Invasive Endotyping in Patients With Angina and No Obstructive Coronary Artery Disease: A Randomized Controlled Trial.

BACKGROUND: We investigated the usefulness of invasive coronary function testing to diagnose the cause of angina in patients with no obstructive coronary arteries. METHODS: Outpatients referred for coronary computed tomography angiography in 3 hospitals in the United Kingdom were prospectively screened. After coronary computed tomography angiography, patients with unobstructed coronary arteries, and who consented, underwent invasive endotyping. The diagnostic assessments included coronary angiography, fractional flow reserve (patient excluded if ≤0.80), and, for those without obstructive coronary artery disease, coronary flow reserve (abnormal <2.0), index of microvascular resistance (abnormal ≥25), and intracoronary infusion of acetylcholine (0.182, 1.82, and 18.2 µg/mL; 2 mL/min for 2 minutes) to assess for microvascular and coronary spasm. Participants were randomly assigned to disclosure of the results of the coronary function tests to the invasive cardiologist (intervention group) or nondisclosure (control group, blinded). In the control group, a diagnosis of vasomotor angina was based on medical history, noninvasive tests, and coronary angiography. The primary outcome was the between-group difference in the reclassification rate of the initial diagnosis on the basis of coronary computed tomography angiography versus the final diagnosis after invasive endotyping. The Seattle Angina Questionnaire summary score and Treatment Satisfaction Questionnaire for Medication were secondary outcomes. RESULTS: Of 322 eligible patients, 250 (77.6%) underwent invasive endotyping; 19 (7.6%) had obstructive coronary disease, 127 (55.0%) had microvascular angina, 27 (11.7%) had vasospastic angina, 17 (7.4%) had both, and 60 (26.0%) had no abnormality. A total of 231 patients (mean age, 55.7 years; 64.5% women) were randomly assigned and followed up (median duration, 19.9 [12.6-26.9] months). The clinician diagnosed vasomotor angina in 51 (44.3%) patients in the intervention group and in 55 (47.4%) patients in the control group. After randomization, patients in the intervention group were 4-fold (odds ratio, 4.05 [95% CI, 2.32-7.24]; P<0.001) more likely to be diagnosed with a coronary vasomotor disorder; the frequency of this diagnosis increased to 76.5%. The frequency of normal coronary function (ie, no vasomotor disorder) was not different between the groups before randomization (51.3% versus 50.9%) but was reduced in the intervention group after randomization (23.5% versus 50.9%, P<0.001). At 6 and 12 months, the Seattle Angina Questionnaire summary score in the intervention versus control groups was 59.2±24.2 (2.3±16.2 change from baseline) versus 60.4±23.9 (4.6±16.4 change) and 63.7±23.5 (4.7±14.7 change) versus 66.0±19.3 (7.9±17.1 change), respectively, and not different between groups (global P=0.36). Compared with the control group, global treatment satisfaction was higher in the intervention group at 12 months (69.9±22.8 versus 61.7±26.9, P=0.013). CONCLUSIONS: For patients with angina and no obstructive coronary arteries, a diagnosis informed by invasive functional assessment had no effect on long-term angina burden, whereas treatment satisfaction improved. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03477890.

Restoring microvascular circulation with diagnostic ultrasound and contrast agent: rationale and design of the REDUCE trial.

OBJECTIVES: This study aims to evaluate the efficacy and cost-effectiveness of sonothrombolysis delivered pre and post primary percutaneous coronary intervention (pPCI) on infarct size assessed by cardiac MRI, in patients presenting with STEMI, when compared against sham procedure. BACKGROUND: More than a half of patients with successful pPCI have significant microvascular obstruction and residual infarction. Sonothrombolysis is a therapeutic use of ultrasound with contrast enhancement that may improve microcirculation and infarct size. The benefits and real time physiological effects of sonothrombolysis in a multicentre setting are unclear. METHODS: The REDUCE (Restoring microvascular circulation with diagnostic ultrasound and contrast agent) trial is a prospective, multicentre, patient and outcome blinded, sham-controlled trial. Patients presenting with STEMI will be randomized to one of 2 treatment arms, to receive either sonothrombolysis treatment or sham echocardiography before and after pPCI. This tailored design is based on preliminary pilot data from our centre, showing that sonothrombolysis can be safely delivered, without prolonging door to balloon time. Our primary endpoint will be infarct size assessed on day 4±2 on Cardiac Magnetic Resonance (CMR). Patients will be followed up for 6 months post pPCI to assess secondary endpoints. Sample size calculations indicate we will need 150 patients recruited in total. CONCLUSIONS: This multicentre trial will test whether sonothrombolysis delivered pre and post primary PCI can improve patient outcomes and is cost-effective, when compared with sham ultrasound delivered with primary PCI. The results from this trial may provide evidence for the utilization of sonothrombolysis as an adjunct therapy to pPCI to improve cardiovascular outcomes in STEMI. ANZ Clinical Trial Registration number: ACTRN 12620000807954.

