Background Myocardial Infarction with No Obstructive Coronary Arteries (MINOCA) or Nonischemic Myocardial Injury affects approximately 1 in 9 patients presenting with acute coronary syndrome, yet evidence-based therapies are lacking. Coronary microvascular dysfunction is implicated in the pathogenesis of suspected MINOCA, but its prevalence, prognostic implications and treatment are uncertain.The objectives are, first, to assess the prevalence of coronary microvascular dysfunction in patients with suspected MINOCA and, second, to implement endotype-informed stratified medicine involving patients with coronary microvascular dysfunction to treatment with eplerenone, a cardio- and vasculo-protective mineralocorticoid receptor antagonist. Methods This is a prospective, registry-based, multicenter, diagnostic study and nested, randomized, controlled, open-label, blinded-endpoint (PROBE) basket trial. Up to 400 patients with clinically suspected MINOCA and one or more cardiovascular risk factors will be enrolled into a registry-based diagnostic study. Coronary microvascular function will be assessed during invasive angiography using thermodilution. Patients with an index of coronary microvascular resistance (IMR) ≥ 25 will be randomized 1:1 to eplerenone (25-50 mg daily for 6 months) or standard care without eplerenone (control group) (n = 150 randomized). Final endotypes will be centrally adjudicated by a panel of blinded cardiologists.The primary outcome of the diagnostic study is the proportion of patients with IMR ≥ 25 during index coronary angiography. Secondary outcomes include coronary flow reserve, cardiovascular MRI parameters, patient-reported outcome measures, biomarkers of myocardial fibrosis and vascular inflammation, health outcomes and health economic assessments.The primary outcome of the randomized trial is the within-individual change in NT-proBNP at baseline, 1 month, and 6 months, based on intention-to-treat. Secondary outcomes include mechanistic blood biomarkers and patient-reported outcome measures. Value This registry-based randomized trial will provide novel evidence on endotype-informed secondary prevention therapy with eplerenone for suspected MINOCA.

Background Patients with angina and no obstructive coronary artery disease (ANOCA) frequently receive empirical antianginal therapy that fails to target underlying pathophysiological mechanisms. Whether stress perfusion cardiac magnetic resonance (CMR)-guided endotyping and stratified medical therapy improves treatment satisfaction and appropriate medication prescribing in this population is uncertain. Methods In the Coronary Microvascular Angina CMR Imaging Trial, 250 patients with suspected ANOCA, who had undergone invasive coronary angiography demonstrating no obstructive disease, were enrolled and underwent stress perfusion CMR with quantification of myocardial blood flow. Participants were randomised 1:1 to CMR-guided management (intervention) or angiography-guided management (control). Treatment satisfaction was assessed using the validated Treatment Satisfaction Questionnaire for Medication (TSQM-9) at baseline, 6 months and 12 months. Medication prescriptions were documented at these time points. Results Stress CMR imaging led to diagnostic reclassification in 53.0% of patients, with microvascular angina diagnosed in 51.0%. At 12 months, global treatment satisfaction was significantly higher in the intervention group compared with controls (adjusted difference, 19.30 units (95% CI 13.89 to 24.71); p<0.001), with consistent improvements across the effectiveness and convenience domains. CMR-guided management was associated with more appropriate prescribing, including higher use of preventive therapies (85.5% vs 67.5%; p=0.001), and more targeted antianginal prescribing, including calcium channel blockers (43.5% vs 27.0%; p=0.008) and long-acting nitrates (56.5% vs 32.5%; p<0.001). Conclusions In patients with ANOCA, non-invasive CMR-guided endotyping substantially improves treatment satisfaction and enables more appropriate, mechanism-targeted pharmacotherapy compared with angiography-guided care. Trial registration number ClinicalTrials.gov ID NCT04805814 .

