Atrial fibrillation incidence after coronary artery bypass graft surgery and percutaneous coronary intervention: the prospective AFAF cohort study.

Objectives. Atrial fibrillation is a common arrhythmia in patients with ischemic heart disease. This study aimed to determine the cumulative incidence of new-onset atrial fibrillation after percutaneous coronary intervention or coronary artery bypass grafting surgery during 30 days of follow-up. Design. This was a prospective multi-center cohort study on atrial fibrillation incidence following percutaneous coronary intervention or coronary artery bypass grafting for stable angina or non-ST-elevation acute coronary syndrome. Heart rhythm was monitored for 30 days postoperatively by in-hospital telemetry and handheld thumb ECG recordings after discharge were performed. The primary endpoint was the cumulative incidence of atrial fibrillation 30 days after the index procedure. Results. In-hospital atrial fibrillation occurred in 60/123 (49%) coronary artery bypass graft and 0/123 percutaneous coronary intervention patients (p < .001). The cumulative incidence of atrial fibrillation after 30 days was 56% (69/123) of patients undergoing coronary artery bypass grafting and 2% (3/123) of patients undergoing percutaneous coronary intervention (p < .001). CABG was a strong predictor for atrial fibrillation compared to PCI (OR 80.2, 95% CI 18.1-354.9, p < .001). Thromboembolic stroke occurred in-hospital in one coronary artery bypass graft patient unrelated to atrial fibrillation, and at 30 days in two additional patients, one in each group. There was no mortality. Conclusion. New-onset atrial fibrillation during 30 days of follow-up was rare after percutaneous coronary intervention but common after coronary artery bypass grafting. A prolonged uninterrupted heart rhythm monitoring strategy identified additional patients in both groups with new-onset atrial fibrillation after discharge.

Quantitative flow ratio versus fractional flow reserve for Heart Team decision-making in multivessel disease: the randomised, multicentre DECISION QFR trial.

BACKGROUND: Vessel-level physiological data derived from pressure wire measurements are one of the important determinant factors in the optimal revascularisation strategy for patients with multivessel disease (MVD). However, these may result in complications and a prolonged procedure time. AIMS: The feasibility of using the quantitative flow ratio (QFR), an angiography-derived fractional flow reserve (FFR), in Heart Team discussions to determine the optimal revascularisation strategy for patients with MVD was investigated. METHODS: Two Heart Teams were randomly assigned either QFR- or FFR-based data of the included patients. They then discussed the optimal revascularisation mode (percutaneous coronary intervention [PCI] or coronary artery bypass grafting [CABG]) for each patient and made treatment recommendations. The primary endpoint of the trial was the level of agreement between the treatment recommendations of both teams as assessed using Cohen's kappa. RESULTS: The trial included 248 patients with MVD from 10 study sites. Cohen's kappa in the recommended revascularisation modes between the QFR and FFR approaches was 0.73 [95% confidence interval {CI} : 0.62-0.83]. As for the revascularisation planning, agreements in the target vessels for PCI and CABG were substantial for both revascularisation modes (Cohen's kappa=0.72 [95% CI: 0.66-0.78] and 0.72 [95% CI: 0.66-0.78], respectively). The team assigned to the QFR approach provided consistent recommended revascularisation modes even after being made aware of the FFR data (Cohen's kappa=0.95 [95% CI:0.90-1.00]). CONCLUSIONS: QFR provided feasible physiological data in Heart Team discussions to determine the optimal revascularisation strategy for MVD. The QFR and FFR approaches agreed substantially in terms of treatment recommendations.

Predictors of late lumen enlargement after drug-coated balloon angioplasty for de novo coronary lesions.

