GLORIA-AF registry

The GLORIA-AF registry was a prospective registry program that included 56 000 patients from 44 countries worldwide. The study was designed to obtain real-world data on the characteristics of patients who were newly diagnosed (<3 months from the baseline visit) with nonvalvular atrial fibrillation, on changes in treat- ment patterns, and on the outcomes of anticoagulation therapy in a broad patient population outside of randomized clinical trials. The phase 2 part of GLORIA-AF began after the approval of dabigatran, the first NOAC, and collected, among other things, data on the safety and effectiveness of dabigatran. Steffen Christow (DE) presented the main findings, showing that about two-thirds of the patients in Western Europe with newly diagnosed nonvalvular atrial fibrillation were asymp- tomatic or minimally symptomatic. In addition, the rate of previous stroke in these patients was more than twice as high as in symptomatic patients, despite observ- ing no differences in the CHA₂DS₂-VASc score, which may be explained by a longer, but hidden, and therefore, undiagnosed atrial fibrillation history.

Thoracoscopic ligation of the left atrial appendage

Kent Nilsson (US) presented the results from a study that included a consecu- tive cohort of 20 patients with absolute contraindications for anticoagulation who underwent thoracoscopic left atrial appendage ligation with the AtriClip, there-

by eliminating the need for periprocedural anticoagulation. The patients had a CHA₂DS₂-VASc score of 4.5±1, a HASBLED score of 3.3±0.78, and a mean age of 73.1±6.4 years. The investigators reported an acute procedural occlusion of 100%, with no leaks. Additional studies are needed to define the efficacy of this technique.

Systematic screening for atrial fibrillation: the ACE 1950 study

Trygve Berge (NO) presented the ACE 1950 study, which was designed to investi- gate the yield of screening for atrial fibrillation in 65-year-old individuals from the general population in Norway who had risk factors for stroke. All people who were invited to undergo atrial fibrillation screening had a CHA₂DS₂-VASc score ≥2 for men or ≥3 for women and no history of atrial fibrillation (n=1601). The screening was performed using a portable handheld ECG recorder to collect 2-week inter- mittent ECG recordings. The screening revealed undiagnosed atrial fibrillation in 0.9% of participants included in the trial. The total prevalence of atrial fibrillation was 7.6 per 1 000 and the mean CHA₂DS₂-VASc score was 2.8±0.8 in the screened population. Arterial hypertension and diabetes mellitus were the most prevalent risk factors.

Indications and outcomes in patients with wearable cardioverter-defibrillators

Tanja Odeneg (AT) presented the results from the Austrian wearable cardiovert- er-defibrillator registry. This study included 720 patients from 56 centers who received a wearable cardioverter-defibrillator between 2010 and 2017. The median duration for wearing the device was 48 days (range, 1-436). The most common pa- tients using the wearable cardioverter-defibrillator were patients after an acute myocardial infarction with a significantly reduced ejection fraction (≤35%) and patients with nonischemic cardiomyopathies (18% and 20% of patients, respec- tively). Of those patients treated with a wearable cardioverter-defibrillator, 25 (3.8%) were appropriately shocked due to ventricular tachycardia / ventricular fibrillation events, while 4 (0.4%) were inappropriately shocked.

Subcutaneous ICD cohort: long-term complications

Anne-Floor Quast (NL) presented the 6-year follow-up analysis of the Dutch co- hort who received a subcutaneous ICD, showing that the 30-day complication rate was 3% (95% CI, 0% to 6%), while the long-term complication rate was 12% (95% CI, 6% to 18%). The annual complication rate was 2%.

A matched comparison of subcutaneous and transvenous ICD therapy

In this propensity-score matching analysis of the SIMPLE and EFFORTLESS stud- ies, a large number of matched patients with subcutaneous ICDs were followed for 60 months and compared with a similar group of patients who had a trans- venous ICD. Tom Brouwer (NL) presented data showing that, in the subcutaneous ICD group, the complication-free rate was 91.1% vs 92.7% in the transvenous ICD group (P=0.38), the device implantation pouch was free of problems in 96.6% vs 98.0% (P=0.25), the electrodes were free of problems in 99.1% vs 97.5% (P=0.055), the infection-free rate was 97.8% vs 99.5% (P=0.04), and there were no inappro- priate shocks in 99.3% vs 99.2% of the patients. Together, these results show that both approaches for ICD devices have comparable results during a long-term fol- low-up.

Detecting atrial fibrillation using smartphone applications

Two different smartphone applications for atrial fibrillation detection were com- pared and their sensitivity and specificity were evaluated. The first application (BeatScanner) utilized the smartphone’s accelerometer and gyroscopic sensors, while the second (Preventicus) utilized the smartphone’s camera function. Karim Nabeela (UK) presented data showing that the sensitivity and specificity for the identification of atrial fibrillation was 89% (95% CI, 79% to 95%) and 67% (95% CI,

55% to 78%) with BeatScanner compared with 94% (95% CI, 86% to 98%) and 96% (95% CI, 88% to 99%) for Preventicus. Finally, the user preference was 37% for BeatScanner and 63% for Preventicus.

Second-generation cryoballoon ablation in patients with paroxysmal atrial fibrillation

Robert Hokanson (US) presented the results of the 24-month safety and efficacy follow-up of the STOP-AF postapproval study. This study was the largest prospec- tive, multicenter FDA study in North America to assess the long-term safety and effectiveness of the Arctic Front Advance Cryoballoon system in patients with drug-refractory recurrent symptomatic paroxysmal atrial fibrillation. Acute proce- dural pulmonary vein isolation was achieved in 342 of the 344 enrolled patients (99.4%). In 89% of the procedures, a 28-mm balloon was used exclusively; each pa- tient received 9.1±2.7 applications. The mean balloon temperatures for the 28-mm and 23-mm balloons were -47.5°C and -53.1°C, respectively. There were 20 patients (5.8%) with major procedure-related events and 11 patients (3.2%) with phrenic nerve injury that was unresolved before hospital discharge. No device- or proce- dure-related deaths were reported. Concerning the efficacy of the technique, the results showed that 82% of the patients were free from atrial fibrillation at 1 year and 75.3% at 2 years. Freedom from atrial fibrillation and symptomatic atrial flut- ter / atrial tachycardia was 79.5% at 1 year and 72.3% at 2 years.

The new diagnostic and therapeutic modalities for arrhythmias are evolving at a steady pace, although for pacing there is a relative stagnation if leadless pacing is excluded. In contrast, there is a continuing evolution of wearable and implantable devices related to rhythm monitoring because digital health – and especially tele- health – is increasingly becoming the domain with extremely promising prospects. Finally, for ICDs, subcutaneously implanted devices are becoming established as a reliable technique with a particularly promising future that will deal more effectively with one of the most lethal mistakes of nature, namely ventricular fibrillation.