Background Angina is a debilitating condition caused by coronary artery disease and microvascular dysfunction. Following coronary angiography angina and no obstructive coronary arteries is a common outcome, and women are disproportionately affected. The objectives are first, to assess causes of angina in patients undergoing invasive management; and second, to assess effects of coronary function test-guided management on clinical outcomes. Methods This is an international, multicenter, prospective, registry-based study and nested, randomized, controlled, triple-blind, and endpoint trial. Participants, community care providers, and outcomes assessors are masked. Consented participants enter the registry. Participants without obstructive coronary artery disease (luminal stenosis <50%, or fractional flow reserve >0.80) are eligible for randomization. Index of microcirculatory resistance (IMR; abnormal ≥25) and coronary flow reserve (CFR; abnormal <2.0; gray zone 2.0-2.5) are measured by bolus thermodilution, and results are disclosed (intervention) or not (control group) to the attending cardiologist. Results The primary outcome of the registry is the Seattle Angina Questionnaire summary score at baseline described by coronary artery disease status. Secondary outcomes include the prevalence of obstructive coronary artery disease, patient reported outcome measures and clinical outcomes. The primary outcome of the randomized trial is the within-individual change in Seattle Angina Questionnaire summary score at 12-months from baseline. Secondary outcomes include safety, diagnostic accuracy, patient reported outcome measures for quality of life, physical and psychological function, cardiovascular risk, clinical outcomes, health economics and mechanistic biomarkers. The first patient was screened on December 18, 2020 and the last patient was enrolled on June 30, 2026. Forty sites were included in the United Kingdom (n = 35), Republic of Ireland (n = 2), Holland (n = 2), and Poland (n = 1). In total, 1,483 participants were enrolled into the registry of whom 1,047 were randomized and 386 were not randomized (registry-only). Conclusion This international, registry-based clinical trial will provide novel evidence on the natural history of angina and stratified therapy for angina with no obstructive coronary arteries. Clinical trial registration https://clinicaltrials.gov/study/NCT04674449. Unique identifier NCT04674449

Coronary stent loss is a rare but potentially catastrophic complication of percutaneous coronary intervention (PCI), particularly during complex procedures involving calcified lesions and bifurcations. We report the case of a 74-year-old man undergoing PCI of a subacutely occluded proximal left anterior descending artery, complicated by stent dislodgement following an involuntary deep inspiration by the patient. The stent became partially detached from the delivery balloon and was successfully moved into the radial artery while remaining over the guidewire. A stepwise bailout strategy allowed safe completion of the coronary intervention via secondary access, followed by successful snaring and retrieval of the lost stent. This case highlights the importance of maintaining wire position, procedural patience, and structured problem-solving in managing rare but high-risk intraprocedural complications.

AIMS:The recently proposed Canadian Cardiovascular Society (CCS) classification categorizes post-infarction tissue injury into four stages, potentially improving risk stratification and guiding cardioprotective strategies. Its clinical and prognostic relevance in ST-elevation myocardial infarction (STEMI) remains unclear. We aimed to compare clinical characteristics across CCS stages and validate their prognostic implications in STEMI. METHODS AND RESULTS:We analysed 1109 STEMI patients included in three prospective studies. Cardiac magnetic resonance (CMR) imaging was performed 3 (interquartile range 2-5) days after myocardial infarction (MI) and patients were classified as follows: Stage 1 (aborted MI), Stage 2 (MI with necrosis and absence of microvascular injury), Stage 3 (MI with necrosis and microvascular obstruction), and Stage 4 (MI with necrosis and intramyocardial haemorrhage). This analysis revealed distinct patterns of clinical presentation, biomarker profiles, and cardiac function across the different CCS stages. There were differences in adverse clinical event rates and mortality between CCS stages [major adverse cardiovascular event (MACE): 0.7%, 3.4%, 3.1%, and 15.7%, P < 0.001 and mortality: 0.7%, 1.7%, 0.9%, and 6.3%, P < 0.001]. The CCS stage had a moderate to good predictive value for MACE and mortality [area under the curve (AUC) 0.74 (95% CI: 0.68-0.80), P < 0.001 and AUC 0.71 (95% CI: 0.61-0.80), P < 0.001] at 12 months, respectively. CCS stages were independently associated with MACE in multivariable Cox regression [hazard ratio: 2.18 (95% CI: 1.70-2.78), P < 0.001]. CONCLUSION:This study describes clinical characteristics across CCS stages and provides insights into their prognostic implications in a large cohort of STEMI patients reperfused by percutaneous coronary intervention. These data should inform the use of CCS stages in future trial designs.

