Comparable humoral and cellular immunity against Omicron variant BA.4/5 of once-boosted BA.1/2 convalescents and twice-boosted COVID-19-naïve individuals.

The fourth vaccination dose confers additional protective immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in individuals with no prior coronavirus disease-19 (COVID-19). However, its immunological benefit against currently circulating BA.4/5 is unclear in individuals who have received a booster shot and been infected with Omicron variant BA.1/2. We analyzed immune responses in whom had been boosted once and did not have COVID-19 (n = 16), boosted once and had COVID-19 when BA.1/2 was dominant in Korea (Hybrid-6M group, n = 27), and boosted twice and did not have COVID-19 (Vx4 group, n = 15). Antibody binding activities against RBDo BA.1 and RBDo BA.4/5 , antigen-specific memory CD4+ and CD8+ T-cell responses against BA.4/5, and B-cell responses against SARS-CoV-2 wild-type did not differ statistically between the Hybrid-6M and Vx4 groups. The humoral and cellular immune responses of the Hybrid-6M group against BA.4/5 were comparable to those of the Vx4 group. Individuals who had been boosted and had an Omicron infection in early 2022 may not have high priority for an additional vaccination.

Machine Learning-Based prediction of Post-Treatment ambulatory blood pressure in patients with hypertension.

Purpose. Pre-treatment prediction of individual blood pressure (BP) response to anti-hypertensive medication is important to determine the specific regimen for promptly and safely achieving a target BP. This study aimed to develop supervised machine learning (ML) models for predicting patient-specific treatment effects using 24-hour ambulatory BP monitoring (ABPM) data.Materials and Methods. A total of 1,129 patients who had both baseline and follow-up ABPM data were randomly assigned into training, validation and test sets in a 3:1:1 ratio. Utilising the features including clinical and laboratory findings, initial ABPM data, and anti-hypertensive medication at baseline and at follow-up, ML models were developed to predict post-treatment individual BP response. Each case was labelled by the mean 24-hour and daytime BPs derived from the follow-up ABPM.Results. At baseline, 616 (55%) patients had been treated using mono or combination therapy with 45 anti-hypertensive drugs and the remaining 513 (45%) patients had been untreated (drug-naïve). By using CatBoost, the difference between predicted vs. measured mean 24-hour systolic BP at follow-up was 8.4 ± 7.0 mm Hg (% difference of 6.6% ± 5.7%). The difference between predicted vs. measured mean 24-hour diastolic BP was 5.3 ± 4.3 mm Hg (% difference of 6.8% ± 5.5%). There were significant correlations between the CatBoost-predicted vs. the ABPM-measured changes in the mean 24-hour Systolic (r = 0.74) and diastolic (r = 0.68) BPs from baseline to follow-up. Even in the patients with renal insufficiency or diabetes, the correlations between CatBoost-predicted vs. ABPM-measured BP changes were significant.Conclusion. ML algorithms accurately predict the post-treatment ambulatory BP levels, which may assist clinicians in personalising anti-hypertensive treatment.

The prediction of post-treatment BP response is essential to plan the appropriate optimal treatment strategy for achieving the target BP level.The poor predictability of the post-treatment BP level is due to the complex pathophysiology of individual BP response, which can partly explain the poor rate to achieve the target systolic BP.In this current study including both treated and untreated patients with hypertension, machine leaning models predicted the post-treatment mean BP levels on 24-hr ABPM even in high-risk patients and patients with a high BP variability.Model-derived selection and optimisation of anti-hypertension drugs may facilitate prompt achievement of adequate BP control without drug-related complications and avoiding repeating 24-hour ABPM or multiple visits for drug readjustment.

Engineering a U-box of E3 ligase E4B through yeast surface display-based functional screening generates a variant with enhanced ubiquitin ligase activity.

Ubiquitination is the covalent attachment of ubiquitin (Ub) to substrate proteins and regulates several cellular processes, including protein degradation. Ub ligases (E3s) bring a Ub-conjugated enzyme E2 (E2-Ub) and the target protein closer to enable ubiquitination. In this study, we engineered a U-box domain of human U-box-type E3 E4B (E4BU) to enhance its function as a Ub ligase by accelerating the rate of Ub transfer directly from Ub-loaded human E2 UbcH5b (E2(UbcH5b)-Ub) to the proximal substrate. We developed a functional screening system for the E4BU library using a yeast surface display system combined with fluorescence-activated cell sorting (FACS) to isolate functionally improved variants. This phenotypic screening system yielded an E4BU variant, E4BU(#8), which exhibited an approximately 4-fold greater Ub ligase activity rate in the yeast displayed form than that of the E4BU wild-type. When E4BU(#8) was fused to a green fluorescent protein (GFP)-specific nanobody, the fusion protein polyubiquitinated GFP in proportion to the concentration and incubation time, with an approximately 3-fold faster Ub ligase activity rate than the previously isolated E4BU(NT) variant. Importantly, the engineered E4BU(#8) retained endogenous Lys48-linked polyubiquitination activity, which is essential for substrate degradation by the 26S proteasome. Our results indicated that E4BU(#8), which binds to and allosterically stimulates E2(UbcH5b)-Ub to enhance Ub transferase activity to a substrate, may be valuable in designing biological molecules for targeted protein degradation.

