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.

Effect of proximal optimization technique on coronary bifurcation stent failure: Insights from the multicenter randomized PROPOT trial.

OBJECTIVE: We investigated the effect of proximal optimization technique (POT) on coronary bifurcation stent failure (BSF) in cross-over stenting by comparing with the kissing balloon technique (KBT) in a multicenter randomized PROPOT trial. BACKGROUND: POT is recommended due to increased certainty for optimal stent expansion and side branch (SB) wiring. METHODS: We randomized 120 patients treated with crossover stenting into the POT group, which was followed by SB dilation (SBD), and the KBT group. Finally, 52 and 57 patients were analyzed by optical coherence tomography before SBD and at the final procedure, respectively. Composite BSF was defined as a maximal malapposition distance of >400 µm, or malapposed and SB-jailed strut rates of >5.95% and >21.4%, respectively. RESULTS: Composite BSF before SBD in the POT and KBT groups was observed in 29% and 26% of patients, respectively. In the POT group, differences in stent volumetric index between the proximal and distal bifurcation (odds ratio [OR] 60.35, 95% confidential interval [CI] 0.13-0.93, p = 0.036) and between the proximal bifurcation and bifurcation core (OR: 3.68, 95% CI: 1.01-13.40, p = 0.048) were identified as independent risk factors. Composite BSF at final in 27% and 32%, and unplanned additional procedures in 38% and 25% were observed, respectively. Composite BSF before SBD was a risk factor for the former (OR: 6.33, 95% CI: 1.10-36.50, p = 0.039) and the latter (OR: 6.43, 95% CI: 1.25-33.10, p = 0.026) in the POT group. CONCLUSION: POT did not result in a favorable trend in BSF. Insufficient expansion of the bifurcation core after POT was associated with BSF.

Effect of proximal balloon edge dilation technique for opening a side branch ostium in repetitive-proximal optimizing technique sequence.

OBJECTIVE: The purpose of this experimental bench test was to compare stent deformation, obstruction of stent struts at a jailed side branch (SB) ostium, and stent strut malapposition between SB inflation using proximal balloon edge dilation (PBED) technique and SB inflation using conventional balloon dilation in repetitive-proximal optimizing technique (re-POT) sequence. BACKGROUND: The second proximal optimizing technique (POT) procedure in the re-POT sequence might increase obstruction of stent struts at a jailed SB ostium, because deformation of stent cells at the main branch (MB) occurred during SB inflation for opening the SB ostium. METHODS: A fractal coronary bifurcation bench model made of flexible urethane was used, and crossover single-stent implantation (Xience Sierra, Abbott Vascular, Santa Clara, CA, n = 12) was performed from the MB with the re-POT sequence. During the re-POT sequence, the jailing rate at the SB ostium assessed by videoscopy was compared between SB inflation using PBED technique (PBED group, n = 6) and SB inflation using conventional balloon dilation (conventional group, n = 6). RESULTS: The jailing rate after the second POT procedure tended to be lower in the PBED group than in the conventional group (26 ± 12% vs. 34 ± 8%, p = .211), and the change in the jailing rate during the second POT procedure was significantly smaller in the PBED group than in the conventional group (4.8 ± 5.3% vs. 11.6 ± 3.5%, p = .026). CONCLUSIONS: In the re-POT sequence, the PBED technique with a short balloon for SB inflation might minimize worsening of the jailing rate at the SB ostium during the second POT procedure.

Impact of Coronary Stent Design in Proximal Balloon Edge Dilation Technique for Bifurcation Percutaneous Coronary Intervention.

