A CT-based algorithm stratifies patients into 3 coronary obstruction risk categories during TAVR, and a novel volumetric parameter (valve-to-coronary volume) independently predicted coronary obstruction with an AUC of 0.841, outperforming VTC distance alone, though coronary protection efficacy is limited in patients with very small VTCV.
Key Findings
Results
A CT-based risk stratification algorithm classified TAVR patients into three coronary obstruction risk categories, with 58.5% at low risk, 24.4% at intermediate risk, and 17.1% at high risk.
Study enrolled 164 patients prospectively identified as at risk for coronary obstruction during TAVR.
96 of 164 patients (58.5%) were classified as low risk.
40 of 164 patients (24.4%) were classified as intermediate risk.
28 of 164 patients (17.1%) were classified as high risk.
Classification was based on preprocedural CT using a published algorithm.
Results
All seven coronary obstruction events occurred exclusively in the high-risk group.
A total of 7 CO events were observed across the entire cohort of 164 patients.
Zero CO events occurred in the low-risk or intermediate-risk groups.
All CO events (n = 7) occurred in the high-risk group.
This finding validates the algorithm's ability to identify a high-risk subgroup.
Results
Coronary protection (CP) was used at rates that varied substantially by risk category, but real-world CP decisions appeared to incorporate additional clinical and procedural variables beyond the CT algorithm.
CP was performed in 12.8% of low-risk patients (16 of 125).
CP was performed in 52.8% of intermediate-risk patients (28 of 53).
CP was performed in 93.9% of high-risk patients (31 of 33).
The decision to use CP was left to the heart team, reflecting real-world practice variability.
Results
Both VTC distance and the novel valve-to-coronary volume (VTCV) parameter were significantly lower in patients who experienced coronary obstruction.
VTC distance was significantly lower in patients with CO compared to those without (P = 0.006).
VTCV was significantly lower in patients with CO compared to those without (P = 0.005).
VTCV is a volumetric parameter calculated using sinus width and VTC distance.
VTCV was calculated specifically in high-risk cases.
Results
VTCV independently predicted coronary obstruction with an AUC of 0.841, outperforming VTC distance alone.
VTCV area under the curve (AUC) was 0.841 (95% CI: 0.702–0.979; P < 0.001).
VTCV outperformed VTC distance alone as a predictor of CO.
VTCV was identified as an independent predictor of CO.
The predictive value of VTCV was validated in an external cohort including 11 European centers.
Results
Coronary protection reduced coronary obstruction risk but had limited efficacy in patients with very small VTCV.
Despite CP being performed, CO events still occurred in some high-risk patients.
Patients with very small VTCV experienced CO even when coronary protection was used.
VTCV can be calculated preprocedurally via CT, enabling identification of this very high-risk subgroup before the procedure.
The authors conclude that CP efficacy 'is limited in patients with very small VTCV.'
Methods
The study was a prospective, registry-based study enrolling patients at risk for coronary obstruction during TAVR, with external validation across 11 European centers.
Registered under NCT05015452 (Leipzig TAVR Registry).
164 patients were enrolled prospectively.
Clinical endpoints followed Valve Academic Research Consortium 3 (VARC-3) definitions.
External cohort validation included 11 European centers.
Preprocedural CT was the primary imaging modality for risk stratification and VTCV calculation.
What This Means
This research suggests that a CT scan-based scoring system can reliably sort patients undergoing transcatheter aortic valve replacement (TAVR) — a minimally invasive heart valve procedure — into three groups based on their risk of a rare but dangerous complication called coronary obstruction, where the new valve blocks blood flow to the heart's arteries. In a prospective study of 164 high-risk patients, all seven cases of coronary obstruction occurred only in the group classified as highest risk by the CT algorithm, suggesting the tool successfully identifies who is truly at elevated risk. However, in real clinical practice, doctors' decisions about whether to take protective measures (called 'coronary protection') did not always closely follow the algorithm, suggesting that clinical teams weigh additional factors beyond what the CT algorithm captures.
A key new finding from this study is the introduction of a novel measurement called the 'valve-to-coronary volume' (VTCV), which combines information about the space between the new valve and the coronary artery openings. This volumetric measurement predicted coronary obstruction better than the previously used single-distance measurement, with a strong predictive accuracy (AUC of 0.841). Importantly, this VTCV measurement was validated across 11 European medical centers, supporting its broader applicability.
This research suggests that while protective measures during TAVR can reduce the risk of coronary obstruction, they may not be fully effective in patients whose VTCV is extremely small — and this subset of very high-risk patients can be identified before the procedure using standard CT imaging. This could help heart teams plan more tailored protective strategies or consider alternative approaches for the most vulnerable patients.
Abdelhafez A, Lankisch N, Iannopollo G, Dumpies O, Rotta Detto Loria J, Richter I, et al.. (2026). CT-Based Risk Stratification of Coronary Obstruction During TAVR: Clinical Utility and a New Volumetric Parameter.. JACC. Cardiovascular interventions. https://doi.org/10.1016/j.jcin.2026.04.015