Late Lumen Gain Research Articles

Optical coherence tomography assessment of dissection following Drug-Coated Balloon treatment in de-novo small vessel disease

Abstract Background/Introduction Several studies have shown either favorable or unfavorable effects of dissection following drug-coated balloon (DCB) angioplasty. However, there is no established method to precisely assess the extent of dissection during DCB treatment and the relationship between dissection and late lumen gain (LLG) remains unclear. Purpose The aim of this study is to develop a new method to quantify the dissection and investigate the impact of dissection volume on angiographic outcomes. Methods The present study consisted of patients enrolled in the randomized TRANSFORM-I trial, comparing novel Magic TouchTM sirolimus coated-balloon with SeQuent Please NeoTM paclitaxel coated balloon (PCB) in patients with de-novo small vessel coronary artery disease. One-hundred lesions in 98 patients were investigated with OCT after pre-dilatation to assess the dissection. A customized software (QCU-CMS, Leiden) precisely quantifies the dissection and lumen volumes separated by a common boundary connecting the two edges of the intimal fracture. Quantitative OCT analysis of dissection volume is derived from cross-sectional slices with a thickness of 200 microns. Tissue composition analysis, using OCT-Deep Learning (DL) (Pulse, Shanghai), at the starting site of the dissection was performed to elucidate the mechanisms triggering the dissection. Results The dissection was found in 96% (96/100) of the treated lesions. The median dissection volume was 1.98 (0.57 – 3.89)mm3. The median maximal dissection arc was 113 degree. The tissue composition analysis showed that the dissection occurs at the thinnest site (320 μm) of fibrous intima (83%) (Figure). The 6-month angiographic outcomes of TRANSFORM-I will be presented at the late breaking session by then the mechanistic determinant of late loss and gain will have been examined in details. Conclusions Quantitative OCT analysis of dissection demonstrated that dissection occurs during DCB treatment. Final results with 6-month outcome, relationship between the dissection volume and late lumen loss (LLL) or LLG will be presented at the time of congress.Figure

Impact of Late Lumen Loss on Clinical Outcomes of Side-Branch Bifurcation Lesions Treated by Drug-Coated Balloon Angioplasty With Main-Branch Stenting

BackgroundDrug-coated balloon (DCB) angioplasty for side branches with main branch stenting is effective for bifurcation lesions and reduces late lumen loss (LLL) in side branches. However, the predictors and clinical implications of LLL after DCB angioplasty are largely unexplored. MethodsAmong 181 patients undergoing DCB angioplasty for side branches with drug-eluting stent implantation for main branches between 2016 and 2018, we enrolled 138 patients (138 lesions) undergoing follow-up coronary angiography within 1 year. The 1-year cumulative rates of target lesion revascularization (TLR) and major adverse cardiac events (MACE: defined as a composite of all-cause death, myocardial infarction, and TLR) were compared between patients with late lumen gain (LLG) (LLG group) and those with LLL (LLL group). ResultsThe binary restenosis rate of the side branch was 8.0% (11 lesions), mean LLL was −0.14 ± 0.43 mm, and LLG was observed in 99 lesions (71.7%). The DCB size/reference vessel diameter ratio showed mild discrimination (area under the curve, 0.60; 95% confidence interval, 1.2–65.0; p = 0.03) for predicting the side branch progression. The 1-year cumulative rates of MACE and TLR were not significantly different but numerically lower in the LLG group than in the LLL group (2.0% vs. 7.8%, p = 0.11 and 2.0% vs. 7.7%, p = 0.11, respectively). Lumen regression after DCB angioplasty for side branches are associated with improved clinical outcomes. Conclusions: The DCB size relative to the reference vessel diameter is a predictor of late lumen enlargement in side branches.

First in human evaluation of the vascular biocompatibility and biomechanical performance of a novel ultra high molecular weight amorphous PLLA bioresorbable scaffold in the absence of anti-proliferative drugs: Two-year imaging results in humans.