BACKGROUND: Late lumen enlargement (LLE) - a positive remodelling phenomenon - after drug-coated balloon (DCB) angioplasty for stable coronary disease contributes to a lower restenosis rate. However, lesion characteristics promoting LLE remain unclear. AIMS: This study aimed to investigate predictive lesion characteristics for LLE using serial optical frequency domain imaging (OFDI) following DCB angioplasty for de novo coronary artery lesions. METHODS: This retrospective, single-centre observational study included patients with angina pectoris who underwent paclitaxel-coated balloon angioplasty without stenting under OFDI guidance as well as follow-up OFDI. OFDI endpoints were lumen volume, plaque phenotype, and procedure-associated dissection. LLE was defined as a ≥10% increase in the lumen volume of the treated lesion at follow-up. RESULTS: Between August 2016 and December 2019, among patients with successful DCB angioplasty, 108 lesions (83 patients) had available follow-up imaging after a median of 6.1 months. LLE was detected in 44 (40.7%) lesions. Fibrous/fibrocalcific and layered plaques had significantly larger lumen volumes at follow-up than immediately after the index procedure, whereas lipid plaques exhibited no significant difference. Medial dissection with an arc >90° revealed an increased lumen volume. Multivariate analysis showed that layered plaques (odds ratio [OR] 8.73, 95% confidence interval [CI]: 1.92-39.7; p=0.005) and medial dissection with an arc >90° (OR 4.65, 95% CI: 1.63-13.3; p=0.004) were independent LLE predictors. CONCLUSIONS: Layered plaques and extensive medial dissection after DCB angioplasty were associated with higher LLE occurrence in de novo coronary lesions. These findings may be clinically applicable to DCB therapeutic strategies based on plaque features.

Same-day discharge after percutaneous coronary procedures-Structured review and comprehensive meta-analysis.

INTRODUCTION: Percutaneous coronary intervention is a well-established revascularization strategy for patients with coronary artery disease. The safety and feasibility of performing these procedures on a same-day discharge basis for selected patients has been studied in a large number of mostly nonrandomized trials. An up to date literature review should focus on trials with radial access, representing the current standard for coronary procedures in Austria and other European countries. METHODS: The aim of this consensus statement is to review the most recent evidence for the safety and feasibility of performing same-day discharge procedures in selected patients. A structured literature search was performed using prespecified search criteria, focusing on trials with radial access procedures. RESULTS: A total of 44 clinical trials and 4 large meta-analyses were retrieved, spanning 21 years of clinical evidence from 2001 to 2022. The outcome data from a wide range of clinical settings were unanimous in showing no negative effect on early (24 h) or late (30 day) major adverse events after same-day discharge coronary procedures. Based on nine prospective trials a comprehensive meta-analysis was compiled. Using 1­month major adverse events data the pooled odds ratio of same-day discharge versus overnight stay procedures was 0.66 (95% confidence interval, CI 0.35-01.24; p = 0.19; I2 0%), indicating a noninferiority in carefully selected patients. CONCLUSION: Outcome data from same-day discharge coronary intervention trials with radial access confirm the robust safety profile showing no increase in the risk of major adverse events compared to overnight stay.

Same-day discharge after percutaneous coronary procedures-Consensus statement of the working group of interventional cardiology (AGIK) of the Austrian Society of Cardiology.

INTRODUCTION: Percutaneous coronary intervention is a well-established revascularization strategy for patients with coronary artery disease. Recent technical advances such as radial access, third generation drug-eluting stents and highly effective antiplatelet therapy have substantially improved the safety profile of coronary procedures. Despite several practice guidelines and a clear patient preference of early hospital discharge, the percentage of coronary procedures performed in an outpatient setting in Austria remains low, mostly due to safety concerns. METHODS: The aim of this consensus statement is to provide a practical framework for the safe and effective implementation of coronary outpatient clinics in Austria. Based on a structured literature review and an in-depth analysis of available practice guidelines a consensus statement was developed and peer-reviewed within the working group of interventional cardiology (AGIK) of the Austrian Society of Cardiology. RESULTS: Based on the available literature same-day discharge coronary procedures show a favorable safety profile with no increase in the risk of major adverse events compared to an overnight stay. This document provides a detailed consensus in various clinical settings. The most important prerequisite for same-day discharge is, however, adequate selection of suitable patients and a structured peri-interventional and postinterventional management plan. CONCLUSION: Based on the data analysis this consensus document provides detailed practice guidelines for the safe operation of daycare cathlab programs in Austria.

