Samuli Jaakkola

Mobile Phone Detection of Atrial Fibrillation With Mechanocardiography: The MODE-AF Study (Mobile Phone Detection of Atrial Fibrillation)

Because of the frequent asymptomatic presentation of atrial fibrillation (AF), stroke is too often its first manifestation.1 For effective stroke prevention, timely diagnosis of AF is crucial. Mobile devices are becoming ubiquitous, providing significant possibilities for screening applications. In mechanocardiography, mechanical cardiac activity is recorded with accelerometers and gyroscopes, standard components of modern smartphones.2 In our previous proof-of-concept study, smartphone mechanocardiography demonstrated 94% sensitivity and 100% specificity for detecting AF among 39 subjects.2 Here, we validate smartphone mechanocardiography detection of AF against visual interpretation of telemetry electrocardiographic recordings in hospitalized patients.

Incidence and predictors of excessive warfarin anticoagulation in patients with atrial fibrillation—The EWA study

Vitamin K antagonist warfarin is widely used in clinical practice and excessive anticoagulation is a well-known complication of this therapy. Little is known about permanent and temporary predictors for severe overanticoagulation. The aim of this study was to investigate the occurrence and predicting factors for episodes with very high (≥9) international normalized ratio (INR) values in warfarin treated patients with atrial fibrillation (AF). Excessive Warfarin Anticoagulation (EWA) study screened all patients (n = 13618) in the Turku University Hospital region with an INR ≥2 between years 2003–2015. Patients using warfarin anticoagulation for AF with very high (≥9) INR values (EWA Group) were identified (n = 412 patients) and their characteristics were compared to a control group (n = 405) of AF patients with stable INR during long-term follow-up. Over 20% (n = 92) of the EWA patients had more than one event of very high INR and in 105 (25.5%) patients EWA led to a bleeding event. Of the several temporary and permanent EWA risk factors observed, strongest were excessive alcohol consumption in 9.6% of patients (OR 24.4, 95% CI 9.9–50.4, p<0.0001) and reduced renal function (OR 15.2, 95% CI 5.67–40.7, p<0.0001). Recent antibiotic or antifungal medication, recent hospitalization or outpatient clinic visit and the first 6 months of warfarin use were the most significant temporary risk factors for EWA. Excessive warfarin anticoagulation can be predicted with several permanent and temporary clinical risk factors, many of which are modifiable.

Clinical manifestations and outcomes of severe warfarin overanticoagulation: from the EWA study

Abstract Introduction: Severe warfarin overanticoagulation is a risk factor for bleeding, but there is little information on its manifestations, prognosis and factors affecting the outcome. We describe the manifestations and clinical outcomes of severe warfarin overanticoagulation in a large group of patients with atrial fibrillation (AF). Material and methods: All international normalized ratio (INR) samples (n = 961,431) in the Turku University Hospital region between 2003 and 2015 were screened. A total of 412 AF patients with INR ≥9 were compared to 405 patients with stable warfarin anticoagulation for AF. Electronic patient records were manually reviewed to collect comprehensive data. Results: Of the 412 patients with INR ≥9, bleeding was the primary manifestation in 105 (25.5%). Non-bleeding symptoms were recorded in 165 (40.0%) patients and 142 (34.5%) had no symptoms. A total of 17 (16.2%) patients with a bleed and 67 (21.8%) without bleeding died within 30 days after the event. Intracranial haemorrhage strongly predicted death within 30 days. Other significant predictors were non-bleeding symptoms, active malignancies, recent bleed, history of myocardial infarction, older age, renal dysfunction and a recent treatment episode. Conclusions: Bleeds are not the major determinant of the poor prognosis in severe overanticoagulation, as coincidental INR ≥9 findings also associate with high mortality. KEY MESSAGES Only a quarter of AF patients with INR ≥9 suffered a bleeding event and the clinical manifestation of INR ≥9 had a significant impact on patient outcome. The 30-day mortality rate in patients with INR ≥9 was high ranging from 9.2 to 32.7%. Several significant predictors of 30-day mortality after INR ≥9 were identified.

Cardioversion for atrial fibrillation – how to prevent thromboembolic complications?

Abstract Cardioversion is an essential component of rhythm control strategy for atrial fibrillation. The thromboembolic risk of cardioversion is well established and the mechanisms behind the phenomenon have been comprehensively described. There are several clinical aspects that are important to take into consideration when assessing the safety of cardioversion. Before proceeding to cardioversion, the probability of early treatment failure and antiarrhythmic treatment options to prevent recurrences should be carefully evaluated to avoid the risks of repeated futile cardioversions. Effective periprocedural anticoagulation is the mainstay in thromboembolic complication prevention and the first week after rhythm conversion is the most vulnerable period in this respect. Early timing of cardioversion appears to be another important measure to decrease the risk of thromboembolic complications. Transoesophageal echocardiography is useful in clinical scenarios where early cardioversion is desirable due to debilitating clinical symptoms and a short duration of arrhythmia or the adequacy of preceding anticoagulation is uncertain. However, it does not lessen the need for effective anticoagulation after cardioversion. This review summarizes the recent scientific discoveries to improve the safety of cardioversion for atrial fibrillation. Key messages Cardioversion for atrial fibrillation entails a significant risk of thromboembolic complications, especially during the first week after the procedure. The intensity of periprocedural anticoagulation and the timing of cardioversion appear to be significant determinants of the risk of thromboembolism. Awareness of the clinical aspects influencing cardioversion safety should be raised.

Usefulness of the CHA 2 DS 2 -VASc and HAS-BLED Scores in Predicting the Risk of Stroke Versus Intracranial Bleeding in Patients with Atrial Fibrillation (From the FibStroke Study)

CHA2DS2-VASc and HAS-BLED scores stratify the risk of thromboembolic and bleeding events respectively in patients with atrial fibrillation. There is only little information on how they differentiate which of the 2 clinically most important complications (ischemic stroke [IS] or an intracranial bleeding [IB]) the patient is more prone to suffer. We evaluated both scores in patients with either of these major complications. The FibStroke Study collected data on all patients with atrial fibrillation with either an IS or an IB event between 2003 and 2012 in 4 Finnish hospital districts. Individual electronic patient records were manually reviewed to collect the study data. To assess the relative risk of IS and IB, an IS/IB-ratio was calculated by dividing the absolute number of ISs with the absolute number of IBs within each score category. A total of 3,816 (82.7%) ISs and 798 (17.3%) IBs were detected in 3,909 patients. In general, ISs occurred more often than IBs in patients on oral anticoagulation in each score category (ratio 1.6 to 5.1). The ratio decreased below 1, however, only with very high HAS-BLED scores (>4). Moreover, 221 ISs and 53 IBs occurred in patients with HAS-BLED > CHA2DS2-VASc, of whom only 19.7% were on anticoagulation. In conclusion, IS was the predominant intracranial event irrespective of CHA2DS2-VASc score, HAS-BLED score ≤4, or use of oral anticoagulation, also in patients with low estimated thromboembolic risk (CHA2DS2-VASc 0 to 1). Furthermore, the HAS-BLED score predicted the excess of IBs over ISs only at very high-risk levels.