Atrial Pouch
Left Atrial Diverticula Detected on Cardiac CT in Patients With Acute Ischemic Stroke: A Substudy of Mind the Heart
Year of Publication: 2025
Authors: Shan Sui Nio, Leon A. Rinkel, Olivia N. Cramer, et al.
Journal: Stroke
Citation: Stroke. 2025;56:00-00.
Link: https://www.ahajournals.org/doi/10.1161/STROKEAHA.125.051199
PDF: https://www.ahajournals.org/doi/epub/10....EAHA.125.051199
PDF: Clinical Question
Do left atrial diverticula detected on cardiac CT in patients with acute ischemic stroke predict an increased risk of recurrent ischemic stroke at 2 years?
Bottom Line
LA diverticula were found in 28% of AIS patients on cardiac CT and were associated with a 2-fold increase in recurrent ischemic stroke at 2 years (15% vs 8%; adjusted HR 2.01; 95% CI 1.08-3.77; P=0.03). Risk increased with larger diverticulum volume (adjusted HR 1.02 per 10 mm³; P=0.001). Paradoxically, patients with diverticula had better functional outcomes (median mRS 2 vs 3), likely from residual confounding.
Major Points
- LA diverticula prevalence: 126/447 (28%) of AIS patients on cardiac CT.
- Doubled recurrent stroke risk: 15% vs 8% at 2 years (adjusted HR 2.01; 95% CI 1.08-3.77; P=0.03).
- Volume-dependent risk: each 10 mm³ increase → adjusted HR 1.02 (95% CI 1.01-1.03; P=0.001). Median volume 169 mm³ in recurrence vs 101 mm³ without.
- Paradoxical better functional outcome: median mRS 2 vs 3 (adjusted cOR 0.62; 95% CI 0.42-0.92; P=0.02) — likely residual confounding.
- No thrombi detected within diverticula (0/126), though microthrombi or prior embolization plausible.
- New AF not different: 20% with diverticula vs 13% without (P=0.10).
- Morphology: 83% right superior location, 82% cystic, 83% smooth surface. Median length 6mm, width 5mm, volume 113 mm³.
- Anticoagulation imbalance: 10% vs 21% at baseline (P=0.007) — key confounder adjusted for.
- Recurrent strokes largely cryptogenic/cardioembolic: 44% cardioembolic + 44% unknown in diverticula group.
- Single-center observational (Amsterdam UMC); hypothesis-generating only.
Design
Study Type: Post hoc analysis of prospective observational cohort (Mind the Heart)
Randomization:
Blinding: None (observational)
Enrollment Period: 2018-2020
Follow-up Duration: 2 years
Centers: 1
Countries: Netherlands
Sample Size: 447
Analysis: Cox regression (recurrent stroke), ordinal logistic regression (functional outcome). STROBE reporting.
Inclusion Criteria
- Adult patients with acute ischemic stroke.
- Potentially eligible for reperfusion therapy.
- Underwent ECG-gated cardiac CT during acute stroke imaging protocol.
- Adequate cardiac CT image quality.
- Written informed consent.
Exclusion Criteria
- TIA.
- Stroke mimic.
- No cardiac CT performed.
- Insufficient cardiac CT image quality (n=5).
Baseline Characteristics
| Characteristic | LA Diverticulum (N=126) | No Diverticulum (N=321) |
|---|---|---|
| Age median (IQR) | 70 (58-79) | 73 (63-81) |
| Male sex | 80 (64%) | 184 (57%) |
| Atrial fibrillation | 14 (11%) | 62 (19%) |
| Hypertension | 52 (41%) | 154 (48%) |
| Diabetes | 21 (17%) | 50 (16%) |
| Previous stroke | 27 (21%) | 55 (17%) |
| Anticoagulation at baseline | 12 (10%) | 67 (21%) |
| NIHSS median (IQR) | 5 (2-14) | 5 (3-14) |
| Large vessel occlusion | 49 (39%) | 131 (41%) |
| IV thrombolysis | 60 (48%) | 121 (38%) |
| EVT | 32 (25%) | 69 (22%) |
| TOAST Cardioembolic | 35 (28%) | 108 (34%) |
| TOAST Cryptogenic | 46 (37%) | 114 (36%) |
Arms
| Field | LA Diverticulum Present | Control |
|---|---|---|
| Intervention | Observational group — 126 patients with LA diverticula on cardiac CT | Observational group — 321 patients without LA diverticula |
| Duration | 2-year follow-up | 2-year follow-up |
Outcomes
| Outcome | Type | Control | Intervention | HR / OR / RR | P-value |
|---|---|---|---|---|---|
| Recurrent ischemic stroke at 2 years | Primary | 24/314 (8%) | 18/124 (15%) | 2.01 | 0.03 |
| mRS at 2 years (median, IQR) | Secondary | 3 (1-6) | 2 (1-3) | Adjusted cOR 0.62 | 0.02 |
| Diverticulum volume per 10 mm³ → recurrent stroke | Secondary | — | — | Adjusted HR 1.02 | 0.001 |
| New AF during admission/follow-up | Secondary | 42/321 (13%) | 25/126 (20%) | 0.10 | |
| Observational imaging substudy | Adverse | Observational substudy of left atrial diverticula on cardiac CT - no AE data |
Subgroup Analysis
Post hoc interaction analysis: no significant interaction between anticoagulation use at baseline and LA diverticula on recurrent stroke risk.
Criticisms
- No universally accepted definition of LA diverticula — pragmatic definition (length/ostium >0.5, length ≥3mm) may not be reproducible.
- Single-center, small sample, low events — hypothesis-generating only.
- Volume underestimation: cylinder formula used (median 113 mm³) vs voxel-wise segmentation (mean 415 mm³ in prior studies).
- Residual confounding for functional outcome — diverticula group had less anticoagulation, hypertension, malignancy.
- No thrombi detected within diverticula — mechanism of embolism unproven.
- Observational design — no causal inference possible.
- 2-year follow-up only.
Funding
Dutch Heart Foundation (Dekker Junior Clinical Scientist Grant to Dr. Rinkel).
Based on: Atrial Pouch (Stroke, 2025)
Authors: Shan Sui Nio, Leon A. Rinkel, Olivia N. Cramer, et al.
Citation: Stroke. 2025;56:00-00.
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