In this first-in-human study, we prospectively studied the vascular compatibility and mechanical performance of a novel bare ultra-high molecular weight amorphous PLLA bioresorbable scaffold (BRS, FORTITUDE®, Amaranth Medical, Mountain View, California) up to two years after implantation using multimodality imaging techniques. The vascular biocompatibility of polymers used in BRS has not been fully characterized in the absence of anti-proliferative drugs. A total of 10 patients undergoing single scaffold implantation were included in the final analysis and were followed up using optical coherence tomography (OCT) at 2-years. All devices were implanted under angiographic and intravascular ultrasound (IVUS) guidance. Angiographic and IVUS follow up was performed at 6 months. Additionally, angiography and OCT imaging were performed at 2-years. At 6 months, mean intra-scaffold angiographic MLD slightly decreased from baseline procedural values. However, at 2 years, mean angiographic MLD increased (post procedure; 2.9 [2.7, 3.1] mm vs. 6 months; 2.1 [1.6, 2.5] vs. 2 years; 2.4 [2.1, 2.6], P = .001). Also, angiographic percent diameter stenosis decreased and late lumen gain increased between 6 months and 2 years follow up. Mean neointimal hyperplasia volume assessed by IVUS at 6 months was 26% [15.2, 29.3]. At 2 years OCT follow up neointimal hyperplasia volume was 24.2% [19.4, 28.9]. No presence of neoatherosclerosis was identified in any of the analyzed cases. At 2 years, this novel PLLA-based BRS induced expansive vascular remodeling from 6 to 24 months, a biological phenomenon that appears to be independent of the presence of anti-proliferative drugs.

Bioresorbable Polymers and Stent Devices.

Percutaneous coronary interventions will never become obsolete, as evolution is inherent to interventional cardiology. Current drug-eluting platforms have appreciably improved their safety and efficacy profiles in different clinical settings compared to first-generation devices such that it is difficult to consider other alternatives. However, there is definite biological plausibility to consider devices with bioabsorbable polymers and/or scaffolds. It is also an undeniable fact that many patients, based on variety of belief systems, would prefer not to have a permanently implanted device. BP DES with or without bioresorbable scaffolds offer advantages over durable polymer DES in restoring normal coronary physiology and vascular adaptive responses, resulting in late lumen gain and plaque regression. They will likely allow flexibility in treating complex CAD. However, so far, we have been able to prove non-inferiority in a selected population of patients without long-term data. Is "as good as" good enough? Are we ready to reach for the BRS or a BP DES in our catheterization laboratory based on preclinical and mechanistic data (endothelialization, OCT imaging, vasomotion) with limited human experience? I am not. While I will maximize my efforts to recruit patients in related randomized controlled trials, the technology is not ready for prime time. Randomized controlled trials are needed to determine whether any or all of these devices improve long-term outcome compared to best in class DP DES. Most definitive evidence is likely about a decade away. Until then, we can learn to be disciplined implanters not only in selecting the appropriate patient but also in perfecting implantation techniques.

Procedural safety and short-term outcome in asian men treated with magnesium bio-resorbable scaffold

