Risk Assessment of Side Branch Compromise After Coronary Bifurcation Stenting　- A Substudy of the 3D-OCT Bifurcation Registry.

BACKGROUND: Side branch (SB) occlusion during bifurcation stenting is a serious complication. This study aimed to predict SB compromise (SBC) using optical coherence tomography (OCT).Methods and Results: Among the 168 patients who enrolled in the 3D-OCT Bifurcation Registry, 111 bifurcation lesions were analyzed to develop an OCT risk score for predicting SBC. SBC was defined as worsening of angiographic SB ostial stenosis (≥90%) immediately after stenting. On the basis of OCT before stenting, geometric parameters (SB diameter [SBd], length from proximal branching point to carina tip [BP-CT length], and distance of the polygon of confluence [dPOC]) and 3-dimensional bifurcation types (parallel or perpendicular) were evaluated. SBC occurred in 36 (32%) lesions. The parallel-type bifurcation was significantly more frequent in lesions with SBC. The receiver operating characteristic curve indicated SBd ≤1.77 mm (area under the curve [AUC]=0.73, sensitivity 64%, specificity 75%), BP-CT length ≤1.8 mm (AUC=0.83, sensitivity 86%, specificity 68%), and dPOC ≤3.96 mm (AUC=0.68, sensitivity 63%, specificity 69%) as the best cut-off values for predicting SBC. To create the OCT risk score, we assigned 1 point to each of these factors. As the score increased, the frequency of SBC increased significantly (Score 0, 0%; Score 1, 8.7%; Score 2, 28%; Score 3, 58%; Score 4, 85%; P<0.0001). CONCLUSIONS: Prediction of SBC using OCT is feasible with high probability.

Feasibility, reproducibility and characteristics of coronary bifurcation type assessment by three-dimensional optical coherence tomography.

AIM: To investigate the characteristics of coronary artery bifurcation type (parallel or perpendicular type) using three-dimensional (3D) optical coherence tomography (OCT), and determine the feasibility, reproducibility, assessment time and correlation with bifurcation angles measured by 3D quantitative coronary angiography (QCA). METHODS AND RESULTS: We evaluated 60 lesions at the coronary bifurcation that were treated by main vessel (MV) stenting with kissing balloon inflation (KBI) under OCT/optical frequency domain imaging (OFDI) guidance. Inter- and intra-observer agreement regarding the assessment of 3D bifurcation types were 0.88 and 0.94, respectively. The assessment times of 3D-OCT bifurcation type with OCT and OFDI were within about 30 seconds. 3D-OCT bifurcation types showed the greatest correlation with the distal bifurcation angle assessed by 3D-QCA among the three bifurcation angles (distal bifurcation angle, proximal bifurcation angle and main vessel angle), and the optimal cut-off distal bifurcation angle to predict a perpendicular type bifurcation, as determined by ROC analysis, was 51.0° (AUC 0.773, sensitivity 0.80, specificity 0.67). Based on this cut-off value for the distal bifurcation angle (51°), the diagnostic accuracy for perpendicular type bifurcation in cases with a BA ≥ 51° (n = 34) was 70.6% (24/34) and that of the parallel type bifurcation in cases of BA < 51° (n = 26) was 76.9% (20/26). CONCLUSION: Performing 3D-OCT for assessment of coronary artery bifurcation type is feasible and simple, and can be done in a short time with high reproducibility.

Inter-Technique Consistency and Prognostic Value of Intra-Procedural Angiographic and Echocardiographic Assessment of Aortic Regurgitation After Transcatheter Aortic Valve Implantation.

BACKGROUND: We investigated the relationship between intraprocedural angiographic and echocardiographic AR severity after TAVI, and the clinical robustness of angiographic assessment. Methods and Results: In 74 consecutive patients, the echocardiographic circumferential extent (CE) of the paravalvular regurgitant jet was retrospectively measured and graded based on the VARC-2 cut-points; and angiographic post-TAVI AR was retrospectively quantified using contrast videodensitometry (VD) software that calculates the ratio of the contrast time-density integral in the LV outflow tract to that in the ascending aorta (LVOT-AR). Seventy-four echocardiograms immediately after TAVI were analyzable, while 51 aortograms were analyzable for VD. These 51 echocardiograms and VD were evaluated. Median LVOT-AR across the echocardiographic AR grades was as follows: none-trace, 0.07 (IQR, 0.05-0.11); mild, 0.12 (IQR, 0.09-0.15); and moderate, 0.17 (IQR, 0.15-0.22; P<0.05 for none-trace vs. mild, and mild vs. moderate). LVOT-AR strongly correlated with %CE (r=0.72, P<0.0001). At 1 year, the rate of the composite end-point of all-cause death or HF re-hospitalization was significantly higher in >mild AR patients compared with no-mild AR on intra-procedural echocardiography (41.5% vs. 12.4%, P=0.03) as well as in patients with LVOT-AR >0.17 compared with LVOT-AR ≤0.17 (59.5% vs. 16.6%, P=0.03). CONCLUSIONS: VD (LVOT-AR) has good intra-procedural inter-technique consistency and clinical robustness. Greater than mild post-TAVI AR, but not mild post-TAVI AR, is associated with late mortality.

In vitro assessment of six aspiration catheters using a distal protection filter.

