Novel diagnostic approaches and management of coronary microvascular dysfunction

The mechanism underlying ischaemic heart disease (IHD) has been primarily attributed to obstructive coronary artery disease (CAD). However, non-obstructive coronary arteries are identified in >50% of patients undergoing elective coronary angiography, recently leading to growing interest in the investigation and management of angina/ischaemia with non-obstructive coronary arteries (ANOCA/INOCA). INOCA is an umbrella term encompassing a multiple spectrum of possible pathogenetic entities, including coronary vasomotor disorders which consist of two major endotypes: coronary microvascular dysfunction (CMD) and vasospastic angina. Both conditions can coexist and be associated with concomitant obstructive CAD. Particularly, CMD refers to myocardial ischaemia due to reduced vasodilatory capacity of coronary microcirculation secondary to structural remodelling or impaired resting microvascular tone (functional) or a combination of both. CMD is not a benign condition and is more prevalent in women presenting with chronic coronary syndrome compared to men. In this setting, an impaired coronary flow reserve has been associated with increased risk of major adverse cardiovascular events. ANOCA/INOCA patients also experience impaired quality of life and associated increased healthcare costs. Therefore, research in this scenario has led to better definition, classification, and prognostic stratification based on the underlying pathophysiological mechanisms. The development and validation of non-invasive imaging modalities, invasive coronary vasomotor function testing and angiography-derived indices provide a comprehensive characterisation of CMD. The present narrative review aims to summarise current data relating to the diagnostic approach to CMD and provides details on the sequence that therapeutic management should follow.

European Society of Cardiology: the 2023 Atlas of Cardiovascular Disease Statistics

This report from the European Society of Cardiology (ESC) Atlas Project updates and expands upon the 2021 report in presenting cardiovascular disease (CVD) statistics for the ESC member countries. This paper examines inequalities in cardiovascular healthcare and outcomes in ESC member countries utilizing mortality and risk factor data from the World Health Organization and the Global Burden of Disease study with additional economic data from the World Bank. Cardiovascular healthcare data were collected by questionnaire circulated to the national cardiac societies of ESC member countries. Statistics pertaining to 2022, or latest available year, are presented. New material in this report includes contemporary estimates of the economic burden of CVD and mortality statistics for a range of CVD phenotypes. CVD accounts for 11% of the EU's total healthcare expenditure. It remains the most common cause of death in ESC member countries with over 3 million deaths per year. Proportionately more deaths from CVD occur in middle-income compared with high-income countries in both females (53% vs. 34%) and males (46% vs. 30%). Between 1990 and 2021, median age-standardized mortality rates (ASMRs) for CVD decreased by median >50% in high-income ESC member countries but in middle-income countries the median decrease was <12%. These inequalities between middle- and high-income ESC member countries likely reflect heterogeneous exposures to a range of environmental, socioeconomic, and clinical risk factors. The 2023 survey suggests that treatment factors may also contribute with middle-income countries reporting lower rates per million of percutaneous coronary intervention (1355 vs. 2330), transcatheter aortic valve implantation (4.0 vs. 153.4) and pacemaker implantation (147.0 vs. 831.9) compared with high-income countries. The ESC Atlas 2023 report shows continuing inequalities in the epidemiology and management of CVD between middle-income and high-income ESC member countries. These inequalities are exemplified by the changes in CVD ASMRs during the last 30 years. In the high-income ESC member countries, ASMRs have been in steep decline during this period but in the middle-income countries declines have been very small. There is now an important need for targeted action to reduce the burden of CVD, particularly in those countries where the burden is greatest.

Myocardial Ischemia: Differentiating between Epicardial Coronary Artery Atherosclerosis, Microvascular Dysfunction and Vasospasm in the Catheterization Laboratory

Ischemic heart disease is currently the most common cause of mortality and morbidity worldwide. Although myocardial ischemia is classically determined by epicardial coronary atherosclerosis, up to 40% of patients referred for coronary angiography have no obstructive coronary artery disease (CAD). Ischemia with non-obstructive coronary artery disease (INOCA) has typically been underestimated in the past because, until recently, its prognostic significance was not completely clear. This review aims to highlight differences and patterns in myocardial ischemia caused by epicardial obstructive CAD, coronary microvascular dysfunction (CMD) or vasomotor abnormalities and to elucidate the state of the art in correctly diagnosing these different patterns.

