason G Andrade
Elena ArbeloElena Arbelo
Elena Arbelo
Giuseppe BorianiGiuseppe Boriani
Giuseppe Boriani
GBGuenter Breithardt
Guenter Breithardt
PKPaulus Kirchhof
Paulus Kirchhof
Aims: Recent trial data demonstrate beneficial effects of active rhythm management in patients with atrial fibrillation (AF) and support the concept that a low arrhythmia burden is associated with a low risk of AF-related complications. The aim of this document is to summarize the key outcomes of the 9th AFNET/EHRA Consensus Conference of the Atrial Fibrillation NETwork (AFNET) and the European Heart Rhythm Association (EHRA). Methods and results: Eighty-three international experts met in Münster for 2 days in September 2023. Key findings are as follows: (i) Active rhythm management should be part of the default initial treatment for all suitable patients with AF. (ii) Patients with device-detected AF have a low burden of AF and a low risk of stroke. Anticoagulation prevents some strokes and also increases major but non-lethal bleeding. (iii) More research is needed to improve stroke risk prediction in patients with AF, especially in those with a low AF burden. Biomolecules, genetics, and imaging can support this. (iv) The presence of AF should trigger systematic workup and comprehensive treatment of concomitant cardiovascular conditions. (v) Machine learning algorithms have been used to improve detection or likely development of AF. Cooperation between clinicians and data scientists is needed to leverage the potential of data science applications for patients with AF. Conclusions: Patients with AF and a low arrhythmia burden have a lower risk of stroke and other cardiovascular events than those with a high arrhythmia burden. Combining active rhythm control, anticoagulation, rate control, and therapy of concomitant cardiovascular conditions can improve the lives of patients with AF.

22 June 2023 in EP Europace
Verified
Journal Article
Open access
PDF file
TTTobias Toennis
Tobias Toennis
EBEmanuele Bertaglia
Emanuele Bertaglia
Axel BrandesAxel Brandes
Axel Brandes
Wolfgang DichtlWolfgang Dichtl
Wolfgang Dichtl
NFNina Fluschnik
Nina Fluschnik
PKPaulus Kirchhof
Paulus Kirchhof
Atrial high-rate episodes (AHRE) are atrial tachyarrhythmias detected by continuous rhythm monitoring by pacemakers, defibrillators, or implantable cardiac monitors. Atrial high-rate episodes occur in 10–30% of elderly patients without atrial fibrillation. However, it remains unclear whether the presence of these arrhythmias has therapeutic consequences. The presence of AHRE increases the risk of stroke compared with patients without AHRE. Oral anticoagulation would have the potential to reduce the risk of stroke in patients with AHRE but is also associated with a rate of major bleeding of ∼2%/year. The stroke rate in patients with AHRE appears to be lower than the stroke rate in patients with atrial fibrillation. Wearables like smart-watches will increase the absolute number of patients in whom atrial arrhythmias are detected. It remains unclear whether anticoagulation is effective and, equally important, safe in patients with AHRE. Two randomized clinical trials, NOAH-AFNET6 and ARTESiA, are expected to report soon. They will provide much-needed information on the efficacy and safety of oral anticoagulation in patients with AHRE.

12 November 2023 in European Heart Journal
Verified
Journal Article
Open access
PDF file
NBNina Becher
Nina Becher
TTTobias Toennis
Tobias Toennis
EBEmanuele Bertaglia
Emanuele Bertaglia
CBCarina Blomström-Lundqvist
Carina Blomström-Lundqvist
Axel BrandesAxel Brandes
Axel Brandes
PKPaulus Kirchhof
Paulus Kirchhof
Patients with long atrial high-rate episodes (AHREs) ≥24 h and stroke risk factors are often treated with anticoagulation for stroke prevention. Anticoagulation has never been compared with no anticoagulation in these patients. This secondary pre-specified analysis of the Non-vitamin K antagonist Oral anticoagulants in patients with Atrial High-rate episodes (NOAH-AFNET 6) trial examined interactions between AHRE duration at baseline and anticoagulation with edoxaban compared with placebo in patients with AHRE and stroke risk factors. The primary efficacy outcome was a composite of stroke, systemic embolism, or cardiovascular death. The safety outcome was a composite of major bleeding and death. Key secondary outcomes were components of these outcomes and electrocardiogram (ECG)-diagnosed atrial fibrillation. Median follow-up of 2389 patients with core lab-verified AHRE was 1.8 years. AHRE ≥24 h were present at baseline in 259/2389 patients (11%, 78 ± 7 years old, 28% women, CHA2DS2-VASc 4). Clinical characteristics were not different from patients with shorter AHRE. The primary outcome occurred in 9/132 patients with AHRE ≥24 h (4.3%/patient-year, 2 strokes) treated with anticoagulation and in 14/127 patients treated with placebo (6.9%/patient-year, 2 strokes). Atrial high-rate episode duration did not interact with the efficacy (P-interaction = .65) or safety (P-interaction = .98) of anticoagulation. Analyses including AHRE as a continuous parameter confirmed this. Patients with AHRE ≥24 h developed more ECG-diagnosed atrial fibrillation (17.0%/patient-year) than patients with shorter AHRE (8.2%/patient-year; P < .001). This hypothesis-generating analysis does not find an interaction between AHRE duration and anticoagulation therapy in patients with device-detected AHRE and stroke risk factors. Further research is needed to identify patients with long AHRE at high stroke risk. Anticoagulation with edoxaban in patients with long AHRE ≥24 h. AHRE, atrial high-rate episodes; CI, confidence interval; ECG, electrocardiogram; HR, hazard ratio.