BACKGROUND: We assessed performance of 6 aspiration catheters for distal embolization using a distal protection filter in an in vitro experiment. In acute myocardial infarction, a distal protection filter is used for lesions likely to induce a distal embolism. Which aspiration cathether is most effective when used with a distal protection filter remains still unclear. METHODS: A 0.5-cm3 bolus of gelatin as a model of stagnant pools of coronary plaque debris was captured in the distal protection filter and aspirated by 6 aspiration catheters. We measured and compared the length of the suspended embolus matter. RESULTS: Among the 6 catheters evaluated, the use of the Export Advance catheter (Medtronic) resulted in significantly shorter lengths of the suspended embolus matter compared to the use of the TVAC II (Nipro), Thrombuster III SL (Kaneka), and Rebirth Pro (Goodman) catheters (p < 0.01). The residual embolus matter in all cases had drained distally to the distal protection filter when the filter was retrieved. CONCLUSIONS: The use of the Export Advance catheter showed better performance using a distal protection filter in this in vitro experiment, and its use might be more effective in preventing distal embolisms in combination with a distal protection filter.

Serial three-dimensional optical coherence tomography assessment of strut coverage and intraluminal structures after drug-eluting stent implantation.

Understanding of intraluminal structure and distribution of uncovered struts after drug-eluting stent implantation are limited by only 2-dimensional (2D) optical coherence tomography (OCT) images. We compared tissue coverage with 3-dimensional (3D) OCT and 2D quantitative analyses, and changes in intraluminal structure immediately after (baseline) everolimus-eluting stent (EES) implantation and at follow-up. The 2D analyses of uncovered struts ratio and tissue coverage thickness at a 0.5-mm interval were compared to 3D-OCT images and visually classified for the degree of tissue coverage. The difference in tissue coverage at baseline and follow-up after EES implantation was evaluated with tissue coverage scores (TCS) calculated by the 3D-OCT classification (Grade 0-3). 3D-OCT classifications were negatively correlated with uncovered-to-total struts (r = -0.864, P < 0.001) and positively correlated with tissue coverage thickness (r = 0.905, P < 0.001). Follow-up TCS was greater than baseline TCS (0.2 ± 0.4 vs. 1.4 ± 0.5, P < 0.001). Moreover, changes in intraluminal structures and longitudinal distribution of uncovered struts were assessed. Incomplete stent appositions, in-stent dissections, and thrombi were decreased at follow-up, indicating progressive arterial healing. The distribution of uncovered-to-total struts could be assessed by 3D-OCT, which was related to 2D analysis. Significant correlations between 3D-OCT classifications and quantitative analyses were shown. The classification and visual assessment of intraluminal structures by 3D-OCT were useful in evaluating arterial healing after EES implantation.

Kinetics of left ventricular rotation during exercise and its relation to exercise tolerance in atrial fibrillation: assessment by two-dimensional speckle tracking echocardiography.

BACKGROUND: Left ventricular (LV) rotation plays an important role in cardiac function both at rest and during exercise in sinus rhythm. The kinetics of rotation during exercise and the relation between exercise tolerance and rotation-related parameters in patients with atrial fibrillation (AF) are unknown. METHODS: Twenty-nine patients (age 62 ± 13 years, 6 females) with AF and preserved LV ejection fraction (LVEF) were studied using two-dimensional speckle tracking echocardiography at rest and during exercise with a supine bicycle ergometer (20 W, 10 min). We measured the systolic rotation (Rot) and the peak rotation rate in systole and early diastole (eRotR) at the apical and basal levels of the LV. All patients underwent cardiopulmonary exercise testing to obtain their percent achieved of the predicted peak oxygen consumption (% peak VO2) value. RESULTS: During exercise, apical Rot-related indices were significantly increased only in the preserved % peak VO2 group. In contrast, E/e' was significantly elevated only in the reduced % peak VO2 group. Multivariable stepwise regression analysis showed that apical ΔRot was independently associated with % peak VO2 (ß = 0.72; p < 0.01). Apical ΔeRotR, which could not be selected as an independent predictor of % peak VO2, had a good linear correlation with apical ΔRot (r = 0.81, p < 0.01). CONCLUSIONS: The augmentation of apical rotation in response to exercise may coincide with an increase of the apical derotation rate, and apical rotation reserve may reflect exercise tolerance in patients with AF and preserved LVEF.

Assessment of the aortic valve annular geometry by real-time three-dimensional transthoracic echocardiography: comparison with two-dimensional transthoracic echocardiography and multidetector computed tomography.

BACKGROUND: Real-time three-dimensional transthoracic echocardiography (3DTTE) has been developed and provides detailed 3D information, noninvasively. However, the accuracy and usefulness of 3DTTE in the evaluation of aortic root geometry are still not clear. METHODS: 2DTTE and 3DTTE were performed in 161 patients with various cardiac diseases. Multidetector computed tomography (MDCT) was performed in 35 of the 161 patients. The diameters and areas of the aortic annulus were evaluated by these three methods and compared. To evaluate the shape of the aortic annuli, eccentricity index (EI) (1 - minimum diameter/long-axis diameter) were calculated. RESULTS: Maximum dimensions of the aortic annulus measured by MDCT were significantly larger than those by 3DTTE and 2DTTE. The aortic annular areas measured by MDCT and 3DTTE were significantly larger than areas by 2DTTE. A good correlation (r = 0.85) was observed between the areas obtained by 3DTTE and MDCT; however, the correlation between the values by 2DTTE and MDCT was rough (r = 0.44). EI values in 46 % of the patients were greater than 0.1, i.e., the aortic annulus was elliptical. CONCLUSION: The images obtained by 3DTTE provided accurate values of the aortic annular area, which were equal to the values measured by MDCT. 3DTTE is a useful method to evaluate the aortic annular geometry.