Primary versus rescue retrograde approach for chronic total coronary occlusion.

OBJECTIVES: We aimed to assess the advantages of using the retrograde approach as an initial strategy rather than as a rescue strategy for complex chronic total occlusions (CTOs). BACKGROUND: Even for complex CTOs where a retrograde approach is deemed necessary, an antegrade approach is frequently used as an initial strategy in real-world practice. METHODS: We evaluated 352 retrograde procedures for CTO conducted at our high-volume center between January 2007 and January 2019. Procedural efficiency and safety was assessed based on the guidewire manipulation time (GWMT) and the occurrence of procedure-related adverse events for the primary retrograde approach (PRA) and the rescue retrograde approach (RRA). RESULTS: PRA and RRA were used in 191 (54.3%) and 161 (45.7%) of the CTO procedures, respectively. The complexity of the CTO lesion was significantly higher in the PRA group than in the RRA group (Japanese-CTO score, 2.62 ± 1.07 vs. 2.38 ± 1.06, p = 0.037). The technical success rate of two groups was similar (p = 0.47). The median GWMT required for PRA was significantly shorter than that for RRA (85 [interquartile range, 55-126] vs. 120 [85-157] min, p < 0.001). The total duration of the procedure and fluoroscopic time were shorter, and the number of guidewires and amount of contrast used during the index procedure were smaller in the PRA group. The incidence of procedure-related adverse events was not significantly different between the two groups. CONCLUSIONS: PRA showed higher procedural efficiency than RRA with comparable safety. Opting for PRA for complex CTOs might be a rational decision to enhance the procedural efficiency.

Engineering of an EpCAM-targeting cyclic peptide to improve the EpCAM-mediated cellular internalization and tumor accumulation of a peptide-fused antibody.

Fusion of a target-specific peptide to a full-length antibody (Ab) can result in a peptide-Ab fusion protein with additional specificity and enhanced activity. We recently developed an intracellular pan-RAS-targeting cytosol-penetrating antibody, RT22-ep59, in which a tumor-specific targeting ability was achieved via the fusion of an epithelial cell adhesion molecule (EpCAM) targeting cyclic peptide (ep133). Here, the aim was to enhance EpCAM-mediated endocytosis and tumor accumulation of the peptide-fused RAS-targeting Ab. Accordingly, we engineered a cyclic peptide (from ep133) that has stronger affinity for EpCAM by using yeast surface display technology and then rationally designed cyclic peptides in the Ab-fused form to enhance colloidal stability. The finally engineered EpCAM-targeting cyclic peptide (ep6)-fused Ab, ep6Ras37, has ∼10-fold stronger affinity (KD ≈ 1.9 nM) for EpCAM than that of RT22-ep59, without deterioration of biophysical properties. Compared with the parental antibody (RT22-ep59), ep6Ras37 more efficiently reached the cytosol of EpCAM-expressing cells and showed greater preferential tumor homing and accumulation in mice bearing EpCAM-expressing LoVo xenograft tumors. Thus, the high-affinity EpCAM-targeting peptide ensures efficient cellular internalization and better tumor accumulation of the peptide-fused Ab.

Comparison of simple versus complex stenting in patients with true distal left main bifurcation lesions.

INTRODUCTION: Distal left main (LM) bifurcation disease is one of the most challenging lesion subsets for percutaneous coronary intervention (PCI) and optimal stenting strategy for such complex lesions is still debated. This study aimed to compare clinical outcomes following single versus dual stenting for true distal LM bifurcation lesions. METHODS: Patients with true distal LM bifurcation lesions (type 1,1,1 or 0,1,1: both left anterior descending and circumflex artery >2.5 mm diameter) receiving PCI with drug-eluting stents (DES) from two large clinical registries were evaluated. The primary outcome was target-lesion failure (TLF), defined as a composite of cardiac death, target-vessel myocardial infarction (MI), or target-lesion revascularization (TLR). Outcomes were compared with the use of propensity scores and inverse probability-weighting adjustment to reduce treatment selection bias. RESULTS: Among 1,002 patients undergoing true distal LM PCI, 440 (43.9%) and 562 (56.1%) were treated with single and dual stents, respectively. The TLF rates at 3 year was 20.3% in the single-stent group and 24.1% in the dual-stenting group (log-rank p = 0.18). The adjusted risk for TLF did not differ significantly between two groups (hazard ratio [HR] with dual-stent vs. single-stent: 1.27, 95% confidence interval [CI]: 0.95-1.71). The adjusted risks for death, MI, repeat revascularization, or stent thrombosis were also similar between the single- and dual-stenting groups. CONCLUSIONS: In patients undergoing PCI for true distal LM disease, single- and dual-stent strategies showed a similar adjusted risk of TLF at 3 years. Our findings should be confirmed or refuted through large, randomized clinical trials.

