The Year in Cardiovascular Medicine: Arrhythmias 2020 reviews the most relevant studies in the field of arrhythmias and pacing. The past year has shown a significant progress: landmark clinical trials in atrial fibrillation (AF) and implantable defibrillator (ICD) therapy, new guidelines, integrated care, life style and arrhythmias, His bundle pacing, risk prediction in sudden cardiac death, and advances in cardiogenetics.

The guidelines on supraventricular tachycardia (SVT) and AF brought many new insights and recommendations. (1, 2) The former dealt with SVT ablation as an early strategy and invasive risk assessment in ventricular preexcitation. Its focus also was on what-to-avoid in management of SVT. (2) The new guidelines on AF promote the slogan ‘CC to ABC’, indicating that electrical Confirmation of AF is mandatory together with in-depth Characterisation of AF (Figure 1). (1) For management the AF guidelines advise to follow the Atrial fibrillation Better Care (ABC) pathway, which represents care to (i) avoid stroke, (ii) better symptom control, and (iii) take care of co-morbidities and cardiovascular risk factors. Despite the lack of data to show clinical effectiveness, AF screening is advocated saying that once AF is detected outcome worsens. It is also recommended to measure the quality of care over time and when needed improve care in an iterating cycle of improvement. The guidelines also highlight the importance of longitudinal rather than one-time cross-sectional assessment of stroke and bleeding risks since patients may outgrow their low risk status quite rapidly over time. Catheter ablation is advocated to ameliorate AF symptoms and to manage AF-associated heart failure and may be applied after one antiarrhythmic drug failure including failure on beta-blockade.

Interesting randomized trials on integrated AF management included the ALL-IN trial, a cluster randomized trial in elderly AF patients in primary care, which showed that integrated care delivered by practice nurses supervised by general practitioners reduced all-cause mortality by 45% compared to usual-care. (3) This is impressive and highlights the power of ‘simple’ interventions if deployed systematically. The integrated care pathway included quarterly AF check-ups by the practice nurse, case management of antithrombotic treatment, and easy-access consultation of a cardiologist. This represents patient-centered shared responsibilities between primary care, anticoagulation clinics, cardiologists, and patients. Similarly, RACE 4 reported that nurse-led, information and communication technology (ICT)-supported, and physician-supervised integrated care reduces morbidity and mortality in experienced centres but not in less-experienced centres and emphasized the importance of training in an integrated environment. (4) Key elements of integrated care in these trials were the multidisciplinary team approach, education, and empowerment of patients and where possible application of decision support technology.

Recent mHealth solutions include TeleCheck-AF (5, 6) and a mobile AF application incorporating the ABC pathway (Figure 1). (7) The mAFA II trial reported a significant reduction in all-cause death and adverse cardiovascular events compared to routine management in high-risk AF. (7) Notably, single elements of integrated care such as application of a clinical decision support system, (8) an educational (9) or a motivational (10) intervention to improve anticoagulation or introduction of shared decision-making (11) improve the level of care but not prognosis.

In integrated care, patient-driven life-style changes targeting obesity, alcohol, and blood pressure control is important before performing rhythm control with catheter ablation. In a large cohort of 402 406 individuals from the UK Biobank, regular physical activity was related with a lower incidence of AF (especially in women) and ventricular arrhythmias but not of bradyarrhythmias. (12) Also, a randomized trial provided proof-of-concept data to support alcohol cessation as secondary prophylaxis against AF in regular drinkers. (13) Per nature of the trial, it focused on one element of life style whilst a more comprehensive multi-level modification of AF risk factors may be needed to abrogate risks of AF in daily life. (14)

The EAST-AFNET 4 trial compared a rhythm with a rate control strategy in patients with early AF lasting <1 year. It showed that rhythm control therapy, i.e. antiarrhythmic drugs and ablation, in early AF reduced cardiovascular outcomes without increasing time spent in-hospital, and without safety concerns. (15) The results are at odds with older trials, which may relate to earlier intervention, safer use of antiarrhythmic drugs, and safe application of catheter ablation. In accordance with the AF Guidelines, (1, 16–18) rhythm control was applied on top of cardiovascular prevention. Like previous trials, (19–21) EAST-AFNET4 was a strategy evaluation and not a simple comparison of two treatment modalities meant to either maintain sinus rhythm or keeping adequate rate control like the CABANA trial. (22) EAST-AFNET4 included recently detected AF, which seems crucial since most events occur in the first year after AF detection. (23, 24) Early intervention is supported by two recent trials showing that cryoballoon ablation as initial therapy is superior to drug treatment. (25, 26) Therefore, initial AF care should be supervised by cardiologists rather than non-cardiologists since 1-year mortality and morbidity are lower if newly diagnosed AF is managed under cardiology care compared to non-cardiology care. (27, 28)

Early rhythm control in recent-onset AF in the emergency room was tested in another randomized study comparing procainamide and rescue electrical cardioversion if needed with immediate electrical cardioversion. (29) Both strategies were clinically highly effective, but the authors suggested that immediate cardioversion be preferred since less burdensome for patients and the hospital.

Catheter ablation may be particularly useful in heart failure with AF, (21, 30) to improve quality of life (31, 32) as well as to save costs. (33) One interesting observational study suggested that catheter ablation compared to drug treatment is associated with a lower incidence of vascular dementia. (34) To support or circumvent catheter ablation, recent reports advocated add-on renal denervation (35) or low level tragus stimulation. (36) In CASA-AF, (37, 38) single procedure thoracoscopic surgical left atrial posterior wall isolation was not superior to extensive point-by-point posterior wall isolation plus right and left isthmus ablation and came with higher costs and less gain in QALYs. However, the surgical lesion set was quite limited and surgical learning curve effects may have affected outcome.

The risk of stroke and other adverse outcomes after postoperative AF (POAF) was reported from the combined datasets of the randomized POISE trials on the effects of metoprolol vs. placebo, aspirin vs. placebo, and clonidine vs. placebo. (39) Patients with cardiovascular disease were undergoing non-cardiac surgery. POAF within 30 days after surgery was seen in 404 of 18 117 patients and was associated with 1-year stroke incidence of 5.6% compared to 1.5% in no-POAF patients. Also, risk of death (31.3% vs. 9.3%) and myocardial infarction (26.2 vs. 8.2) were increased (Figure 2). Risk reduction strategies still need to be investigated. This knowledge gap was unfortunately not filled by a recent randomized trial testing the sedative dexmedetomidine against placebo to reduce new-onset POAF as well as delirium in 798 patients undergoing cardiac surgery. (40) The incidence of new POAF (~32%) and delirium (~15%) did not differ between study groups.