Development and validation of a risk score for transthyretin amyloidosis detection in patients with severe aortic stenosis
A Antonopoulos, T Tsampras, P Kanatas, M Ioannides, M Koutelou, A Naka, A Zacharoulis, G Katsimagklis, G Filippatos, I Ninios, E Vavouranakis, S Maragkoudakis, G Kochiadakis, K Tsioufis, C VlachopoulosAbstract
Background
Transthyretin cardiac amyloidosis (ATTR) is common in patients undergoing transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS), yet optimal screening strategies have not been clearly established.
Purpose
We aimed to develop and validate a risk score for predicting ATTR in patients diagnosed with severe AS undergoing TAVI.
Methods
In the prospective multicentre GRECA-TAVI registry, 500 patients with severe AS scheduled for TAVI were screened for ATTR using technetium-99m–labelled DPD or PYP bone scintigraphy across 12 tertiary hospitals in Greece and Cyprus, between January 1 and December 31, 2024. Clinical, echocardiographic, and electrocardiographic data were collected. An integer-based risk score derived from logistic regression was developed in a training cohort (n = 350) and subsequently validated in a validation cohort (n = 150). Model performance was assessed in terms of discrimination, calibration, and decision curve analysis.
Results
ATTR was diagnosed in 38 patients (7.7%). Patients with ATTR were older, more frequently male, and had lower LVEF, greater maximal wall thickness (MWT), higher prevalence of atrial fibrillation, and increased rates of intracardiac device implantation. Five variables (age, sex, MWT, LVEF, and intracardiac device presence) formed the basis of an 8-point risk score. The score demonstrated good discrimination (AUC=0.75 training, 0.76 validation). A score ≥4 identified patients with a ~16% ATTR prevalence compared to 2.4% in those with a score<4. This threshold captured the most of the ATTR cases (73%) while recommending screening for only 36% of the cohort. Decision curve analysis showed net clinical benefit across clinically relevant thresholds (5-20%) over and above a guideline-recommended approach (based on MWT≥12mm) or a screen-all strategy.
Conclusions
ATTR is frequent among patients with severe AS undergoing TAVI. A simple bedside score based on routinely available variables can effectively identify patients at increased risk for ATTR. Targeted screening using this tool may enhance diagnostic yield and optimize resource utilization.FigureFor image description, please refer to the figure legend and surrounding text.