Comparison of angiographic change in side-branch ostium after drug-coated balloon vs. drug-eluting stent vs. medication for the treatment of de novo coronary bifurcation lesions.

OBJECTIVES: Data on side-branch (SB) ostial effect after drug-coated balloon (DCB) treatment in the context of de novo coronary bifurcation lesions are limited. We aimed to investigate the angiographic outcomes of SB ostium after DCB treatment compared with drug-eluting stents (DESs) implantation in the main vessel (MV) or optimal medical therapy (OMT) for the treatment of de novo coronary bifurcation lesions. METHODS: Serial angiographic changes in the SB ostium were compared between DCB, DES, and medication alone for MV treatment. Δ value was calculated by subtracting the follow-up value from the pre-procedure value. RESULTS: A total of 132 bifurcation lesions were included for analysis (44 lesions in DCB group; 38 lesions in DES group; 50 lesions in OMT group). The minimal lumen diameter (MLD) of SB ostium showed an increase at follow-up in the DCB group, whereas a decrease was observed in both the DES and OMT groups (ΔMLD: -0.16 ± 0.45 mm for DCB group vs. 0.50 ± 0.52 mm for DES group vs. 0.08 ± 0.38 mm for OMT group, p < 0.001). The diameter stenosis (DS) of SB ostium showed a marked decrease at follow-up in the DCB group, in contrast to an increase observed in both the DES and OMT groups (ΔDS: 8.01 ± 18.96% for DCB group vs. -18.68 ± 18.60% for DES group vs. -2.05 ± 14.58% for OMT group, p < 0.001). CONCLUSIONS: In de novo coronary bifurcation lesions, DCB treatment on the MV demonstrated favorable angiographic outcomes in the SB ostium at 6-9 month follow-up compared to DES implantation or OMT.

Use of coronary artery calcium score and coronary CT angiography to guide cardiovascular prevention and treatment.

Currently, cardiovascular risk stratification to guide preventive therapy relies on clinical scores based on cardiovascular risk factors. However, the discriminative power of these scores is relatively modest. The use of coronary artery calcium score (CACS) and coronary CT angiography (CCTA) has surfaced as methods for enhancing the estimation of risk and potentially providing insights for personalized treatment in individual patients. CACS improves overall cardiovascular risk prediction and may be used to improve the yield of statin therapy in primary prevention, and possibly identify patients with a favorable risk/benefit relationship for antiplatelet therapies. CCTA holds promise to guide anti-atherosclerotic therapies and to monitor individual response to these treatments by assessing individual plaque features, quantifying total plaque volume and composition, and assessing peri-coronary adipose tissue. In this review, we aim to summarize current evidence regarding the use of CACS and CCTA for guiding lipid-lowering and antiplatelet therapy and discuss the possibility of using plaque burden and plaque phenotyping to monitor response to anti-atherosclerotic therapies.

PCI vs. CABG in left main with multi-vessel coronary artery disease and diabetes: Case report.

This case challenges the conventional preference for coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI) in patients with diabetes, left main coronary artery disease (LMCAD) and multivessel disease. Current guidelines generally recommend CABG, especially in the context of LMCAD. However, our case involves a male patient with diabetes with LMCAD and extensive multivessel disease who was successfully treated with PCI, demonstrating a favorable outcome. Despite the high-risk profile, including a SYNTAX score of 28, the PCI approach was selected. This decision was supported by evidence suggesting comparable outcomes between PCI and CABG in similar patients. Our case highlights the potential of PCI as not just a viable, but potentially superior alternative in specific high-risk patients with diabetes, contrary to the prevailing belief in favor of CABG for all patients with left main involvement.