AIMS:Patients with angina and no obstructive coronary artery disease (ANOCA) experience persistent symptoms, adverse illness perceptions, and psychological distress, often driven by diagnostic uncertainty. We evaluated whether non-invasive stress perfusion cardiovascular magnetic resonance (CMR), used to define ischaemic endotypes and guide targeted therapy, improves illness perception and psychological health compared with standard angiography-guided care. METHODS AND RESULTS:The Coronary microvascular angina Cardiac Magnetic Resonance imaging (CorCMR) trial was a prospective, multicentre, randomized controlled superiority trial. Patients with chest pain undergoing invasive coronary angiography showing no obstructive coronary artery disease were randomized 1:1 to CMR-guided endotype-specific management (intervention) or standard angiography-guided care (control). Illness perception was assessed using the Brief Illness Perception Questionnaire (BIPQ). Psychological health was assessed using the Patient Health Questionnaire-4 (PHQ-4). Assessments occurred at baseline, 6 months, and 12 months. A total of 250 participants were randomized (126 control, 124 intervention; mean age 63.3 years, 50.4% female). At 6 months, BIPQ scores were significantly lower in the intervention vs. control group [adjusted mean difference -8.67 (95% CI -12.04, -5.30); P < 0.001], with sustained benefit at 12 months [adjusted mean difference -10.80 (95% CI -14.27, -7.33); P < 0.001]. PHQ-4 scores were also significantly reduced at 6 months [adjusted mean difference -0.88 (95% CI -1.19, -0.57); P < 0.001] and 12 months [adjusted mean difference -0.97 (95% CI -1.29, -0.65); P < 0.001]. CONCLUSION:In patients with ANOCA, non-invasive CMR-guided endotyping linked to targeted therapy resulted in substantial and sustained improvements in illness perception and psychological health, highlighting the importance of diagnostic clarification in addressing the psychological burden of this condition.

Following the recently upgraded recommendations for intravascular imaging use from the European Society of Cardiology and the American Heart Association, we present a UK consensus statement on the use of intravascular ultrasound (IVUS) in percutaneous coronary intervention. Developed by 26 senior interventional cardiologists across a range of UK centres, this statement reflects growing evidence and changing expectations for IVUS use. We discuss the indications for IVUS, the current patterns of use in the UK, anticipated future standards and the need for broader adoption. We propose a standardised workflow and recommend routine documentation of a core IVUS dataset to support quality and as a mechanism for improvement. Persistent barriers, such as perceived cost, training variability and procedural integration, are addressed with practical solutions, including the introduction of national training curricula incorporating intravascular imaging accreditation for operators and targeted education for allied health professionals. Our goal is to support clinicians, catheter lab teams and service leads in embedding IVUS more consistently into practice to optimise patient outcomes.

Patients undergoing invasive coronary angiography for the investigation of chest pain commonly do not have obstructive coronary artery disease. In contemporary practice, most of these individuals do not undergo functional diagnostic tests, leaving the cause of the chest pain uncertain. Stress cardiovascular magnetic resonance imaging (MRI) can be used to measure myocardial blood flow, detect coronary microvascular dysfunction and endotype individual patients, but evidence of clinical utility from randomized trials is lacking. This study was a prospective, multicenter, parallel group, 1:1 randomized, controlled superiority trial of adenosine stress cardiovascular MRI-guided management in 250 patients (mean age, 63.3 years; 50.4% female) with chest pain and unobstructed coronary arteries. The primary outcome of the diagnostic study, defined as the reclassification of the initial diagnosis based on the angiogram, occurred in 131 patients (53.0% (95% confidence interval: 46.6−59.3%); P < 0.001), indicating that the primary outcome for the diagnostic study was met. The primary outcome of the randomized trial was the Seattle Angina Questionnaire (SAQ) summary score at 12 months after randomization. The mean ± s.d. SAQ summary scores at 12 months in the intervention and control groups were 70.9 ± 23.6 (21.7 ± 22.6 change from baseline) and 52.1 ± 24.1 (−0.8 ± 20.4 change from baseline) (adjusted mean difference: 20.9 (95% confidence interval: 15.8–26.0)), respectively, indicating that the primary outcome of the randomized trial was met. Improvements were also observed in the prespecified secondary outcome of the EQ-5D-5L questionnaire at 12 months (adjusted mean difference 0.09 (95% confidence interval: 0.04−0.13)). In this study of patients with chest pain and unobstructed coronary arteries, endotyping-informed therapy revised the diagnosis in more than half of the participants and improved angina and health-related quality of life. ClinicalTrials.gov identifier: NCT04805814 .

