Reduced Incidence of Thromboembolic Events after Surgical Closure of Left Atrial Appendage in Patients with Atrial Fibrillation

Systematic review and meta-analysis of left atrial appendage closure's influence on early and long-term mortality and stroke

Objective

Left atrial appendage closure (LAAC) concomitant to heart surgery in patients with underlying atrial fibrillation (AF) has gained attention because of long-term reduction of thromboembolic complications. As of mortality benefits in the setting of non-AF, data from both observational studies and randomized controlled trials are conflicting.

Methods

On-line databases were screened for studies comparing LAAC versus no LAAC concomitant to other heart surgery. End points assessed were all-cause mortality and stroke at early and longest-available follow-up. Subgroup analyses stratified on preoperative AF were performed. Risk ratios (RR) with 95% CIs served as primary statistics.

Results

Electronic search yielded 25 studies (N = 660 [158 patients]). There was no difference between LAAC and no LAAC in terms of early mortality. In the overall population analysis, LAAC reduced long-term mortality (RR, 0.86; 95% CI, 0.74-1.00; P = .05; I 2 = 88%), reduced early stroke risk by 19% (RR, 0.81; 95% CI, 0.72-0.93; P = .002; I 2 = 57%), and reduced late stroke risk by 13% (RR, 0.87; 95% CI, 0.84-0.90; P < .001; I 2 = 58%). Subgroup analysis showed lower mortality (RR, 0.85; 95% CI, 0.72-1.01; P = .06; I 2 = 91%), short-, and long-term stroke risk reduction only in patients with preoperative AF (RR, 0.81; 95% CI, 0.71-0.93; P = .003; I 2 = 71% and RR, 0.87; 95% CI, 0.84-0.91; P < .001; I 2 = 70%, respectively). No benefit of LAAC in patients without AF was found.

Conclusions

Concomitant LAAC was associated with reduced stroke rates at early and long-term and possibly reduced all-cause mortality at the long-term follow-up but the benefits were limited to patients with preoperative AF. There is not enough evidence to support routine concomitant LAAC in non-AF settings.

Left Atrial Appendage Amputation for Atrial Fibrillation during Aortic Valve Replacement

BACKGROUND

Occluding the left atrial appendage (LAA) during cardiac surgery reduces the risk of ischemic stroke; nonetheless, it is currently only softly recommended with "may be considered" by the current guidelines. We aimed to assess thromboembolic risk after LAA amputation in patients with atrial fibrillation (AF) and aortic stenosis undergoing biological aortic valve replacement (AVR) as primary cardiac surgery.

METHODS

Two cohorts were generated retrospectively: patients with AF undergoing AVR alone or combined with revascularization either with LAA amputation or without. Data were collected from the hospital-specific data system. Follow-up was completed by telephone interview or in person. Thirty-day and follow-up results were compared in patients with vs. without LAA amputation.

RESULTS

One hundred and fifty-seven patients were investigated retrospectively, and seventy-four pairs were matched with regard to baseline characteristics. Patients with LAA amputation exhibited a lower incidence of cumulative and late ischemic stroke (6.4% vs. 25%, p = 0.028 and 3.2% vs. 20%, p = 0.008, respectively; hazard ratio 0.30; 95% confidence interval 0.11; 0.84; p = 0.021) during follow-up of 48 months vs. patients without intervention during follow-up of 45 months, p = 0.494. No significant differences were observed in postoperative stroke, 2 (2.7%) vs. 3 (4.1%), p = 1.000, re-exploration for bleeding 3 (4.1%) vs. 6 (8.1), p = 0.494 or late pericardial effusion 2 (2.7%) vs. 3 (4.1%), p = 1.000, in-hospital 2 (2.7%) vs. 4 (5.4%), p = 0.681 and all-cause mortality 15 (23.8%) vs. 9 (15%), p = 0.315 in patients with vs. without LAA amputation, respectively.

CONCLUSIONS

A combination of leading aortic stenosis and AF in patients undergoing isolated or combined biological AVR represents a subpopulation with excessive thromboembolic risk. Concomitant LAA amputation during cardiac surgery reduces the risk of ischemic stroke without posing an additional periprocedural risk for the patient. Therefore, the minimal invasive approach at the expense of omitting LAA amputation should be discouraged to maximize the clinical benefits of AVR in this setting.

Left atrial appendage closure during cardiac surgery for atrial fibrillation: A meta-analysis

BACKGROUND

Left atrial appendage closure (LAAC) during cardiac surgery in atrial fibrillation (AF) patients has been investigated in multiple studies with variable safety and efficacy results.

METHODS

A comprehensive review was performed of all studies comparing LAAC and placebo arm during cardiac surgery in AF patients. A random-effect model was used to calculate risk ratios, mean differences, and 95% confidence intervals.

