The left atrial appendage closure by surgery 2 trial: statistical analysis plan for a randomized multicenter trial exploring if the closure of the left atrial appendage during open-heart surgery reduces stroke irrespective of patients' stroke risk and preoperative atrial fibrillation status.

BACKGROUND: Surgical left atrial appendage (LAA) closure concomitant to open-heart surgery prevents thromboembolism in high-risk patients. Nevertheless, high-level evidence does not exist for LAA closure performed in patients with any CHA2DS2-VASc score and preoperative atrial fibrillation or flutter (AF) status-the current trial attempts to provide such evidence. METHODS: The study is designed as a randomized, open-label, blinded outcome assessor, multicenter trial of adult patients undergoing first-time elective open-heart surgery. Patients with and without AF and any CHA2DS2-VASc score will be enrolled. The primary exclusion criteria are planned LAA closure, planned AF ablation, or ongoing endocarditis. Before randomization, a three-step stratification process will sort patients by site, surgery type, and preoperative or expected oral anticoagulation treatment. Patients will undergo balanced randomization (1:1) to LAA closure on top of the planned cardiac surgery or standard care. Block sizes vary from 8 to 16. Neurologists blinded to randomization will adjudicate the primary outcome of stroke, including transient ischemic attack (TIA). The secondary outcomes include a composite outcome of stroke, including TIA, and silent cerebral infarcts, an outcome of ischemic stroke, including TIA, and a composite outcome of stroke and all-cause mortality. LAA closure is expected to provide a 60% relative risk reduction. In total, 1500 patients will be randomized and followed for 2 years. DISCUSSION: The trial is expected to help form future guidelines within surgical LAA closure. This statistical analysis plan ensures transparency of analyses and limits potential reporting biases. TRIAL REGISTRATION: Clinicaltrials.gov, NCT03724318. Registered 26 October 2018, https://clinicaltrials.gov/study/NCT03724318 . PROTOCOL VERSION: https://doi.org/10.1016/j.ahj.2023.06.003 .

The left atrial appendage closure by surgery-2 (LAACS-2) trial protocol rationale and design of a randomized multicenter trial investigating if left atrial appendage closure prevents stroke in patients undergoing open-heart surgery irrespective of preoperative atrial fibrillation status and stroke risk.

BACKGROUND: Current recommendations regarding the use of surgical left atrial appendage (LAA) closure to prevent thromboembolisms lack high-level evidence. Patients undergoing open-heart surgery often have several cardiovascular risk factors and a high occurrence of postoperative atrial fibrillation (AF)-with a high recurrence rate-and are thus at a high risk of stroke. Therefore, we hypothesized that concomitant LAA closure during open-heart surgery will reduce mid-term risk of stroke independently of preoperative AF status and CHA2DS2-VASc score. METHODS: This protocol describes a randomized multicenter trial. Consecutive participants ≥18 years scheduled for first-time planned open-heart surgery from cardiac surgery centers in Denmark, Spain, and Sweden are included. Both patients with a previous diagnosis of paroxysmal or chronic AF, as well as those without AF, are eligible to participate, irrespective of their CHA2DS2-VASc score. Patients already planned for ablation or LAA closure during surgery, with current endocarditis, or where follow-up is not possible are considered noneligible. Patients are stratified by site, surgery type, and preoperative or planned oral anticoagulation treatment. Subsequently, patients are randomized 1:1 to either concomitant LAA closure or standard care (ie, open LAA). The primary outcome is stroke, including transient ischemic attack, as assigned by 2 independent neurologists blinded to the treatment allocation. To recognize a 60% relative risk reduction of the primary outcome with LAA closure, 1,500 patients are randomized and followed for 2 years (significance level of 0.05 and power of 90%). CONCLUSIONS: The LAACS-2 trial is likely to impact the LAA closure approach in most patients undergoing open-heart surgery. TRIAL REGISTRATION: NCT03724318.

Randomized Trial of Surgical Left Atrial Appendage Closure: Protection Against Cerebrovascular Events.

Following open-heart surgery, atrial fibrillation and stroke occur frequently. Left atrial appendage closure added to elective open-heart surgery could reduce the risk of ischemic stroke. We aim to examine if routine closure of the left atrial appendage in patients undergoing open-heart surgery provides long-term protection against cerebrovascular events independently of atrial fibrillation history, stroke risk, and oral anticoagulation use. Long-term follow-up of patients enrolled in the prospective, randomized, open-label, blinded evaluation trial entitled left atrial appendage closure by surgery (NCT02378116). Patients were stratified by oral anticoagulation status and randomized (1:1) to left atrial appendage closure in addition to elective open-heart surgery vs standard care. The primary composite endpoint was ischemic stroke events, transient ischemic attacks, and imaging findings of silent cerebral ischemic lesions. Two neurologists blinded for treatment assignment adjudicated cerebrovascular events. In total, 186 patients (82% males) were reviewed. At baseline, mean (standard deviation (SD)) age was68 (9) years and 13.4% (n = 25/186) had been diagnosed with atrial fibrillation. Median [interquartile range (IQR)] CHA2DS2-VASc was 3 [2,4] and 25.9% (n = 48/186) were receiving oral anticoagulants. Mean follow-up was 6.2 (2.5) years. The left atrial appendage closure group experienced fewer cerebrovascular events; intention-to-treat 11 vs 19 (P = 0.033, n = 186) and per-protocol 9 vs 17 (P = 0.186, n = 141). Left atrial appendage closure as an add-on open-heart surgery, regardless of pre-surgery atrial fibrillation and oral anticoagulation status, seems safe and may reduce cerebrovascular events in long-term follow-up. More extensive randomized clinical trials investigating left atrial appendage closure in patients without atrial fibrillation and high stroke risk are warranted.