Association between gait video information and general cardiovascular diseases: a prospective cross-sectional study

Aims

Cardiovascular disease (CVD) may not be detected in time with conventional clinical approaches. Abnormal gait patterns have been associated with pathological conditions and can be monitored continuously by gait video. We aim to test the association between non-contact, video-based gait information and general CVD status.

Methods and results

Individuals undergoing confirmatory CVD evaluation were included in a prospective, cross-sectional study. Gait videos were recorded with a Kinect camera. Gait features were extracted from gait videos to correlate with the composite and individual components of CVD, including coronary artery disease, peripheral artery disease, heart failure, and cerebrovascular events. The incremental value of incorporating gait information with traditional CVD clinical variables was also evaluated. Three hundred fifty-two participants were included in the final analysis [mean (standard deviation) age, 59.4 (9.8) years; 25.3% were female]. Compared with the baseline clinical variable model [area under the receiver operating curve (AUC) 0.717, (0.690-0.743)], the gait feature model demonstrated statistically better performance [AUC 0.753, (0.726-0.780)] in predicting the composite CVD, with further incremental value when incorporated with the clinical variables [AUC 0.764, (0.741-0.786)]. Notably, gait features exhibited varied association with different CVD component conditions, especially for peripheral artery disease [AUC 0.752, (0.728-0.775)] and heart failure [0.733, (0.707-0.758)]. Additional analyses also revealed association of gait information with CVD risk factors and the established CVD risk score.

Conclusion

We demonstrated the association and predictive value of non-contact, video-based gait information for general CVD status. Further studies for gait video-based daily living CVD monitoring are promising.

Prevalence of Coronary Vasomotor Disorders in Patients With Angina and Nonobstructive Coronary Arteries: A Sydney Experience

BACKGROUND

Patients with angina and non-obstructive coronary arteries (ANOCA) frequently have coronary vasomotor disorders (CVaD), characterised by transient pathological vasoconstriction and/or impaired microvascular vasodilatation. Functional coronary angiography is the gold standard for diagnosing CVaD. Despite recommendations, testing is only available at a limited number of Australian and New Zealand centres. This study aimed to determine the prevalence of CVaDs in an Australian ANOCA population and identify predictive factors associated with specific endotypes.

METHOD

Functional coronary angiography was performed in patients with suspected ANOCA. Vasoreactivity testing was performed using intracoronary acetylcholine provocation. A pressure-temperature sensor guidewire was used for coronary physiology assessment. Comprehensive clinical data on patient characteristics, cardiac risk factors, and symptom profiles was collected before testing.

RESULTS

This prospective observational study at Royal Prince Alfred and Concord Repatriation General Hospital included 110 patients (58±13 years with 63.6% women), with 81.8% (90/110) having a CVaD. Regarding specific ANOCA endotypes, microvascular angina (MVA) occurred in 31.8% (35/110) of cases, vasospastic angina (VSA) in 25.5% (28/110) and a mixed presentation of MVA and VSA in 24.5% (27/110) of patients. Patients with CVaD were found to be older (59±11 vs 51±15, p=0.024), overweight (61.1% vs 15.0%, p<0.001) and had a worse quality of life (EuroQol 5 Dimensions-5 Levels; 0.61 vs 0.67, p=0.043). MVA was associated with being overweight (odds ratio [OR] 4.2 [95% confidence interval [CI] 1.9-9.3]; p=0.015) and ischaemia on stress testing (OR 2.4 [95% CI 1.1-4.3]; p=0.028), while VSA was associated with smoking (OR 9.1 [95% CI 2.21-39.3]; p=0.007).

CONCLUSIONS

Coronary vasomotor disorders are highly prevalent among ANOCA patients. This study highlights the importance of increasing national awareness and the use of functional coronary angiography to evaluate and manage this unique cohort.

Hyperventilation testing in the diagnosis of vasospastic angina: A clinical review and meta-analysis

BACKGROUND

Given the limited access to invasive vasospastic reactivity testing in Western Countries, there is a need to further develop alternative non-invasive diagnostic methods for vasospastic angina (VSA). Hyperventilation testing (HVT) is defined as a class IIa recommendation to diagnose VSA by the Japanese Society of Cardiology.