The proximal optimizing technique (POT) -proximal balloon edge dilation (PBED) sequence for side branch (SB) dilatation with cross-over single-stent implantation decreases both strut obstruction at the SB ostium and stent deformation at the main branch (MB).The purpose of this experimental bench test was to assess the impact of stent design on stent deformation, obstruction by stent struts at a jailed SB ostium, and stent strut malapposition in the POT-PBED sequence.Fractal coronary bifurcation bench models (60- and 80-degree angles) were used, and crossover single-stent implantation (3-link stent: XIENCE Sierra, Abbott Vascular, Santa Clara, CA, n = 10; 2-link stent: Synergy, Boston Scientific, Marlborough, MA, n = 10) was performed from the MB using the POT-PBED sequence. Jailing rates at the SB ostium, stent deformation, and stent strut malapposition of the bifurcation segment were assessed using videoscopy and optical coherence tomography.After SB dilatation using the PBED technique, jailing rates at the SB ostium and stent deformation did not differ significantly between the two types of stents. Conversely, the rate of malapposed struts of the bifurcation segment after the PBED procedure was significantly lower with 3-link stents than with 2-link stents for both 60- and 80-degree angles (60-degree angle: 4.3% ± 4.4% versus 22.0% ± 11.1%, P = 0.044; 80-degree angle: 20.8% ± 15.1% versus 57.2% ± 17.0%, P < 0.001, respectively).In the POT-PBED sequence, 3-link stents might be a preferable coronary bifurcation stent, maintaining a jailed SB ostium while significantly reducing stent strut malapposition of the bifurcation segment when compared with 2-link stents.

European Bifurcation Club white paper on stenting techniques for patients with bifurcated coronary artery lesions.

BACKGROUND: Defining the optimal conduction of percutaneous-coronary-intervention (PCI) to treat bifurcation lesions has been the subject of many clinical studies showing that the applied stenting technique may influence clinical outcome. Accordingly, bifurcation stenting classifications and technical sequences should be standardized to allow proper reporting and comparison. METHODS: The European Bifurcation Club (EBC) is a multidisciplinary group dedicated to optimize the treatment of bifurcations and previously created a classification of bifurcation stenting techniques that is based on the first stent implantation site. Since some techniques have been abandoned, others have been refined and dedicated devices became available, EBC promoted an international task force aimed at updating the classification of bifurcation stenting techniques as well as at highlighting the best practices for most popular techniques. Original descriptive images obtained by drawings, bench tests and micro-computed-tomographic reconstructions have been created in order to serve as tutorials in both procedure reporting and clinical practice. RESULTS: An updated Main-Across-Distal-Side (MADS)-2, classification of bifurcation stenting techniques has been realized and is reported in the present article allowing standardized procedure reporting in both clinical practice and scientific studies. The EBC-promoted task force deeply discussed, agreed on and described (using original drawings and bench tests) the optimal steps for the following major bifurcation stenting techniques: (a) 1-stent techniques ("provisional" and "inverted provisional") and (b) 2-stent techniques ("T/TAP," "culotte," and "DK-crush"). CONCLUSIONS: The present EBC-promoted paper is intended to facilitate technique selection, reporting and performance for PCI on bifurcated lesions during daily clinical practice.

Prasugrel effectively reduces the platelet reactivity units in patients with genetically metabolic dysfunction of cytochrome P450 2C19 who are treated with long-term dual antiplatelet therapy after undergoing drug-eluting stent implantation.

Dual antiplatelet therapy (DAPT) with aspirin and P2Y12 inhibitor is administered following percutaneous coronary intervention (PCI) with coronary stent implantation. Several studies have reported the effects of switching between P2Y12 inhibitors on platelet reactivity (P2Y12 reaction units: PRU), from acute to late phase after PCI. However, the effect of switching at very late phase is unknown. This study examined the effect on PRU in Japanese coronary heart disease patients with long-term DAPT (aspirin + clopidogrel) when switching from clopidogrel to prasugrel. Ninety-six patients were enrolled in this study. The median DAPT duration at enrollment was 1824.0 days. Twenty-three patients with PRU ≥ 208 at enrollment were randomly assigned into either continuing to receive clopidogrel (Continued Group; n = 11) or switching to prasugrel (Switched Group; n = 12). The primary endpoint was the rate of patients who achieved PRU < 208 at the end of 12 weeks of treatment, which was significantly higher in Switched Group relative to Continued Group (90.0% vs. 36.4%; P = 0.024). The secondary endpoint was the PRU at week 12 in groups subdivided according to cytochrome P450 (CYP) 2C19 genotypes. At week 12, extensive metabolizers (EM Group) had 202.3 ± 60.0 and 174.5 ± 22.3 in Continued Group and Switched Group (P = 0.591), respectively; intermediate and poor metabolizers (non-EM Group) had 229.4 ± 36.9 and 148.4 ± 48.4 in Continued Group and Switched Group (P = 0.002), respectively. The PRU for non-EM Group was significantly reduced in Switched Group. Thus, for patients with long-term DAPT (aspirin + clopidogrel) after PCI with coronary stent implantation, switching from clopidogrel to prasugrel resulted in a stable reduction in PRU, regardless of CYP2C19 polymorphism.