Clinically Significant Bleeding With Ticagrelor Versus Clopidogrel in Korean Patients With Acute Coronary Syndromes Intended for Invasive Management: A Randomized Clinical Trial.

BACKGROUND: Owing to the differential propensity for bleeding and ischemic events with response to antiplatelet therapy, the safety and effectiveness of potent P2Y12 inhibitor ticagrelor in East Asian populations remain uncertain. METHODS: In this multicenter trial, 800 Korean patients hospitalized for acute coronary syndromes with or without ST elevation and intended for invasive management were randomly assigned to receive, in a 1:1 ratio, ticagrelor (180 mg loading dose, 90 mg twice daily thereafter) or clopidogrel (600 mg loading dose, 75 mg daily thereafter). The primary safety outcome was clinically significant bleeding (a composite of major bleeding or minor bleeding according to PLATO (Platelet Inhibition and Patient Outcomes) criteria at 12 months. RESULTS: At 12 months, the incidence of clinically significant bleeding was significantly higher in the ticagrelor group than in the clopidogrel group (11.7% [45/400] vs 5.3% [21/400]; hazard ratio [HR], 2.26; 95% confidence interval [CI], 1.34 to 3.79; P=0.002). The incidences of major bleeding (7.5% [29/400] vs 4.1% [16/400], P=0.04) and fatal bleeding (1% [4/400] vs 0%, P=0.04) were also higher in the ticagrelor group. The incidence of death from cardiovascular causes, myocardial infarction, or stroke was not significantly different between the ticagrelor group and the clopidogrel group (9.2% [36/400] vs 5.8% [23/400]; HR, 1.62; 95% CI, 0.96 to 2.74; P=0.07). Overall safety and effectiveness findings were similar with the use of several different analytic methods and in multiple subgroups. CONCLUSIONS: In Korean acute coronary syndrome patients intended to receive early invasive management, standard-dose ticagrelor as compared with clopidogrel was associated with a higher incidence of clinically significant bleeding. The numerically higher incidence of ischemic events should be interpreted with caution, given the present trial was underpowered to draw any conclusion regarding efficacy. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02094963.

Randomized Trial Evaluating Percutaneous Coronary Intervention for the Treatment of Chronic Total Occlusion.

BACKGROUND: Procedural results for percutaneous coronary intervention (PCI) in coronary vessels with chronic total occlusion (CTO) have improved in recent years, and PCI strategies have moved toward more complete revascularization with more liberal use of CTO-PCI. However, evidence evaluating CTO-PCI is limited to observational studies and small clinical trials. METHODS: In this open-label, multicenter, randomized, noninferiority trial, PCI-eligible patients were assigned to receive either 1 of 2 strategies: PCI or no PCI for the qualifying de novo CTO lesion with the option for PCI of obstructive non-CTO lesions at the discretion of the operator. The primary end point was a composite of death, myocardial infarction, stroke, or any revascularization. Health-related quality of life was assessed at baseline and at 1, 6, 12, 24, and 36 months. Because of slow recruitment, the trial was stopped before completion of the 1284 planned enrollments. RESULTS: Between March 2010 and September 2016, 834 patients were randomly assigned to the CTO-PCI (n=417) or no CTO-PCI (n=398) strategy. Among the patients assigned to the no CTO-PCI strategy, 78 (19.6%) crossed over to receive staged CTO-PCI within 3 days of randomization. The overall CTO-PCI success rate was 90.6%. Serious nonfatal complications associated with CTO-PCI occurred in 3 patients (1 stroke, 1 cardiac tamponade, and 1 patient with recurrent episodes of ventricular tachyarrhythmia induced by intracoronary thrombus). Approximately half of the patients in each group underwent PCI for an average of 1.3 non-CTO lesions, resulting in a comparable residual SYNTAX score (Synergy Between PCI With TAXUS and Cardiac Surgery; 3.7±5.4 versus 4.0±5.9, P=0.42) confined to non-CTO vessels. During a median follow-up of 4.0 years (interquartile range, 2.4 to 5.1 years), there was no significant difference between the CTO-PCI and the no CTO-PCI strategies in the incidence of the primary end point (22.3% versus 22.4%, hazard ratio, 1.03; 95% CI, 0.77 to 1.37; P=0.86). Both CTO-PCI and no CTO-PCI strategy were associated with significant improvements but without between-group differences in disease-specific health status that was sustained through 36 months. CONCLUSIONS: CTO-PCI was feasible with high success rates. There was no difference in the incidence of major adverse cardiovascular events with CTO-PCI versus no CTO-PCI, but the study was limited by low power for clinical end points and high crossover rates between groups. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01078051.