METHODS

In this systematic review and meta-analysis reported according to the PRISMA statement, we review the mechanisms, methods, modalities and diagnostic accuracy of non-invasive HVT for the diagnostic of VSA.

RESULTS

A total of 106 articles published between 1980 and 2022 about VSA and HVT were included in the systematic review, among which 16 were included in the meta-analysis for diagnostic accuracy. Twelve electrocardiogram-HVT studies including 804 patients showed a pooled sensitivity of 54% (95% confidence intervals [CI]; 30%-76%) and a pooled specificity of 99% (95% CI; 88%-100%). Four transthoracic echocardiography-HVT studies including 197 patients revealed a pooled sensitivity of 90% (95% CI; 82%-94%) and a pooled specificity of 98% (95% CI; 86%-100%). Six myocardial perfusion imaging-HVT studies including 112 patients yielded a pooled sensitivity of 95% (95% CI; 63%-100%) and a pooled specificity of 78% (95% CI; 19%-98%). Non-invasive HVT resulted in a low rate of adverse events, ventricular arrhythmias being the most frequently reported, and were resolved with the administration of nitroglycerin.

CONCLUSIONS

Non-invasive HVT offers a safe alternative with high diagnostic accuracy to diagnose VSA in patients with otherwise undiagnosed causes of chest pain.

Multivessel Coronary Function Testing Increases Diagnostic Yield in Patients With Angina and Nonobstructive Coronary Arteries

BACKGROUND

Invasive CFT is the gold standard for diagnosing coronary vasomotor dysfunction in patients with ANOCA. Most institutions recommend only testing the left coronary circulation. Therefore, it is unknown whether testing multiple coronary territories would increase diagnostic yield.

OBJECTIVES

The aim of this study was to evaluate the diagnostic yield of multivessel, compared with single-vessel, invasive coronary function testing (CFT) in patients with angina and nonobstructive coronary arteries (ANOCA).

METHODS

Multivessel CFT was systematically performed in patients with suspected ANOCA. Vasoreactivity testing was performed using acetylcholine provocation in the left (20 to 200 μg) and right (20 to 80μg) coronary arteries. A pressure-temperature sensor guidewire was used for coronary physiology assessment in all three epicardial vessels.

RESULTS

This multicenter study included a total of 228 vessels from 80 patients (57.8 ± 11.8 years of age, 60% women). Compared with single-vessel CFT, multivessel testing resulted in more patients diagnosed with coronary vasomotor dysfunction (86.3% vs 68.8%; P = 0.0005), coronary artery spasm (60.0% vs 47.5%; P = 0.004), and CMD (62.5% vs 36.3%; P < 0.001). Coronary artery spasm (n = 48) predominated in the left coronary system (n = 38), though isolated right coronary spasm was noted in 20.8% (n = 10). Coronary microvascular dysfunction (CMD), defined by abnormal index of microcirculatory resistance and/or coronary flow reserve, was present 62.5% of the cohort (n = 50). Among the cohort with CMD, 27 patients (33.8%) had 1-vessel CMD, 15 patients (18.8%) had 2-vessel CMD, and 8 patients (10%) had 3-vessel CMD. CMD was observed at a similar rate in the territories supplied by all 3 major coronary vessels (left anterior descending coronary artery = 36.3%, left circumflex coronary artery = 33.8%, right coronary artery = 31.3%; P = 0.486).

CONCLUSIONS

Multivessel CFT resulted in an increased diagnostic yield in patients with ANOCA compared with single-vessel testing. The results of this study suggest that multivessel CFT has a role in the management of patients with ANOCA.

ChaMP-CMD: A Phenotype-Blinded, Randomized Controlled, Cross-Over Trial

BACKGROUND

Angina with nonobstructive coronary arteries is a common condition for which no effective treatment has been established. We hypothesized that the measurement of coronary flow reserve (CFR) allows identification of patients with angina with nonobstructive coronary arteries who would benefit from anti-ischemic therapy.