Background: Bioresorbable scaffold offer the advantages of reduced long-term complications such as stent fracture, late stent thrombosis and in-stent restenosis as well as the return of normal vasomotor function and late lumen gain with plaque regression. Objective: Identify safety and outcomes of patients undergoing percutaneous coronary intervention (PCI) with magnesium BRS. Materials and methods: This was a prospective, observational single centre study conducted in UiTM Sungai Buloh from 1st November 2016 to 14th February 2017. Results: 7 patients were enrolled. The mean age was 46±9. All patients were male. Ethnicity breakdown showed 5 Malays, 1 Chinese, and 1 Indian. Cardiovascular risk assessment revealed 85.7% diabetes mellitus, 42.9% smokers, 28.6% hypertension and 28.6% dyslipidaemia. Target vessels treated were 6 left anterior descending (LAD) and 1 right coronary artery (RCA). Out of the 7 patients, 28.6% were type A lesions, 42.8% were type B, and 28.5% were type C. Among those lesions, 4 involved LAD-D1 bifurcations, and 2 were total occlusions. The lesions were prepared with semi-compliant balloons in 5 cases and non-compliant balloons in 2 cases. The balloon-to-stent ratios were 1:1 (n=1), 0.92:1 (n=1), 0.85:1 (n=4) and 0.83:1 (n=1). The magnesium BRS diameters used were 3.5 mm (n=4) and 3.0 mm (n=3) with length of 15 mm (n=1), 20 mm (n=4) and 25 mm (n=2). Post-dilatation in one patient was carried out with non-compliant balloon of equal diameter to the stent, while the rest had upsizing with +0.5 mm larger non-compliant balloon. Procedural outcome was 100% successful. At three-month follow-up, there were no symptoms, MACE or TLR. Conclusion: We demonstrated safety and good short-term outcome in the use of magnesium BRS in our cohort, including stenting of total occlusions as well as bifurcation lesions. A larger cohort and longer-term outcome would better delineate the safety and efficacy of this new technology in treating coronary artery disease.

TCT-833 Late Lumen Gain with Bioresorbable Vascular Scaffold in the Porcine Model of Spontaneous Untreated Atherosclerosis: a 3-year IVUS and OCT Study

TCT-833 Late Lumen Gain with Bioresorbable Vascular Scaffold in the Porcine Model of Spontaneous Untreated Atherosclerosis: a 3-year IVUS and OCT Study

Prediction of Chronic Vessel Enlargement by a Novel Intravascular Ultrasound Finding

Coronary arterial segments distal to the severely stenotic lesion sometimes shrink as a result of decreased coronary flow. Pathological studies have shown that vessel shrinkage is accompanied by folding of the internal elastic membrane (IEM). A peri-medial high-echoic band (PHB) by intravascular ultrasound (IVUS) may represent folding of the IEM and therefore detect chronically shrunken coronary segments that have potential to enlarge subsequently. METHODS AND RESULTS: IVUS imaging of the distal reference segments was performed in 27 patients after stenting. PHB was defined as a high-echoic band observed at the luminal side of the media. Serial (baseline and 9 months) changes in minimal lumen diameter (LD) were compared between those with (PHB group) and without PHB (non-PHB group). During follow-up, LD increased significantly in PHB group (1.2±0.3 vs. 1.7±0.5 mm, P=0.001) but not in the non-PHB group (2.0±0.7 vs. 2.1±0.7 mm, P=NS). Late lumen gain (LLG) was observed in 16 of the 27 (59%) lesions. Lesions with LLG showed a trend toward smaller baseline lumen cross-sectional area and significantly higher prevalence of PHB (88% vs. 18%, P=0.007). By multivariable logistic regression analysis, PHB was the only IVUS predictor of LLG. Presence of PHB on IVUS predicts chronic enlargement of the coronary segments distal to the stented lesion.

Late Positive Remodeling and Late Lumen Gain Contribute to Vascular Restoration by a Non-Drug Eluting Bioresorbable Scaffold