Comparison of optical coherence tomography-guided versus intravascular ultrasound-guided percutaneous coronary intervention: Rationale and design of a randomized, controlled OCTIVUS trial.

BACKGROUND: The clinical value of intracoronary imaging for percutaneous coronary intervention (PCI) guidance is well acknowledged. Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) are the most commonly used intravascular imaging to guide and optimize PCI in day-to-day practice. However, the comparative effectiveness of IVUS-guided versus OCT-guided PCI with respect to clinical end points remains unknown. METHODS AND DESIGN: The OCTIVUS study is a prospective, multicenter, open-label, parallel-arm, randomized trial comparing the effectiveness of 2 imaging-guided strategies in patients with stable angina or acute coronary syndromes undergoing PCI in Korea. A total of 2,000 patients are randomly assigned in a 1:1 ratio to either an OCT-guided PCI strategy or an IVUS-guided PCI strategy. The trial uses a pragmatic comparative effectiveness design with inclusion criteria designed to capture a broad range of real-world patients with diverse clinical and anatomical features. PCI optimization criteria are predefined using a common algorithm for online OCT or IVUS. The primary end point, which was tested for both noninferiority (margin, 3.1 percentage points for the risk difference) and superiority, is target-vessel failure (cardiac death, target-vessel myocardial infarction, or ischemia-driven target-vessel revascularization) at 1 year. RESULTS: Up to the end of July 2020, approximately 1,200 "real-world" PCI patients have been randomly enrolled over 2 years. Enrollment is expected to be completed around the midterm of 2021, and primary results will be available by late 2022 or early 2023. CONCLUSION: This large-scale, multicenter, pragmatic-design clinical trial will provide valuable clinical evidence on the relative efficacy and safety of OCT-guided versus IVUS-guided PCI strategies in a broad population of patients undergoing PCI in the daily clinical practice.

Clinical outcomes of contemporary drug-eluting stents in patients with and without diabetes mellitus: Multigroup propensity-score analysis using data from stent-specific, multicenter, prospective registries.

BACKGROUND: Whether the diabetic status differentially affects the clinical outcomes with different drug-eluting stents (DES) has been controversial. METHODS AND RESULTS: From stent-specific, prospective DES registries, we evaluated 17,184 patients (11,428 in non-diabetics and 5,756 in diabetics) who received several contemporary DES: 3570 sirolimus-eluting stents (SES), 5,023 cobalt-chromium everolimus-eluting stents (CoCr-EES), 2,985 platinum-chromium EES (PtCr-EES), 2,913 Resolute zotarolimus-eluting stents (Re-ZES), and 2,693 biodegradable-polymer biolimus-eluting stents (BP-BES). The primary outcome was patient-oriented composite endpoint (POCE, a composite of all-cause death, any myocardial infarction, and any revascularization) at 3-year follow-up and target-vessel failure (a composite of cardiac death, target-vessel myocardial infarction, and target-vessel revascularization) at 3 years was also evaluated. In non-diabetics, the rates of POCE were not significantly different (CoCr-EES 14.3%, PtCr-EES 13.0%, Re-ZES 14.3%, BP-BES 13.4%, and SES 14.6%; overall p = .39). In diabetics, similar results were revealed (CoCr-EES 18.4%, PtCr-EES 20.3%, Re-ZES 17.3%, BP-BES 17.7%, and SES 17.8%; overall p = .44). In multiple treatment propensity-score weighting analysis, regardless of the diabetic status, the hazard ratios for POCE between-individual comparison were similar. Target-vessel failure (a composite of cardiac death, target-vessel myocardial infarction, and target-vessel revascularization) was also comparable except the higher ratio of Re-ZES than PtCr-EES (hazard ratio 1.25, 1.26, 95% confidence interval 1.00-1.55, p = .048) in patients without diabetes. CONCLUSIONS: In this clinical-practice registry study, regardless the diabetic status, the 3-year rates of the primary outcome were similar among different types of DES, suggesting no differential clinical response between contemporary DES in patients with or without diabetes.

Long-term (10-year) outcomes of stenting or bypass surgery for acute coronary syndromes and stable ischemic heart disease with unprotected left main coronary artery disease.

