Abstract Background The study goal was to assess the accuracy of PCCT and EID CT for lumen area analysis against IVUS as the reference. Methods In this single-center, pilot retrospective observational study we included 42 patients who underwent coronary computed tomography angiography (CCTA) for suspected coronary artery disease demonstrating ≥1 atherosclerotic lesion in a coronary artery with a reference diameter 2. 0 mm. Patients were divided into two groups with 21 individuals scanned with PCCT and 21 scanned with EID CT (second and third generation). Eligible patients also underwent intravascular ultrasound (IVUS) within 150 days of CCTA, with pullback recordings covering the CCTA-identified lesion and at least two coronary segments without prior intervention. On average two lesions are expected from each performed IVUS what will give ~30 observations per group. Agreement between CCTA from both types of scanners and intravascular ultrasound (IVUS) derived lumen area measurements were assessed using the Bland-Altman method. The mean difference (bias) and 95% Limits of Agreement (LoA) was calculated for both distinct measurement groups. Coronary angiography, CCTA, and IVUS data were reviewed by an expert cardiologist using anatomical landmarks, particularly side branch origins, to identify segments with lumen diameter ≥2 mm on CCTA and assessed by IVUS. Exclusion criteria were poor CCTA quality (Likert score = 1), inadequate IVUS (including absence of automated pullback), or clinical events between CCTA and IVUS that could alter plaque morphology. IVUS pullbacks were analyzed with CAAS IntraVascular v2. 1 by an expert analyst and adjudicated by a blinded cardiologist; stented segments were excluded. Results Preliminary Bland-Altman analysis demonstrated a large disparity in systematic bias between PCCT group (bias = 0. 19 mm2, sd = 0. 14 mm2) and EID CT group (bias = 0. 71 mm2, sd = 0. 58 mm2), resulting in a substantial inter group difference of 0. 52 mm2. To assess the feasibility of detecting this difference, a two-sample t-test power analysis was conducted. Based on the calculated pooled standard deviation (sdₚooled ≈ 0. 42 mm2), the standardized effect size (d) was 1. 23, classified as very large. Testing the null hypothesis of no difference in bias (H0: µ1 = µ2) at an α of 0. 05, a sample size of n = 30 observations per group was calculated to achieve a statistical power of 99. 68 %. These preliminary data confirm that a sample size n = 30 of per group was highly sufficient to detect a significant difference between the two measurement biases, justifying this sample size for the full cohort study. Conclusions PCCT offers lower bias in MLA assessment than EID CT in reference to IVUS therefore may be considered as more reliable tool in coronary intervention and surgery planning. Further research will be conducted to verify whether PCCT shows superiority over EID CT in quantitative atherosclerotic plaque evaluation and procedure planning.
Kruk et al. (Sun,) studied this question.