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.

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.

Health literacy and health care experiences of migrant workers during the COVID-19 pandemic: a qualitative study.

BACKGROUND: Migrant workers are among the most vulnerable populations in society. This study explored the health-literacy experiences of migrant workers in South Korea and how the workers'daily lives have been affected by the coronavirus disease 2019 (COVID-19) pandemic. METHODS: We conducted a series of semi-structured individual and focus-group interviews with 23 migrant workers (eight Cambodians, six Nepalese, four Sri Lankans, three Bangladeshis, and two Pakistanis) residing in the Daegu and Busan metropolitan areas of South Korea. All interviews were digitally recorded and transcribed verbatim. The data were analyzed using content analysis. RESULTS: Migrant workers had difficulty accessing and using health care services due, in large part, to linguistic barriers and a lack of an adequate support system. Four main themes were identified: difficulty understanding and using medical services, obtaining necessary health and safety information, the impact of COVID-19, and protecting oneself from becoming infected with COVID-19. Most workers depended on information from social networking services (SNS) and co-workers. CONCLUSIONS: Migrant workers' difficulty with health care access was exacerbated during the COVID-19 pandemic. The findings suggest the necessity of enhancing migrant workers' health literacy, along with the use of SNS as a viable pathway for sharing health information and resources.

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.

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.

Assessing of the audiovisual patient educational materials on diabetes care with PEMAT.

OBJECTIVE: The purpose of this study was to evaluate the understandability and actionability of audiovisual educational materials on diabetes in Korea using the Patient Education Materials Evaluation Tool (PEMAT), as well as determine the usefulness of these materials. METHODS: A total of 85 audiovisual materials were collected from Korean websites of territory general hospitals, national health institutions, research associations, and major search engines relating to diabetes that were created between 2006 and 2015. Of these, 34 materials that met the inclusion and exclusion criteria were analyzed. Five trained researchers evaluated the materials independently. RESULTS: More than half of the materials (58.8%) had been created by nongovernment organizations. Slightly more than half (n = 19) of the audiovisual materials were streaming-style animation. The average PEMAT score (58.5%) for these materials was moderate. Compared to "understandability" ratings (49.5%), "actionability" ratings were low (31.4%); indeed, fourteen materials had an actionability of 0%. The average usefulness score of the materials was 4.3 points out of a possible 7. There were few suitable audiovisual materials for patient education on diabetes. CONCLUSIONS: These findings will be useful for developing new audiovisual educational materials for diabetes patients with high understandability, actionability, and usefulness.

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.).

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.

Feasibility of dynamic stress 201Tl/rest 99mTc-tetrofosmin single photon emission computed tomography for quantification of myocardial perfusion reserve in patients with stable coronary artery disease.

PURPOSE: We evaluated the feasibility of dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT imaging using a cardiac camera equipped with cadmium-zinc-telluride detectors for the quantification of myocardial perfusion reserve (MPR). METHODS: Subjects with stable known or suspected coronary artery disease (CAD) who had undergone or were scheduled to undergo fractional flow reserve (FFR) measurement were prospectively enrolled. Dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT imaging was performed using a dedicated multiple pinhole SPECT camera with cadmium-zinc-telluride detectors. MPR was derived using Corridor4DM software. RESULTS: A total of 34 subjects were enrolled (25 men and 9 women; mean age 60.4 years). FFR was measured in 65 coronary arteries with intermediate lesions. The average global MPR was 2.58 ± 1.03. Global MPR was associated with the extent of CAD (P = 0.028) and global summed stress score (r = -0.60, P < 0.001). Regional MPR showed a significant correlation with diameter stenosis (r = -0.57, P < 0.001), minimum lumen diameter (r = 0.50, P < 0.001), summed stress score (r = -0.52, P < 0.001) and FFR (r = 0.52, P < 0.001). The area under the receiver operating characteristic curve of MPR for the diagnosis of functionally significant stenosis (FFR ≤0.8) was 0.79 (P < 0.001). The sensitivity and specificity of regional MPR were 67% and 83%, respectively, using a cut-off value of 2.0. CONCLUSION: Dynamic stress 201Tl/rest 99mTc-tetrofosmin SPECT imaging and quantification of MPR is feasible in patients with stable CAD. The preliminary results of this study in a small number of patients require confirmation in a larger cohort to determine their implications for bolstering the role of SPECT imaging in the diagnosis and risk prediction of CAD.

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.

Value of intravascular ultrasound in guiding coronary interventions.

There has been great effort to improve clinical outcome in percutaneous treatment for coronary artery disease. Complementary to coronary angiography, intravascular ultrasound (IVUS) provides in vivo tomographic anatomic information, enabling to evaluate from the lumen to the vessel wall. As a result, IVUS has had a pivotal role to understand pathophysiology of coronary artery disease and improve clinical outcome. It provides preprocedural information to evaluate stenosis severity and plaque characteristics and helps with optimal stent deployment, minimizing underexpansion and geographic miss that are the major mechanisms of stent failure. Recently, many large-scale clinical trials and meta-analyses with drug-eluting stents have shown the clinical benefits of IVUS-guided percutaneous coronary intervention. Some recent studies have also supported the cost-effectiveness of IVUS-guided PCI especially in high-risk patients. This article will discuss the clinical value of IVUS in contemporary practice.