BACKGROUND: Acuity of clinical presentation may influence decision making of percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) for left main coronary artery (LMCA) disease. However, it is undetermined whether clinical indication for myocardial revascularization may affect the relative long-term effect after PCI and CABG. METHODS: In the MAIN-COMPARE study including 2,240 patients with LMCA disease treated with PCI (n = 1102) or CABG (n = 1138), we examined interaction between acuity of clinical presentation (acute coronary syndromes [ACS] or non-ACS) and revascularization strategy on 10-year outcomes. Primary outcome was a composite of all-cause death, Q-wave myocardial infarction, or stroke. Secondary outcomes were all-cause death or target vessel revascularization. RESULTS: In overall patients, 1,603 patients (71.6%) presented with ACS and 637 patients (28.4%) presented with non-ACS. The 10-year adjusted risks for primary composite outcome were similar after PCI and CABG among patients who presented with non-ACS (hazard ratio [HR] 1.07; 95% CI 0.71-1.61) and those who presented with ACS (HR 1.00; 95% CI 0.81-1.24) (P for interaction = .29). The adjusted risks of death were also similar between 2 groups in non-ACS (HR 0.98; 95% CI 0.63-1.51) and ACS (HR 1.02; 95% CI 0.81-1.28) patients (P for interaction = .62). The adjusted risks of target vessel revascularization were consistently higher after PCI in non-ACS (HR 6.38; 95% CI 3.14-12.96) and ACS (HR 3.96; 95% CI 2.80-5.60) patients (P for interaction = .39). CONCLUSIONS: In patients with LMCA disease, we have identified no significant interaction between the acuity of clinical indication and the relative treatment effect of PCI versus CABG on 10-year clinical outcomes.

Deferred vs. performed revascularization for coronary stenosis with grey-zone fractional flow reserve values: data from the IRIS-FFR registry.

Aims: The optimal fractional flow reserve (FFR) cut-off value for revascularization is debated. We evaluated the prognosis for deferred and performed revascularization in coronary stenosis with FFR values in the grey zone (0.75-0.80). Methods and results: This study included 1334 native coronary stenosis with grey-zone FFR values in 1334 patients from the prospective multicentre Interventional Cardiology Research In-cooperation Society Fractional Flow Reserve registry. Revascularization was deferred for 683 patients (deferred group) and performed for 651 (performed group). The primary outcome, a composite of death, target-vessel myocardial infarction (MI), and target vessel revascularization (TVR) occurred in 55 (8.1%) patients in the deferred group and 55 (8.4%) in the performed group [adjusted hazard ratio (aHR) 1.05, 95% confidence interval (CI) 0.67-1.66; P = 0.79] during a median follow-up of 2.9 years (interquartile range 1.5-4.1 years). Overall mortality and spontaneous MI did not differ between the groups (mortality 2.5% vs. 2.0%; aHR 0.82, 95% CI 0.34-2.00; P = 0.66; spontaneous MI 0.7% vs. 0.5%; aHR 1.85, 95% CI 0.35-9.75; P = 0.47). Myocardial infarction was significantly higher in the performed group (0.7% vs. 3.2%; aHR 0.27, 95% CI 0.09-0.80; P = 0.02) mainly because of a higher risk of periprocedural MI. Target vessel revascularization was significantly higher in the deferred group (5.7% vs. 3.7%; aHR 2.17, 95% CI 1.17-4.02; P = 0.01). Conclusion: For coronary stenosis with grey-zone FFR, revascularization was not associated with better clinical outcomes. The higher likelihood of periprocedural MI with revascularization was offset by the higher likelihood of TVR with deferral. Trial registration: Clinicaltrials.gov identifier: NCT01366404.

Fractional Flow Reserve and Cardiac Events in Coronary Artery Disease: Data From a Prospective IRIS-FFR Registry (Interventional Cardiology Research Incooperation Society Fractional Flow Reserve).

BACKGROUND: We evaluated the prognosis of deferred and revascularized coronary stenoses after fractional flow reserve (FFR) measurement to assess its revascularization threshold in clinical practice. METHODS: The IRIS-FFR registry (Interventional Cardiology Research In-cooperation Society Fractional Flow Reserve) prospectively enrolled 5846 patients with ≥1coronary lesion with FFR measurement. Revascularization was deferred in 6468 lesions and performed in 2165 lesions after FFR assessment. The primary end point was major adverse cardiac events (cardiac death, myocardial infarction, and repeat revascularization) at a median follow-up of 1.9 years and analyzed on a per-lesion basis. A marginal Cox model accounted for correlated data in patients with multiple lesions, and a model to predict per-lesion outcomes was adjusted for confounding factors. RESULTS: For deferred lesions, the risk of major adverse cardiac events demonstrated a significant, inverse relationship with FFR (adjusted hazard ratio, 1.06; 95% confidence interval, 1.05-1.08; P<0.001). However, this relationship was not observed in revascularized lesions (adjusted hazard ratio, 1.00; 95% confidence interval, 0.98-1.02; P=0.70). For lesions with FFR ≥0.76, the risk of major adverse cardiac events was not significantly different between deferred and revascularized lesions. Conversely, in lesions with FFR ≤0.75, the risk of major adverse cardiac events was significantly lower in revascularized lesions than in deferred lesions (for FFR 0.71-0.75, adjusted hazard ratio, 0.47; 95% confidence interval, 0.24-0.89; P=0.021; for FFR ≤0.70, adjusted hazard ratio 0.47; 95% confidence interval, 0.26-0.84; P=0.012). CONCLUSIONS: This large, prospective registry showed that the FFR value was linearly associated with the risk of cardiac events in deferred lesions. In addition, revascularization for coronary artery stenosis with a low FFR (≤0.75) was associated with better outcomes than the deferral, whereas for a stenosis with a high FFR (≥0.76), medical treatment would be a reasonable and safe treatment strategy. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01366404.

