The impact of surgical left atrial appendage amputation/ligation on stroke prevention in patients undergoing off-pump coronary artery bypass grafting

Efficacy of surgical ablation and left atrial appendage occlusion in patients with AF undergoing coronary artery bypass grafting: A network meta-analysis

BACKGROUND

Atrial fibrillation (AF) is a prevalent cardiac arrhythmia that greatly elevates the risk of stroke. This risk increases both during and after cardiac procedures, such as coronary artery bypass grafting (CABG). There is an increasing interest in non-pharmacological treatments such as left atrial appendage occlusion (LAAO) and surgical ablation, intending to enhance both immediate and long-term postoperative results.

OBJECTIVE

To investigate the efficacy of surgical ablation (SA), LAAO, or both in patients with AF undergoing CABG.

METHODS

We searched four electronic databases: PubMed, Scopus, Cochrane Library, and WOS. We analyzed data using R language and "netmeta" and "netrank" packages of meta-insight software. Pooled outcomes were reported as mean difference or risk ratio (RR) with 95 % confidence interval (CI) in a random effect method.

RESULTS

A total of 16 studies were included with 594,312 patients included. The 30-day mortality showed a non-statistically significant difference between CABG-LAAO compared to CABG alone and CABG-SA with RR of 1.70 (95%CI 0.38-7.61) and 0.62 (95%CI 0.10-3.94). However, compared to CABG alone, CABG-SA + LAAO, CABG-LAAO, and CABG-SA had significantly lower risk of long-term mortality with RR 0.75 (95%CI 0.57-0.98), 0.78 (95%CI 0.65-0.94), and 0.73 (95%CI 0.61-0.88), respectively. CABG-SA + LAAO, CABG-LAAO, and CABG-SA reduced the risk of short-term stroke compared to CABG alone with RR of 0.73 (95%CI 0.43-1.24), 0.93 (95%CI 0.78-1.11), and 1.01 (95%CI 0.75-1.36), respectively. Moreover, only CABG-SA + LAAO and CABG-LAAO showed a statistically significant reduction in long term stroke and hospitalization due to heart failure while CABG-SA showed no statistically significant difference. Furthermore, there was no statistically significant difference between our interventions in terms of 30-day rehospitalization, intra-aortic balloon pump support, and risk of hemorrhage.

CONCLUSION

Among patients with AF undergoing CABG, whether undergoing SA alone or LAAO alone or both showed significant clinical outcomes such as reduced risk of both short- and long-term mortality and short-term stroke.

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.

Routine left atrial appendage occlusion in patients undergoing cardiac surgery: a narrative review

PURPOSE OF REVIEW

New evidence suggests a greater prevalence of protracted postoperative atrial fibrillation (POAF) than previously recognized. The left atrial appendage (LAA) is the most common source of embolism in patients with nonvalvular atrial fibrillation. In this review, we ask whether there is evidence to support routine LAA occlusion (LAAO) in patients without preexisting atrial fibrillation undergoing cardiac surgery.

RECENT FINDINGS

Overall, available studies are small, inconsistent and have varying proportions of patients with and without preexisting atrial fibrillation. There is considerable discrepancy with respect to the efficacy of LAAO in reducing the risk of POAF-related stroke. Only one study reported a lower rate of stroke in the LAAO group compared with no LAAO. Two studies included a subgroup analysis of patients that developed POAF and report a significantly higher rate of stroke in patients that developed POAF and did not undergo LAAO. There are three clinical trials ongoing that are investigating prophylactic LAAO in patients undergoing cardiac surgery: ATLAS, LAA-CLOSURE and LAACS-2.

SUMMARY

There is currently insufficient evidence to recommend routine addition of LAAO to lower the risk of postoperative stroke. Ongoing clinical trials will provide important insight into the role of routine LAAO in all patients undergoing cardiac surgery.

