Long-term Rate of Ventricular Arrhythmia in Autoimmune Disease.

AIMS: Although selected autoimmune diseases (AIDs) have been linked to an increased risk of ventricular arrhythmias (VAs), data on the long-term rate of VAs across the spectrum of AIDs are lacking. The aim of our study was to investigate the long-term rate of VAs (a composite of ventricular tachycardia, ventricular fibrillation, ventricular flutter, or cardiac arrest) in individuals with a history of 28 different AIDs. METHODS: Individuals diagnosed with an AID (2005-2018) were identified through Danish nationwide registries. Each patient with AID was matched with four individuals from the background population by age and sex. Multivariable Cox regression was used to compare the rate of VAs between the AIDs and background population, overall and according to individual AIDs. RESULTS: In total, 186,733 patients diagnosed with AIDs were matched with 746,932 individuals without AIDs (median age 55 years; 63% female; median follow-up 6.0 years). The 5-year cumulative incidence of VAs was 0.5% for patients with AIDs and 0.3% for matched individuals. Patients with any AIDs had a higher associated rate of VAs than matched individuals (HR 1.39 [95% CI, 1.29-1.49]). The highest HR was observed in patients with systemic sclerosis (3.86 [95% CI, 1.92-7.75]). The higher rate of VAs in patients with AIDs, compared with individuals from the background population, was more pronounced in patients without ischemic heart disease or heart failure/cardiomyopathy compared to those with these conditions (Pinteraction < 0.05). CONCLUSIONS: Despite a low cumulative incidence, patients with a history of AIDs had a higher relative rate of VAs than matched individuals.

In a large Danish nationwide study, we examined the risk of ventricular arrhythmias, which are serious and potentially life-threatening conditions, in patients with and without a history of autoimmune diseases. Patients with a history of any autoimmune disease had a higher risk of experiencing ventricular arrhythmias compared with age- and sex-matched individuals from the background population. This association was observed for most of the autoimmune diseases when examined individually. The higher rate of ventricular arrhythmias in patients with autoimmune diseases, compared with individuals from the background population, was relatively more pronounced in patients without a history of ischemic heart disease or heart failure/cardiomyopathy compared with individuals with a history of these conditions.

Implantable loop recorder detection of atrial fibrillation to prevent stroke (The LOOP Study): a randomised controlled trial.

BACKGROUND: It is unknown whether screening for atrial fibrillation and subsequent treatment with anticoagulants if atrial fibrillation is detected can prevent stroke. Continuous electrocardiographic monitoring using an implantable loop recorder (ILR) can facilitate detection of asymptomatic atrial fibrillation episodes. We aimed to investigate whether atrial fibrillation screening and use of anticoagulants can prevent stroke in individuals at high risk. METHODS: We did a randomised controlled trial in four centres in Denmark. We included individuals without atrial fibrillation, aged 70-90 years, with at least one additional stroke risk factor (ie, hypertension, diabetes, previous stroke, or heart failure). Participants were randomly assigned in a 1:3 ratio to ILR monitoring or usual care (control) via an online system in permuted blocks with block sizes of four or eight participants stratified according to centre. In the ILR group, anticoagulation was recommended if atrial fibrillation episodes lasted 6 min or longer. The primary outcome was time to first stroke or systemic arterial embolism. This study is registered with ClinicalTrials.gov, NCT02036450. FINDINGS: From Jan 31, 2014, to May 17, 2016, 6205 individuals were screened for inclusion, of whom 6004 were included and randomly assigned: 1501 (25·0%) to ILR monitoring and 4503 (75·0%) to usual care. Mean age was 74·7 years (SD 4·1), 2837 (47·3%) were women, and 5444 (90·7%) had hypertension. No participants were lost to follow-up. During a median follow-up of 64·5 months (IQR 59·3-69·8), atrial fibrillation was diagnosed in 1027 participants: 477 (31·8%) of 1501 in the ILR group versus 550 (12·2%) of 4503 in the control group (hazard ratio [HR] 3·17 [95% CI 2·81-3·59]; p<0·0001). Oral anticoagulation was initiated in 1036 participants: 445 (29·7%) in the ILR group versus 591 (13·1%) in the control group (HR 2·72 [95% CI 2·41-3·08]; p<0·0001), and the primary outcome occurred in 318 participants (315 stroke, three systemic arterial embolism): 67 (4·5%) in the ILR group versus 251 (5·6%) in the control group (HR 0·80 [95% CI 0·61-1·05]; p=0·11). Major bleeding occurred in 221 participants: 65 (4·3%) in the ILR group versus 156 (3·5%) in the control group (HR 1·26 [95% CI 0·95-1·69]; p=0·11). INTERPRETATION: In individuals with stroke risk factors, ILR screening resulted in a three-times increase in atrial fibrillation detection and anticoagulation initiation but no significant reduction in the risk of stroke or systemic arterial embolism. These findings might imply that not all atrial fibrillation is worth screening for, and not all screen-detected atrial fibrillation merits anticoagulation. FUNDING: Innovation Fund Denmark, The Research Foundation for the Capital Region of Denmark, The Danish Heart Foundation, Aalborg University Talent Management Program, Arvid Nilssons Fond, Skibsreder Per Henriksen, R og Hustrus Fond, The AFFECT-EU Consortium (EU Horizon 2020), Læge Sophus Carl Emil Friis og hustru Olga Doris Friis' Legat, and Medtronic.