The interplay between mechanical dilatation, resorption, and arterial response following implantation of bioresorbable scaffolds is still poorly understood. Long-term geometric changes in porcine coronary arteries in relation to gradual degradation of bioresorbable scaffolds were assessed in comparison with bare metal stents (BMS). Intravascular ultrasound (IVUS)-derived lumen, outer stent/scaffold, and reference vessel areas were evaluated in 94 polymer scaffolds and 46 BMS at 5 days and 3, 6, 12, 18, 24, and 55 months, in addition to polymer scaffold radial crush strength and molecular weight (M(W)) at 3, 6, and 12 months. BMS outer stent area and lumen area remained constant through 55 months (P=0.05, but within 1 standard deviation of 100%, and P=0.58, respectively), while significant increases were exhibited by polymer-scaffolded vessels with the maximum late lumen gain at 24 months, paralleled by the outer scaffold area increase, and then remaining at that increased level at 55 months (P<0.01). By 12 months polymer scaffolds experienced significant reductions in radial strength and M(W), while the animals underwent the largest weight gain. At 3 months and beyond, the patency ratio (lumen area/reference vessel area) of BMS remained constant (0.71 to 0.85, P=0.49). In contrast, that of polymer scaffolds increased and approached 1 (P=0.13). Bioresorbable polymer scaffolds allow restoration of the treated segment's ability to remodel outward to achieve level lumen transition between reference vessel and scaffold-treated regions, a process mediated by animal growth and scaffold degradation. This also introduces a challenge to standard analyses of IVUS outcomes relying on constant stent diameters over time.

TCT-447: Late Positive Remodeling as a Mechanism of Late Lumen Gain in Bioresorbable Stents: Intravascular Ultrasound Study in a Normal Porcine Coronary Model

TCT-447: Late Positive Remodeling as a Mechanism of Late Lumen Gain in Bioresorbable Stents: Intravascular Ultrasound Study in a Normal Porcine Coronary Model

Arterial remodeling after coronary angioplasty: a serial intravascular ultrasound study.

Restenosis occurs after 30% to 50% of transcatheter coronary procedures; however, the natural history and pathophysiology of restenosis are still incompletely understood. Serial (postintervention and follow-up) intravascular ultrasound imaging was used to study 212 native coronary lesions in 209 patients after percutaneous transluminal coronary angioplasty, directional coronary atherectomy, rotational atherectomy, or excimer laser angioplasty. The external elastic membrane (EEM) and lumen cross-sectional areas (CSA) were measured; plaque plus media (P+M) CSA was calculated as EEM minus lumen CSA. The anatomic slice selected for serial analysis had an axial location within the target lesion at the smallest follow-up lumen CSA. At follow-up, 73% of the decrease in lumen (from 6.6+/-2.5 to 4.0+/-3.7 mm2, P<.0001) was due to a decrease in EEM (from 20.1+/-6.4 to 18.2+/-6.4 mm2, P<.0001); 27% was due to an increase in P+M (from 13.5+/-5.5 to 14.2+/-5.4 mm2, P<.0001). Delta Lumen CSA correlated more strongly with delta EEM CSA (r=.751, P<.0001) than with delta P+M CSA (r=.284, P<.0001). Delta EEM was bidirectional; 47 lesions (22%) showed an increase in EEM. Despite a greater increase in P+M (1.5+/-2.5 versus 0.5+/-2.0 mm2, P=.0009), lesions exhibiting an increase in EEM had (1) no change in lumen (-0.1+/-3.3 versus 3.6+/-2.3 mm2, P<.0001), (2) a reduced restenosis rate (26% versus 62%, P<.0001), and (3) a 49% frequency of late lumen gain (versus 1%, P<.0001) compared with lesions with no increase in EEM. Restenosis appears to be determined primarily by the direction and magnitude of vessel wall remodeling (delta EEM). An increase in EEM is adaptive, whereas a decrease in EEM contributes to restenosis.

Late coronary artery stenosis regression within the gianturco-roubin intracoronary stent