BACKGROUND:Intravenous adenosine induces stable myocardial hyperemia for coronary microvascular function testing. Iodinated radiographic contrast media induce transient, submaximal hyperemia. We assessed the feasibility, diagnostic value, and potential cost-effectiveness of contrast-derived indices of microvascular function. METHODS:Coronary flow reserve, index of microvascular resistance, and microvascular resistance reserve were assessed using a diagnostic guidewire. Intracoronary bolus thermodilution injections were performed at rest, immediately after an 8-mL bolus of iohexol, repeated after a second 8-mL bolus, and during intravenous adenosine infusion. Receiver operating characteristic analyses assessed the discriminatory ability of the contrast-derived indices (contrast-derived coronary flow reserve, contrast-derived index of microcirculatory resistance, contrast-derived microvascular resistance reserve) to detect abnormal adenosine-derived indices (coronary flow reserve <2.0, index of microvascular resistance ≥25, and microvascular resistance reserve <2.1). RESULTS:Among 106 coronary arteries from 93 patients (median age 63 years; 62% women; 13% with diabetes), 88% of assessments were undertaken in the left anterior descending artery. Median fractional flow reserve was 0.88 (interquartile range, 0.85-0.92). Contrast-derived coronary flow reserve <2.0 (area under the curve 0.81; sensitivity 67%, specificity 80%, positive predictive value 40%, negative predictive value 92%), contrast-derived index of microcirculatory resistance >47 (area under the curve 0.82; 80%, 79%, 60%, 91%), and contrast-derived microvascular resistance reserve <1.9 (area under the curve 0.82; 67%, 89%, 35%, 97%) were best for predicting their adenosine-derived counterpart indices. There was good correlation on repeatability testing from the second contrast bolus. A hybrid approach reduced adenosine use by 40%, saving $30 800 (USA) or £8000 (UK) per 1000 vessels assessed. CONCLUSIONS:Contrast-derived indices have high specificity and negative predictive value, enabling rapid exclusion of microvascular dysfunction. This method is feasible, clinically useful and cost-saving compared with routine adenosine testing. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT04674449.

Background The relationship between atherosclerosis and endotypes of myocardial ischaemia with no obstructive coronary artery disease (INOCA) is unclear. We investigated potential associations between cumulative atherosclerotic plaque burden quantified using the Gensini score, novel invasive indices of coronary microvascular function (microvascular resistance reserve (MRR); resistive reserve ratio (RRR)) and related INOCA endotypes.Methods Coronary angiography and invasive coronary function tests were simultaneously acquired in the CorMicA cohort. A comprehensive physiological assessment was performed using both a thermodilution-based diagnostic guidewire and intracoronary acetylcholine provocation testing. Angiograms were examined for luminal stenosis in each segment of the SYNTAX coronary model. Cumulative plaque burden was quantified using the Gensini score, which incorporated both the number of diseased coronary segments and stenosis severity. Results were compared with indices of microvascular function and INOCA endotypes. Angiographic analyses were performed blind to coronary physiology findings.Results In 151 participants (median age 61 years; 73.5% female) without flow-limiting coronary artery disease, medical history included 41.7% smoking, 63.6% hypertension and 19.2% diabetes mellitus. The left anterior descending artery underwent diagnostic guidewire testing in 85.4%, and 55.0% of participants had abnormal coronary flow reserve (CFR) and/or Index of Microcirculatory Resistance (IMR). The median Gensini score was 6.0 (IQR 2.5-11.0). CFR (p=0.012), MRR (p=0.026) and RRR (p=0.026), but not IMR (p=0.445), were univariably associated with raised Gensini scores. These significant effects persisted in multivariable models controlling for potential confounders. Considering INOCA endotypes, Gensini scores differed among participants with microvascular angina (MVA) (7.0 (2.5-11.0)), vasospastic angina (VSA) (4.5 (2.0-10.0)), mixed MVA/VSA (9.0 (5.0-11.5)) and non-cardiac symptoms (3.5 (1.5-8.0)); Kruskal-Wallis p=0.030.Conclusions Reduced CFR, MRR and RRR, and MVA were associated with increased coronary atherosclerotic plaque burden, as evidenced by higher Gensini scores. These novel findings provide a mechanistic link between INOCA and cardiovascular events, reinforcing the importance of antiatherosclerosis therapy in patients with MVA.

