Feasibility study of percutaneous transvalvular endomyocardial cryoablation for the treatment of hypertrophic obstructive cardiomyopathy.
Bibliographic record
Abstract
BACKGROUND: Left ventricular outflow tract (LVOT) obstruction in the setting of hypertrophic cardiomyopathy (HCM) confers negative adverse outcomes. Current nonpharmacologic treatment options include surgical myectomy and percutaneous transcoronary ablation of septal hypertrophy (TASH). While TASH negates a more invasive procedure, concern remains with particular regard to the arrhythmogenic potential of the resultant myocardial scar. Percutaneous transvalvular endomyocardial septal cryoablation (PTESC) may circumvent some of these potential limitations and offer a novel treatment strategy. OBJECTIVES: The purpose of this study was to report our early experience and outcomes with percutaneous endomyocardial cryoablation of the interventricular septum in obstructive HCM. METHODS AND RESULTS: Between March 2005 and May 2006, 3 patients (2 male, 1 female) with symptomatic obstructive HCM underwent PTESC. Basal LVOT gradients measured during left heart catheterization were 70, 126 and 100 mmHg for Patients 1, 2 and 3, respectively. Using 7 Fr and 9 Fr 8 mm tip CryoCath Freezor catheters (CryoCath Technologies, Inc., Montreal, Quebec, Canada), cryothermal energy was applied to the interventricular septum under fluoroscopic guidance. A total of 20 to 32 applications of cryothermal energy were delivered, with the mean nadir temperature sustained during cryoablation being -88 degrees Celcius. Two of the 3 patients had an immediate reduction in the LVOT gradient. However, at 6 months, only 1 patient had a significant sustained reduction in LVOT gradient. No adverse events relating to the procedure were experienced. CONCLUSION: PTESC is feasible, but did not result in a significant, sustained reduction in LVOT gradient in 2 of the 3 patients in this small series of obstructive HCM patients. The technique warrants further study to improve the consistency and duration of reduction in outflow gradient.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
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".