Thromboembolic and bleeding complications after elective cardioversion of atrial fibrillation: a nationwide cohort study

AIMS

Elective cardioversion (ECV) is routinely used in atrial fibrillation (AF) to restore sinus rhythm. However, it includes a risk of thromboembolism even during adequate oral anticoagulation treatment. The aim of this study was to evaluate the risk of thromboembolic and bleeding complications after ECV in a real-life setting utilizing data from a large AF population.

METHODS AND RESULTS

This nationwide register-based study included all (n = 9625) Finnish AF patients undergoing their first-ever ECV between 2012 and 2018. The thromboembolic and bleeding complications within 30 days after ECV were analysed. The mean age of the patients was 67.7 ± 9.9 years, 61.2% were men, and the mean CHA2DS2-VASc score was 2.6 ± 1.6. Warfarin was used in 6245 (64.9%) and non-vitamin K oral anticoagulants (NOACs) in 3380 (35.1%) cardioversions. Fifty-two (0.5%) thromboembolic complications occurred, of which 62% were ischaemic strokes, 25% transient ischaemic attacks, and 13% other systemic embolisms. Thromboembolic events occurred in 14 (0.4%) NOAC-treated patients and in 38 (0.6%) warfarin-treated patients (odds ratio 0.77; confidence interval: 0.42-1.39). The median time from ECV to the thromboembolic event was 2 days, and 78% of the events occurred within 10 days. Age and alcohol abuse were significant predictors of thromboembolic events. Among warfarin users, thromboembolic complications were more common with international normalized ratio (INR) <2.5 than INR ≥2.5 (0.9% vs. 0.4%, P = 0.026). Overall, 27 (0.3%) bleeding events occurred.

CONCLUSION

The rate of thromboembolic and bleeding complications related to ECV was low without significant difference between NOAC- and warfarin-treated patients. With warfarin, INR ≥2.5 at the time of cardioversion reduced the risk of thromboembolic complications.

Are Three Weeks of Oral Anticoagulation Sufficient for Safe Cardioversion in Atrial Fibrillation?

Background and Objectives: Patients with atrial fibrillation (AF), lasting >48 h, considered for cardioversion, are recommended ≥3 weeks of oral anticoagulation before sinus rhythm restoration because of high risk of development of left atrial thrombosis (LAT) and stroke. However, the optimal duration of anticoagulation in the presence of overt LAT is unknown. Materials and Methods: An open-label study aimed to investigate the prevalence of spontaneous echo contrast (SEC) and LAT before and after 3 weeks of direct oral anticoagulant (DOAC) treatment. We included 51 consecutive patients (50.9% males), mean age 69.3 ± 7.4 years with paroxysmal/unknown duration of AF, considered for cardioversion, who agreed to have transesophageal echocardiography at enrollment and 3 weeks later. Results: At baseline SEC was present in 26 (50.9%) and LAT in 10 (19.6%) of 51 patients. After 3 weeks on DOAC, SEC persisted in 12 (25.0%) and LAT in 7 (14.5%) of 48 patients, p < 0.05 vs. baseline. Factors, associated most strongly with persistence of SEC/LAT, were left atrial appendage (LAA) emptying velocity <20 cm/s (OR = 2.82), LAA lobes >2 (OR = 1.84), and indexed left atrial volume ≥34 mL/m² (OR = 1.37). Conclusions: In our study the incidence of SEC/LAT, particularly in AF with unknown duration, was not as low as we expected. The prevalence of SEC/LAT seemed to be dependent on factors not routinely evaluated in AF patients planned for cardioversion (indexed LA volume, LAA morphology and number of lobules, LAA emptying velocity, etc.). Our data suggested an individualized approach for DOAC duration in AF patients before an attempt for restoration of sinus rhythm is made, taking into consideration the LAA morphology and function.

Efficacy and safety of direct oral anticoagulants in patients undergoing elective electrical cardioversion: A real-world patient population

BACKGROUND

Direct oral anticoagulants (DOACs) have emerged as the preferred choice of oral anticoagulation in patients with atrial fibrillation. Randomized trials have demonstrated the efficacy and safety of DOAC in patients undergoing electrical cardioversion (ECV); however, there is limited real-world data.

