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Background The long-term prognostic impact of IVUS findings following Absorb BVS implantation remains uncertain. This study aimed to identify the IVUS predictors of long-term clinical outcomes following ABSORB bioresorbable vascular scaffold (BVS) implantation from the pooled IVUS substudy cohorts of the ABSORB III and Japan trials. Methods A total of 298 lesions in 286 patients were enrolled with 2:1 randomization to ABSORB BVS vs. cobalt-chromium everolimus-eluting stents. This sub-analysis included 168 lesions of 160 patients in the Absorb arm whose post-procedural quantitative IVUS were available. The primary endpoint of this analysis was device-oriented composite endpoint (DOCE) of target lesion failure, including cardiac death, target vessel-related myocardial infarction, or ischemia-driven target lesion revascularization. The median follow-up duration was 4.9 [3.1–5.0] years. Results During follow-up, DOCE occurred in 10.1% of lesions treated with Absorb BVS. Among several post-procedural IVUS indices associated with DOCE, non-uniform device expansion (defined as uniformity index = minimum / maximum device area) (hazard ratio 0.47 per 0.1 increase [95%CI 0.28 to 0.77]; p = 0.003) and residual reference plaque burden (hazard ratio 4.01 per 10% increase [95%CI 1.50 to 10.77]; p = 0.006) were identified as independent predictors of DOCE by Cox multivariable analysis. Conclusions Nonuniform device expansion and substantial untreated residual plaque in reference segments were associated with long-term adverse events following BVS implantation. Baseline imaging to identify the appropriate device landing zone and procedural imaging to achieve uniform device expansion if possible (e.g. through post-dilatation) may improve clinical outcomes of BVS implantation. Clinical trial registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT01751906 (ABSORB III); NCT01844284 (ABSORB Japan).

Background: Despite optimal medical therapy, a myocardial bridge (MB) can cause life-limiting symptoms in a subset of patients. While surgical unroofing has been shown to improve MB-derived refractory angina, diagnostic indices of clinical symptoms and predictors of improvement following surgery are yet to be elucidated. Methods: To identify determinants of preoperative symptoms and their improvement following the surgery, preoperative intravascular ultrasound (IVUS) and coronary computed tomography angiography were evaluated in 111 patients with symptomatic MB who underwent surgical unroofing. The primary outcome was the Seattle Angina Questionnaire summary score (the average of physical limitation, angina frequency, and quality of life scores). In addition to standard anatomic variables of an MB, degrees of extrinsic vessel restriction at end-diastole and end-systole were evaluated by IVUS using the ratio of measured vessel area and interpolated reference at the maximum compression site. The diastolic restriction was also evaluated by coronary computed tomography angiography as the maximum lumen area stenosis within the MB segment. Results: Even during diastole, IVUS revealed vessel restriction in 87% of the patients. Among the variables evaluated, vessel restriction was the strongest parameter correlating with the preoperative Seattle Angina Questionnaire summary score, particularly when assessed in diastole ( P P =0.006 in coronary computed tomography angiography). The diastolic restriction by IVUS also showed a weak, but significant correlation with improvement in Seattle Angina Questionnaire summary score 6 months after surgery ( P =0.004). Conclusions: Restricted arterial relaxation in diastole, rather than the degree of systolic compression or extent of an MB, seems to be the primary determinant of clinical symptoms and improvement in quality of life following surgical unroofing.

Introduction: Myocardial bridging (MB) has been shown to cause significant clinical symptoms or adverse cardiac events in patients with no obstructive coronary artery disease. In contrast to medical therapy or stent placement with controversial efficacy, surgical unroofing (supra-arterial myotomy) of MB is considered to directly address the pathology with durable normalization of the altered hemodynamics. In this context, preoperative IVUS assessment can provide a precise map of the MB to guide the unroofing procedure, but it remains unclear if any IVUS parameter is related to the efficacy of this treatment. Methods: We evaluated 94 consecutive patients who underwent MB unroofing with serial (preoperative and 6-month follow-up) angina assessments using the Seattle Angina Questionnaire (SAQ). The primary outcome was the SAQ summary score, obtained by averaging the scores of physical limitation, angina frequency, and quality of life. Preoperative IVUS determined total MB length, halo thickness, arterial compression rate, maximal plaque burden upstream of MB, and septal branches originating in the tunneled LAD segment. Results: In all cases, preoperative IVUS successfully offered a geographic MB map with quantitative characteristics: MB length = 27.5 (20.2 to 40.3) mm, halo thickness = 0.54 (0.41 to 0.75) mm, arterial compression rate = 34 (26 to 43)%, and plaque burden = 34 (20 to 46)% [median (range) for all]. MB unroofing resulted in significant symptomatic improvements across all scales of SAQ (p Conclusions: IVUS-guided surgical unroofing safely and effectively achieved significant symptomatic improvements in patients with MB, regardless of the morphologic or morphometric MB characteristics assessed by preoperative IVUS.