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.

Long-term outcomes of bypass grafting versus drug-eluting stenting for left main coronary artery disease: Results from the IRIS-MAIN registry.

There are limited data on comparative outcomes and its determinants following coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for left main coronary artery disease (LMCAD) in a real-world setting. METHODS: A total of 3,504 consecutive patients with LMCAD treated with CABG (n=1,301) or PCI with DES (n=2,203) from the IRIS-MAIN registry were analyzed. The relative treatment effect of one strategy over another was assessed by propensity-score matching method. The primary outcome was a composite of death, myocardial infarction, or stroke. RESULTS: Median follow-up duration was 4.7 years. In the matched cohort, both groups demonstrated a similar risk for the primary outcome (adjusted hazard ratio [HR]: 0.94; 95% CI: 0.77-1.15; P=.54). Compared with CABG, PCI exhibited higher risks of myocardial infarction (HR: 2.11; 95% CI: 1.16-3.83; P=.01) and repeated revascularization (HR: 5.95; 95% CI: 3.94-8.98; P<.001). In the overall population, age, presence of chronic kidney disease, and low ejection fraction (<40%) were key clinical predictors of primary outcome regardless of the treatment strategy. However, factors deemed to be associated with perioperative morbidity were determinants of primary outcome in the CABG group, whereas those generally associated with the severity of atherosclerotic coronary artery disease were strong predictors in the PCI group. CONCLUSIONS: Among patients with significant LMCAD, the long-term risk of the composite outcome of death, myocardial infarction, or stroke was similar between CABG and PCI. Clinical variables that differentially predict adverse outcomes might be useful in triaging appropriate revascularization strategy.

Intravascular ultrasound-derived morphological predictors of myocardial ischemia assessed by stress myocardial perfusion computed tomography.

BACKGROUND: Although ischemia-guided revascularization improves clinical outcomes, morphological determinants of clinically relevant myocardial ischemia have not been studied. To identify intravascular ultrasound (IVUS)-derived anatomical parameters for predicting myocardial perfusion defect and its extent. METHODS: A total of 103 patients (88 stable and 15 unstable angina) with 153 lesions (angiographic diameter stenosis of 30-80%) underwent stress myocardial perfusion computed tomography (CT) and IVUS pre-procedure. The volume of CT perfusion defect and %CT perfusion defect in the target vessel territories were measured. RESULTS: The CT perfusion defect was seen in 76 (50%) lesions. The independent determinants for the presence of CT perfusion defect were IVUS-minimal lumen area (MLA) (adjusted OR = 0.56, 95% CI = 0.38-0.82), plaque burden (adjusted OR = 1.07, 95% CI = 1.02-1.11) and involvement of left main or left anterior descending artery (adjusted OR = 4.13, 95% CI = 1.75-9.78, all P < 0.05). The CT perfusion defect was predicted by IVUS-MLA <2.28mm2 (sensitivity 74%, specificity 82%) and plaque burden >77% (sensitivity 79%, specificity 78%) as thresholds. The independent determinants for the volume of CT perfusion defect were the involvement of left main or left anterior descending artery (ß = 16.43, standard errors = 4.387, P = 0.020) and a greater plaque burden (ß = 0.56, standard errors = 0.163, P = 0.026). CONCLUSIONS: IVUS-derived morphological parameters were useful to predict the presence of CT perfusion defect and the size of myocardial ischemia that were primarily determined by lesion severity and subtended myocardial territory. © 2016 Wiley Periodicals, Inc.

Myocardial segmentation based on coronary anatomy using coronary computed tomography angiography: Development and validation in a pig model.

OBJECTIVES: To validate a method for performing myocardial segmentation based on coronary anatomy using coronary CT angiography (CCTA). METHODS: Coronary artery-based myocardial segmentation (CAMS) was developed for use with CCTA. To validate and compare this method with the conventional American Heart Association (AHA) classification, a single coronary occlusion model was prepared and validated using six pigs. The unstained occluded coronary territories of the specimens and corresponding arterial territories from CAMS and AHA segmentations were compared using slice-by-slice matching and 100 virtual myocardial columns. RESULTS: CAMS more precisely predicted ischaemic area than the AHA method, as indicated by 95% versus 76% (p < 0.001) of the percentage of matched columns (defined as percentage of matched columns of segmentation method divided by number of unstained columns in the specimen). According to the subgroup analyses, CAMS demonstrated a higher percentage of matched columns than the AHA method in the left anterior descending artery (100% vs. 77%; p < 0.001) and mid- (99% vs. 83%; p = 0.046) and apical-level territories of the left ventricle (90% vs. 52%; p = 0.011). CONCLUSIONS: CAMS is a feasible method for identifying the corresponding myocardial territories of the coronary arteries using CCTA. KEY POINTS: • CAMS is a feasible method for identifying corresponding coronary territory using CTA • CAMS is more accurate in predicting coronary territory than the AHA method • The AHA method may underestimate the ischaemic territory of LAD stenosis.