Machine learning assessment of myocardial ischemia using angiography: Development and retrospective validation.

BACKGROUND: Invasive fractional flow reserve (FFR) is a standard tool for identifying ischemia-producing coronary stenosis. However, in clinical practice, over 70% of treatment decisions still rely on visual estimation of angiographic stenosis, which has limited accuracy (about 60%-65%) for the prediction of FFR < 0.80. One of the reasons for the visual-functional mismatch is that myocardial ischemia can be affected by the supplied myocardial size, which is not always evident by coronary angiography. The aims of this study were to develop an angiography-based machine learning (ML) algorithm for predicting the supplied myocardial volume for a stenosis, as measured using coronary computed tomography angiography (CCTA), and then to build an angiography-based classifier for the lesions with an FFR < 0.80 versus ≥ 0.80. METHODS AND FINDINGS: A retrospective study was conducted using data from 1,132 stable and unstable angina patients with 1,132 intermediate lesions who underwent invasive coronary angiography, FFR, and CCTA at the Asan Medical Center, Seoul, Korea, between 1 May 2012 and 30 November 2015. The mean age was 63 ± 10 years, 76% were men, and 72% of the patients presented with stable angina. Of these, 932 patients (assessed before 31 January 2015) constituted the training set for the algorithm, and 200 patients (assessed after 1 February 2015) served as a test cohort to validate its diagnostic performance. Additionally, external validation with 79 patients from two centers (CHA University, Seongnam, Korea, and Ajou University, Suwon, Korea) was conducted. After automatic contour calibration using the caliber of guiding catheter, quantitative coronary angiography was performed using the edge-detection algorithms (CAAS-5, Pie-Medical). Clinical information was provided by the Asan BiomedicaL Research Environment (ABLE) system. The CCTA-based myocardial segmentation (CAMS)-derived myocardial volume supplied by each vessel (right coronary artery [RCA], left anterior descending [LAD], left circumflex [LCX]) and the myocardial volume subtended to a stenotic segment (CAMS-%Vsub) were measured for labeling. The ML for (1) predicting vessel territories (CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA) and CAMS-%Vsub and (2) identifying the lesions with an FFR < 0.80 was constructed. Angiography-based ML, employing a light gradient boosting machine (GBM), showed mean absolute errors (MAEs) of 5.42%, 8.57%, and 4.54% for predicting CAMS-%LAD, CAMS-%LCX, and CAMS-%RCA, respectively. The percent myocardial volumes predicted by ML were used to predict the CAMS-%Vsub. With 5-fold cross validation, the MAEs between ML-predicted percent myocardial volume subtended to a stenotic segment (ML-%Vsub) and CAMS-%Vsub were minimized by the elastic net (6.26% ± 0.55% for LAD, 5.79% ± 0.68% for LCX, and 2.95% ± 0.14% for RCA lesions). Using all attributes (age, sex, involved vessel segment, and angiographic features affecting the myocardial territory and stenosis degree), the ML classifiers (L2 penalized logistic regression, support vector machine, and random forest) predicted an FFR < 0.80 with an accuracy of approximately 80% (area under the curve [AUC] = 0.84-0.87, 95% confidence intervals 0.71-0.94) in the test set, which was greater than that of diameter stenosis (DS) > 53% (66%, AUC = 0.71, 95% confidence intervals 0.65-0.78). The external validation showed 84% accuracy (AUC = 0.89, 95% confidence intervals 0.83-0.95). The retrospective design, single ethnicity, and the lack of clinical outcomes may limit this prediction model's generalized application. CONCLUSION: We found that angiography-based ML is useful to predict subtended myocardial territories and ischemia-producing lesions by mitigating the visual-functional mismatch between angiographic and FFR. Assessment of clinical utility requires further validation in a large, prospective cohort study.

Trial of everolimus-eluting stents or bypass surgery for coronary disease.

BACKGROUND: Most trials comparing percutaneous coronary intervention (PCI) with coronary-artery bypass grafting (CABG) have not made use of second-generation drug-eluting stents. METHODS: We conducted a randomized noninferiority trial at 27 centers in East Asia. We planned to randomly assign 1776 patients with multivessel coronary artery disease to PCI with everolimus-eluting stents or to CABG. The primary end point was a composite of death, myocardial infarction, or target-vessel revascularization at 2 years after randomization. Event rates during longer-term follow-up were also compared between groups. RESULTS: After the enrollment of 880 patients (438 patients randomly assigned to the PCI group and 442 randomly assigned to the CABG group), the study was terminated early owing to slow enrollment. At 2 years, the primary end point had occurred in 11.0% of the patients in the PCI group and in 7.9% of those in the CABG group (absolute risk difference, 3.1 percentage points; 95% confidence interval [CI], -0.8 to 6.9; P=0.32 for noninferiority). At longer-term follow-up (median, 4.6 years), the primary end point had occurred in 15.3% of the patients in the PCI group and in 10.6% of those in the CABG group (hazard ratio, 1.47; 95% CI, 1.01 to 2.13; P=0.04). No significant differences were seen between the two groups in the occurrence of a composite safety end point of death, myocardial infarction, or stroke. However, the rates of any repeat revascularization and spontaneous myocardial infarction were significantly higher after PCI than after CABG. CONCLUSIONS: Among patients with multivessel coronary artery disease, the rate of major adverse cardiovascular events was higher among those who had undergone PCI with the use of everolimus-eluting stents than among those who had undergone CABG. (Funded by CardioVascular Research Foundation and others; BEST ClinicalTrials.gov number, NCT00997828.).

