Viveka Frykman

Anticoagulation control in Sweden: reports of time in therapeutic range, major bleeding, and thrombo-embolic complications from the national quality registry AuriculA

AIMS In anticoagulation treatment with warfarin, the risk of thrombo-embolic events must be weighed against the risk of bleeding. Time in therapeutic range (TTR) is an important tool to assess the quality of anticoagulation treatment, and has been shown to correlate with less bleeding and thrombo-embolic complications. AuriculA, the Swedish national quality registry for atrial fibrillation and anticoagulation, is used for follow-up and dosage control of warfarin. This is the first report of TTR in AuriculA and, in a subgroup of two centres, bleeding and thrombo-embolic complications during 2008. METHODS AND RESULTS Prothrombin complex (International normalized ratio) values from 18 391 patients in 67 different centres were analysed. The mean (SD) age was 70 (12) years. The main indications for warfarin treatment were: atrial fibrillation (64%), venous thromboembolism (19%), and heart valve dysfunction (13%). Time in therapeutic range for all patients was 76.2%. The mean weekly dose of warfarin decreased with age and TTR increased with age. In 4273 patients from two centres in AuriculA, the frequency of major bleedings and venous/arterial thrombo-embolism were 2.6 and 1.7% and for atrial fibrillation, 2.6 and 1.4%, per treatment year, respectively. A correlation between age and the risk of major bleeding (P< 0.001), but not thrombo-embolic complications (P= 0.147), was seen. CONCLUSION Compared with prospective randomized trials of warfarin treatment, TTR in the AuriculA population was higher. Complications were low, probably due to the organization of anticoagulation treatment in Sweden. Use of the AuriculA dosing programme could have contributed to the results by keeping dosing regimens consistent over all centres.

Mass Screening for Untreated Atrial Fibrillation The STROKESTOP Study

Background— The aims of the present study were to define the prevalence of untreated atrial fibrillation (AF) in a systematic screening program using intermittent ECG recordings among 75- to 76-year-old individuals and to study the feasibility of initiating protective oral anticoagulant (OAC) treatment. Methods and Results— Half of the 75- to 76-year-old population in 2 Swedish regions were invited to a screening program for AF. Participants without a previous diagnosis of AF underwent intermittent ECG recordings over 2 weeks. If AF was detected, participants were offered OAC. During the 28-month inclusion period, 13 331 inhabitants were invited. Of these, 7173 (53.8%) participated. Of the participants, 218 (3.0%; 95% confidence interval [CI], 2.7–3.5) were found to have previously unknown AF, and of these, AF was found in 37 (0.5% of the screened population) on their first ECG. The use of intermittent ECGs increased new AF detection 4-fold. A previous diagnosis of AF was known in 9.3% (n=666; 95% CI, 8.6–10.0). Total AF prevalence in the screened population was 12.3%. Of participants with known AF, 149 (2.1%; 95% CI, 1.8–2.4) had no OAC treatment. In total, 5.1% (95% CI, 4.6–5.7) of the screened population had untreated AF; screening resulted in initiation of OAC treatment in 3.7% (95% CI, 3.3–4.2) of the screened population. More than 90% of the participants with previously undiagnosed AF accepted initiation of OAC treatment. Conclusions— Mass screening for AF in a 75- to 76-year-old population identifies a significant proportion of participants with untreated AF. Initiation of stroke prophylactic treatment was highly successful in individuals with newly diagnosed AF. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01593553.

Use of an implantable loop recorder to increase the diagnostic yield in unexplained syncope: results from the PICTURE registry

