Nahoko Kato

Fractional Flow Reserve Estimated at Coronary CT Angiography in Intermediate Lesions: Comparison of Diagnostic Accuracy of Different Methods to Determine Coronary Flow Distribution

Purpose To compare the diagnostic accuracy of different computed tomographic (CT) fractional flow reserve (FFR) algorithms for vessels with intermediate stenosis. Materials and Methods This cross-sectional HIPAA-compliant and human research committee-approved study applied a four-step CT FFR algorithm in 61 patients (mean age, 69 years ± 10; age range, 29-89 years) with a lesion of intermediate-diameter stenosis (25%-69%) at CT angiography who underwent FFR measurement within 90 days. The per-lesion diagnostic performance of CT FFR was tested for three different approaches to estimate blood flow distribution for CT FFR calculation. The first two, the Murray law and the Huo-Kassab rule, used coronary anatomy; the third used contrast material opacification gradients. CT FFR algorithms and CT angiography percentage diameter stenosis (DS) measurements were compared by using the area under the receiver operating characteristic curve (AUC) to detect FFRs of 0.8 or lower. Results Twenty-five lesions (41%) had FFRs of 0.8 or lower. The AUC of CT FFR determination by using contrast material gradients (AUC = 0.953) was significantly higher than that of the Huo-Kassab (AUC = 0.882, P = .043) and Murray law models (AUC = 0.871, P = .033). All three AUCs were higher than that for 50% or greater DS at CT angiography (AUC = 0.596, P < .001). Correlation of CT FFR with FFR was highest for gradients (Spearman ρ = 0.80), followed by the Huo-Kassab rule (ρ = 0.68) and Murray law (ρ = 0.67) models. All CT FFR algorithms had small biases, ranging from -0.015 (Murray) to -0.049 (Huo-Kassab). Limits of agreement were narrowest for gradients (-0.182, 0.147), followed by the Huo-Kassab rule (-0.246, 0.149) and the Murray law (-0.285, 0.256) models. Conclusion Clinicians can perform CT FFR by using a four-step approach on site to accurately detect hemodynamically significant intermediate-stenosis lesions. Estimating blood flow distribution by using coronary contrast opacification variations may improve CT FFR accuracy.

Relative atherosclerotic plaque volume by CT coronary angiography trumps conventional stenosis assessment for identifying flow-limiting lesions

The new methods for diagnosing the ischemia with coronary computed tomographic angiography (CTA) as a noninvasive test have been investigated. To compare the relative plaque volume to quantitative CTA and quantitative coronary angiography (QCA) for detecting flow-limiting coronary artery stenoses. We studied 49 patients with 55 intermediate lesions (30–69% diameter stenosis) who underwent CTA, coronary angiography (CAG), and FFR. CTA and QCA measures included lesion length, percent diameter stenosis (%DS), minimal lumen diameter (MLD), target main vessel percent plaque volume (%PV), lesion %PV, target main vessel percent lumen volume (%LV), and lesion %LV. FFR ≤0.80 was considered diagnostic of a flow-limiting lesion. The area under the receiver-operating characteristic curve (AUC) was used to determine the accuracy of detecting flow-limiting lesions. We also investigated the AUC of discrimination of flow-limiting lesion according to calcium score. Eighteen of 55 lesions (32.7%) had an FFR ≤0.80. Only vessel %PV differentiated between lesions with and without flow obstruction (67.6 vs. 62.7%, p = 0.018). The AUC for vessel %PV was greatest (0.76; 95% CI 0.61–0.87). The AUC for the discrimination of the flow-limiting lesions according to low calcium score (≤400) improved to 0.82 (95% CI 0.57–0.94). In intermediate coronary artery stenoses, vessel %PV is more accurate than conventional stenosis assessment for detecting flow-limiting lesions. In low calcium score, vessel %PV is more useful for diagnosis of ischemic heart disease compared with conventional quantitative measures.

