Photon-counting CT accurately screens TAVR patients for signs of valve dysfunction
Photon-counting CT (PCCT) may be an effective way to evaluate patients for signs of prosthetic valve dysfunction following transcatheter aortic valve replacement (TAVR), according to new data published in the Journal of Cardiovascular Computed Tomography.[1]
The study’s authors noted that both transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) can be used to image these patients, but each modality is associated with certain issues that make them less than ideal.
Cardiac CT, meanwhile, is starting to be used more and more as technologies continue to evolve. Whether it would be a good fit for this exact purpose remains unclear.
“Although cardiac CT provides time-resolved data that would theoretically enable additional functional assessment, prior investigations have been limited to native aortic valves and have relied on specifically fitted regression models,” wrote Sardi Hyska, MD, a researcher with Medical University of South Carolina, and colleagues. “These results cannot be readily applied to external cohorts or generalized to TAVR prostheses due to additional imaging challenges, such as calcifications and the TAVR stent frame.”
To learn more, Hyska et al. reviewed data from 63 patients who underwent post-TAVR PCCT examinations. The median age of 77 years old, and 59% of patients were women. All exams were performed on a first-generation PCCT system from Siemens Healthineers. The median time between TAVR and cardiac CT was 109 days.
TTE was also performed on each patient, typically on the same day, and those results served as the reference standard for this study.
Overall, the group found that hemodynamic parameters derived from time-resolved cardiac CT images strongly correlated with TTE-based parameters. The PCCT findings were able to accurately detect potential valve dysfunction, delivering an area under the ROC curve of 0.94, sensitivity of 88.9%, specificity of 88.6%, accuracy of 88.7% and Youden index-derived optimal cutoff of 20.4 mmHg. The positive predictive value was 88.9% and negative predictive value was 88.6%.
“These findings suggest that PCCT can simultaneously provide high-quality anatomical visualization and physiologically grounded hemodynamic information in post-TAVR patients, thereby extending its diagnostic role into the realm of functional prosthetic valve imaging,” the authors wrote.
Click here to read more in the Journal of Cardiovascular Computed Tomography, a Society of Cardiovascular Computed Tomography journal.
Michael has more than 19 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.