Evaluation of Prospective ECG-Triggered CT Scan as a Practical Alternative to Standard Retrospective ECG-Gated Scan...

Purpose: CT-TAVI is a critical component of pre-TAVI assessment. The conventional method, retrospective ECG-gated scan, covering a complete cardiac cycle, measures the annulus during optimal systolic phases. Recently, prospective ECG-triggered scans acquiring images at a specific interval of the cardiac cycle were evaluated, allowing faster acquisition and lower contrast doses. Moreover, these scans might be beneficial for elderly patients, reducing the need for breath-holding and easing cooperation requirements. Still, their impact on annular measurement and procedural success has yet to be fully evaluated. Methods: This retrospective, single-center study included 419 patients who underwent CT-TAVI scans, by either prospective or retrospective scanning methods. Baseline data and calculated surgical risk scores were collected, with propensity score matching performed, followed by univariate analysis, Cox regression, and multivariable regression analysis. Results: A total of 171 patient pairs were generated via propensity score matching, ensuring that both groups had similar distributions of age (81 ± 8 years), sex (55% males), and baseline comorbidities. The patients in the prospective ECG-triggered group were exposed to a smaller amount of contrast material (40.0 ± 12 mL vs. 70.0 ± 48 mL, p < 0.001) and radiation (4.4 ± 3.6 mSv vs. 8.0 ± 10.3 mSv, p < 0.001). The prospective ECG-triggered group had a smaller aortic annulus area and diameter (426.6 ± 121.0 mm² vs. 469.1 ± 130.8 mm², p = 0.006 and 23.3 ± 3.2 mm vs. 24.5 ± 3.6 mm, p = 0.004) but no excess paravalvular leak was observed. Multivariable analysis showed no significant differences in mortality and composite endpoints between the two groups after 23 months of follow-up. Conclusion: Prospective ECG-triggered, ultra-fast, low-dose, high-pitch scan protocol, used in selected patients offers comparable safety and clinical procedural outcomes along with time and contrast savings.