Mechanism of Residual Lumen Stenosis at the Side Branch Ostium After Final Kissing Balloon Inflation: A Volumetric Intracoronary Ultrasound Study of Coronary Bifurcation Lesions.

OBJECTIVES: To investigate the mechanisms of residual stenosis (RS) at side branch ostium (SBO) after final kissing balloon inflation (FKI) and clarify the impact of carina- and plaque-shifts on RS. BACKGROUND: Carina- and plaque-shift induce SBO compromise. FKI is an effective technique to treat this complication; however, RS often persist, and are associated with restenosis at SBO. METHODS: We performed serial volumetric analysis of 91 bifurcations in which crossover-stenting with FKI and pre-/post-intravascular ultrasounds (IVUS) were completed in both branches. The plaque- and carina-shifts were defined as an increase in the plaque-volume and a decrease in the vessel-volume at the SBO, respectively. RS at the SBO, defined as area stenosis >50% on IVUS, was identified in 19 lesions. RESULTS: After FKI, the plaque volume- significantly increased at the SBO, with its reduction in the proximal main vessel (MV). However, at the SBO, the volumetric lumen change correlated with vessel change (ρ = 0.690, P < 0.001), but not plaque change (P = 0.390), suggesting that RS at SBO was more likely associated with inadequate vessel stretch, not plaque increase after FKI. Carina-shift was more frequently found in cases with RS, compared to those without RS (37% vs. 11%, P = 0.013). Pre-procedure IVUS findings to predict RS at SBO after FKI were negative-remodeling at distal MV, plaque -burden at distal MV, and plaque-burden at the SBO. CONCLUSIONS: Carina-shift has a greater contribution to the formation of RS at SBO after FKI. The pre-procedure IVUS provides helpful information for predicting the RS after FKI.

Impact of Diabetes Mellitus on Intravascular Ultrasound-Guided Provisional Stenting in Coronary Bifurcation Lesions J-REVERSE Sub-Study.

OBJECTIVE: To investigate the impact of diabetes mellitus (DM) on provisional coronary bifurcation stenting under the complete guidance of intravascular-ultrasound (IVUS). BACKGROUND: The efficacy of such intervention has not yet been fully elucidated in the DM patients. METHODS: A total of 100 DM and 139 non-DM patients in a prospective multi-center registry of IVUS-guided bifurcation stenting were compared in angiographic results at 9 months. Vessel and luminal changes during the intervention were analyzed using the IVUS. Vascular healing at the follow-up was also investigated in 23 lesions in each group using optical coherence tomography (OCT). RESULTS: No difference was detected regarding baseline reference vessel diameter and minimum lumen diameter in proximal main vessel (MV), distal MV, and side branch (SB). The rate of everolimus-eluting stent use (78.4% vs. 78.3%), final kissing inflation (60.1% vs. 49.0%), and conversion to 2-stent strategy (2.9% vs. 2.8%) were also similar. In the DM group, late loss was greater in proximal MV (DM 0.23 ± 0.29 vs. non-DM 0.16 ± 0.24 mm, P < 0.05) and SB (0.04 ± 0.49 vs. -0.08 ± 0.35 mm, P < 0.05). Smaller vessel area restricted stent expansion in the proximal MV (6.18 ± 1.67 vs. 6.72 ± 2.07 mm2 , P < 0.05). More inhomogeneous neointimal coverage (unevenness score, 1.90 ± 0.33 vs. 1.72 ± 0.29, P < 0.05) and more frequent thrombus attachment (26% vs. 4%, P < 0.05) were documented in the proximal MV at 9-month follow-up OCT. CONCLUSIONS: Despite IVUS optimization for coronary bifurcation, DM is potentially associated with smaller luminal gain, higher late-loss, and inhomogeneous vascular healing with frequent thrombus attachment in the proximal MV.

Coronary intervention in chronic total occlusion in left main coronary artery.

An 83-year-old man who had undergone coronary aorta bypass graft surgery 25 years ago required treatment for new-onset worsening angina.

Impact of stent strut link location in proximal balloon edge dilation technique for bifurcation percutaneous coronary intervention.