The late angiographic outcome of the Gianturco-Roubin intracoronary stent has not been well defined. To investigate serial changes within the stent, we studied 23 patients (15 men and 8 women, median age 63) who had late angiographic follow-up (>1 year) after undergoing Gianturco-Roubin stenting for angioplasty-associated acute or threatened native coronary artery closure. Coronary angiography before and after stenting, at 6-month follow-up, and at late return was analyzed with quantitative coronary angiography. The median time from stent deployment to late angiographic follow-up was 27 months. As expected, stenting significantly increased the median minimal lumen diameter (MLD) acutely from 1.0 to 2.46 mm. Median percent diameter stenosis decreased from 66% to 18%. Although at 6 months there was a significant loss of the acute gain (median MLD decreased from 2.46 to 1.9 mm), with a corresponding increase in percent stenosis from 18% to 31%, late angiography demonstrated lesion regression, median MLD increasing from 1.9 to 2.15 mm (p = 0.004), and percent stenosis decreasing from 31% to 21% (p = 0.0026). No patient had a significant decline in minimal lesion diameter, and 5 patients had a >50% increase in MID at late follow-up. Linear regression analysis of 6-month MLD and late lumen gain suggested that lesions with the greatest regression were those with the lowest lumen diameters at 6-month angiography. Late angiographic analysis demonstrated significant lesion regression within the Gianturco-Roubin stent, which was sometimes dramatic. In suggesting that coronary arteriography at 6 months may underestimate the late angiographic benefit of intracoronary stenting, these data have important clinical implications, and imply that patients with a stable clinical course and angiographic stent restenosis may often be followed rather than routinely redilated.

935-32 Differing Mechanisms of Late Arterial Responses to Transcatheter Therapy: A Serial Quantitative Angiographic and Intravascular Ultrasound Study

To evaluate the mechanisms of late arterial response to transcatheter therapy, we analyzed serial quantitative angiographic minimum lumen diameter (MLD) and diameter stenosis (DS) and intravascular ultrasound external elastic membrane (EEM), lumen, and plaque area in 137 lesions treated with various devices (31 PTCA, 57 directional and 26 rotational atherectomy, and 23 excimer laser angioplasty). From serial angiography (post-intervention and at follow-up 4.7 ± 2.8 mos later), lesions were divided into 3 groups based on Δ MLD and follow-up %DS. From serial intravascular ultrasound, late lumen loss (Δlumen area), geometric remodeling (ΔEEM area). and tissue growth (Δplaque area) were calculated for each group: ↑MLD (N = 14) ↓MLD, but DS &lt; 0.5 (N = 44) ↓MLD and DS ≥ 05 p (N = 79) Post-intervention EEM (mm 2 ) 20.1 ± 3.7 20.7 ± 7.0 20.2 ± 6.5 NS Lumen (mm 2 ) 7.4 ± 2.0 7.0 ± 2.3 5.4 ± 2.2 &lt; 0.0001 Plaque (mm 2 ) 12.7 ± 3.7 13.7 ± 5.9 14.8 ± 5.8 NS Follow-up EEM (mm 2 ) 21.3 ± 8.0 20.0 ± 6.6 18.0 ± 5.8 0.0849 Lumen (mm 2 ) 8.7 ± 6.7 5.6 ± 30 1.8 ± 1.5 &lt; 0.0001 Plaque (mm 2 ) 12.6 ± 4.0 13.9 ± 5.0 16.2 ± 6.0 0.0169 Late lumen loss (mm 2 ) -1.3 ± 6.3 1.4 ± 2.6 3.5 ± 2.4 &lt; 0.0001 Remodeling (mm 2 ) -1.2 ± 7.6 0.7 ± 2.9 2.3 ± 2.7 0.0014 Tissue growth (mm 2 ) -0.1 ± 4.0 0.7 ± 1.5 1.3 ± 2.4 0.0831 Geometric remodeling correlated with tissue growth (r = 0.426, p &lt; 0.0001), but was independent of device used. We conclude: Patterns of the late arterial response following coronary intervention are determined less by tissue growth than by the direction and magnitude of geometric remodeling. Late lumen gain is the result of “overcompensation” with an increase in EEM area and minimal tissue growth. Late lumen loss without angiographic restenosis is the result of modest tissue growth with no decrease in EEM area. Angiographic restenosis is associated with moderate tissue growth, but is predominantly the result of geometric remodeling; a decrease in EEM area accounts for 66% of late lumen area loss