Abstract Background The recently proposed Canadian Cardiovascular Society (CCS) classification of acute myocardial infarction (MI) describes 4 stages of tissue injury identified by cardiac magnetic resonance imaging (CMR); 1) oedema without late gadolinium enhancement (LGE); 2) LGE without microvascular obstruction (MVO); 3) MVO; and 4) intramyocardial haemorrhage (IMH). Prior studies examining the relationship between these characteristics and outcomes are limited by variations in imaging and measurement techniques, in particular the distinction between MVO and IMH. The relationship between the proposed CCS classification of MI and outcomes has not been described. Purpose To explore the prognostic significance of the CCS classification of MI tissue injury in patients with ST-elevation MI (STEMI). Methods The British Heart Foundation MR-MI study was a prospective single-centre CMR cohort study in patients with STEMI (July 2011-November 2012). CMR was performed on a single Siemens MAGNETOM Avanto 1.5-Tesla scanner at 2 days post-STEMI. The imaging protocol included LGE and T2* mapping, allowing for the identification of infarct, MVO, and IMH. Follow-up for the occurance of major adverse cardiovascular events (MACE) (recurrent MI, ischaemic stroke and cardiovascular death) and a composite outcome of heart failure hospitalization/ICD implantation (HFH) or all-cause death was performed via electronic case note review. Results 246 patients had complete data for this analysis. Of these, 6 (2%) were CCS Stage 1, 105 (43%) were Stage 2, 33 (13%) were Stage 3, and 102 (41%) were Stage 4. Due to the low number in CCS stage 1, these patients were pooled with Stage 2 for the purposes of this analysis (CCS Stage 1/2). Average age was 58 (SD 11) years and 188 (76%) were male. With higher CCS stage, more patients were Killip class III/IV at presentation, had the LAD as culprit artery and had TIMI flow 0/1 pre-PCI. Patients with higher CCS stage had higher peak troponin-I and NT-proBNP, lower left ventricular function, higher left ventricular volumes and larger infarct size (Table). Median follow-up was 11.8 years. HFH or all-cause death occurred in 80 (33%) patients (22 HFH and 58 all-cause deaths), and MACE occurred in 63 (26%) patients (41 recurrent MI, 11 ischaemic stroke events, and 11 cardiovascular deaths). There were no significant differences in outcomes between CCS Stage 3 and CCS Stage 1/2 (Figure). Patients with CCS Stage 4 had a higher risk of HFH or all-cause death (HR 1.73, 95%CI 1.08-2.77; p=0.022) and MACE (HR 1.88, 95%CI 1.10-3.20; p=0.021) as compared with those in CCS Stage 1/2 (Figure). Conclusion The novel CCS classification of MI tissue injury identifies patients at the highest risk of adverse outcomes following STEMI. The relationship between the presence of IMH (CCS Stage 4) and adverse outcomes highlights the importance of T2* imaging in post-MI CMR protocols in order to identify this prognostically important biomarker.

BACKGROUND:The prognostic significance of various microvascular injury (MVI) patterns after ST-segment elevation myocardial infarction (STEMI) is not well known. OBJECTIVES:This study sought to investigate the prognostic implications of different MVI patterns in STEMI patients. METHODS:The authors analyzed 1,109 STEMI patients included in 3 prospective studies. Cardiac magnetic resonance (CMR) was performed 3 days (Q1-Q3: 2-5 days) after percutaneous coronary intervention (PCI) and included late gadolinium enhancement imaging for microvascular obstruction (MVO) and T2∗ mapping for intramyocardial hemorrhage (IMH). Patients were categorized into those without MVI (MVO-/IMH-), those with MVO but no IMH (MVO+/IMH-), and those with IMH (IMH+). RESULTS:MVI occurred in 633 (57%) patients, of whom 274 (25%) had an MVO+/IMH- pattern and 359 (32%) had an IMH+ pattern. Infarct size was larger and ejection fraction lower in IMH+ than in MVO+/IMH- and MVO-/IMH- (infarct size: 27% vs 19% vs 18% [P < 0.001]; ejection fraction: 45% vs 50% vs 54% [P < 0.001]). During a median follow-up of 12 months (Q1-Q3: 12-35 months), a clinical outcome event occurred more frequently in IMH+ than in MVO+/IMH- and MVO-/IMH- subgroups (19.5% vs 3.6% vs 4.4%; P < 0.001). IMH+ was the sole independent MVI parameter predicting major adverse cardiovascular events (HR: 3.88; 95% CI: 1.93-7.80; P < 0.001). CONCLUSIONS:MVI is associated with future adverse outcomes only in patients with a hemorrhagic phenotype (IMH+). Patients with only MVO (MVO+/IMH-) had a prognosis similar to patients without MVI (MVO-/IMH-). This highlights the independent prognostic importance of IMH in assessing and managing risk after STEMI.