The single-stent strategy has generally been accepted as the default approach to bifurcation percutaneous coronary intervention. We have proposed the proximal balloon edge dilation (PBED) technique to prevent stent deformation during side branch (SB) dilation. This bench study aimed to evaluate the impact of stent link location and stent design on stent deformation, obstruction by stent struts at a jailed SB ostium, and incomplete stent apposition in the proximal optimization technique (POT)-PBED procedure. A coronary bifurcation model was used. We intentionally set the absence or presence of stent link on the carina (link-free or link-connect) under videoscope observation and compared stent parameters between 3- and 2-link stents (n = 5 each, n = 20 total). In the link-free group, the SB jailing rate of 3-link stents was significantly higher than that of 2-link stents (15.5 ± 5.1% vs. 6.6 ± 1.2%, p = 0.009). In the link-connect group, the SB jailing rate of 3-link stents was significantly lower than that of 2-link stents (30.0 ± 4.5% vs. 39.0 ± 2.6%, p = 0.009). In the bifurcation segment, the rate of incomplete stent apposition was significantly lower for 3-link stents of the link-connect group than for 2-link stents of the link-connect group (3.3 ± 4.2% vs. 19.0 ± 7.8%, p = 0.009). For both stent designs, ellipticity ratio was higher for link-connect group than link-free group. Link location as well as stent cell design greatly impacted stent deformation during the POT-PBED procedure.

Experimental validation and clinical feasibility of 3D reconstruction of coronary artery bifurcation stents using intravascular ultrasound.

The structural morphology of coronary stents and the local hemodynamic environment following stent deployment in coronary arteries are crucial determinants of procedural success and subsequent clinical outcomes. High-resolution intracoronary imaging has the potential to facilitate geometrically accurate three-dimensional (3D) reconstruction of coronary stents. This work presents an innovative algorithm for the 3D reconstruction of coronary artery stents, leveraging intravascular ultrasound (IVUS) and angiography. The accuracy and reproducibility of our method were tested in stented patient-specific silicone models, with micro-computed tomography serving as a reference standard. We also evaluated the clinical feasibility and ability to perform computational fluid dynamics (CFD) studies in a clinically stented coronary bifurcation. Our experimental and clinical studies demonstrated that our proposed algorithm could reproduce the complex 3D stent configuration with a high degree of precision and reproducibility. Moreover, the algorithm was proved clinically feasible in cases with stents deployed in a diseased coronary artery bifurcation, enabling CFD studies to assess the hemodynamic environment. In combination with patient-specific CFD studies, our method can be applied to stenting optimization, training in stenting techniques, and advancements in stent research and development.

Acute hypoxemia caused by Impella in a patient with fulminant myocarditis and patent foramen ovale.

Impella ™ (Abiomed, Danvers, MA, USA) is effective in the acute management of fulminant myocarditis and myocardial infarction with cardiogenic shock. Here, we report a case of a 70-year-old man with fulminant myocarditis in cardiogenic shock who developed right-left shunt via patent foramen ovale during acute management with Impella 5.0, resulting in sudden hypoxemia. With combined support of veno-arterial extracorporeal membrane oxygenation and Impella (ECPELLA), his circulation and oxygenation became stable. The same phenomenon is well known in left ventricular assist device. In such situations, ECPELLA is effective to improve the hypoxic condition. It should be kept in mind that hypoxemia can occur in patients with intracardiac shunt disease when using Impella. Learning objective: Impella is effective to maintain circulation in patients with cardiogenic shock; however, several complications have been reported. Intra-cardiac shunt can suddenly cause severe hypoxemia by Impella. We should mention the presence of intra-cardiac shunt, if the patients have sudden hypoxemia when using left ventricular assist.

Impact of Medina classification on clinical outcomes of imaging-guided coronary bifurcation stenting.