Index of Microcirculatory Resistance to predict microvascular obstruction in STEMI: A systematic review and meta-analysis.

BACKGROUND: Microvascular obstruction (MVO) is an independent predictor of adverse cardiac events after ST-elevation myocardial infarction (STEMI). The Index of Microcirculatory Resistance (IMR) may be a useful marker of MVO, which could simplify the care pathway without the need for Cardiac Magnetic Resonance (CMR). We assessed whether the IMR can predict MVO in STEMI patients. METHODS AND RESULTS: We conducted a systematic review and meta-analysis, including articles where invasive IMR was performed post primary percutaneous coronary intervention (PCI) in addition to MVO assessment with cardiac MRI. We searched PubMed, Scopus, Embase, and Cochrane databases from inception until January 2023. Baseline characteristics, coronary physiology and cardiac MRI data were extracted by two independent reviewers. The random-effects model was used to pool the data. Among 15 articles identified, nine articles (n = 728, mean age 61, 81% male) contained IMR data stratified by MVO. Patients with MVO had a mean IMR of 41.2 [95% CI 32.4-50.4], compared to 25.3 [18.3-32.2] for those without. The difference in IMR between those with and without MVO was 15.1 [9.7-20.6]. Meta-regression analyses demonstrated a linear relationship between IMR and TIMI grade (ß = 0.69 [0.13-1.26]), as well as infarct size (ß = 1.18 [0.24-2.11]) or ejection fraction at 6 months (ß = -0.18 [-0.35 to -0.01]). CONCLUSION: In STEMI, patients with MVO had 15-unit higher IMR than those without. IMR also predicts key prognostic endpoints such as infarct size, MVO, and long-term systolic function.

Protocol Variation in Functional Coronary Angiography Among Patients With Suspected Angina With Non-Obstructive Coronary Arteries: A Nationwide Snapshot of Current Practice Within Australia and New Zealand.

BACKGROUND: Functional coronary angiography (FCA) for endotype characterisation (vasospastic angina [VSA], coronary microvascular disease [CMD], or mixed) is recommended among patients with angina with non-obstructive coronary arteries. Whilst clear diagnostic criteria for VSA and CMD exist, there is no standardised FCA protocol. Variations in testing protocol may limit the widespread uptake of testing, generalisability of results, and expansion of collaborative research. At present, there are no data describing protocol variation across an entire geographic region. Therefore, we aimed to capture current practice variations in the approach to FCA to improve access and standardisation for diagnosis of coronary vasomotor disorders in Australia and New Zealand. METHOD: Between July 2022 and July 2023, we conducted a national survey across all centres in Australia and New Zealand with an active FCA program. The survey captured attitudes towards FCA and protocols used for diagnosis of coronary vasomotor disorders at 33 hospitals across Australia and New Zealand. RESULTS: Survey responses were received from 39 clinicians from 33 centres, with representation from centres within all Australian states and territories and both North and South Islands of New Zealand. A total of 21 centres were identified as having an active FCA program. In general, respondents agreed that comprehensive physiology testing helped inform clinical management. Barriers to program expansion included cost, additional catheter laboratory time, and the absence of an agreed-upon national protocol. Across the clinical sites, there were significant variations in testing protocol, including the technique used (Doppler vs thermodilution), order of testing (hyperaemia resistance indices first vs vasomotor function testing first), rate and dose of acetylcholine administration, routine use of temporary pacing wire, and routine single vs multivessel testing. Overall, testing was performed relatively infrequently, with very little follow-on FCA performed, despite nearly all respondents believing this would be clinically useful. CONCLUSIONS: This survey demonstrates, for the first time, variations in FCA protocol among testing centres across two entire countries. Furthermore, whilst FCA was deemed clinically important, testing was performed relatively infrequently with little or no follow-on testing. Development and adoption of a standardised national FCA protocol may help improve patient access to testing and facilitate further collaborative research within Australia and New Zealand.