Aims To collect information on the use of the Reveal implantable loop recorder (ILR) in the patient care pathway and to investigate its effectiveness in the diagnosis of unexplained recurrent syncope in everyday clinical practice. Methods and results Prospective, multicentre, observational study conducted in 2006–2009 in 10 European countries and Israel. Eligible patients had recurrent unexplained syncope or pre-syncope. Subjects received a Reveal Plus, DX or XT. Follow up was until the first recurrence of a syncopal event leading to a diagnosis or for ≥1 year. In the course of the study, patients were evaluated by an average of three different specialists for management of their syncope and underwent a median of 13 tests (range 9–20). Significant physical trauma had been experienced in association with a syncopal episode by 36% of patients. Average follow-up time after ILR implant was 10 ± 6 months. Follow-up visit data were available for 570 subjects. The percentages of patients with recurrence of syncope were 19, 26, and 36% after 3, 6, and 12 months, respectively. Of 218 events within the study, ILR-guided diagnosis was obtained in 170 cases (78%), of which 128 (75%) were cardiac. Conclusion A large number of diagnostic tests were undertaken in patients with unexplained syncope without providing conclusive data. In contrast, the ILR revealed or contributed to establishing the mechanism of syncope in the vast majority of patients. The findings support the recommendation in current guidelines that an ILR should be implanted early rather than late in the evaluation of unexplained syncope.

Short-term ECG for out of hospital detection of silent atrial fibrillation episodes

Objectives. We evaluated a short-term ECG, thumb ECG, for detection of asymptomatic atrial fibrillation (AF) episodes. The aim was to evaluate registration efficacy, sensitivity, specificity, quality and feasibility in patients with special emphasis on asymptomatic AF. Design. One hundred patients registered their cardiac rhythm with 12-lead ECG immediately followed by thumb ECG. The registrations were compared blindly. A second group of 12 patients, who had successfully undergone cardioversion, performed rhythm registration twice daily for 30 days. A third group of 606 individuals underwent an AF screening procedure. Results. Thumb ECG correctly diagnosed AF (sensitivity) in 96% and sinus rhythm (specificity) in 92% compared with 12-lead ECG. In the group of cardioverted patients, 466 registrations were validated: 95% had satisfactory quality for diagnosis: four patients experienced AF recurrence in which three were asymptomatic. In the third group 12 persons were diagnosed with AF, six of these had neither symptoms nor a history of AF. Conclusions. Short-term ECG is able to diagnose AF with a high sensitivity, specificity and simple application making detection of asymptomatic AF possible for screening purposes.

Population screening of 75- and 76-year-old men and women for silent atrial fibrillation (STROKESTOP)

Atrial fibrillation (AF) is important because it is common and is a major cause of stroke unless treated with oral anticoagulant. The prevalence of AF increases with age as does the risk of stroke. At 75 years the risk from age alone is so high that current guidelines recommend anticoagulation even in the absence of other risk factors. Atrial fibrillation is often asymptomatic and only discovered by chance or when a stroke already has occurred. We have launched a major screening study for silent AF in which 25,000 Swedes aged 75 and 76 years are randomized to either participate in a screening programme using ambulant intermittent electrocardiogram (ECG) recording to detect silent AF, or act as a control group. Patients in whom AF is detected are offered cardiological examination and anticoagulant treatment according to current guidelines. The cohort and the controls will be followed prospectively for 5 years after the inclusion of the first participant. An interim analysis will be made after 3 years. Our hypothesis is that screening for AF will reduce stroke incidence in the screened population, and that this screening will prove to be cost effective. Secondary endpoints are: any thromboembolic event, intracranial bleeding, other major bleeding, first ever diagnosis of dementia, death from any cause, and a composite of these endpoints.

Implantable Cardioverter-Defibrillator Therapy Before Death High Risk for Painful Shocks at End of Life

Background— Several trials have demonstrated improved survival with implantable cardioverter-defibrillator (ICD) therapy. The cause and nature of death in the ICD population have been insufficiently investigated. The objective of this study was to analyze ICDs from deceased patients to assess the incidence of ventricular tachyarrhythmias, the occurrence of shocks, and possible device malfunction. Methods and Results— We prospectively analyzed intracardiac electrograms in 125 explanted ICDs. The incidence of ventricular tachyarrhythmia, including ventricular fibrillation, and shock treatment was assessed. Ventricular tachyarrhythmia occurred in 35% of the patients in the last hour of their lives; 24% had an arrhythmic storm, and 31% received shock treatment during the last 24 hours. Arrhythmic death was the primary cause of death in 13% of the patients, and the most common cause of death was congestive heart failure (37%). More than half of the patients (52%) had a do-not-resuscitate order, and 65% of them still had the ICD shock therapies activated 24 hours before death. Possible malfunctions of the ICD were found in 3% of all patients. Conclusions— More than one third of the patients had a ventricular tachyarrhythmia within the last hour of life. Cardiac death was the primary cause and heart failure the specific cause of death in the majority of the cases. Devices remained active in more than half of the patients with a do-not-resuscitate order; almost one fourth of these patients received at least 1 shock in the last 24 hours of life.