Background: Intracoronary imaging improves clinical outcomes after stenting of complex coronary bifurcation lesions (CBLs), but the impact of Medina classification-based CBL distribution on outcomes of imaging-guided bifurcation stenting is unclear. Methods: In this integrated analysis of four previous studies, in which all CBLs were treated with drug-eluting stents under intravascular ultrasound or optical coherence tomography guidance, the distribution of 763 CBLs was assessed using angiographic Medina classification. Major adverse cardiac events (MACE), including target lesion revascularization (TLR), myocardial infarction, stent thrombosis, and cardiac death, were investigated at 1-year follow-up. Results: The most and least prevalent Medina subtypes were 0-1-0 (27.9 %) and 0-0-1 lesions (2.8 %). The most and least frequent MACE/TLR rates were 18.2 %/18.2 % for 0-0-1 lesions and 4.1 %/2.8 % for 0-1-0 lesions. Risks were higher for 0-0-1 lesions than for 0-1-0 lesions for both MACE (hazard ratio [HR]: 4.04, 95 % confidence interval [CI]: 1.21-13.45, p = 0.02) and TLR (HR: 6.19, 95 % CI: 1.69-22.74, p = 0.006). MACE rates were similar for true and non-true CBLs excluding 0-0-1 lesions (8.2 % and 5.9 %, HR 1.54, 95 % CI: 0.86-2.77, p = 0.15), while MACE (HR: 3.25, 95 % CI: 1.10-9.63, p = 0.03) and TLR (HR: 4.24, 95 % CI: 1.38-12.96, p = 0.01) risks were higher for 0-0-1 lesions. Conclusions: This integrated analysis of imaging-guided bifurcation stenting demonstrated similar clinical outcomes in true and non-true CBLs, except for 0-0-1 lesions, which had a significantly higher risk of MACE/TLR.

Serial changes of the side-branch ostial area after single crossover stenting with kissing-balloon inflation.

PURPOSE: We aimed to investigate the serial change of the side-branch ostial area (SBOA) depended on the wire-position before Kissing-balloon inflation (KBI) in the single-stent strategy for bifurcation lesions separately in the left main coronary artery (LMCA) and in non-LMCA. METHODS: Patients who underwent a single-stent KBI for a bifurcation lesion and had OCT images at the timing of the rewiring, at the post-procedure, and at the 9-month follow-up were extracted from the 3D-OCT Bifurcation Registry, which is a multicenter-prospective registry of patients with a percutaneous coronary intervention for a bifurcation lesion under OCT guidance. The SBOA was measured by dedicated software, and the rewiring position at the side-branch ostium after crossover stenting was assessed by three-dimensional-optical coherence tomography (3D-OCT). The optimal rewiring was defined as link-free-type and distal rewiring. The relationship between the optimal rewiring and the serial change of the SBOA was investigated separately in LMCA and non-LMCA cases. RESULTS: We examined 75 bifurcation lesions (LMCA, n = 35; non-LMCA, n = 40). The serial changes of the SBOA with the optimal rewiring were not significantly different regardless of LMCA and non-LMCA (LMCA:3.96 to 3.73 mm2, p = 0.38; non-LMCA:2.16 to 2.21 mm2, p = 0.98), whereas the serial changes of the SBOA with the sub-optimal rewiring were significantly reduced (LMCA:6.75 to 5.54 mm2, p = 0.013; non-LMCA:2.28 mm2 to 2.09 mm2, p = 0.024). There was no significant difference in clinical events between the optimal and sub-optimal rewiring group regardless of the LMCA and non-LMCA. CONCLUSION: The side-branch ostial area dilated with the optimal rewiring position in a bifurcation lesion treated with single crossover stenting and kissing-balloon inflation was preserved regardless of whether the bifurcation was in the LMCA or a non-LMCA.

Impact of coronary bifurcation angle on stent malapposition in a randomized comparison between proximal optimization technique followed by side branch dilatation and kissing balloon inflation.

Background: The impact of coronary bifurcation angle (BA) on incomplete stent apposition (ISA) after crossover stenting followed by side branch (SB) intervention has not been established. Methods: A total of 100 crossover stentings randomly treated with proximal optimization technique followed by short balloon dilation in the SB (POT-SBD group, 48 patients) and final kissing balloon technique (KBT group, 52 patients) were analyzed in the PROPOT trial. Major ISA with maximum distance > 400 µm and its location was determined using optical coherence tomography before SB intervention and at the final procedure. The BA was defined as the angle between the distal main vessel and SB. Optimal POT was determined when the difference in stent volume index between the proximal and distal bifurcation was greater than the median value (0.86 mm3/mm) before SB intervention. Result: Major ISA was more frequently observed in the POT-SBD than in the KBT group (35% versus 17%, p < 0.05). In the POT-SBD group, worsening ISA after SBD was prominent at the distal bifurcation. The BA was an independent predictor of major ISA (odds ratio 1.04, 95% confidence interval 1.00-1.07, p < 0.05) with a cut-off value of 59.5° (p < 0.05). However, the cases treated with optimal POT in the short BA (<60°) indicated the lowest incidence of major ISA. In the KBT group, BA had no significant impact. Conclusion: A wide BA has a potential risk for the occurrence of major ISA after POT followed by SBD in coronary bifurcation stenting.