Post-stenting fractional flow reserve vs coronary angiography for optimization of percutaneous coronary intervention (TARGET-FFR).

AIMS: A fractional flow reserve (FFR) value ≥0.90 after percutaneous coronary intervention (PCI) is associated with a reduced risk of adverse cardiovascular events. TARGET-FFR is an investigator-initiated, single-centre, randomized controlled trial to determine the feasibility and efficacy of a post-PCI FFR-guided optimization strategy vs. standard coronary angiography in achieving final post-PCI FFR values ≥0.90. METHODS AND RESULTS: After angiographically guided PCI, patients were randomized 1:1 to receive a physiology-guided incremental optimization strategy (PIOS) or a blinded coronary physiology assessment (control group). The primary outcome was the proportion of patients with a final post-PCI FFR ≥0.90. Final FFR ≤0.80 was a prioritized secondary outcome. A total of 260 patients were randomized (131 to PIOS, 129 to control) and 68.1% of patients had an initial post-PCI FFR <0.90. In the PIOS group, 30.5% underwent further intervention (stent post-dilation and/or additional stenting). There was no significant difference in the primary endpoint of the proportion of patients with final post-PCI FFR ≥0.90 between groups (PIOS minus control 10%, 95% confidence interval -1.84 to 21.91, P = 0.099). The proportion of patients with a final FFR ≤0.80 was significantly reduced when compared with the angiography-guided control group (-11.2%, 95% confidence interval -21.87 to -0.35], P = 0.045). CONCLUSION: Over two-thirds of patients had a physiologically suboptimal result after angiography-guided PCI. An FFR-guided optimization strategy did not significantly increase the proportion of patients with a final FFR ≥0.90, but did reduce the proportion of patients with a final FFR ≤0.80.

The Australian New Zealand Spontaneous Coronary Artery Dissection (ANZ-SCAD) Registry - A Multi-Centre Cohort Study: Protocol, Background and Significance.

INTRODUCTION: Spontaneous coronary artery dissection (SCAD) is an under-recognised cause of acute coronary syndrome (ACS) with a strong female predominance. There are currently limited prospective studies and no randomised controlled trials that inform on SCAD's best clinical care. Little is also known about predictors of acute SCAD deterioration or recurrence. We describe the study design of a multi-centre prospective and historical cohort study recruiting patients with SCAD across 15-20 sites in Australia/New Zealand (NZ). The primary aim is to describe the clinical presentation, management and outcomes along with predictors of acute deterioration and recurrence in a large Australian/NZ SCAD cohort, with international data pooling. METHODS AND ANALYSIS: Consented patients diagnosed with SCAD during a hospital admission for an ACS will be prospectively followed at 30 days then yearly, for up to 5 years. Each recruiting site will also retrospectively identify historical cases of SCAD from the proceeding 10 years, with a waiver of consent. For historical cases, data will be collected in a de-identified manner with date of last follow-up or death obtained from the medical records. All cases undergo core laboratory adjudication of coronary angiography and any accompanying imaging to confirm SCAD diagnosis. The primary endpoint will be occurrence of major adverse cardiovascular events; a composite of all-cause mortality, recurrent myocardial infarction (including SCAD recurrence), stroke/transient ischaemic attack, heart failure, cardiogenic shock, cardiac arrest/ventricular arrhythmia, heart transplantation and, repeat/unplanned revascularisation. Secondary endpoints will include each individual primary outcome as well as acute SCAD extension and quality of life/Seattle Angina Score in prospectively recruited participants. Endpoints will be assessed at the end of the hospital admission and at 30-days, 1 year, and median long-term follow-up. ETHICS: Multicentre ethics approval has been granted from the Western Sydney Local Health District Human Research Ethics Committee (2021/ETH00040). DISSEMINATION OF RESULTS: The analysed results will be published in peer-reviewed journals on completion of the historical data collection and then on completion of the prospective data collection. REGISTRATION DETAILS: The ANZ-SCAD registry has been prospectively registered with the Australia and New Zealand Clinical Trials Registry (ACTRN12621000824864).

Genetic dysregulation of endothelin-1 is implicated in coronary microvascular dysfunction.