Background The associations between deprivation and illness trajectory after hospitalisation for coronavirus disease-19 (COVID-19) are uncertain. Methods A prospective, multicentre cohort study was conducted on post-COVID-19 patients, enrolled either in-hospital or shortly post-discharge. Two evaluations were carried out: an initial assessment and a follow-up at 28–60 days post-discharge. The study encompassed research blood tests, patient-reported outcome measures, and multisystem imaging (including chest computed tomography (CT) with pulmonary and coronary angiography, cardiovascular and renal magnetic resonance imaging). Primary and secondary outcomes were analysed in relation to socioeconomic status, using the Scottish Index of Multiple Deprivation (SIMD). The EQ-5D-5L, Brief Illness Perception Questionnaire (BIPQ), Patient Health Questionnaire-4 (PHQ-4) for Anxiety and Depression, and the Duke Activity Status Index (DASI) were used to assess health status. Results Of the 252 enrolled patients (mean age 55.0 ± 12.0 years; 40% female; 23% with diabetes), deprivation status was linked with increased BMI and diabetes prevalence. 186 (74%) returned for the follow-up. Within this group, findings indicated associations between deprivation and lung abnormalities ( p = 0.0085), coronary artery disease ( p = 0.0128), and renal inflammation ( p = 0.0421). Furthermore, patients with higher deprivation exhibited worse scores in health-related quality of life (EQ-5D-5L, p = 0.0084), illness perception (BIPQ, p = 0.0004), anxiety and depression levels (PHQ-4, p = 0.0038), and diminished physical activity (DASI, p = 0.002). At the 3-month mark, those with greater deprivation showed a higher frequency of referrals to secondary care due to ongoing COVID-19 symptoms ( p = 0.0438). However, clinical outcomes were not influenced by deprivation. Conclusions In a post-hospital COVID-19 population, socioeconomic deprivation was associated with impaired health status and secondary care episodes. Deprivation influences illness trajectory after COVID-19.

Introduction We aimed to understand the impact of being a healthcare worker on the progression and outcomes of illness in individuals hospitalised because of post-COVID-19 complications. Materials and Methods The CISCO-19 study included patients hospitalised with COVID-19 and assessed baseline characteristics at index and multi-system phenotyping 28–60 days following discharge from hospital. Our analysis sought to compare the health and recovery metrics of healthcare workers within this cohort against those of non-healthcare professionals, considering variables like age, gender, cardiovascular risk, and severity of inflammation. Results A total of 168 patients, 28–60 days post their last hospital care, were assessed. Among them, 36 identified as healthcare workers. Comparatively, healthcare workers were found to be predominantly of a similar age to non-healthcare workers but had a higher proportion of females. In adjusted multivariate logistic regression analysis, healthcare worker status associated with a binary classification (probable/very likely vs not present/unlikely) of adjudicated myocarditis (odds ratio: 2.99; 95% confidence interval (1.01, 8.89) by 28–60 days post-discharge. After a mean (SD, range) duration of follow-up after hospital discharge of 450 (88) days (range 290, 627 days), fewer healthcare workers died or were re-hospitalised (1 (3%) vs 22 (17%); p=0.038) and secondary care referrals for post-COVID-19 syndrome were common (42%) and similar to non-healthcare workers (38%; p=0.934). Discussion Almost one-quarter of the patients were healthcare workers and they were mostly women. Despite less severe acute illness and better antecedent health, compared with non-healthcare workers, healthcare workers had a 3-fold higher likelihood of adjudicated myocarditis, reflecting deep organ involvement of COVID-19. The aetiology of myocardial inflammation may be direct viral myocarditis or myocardial inflammation reflecting multisystem illness. Reverse causality may be relevant in that individuals with reasonably good background health have a greater reserve to withstand COVID-19 such that in those individuals who eventually become sufficiently unwell to require hospital care, the severity of COVID-19 is more pronounced. Healthcare workers have enhanced occupational exposure to SARS-CoV-2 in their workplace which may explain why healthcare workers had evidence of systemic involvement in deep organs, i.e., myocarditis, despite seemingly lower levels of systemic inflammation reflected by CRP. Conclusion Healthcare worker status was independently associated with the likelihood of adjudicated myocarditis, despite better antecedent health. Two in five healthcare workers had a secondary care referral for post-COVID-19 syndrome. Acknowledgements This was an investigator-initiated clinical study funded by the Chief Scientist Office of the Scottish Government (COV/GLA/Portfolio project number 311300). The funder had no role in the design, conduct (non-voting TSC member), data analysis and interpretation, manuscript writing, or dissemination of the results. C.B, C.D., N.S., R.M.T. were supported by the British Heart Foundation (RE/18/6134217). The MRI study involved technologies provided by Siemens Healthcare and the National Institutes of Health. HeartFlow (HeartFlow, Redwood City, CA) provided FFRCT. The study was co-sponsored by NHS Greater Glasgow & Clyde Health Board and the University of Glasgow.