Association of Dyslipidemia and Sex With Coronary Artery Calcium Assessed by Coronary Computed Tomography Angiography

Previous studies reporting that statin increases coronary artery calcium (CAC) were conducted exclusively on patients with statin as a prevention, regardless of the presence or absence of dyslipidemia. The impact of sex on CAC has not been fully evaluated. We aimed to determine the association of dyslipidemia and sex with CAC using 320-row multi-detector computed tomography (MDCT).Of the 356 consecutive patients who underwent coronary MDCT, 251 patients were enrolled, after excluding those with prior stenting and/or coronary bypass grafting or images showing motion artifacts. The primary outcome measures were the percent calcium volume (PCV) and percent atheroma volume (PAV) per coronary vessel.Multivariable analyses indicated that PCV was significantly higher in dyslipidemia patients without statins than in the subjects without dyslipidemia [partial regression coefficient (PRC): 2.59, 95% confidence interval (CI): 0.83 to 4.34, P = 0.004]. In contrast, PCV was similar in dyslipidemia patients taking statins and those without dyslipidemia (PRC: -1.09, 95% CI: -2.82 to 0.65, P = 0.22). There was no significant difference in PCV between men and women, although women exhibited a significantly lower PAV (PRC: -2.87, 95% CI: -4.54 to -1.20, P = 0.001).In low-risk patients, these results could be translated into hypotheses, which should be tested in future prospective studies. Furthermore, there was no significant difference in CAC between men and women, but women had lower PAV than men.

SIGNIFICANCE OF 6-MINUTE WALK STRESS ECHOCARDIOGRAPHY FOR PATIENTS WITH AORTIC STENOSIS

There is a paucity of an investigation of 6-minite walk stress echocardiography (6WSE) for patients with aortic stenosis (AS). The aim of this study is to investigate the significance and safety of 6WSE for AS patients. We prospectively evaluate consecutive 102 ambulant patients with moderate or

Superiority of novel automated assessment of aortic annulus by intraoperative three-dimensional transesophageal echocardiography in patients with severe aortic stenosis: Comparison with conventional cross-sectional assessment

BACKGROUND Previous studies have demonstrated that three-dimensional (3D) transesophageal echocardiography (TEE) is an alternative to multi-detector computed tomography (MDCT) for aortic valve sizing in transcatheter aortic valve replacement (TAVR). However, conventional cross-sectional analysis of aortic annulus by 3D TEE has some limitations such as lengthy analytical time. A novel software for automated valve measurement has been developed for 3D TEE. We evaluated the accuracy and analytical time of aortic annular measurements using this novel automated software in the clinical setting. METHODS We retrospectively studied 43 patients with symptomatic severe aortic stenosis (AS) who underwent TAVR. All patients underwent intraoperative TEE and MDCT. We measured aortic annular area by automated, semi-automated, and cross-sectional methods using 3D TEE datasets. These measurements were compared to the corresponding MDCT reference values. We also compared the analytical time of the three methods. RESULTS Automated and semi-automated analyses required significantly shorter analytical time compared to cross-sectional analysis (automated: 30.1±5.79s, semi-automated: 74.1±15.0s, manual: 81.8±18.5s, p<0.05). Compared to MDCT measurement (393.7±81.0mm2), annular areas measured by automated and cross-sectional methods were significantly smaller (automated: 380.6±77.1mm2, cross-sectional: 374.7±76.8mm2, p<0.05), while that obtained by semi-automated method was not significantly different (387.7±75.8mm2). Annular areas determined by semi-automated and cross-sectional analyses had narrower limits of agreement (LOA) with MDCT measurements, compared to automated analysis (automated: -68.6 to 94.7mm2, semi-automated: -48.3 to 60.2mm2, cross-sectional: -40.0 to 77.9mm2). Measurements by all three methods using 3D TEE showed high correlation with MDCT measurement (automated: r=0.86, semi-automated: r=0.94, cross-sectional: r=0.93). CONCLUSIONS For aortic annular measurements using 3D TEE in AS patients, semi-automated analysis using the novel automated software reduced analytical time while maintaining similar accuracy compared to the conventional cross-sectional analysis. This automated software may have acceptable feasibility in the clinical setting.