Stent underexpansion is associated with high wall shear stress: a biomechanical analysis of the shear stent study.

Coronary stent underexpansion is associated with restenosis and stent thrombosis. In clinical studies of atherosclerosis, high wall shear stress (WSS) has been associated with activation of prothrombotic pathways, upregulation of matrix metalloproteinases, and future myocardial infarction. We hypothesized that stent underexpansion is predictive of high WSS. WSS distribution was investigated in patients enrolled in the prospective randomized controlled study of angulated coronary arteries randomized to undergo percutaneous coronary intervention with R-ZES or X-EES. WSS was calculated from 3D reconstructions of arteries from intravascular ultrasound (IVUS) and angiography using computational fluid dynamics. A logistic regression model investigated the relationship between WSS and underexpansion and the relationship between underexpansion and stent platform. Mean age was 63±11, 78% were male, 35% had diabetes, mean pre-stent angulation was 36.7°±14.7°. Underexpansion was assessed in 83 patients (6,181 IVUS frames). Frames with stent underexpansion were significantly more likely to exhibit high WSS (> 2.5 Pa) compared to those without underexpansion with an OR of 2.197 (95% CI = [1.233-3.913], p = 0.008). There was no significant association between underexpansion and low WSS (< 1.0 Pa) and no significant differences in underexpansion between R-ZES and X-EES. In the Shear Stent randomized controlled study, underexpanded IVUS frames were more than twice as likely to be associated with high WSS than frames without underexpansion.

Artificial Intelligence, Computational Simulations, and Extended Reality in Cardiovascular Interventions.

Artificial intelligence, computational simulations, and extended reality, among other 21st century computational technologies, are changing the health care system. To collectively highlight the most recent advances and benefits of artificial intelligence, computational simulations, and extended reality in cardiovascular therapies, we coined the abbreviation AISER. The review particularly focuses on the following applications of AISER: 1) preprocedural planning and clinical decision making; 2) virtual clinical trials, and cardiovascular device research, development, and regulatory approval; and 3) education and training of interventional health care professionals and medical technology innovators. We also discuss the obstacles and constraints associated with the application of AISER technologies, as well as the proposed solutions. Interventional health care professionals, computer scientists, biomedical engineers, experts in bioinformatics and visualization, the device industry, ethics committees, and regulatory agencies are expected to streamline the use of AISER technologies in cardiovascular interventions and medicine in general.

Natural history of side branches jailed by drug-eluting stents.

BACKGROUND: Stent deployment across side branch (SB) ostium is common in daily practice. The present study investigated the natural history of SBs jailed by drug-eluting stents (DES). METHODS: The thrombolysis in myocardial infarction (TIMI) flow grades of 271 consecutive SBs jailed by DES in 196 patients was assessed immediately after the procedure and at 9 months of follow-up. Patients receiving any SB intervention were excluded. RESULTS: Of 271 jailed SBs, occlusion occurred in 6.27% and deterioration of flow occurred in 6.27% immediately after stenting. In patients with these SB changes, periprocedural myocardial infarction was more likely than in those without (10.0% vs. 1.8%, P = 0.017), while there was no increase of cardiac death or life-threatening complications such as stent thrombosis and Q-wave myocardial infarction (Q MI) during follow-up. At 9 months, angiography showed that one-third of the initially obstructed SBs were still occluded. In contrast, flow was maintained in almost all (98.6%) SBs with early TIMI flow grade 3 and there was no delayed occlusion of these branches. Multiple regression analysis showed that lesion complexity (Medina bifurcation class, calcification, and preprocedural TIMI grade 2 flow in the SB) and technical factors (jailing by overlapping stents) were related to SB occlusion or flow deterioration. CONCLUSIONS: Jailed SBs showing good flow after stenting had a favorable angiographic and clinical outcome after 9 months of follow-up. However, preprocedural lesion complexity and technical factors should be considered to avoid SB occlusion/flow deterioration associated with periprocedural myocardial infarction.