IntroductionMyocardial infarction with no obstructive coronary arteries (MINOCA) occurs in approximately 1 in 9 presentations with acute coronary syndrome. Cardiac MRI is guideline indicated in the investigation of aetiology for MINOCA which includes a spectrum of pathophysiology, for which there is no evidence-based therapy. The presence of ischaemic late gadolinium enhancement is prognostic in myocardial infarction and represents irreversible myocardial damage. However, factors predicting the likelihood of ischaemic late gadolinium enhancement in patients with MINOCA are unclear.Materials and MethodsThe overall aim is to undertake a prospective, registry-based clinical trial in MINOCA [NCT05198791]. Specific aims (1) assess the feasibility of enrolling patients during acute NHS care into a therapeutic trial, (2) in all-comers (registry), undertake multisystem phenotyping using objective, quantitative methods, (3) in patients stratified by invasive evidence of coronary microvascular dysfunction (PressureWire XTM, Abbott), randomise (1:1) to a vasculo-protective intervention (eplerenone 25–50 mg daily for 6 months) or treatment as usual, (4) quantify NT-proBNP (primary outcome, trial), patient reported outcome measures and clinical outcomes at baseline, 30 days and 6 months. Cardiac function and pathology are assessed (<14 days) using multiparametric cardiac MRI (CMR, Siemens AVANTO 1.5T). Late gadolinium enhancement (LGE) patterns are described as ischaemic (sub-endocardial, transmural), non-ischaemic (mid-wall, epicardial), non-pathological (insertion point, septal artery) or no LGE.ResultsOf 82 patients with CMR data recruited between May 2022 and September 2023 (mean age (SD): 60 (11) years; female (%): 78 (63%), 26 (32%) had ischaemic LGE, 6 (7%) non-ischaemic LGE and 34 (41%) no LGE. Factors associated with ischaemic LGE (vs. non-ischaemic vs. no LGE) included ST-elevation at presentation, left ventricular ejection fraction <55%, lower invasive coronary flow reserve (ischaemic LGE: 3.6 (1.8) vs. non-ischaemic LGE: 6.4 (3.3), P = 0.046) and greater peak high sensitivity troponin (median [IQR] – ischaemic LGE: 804 [272, 3359] ng/L, non-ischaemic LGE: 57 [48, 404] ng/L, no LGE: 216 [56, 490] ng/L; P = 0.003).DiscussionThe presence of ischaemic LGE on CMR may help to identify patients at greater risk of adverse outcomes [PMID: 37480903]. The StratMed-MINOCA registry-based clinical trial will provide information on integrating stratified medicine within a MINOCA acute care pathway. The randomised trial will provide novel data on whether short-term (6-month) mineralocorticoid receptor antagonist therapy using eplerenone, has cardio-protective effects.ConclusionIschaemic LGE is common in MINOCA, and associated factors include coronary microvascular dysfunction, peak troponin concentration and left ventricular systolic dysfunction.AcknowledgementsRobert Sykes is supported by funding from the British Heart Foundation Centre of Research Excellence (RE/18/6/34217),NHS Greater Glasgow and Clyde Endowment Funding (GN21CA394) and Abbott Vascular. Professor Berry is supported by a British Heart Foundation Centre of Research Excellence award (RE/18/6/34217) and funding from the Chief Scientist Office, UKRI (COVID-HEART, reference MC/PC/20014), EPSRC (EP/N014642/1; EP/S030875/1) and Wellcome Trust. Andrew Morrow and Colin Berry are supported by the Medical Research Council (MR/S018905/1).