Accuracy and usefulness of aortic annular measurement using real-time three-dimensional transesophageal echocardiography: Comparison with direct surgical sizing

BACKGROUND There is a paucity of data that demonstrates a clinical impact of anatomical measurements of the aortic annulus by three-dimensional (3D) transesophageal echocardiography (TEE) on surgical aortic valve replacement (AVR). The aim of this study is to validate the accuracy of 3D TEE measurements compared with the direct intraoperative annular diameter and to investigate an impact of 3D TEE on a prediction of AVR with aortic annular enlargement (AAE). METHODS AND RESULTS We retrospectively enrolled 61 patients who underwent both two-dimension (2D) and 3D TEE and transthoracic echocardiography (TTE) before AVR. The annular diameters were measured noninvasively with 2D TEE (D2D) and TTE (DTTE) in a classical manner and the area- and perimeter-derived annular diameters (Darea, Dperim) were measured from using 3D TEE analysis. Intraoperative annular diameter was measured with the manufactures sizer (Dintraope). Darea showed the best agreement with Dintraope in the Bland-Altman analysis. Darea, Dperim, D2D, and DTTE correlated well with Dintraope (r=0.821, 0.820, 0.532, and 0.610, respectively; all p<0.001). Three patients underwent AVR with AAE and the specificity of Dperim for prediction of AAE was significantly higher than D2D (p=0.008). CONCLUSIONS 3D TEE measurement of aortic annular diameter showed better agreement with the direct intraoperative measurement than 2D TEE and TTE measurements. 3D TEE measurement could predict AVR with AAE more accurately than 2D TEE and TTE measurements.

IMPACT OF LESION CORONARY CALCIUM SCORE ON OUTCOMES FOLLOWING EVEROLIMUS-ELUTING STENT IMPLANTATION

Previous studies have reported that calcified lesions have worse outcomes following percutaneous coronary intervention, but the evaluation of coronary calcium was often qualitative and not quantitative. Computed tomography enabled us to quantitatively analyze coronary calcium. We sought to elucidate

CORONARY LUMINAL ATTENUATION VALUE OF CORONARY COMPUTED TOMOGRAPHY ANGIOGRAPHY IDENTIFY CORONARY ARTERY SEVERE STENOSIS: COMPARISON BETWEEN CORONARY CTA AND SPECT

Coronary luminal attenuation value of coronary CT angiography (CTA), such as coronary opacification (CO), may relate to the stenosis. We investigated the relationship of the stenosis on coronary angiography (CAG) with CO on CTA and SPECT. We retrospectively 34 patients with investigated 43 lesions

TRANSLUMINAL ATTENUATION GRADIENT PROVIDE INCREMENTAL VALUE OVER CORONARY CT ANGIOGRAPHY ALONE IN THE PREDICTION OF FLOW-LIMITING LESION AS DETERMINED BY FRACTIONAL FLOW RESERVE

This study evaluated the diagnostic performance of quantitative 320 detector-row coronary computed tomography angriography (CCTA) and transluminal attenuation gradient (TAG) for detecting flow-limiting coronary artery stenoses. We studied 49 patients with 55 intermediate lesions (30%-69% diameter

ABDOMINAL AORTIC ANEURYSM IN PATIENTS WITH ACUTE MYOCARDIAL INFARCTION: ITS PREVALENCE AND RISK FACTORS IN PROSPECTIVE STUDY

The prevalence of abdominal aortic aneurysm (AAA) is reported to be high in patients with coronary artery disease (CAD). However, it has not been fully investigated in patients with acute myocardial infarction (AMI). The aim of this study is to evaluate the prevalence of AAA and its risk factors in