Feasibility of Patient-Managed ECG Recordings to Detect the Time of Atrial Fibrillation Recurrence after Electrical Cardioversion: Results from the PRE-ELECTRIC Study.

BACKGROUND: Electrical cardioversion (ECV) is a common procedure to terminate persistent atrial fibrillation (AF). The recurrence rate is high, and the patients often fail to recognize AF recurrence. OBJECTIVES: The aim of the study was to evaluate the feasibility of patient-managed electrocardiography (ECG) to detect the time to AF recurrence after ECV. METHODS: PRE-ELECTRIC (predictors for recurrence of atrial fibrillation after electrical cardioversion) is a prospective, observational study. Patients ≥18 years of age scheduled for ECV of persistent AF at Bærum Hospital were eligible for inclusion in the study. Time to recurrence of AF was detected by thumb ECG, recorded twice daily and whenever experiencing symptoms. The observation period was 28 days. We defined adherence as the observed number of days with ECG recordings divided by the expected number of days with ECG recordings. Study personnel contacted the participants by phone to assess their awareness of AF recurrence after a recurrence was detected in the thumb ECG. RESULTS: The study enrolled 200 patients scheduled for ECV of persistent AF at Bærum Hospital between 2018 and 2022. The mean age was 66.2 ± 9.3 years, and 21.0% (42/200) were women. The most frequent comorbidities were hypertension (n = 94, 47.0%) and heart failure (n = 51, 25.5%). A total of 164 participants underwent ECV of AF. The procedure was initially successful in 90.9%, of which 50.3% had a recurrence of AF within 4 weeks. The median time to recurrence was 5 days. Among the cardioverted participants, 123 (75.0%) had no missing days of thumb ECG recording during the observation period, and 97.0% had ≤3 missing days. More than a third (37.3%) of the participants with AF recurrence were unaware of the recurrence at the time of contact. Women were older and more symptomatic than men but had similar outcomes after ECV. CONCLUSIONS: Recurrence of AF after ECV was common. Using patient-managed thumb ECG was a feasible method to detect AF recurrence following ECV. Further studies are needed to investigate whether patient-managed ECG after ECV can optimize AF treatment.

High-sensitivity troponin I in persistent atrial fibrillation - relation to NT-proBNP and markers of inflammation and haemostasis.

PURPOSE: As cardiac troponins emerge as prognostic markers in atrial fibrillation (AF), it is important to identify mechanisms initiating and perpetuating cardiac troponin release, including its relations to other circulating biomarkers, in AF populations. We studied associations between high-sensitivity troponin I (hs-TnI) and markers representing myocardial wall tension, inflammation and haemostasis in persistent AF. METHODS: In a double blind, placebo-controlled study, 171 patients referred for electrical cardioversion for persistent AF were randomised to receive candesartan or placebo for 3-6 weeks before and 6 months after cardioversion. Associations between baseline levels of hs-TnI and other biomarkers were investigated by bivariate non-parametric correlations (Spearman's correlation coefficient denoted rs). RESULTS: Baseline levels of hs-TnI correlated significantly, although weakly, with interleukin-6 (rs = 0.260, p = .003), N-terminal pro-B-type natriuretic peptide (rs = 0.251, p = .004), tissue-plasminogen activator antigen (rs = 0.233, p = .008), D-dimer (rs = 0.220, p = .013), E-selectin (rs = 0.207, p = .019), high-sensitivity C-reactive protein (rs = 0.202, p = .022) and vascular cell adhesion molecule-1 (rs = 0.189, p = .032). CONCLUSIONS: Hs-TnI correlated weakly with biomarkers representing myocardial wall tension, inflammation and haemostasis in persistent AF. The lack of any strong correlation between hs-TnI and the investigated biomarkers is in concert with the idea that hs-TnI release is an independent process parallel to other pathophysiological mechanisms associated with AF.

High-Sensitivity Troponin I and Rhythm Outcome after Electrical Cardioversion for Persistent Atrial Fibrillation.

OBJECTIVES: We hypothesised that high-sensitivity troponin I (hs-TnI) might predict long-term rhythm outcome after cardioversion for persistent atrial fibrillation (AF), and that maintenance of sinus rhythm and/or treatment with the angiotensin II type 1 receptor blocker candesartan would reduce hs-TnI levels. METHODS: In a double-blind, placebo-controlled study, 171 patients referred for electrical cardioversion for AF were randomised to receive candesartan or placebo for 3-6 weeks before cardioversion and for 6 months after electrical cardioversion. Blood samples for analysis of hs-TnI (Abbott Diagnostics) were available in 129 patients at baseline and in 60 successfully cardioverted patients at study end. RESULTS: Hs-TnI was detectable in all subjects, with a median value of 5.3 ng/l (25th percentile 3.7, 75th percentile 7.2). hs-TnI at baseline was not predictive of rhythm outcome 6 months after electrical cardioversion for persistent AF. Treatment with candesartan did not influence the levels of hs-TnI. hs-TnI was unchanged from baseline to study end in patients who maintained sinus rhythm [4.9 (3.7, 7.0) and 5.0 (4.0, 6.4) ng/l, respectively; p = 0.699). CONCLUSIONS: hs-TnI did not predict AF recurrence after cardioversion. hs-TnI levels were unchanged in patients maintaining sinus rhythm for 6 months after electrical cardioversion. hs-TnI levels were not influenced by treatment with candesartan.