Engineering of a tumor cell-specific, cytosol-penetrating antibody with high endosomal escape efficacy.

The main obstacles for practical uses of cytosol-penetrating peptides and proteins include their lack of cell- or tissue-specific targeting and limited cytosolic access owing to the poor endosomal escape ability. We have previously reported a cytosol-penetrating, human IgG1 antibody TMab4-WYW, generally referred to as a cytotransmab (CT), which reaches the cytosol of living cells but nonspecifically because it is endocytosed via a ubiquitously expressed receptor called heparan sulfate proteoglycan (HSPG). Here, our aim was to construct a next-generation CT with tumor cell specificity and improved endosomal escape efficiency. We first substantially reduced the HSPG-binding activity of TMab4-WYW and then fused a cyclic peptide specifically recognizing tumor-associated epithelial cell adhesion molecule (EpCAM) to the N terminus of the light chain for EpCAM-mediated endocytosis, while maintaining the endosomal escape ability in the light chain variable domain (VL), thus generating epCT05. Then, we separately engineered another CT, dubbed epCT65-AAA, with an endosomal escape ability only in the heavy chain variable domain (VH) but not in VL, by functional grafting of the endosomal escape motif of epCT05 VL to the VH. We finally combined the heavy chain of epCT65-AAA and the light chain of epCT05 to create epCT65 with endosomal escape capacity in both the VH and VL. epCT65 effectively localized to the cytosol of only EpCAM-expressing tumor cells and showed approximately twofold improved endosomal escape efficiency, as compared with CTs with endosomal escape motifs in either VH or VL. The full-IgG format CT, epCT65, with a tumor cell-specific cytosol-penetrating activity, has a great potential for practical medical applications, e.g., as a carrier for cytosolic delivery of payloads.

Comparison of drug-eluting stents and drug-coated balloon for the treatment of drug-eluting coronary stent restenosis: A randomized RESTORE trial.

BACKGROUND: This study sought to evaluate the optimal treatment for in-stent restenosis (ISR) of drug-eluting stents (DESs). METHODS: This is a prospective, multicenter, open-label, randomized study comparing the use of drug-eluting balloon (DEB) versus second-generation everolimus-eluting stent for the treatment of DES ISR. The primary end point was in-segment late loss at 9-month routine angiographic follow-up. RESULTS: A total of 172 patients were enrolled, and 74 (43.0%) patients underwent the angiographic follow-up. The primary end point was not different between the 2 treatment groups (DEB group 0.15±0.49 mm vs DES group 0.19±0.41 mm, P=.54). The secondary end points of in-segment minimal luminal diameter (MLD) (1.80±0.69 mm vs 2.09±0.46 mm, P=.03), in-stent MLD (1.90±0.71 mm vs 2.29±0.48 mm, P=.005), in-segment percent diameter stenosis (34%±21% vs 26%±15%, P=.05), and in-stent percent diameter stenosis (33%±21% vs 21%±15%, P=.002) were more favorable in the DES group. The composite of death, myocardial infarction, or target lesion revascularization at 1 year was comparable between the 2 groups (DEB group 7.0% vs DES group 4.7%, P=.51). CONCLUSIONS: Treatment of DES ISR using DEB or second-generation DES did not differ in terms of late loss at 9-month angiographic follow-up, whereas DES showed better angiographic results regarding minimal MLD and percent diameter stenosis. Both treatment strategies were safe and effective up to 1year after the procedure.

Comparison of long-term mortality according to obesity in patients with successful percutaneous chronic total occlusion interventions using drug-eluting stents.

