Frequency of cardioversions as an additional risk factor for stroke in atrial fibrillation - the FinCV-4 study

Ann Med. 2022 Dec;54(1):1452-1458. doi: 10.1080/07853890.2022.2077430.

Abstract

Background: Patients with atrial fibrillation (AF) are selected for oral anticoagulation based on individual patient characteristics. There is little information on how clinical AF burden associates with the risk of ischaemic stroke or systemic embolism (SSE). The aim of this study was to explore the association of the frequency of cardioversions (CV) as a measure of clinical AF burden on the long-term SSE risk, with a focus on patients at intermediate stroke risk based on CHA2DS2-VASc score. For these patients, additional SSE risk stratification by assessing CV frequency may aid in the decision on whether to initiate oral anticoagulation.

Methods: This retrospective analysis of FinCV Study from years 2003-2010 included 2074 patients who were not using any oral anticoagulation (long term or temporary) after CVs and undergoing a total of 6534 CVs for AF from emergency departments of three hospitals. Two study groups were formed: high CV frequency (mean interval between CVs ≤12 months and low frequency (>12 months).

Results: A total of 107 SSEs occurred during a mean follow-up of 5.4 years. The event rates per 100 patient-years were 1.82 and 0.67 in high versus low CV frequency groups, respectively. After adjustment for CHA2DS2-VASc score, CV frequency independently predicted SSE (HR, 2.87 [95% CI, 1.47 to 5.64]; p = .002) at 3 years. Competing risk analysis also identified CV frequency (sHR, 2.70 [95% CI, 1.38-5.31]; p = .004) as an independent predictor for SSE. In patients with CHA2DS2-VASc score 1 and low CV frequency, the SSE risk was only 0.08 per 100 patient-years.

Conclusions: Frequency of CVs for symptomatic AF episodes provides additional information on stroke risk in AF patients with CHA2DS2-VASc score 1.Key messagesThis retrospective study offers a unique opportunity to observe the natural course of AF patients with infrequent episodes of clinical arrhythmia when they were not using OAC (before introduction of CHA2DS2-VASc score).Stroke or systemic embolism rate was very low (0.08 per 100 patient-years) in patients with one CHA2DS2-VASc point who visited the emergency room for cardioversion less than once a year.Frequency of cardioversions can be used for additional risk stratification in patients at intermediate risk of stroke based on CHA2DS2-VASc score.

Keywords: Atrial fibrillation; cardioversion; stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anticoagulants / therapeutic use
  • Atrial Fibrillation* / complications
  • Atrial Fibrillation* / epidemiology
  • Brain Ischemia* / epidemiology
  • Brain Ischemia* / etiology
  • Brain Ischemia* / prevention & control
  • Electric Countershock / adverse effects
  • Humans
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Stroke* / epidemiology
  • Stroke* / etiology
  • Stroke* / prevention & control

Substances

  • Anticoagulants

Grants and funding

Samuli Jaakkola: State Clinical Research Fund of Turku University Hospital, Turku, Finland; lectures for MSD, Boehringer-Ingelheim, Orion Pharma, BMS-Pfizer, Bayer, AstraZeneca. Tuomas O. Kiviniemi: research grants from the Finnish Foundation for Cardiovascular Research, Finnish Medical Foundation, State Clinical Research Fund of Turku University Hospital, Turku, Finland; lectures for Bayer, Boehringer Ingelheim, MSD, Astra Zeneca, and Bristol-Myers-Squibb-Pfizer; member of the advisory board of Boehringer-Ingelheim, and MSD. Jussi Jaakkola: None. Jussi-Pekka Pouru: received research grants from Turunmaa Duodecim Society, Finland, Doctoral Programme in Clinical Research, University of Turku, Finland, Aarne and Aili Turunen Foundation, Finland, Varsinais-Suomi Regional Fund, Finland, The Ida Montin Foundation, Finland, Turku University Foundation, Finland, The Maud Kuistila Memorial Foundation, Finland, and The Finnish Medical Foundation, Finland. Ilpo Nuotio: None. Tuija Vasankari: None. Juha E.K. Hartikainen: Research grants from the Finnish Foundation for Cardiovascular Research and the European Union Seventh Framework Programme. Lectures for Cardiome, St Jude Medical and Biotronic. Member in the advisory boards for Astra Zeneca, Amgen and Bayer. K.E. Juhani Airaksinen: Research grants from the Finnish Foundation for Cardiovascular Research and State Clinical Research Fund of Turku University Hospital, Turku, Finland. Lectures for Bayer, Bristol-Myers-Squibb-Pfizer and Boehringer Ingelheim. Member in the advisory boards for Bayer and Astra Zeneca. This work was supported by the Finnish Foundation for Cardiovascular Research, Helsinki, Finland, and Clinical Research Fund (EVO) of Turku University Hospital, Turku, Finland. The funding organisations had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.