Direct Implantation of Transcatheter Valve in Mitral Annular Calcification: A Multicenter Study
Bibliographic record
Abstract
BACKGROUND: Mitral valve replacement in the setting of severe annular calcification (MAC) is associated with high morbidity and mortality. Direct surgical implantation of a transcatheter heart valve (THV) through a transatrial approach is a strategy to mitigate surgical risk. This study reports the perioperative and 1-year outcomes of mitral valve replacement using a THV in patients with severe circumferential MAC at 3 Canadian centers. METHODS: Charts were reviewed between January 1, 2018 and September 30, 2023 to identify patients with severe circumferential MAC who had undergone direct implantation of a THV. Primary outcomes were 30-day mortality, debilitating stroke, and 1-year mortality. Secondary outcomes included left ventricular outflow tract obstruction, degree of paravalvular leak (PVL), transvalvular mean pressure gradient, and length of stay. RESULTS: Twenty-two patients at the 3 centers underwent direct implantation of a THV. Nineteen patients were female, with mean age of 70.41 ± 9.33 years. A THV was successfully implanted in all patients. There were 2 deaths at 30 days. Four patients died of noncardiac causes at 1 year, and 1 patient had a postoperative stroke. Seventeen (77%) patients had no PVL or trace PVL, 4 had mild PVL, and 1 patient had mild-moderate PVL. The mean transvalvular gradient was 4.42 ± 4.40 mm Hg. There were no cases of left ventricular outflow tract obstruction. CONCLUSIONS: Direct deployment of a THV in patients with severe MAC may be a reasonable option. Thirty-day and 1-year mortality rates of 9% and 18%, respectively, suggest that this approach should be reserved for high-risk patients who are not able to undergo conventional strategies.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.003 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.002 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".