Refinement of Coronary Artery Bypass Grafting at Juntendo University Hospital

Surgical treatment of ischemic heart disease began in 1945. After 1970, coronary artery bypass grafting (CABG) with cardiopulmonary bypass was developed along with coronary angiography. Juntendo University has been treating ischemic heart disease since 1980, and is actively performing off-pump CABG (OPCAB) since 2002. Besides the age of patients undergoing surgery, complications such as chronic hemodialysis, cerebrovascular disease, and malignancies make it challenging to reduce postoperative complications using OPCAB as graft preservation. OPCAB is technically challenging, and the CORONARY trial did not reveal its superiority over conventional CABG. Furthermore, high revascularization rates and technical differences among surgeons are important concerns. While not widely accepted in Europe and the United States, OPCAB comprises 65% of all stand-alone CABG in Japan. Japan reported a 2.5% hospital mortality rate in 2018, while the US reported 2.2% (according to the American Association of Thoracic Surgeons). In contrast, Juntendo University Hospital has maintained a 1% hospital mortality rate since 1984. To reduce the incidence of remote stroke in CABG patients, Juntendo has been using stroke-free management since 2010. Postoperative atrial fibrillation is 4-5 times more likely to recur than normal sinus rhythm after a 5-year course. In our study, 20% of patients suffered from chronic atrial fibrillation after ten years. Furthermore, left atrial appendage closure or amputation significantly reduces stroke in patients who undergo CABG and develop postoperative atrial fibrillation. Thus, OPCAB is a minimally invasive procedure with fewer complications; prevention of cardiogenic cerebral infarction can help improve remote outcomes.

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.

Evidence and Challenges in Left Atrial Appendage Management

This review aimed to discuss the anatomical properties of the left atrial appendage (LAA), its relationship with atrial fibrillation (AF), effectiveness of LAA occlusion (LAAO), techniques, and new devices used to perform this procedure. An electronic search was performed to identify studies, in the English language, on LAA management. Searches were performed on PubMed Central, Scopus, and Medline from the dates of database inception to February 2020. For the assessed papers, data were extracted from the reviewed text, tables, and figures, by two independent authors. Anticoagulant therapy for patients with AF has proven beneficial and is highly recommended, but it is challenging for many patients to maintain optimal treatment. Surgery is the most cost-effective option; surgical methods include simple LAA resection, thoracoscopic surgery, and catheter treatment. Each procedure has its advantages and disadvantages, and many prospective studies have been conducted to evaluate various treatment methods. In managing the LAA, dissection of the LAA, such as changes in its shape and size due to remodeling during AF, changes in autonomic nerve function, and thrombosis, must be understood anatomically and physiologically. We believe that early treatment intervention for the LAA should be considered particularly in cases of recurrent AF.

Conclusion: SLET under artificial pneumothorax is feasible and safe in minimally invasive McKeown esophagectomy.

Left atrial appendage exclusion is effective in reducing postoperative stroke after mitral valve replacement

OBJECTIVE

This study aimed to evaluate the role of surgical left atrial appendage (LAA) exclusion in the prevention of stroke after mitral valve replacement (MVR).

METHODS

We retrospectively reviewed clinical data of 860 patients who received MVR in our center from January 2008 to January 2013. The patients were randomly assigned to two surgical groups, namely LAA exclusion group (n = 521) and LAA nonexclusion group (n = 339) according to whether concurrent surgical exclusion of the LAA was to be undertaken or not before surgery in a blind fashion. MVR was performed by two experienced surgeons. The LAA was explored during the operation and mural thrombus removed in all cases. The LAA was left intact in nonocclusion group whereas the neck of the LAA was closed with a two-layer continued suture in exclusion group. The incidence of early postoperative ischemic stroke between the two groups was compared.