Jailed high-pressure balloon technique is superior to jailed wire technique in protecting side branch of coronary bifurcation lesions.

Objectives. This study investigated the influence of higher pressure protection with a small diameter balloon of side branch (SB) on bifurcation lesions. Background. Of the different coronary stent implantation techniques, the modified jailed balloon technique has become a viable option for bifurcation lesions. However, there was no detailed study on the relationship between the balloon inflation pressure of the main vessel (MV) and SB. Methods. In this study, we collected information of patients who underwent percutaneous coronary intervention (PCI) for bifurcated lesions between March 2019 and December 2022. They were divided into two groups according to the operation way: active jailed balloon technique (A-JBT) group and jailed wire technique (JWT) group. Results. A total of 216 patients were enrolled. The A-JBT group had a larger SB stenosis diameter (1.53 ± 0.69 vs. 0.95 ± 0.52, p < .001), the lower degree of stenosis (44.34 ± 18.30 vs. 63.69 ± 17.34, p < .001) compared to the JWT group. However, the JWT group had a higher incidence of SB occlusion (18.0% vs. 1.9%, p < .001) compared to the A-JBT group. Nevertheless, the success rate for both groups was 100%. Conclusions. This novel high inflation pressure and small diameter balloon approach we propose has significant advantages. There is a lower rate of SB occlusion and SB dissection, which is more cost-effective and provides better clinical outcomes for the patient. This method should be considered in the future for treating bifurcation lesions.

The association between the triglyceride-glucose index and in-stent restenosis in patients undergoing percutaneous coronary intervention: a systematic review and meta-analysis.

BACKGROUND: Insulin resistance (IR) can lead to cellular metabolic disorders, activation of oxidative stress, and endothelial dysfunction, contributing to in-stent restenosis (ISR). The triglyceride-glucose index (TyG index), a new indicator reflecting IR, is extensively researched in the cardiovascular field. This study, through a meta-analysis, aimed to utilize a larger combined sample size and thereby enhance the overall test efficacy to explore the TyG index-ISR relationship. METHODS: A thorough search was conducted in the PubMed, EMBASE, Web of Science, and Cochrane Library databases to find original papers and their references published between 1990 and January 2024. This search included both prospective and retrospective studies detailing the correlation between the TyG index and ISR in individuals with coronary heart disease (CHD). OUTCOMES: The five included articles comprised 3,912 participants, and the odds ratio (OR) extracted from each study was combined using the Inverse Variance method. Results showed that, in the context of CHD patients, each incremental unit in the TyG index, when treated as a continuous variable, corresponded to a 42% elevation in ISR risk (95% CI 1.26-1.59, I²=13%, p < 0.005). When analyzing the TyG index categorically, the results revealed a higher ISR risk in the highest TyG index group compared to the lowest group (OR: 1.69, 95% CI 1.32-2.17, I²=0). Additionally, in patients with chronic coronary syndrome (CCS), each unit increase in the TyG index, the risk of ISR in patients increased by 37% (95% CI 1.19-1.57, I²=0%, p < 0.005). This correlation was also observable in acute coronary syndrome (ACS) patients (OR:1.48, 95% CI 1.19-1.85, I²=0, p < 0.005). CONCLUSIONS: The TyG index, an economical and precise surrogate for IR, is significantly linked with ISR. Furthermore, this correlation is unaffected by the type of coronary heart disease.

Analysis of core outcome set reporting in coronary intervention trials.