2 September 2024 in European Heart Journal
Verified
Journal Article
Open access
PDF file
RSRenate B. Schnabel
Renate B. Schnabel
JBJuan Benezet-Mazuecos
Juan Benezet-Mazuecos
NBNina Becher
Nina Becher
WMWilliam F McIntyre
William F McIntyre
AFAlexander Fierenz
Alexander Fierenz
PKPaulus Kirchhof
Paulus Kirchhof
The optimal antithrombotic therapy in patients with device-detected atrial fibrillation (DDAF) is unknown. Concomitant vascular disease can modify the benefits and risks of anticoagulation. These pre-specified analyses of the NOAH-AFNET 6 (n=2534 patients) and ARTESiA (n=4012 patients) trials compared anticoagulation to no anticoagulation in patients with DDAF with or without vascular disease, defined as prior stroke/transient ischemic attack, coronary or peripheral artery disease. Efficacy outcomes were the primary outcomes of both trials, a composite of stroke, systemic arterial embolism (SE), myocardial infarction, pulmonary embolism or cardiovascular death, and stroke or SE. Safety outcomes were major bleeding or major bleeding and death. In patients with vascular disease (NOAH-AFNET 6 56%, ARTESiA 46.0%), stroke, myocardial infarction, systemic or pulmonary embolism, or cardiovascular death occurred at 3.9%/patient-year with and 5.0%/patient-year without anticoagulation (NOAH-AFNET 6), and 3.2%/patient-year with and 4.4%/patient-year without anticoagulation (ARTESiA). Without vascular disease, outcomes were equal with and without anticoagulation (NOAH-AFNET 6 2.7%/patient-year, ARTESiA 2.3%/patient-year in both randomised groups). Meta-analysis found consistent results across both trials (I2heterogeneity=6%) with a trend for interaction with randomised therapy (pinteraction=0.08). Stroke/SE behaved similarly. Anticoagulation increased major bleeding in vascular disease patients (edoxaban 2.1%/patient-year, no anticoagulation 1.3%/patient-year; apixaban 1.7%/patient-year; no anticoagulation 1.1%/patient-year; incidence rate ratio 1.55 [1.10-2.20]) and without vascular disease (edoxaban 2.2%/patient-year; no anticoagulation 0.6%/patient-year; apixaban 1.4%/patient-year; no anticoagulation 1.1%/patient-year, incidence rate ratio 1.93 [0.72-5.20]). Patients with DDAF and vascular disease are at higher risk of stroke and cardiovascular events and may derive a greater benefit from anticoagulation than patients with DDAF without vascular disease.

1 December 2025 in EP Europace
Verified
Journal Article
Open access
ESEmma Svennberg
Emma Svennberg
JMJose Luis Merino
Jose Luis Merino
JAJason G Andrade
Jason G Andrade
Matteo AnselminoMatteo Anselmino
Matteo Anselmino
Elena ArbeloElena Arbelo
Elena Arbelo
PKPaulus Kirchhof
Paulus Kirchhof
Atrial fibrillation (AF) is a growing unmet medical need. To reduce its impact on patients’ lives, improvements in stroke prevention therapy, treatment of concomitant conditions, and rhythm control therapy are actively developed: Innovations in anti-thrombotic agents, new anti-arrhythmic drugs (AADs), and novel interventional rhythm control therapies emerge alongside AF-reducing effects of general cardiometabolic therapies. Simple risk scores are slowly replaced by personalized AF risk estimation using quantifiable features. These developments were discussed by over 80 experts from academia and industry during the 10th Atrial Fibrillation NETwork /European Heart Rhythm Association consensus conference from 5 to 7 May 2025. The emerging consensus, described here, is multi-domain therapy combining stroke prevention, rhythm control, and therapy of concomitant cardiovascular conditions. This combines anti-coagulants, AADs, and AF ablation with old and new cardiometabolic drugs that can reduce AF risk, AF burden, and AF-related complications at scale. The paper furthermore describes quantitative traits that may enable a shift towards risk-driven therapy based on AF phenotypes. These can enable adjusted therapy strategies that are safe, accessible, and patient-centred. Applying modern data science and artificial intelligence methods to quantitative phenotypic and genetic features can further improve risk estimation and personalized therapy selection. At the same time, translational and clinical research into reversing the drivers of AF and into improved stroke prevention through new drugs and through combination therapies is needed. Together, these efforts offer pathways towards personalized, patient-centred, multi-modal, and accessible AF management that integrates rhythm control, stroke prevention, and therapy of concomitant conditions to bridge today’s practical needs with tomorrow’s therapeutic innovation.