RESULTS

Five randomized controlled trials and 22 observational studies were included with a total of 540,111 patients. The LAAC group had significantly decreased postoperative stroke/embolic events as compared to the no LAAC group with all cardiac surgeries (3.74% vs 4.88%, p = 0.0002), isolated valvular surgery (1.95% vs 4.48%, p = 0.002). However, CABG insignificantly favored the LAAC group for stroke/embolic events (6.72% vs 8.30%, p = 0.07). There was no difference between both groups in all-cause mortality in the perioperative period (p = 0.42), but was significantly lower in the LAAC arm after two years (14.1% vs 18.3%, p = 0.02). There was no difference in major bleeding, all-cause rehospitalizations, or cross-clamp time between both groups (p = 0.53 and p = 0.45). The bypass and the cross-clamp time were longer in the LAAC group (4 and 9 min, respectively).

CONCLUSION

In AF patients, LAAC during cardiac surgery had a decreased risk of stroke and long-term all-cause mortality. Additionally, there was no difference in major bleeding, all-cause rehospitalizations, or cross-clamp time.

Beneficial effect of left atrial appendage closure during cardiac surgery: a meta-analysis of 280 585 patients

In non-rheumatic atrial fibrillation (AF), left atrial appendage (LAA) is thought to be the source of embolism in 90% of the strokes. Thus, as recent clinical trials have shown the non-inferiority of percutaneous LAA closure (LAAc) in comparison to medical treatment, and despite a IIb recommendation in the latest guidelines for concomitant surgical LAAc, we sought to investigate the beneficial effect of LAAc in the surgical population. A meta-analysis model was performed comparing studies including any cardiac surgery with or without concomitant surgical LAAc reporting stoke/embolic events and/or mortality, from inception to January 2019. Twenty-two studies (280 585 patients) were included in the model. Stroke/embolic events both in the perioperative period [relative risk (RR) 0.66, 95% confidence interval (CI) 0.53–0.82; P = 0.0001] and during follow-up of >2 years (RR 0.67, 95% CI 0.51–0.89; P < 0.005) were significantly reduced in patients who underwent surgical LAAc (RR 0.71, 95% CI 0.58–0.87; P = 0.001). Regarding the rate of preoperative AF, LAAc showed protective effect against stroke/embolic events in studies with >70% preoperative AF (RR 0.64, 95% CI 0.53–0.77; P < 0.00001) but no benefit in the studies with <30% of preoperative AF (RR 0.77, 95% CI 0.46–1.28; P = 0.31). Postoperative mortality was also significantly lower in surgical patients with LAAc at the mid- and long-term follow-up. (RR 0.72, 95% CI 0.67–0.78; P < 0.00001; I2 = 0%). Based on these findings, concomitant surgical LAAc is associated with lower rates of embolic events and stroke in the postoperative period in patients with preoperative AF and also improves postoperative mortality in the mid- and long-term follow-up.

Concomitant surgical closure of left atrial appendage: A systematic review and meta-analysis

OBJECTIVES

Although percutaneous closure of the left atrial appendage is supported as a potential alternative to lifelong anticoagulation in patients with atrial fibrillation, comprehensive evidence on surgical left atrial appendage closure in heart surgery is limited.

METHODS

We conducted a meta-analysis of studies comparing patients who underwent open cardiac surgery with or without left atrial appendage closure. A literature search was performed on PubMed, Embase, and Cochrane Trials databases. Outcomes of interest were 30-day/in-hospital mortality and cerebrovascular accident. I² statistics were used to evaluate heterogeneity, and publication bias was evaluated by Begg's and Egger's tests.

RESULTS

We reviewed 1284 articles and selected for main analysis 7 articles including 3897 patients (1963 in the left atrial appendage closure group and 1934 in the non-left atrial appendage closure group). Among the 7 studies, 3 were randomized-controlled studies, 3 were propensity-matched studies, and 1 was a case-matching study. At 30-day/in-hospital follow-up, left atrial appendage closure was significantly associated with decreased risk of mortality and cerebrovascular accident (odds ratio, 0.384, 95% confidence interval, 0.233-0.631 for mortality, and odds ratio, 0.622, 95% confidence interval, 0.388-0.998 for cerebrovascular accident). Stratified analysis demonstrated that this association was more prominent in preoperative atrial fibrillation strata.

CONCLUSIONS

Concomitant surgical left atrial appendage closure should be considered at the time of open cardiac surgery, particularly among those in atrial fibrillation preoperatively. The benefit of left atrial appendage closure for patients not in atrial fibrillation and for those undergoing nonvalvular surgery is still unclear. Further prospective investigations are indicated.