BACKGROUND: This paper will focus on outcome reporting within percutaneous coronary intervention (PCI) trials. A core outcome set (COS) is a standardised set of outcomes that are recommended to be reported in every clinical trial. Using a COS can help to ensure that all relevant outcomes are consistently reported across clinical trials. In 2018, the European Society of Cardiology outlined the only COS published for PCI trials. METHODS: We searched the literature for all randomised controlled trials published between 2014 and 2022. PCI trials included were late-phase trials and must investigate coronary intervention. The primary outcome was the proportion of trials that reported all of the COS-defined outcomes within their publication as either a primary, secondary or safety endpoint. The secondary outcomes included; the number of primary outcomes reported per study, the proportion of studies which use patient and public involvement (PPI) during trial design, outcome variability and outcome consistency. RESULTS: 9580 trials were screened and 115 studies met inclusion/exclusion criteria. Our study demonstrated that 55% (34/62) of PCI trials used a COS when it was available, compared with 40% (21/53) before the availability of a PCI COS set, p=0.121. Fewer primary outcomes were reported after the implementation of the COS, 2 compared with 2.3, p=0.014. There was no difference in the use of PPI between either group. There was a higher level of variability in outcomes reported before the availability of the COS, while the consistency of outcome reporting remained similar. CONCLUSION: The use of a COS in PCI trials is low. This study provides evidence that there still is a lack of awareness of the COS among those who design clinical trials. We also presented the inconsistency and heterogenicity in reporting clinical trial outcomes. Finally, there was a clear lack of PPI utilisation in PCI trials.

Association of Age- and Body Mass Index-Stratified High On-Treatment Platelet Reactivity With Coronary Intervention Outcomes in East Asian Patients.

BACKGROUND: Although age and body mass index (BMI) significantly affect platelet reactivity units and clinical outcomes after percutaneous coronary intervention, there are limited data on the relationship between high on-treatment platelet reactivity (HPR) and clinical outcomes on age and BMI differences. Thus, we investigated the association of HPR with clinical outcomes according to age and BMI. METHODS AND RESULTS: The study analyzed 11 714 patients who underwent platelet function tests after percutaneous coronary intervention. The primary end point was the occurrence of major adverse cardiac and cerebrovascular events (MACCEs), whereas the secondary end point was major bleeding. HPR was defined as platelet reactivity units ≥252. Patients were categorized by age (<67 years of age or ≥67 years of age) and BMI (≤22.6 kg/m2 or >22.6 kg/m2). Patients <67 years of age with HPR had increases in both MACCEs (adjusted hazard ratio [HR], 1.436 [95% CI, 1.106-1.867]; P=0.007) and major bleeding (adjusted HR, 1.584 [95% CI, 1.095-2.290]; P=0.015) compared with the those with non-HPR, respectively. In patients ≥67 years of age with HPR, there were no differences in MACCEs, but there was a decrease in major bleeding (adjusted HR, 0.721 [95% CI, 0.542-0.959]; P=0.024). Meanwhile, patients with HPR with BMI >22.6 kg/m2 had increases in MACCEs (adjusted HR, 1.387 [95% CI, 1.140-1.688]; P=0.001). No differences were shown in major bleeding. CONCLUSIONS: HPR was linked to an increase in MACCEs or a decrease in major bleeding in patients after percutaneous coronary intervention, depending on age and BMI. This study is the first to observe that clinical outcomes in patients with HPR after percutaneous coronary intervention may vary based on age and BMI. Because the study is observational, the results should be viewed as hypothesis generating and emphasize the need for randomized clinical trials.

Aetiology and predictors of major bleeding events in patients with heart failure with reduced ejection fraction undergoing percutaneous coronary intervention.

