Transapical aortic valve implantation: The Vancouver experience.
Bibliographic record
Abstract
INTRODUCTION: Off-pump transapical aortic valve implantation (TA-TAVI) through mini-thoracotomy was first performed in Vancouver, Canada in October 2005. The objective of this manuscript is to describe the Vancouver experience with 178 TA-TAVI cases in symptomatic severe aortic stenosis (AS) since 2005. METHODS: Baseline characteristics and in-hospital outcomes were calculated for the overall cohort. To compare pre-procedure and post-procedure echocardiographic measurements, one way analysis of variance was utilized, followed by Tukey's HSD. In-hospital outcomes were compared between early and late cohorts using Z-test and chi-squared test as appropriate. Kaplan-Meier analysis was used to generate 3-year survival curves. The Log-rank test was used to compare survival between low-risk and high-risk groups, based on STS score. RESULTS: Between October 2005-March 2012, TA-TAVI was performed in 178 patients. Mean age was 80.5±8.6 years. Congestive heart failure and renal failure were more common in the late cohort, while previous myocardial infarction was more common in the early cohort (P<0.05). Eleven patients (6.2%) had significant intra-operative complications, including death (1.7%), conversion to CPB (3.9%), and valve embolization (1.1%). In-hospital survival was 87.9%. Mean length of hospital stay was 12.2±17.1 days. In-hospital incidence of stroke was 3.4%. Bleeding (20.2% vs. 4.7%) and vascular (14.6% vs. 3.5%) complications were more common in the early cohort. Echocardiography demonstrated a significant increase in aortic valve area and decrease in mean transvalvular gradient post-procedure. These improvements were maintained throughout the 3-year follow-up period. Overall survival was 72.1% at 6 months, 67.7% at 12 months, 55.5% at 24 months, and 47.3% at 36 months. Repeated Kaplan-Meier analysis for the 2 groups stratified by STS score, demonstrated improved survival in the low-risk group (Log-rank P=0.039). CONCLUSIONS: Among patients with symptomatic severe AS at high risk for conventional AVR, TA-TAVI is a reasonable therapeutic option with acceptable risk. Long-term survival appears to be superior in lower-risk patients.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 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".