Study on Heart Block Risks Using Outcome-Based Modeling (SAVIOR)
Study on Atrioventricular and Bundle Branch Block Vulnerability Identified by Outcome-based Risk Modeling （the SAVIOR Study）
Study Overview
Status
Conditions
Detailed Description
In recent years, transcatheter aortic valve replacement (TAVR) has emerged as a minimally invasive surgical approach and has gradually become a standard treatment option for patients with moderate to severe aortic stenosis（AS), particularly those at high surgical risk or deemed ineligible for conventional surgery. TAVR has been widely adopted in clinical practice.
However, post-TAVR cardiac conduction disturbances are among the most frequently observed complications, particularly complete left bundle branch block (CLBBB) and high-degree atrioventricular block (AVB) requiring permanent pacemaker implantation (PPI). These complications are associated with an increased risk of heart failure and cardiac mortality. Identified risk factors include patient-specific characteristics, electrocardiographic features, intraoperative procedural techniques, and the type of device used.
Current research on post-TAVR conduction disorders predominantly focuses on Western populations. However, Chinese AS patients exhibit distinct clinical features-such as higher degrees of valve calcification and a higher prevalence of bicuspid aortic valves-which may lead to differences in risk factors for conduction abnormalities. Moreover, prior studies have largely focused on isolated risk factors rather than developing integrated models to quantify the risk of such complications. Against this backdrop, the purpose of this study is to address the knowledge gap in postoperative risk prediction for Chinese patients. By constructing a risk prediction model tailored to Chinese AS patients for post-TAVR cardiac conduction block, we aim to improve preoperative risk assessment and individualized clinical management, thereby providing actionable guidance for clinical decision-making.
This study included 112 aortic stenosis patients undergoing TAVR at Sun Yat-sen Memorial Hospital (2017-2024), divided into internal (2017-2022) and external (2023-2024) validation cohorts.
Data covered demographics, medical history, ECG, echocardiography, biomarkers, and valve parameters. Outcomes were permanent pacemaker implantation (PPI) ≤48h post-TAVR and complete left bundle branch block (CLBBB).
Univariate logistic regression (p<0.20 threshold) and stepwise multivariate analysis (R "MASS" package, AIC-based) identified predictors for nomogram development. Model performance was assessed via AUC, C-index, ROC, and Hosmer-Lemeshow test. Internal validation used 1000 bootstrap resamples; external validation employed temporal validation. Analyses were performed in R 4.2.3 (significance: p<0.05).
Study Type
Enrollment (Actual)
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
- Child
- Adult
- Older Adult
Accepts Healthy Volunteers
Sampling Method
Study Population
This single-center retrospective study enrolled 112 consecutive patients with aortic stenosis (AS) who underwent TAVR at the Department of Cardiology, Sun Yat-sen Memorial Hospital between January 2017 and December 2024. The cohort was divided into:
Internal validation cohort: Patients treated from 2017 to 2022 (n=68)
External validation cohort: Patients treated from 2023 to 2024 (n=44)
Description
Inclusion Criteria:
- Adult patients (≥18 years old) with severe symptomatic aortic stenosis (AS) meeting 2021 ESC/EACTS Guidelines and Chinese Expert Consensus criteria (AVA <1.0 cm², or peak jet velocity ≥4.0 m/s, or mean gradient ≥40 mmHg)
- Scheduled to undergo transcatheter aortic valve replacement (TAVR) in Sun Yat-Sen Memorial Hospital
Exclusion Criteria:
- Pre-existing complete left bundle branch block (CLBBB) on baseline ECG
- Patients with pre-existing permanent pacemaker implantation
- Inability to comply with follow-up protocol
Study Plan
How is the study designed?
Design Details
Cohorts and Interventions
Group / Cohort |
Intervention / Treatment |
|---|---|
|
Permanent pacemaker implantation after TAVR surgery
|
The population undergoing TAVR for aortic valve stenosis with outcomes of permanent pacemaker implantation and complete left bundle branch block after surgery
|
|
Complete left bundle branch block occurred after TAVR surgery
|
The population undergoing TAVR for aortic valve stenosis with outcomes of permanent pacemaker implantation and complete left bundle branch block after surgery
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Measure Description |
Time Frame |
|---|---|---|
|
Permanent Pacemaker Implantation Rate for High-Grade AVB (≥Mobitz II/3°) Post-TAVR (12-Lead ECG Confirmed)
Time Frame: 7 years
|
Number of participants requiring permanent pacemaker implantation (PPI) due to high-grade atrioventricular block (AVB; ≥2nd degree Mobitz II or 3rd degree) within 48 hours post-TAVR, as clinically indicated and confirmed by 12-lead ECG and cardiology consultation
|
7 years
|
|
Complete left bundle branch block rate post-TAVR (12-lead ECG confirmed)
Time Frame: 7 years
|
Number of participants developing new complete left bundle branch block , as defined by standard ECG criteria (QRS duration ≥120ms with characteristic morphology), within 48 hours post-transcatheter aortic valve replacement.
|
7 years
|
Collaborators and Investigators
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Keywords
Additional Relevant MeSH Terms
Other Study ID Numbers
- AS-TAVR-2023-04-10
Plan for Individual participant data (IPD)
Plan to Share Individual Participant Data (IPD)?
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
product manufactured in and exported from the U.S.
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