OBJECTIVES: We sought to determine the relationship between the degree of left ventricular ejection fraction (LVEF) impairment and the frequency and type of bleeding events after percutaneous coronary intervention (PCI). DESIGN: This was an observational retrospective cohort analysis. Patients who underwent PCI from 2009 to 2017 were identified from our institutional National Cardiovascular Disease Registry (NCDR) CathPCI database. Patients were stratified by pre-PCI LVEF: preserved (≥50%), mildly reduced (41%-49%) and reduced (≤40%) LVEF. PRIMARY OUTCOME MEASURES: The outcome was major bleeding, defined by NCDR criteria. Events were classified based on bleeding aetiology and analysed by multivariable logistic regression. RESULTS: Among 13 537 PCIs, there were 817 bleeding events (6%). The rate of bleeding due to any cause, blood transfusion, gastrointestinal bleeding and coronary artery perforation or tamponade each increased in a stepwise fashion comparing preserved, mildly reduced and reduced LVEF reduction (p<0.05 for all comparisons). However, there were no differences in bleeding due to asymptomatic drops in haemoglobin, access site haematoma or retroperitoneal bleeding. After multivariable adjustment, mildly reduced and reduced LVEF remained independent predictors of bleeding events (OR 1.36, 95% CI 1.06 to 1.74, p<0.05 and OR 1.73, 95% CI 1.45 to 2.06, p<0.0001). CONCLUSIONS: The degree of LV dysfunction is an independent predictor of post-PCI major bleeding events. Patients with mildly reduced or reduced LVEF are at greatest risk of post-PCI bleeding, driven by an increased need for blood transfusion, major GI bleeding events and coronary artery perforation or tamponade. Pre-PCI LV dysfunction does not predict asymptomatic declines in haemoglobin, access site haematoma or retroperitoneal bleeding.

Prevalence and anatomical factors associated with stent under-expansion in non-severely calcified lesions.

BACKGROUND: Stent underexpansion, typically related to lesion calcification, is the strongest predictor of adverse events after percutaneous coronary intervention (PCI). Although uncommon, underexpansion may also occur in non-severely calcified lesions. AIM: We sought to identify the prevalence and anatomical characteristics of underexpansion in non-severely calcified lesions. METHODS: We included 993 patients who underwent optical coherence tomography-guided PCI of 1051 de novo lesions with maximum calcium arc <180°. Negative remodeling (NR) was the smallest lesion site external elastic lamina diameter that was also smaller than the distal reference. Stent expansion was evaluated using a linear regression model accounting for vessel tapering; underexpansion required both stent expansion <70% and stent area <4.5mm2. RESULTS: Underexpansion was observed in 3.6% of non-heavily calcified lesions (38/1051). Pre-stent maximum calcium arc and thickness were greater in lesions with versus without underexpansion (median 119° vs. 85°, p = 0.002; median 0.95 mm vs. 0.78 mm, p = 0.008). NR was also more common in lesions with underexpansion (44.7% vs. 24.5%, p = 0.007). In the multivariable logistic regression model, larger and thicker eccentric calcium, mid left anterior descending artery (LAD) location, and NR were associated with underexpansion in non-severely calcified lesions. The rate of underexpansion was especially high (30.7%) in lesions exhibiting all three morphologies. Two-year TLF tended to be higher in underexpanded versus non-underexpanded stents (9.7% vs. 3.7%, unadjusted hazard ratio [95% confidence interval] = 3.02 [0.92, 9.58], p = 0.06). CONCLUSION: Although underexpansion in the absence of severe calcium (<180°) is uncommon, mid-LAD lesions with NR and large and thick eccentric calcium were associated with underexpansion.

FFR-Guided Complete or Culprit-Only PCI in Patients with Myocardial Infarction.

