CT-derived extracellular volume ≥40.2% independently predicts composite endpoint in severe aortic stenosis, improving risk prediction beyond EuroSCORE II and PRIORiTize (HR ~4).
Does CT-derived extracellular volume provide independent and incremental prognostic information beyond established clinical risk markers in patients with severe symptomatic aortic stenosis?
CT-derived extracellular volume provides incremental prognostic value beyond standard clinical scoring systems for predicting mortality and cardiovascular hospitalization in patients with severe aortic stenosis undergoing TAVR evaluation.
Absolute Event Rate: 0% vs 0%
Abstract Background Severe aortic stenosis (AS) has a poor prognosis without timely intervention. While risk stratification is primarily guided by clinical scores, myocardial extracellular volume estimation using cardiac computed tomography (ECV-CT), a marker of fibrosis, has emerged as a promising prognostic tool. This study sought to determine if ECV-CT can provide independent and incremental prognostic information to established clinical risk markers. Methods This prospective single-center study included consecutive patients with severe symptomatic AS undergoing pre-TAVR (transcatheter aortic valve replacement) CT. Patients with prosthetic aortic valves or known cardiac amyloidosis were excluded. Imaging was performed using a 192-slice dual-source CT scanner, with ECV-CT obtained via an additional post-contrast, low-radiation-dose, prospective acquisition (Figure 1A). ECV-CT values were compared with two risk scores: EuroSCORE II and PRIORiTize-TAVI. The composite endpoint was time to all-cause mortality or cardiovascular hospitalization. Results A total of 316 patients (mean age 81 ± 8 years; 44% male; mean transaortic gradient 50 ± 15 mmHg; mean aortic valve area 0.74 ± 0.19 cm²; mean left ventricular ejection fraction 56 ± 11%) were analyzed. The median ECV-CT was 33.9% (IQR 29.5-38.7). Over a median follow-up of 340 days (IQR 198–517), the composite endpoint occurred in 72 patients (23%), including 47 deaths (15%) and 25 cardiovascular hospitalizations (8%). Patients reaching the endpoint were older (84 ± 8 vs. 80 ± 8 years, p=0.012), had lower LV ejection fraction (51 ± 13 vs. 57 ± 10%, p0.001), higher NT-proBNP levels (4002 pg/mL (IQR 929-8678) vs. 838 (IQR 377-2126), p0.001), and higher scores on both EuroSCORE II (6.32 ± 5.12 vs. 4.05 ± 3.23%, p=0.002) and PRIORiTize (4.4 ± 1.6 vs. 3.3 ± 1.3, p=0.008). These patients also had higher median ECV-CT values (39.8% (IQR 33.5-44.2) vs. 32.9% (IQR 29.5-38.3), p=0.001). Decision tree analysis identified an ECV-CT value ≥40.2% as the best threshold for predicting outcomes (Figure 1B). Patients with ECV-CT ≥40.2% (n=53) accounted for 17% of the study population but were responsible for 29% of all events. Multivariate Cox regression showed that logECV-CT remained an independent predictor of the composite endpoint after adjusting for EuroSCORE II (HR 4.2, 95%CI 1.3-13.9, p=0.016) and PRIORiTize (HR 3.9, 95% CI 1.3-11.6, p=0.012). Finally, nested regression models of the global Chi-square value of the likelihood ratio test demonstrated that incorporating logECV-CT significantly improved the predictive performance of both EuroSCORE II and PRIORiTize (Figure 1C). Conclusion CT-derived ECV provides incremental prognostic value beyond clinical scoring systems in patients with severe AS, aiding in identifying higher-risk patients. The potential role of this marker for clinical decision-making warrants further investigation.
Carvalho et al. (Sat,) reported a other. CT-derived extracellular volume ≥40.2% independently predicts composite endpoint in severe aortic stenosis, improving risk prediction beyond EuroSCORE II and PRIORiTize (HR ~4).