AIMS: Endothelin-1 (ET-1) is a potent vasoconstrictor peptide linked to vascular diseases through a common intronic gene enhancer [(rs9349379-G allele), chromosome 6 (PHACTR1/EDN1)]. We performed a multimodality investigation into the role of ET-1 and this gene variant in the pathogenesis of coronary microvascular dysfunction (CMD) in patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (CAD). METHODS AND RESULTS: Three hundred and ninety-one patients with angina were enrolled. Of these, 206 (53%) with obstructive CAD were excluded leaving 185 (47%) eligible. One hundred and nine (72%) of 151 subjects who underwent invasive testing had objective evidence of CMD (COVADIS criteria). rs9349379-G allele frequency was greater than in contemporary reference genome bank control subjects [allele frequency 46% (129/280 alleles) vs. 39% (5551/14380); P = 0.013]. The G allele was associated with higher plasma serum ET-1 [least squares mean 1.59 pg/mL vs. 1.28 pg/mL; 95% confidence interval (CI) 0.10-0.53; P = 0.005]. Patients with rs9349379-G allele had over double the odds of CMD [odds ratio (OR) 2.33, 95% CI 1.10-4.96; P = 0.027]. Multimodality non-invasive testing confirmed the G allele was associated with linked impairments in myocardial perfusion on stress cardiac magnetic resonance imaging at 1.5 T (N = 107; GG 56%, AG 43%, AA 31%, P = 0.042) and exercise testing (N = 87; -3.0 units in Duke Exercise Treadmill Score; -5.8 to -0.1; P = 0.045). Endothelin-1 related vascular mechanisms were assessed ex vivo using wire myography with endothelin A receptor (ETA) antagonists including zibotentan. Subjects with rs9349379-G allele had preserved peripheral small vessel reactivity to ET-1 with high affinity of ETA antagonists. Zibotentan reversed ET-1-induced vasoconstriction independently of G allele status. CONCLUSION: We identify a novel genetic risk locus for CMD. These findings implicate ET-1 dysregulation and support the possibility of precision medicine using genetics to target oral ETA antagonist therapy in patients with microvascular angina. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03193294.

Rationale and design of the British Heart Foundation (BHF) Coronary Microvascular Function and CT Coronary Angiogram (CorCTCA) study.

Microvascular and/or vasospastic anginas are relevant causes of ischemia with no obstructive coronary artery disease (INOCA) in patients after computed tomography coronary angiography (CTCA). OBJECTIVES: Our research has 2 objectives. The first is to undertake a diagnostic study, and the second is to undertake a nested, clinical trial of stratified medicine. DESIGN: A prospective, multicenter, randomized, blinded, sham-controlled trial of stratified medicine (NCT03477890) will be performed. All-comers referred for clinically indicated CTCA for investigation of suspected coronary artery disease (CAD) will be screened in 3 regional centers. Following informed consent, eligible patients with angina symptoms are enrolled before CTCA and remain eligible if CTCA excludes obstructive CAD. Diagnostic study: Invasive coronary angiography involving an interventional diagnostic procedure (IDP) to assess for disease endotypes: (1) angina due to obstructive CAD (fractional flow reserve ≤0.80); (2) microvascular angina (coronary flow reserve <2.0 and/or index of microvascular resistance >25); (3) microvascular angina due to small vessel spasm (acetylcholine); (4) vasospastic angina due to epicardial coronary spasm (acetylcholine); and (5) noncoronary etiology (normal coronary function). The IDP involves direct invasive measurements using a diagnostic coronary guidewire followed by provocation testing with intracoronary acetylcholine. The primary outcome of the diagnostic study is the reclassification of the initial CTCA diagnosis based on the IDP. Stratified medicine trial: Participants are immediately randomized 1:1 in the catheter laboratory to therapy stratified by endotype (intervention group) or not (control group). The primary outcome of the trial is the mean within-subject change in Seattle Angina Questionnaire score at 6 months. Secondary outcomes include safety, feasibility, diagnostic utility (impact on diagnosis and certainty), and clinical utility (impact on treatment and investigations). Health status assessments include quality of life, illness perception, anxiety-depression score, treatment satisfaction, and physical activity. Participants who are not randomized will enter a follow-up registry. Health and economic outcomes in the longer term will be assessed using electronic patient record linkage. VALUE: CorCTCA will prospectively characterize the prevalence of disease endotypes in INOCA and determine the clinical value of stratified medicine in this population.