BACKGROUND: The benefit of fractional flow reserve (FFR)-guided complete revascularization in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease remains unclear. METHODS: In this multinational, registry-based, randomized trial, we assigned patients with STEMI or very-high-risk non-STEMI (NSTEMI) and multivessel disease who were undergoing primary percutaneous coronary intervention (PCI) of the culprit lesion to receive either FFR-guided complete revascularization of nonculprit lesions or no further revascularization. The primary outcome was a composite of death from any cause, myocardial infarction, or unplanned revascularization. The two key secondary outcomes were a composite of death from any cause or myocardial infarction and unplanned revascularization. RESULTS: A total of 1542 patients underwent randomization, with 764 assigned to receive FFR-guided complete revascularization and 778 assigned to receive culprit-lesion-only PCI. At a median follow-up of 4.8 years (interquartile range, 4.3 to 5.2), a primary-outcome event had occurred in 145 patients (19.0%) in the complete-revascularization group and in 159 patients (20.4%) in the culprit-lesion-only group (hazard ratio, 0.93; 95% confidence interval [CI], 0.74 to 1.17; P = 0.53). With respect to the secondary outcomes, no apparent between-group differences were observed in the composite of death from any cause or myocardial infarction (hazard ratio, 1.12; 95% CI, 0.87 to 1.44) or unplanned revascularization (hazard ratio, 0.76; 95% CI, 0.56 to 1.04). There were no apparent between-group differences in safety outcomes. CONCLUSIONS: Among patients with STEMI or very-high-risk NSTEMI and multivessel coronary artery disease, FFR-guided complete revascularization was not shown to result in a lower risk of a composite of death from any cause, myocardial infarction, or unplanned revascularization than culprit-lesion-only PCI at 4.8 years. (Funded by the Swedish Research Council and others; FULL REVASC ClinicalTrials.gov number, NCT02862119.).

Coronary sinus reducer for the treatment of refractory angina (ORBITA-COSMIC): a randomised, placebo-controlled trial.

BACKGROUND: The coronary sinus reducer (CSR) is proposed to reduce angina in patients with stable coronary artery disease by improving myocardial perfusion. We aimed to measure its efficacy, compared with placebo, on myocardial ischaemia reduction and symptom improvement. METHODS: ORBITA-COSMIC was a double-blind, randomised, placebo-controlled trial conducted at six UK hospitals. Patients aged 18 years or older with angina, stable coronary artery disease, ischaemia, and no further options for treatment were eligible. All patients completed a quantitative adenosine-stress perfusion cardiac magnetic resonance scan, symptom and quality-of-life questionnaires, and a treadmill exercise test before entering a 2-week symptom assessment phase, in which patients reported their angina symptoms using a smartphone application (ORBITA-app). Patients were randomly assigned (1:1) to receive either CSR or placebo. Both participants and investigators were masked to study assignment. After the CSR implantation or placebo procedure, patients entered a 6-month blinded follow-up phase in which they reported their daily symptoms in the ORBITA-app. At 6 months, all assessments were repeated. The primary outcome was myocardial blood flow in segments designated ischaemic at enrolment during the adenosine-stress perfusion cardiac magnetic resonance scan. The primary symptom outcome was the number of daily angina episodes. Analysis was done by intention-to-treat and followed Bayesian methodology. The study is registered with ClinicalTrials.gov, NCT04892537, and completed. FINDINGS: Between May 26, 2021, and June 28, 2023, 61 patients were enrolled, of whom 51 (44 [86%] male; seven [14%] female) were randomly assigned to either the CSR group (n=25) or the placebo group (n=26). Of these, 50 patients were included in the intention-to-treat analysis (24 in the CSR group and 26 in the placebo group). 454 (57%) of 800 imaged cardiac segments were ischaemic at enrolment, with a median stress myocardial blood flow of 1·08 mL/min per g (IQR 0·77-1·41). Myocardial blood flow in ischaemic segments did not improve with CSR compared with placebo (difference 0·06 mL/min per g [95% CrI -0·09 to 0·20]; Pr(Benefit)=78·8%). The number of daily angina episodes was reduced with CSR compared with placebo (OR 1·40 [95% CrI 1·08 to 1·83]; Pr(Benefit)=99·4%). There were two CSR embolisation events in the CSR group, and no acute coronary syndrome events or deaths in either group. INTERPRETATION: ORBITA-COSMIC found no evidence that the CSR improved transmural myocardial perfusion, but the CSR did improve angina compared with placebo. These findings provide evidence for the use of CSR as a further antianginal option for patients with stable coronary artery disease. FUNDING: Medical Research Council, Imperial College Healthcare Charity, National Institute for Health and Care Research Imperial Biomedical Research Centre, St Mary's Coronary Flow Trust, British Heart Foundation.