Background: IVUS-derived FFR (IVUS-FFR) is a novel technique to estimate functional severity of coronary stenosis. Using a fluid dynamics algorithm, pressure loss (ΔP) across a stenosis is calculated as ΔP = FV + SV 2 , where V is the flow velocity; F and S are the coefficients defined based on IVUS-determined minimum lumen area (MLA), stenosis length, and reference lumen area (RLA). While the first 2 variables are well defined by IVUS, the RLA can be affected by the presence of side branches near the target lesion due to blood flow distribution. Methods: To determine the threshold of side branch size that affects the RLA for IVUS-FFR calculation, 73 coronary lesions (41 LAD: 9 LCx: 23 RCA) underwent both IVUS and wire-derived FFR (W-FFR). RLA was defined as the largest lumen area proximal or distal to the target lesion with no intervening major side branches. In determining the reference site, 3 different definitions of the “major” side branch were used: >25%, >50%, and >75% of the main vessel in diameter. The diagnostic accuracy of calculated IVUS-FFR was then evaluated with each definition as referenced to W-FFR. Results: In this patient population, 42% of the lesions were physiologically significant (W-FFR 2 and 0.81±0.1, respectively. Overall, IVUS-FFR showed significant linear correlations with W-FFR (p50% definition showed the highest diagnostic accuracy (area under the curve [AUC]: 0.95) for physiologic ischemia (Figure). Conclusion: In defining the reference site for IVUS-FFR calculation, the optimal definition of the major side branch was >50% of main vessel in diameter. The current results help to develop objective and automated estimation of FFR using IVUS. Further investigation is warranted to evaluate clinical utility of combined anatomical and physiological information that IVUS may offer through this technology.

Objectives The aim of this study was to characterize post-procedural intravascular ultrasound (IVUS) findings in the ABSORB Japan trial, specifically stratified by the size of target coronary arteries. Background Despite overall noninferiority confirmed in recent randomized trials comparing bioresorbable vascular scaffolds (BVS) (Absorb BVS) and cobalt-chromium everolimus-eluting metallic stents (CoCr-EES), higher event rates of Absorb BVS have been reported with suboptimal deployment, especially in small coronary arteries. Methods In the ABSORB Japan trial, 150 patients (2:1 randomization) were scheduled in the IVUS cohort. Small vessel was defined as mean reference lumen diameter Results Overall, IVUS revealed that the Absorb BVS arm had smaller device expansion than the CoCr-EES arm did, which was particularly prominent in small- and tapered-vessel lesions. Higher tapering index was also associated with higher rates of incomplete strut apposition in Absorb BVS, but not in CoCr-EES. With respect to procedural techniques, small-vessel lesions were treated more frequently with noncompliant balloons at post-dilatation but using significantly lower pressure in the Absorb BVS arm. In contrast, tapered-vessel lesions were post-dilated at equivalent pressure but with significantly smaller balloon catheters in the Absorb BVS arm, compared with the CoCr-EES arm. Conclusions The significantly smaller device expansion especially in small vessels may account for the poorer outcomes of Absorb BVS in this lesion type. Appropriate optimization strategy, possibly different between polymeric and metallic devices, needs to be established for bioresorbable scaffold technology. (AVJ-301 Clinical Trial: A Clinical Evaluation of AVJ-301 Absorb™ BVS) in Japanese Population [ABSORB JAPAN]; NCT01844284)

intravascular ultrasound (IVUS)-derived fractional flow reserve (FFR) is a novel technique to estimate functional severity of coronary stenosis using a fluid dynamics algorithm. The pressure loss (ΔP) across a stenosis can be calculated by the following simplified equation: ΔP = FV + SV2, where

The pivotal ABSORB III and Japan trials randomized patients with noncomplex coronary artery disease to Absorb bioresorbable vascular scaffolds (BVS) versus cobalt-chromium Xience everolimus-eluting stents (EES) (both Abbott Vascular, Santa Clara, California). Formal intravascular ultrasound (IVUS)

Background The presence of a myocardial bridge ( MB ) has been shown to promote atherosclerotic plaque formation proximal to the MB , presumably because of hemodynamic disturbances provoked by retrograde blood flow toward this segment in cardiac systole. We aimed to determine the anatomic and functional properties of an MB related to the extent of atherosclerosis assessed by intravascular ultrasound. Methods and Results We enrolled 100 patients with angina but no significant obstructive coronary artery disease who had an intravascular ultrasound–detected MB in the left anterior descending artery (median age 54 years, 36% male). The MB was identified with intravascular ultrasound by the presence of an echolucent band (halo). Anatomically, the MB length was 22±13 mm, and halo thickness was 0.7±0.6 mm. Functionally, systolic arterial compression was 23±12%. The maximum plaque burden up to 20 mm proximal to the MB entrance was significantly greater than the maximum plaque burden within the MB segment. Among the intravascular ultrasound–defined MB properties, arterial compression was the sole MB parameter that demonstrated a significant positive correlation with maximum plaque burden up to 20 mm proximal to the MB entrance ( r =0.254, P =0.011 overall; r =0.545, P MB entrance. Conclusions In patients with an MB in the left anterior descending artery, the percentage of arterial compression is related directly to the burden of atherosclerotic plaque located proximally to the MB , particularly in patients who otherwise have low coronary risk. This may prove helpful in identifying high‐risk MB patients.

In second-generation bioresorbable scaffolds, thinner struts are often adopted to improve both deliverability and safety profiles, while theoretical concerns remain regarding radial strength and fracture resistance. This analysis aimed to evaluate acute and mid-term performance of the RENUVIA

Proliferation of the vasa vasorum, or periarterial small vessels (PSV), and development of attenuated-signal plaque (ASP) on IVUS have both been reported to be indicative of arterial inflammation. This study aimed to investigate potential incremental values of PSV and ASP assessment in risk

Attenuated-signal plaque (ASP) on IVUS has been shown to be indicative of plaque instability (inflammatory plaque). This study aimed to investigate possible association between underlying ASP and long-term arterial responseto bioresorbable scaffolds (BRS) vs. everolimus-eluting stents (EES). In the

Scaffold under-expansion is associated with late adverse outcomes after polymeric scaffold (BVS) implantation, while underlying mechanism of this association remains unknown. The IVUS cohort of ABSORB JAPAN trial was designed to characterize detailed device performance and long-term vessel response