METHODS

Patients with angina with nonobstructive coronary arteries underwent blinded invasive CFR measurement and were randomly assigned to receive 4 weeks of amlodipine or ranolazine. After a 1-week washout, they crossed over to the other drug for 4 weeks; final assessment was after the cessation of study medication for another 4 weeks. The primary outcome was change in treadmill exercise time, and the secondary outcome was change in Seattle Angina Questionnaire summary score in response to anti-ischemic therapy. Analysis was on a per protocol basis according to the following classification: coronary microvascular disease (CMD group) if CFR<2.5 and reference group if CFR≥2.5. The study protocol was registered before the first patient was enrolled (International Standard Randomised Controlled Trial Number: ISRCTN94728379).

RESULTS

Eighty-seven patients (61±8 years of age; 62% women) underwent random assignment (57 CMD group and 30 reference group). Baseline exercise time and Seattle Angina Questionnaire summary scores were similar between groups. The CMD group had a greater increment (delta) in exercise time than the reference group in response to both amlodipine (difference in delta, 82 s [95% CI, 37-126 s]; P<0.001) and ranolazine (difference in delta, 68 s [95% CI, 21-115 s]; P=0.005). The CMD group reported a greater increment (delta) in Seattle Angina Questionnaire summary score than the reference group in response to ranolazine (difference in delta, 7 points [95% CI, 0-15]; P=0.048), but not to amlodipine (difference in delta, 2 points [95% CI, -5 to 8]; P=0.549).

CONCLUSIONS

Among phenotypically similar patients with angina with nonobstructive coronary arteries, only those with an impaired CFR derive benefit from anti-ischemic therapy. These findings support measurement of CFR to diagnose and guide management of this otherwise heterogeneous patient group.

Angiography-based coronary microvascular assessment with and without intracoronary pressure measurements: a systematic review

BACKGROUND

In recent years, several indices have been proposed for quantifying coronary microvascular resistance. We intended to conduct a comprehensive review that systematically evaluates indices of microvascular resistance derived from angiography.

OBJECTIVE

The objective of this study was to identify and analyze angiography-derived indices of microvascular resistance that have been validated against an invasive reference method. We aimed to compare their limits of agreement with their reference methods and explore their advantages and inherent limitations.

METHODS AND RESULTS

We searched PubMed from inception until 2022 for studies on different techniques for quantifying microvascular resistance. Seven studies met the inclusion criteria. Five studies included techniques that applied calculations based solely on invasive angiography, and were validated against invasively measured thermodilution-derived index of microvascular resistance. The remaining two studies combined angiography with invasively measured intracoronary pressure data, and were validated against invasive Doppler measurements. We converted the ± 1.96 standard deviation limits of agreement with the reference method from the seven studies into percentages relative to the cut-off value of the reference method. The lower limits of agreement for angiography-based methods ranged from - 122 to - 60%, while the upper limits ranged from 74 to 135%. The range of the limits of agreement was considerably lower for the two combined angiography- and pressure-based methods, standing at - 52 to 60% and - 25 to 27%.

CONCLUSION

Our findings suggest that combined angiography- and pressure-based methods provide a more reliable assessment of microvascular resistance compared to methods relying solely on angiography. Central illustration. Comparative assessment of image-based methods quantifying microvascular resistance with and without intracoronary pressure measurements. Angiography-based methods rely on angiography alone to calculate the microvascular resistance by utilizing angiographic frame counting to extrapolate coronary flow (Q) and subsequently deriving distal coronary pressure using fluid dynamic equations. Combined angiography- and pressure-based methods utilize invasive intracoronary pressure gradients measured during rest and maximal vasodilation to determine coronary flow in their calculation of microvascular resistance. The combined methods showed more acceptable levels of agreement with their reference methods compared to angiography-based methods alone.