Rationale and design of the Medical Research Council's Precision Medicine with Zibotentan in Microvascular Angina (PRIZE) trial.

Microvascular angina is caused by cardiac small vessel disease, and dysregulation of the endothelin system is implicated. The minor G allele of the non-coding single nucleotide polymorphism (SNP) rs9349379 enhances expression of the endothelin 1 gene in human vascular cells, increasing circulating concentrations of ET-1. The prevalence of this allele is higher in patients with ischemic heart disease. Zibotentan is a potent, selective inhibitor of the ETA receptor. We have identified zibotentan as a potential disease-modifying therapy for patients with microvascular angina. METHODS: We will assess the efficacy and safety of adjunctive treatment with oral zibotentan (10 mg daily) in patients with microvascular angina and assess whether rs9349379 (minor G allele; population prevalence ~36%) acts as a theragnostic biomarker of the response to treatment with zibotentan. The PRIZE trial is a prospective, randomized, double-blind, placebo-controlled, sequential cross-over trial. The study population will be enriched to ensure a G-allele frequency of 50% for the rs9349379 SNP. The participants will receive a single-blind placebo run-in followed by treatment with either 10 mg of zibotentan daily for 12 weeks then placebo for 12 weeks, or vice versa, in random order. The primary outcome is treadmill exercise duration using the Bruce protocol. The primary analysis will assess the within-subject difference in exercise duration following treatment with zibotentan versus placebo. CONCLUSION: PRIZE invokes precision medicine in microvascular angina. Should our hypotheses be confirmed, this developmental trial will inform the rationale and design for undertaking a larger multicenter trial.

Sex differences in procedural and clinical outcomes following rotational atherectomy.

AIM: Evaluate sex differences in procedural net adverse clinical events and long-term outcomes following rotational atherectomy (RA). METHODS AND RESULTS: From August 2010 to 2016, 765 consecutive patients undergoing RA PCI were followed up for a median of 4.7 years. 285 (37%) of subjects were female. Women were older (mean 76 years vs. 72 years; p < .001) and had more urgent procedures (64.6 vs. 47.3%; p < .001). Females received fewer radial procedures (75.1 vs. 85.1%; p < .001) and less intravascular imaging guidance (16.8 vs. 25.0%; p = .008). After propensity score adjustment, the primary endpoint of net adverse cardiac events (net adverse clinical events: all-cause death, myocardial infarction, stroke, target vessel revascularization plus any procedural complication) occurred more often in female patients (15.1 vs. 9.0%; adjusted OR 1.81 95% CI 1.04-3.13; p = .037). This was driven by an increased risk of procedural complications rather than procedural major adverse cardiac events (MACE). Specifically, women were more likely to experience coronary dissection (4.6 vs. 1.3%; p = .008), cardiac tamponade (2.1 vs. 0.4%; p = .046) and significant bleeding (BARC ≥2: 5.3 vs. 2.3). Despite this, overall MACE-free survival was similar between males and females (adjusted HR 1.03; 95% CI 0.80-1.34; p = .81). Procedural complications during RA were associated with almost double the incidence of MACE at long-term follow-up (HR 1.92; 95% CI 1.34-2.77; p < .001). CONCLUSION: Women may be at greater risk of procedural complications following rotational atherectomy. These include periprocedural bleeding episodes and coronary perforation leading to cardiac tamponade. Despite this, the adjusted overall long-term survival free of major adverse cardiac events was similar between males and females.

Systemic microvascular dysfunction in microvascular and vasospastic angina.