New-onset of postoperative atrial fibrillation is likely to recur in the absence of other triggers.

BACKGROUND: Incident atrial fibrillation (AF) is reported in 10%-65% of patients without previous AF diagnosis after open heart surgery. The risk of late AF recurrence after a postoperative AF onset is unclear, and it is controversial whether AF limited to the postoperative period should elicit oral anticoagulation (OAC) therapy. The primary objective of this study was to evaluate the long-term recurrence of AF in patients developing new-onset peri-procedural AF. PATIENTS AND METHODS: Patients (n=189) with available baseline and follow-up data included in Left Atrial Appendage Closure with Surgery trial were coded for known AF at baseline and for postoperative first-time AF diagnosis. AF occurrence was classified as follows: peri-procedural ≤7 days postoperatively, early >7 days but ≤3 months and late >3 months. Patients with no AF recurrence registered during follow-up were invited to undergo Holter monitoring. RESULTS: A total of 163 (86.2%) patients had no history of AF. Among these, 80 (49.1%) developed new-onset peri-procedural AF. After a mean follow-up of 3.7±1.6 years, late AF occurred in 35 of the 80 (43.8%) patients who developed peri-procedural AF and in 6 additional patients (7.2%) who remained in sinus rhythm until discharge (hazard ratio [HR] 9.3, 95% CI 3.8-22.4, p<0.001). Patients with peri-procedural AF and early AF had 12.24 times higher risk of late AF (95% CI 4.76-31.45, p<0.001) as compared to the group with no postoperative AF. CONCLUSION: New-onset of AF after open heart surgery has a high rate of recurrence and should not be regarded as a self-limiting phenomenon secondary to surgery.

Does Left Atrial Appendage Amputation During Routine Cardiac Surgery Reduce Future Atrial Fibrillation and Stroke?

PURPOSE OF REVIEW: Stroke is the most feared complication of atrial fibrillation. To prevent stroke, left atrial appendage exclusion has been targeted, as it is the prevalent site for formation of heart thrombi during atrial fibrillation. We review the historic development of methods for exclusion of the left atrial appendage and the evidence to support its amputation during routine cardiac surgery. RECENT FINDINGS: Evidence is not yet sufficient to routinely recommend left atrial exclusion during heart surgery, despite a high prevalence of postoperative atrial fibrillation. Observational studies indicate that electrical isolation of scarring from clip or suture techniques reduces the arrhythmogenic substrate. Randomized studies comparing different methods of closure of the left atrial appendage before amputation do not exist. Such studies are therefore warranted, as well as studies that can elucidate whether amputation is superior to leaving the left atrial appendage stump. Potentially, thrombogenic remaining pouch after closure should be addressed.

Adding left atrial appendage closure to open heart surgery provides protection from ischemic brain injury six years after surgery independently of atrial fibrillation history: the LAACS randomized study.

BACKGROUND: Open heart surgery is associated with high occurrence of atrial fibrillation (AF), subsequently increasing the risk of post-operative ischemic stroke. Concomitant with open heart surgery, a cardiac ablation procedure is commonly performed in patients with known AF, often followed by left atrial appendage closure with surgery (LAACS). However, the protective effect of LAACS on the risk of cerebral ischemia following cardiac surgery remains controversial. We have studied whether LAACS in addition to open heart surgery protects against post-operative ischemic brain injury regardless of a previous AF diagnosis. METHODS: One hundred eighty-seven patients scheduled for open heart surgery were enrolled in a prospective, open-label clinical trial and randomized to concomitant LAACS vs. standard care. Randomization was stratified by usage of oral anticoagulation (OAC) planned to last at least 3 months after surgery. The primary endpoint was a composite of post-operative symptomatic ischemic stroke, transient ischemic attack or imaging findings of silent cerebral ischemic (SCI) lesions. RESULTS: During a mean follow-up of 3.7 years, 14 (16%) primary events occurred among patients receiving standard surgery vs. 5 (5%) in the group randomized to additional LAACS (hazard ratio 0.3; 95% CI: 0.1-0.8, p = 0.02). In per protocol analysis (n = 141), 14 (18%) primary events occurred in the control group vs. 4 (6%) in the LAACS group (hazard ratio 0.3; 95% CI: 0.1-1.0, p = 0.05). CONCLUSIONS: In a real-world setting, LAACS in addition to elective open-heart surgery was associated with lower risk of post-operative ischemic brain injury. The protective effect was not conditional on AF/OAC status at baseline. TRIAL REGISTRATION: LAACS study, clinicaltrials.gov NCT02378116 , March 4th 2015, retrospectively registered.