Implantable Defibrillator Therapy Before Death: High Risk for Painful Shocks at End of Life

Background— Several trials have demonstrated improved survival with implantable cardioverter-defibrillator (ICD) therapy. The cause and nature of death in the ICD population have been insufficiently investigated. The objective of this study was to analyze ICDs from deceased patients to assess the incidence of ventricular tachyarrhythmias, the occurrence of shocks, and possible device malfunction. Methods and Results— We prospectively analyzed intracardiac electrograms in 125 explanted ICDs. The incidence of ventricular tachyarrhythmia, including ventricular fibrillation, and shock treatment was assessed. Ventricular tachyarrhythmia occurred in 35% of the patients in the last hour of their lives; 24% had an arrhythmic storm, and 31% received shock treatment during the last 24 hours. Arrhythmic death was the primary cause of death in 13% of the patients, and the most common cause of death was congestive heart failure (37%). More than half of the patients (52%) had a do-not-resuscitate order, and 65% of them still had the ICD shock therapies activated 24 hours before death. Possible malfunctions of the ICD were found in 3% of all patients. Conclusions— More than one third of the patients had a ventricular tachyarrhythmia within the last hour of life. Cardiac death was the primary cause and heart failure the specific cause of death in the majority of the cases. Devices remained active in more than half of the patients with a do-not-resuscitate order; almost one fourth of these patients received at least 1 shock in the last 24 hours of life.

Asymptomatic versus symptomatic persistent atrial fibrillation: clinical and noninvasive characteristics

Abstract. Frykman V, Frick M, Jensen‐Urstad M, Östergren J, Rosenqvist M (South Hospital and Karolinska Hospital, Karolinska Institute, Stockholm, Sweden). Asymptomatic versus symptomatic persistent atrial fibrillation: clinical and noninvasive characteristics. J Intern Med 2001; 250: 390–397.

Paroxysmal atrial fibrillation with silent episodes: Intermittent versus continuous monitoring

Objectives. Asymptomatic atrial fibrillation (AF) presents the same risk for cardioembolic events as symptomatic AF. Intermittent ECG recordings may be helpful in detecting asymptomatic paroxysmal arrhythmias. The objective of this study was to compare short intermittent heart rhythm recordings with or without symptoms with continuous ECG recordings. Design. Twenty-two patients with diagnosed symptomatic paroxysmal AF participated. Patients used a handheld transtelephonic ECG device for a 30-day period performing two registrations of 10 seconds per day. Additionally patients were asked to make registrations if arrhythmia symptoms occurred. Patients also performed a 24-hour ambulatory continuous ECG recording during a single twenty-four hours period of the 30 day period. AF was defined as an irregular ventricular rhythm without visible p-waves for at least 10 seconds.Results. 1425 intermittent ECG recordings were performed. AF episodes were diagnosed in 18 (82%) patients compared with 7 (32%) patients using continuous ECG, (p = 0.001). All patients with AF detected by continuous monitoring were also detected by intermittent recordings. Of the episodes, 16% were judged as symptomatic. Conclusion. Short-term ECG registrations over extended time periods seem to be a more sensitive tool, compared with short continuous ECG recordings, for detection of AF episodes.

Duration of warfarin sodium therapy prior to electrical cardioversion of atrial fibrillation

Abstract.  Ryman J, Frick M, Frykman V, Rosenqvist M (South Hospital and Karolinska Hospital, Stockholm, Sweden) Duration of warfarin sodium therapy prior to electrical cardioversion of atrial fibrillation. Journal of Intern Med 2003; 253: 76–80.