Aims: Coronary microvascular dysfunction and/or vasospasm are potential causes of ischaemia in patients with no obstructive coronary artery disease (INOCA). We tested the hypothesis that these patients also have functional abnormalities in peripheral small arteries. Methods and results: Patients were prospectively enrolled and categorised as having microvascular angina (MVA), vasospastic angina (VSA) or normal control based on invasive coronary artery function tests incorporating probes of endothelial and endothelial-independent function (acetylcholine and adenosine). Gluteal biopsies of subcutaneous fat were performed in 81 subjects (62 years, 69% female, 59 MVA, 11 VSA, and 11 controls). Resistance arteries were dissected enabling study using wire myography. Maximum relaxation to ACh (endothelial function) was reduced in MVA vs. controls [median 77.6 vs. 98.7%; 95% confidence interval (CI) of difference 2.3-38%; P = 0.0047]. Endothelium-independent relaxation [sodium nitroprusside (SNP)] was similar between all groups. The maximum contractile response to endothelin-1 (ET-1) was greater in MVA (median 121%) vs. controls (100%; 95% CI of median difference 4.7-45%, P = 0.015). Response to the thromboxane agonist, U46619, was also greater in MVA (143%) vs. controls (109%; 95% CI of difference 13-57%, P = 0.003). Patients with VSA had similar abnormal patterns of peripheral vascular reactivity including reduced maximum relaxation to ACh (median 79.0% vs. 98.7%; P = 0.03) and increased response to constrictor agonists including ET-1 (median 125% vs. 100%; P = 0.02). In all groups, resistance arteries were ≈50-fold more sensitive to the constrictor effects of ET-1 compared with U46619. Conclusions: Systemic microvascular abnormalities are common in patients with MVA and VSA. These mechanisms may involve ET-1 and were characterized by endothelial dysfunction and enhanced vasoconstriction. Clinical trial registration: ClinicalTrials.gov registration is NCT03193294.

Effect of Low-Dose Intracoronary Alteplase During Primary Percutaneous Coronary Intervention on Microvascular Obstruction in Patients With Acute Myocardial Infarction: A Randomized Clinical Trial.

Importance: Microvascular obstruction commonly affects patients with acute ST-segment elevation myocardial infarction (STEMI) and is associated with adverse outcomes. Objective: To determine whether a therapeutic strategy involving low-dose intracoronary fibrinolytic therapy with alteplase infused early after coronary reperfusion will reduce microvascular obstruction. Design, Setting, and Participants: Between March 17, 2016, and December 21, 2017, 440 patients presenting at 11 hospitals in the United Kingdom within 6 hours of STEMI due to a proximal-mid-vessel occlusion of a major coronary artery were randomized in a 1:1:1 dose-ranging trial design. Patient follow-up to 3 months was completed on April 12, 2018. Interventions: Participants were randomly assigned to treatment with placebo (n = 151), alteplase 10 mg (n = 144), or alteplase 20 mg (n = 145) by manual infusion over 5 to 10 minutes. The intervention was scheduled to occur early during the primary PCI procedure, after reperfusion of the infarct-related coronary artery and before stent implant. Main Outcomes and Measures: The primary outcome was the amount of microvascular obstruction (% left ventricular mass) demonstrated by contrast-enhanced cardiac magnetic resonance imaging (MRI) conducted from days 2 through 7 after enrollment. The primary comparison was the alteplase 20-mg group vs the placebo group; if not significant, the alteplase 10-mg group vs the placebo group was considered a secondary analysis. Results: Recruitment stopped on December 21, 2017, because conditional power for the primary outcome based on a prespecified analysis of the first 267 randomized participants was less than 30% in both treatment groups (futility criterion). Among the 440 patients randomized (mean age, 60.5 years; 15% women), the primary end point was achieved in 396 patients (90%), 17 (3.9%) withdrew, and all others were followed up to 3 months. In the primary analysis, the mean microvascular obstruction did not differ between the 20-mg alteplase and placebo groups (3.5% vs 2.3%; estimated difference, 1.16%; 95% CI, -0.08% to 2.41%; P = .32) nor in the analysis of 10-mg alteplase vs placebo groups (2.6% vs 2.3%; estimated difference, 0.29%; 95% CI, -0.76% to 1.35%; P = .74). Major adverse cardiac events (cardiac death, nonfatal MI, unplanned hospitalization for heart failure) occurred in 15 patients (10.1%) in the placebo group, 18 (12.9%) in the 10-mg alteplase group, and 12 (8.2%) in the 20-mg alteplase group. Conclusions and Relevance: Among patients with acute STEMI presenting within 6 hours of symptoms, adjunctive low-dose intracoronary alteplase given during the primary percutaneous intervention did not reduce microvascular obstruction. The study findings do not support this treatment. Trial Registration: ClinicalTrials.gov Identifier: NCT02257294.

Rationale and design of the British Heart Foundation (BHF) Coronary Microvascular Angina (CorMicA) stratified medicine clinical trial.