OBJECTIVE: To evaluate the long-term mortality according to obesity in patients with chronic total occlusion (CTO) lesions after successful percutaneous coronary intervention (PCI). BACKGROUND: Despite the potential impact of coronary revascularization and lesion severity on the obesity paradox, the long-term survival according to obesity in CTO patients after successful PCI has been unknown. METHODS AND RESULTS: Between January 2003 and September 2014, we examined 1,172 consecutive Korean patients with 1,190 CTO lesions who underwent successful drug-eluting stent (DES) implantation in two tertiary academic medical centers. The primary and secondary endpoints were all-cause and cardiac death, respectively. Obesity was defined as a body mass index ≥25.0 kg/m2 , based on the criteria for Asians. The median follow-up time was 4.4 years. The prevalence of obesity was 54.4%. During the follow-up periods, the occurrence of all-cause (6.1 vs. 10.7%) and cardiac death (3.8 vs. 6.7%) was lower in obese patients than in non-obese patients (P <0.05, respectively). Kaplan-Meier analysis showed that obese patients had lower cumulative rates of all-cause and cardiac death than did non-obese patients (log-rank P <0.05, respectively). Univariate Cox regression analysis showed that age ≥65 years (hazard ratio [HR], 3.62), diabetes mellitus (HR, 1.94), renal dysfunction (HR, 7.03), systolic heart failure (HR, 2.61), and obesity (HR, 0.58) were associated with all-cause death (P <0.05). Multivariate Cox regression models showed that high BMI was independently associated with the decreased risk of all-cause death. CONCLUSIONS: Obese patients appear to have a lower long-term mortality than do non-obese patients in CTO after successful PCI using DES. © 2017 Wiley Periodicals, Inc.

Coronary CT angiography characteristics of OCT-defined thin-cap fibroatheroma: a section-to-section comparison study.

OBJECTIVES: To evaluate whether plaque characteristics as assessed by coronary computed tomography angiography (CCTA) were associated with the presence of a thin-cap fibroatheroma (TCFA)-a precursor of plaque rupture-defined by optical coherence tomography (OCT) in a section-to-section-level comparison. METHODS: From 28 symptomatic patients, 31 coronary lesions were evaluated on 727 cross-sections co-registered by both CCTA and OCT. CCTA plaque characteristics included low attenuation plaque (LAP, <30 HU), napkin ring sign (NRS), positive remodelling (PR, remodelling index ≥1.10), and spotty calcification and plaque area and plaque burden. By OCT, presence of TCFA, lumen area and arc of lipid were determined. RESULTS: OCT revealed a TCFA in 69 (9.4%) sections from 19 (61.2 %) lesions. In per-section analysis, OCT-TCFA showed higher frequency of CCTA-detected LAP (58.0% vs. 18.5%), NRS (31.9% vs. 8.8%) and PR (68.1% vs. 48.0%) and greater plaque burden (70.6% vs. 61.9%) as compared to sections without OCT-TCFA (all p < 0.05). In multivariable analysis, LAP (odds ratio [OR] 4.05, p < 0.001) and NRS (OR 2.47, p = 0.005) were associated with OCT-TCFA. CCTA-measured lumen area correlated well with OCT-measured lumen area (R = 0.859, limits of agreement -0.5 ± 3.7 mm2). CONCLUSIONS: LAP and NRS in CCTA were associated with the presence of OCT-defined TCFA in a section-to-section comparison. KEY POINTS: • CT-defined LAP and NRS were associated with OCT-defined TCFA • OCT-TCFA showed higher frequency of LAP, NRS, PR and greater plaque burden • Non-calcified plaque area was correlated with OCT-measured lipid arc.

Fractional flow reserve and pressure-bounded coronary flow reserve to predict outcomes in coronary artery disease.

AIMS: Fractional flow reserve (FFR) has proven to its prognostic and therapeutic value. However, the additive prognostic value of coronary flow reserve (CFR) remains unclear. This study sought to investigate the clinical utility of combined FFR and CFR measurements to predict outcomes. METHODS AND RESULTS: Using the prospective, multicentre Interventional Cardiology Research Incooperation Society-FFR registry, a total of 2088 lesions from 1837 patients were included in this substudy. Based on baseline and hyperaemic pressure gradients, we computed physiologic limits of CFR [the so called pressure-bounded (pb) CFR] and classified lesions as low (<2) or high (≥2). The primary endpoint was major adverse cardiac events (MACE, a composite of cardiac death, myocardial infarction, and revascularization) analysed on a per-patient basis. During a median follow-up of 1.9 years (inter-quartile range: 1.0-3.0 years), MACE occurred in 5.7% of patients with FFR ≤0.80 vs. 2.8% of patients with FFR >0.80 [adjusted hazard ratio (aHR): 2.15, 95% confidence interval (CI): 1.19-3.89; P = 0.011. In contrast, the incidence of MACE did not differ between patients with pb-CFR < 2 vs. pb-CFR ≥ 2 (4.2% vs. 4.2%; aHR: 0.98, CI: 0.60 to 1.58; P = 0.92). Incorporation of FFR significantly improved model prediction of MACE (global χ2 38.8-48.1, P = 0.002). However, pb-CFR demonstrated no incremental utility to classify outcomes (global χ2 48.1-48.2, P > 0.99). CONCLUSIONS: In this large, prospective registry of over 2000 coronary lesions, FFR was strongly associated with clinical outcomes. In contrast, a significant association between pb-CFR and clinical events could not be determined and adding knowledge of pb-CFR did not improve prognostication over FFR alone.