Evaluation of the thickness of coronary calcium by 60-MHz intravascular ultrasound: head-to-head comparison with optical frequency domain imaging.

The region behind the coronary calcium could not be visualized by intravascular ultrasound (IVUS) because of acoustic shadow. However, some pathological studies have shown that IVUS delineated the vessel border behind thin coronary calcium sheets. This study aimed to reveal whether recent IVUS can visualize the region behind thin coronary calcium sheets. Using 534 cross-sectional optical frequency domain images (OFDI), including severe calcified coronary lesions, calcium sheet thickness was measured by every 1°. Accordingly, the visibility of the vessel border behind the coronary calcium sheet was evaluated using 60-MHz IVUS images, which were longitudinally linked with OFDI ones. After carefully coordinating with the axial position, the association between the IVUS-derived permeability of the coronary calcium sheet and calcium thickness was evaluated. The maximum and mean calcium thickness by OFDI was 0.88 ± 0.39 and 0.62 ± 0.30 mm, respectively. By 60-MHz IVUS, 12.1% of the coronary calcium sheets had permeable segments. Comparing between OFDI and IVUS images, 48.6% of the coronary calcium sheets with maximum thickness ≤ 0.3 mm were sometimes permeable by 60-MHz IVUS, whereas most > 0.5 mm thick calcium sheets were impermeable. In the receiver operating characteristic curve analysis, the best cutoff values for the maximum and mean thickness of permeable calcium were 0.48 and 0.31 mm, respectively. Thus, 60-MHz IVUS can occasionally visualize the region behind a thin coronary calcium sheet. When using 60-MHz IVUS, this finding may be a predictive marker of calcium sheet with a thickness of < 0.5 mm.

Clinical and electrocardiographic characteristics in patients with fulminant myocarditis.

Background: The purpose of this study was to evaluate clinical and electrocardiographic characteristics in patients with fulminant myocarditis. Methods: A total of 72 patients were divided into three groups: pericarditis (control: n = 25), acute myocarditis (n = 27), and fulminant myocarditis (n = 20). Patients' characteristics and electrocardiograms on admission were retrospectively analyzed in the three groups. Results: BNP levels in the fulminant group were significantly higher than those in the other two groups. ST elevation was observed at lead aVR in the fulminant myocarditis group, whereas ST depression was observed at lead aVR in the other groups (p = .001). The maximum degree of ST elevation among the three groups was similar. However, the number of ST-elevation leads in the fulminant myocarditis group was significantly lower than that in the other groups (p = .004). The voltage of R wave in lead V5 in the fulminant myocarditis group was significantly lower than that in the other groups (p = .005). Moreover, in the Cabrera sequence, the prevalence of ST elevation in the inferior leads, aVR, and V3-V6 in the fulminant myocarditis group was significantly or nearly significantly lower than that in the other groups. Conclusions: In fulminant myocarditis, ST-segment elevation was observed in lead aVR, and contrarily, the number and extent of ST-segment elevation and R wave voltage were smaller than those in the other groups. These results suggest that the number of myocytes with maintained action potential may be reduced following progressive myocardial damage and interstitial edema due to severe inflammation.

High-definition intravascular ultrasound versus optical frequency domain imaging for the detection of calcium modification and fracture in heavily calcified coronary lesion.

While optical frequency domain imaging (OFDI) can delineate calcium modification and fracture, the capability of high-definition intravascular ultrasound (HD-IVUS) for detecting these remains unclear. This study evaluated diagnostic accuracy of HD-IVUS for assessing calcium modification and fracture as compared to OFDI. HD-IVUS and OFDI were used during orbital or rotational atherectomy procedures conducted for 21 heavily calcified coronary lesions in 19 patients. With OFDI assessment used as the gold standard, diagnostic accuracies of HD-IVUS for calcium modification and fracture were compared every 1 mm to the matched pre-stenting images (n = 1129). Calcium modification, as assessed by OFDI, was defined as polished and concave-shaped calcium. For HD-IVUS, calcium modification was defined as the presence of reverberation with concave-shaped calcium. In both assessments, the definition of calcium fracture was defined as a slit or complete break in the calcium plate. Calcified plaque was found in 86.4% of analyzed OFDI images. Calcium modification and fracture were detected in 20.6% and 11.0% of detected calcified plaques. Sensitivity, specificity, positive and negative predictive values of HD-IVUS detection for calcium modification and fracture were 54.4%, 97.8%, 86.7%, 89.1% and 86.0%, 94.5%, 58.2%, 96.8%, respectively. Discordance cases between both assessments demonstrated that heterogeneous calcium visualized by OFDI, separated calcium, and guide wire artifact can be misdiagnosed. Diagnostic accuracies of HD-IVUS for assessing calcium modification and fracture were acceptable as compared to OFDI. Such findings can be of utility during imaging guided interventional procedures with atherectomy.