Introduction

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia in Mexico.¹ It is associated with complications such as stroke, heart failure, and death.

Pulmonary vein isolation is a treatment option that prevents disease progression and prevents complications by restoring sinus rhythm.² Simultaneously, embolic events can be prevented with anticoagulation in most cases.

Thromboembolic prevention, guided by international recommendations, continues to be the first-line management. However, sometimes, the preventive benefit of anticoagulants is limited by the increased risk in the bleeding rate. In cases of high bleeding risk, occlusion of the left atrial appendage can be considered an alternative to anticoagulation in complex scenarios who are not candidates for long-term anticoagulation due to having a high risk of bleeding.

Case presentation

A male 69-years-old Latino with a history of intense smoking and a sedentary lifestyle underwent a subtotal colectomy in 2016 due to diagnosis of UC disease complicated with an episode of toxic megacolon. Since then, the patient has had episodes of intermittent rectorrhagia. In February 2023, the patient noted the presence of a parasternal hernia; during pre-surgical protocol for hernia repair, an atrial fibrillation rhythm was found. Following the current guidelines, antiarrhythmic medication and oral anticoagulation were started. However, the patient failed to return to sinus rhythm and developed gastrointestinal bleeding due to management, with increased rectorrhagia, which requires admission to the hospital due to bleeding, so he was disregarded as a candidate for lifelong anticoagulation.

In trying to find the trigger and the substrate that triggered the arrhythmia, a non-obstructive CAD in the coronary computed tomography angiography was found, and in the transthoracic echocardiography the findings where a biauricular dilatation and a decreased atrial function, RV dilatation, PASP was 54 mmHg, LV diastolic dysfunction grade III, and preserved biventricular function, without areas of hypokinesia or akinesia - revealing atrial dilatation as the likely trigger.

Even though conventional scores showed a low-risk result, it was considered essential to revert to sinus rhythm due to the strong thrombotic component conditioned by the UC and the contraindication for anticoagulation. An electrophysiological study was performed, followed by cryoablation of the four pulmonary veins (Figures 1 and 2), without achieving sinus rhythm, so it was decided to perform non-success electrical cardioversion twice (200 joules). The intervention team decided to perform a wide antral circumferential ablation (WACA) with posterior wall and left atrial appendage isolation, thus successfully achieving arrhythmia jugulation. Due to the hindrance of anticoagulation, after the left atrial appendage isolation, a closure device was placed in the left atrial appendage (Figures 2 and 3). After three months of optimal medical management with apixaban and amiodarone, the patient remained in sinus rhythm, and anticoagulation was discontinued. The patient is free of thrombotic and bleeding events for more than one year after the procedure and after stopping the anticoagulant.

Figure 1: A-D) Cryoablation sequence of the four pulmonary veins. E) Cryoablation of the left atrial appendage after failed cardioversion. 

Figure 2: Transesophageal echocardiogram sequence of procedure. A) Transeptal puncture. B) Left atrial appendage ablation. C, D) Positioning of left atrial appendage closure device. 

Figure 3: Atrial appendage closure device sequence. A) Approach. B) Placement. C) Release. 

Discussion

Cryoablation of pulmonary veins is a well-studied and effective treatment strategy for patients with atrial fibrillation. Nevertheless, there is always the possibility of procedural failure or recurrence of arrhythmia. In our patient, the arrhythmogenic substrate was in the left atrial appendage. After isolation, the arrhythmia stopped at a site with low incidence reported in the literature. In these scenarios, wide ablation techniques should be used and the search should be expanded to include structures outside the pulmonary veins.² However, previous studies have demonstrated its potential arrhythmic capacity.³ Therefore, catheter ablation of the posterior wall and left atrial appendage has emerged as an option to increase therapeutic efficacy and improve outcomes in patients with persistent AF originating outside the pulmonary veins.⁴,⁵ It has been suggested that there is a substantial risk of thrombus in those undergoing left atrial appendage isolation, so patients undergoing isolation usually also require LAAC.²

This case highlights that anticoagulation given to reduce the risk of stroke carries the burden of an increased risk of bleeding, so finding the right balance is crucial. In patients with atrial fibrillation and high bleeding scores, which also have a high thromboembolic risk due to the thrombotic inflammation and immunothrombosis state by chronic diseases, another alternative must be sought.⁶-⁸ In complex scenarios with a high bleeding risk, occlusion of the left atrial appendage can be considered as an alternative to anticoagulation in those who are not candidates for long-term. In the Prague-17 trial, the use of the left appendage closure device has demonstrated non-inferiority compared to oral anticoagulation to prevent stroke, consistent with what has been reported by studies PROTECT AF and PREVAIL.²,⁹

In this case of ulcerative colitis and persistent atrial fibrillation with failed electric cardioversion, cryoablation of pulmonary veins, and WACA, including left atrial appendage before the placement of an occlusion device resulted in an effective strategy for rhythm control and stroke prevention. Current guidelines support the use of atrial appendage closure devices with a cautious level of recommendation in selected patients, particularly in cases such as this, where the use of anticoagulation is prohibitive.¹⁰ However, in complex scenarios, it is an extremely useful tool, and its use is growing exponentially.

Conclusions

This case demonstrates the importance of individualizing the approach in a patient at high risk of thrombotic and bleeding events, where the appendage closure device is a good treatment strategy. In addition, cryoballoon ablation of the left atrial appendage and left posterior wall ablation are innovative techniques with few reported cases and were critical to the successful management of our patient.