OBJECTIVE

To evaluate the outcome of patients undergoing an elective ECV for atrial tachyarrhythmia in a tertiary referral center who were treated with DOAC or vitamin K antagonist (VKA) without routine trans esophageal echocardiography (TEE).

METHODS

This was a retrospective single-center cohort study of consecutive patients undergoing an elective ECV for atrial tachyarrhythmia from January 2013 to February 2020. The primary endpoints were thromboembolism (composite of stroke, transient ischemic attack or systemic embolism) and major bleeding events within 60 days.

RESULTS

A total of 1431 ECV procedures were performed in 920 patients. One-third of the procedures were performed under DOAC (N = 488, 34%) and the remainder of the procedures was performed under VKA (N = 943, 66%). There were no differences between groups with regard to demographic variables (mean age 62.4 ± 11.7, 72% men) and mean CHA₂DS₂-VASc score (2.3 ± 1.6); however, the VKA group had a higher proportion of patients with co-morbidity. Thromboembolism occurred in 0.41% in the DOAC group versus 0.64% in the VKA group (P = 0.72). Major bleeding events occurred in 0.41% in the DOAC group versus 0.11% in the VKA group (P = 0.27).

CONCLUSION

In a real-world population, the rates of thromboembolism and major bleeding events were low after elective ECV in patients using DOAC or VKA, even without routine TEE.

Efficacy and safety of dabigatran in patients with atrial fibrillation scheduled for transoesophageal echocardiogram-guided direct electrical current cardioversion: a prospective propensity score-matched cohort study

Patients with atrial fibrillation (AF) are predisposed to a hypercoagulable state and are at an increased risk for thromboembolic events when undergoing procedures. This study investigated the long-term efficacy and safety of newly initiated anticoagulation with dabigatran versus uninterrupted vitamin K antagonist (VKA) therapy in patients with AF scheduled for transesophageal echocardiogram (TEE)-guided direct electrical current cardioversion (DCC). Consecutive adult patients with persistent AF scheduled to undergo DCC were included in the study. Patients received dabigatran 110 mg or 150 mg twice daily (bid) or VKA at therapeutic doses for at least 3 weeks before and 4 weeks after DCC. All patients underwent anamnestic, clinical, electrocardiographic and echocardiographic evaluation at each follow-up visit, and were followed up for a total period of 2 years. The primary efficacy outcome was the composite of stroke/transient ischaemic attack and systemic embolism. The primary safety outcome was major bleeding. 176 patients receiving dabigatran (77% dabigatran 150 mg bid) were propensity score-matched to 176 patients on VKA therapy. A low incidence of atrial thrombus (0.6%) at TEE was found in both groups (0.6%). The acute cardioversion success rate was 85.1% in the dabigatran group (149/175) and 83.4% in the VKA group (146/175). During the follow-up period, a similar low incidence of thromboembolic events (0.6%) was reported in both groups; the bleeding safety profile tended to favour dabigatran over VKA (1.1% vs 1.7%; P = 0.3). Newly initiated anticoagulation with dabigatran in patients with nonvalvular AF scheduled for TEE-guided DCC seems to be as effective and safe as uninterrupted VKA therapy, during long-term follow up.

Direct Oral Anticoagulants in Cardioversion: A Review of Current Evidence

OBJECTIVE

Direct oral anticoagulants (DOACs) are recommended for the prevention of stroke or systemic embolism in nonvalvular atrial fibrillation. Dabigatran, rivaroxaban, apixaban, and edoxaban represent possible alternatives to warfarin in the setting of cardioversion. A literature review was conducted to evaluate the safety and efficacy of DOAC use pericardioversion.

DATA SOURCES

A PubMed and MEDLINE search through August 2017 was conducted using the following search terms alone or in various combinations: dabigatran, rivaroxaban, apixaban, edoxaban, betrixaban, DOAC, NOAC, TSOAC, cardioversion.

