📄 medicine

Recurrent stroke following left atrial appendage closure in patients with ischemic stroke under oral anticoagulation: a systematic review and meta-analysis

This systematic review and meta-analysis of 1,091 high-risk elderly patients with prior ischemic stroke despite oral anticoagulation found that left atrial appendage closure is associated with a residual annual ischemic stroke recurrence rate of 3.1%, highlighting the need for prospective trials to optimize post-procedural antithrombotic strategies.

Original authors: Tommaso Bini, Marco Gamardella, Antanas Gasys, Roberto Galea, Laurent Roten, David Seiffge, Lorenz Räber, George CM Siontis

Published 2026-07-10

📖 4 min read☕ Coffee break read

CC BY 4.0

Original authors: Tommaso Bini, Marco Gamardella, Antanas Gasys, Roberto Galea, Laurent Roten, David Seiffge, Lorenz Räber, George CM Siontis

Original paper licensed under CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). ✨ This is an AI-generated explanation of the paper below. It is not written or endorsed by the authors. For technical accuracy, refer to the original paper. Read full disclaimer

Imagine your heart is a bustling city with a tiny, quiet alleyway called the Left Atrial Appendage. In most people, this alley is just a dead end. But for some, it's a hidden garage where blood clots (like little traffic jams) love to hide and build up. If one of these clots escapes the garage, it can zoom out and cause a stroke—a major traffic accident in the brain.

Usually, doctors give patients a special "traffic controller" medicine called oral anticoagulation (OAC) to keep the roads clear and stop these jams from forming. But sometimes, even with the best traffic controller on duty, a clot still manages to sneak out. This is called a "breakthrough stroke." It's like having a security guard who does a great job, but a sneaky thief still finds a way through the back door.

For these unlucky patients who get a stroke despite taking their medicine, doctors have a new idea: instead of just relying on the guard, why not lock the garage door shut? This procedure is called Left Atrial Appendage Closure (LAAC). It's like welding the alleyway closed so the clots have nowhere to hide.

The Big Question
A team of researchers from Switzerland decided to investigate: If we weld the garage door shut for patients who have already had a "breakthrough" stroke, how often do they get another one? They didn't just guess; they gathered data from eight different studies involving 1,091 patients to see what actually happened.

What They Found
The results showed that even with the garage door welded shut, the risk isn't zero. The researchers calculated that for these high-risk patients, the rate of having another stroke is about 3.1% per year (specifically 3.14% per year, with a range of 2.35% to 4.20%).

To put that in perspective, imagine a group of 100 people with this specific problem. If they all get the garage door welded shut, about 3 of them might still have a stroke within a year. That's better than doing nothing (which some other studies suggest could be as high as 7.2% per year for similar patients), but it's not a magic shield that guarantees safety.

The "How" Matters (And It's Confusing)
Here is where the story gets tricky. The researchers noticed that the doctors in these eight studies didn't agree on what medicine to give the patients after the surgery.

In one study, everyone got two types of blood-thinning pills (Dual Antiplatelet Therapy).
In five other studies, most people (over 70%) kept taking their original "traffic controller" medicine (OAC), sometimes with an extra pill.
In some cases, patients stopped the strong medicine entirely after a while.

Because the "after-care" was so different in every study, the researchers couldn't say for sure if the surgery alone was the hero, or if the specific mix of medicines helped too. It's like trying to figure out if a new car engine is fast, but some drivers are using premium gas, some are using regular, and some are driving with the handbrake on. You can't tell exactly what's making the car go.

What the Paper Says We Don't Know Yet
The authors are very clear about what they haven't proven. They explicitly state that we cannot yet say this is the perfect solution.

They do not claim that stopping the strong medicine (OAC) is safe. In fact, they point out that in the study where everyone kept taking the medicine, the stroke rate was very low (0%), while in the study where everyone switched to just blood-thinning pills, the rate was higher (7.59%). This suggests that locking the door plus keeping the traffic controller might be the best combo, but they haven't proved it yet.
They do not say this works for everyone. The patients in these studies were mostly elderly (average age between 71.8 and 78.1 years) and had very high risk scores (CHA₂DS₂-VASc scores of 5.0 or higher).

The Bottom Line
This study suggests that welding the garage door shut is a promising move for patients who have already failed their medicine, lowering the annual stroke risk to around 3.1%. However, because the "after-care" plans were all over the map, the researchers say we need more proof.

They are calling for new, strict experiments (randomized trials) to answer the big questions: Should we keep the medicine going forever? Is the surgery better than just the medicine? Until those new studies happen, this procedure is a powerful tool, but not a solved puzzle. The door is welded, but the traffic rules are still being written.