Troponin I levels in permanent atrial fibrillation-impact of rate control and exercise testing.

BACKGROUND: High-sensitivity troponin I (hs-TnI) and troponin T (hs-TnT) are moderately correlated and independently related to outcome in atrial fibrillation (AF). Rate controlling therapy has been shown to reduce hs-TnT, however the potential impact on hs-TnI levels, and whether this differs from the effects on hs-TnT, has not been investigated previously. METHODS: Sixty patients with stable, permanent AF without heart failure or known ischemic heart disease were included in a randomised crossover study (mean age 71 ± 9 years, 18 women). Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered once daily for three weeks, in a randomised sequence. At baseline and on the last day of each treatment period, hs-TnI was measured at rest and after a maximal exercise test and compared to hs-TnT. RESULTS: Hs-TnI and hs-TnT correlated moderately at baseline (rs = 0.582, p < 0.001). All drugs reduced both the resting and the peak exercise levels of hs-TnI compared with baseline (p < 0.001 for all). The decline in resting hs-TnI and hs-TnT values relative to baseline levels was similar for all drugs except for verapamil, which reduced hs-TnI more than hs-TnT (p = 0.017). Levels of hs-TnI increased significantly in response to exercise testing at baseline and at all treatment regimens (p < 0.001 for all). The relative exercise-induced increase in hs-TnI was significantly larger compared to hs-TnT at baseline (p < 0.001), on diltiazem (p < 0.001) and on verapamil (p = 0.001). CONCLUSIONS: In our population of stable, permanent AF patients, all four rate control drug regimens reduced hs-TnI significantly, both at rest and during exercise. The decline in hs-TnI and hs-TnT levels associated with beta-blocker and calcium channel blocker treatment was similar, except for a larger relative decrease in hs-TnI levels following verapamil treatment. TRIAL REGISTRATION: www.clinicaltrials.gov ( NCT00313157 ).

Impact of atrial fibrillation on NT-proBNP levels in a 75-year-old population.

OBJECTIVE: The objective of this study was to investigate the impact of atrial fibrillation (AF) on serum levels of N-terminal fragment of pro-brain natriuretic peptide (NT-proBNP) in a 75-year-old population. METHODS: All 75-year-old citizens in Asker and Baerum counties in Norway were invited to participate in a prevalence study of AF. Blood samples for measurement of NT-proBNP were collected at rest from 61 subjects with AF and a gender-matched control group of 126 subjects in sinus rhythm. NT-proBNP was measured in serum using the Elecsys proBNP sandwich immunoassay (Roche Diagnostics, Basel, Switzerland). RESULTS: Subjects with permanent AF had higher levels of NT-proBNP (median 1119 pg/mL (interquartile range 701, 1643)) than subjects with paroxysmal AF (257 pg/mL (169, 382)) and controls (95 pg/mL (60, 171)), p<0.001 for both.The presence of AF was still significantly associated with higher log NT-proBNP (B=0.61, p<0.001) after adjusting for the presence of heart failure, coronary heart disease and hypertension. CONCLUSION: In this stable, out-of-hospital population of 75-year-old subjects, AF was independently associated with increased levels of NT-proBNP. Permanent AF was associated with higher NT-proBNP levels than paroxysmal AF.

Exercise in individuals with atrial fibrillation.

BACKGROUND: Despite the high prevalence of atrial fibrillation (AF), there is a lack of recommendations for physical activity and exercise in individuals with AF, including athletes with AF. METHODS: With the aim to review studies that have investigated effects and safety of exercise in individuals with AF, we conducted a literature search in Pubmed using the key words atrial fibrillation AND exercise OR physical activity OR exercise/adverse effects OR adverse outcome. RESULTS: Observational data from one registry suggest that regular exercise is associated with reduced mortality in AF patients. Three randomized controlled trials (RCTs) have demonstrated that 12-week exercise interventions might reduce the burden of AF and improve exercise capacity by 10-16% in patients with paroxysmal or persistent AF. Three small RCTs suggest that exercise might improve exercise capacity with 15-41% in patients with permanent AF. Exercise might improve quality of life in patients with AF. Data on safety of exercise are sparse. No studies have evaluated the effect of exercise in athletes with AF. CONCLUSIONS: Despite weak evidence, we suggest that individuals with AF should exercise regularly after evaluation of underlying conditions. Recommendations should be individualized. There is a lack of data to support exercise recommendations in athletes with AF.