STUDY SELECTION AND DATA EXTRACTION

All English-language, human studies comparing the safety and efficacy of DOACs with that of other anticoagulants in the setting of cardioversion were eligible for inclusion. References from published articles were reviewed for additional relevant citations for study inclusion. Four retrospective and 2 prospective trials comparing DOACs with warfarin were identified.

DATA SYNTHESIS

The majority of studies included patients undergoing electric cardioversion. Based on current evidence, the DOACs perform similarly to warfarin in the prevention of stroke and systemic embolism, and bleeding rates are comparable.

CONCLUSIONS

DOACs may be an attractive alternative to warfarin because of fast onset of action, potentially reducing delay to cardioversion. More robust studies are needed in patients with renal dysfunction and patients undergoing pharmacological cardioversion.

Findings of transoesophageal echocardiogram in appropriately anticoagulated patients with persistent atrial fibrillation prior to planned cardioversion

Background

To evaluate a diagnostic value of transoesophageal echocardiogram (TEE) in appropriately anticoagulated patients with a non-valvular atrial fibrillation (AF) and to establish possible additional indications for TEE; to evaluate the incidence of left atrial (LA) thrombi in appropriately anticoagulated patients in daily clinical practice.

Methods

This retrospective study analyses data of 432 patients who had been anticoagulated by means of oral anticoagulants (OACs) prior to planned cardioversion during the period from 2012 to 2015. Thromboembolic (TE) and bleeding risks were assessed using CHA2DS2-VASc and HAS-BLED scores. Transthoracic and transoesophageal echocardiograms were evaluated. TE complications during 30 days after discharge were assessed.

Results

432 patients were selected, aged from 22 to 89 years (mean 65.0 ±11.5), 277 (64.1%) males and 155 (35.9%) females, 306 (70.8%) on warfarin and 126 (29.2%) on non-vitamin K antagonist oral anticoagulants (NOAC). Mean CHA2DS2-VASc score was 3.5 ±1.5. TEE was performed for 120 (27.8%) patients, more frequently for patients on NOACs and for ones with III° LA enlargement.

TEE revealed LA thrombi in seven (5.8%) of the patients. In warfarin and NOACs groups thrombi were revealed in five (7.0%) and two (4.1%) patients, respectively. TEE did not reveal any thrombi in patients with normal left ventricular (LV) function; however, thrombi were found in two (6.1%) patients with slightly decreased LV function, and in five (17.9%) patients with markedly decreased LV function.

In patients with decreased left ventricular ejection fraction (LVEF) thrombi in LA were found more frequently than in patients with normal and slightly decreased LVEF (17.9% vs 2.2%, p=0.008). CHA2DS2-VASc score of all 7 patients was ≥5. None of the patients after cardioversion had TE complications 30 days after discharge.

Conclusions

The risk of LA thrombi in patients prepared for scheduled cardioversion in line with the guidelines is low. Higher risk of thrombi was present in patients with decreased LVEF (≤40%), CHA2DS2-VASc ≥5. In order to assess more accurately indications to perform TEE for appropriately anticoagulated patients prior to scheduled cardioversion a study with larger number of patients is required.

Practical Implementation of Anticoagulation Strategy for Patients Undergoing Cardioversion of Atrial Fibrillation

Anticoagulation is routinely prescribed to patients with persistent AF before cardioversion to reduce the risk of thromboembolic events. As direct oral anticoagulants (DOACs) have a rapid onset of action, a consistent anticoagulant effect, if taken correctly, and do not need monitoring or dose adjustments, there is considerable interest in their use for patients with AF undergoing cardioversion. Post-hoc analyses show that DOACs are safe to use prior to and following cardioversion. In addition, two randomised controlled trials, X-VeRT and ENSURE-AF, have demonstrated the efficacy and safety of the DOACs rivaroxaban and edoxaban, respectively, in this setting. The use of DOACs allows cardioversions to be performed promptly and reduces the number of cancelled procedures compared with the use of warfarin.