Technical Summary: Recurrent Stroke Following Left Atrial Appendage Closure in Patients with Ischemic Stroke Under Oral Anticoagulation

Problem Statement
Atrial fibrillation (AF) significantly increases the risk of thromboembolic events, particularly ischemic stroke. While oral anticoagulation (OAC) is the standard of care, a subset of patients (1–2% per year) experiences "breakthrough stroke" despite appropriate therapy. This population faces a high risk of recurrent ischemic stroke (5–9% in the first year), yet current guidelines do not recommend switching anticoagulants or adding antiplatelet therapy for these patients. Percutaneous left atrial appendage closure (LAAC) has emerged as a potential therapeutic add-on for these high-risk individuals, but the incidence of recurrent stroke following LAAC in patients who have already failed OAC has not been systematically evaluated.

Methodology
The authors conducted a systematic review and meta-analysis following PRISMA guidelines, registered in the Open Science Framework.

Search Strategy: A computerized search of MEDLINE, Embase, and Cochrane Central Register of Controlled Trials (CENTRAL) was performed from January 1, 2010, to December 31, 2025.
Eligibility Criteria: Studies were included if they reported the incidence of ischemic stroke recurrence after LAAC in patients with a prior thromboembolic event occurring despite OAC therapy. Case reports and case series were excluded. Overlapping populations were resolved by selecting the most recent or most comprehensive publication.
Data Extraction: Two reviewers independently extracted data on study design, population characteristics, procedural details, and post-procedural antithrombotic management (OAC alone, OAC + antiplatelet therapy, or dual antiplatelet therapy).
Statistical Analysis: The primary outcome was the annualized incidence rate of ischemic stroke recurrence. A random-effects model with the Hartung-Knapp-Sidik-Jonkman (HKSJ) adjustment was used to calculate the pooled incidence rate, accounting for anticipated heterogeneity.

Key Contributions and Results

Study Population: Eight studies comprising 1,091 patients met the inclusion criteria. The population was consistently elderly (mean age 71.8–78.1 years) and at high thromboembolic risk (mean CHA₂DS₂-VASc scores ≥ 5.0).
Antithrombotic Heterogeneity: Post-procedural management varied significantly across studies. While five studies reported >70% of patients discharged on OAC (alone or combined with antiplatelet therapy), one study discharged all patients on dual antiplatelet therapy (DAPT). Follow-up OAC usage ranged from 8.1% to 100% across studies.
Primary Outcome: At a mean follow-up of 17.7 months, the pooled annualized incidence rate of ischemic stroke recurrence following LAAC was 3.14% per year (95% CI 2.35%–4.20%).
Heterogeneity: The statistical analysis detected no significant between-study heterogeneity regarding the recurrence rate ( $I^2 = 0.0\%$ ).
Safety: Periprocedural safety events ranged from 0% to 7.8%. All-cause mortality ranged from 0% to 20%, with rates ≤7.7% in seven of the eight studies. Hemorrhagic stroke rates were low (0% and 0.3% in the two studies reporting them).

Significance and Claims
The paper claims to provide the most comprehensive synthesis of evidence to date regarding ischemic stroke recurrence after LAAC in patients with prior breakthrough stroke. The authors highlight that while the observed recurrence rate of ~3.1% per year appears numerically lower than the historical 7.2% rate reported for patients with breakthrough stroke on OAC alone, these findings must be interpreted with caution.

The authors emphasize that the substantial variability in post-procedural antithrombotic strategies (ranging from DAPT to indefinite OAC) makes it difficult to isolate the protective effect of LAAC itself from the concomitant pharmacological therapy. They note that studies where patients remained on OAC post-LAAC (e.g., Masjuan et al.) showed lower recurrence rates compared to those on DAPT (e.g., Pracon et al.).

Consequently, the paper concludes that while LAAC appears to offer a degree of stroke prevention in this high-risk group, the optimal antithrombotic strategy remains undefined. The authors assert that prospective randomized controlled trials (specifically citing the ongoing ELAPSE, ADD-LAAO, and LAAOS-4 trials) are urgently needed to definitively establish the protective impact of LAAC and determine the best antithrombotic regimen for patients with prior ischemic stroke despite OAC. The study acknowledges limitations including the lack of a control group, the observational nature of all included data, and potential selection bias due to limited neurologist adjudication of stroke events in some studies.

Technical Summary: Recurrent Stroke Following Left Atrial Appendage Closure in Patients with Ischemic Stroke Under Oral Anticoagulation

More like this