Feasibility of left atrial strain assessment using cardiac computed tomography in patients with paroxysmal atrial fibrillation.

PURPOSE: To evaluate the feasibility of left atrial strain (LAS) assessment using cardiac computed tomography (CT) in patients with paroxysmal atrial fibrillation (PAF). METHODS: This retrospective single-center study included 98 patients with PAF who underwent cardiac CT and echocardiography before the first catheter ablation. LAS was analyzed using cardiac CT (CT-LAS) and speckle-tracking echocardiography (STE; STE-LAS). LA reservoir (LASr), conduit (LASc), and pump strain (LASp) were calculated by averaging LAS measured in 4- and 2-chamber views. The results were compared using Pearson's correlation coefficients, paired t-tests, and Bland-Altman analysis. Intraclass correlation coefficients (ICCs) were used to evaluate reproducibility. RESULTS: CT-LAS could be analyzed in all patients, while STE-LAS could be analyzed in 53 (54%) patients. LASr, LASc, and LASp showed significant correlations between CT- and STE-LAS: LASr, r = 0.68, p < 0.001; LASc, r = 0.47, p < 0.001; LASp, r = 0.67, p < 0.001. LASr, LASc, and LASp of CT- and STE-LAS were 23.7 ± 6.0% and 22.1 ± 6.7%, 11.1 ± 3.6% and 11.1 ± 4.1%, and 12.6 ± 4.6% and 11.0 ± 4.1%, respectively. LASr and LASp were significantly higher in CT-LAS than that in STE-LAS (p = 0.023 for LASr and p = 0.001 for LASp). CT-LAS showed excellent reproducibility. The intra- and interobserver ICCs were 0.96 to 0.99 and 0.89 to 0.90, respectively. CONCLUSION: CT-LAS was successfully analyzed in more patients than STE-LAS and was highly reproducible. The findings suggest that CT-LAS is feasible for patients with PAF.

The Clock-Drawing Test as a Useful Screening Assessment of Preoperative Cognitive Impairment with Readmission After Transcatheter Aortic Valve Implantation.

Background: Transcatheter aortic valve implantation (TAVI) has recently become more common as a treatment for severe, symptomatic aortic stenosis (AS). Cognitive impairment (CI) is strongly associated with the prognosis of TAVI patients. However, some cognitive assessments currently in use are difficult to perform routinely in the clinical setting. To easier CI evaluation, we investigated whether CI using the clock-drawing test (CDT), one part of the Mini-Cog, affects the postoperative prognosis of TAVI patients with AS. Methods: The present study enrolled 52 patients (median age, 85 years; 28.8% male) who underwent TAVI and were discharged between 2019 and 2021. The outcome was readmission for all causes within one year of discharge and patients were grouped according to whether they were readmitted or not. Cognitive function was assessed using the Mini-Cog which combines verbal playback and CDT. Results: Of the 52, 11 patients (21.2%) comprised readmission group, including 4 (36.4%) each for fracture and infection, and 1 (9.1%) each for heart failure, subdural hematoma, and pneumothorax. Median Mini-Cog score was lower in the readmission group than in the non-readmission group (4 vs. 5; P < 0.05). The frequency of Mini-Cog score < 3 (indicative of CI) and CDT failure were significantly higher in the readmission group than in the non-readmission group, respectively (46% vs. 7%, P < 0.01) (46% vs. 12%, P < 0.05). Both of Mini-Cog score < 3 and CDT failure were independently associated with readmission. The areas under the curve showed CDT was an indicator of readmission with similar accuracy to the Mini-Cog score < 3. Kaplan-Meier curves showed significant differences in readmission after 1 year between the 2 Mini-Cog groups with scores of < 3 or ≥ 3 points and CDT failure and success. Conclusion: The CDT may be a very easy and simple screening assessment of preoperative CI with readmission within one year after TAVI.

Left atrial strain assessment using cardiac computed tomography in patients with hypertrophic cardiomyopathy.

PURPOSE: To evaluate left atrial (LA) function in patients with hypertrophic cardiomyopathy (HCM) by LA strain assessment using cardiac computed tomography (CT-derived LA strain). MATERIALS AND METHODS: This was a retrospective study of 34 patients with HCM and 31 non-HCM patients who underwent cardiac computed tomography (CT) using retrospective electrocardiogram-gated mode. CT images were reconstructed every 5% (0-95%) of the RR intervals. CT-derived LA strain (reservoir [LASr], conduit [LASc], and booster pump strain [LASp]) were semi-automatically analyzed using a dedicated workstation. We also measured the left atrial volume index (LAVI) and left ventricular longitudinal strain (LVLS) for the left atrial and ventricular functional parameters to assess the relationship with CT-derived LA strain. RESULTS: CT-derived LA strain significantly correlated with LAVI: r = - 0.69, p < 0.001 for LASr; r = - 0.70, p < 0.001 for LASp; and r = - 0.35, p = 0.004 for LASc. CT-derived LA strain also significantly correlated with LVLS: r = - 0.62, p < 0.001 for LASr; r = - 0.67, p < 0.001 for LASc; and r = - 0.42, p = 0.013 for LASp. CT-derived LA strain in patients with HCM was significantly lower than that in non-HCM patients: LASr (20.8 ± 7.6 vs. 31.7 ± 6.1%, p < 0.001); LASc (7.9 ± 3.4 vs. 14.2 ± 5.3%, p < 0.001); and LASp (12.8 ± 5.7 vs. 17.6 ± 4.3%, p < 0.001). Additionally, CT-derived LA strain showed high reproducibility; inter-observer correlation coefficients were 0.94, 0.90, and 0.89 for LASr, LASc, and LASp, respectively. CONCLUSION: CT-derived LA strain is feasible for quantitative assessment of left atrial function in patients with HCM.

Late iodine enhancement computed tomography with image subtraction for assessment of myocardial infarction.

OBJECTIVE: To evaluate the feasibility of image subtraction in late iodine enhancement CT (LIE-CT) for assessment of myocardial infarction (MI). METHODS: A comprehensive cardiac CT protocol and late gadolinium enhancement MRI (LGE-MRI) was used to assess coronary artery disease in 27 patients. LIE-CT was performed after stress CT perfusion (CTP) and CT angiography. Subtraction LIE-CT was created by subtracting the mask volume of the left ventricle (LV) cavity from the original LIE-CT using CTP dataset. The %MI volume was quantified as the ratio of LIE to entire LV volume, and transmural extent (TME) of LIE was classified as 0%, 1-24%, 25-49%, 50-74% or 75-100%. These results were compared with LGE-MRI using the Spearman rank test, Bland-Altman method and chi-square test. RESULTS: One hundred twenty-five (29%) of 432 segments were positive on LGE-MRI. Correlation coefficients for original and subtraction LIE-CT to LGE-MRI were 0.79 and 0.85 for %MI volume. Concordances of the 5-point grading scale between original and subtraction LIE-CT with LGE-MRI were 75% and 84% for TME; concordance was significantly improved using the subtraction technique (p <0.05). CONCLUSION: Subtraction LIE-CT allowed more accurate assessment of MI extent than the original LIE-CT. KEY POINTS: • Subtraction LIE-CT allows for accurate assessment of the extent of myocardial infarction. • Subtraction LIE-CT shows a close correlation with LGE-MRI in %MI volume. • Subtraction LIE-CT has significantly higher concordance with TME assessment than original LIE-CT.