RESULTS

The patients' age was 53 ± 12 years, with 48.1% male and 67.9% with rheumatic disease. Mural thrombosis was seen in 18.8% of the patients and atrial fibrillation (AF) coexisted in 62.4%. All operations were successfully performed and no difference was noted in in-hospital mortality, re-exploration for bleeding, and other major complications between the two groups. The incidence of ischemic stroke in LAA exclusion group was significantly lower than in nonexclusion group (0.6% vs. 2.7%, p = .011). The subgroup multivariate analysis showed that LAA exclusion significantly reduced the risk of postoperative stroke in patients with AF (odds ratio [OR] = 0.070, 95% confidence interval [CI]: 0.006-0.705, p = .025) but not in non-AF patients (OR = 1.902, 95% CI: 0.171-21.191, p = .601).

CONCLUSIONS

Concurrent LAA exclusion during MVR is a safe and effective way to reduce postoperative ischemic stroke, particularly in patients with AF.

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.

A functional evaluation of cerebral perfusion for coronary artery bypass grafting patients

We evaluate the utility of providing a pulsatile blood flow by applying off-pump coronary artery bypass grafting (CABG) or intra-aortic balloon pumping (IABP) with conventional CABG to prevent perioperative stroke in patients with cerebral hypoperfusion on single-photon emission-computed tomography (SPECT). A total of 286 patients underwent isolated CABG with a cerebral magnetic resonance angiography (MRA) evaluation between 2006 and 2015. Seventy-five had significant stenosis and/or occlusion of craniocervical vessels; the other 211 had no significant stenosis. Cerebral SPECT was performed for 49 (SPECT group) of the 75 patients. The SPECT group was further divided into a normal perfusion (NP) (n = 37); and a hypoperfusion (HP) (n = 12). In the present study we compared the NP group and the 211 patients with no significant stenosis (as a control group) to the HP group. No strokes occurred in the HP group, and 1 stroke occurred at the time of operation in the control group. Postoperative stroke within 30 days occurred in 3 patients in the control group; the difference was not statistically significant. The long-term stroke-free rates of the HP and Control group did not differ to a statistically significant extent. The functional evaluation of cerebral perfusion by SPECT is important when patients have significant stenotic lesions on cerebral MRA. Maintaining an adequate pulsatile flow by off-pump CABG or IABP with conventional CABG will help prevent perioperative stroke, even if cerebral hypoperfusion is detected by SPECT.

Incidence of perioperative stroke in clampless aortic anastomosis during off-pump coronary artery bypass grafting

This study aimed to assess if clampless off-pump coronary artery bypass grafting (OPCAB) decreases the incidence of perioperative stroke (POS) rate and in-hospital mortality. The secondary aim was to evaluate 12-year rates of overall mortality. Between January 2003 to December 2015, data of 645 consecutive patients undergoing isolated CABG were retrospectively collected. 363 underwent aortic no-touch OPCAB (No-touch group) and 282 underwent OPCAB with the Heartstring device (HS group). In-hospital mortality and perioperative stroke rate as primary endpoint, as well as long-term follow-up outcome were analysed. In-hospital mortality was lower into No-touch group compared with HS group but without significant statistical difference (1.7 vs. 3.2%, p = 0.19, respectively); the rate of postoperative stroke was higher in No-touch group compared with HS group, although this difference did not reach statistically significance. Delirium was reported with higher presentation rate in HS group (3.9 vs. 0.8%, p = 0.01). Blood transfusions rate was higher in HS subjects (23.4 vs. 16.1%, p = 0.01). Intubation time, ICU, and hospital length of stay were increased in the HS group (p = 0.008, p = 0.001 and p = 0.003, respectively). Over a 12-year follow-up period, survival probabilities at 1, 5, and 10 years were 93.6 ± 1.3 vs. 93.2 ± 1.5, 80.4 ± 2.6 vs. 80.3 ± 2.2, and 57.9 ± 5 vs. 58.4 ± 3.8% in the No-touch and HS group, respectively (p = 0.97). In this retrospective study, clampless off-pump CABG lowers perioperative stroke rate whose incidence is, however, not inferior compared with No-touch technique, and no statistically significance was detected. Delirium has a higher presentation rate in clampless off-pump CABG.