BACKGROUND: Coronary angiography is performed to assess for obstructive coronary artery disease (CAD), but "nonobstructive CAD" is a common finding. Microvascular or vasospastic angina may be relevant, but routine confirmatory testing is not evidence based and thus rarely performed. AIM: The aim was to assess the effect of stratified medicine guided by coronary function testing on the diagnosis, treatment, and well-being of patients with angina and nonobstructive CAD. DESIGN: The BHF CorMicA trial is a prospective, multicenter, randomized, blinded, sham-controlled trial of stratified medicine (NCT03193294). All-comers referred for elective coronary angiography for investigation of suspected CAD will be screened. Following informed consent, eligible patients with angina and nonobstructive CAD will be randomized 1:1 immediately in the catheter laboratory to either coronary artery function-guided diagnosis and treatment (intervention group) or not (control group). Coronary function will be assessed using a pressure-temperature-sensitive guidewire and adenosine followed by pharmacological testing with intracoronary acetylcholine. Patients will be stratified into endotypes with linked therapy. The primary outcome is change in Seattle Angina Questionnaire score at 6 months. Secondary outcomes include safety, feasibility, diagnostic utility (impact on diagnosis and diagnostic certainty), and clinical utility (impact on treatment and investigations). Health status is a key secondary outcome assessed according to the following domains: quality of life, treatment satisfaction, illness perception, physical activity, and anxiety-depression score. Patients with obstructive disease who are not randomized will form a registry group who will be followed up as a comparator for secondary outcomes including health status. Health and economic outcomes will be evaluated in the longer term using electronic health record linkage. VALUE: CorMicA is a proof-of-concept clinical trial of a disruptive stratified intervention with potential benefits to patients and health care providers.

Balloon Aortic Valvuloplasty in the Transcatheter Valve Era: Single Centre Indications and Early Safety Data in a High Risk Population.

BACKGROUND: The introduction of transcatheter aortic valve implantation (TAVI) has generated a renewed interest in the techniques available to treat high-risk patients with severe aortic stenosis (AS). We report our single centre experience with balloon aortic valvuloplasty (BAV) focussing on indications, procedural success and 30-day outcomes. METHODS: We retrospectively reviewed all patients that underwent BAV procedures at our institution between August 2012 and August 2014. Procedural success and complications were adjudicated according to VARC-2 criteria. RESULTS: Fifty-one consecutive adult patients with severe symptomatic AS underwent a total of 55 BAV procedures. The patients had a mean age of 88±5.7 years and all had extensive comorbidities with a high surgical risk (mean logistic EuroSCORE of 25.22%±14.5%). Indications for BAV included palliation of symptoms n=42 (76%); bridge to definitive valve replacement (n=6, 11%); and evaluation of response (n=6, 11%). The procedure was completed in all patients with no intraprocedural deaths (within 24hours) and low 30-day mortality at 3.9% (n=2). Minor vascular complications occurred in 11.8% (n=6), whilst permanent pacemaker implantation was required in 5.8% (n=3). There were no cases of myocardial infarction, stroke, tamponade, severe aortic regurgitation or major vascular complications during 30-day follow-up. CONCLUSIONS: Balloon aortic valvuloplasty may be performed safely and effectively with high procedural success and low 30-day complications, even in a very high-risk and elderly cohort of patients in whom the role of TAVI is uncertain or inappropriate.

Stratified medicine for acute and chronic coronary syndromes: A patient-tailored approach.

The traditional approach to management of cardiovascular disease relies on grouping clinical presentations with common signs and symptoms into pre-specified disease pathways, all uniformly treated according to evidence-based guidelines ("one-size-fits-all"). The goal of precision medicine is to provide the right treatment to the right patients at the right time, combining data from time honoured sources (e.g., history, physical examination, imaging, laboratory) and those provided by multi-omics technologies. In patients with ischemic heart disease, biomarkers and intravascular assessment can be used to identify endotypes with different pathophysiology who may benefit from distinct treatments. This review discusses strategies for the application of stratified management to patients with acute and chronic coronary syndromes.

Targeted Therapies for Microvascular Disease.

Coronary microvascular dysfunction (CMD) is a common cause of ischemia but no obstructive coronary artery disease that results in an inability of the coronary microvasculature to meet myocardial oxygen demand. CMD is challenging to diagnose and manage due to a lack of mechanistic research and targeted therapy. Recent evidence suggests we can improved patient outcomes by stratifying antianginal therapies according to the diagnosis revealed by invasive assessment of the coronary microcirculation. This review article appraises the evidence for management of CMD, which includes treatment of cardiovascular risk, antianginal therapy and therapy for atherosclerosis.