Angina and Non-Obstructive Coronary Artery (ANOCA) Patients with Coronary Vasomotor Disorders

Angina and Non-Obstructive Coronary Artery (ANOCA) patients often lack a clear explanation for their symptoms, and are frequently discharged with the label of "unspecified chest pain", despite the availability of functional coronary angiography (provocative spasm and microvascular function testing) to identify potential underlying coronary vasomotor disorders. This study compared the outcomes of ANOCA patients with a coronary vasomotor disorder diagnosis post elective coronary angiography to patients discharged with unspecified chest pain. Using the CADOSA (Coronary Angiogram Database of South Australia) registry, consecutive symptomatic patients (n = 7555) from 2012 to 2018 underwent elective angiography; 30% had ANOCA (stenosis <50%). Of this cohort, 9% had documented coronary vasomotor disorders diagnosed, and 91% had unspecified chest pain. Patients with coronary vasomotor disorders were younger and had a similar female prevalence compared with those with unspecified chest pain. New prescriptions of calcium channel blockers and long-acting nitrates were more common for the coronary vasomotor cohort at discharge. In the 3 years following angiography, both groups had similar all-cause mortality rates. However, those with coronary vasomotor disorders had higher rates of emergency department visits for chest pain (39% vs. 15%, p < 0.001) and readmissions for chest pain (30% vs. 10%, p < 0.001) compared with those with unspecified chest pain. This real-world study emphasizes the importance of identifying high-risk ANOCA patients for personalized management to effectively address their symptoms.

The coronary microvascular angina cardiovascular magnetic resonance imaging trial: Rationale and design

BACKGROUND

Coronary microvascular dysfunction may cause myocardial ischemia with no obstructive coronary artery disease (INOCA). If functional testing is not performed INOCA may pass undetected. Stress perfusion cardiovascular MRI (CMR) quantifies myocardial blood flow (MBF) but the clinical utility of stress CMR in the management of patients with suspected angina with no obstructive coronary arteries (ANOCA) is uncertain.

OBJECTIVES

First, to undertake a diagnostic study using stress CMR in patients with ANOCA following invasive coronary angiography and, second, in a nested, double-blind, randomized, controlled trial to assess the effect of disclosure on the final diagnosis and health status in the longer term.

DESIGN

All-comers referred for clinically indicated coronary angiography for the investigation of suspected coronary artery disease will be screened in 3 regional centers in the United Kingdom. Following invasive coronary angiography, patients with ANOCA who provide informed consent will undergo noninvasive endotyping using stress CMR within 3 months of the angiogram.

DIAGNOSTIC STUDY

Stress perfusion CMR imaging to assess the prevalence of coronary microvascular dysfunction and clinically significant incidental findings in patients with ANOCA. The primary outcome is the between-group difference in the reclassification rate of the initial diagnosis based on invasive angiography versus the final diagnosis after CMR imaging.

RANDOMIZED, CONTROLLED TRIAL

Participants will be randomized to inclusion (intervention group) or exclusion (control group) of myocardial blood flow to inform the final diagnosis. The primary outcome of the clinical trial is the mean within-subject change in the Seattle Angina Questionnaire summary score (SAQSS) at 6 months. Secondary outcome assessments include the EUROQOL EQ-5D-5L questionnaire, the Brief Illness Perception Questionnaire (Brief-IPQ), the Treatment Satisfaction Questionnaire (TSQM-9), the Patient Health Questionnaire-4 (PHQ-4), the Duke Activity Status Index (DASI), the International Physical Activity Questionnaire- Short Form (IPAQ-SF), the Montreal Cognitive Assessment (MOCA) and the 8-item Productivity Cost Questionnaire (iPCQ). Health and economic outcomes will be assessed using electronic healthcare records.

VALUE

To clarify if routine stress perfusion CMR imaging reclassifies the final diagnosis in patients with ANOCA and whether this strategy improves symptoms, health-related quality of life and health economic outcomes.

CLINICALTRIALS

GOV: NCT04805814.

Peripheral blood mononuclear cells expression of miR-200c, miR-125b, miR-27b, miR-203, and miR-155 in patients with significant or insignificant coronary artery stenosis

Coronary artery disease (CAD) is one of the principal causes of death worldwide. Among several predisposing factors, inflammation and inflammatory genes play a significant role in disease pathogenesis. Inflammatory microRNAs, small noncoding RNAs involved in regulating inflammation, are promising candidates for understanding pathogenesis of CAD and developing diagnostic biomarkers. The aim of the study was to evaluate the alteration of miR-200c, miR-125b, miR-27b, miR-203 and, miR-155 in patients suffering from coronary artery stenosis and insignificant coronary artery stenosis compared to healthy subjects. In this study we compared expressions of five inflammatory miRNAs in peripheral blood mononuclear cells (PBMCs) of 72 patients suffering significant coronary artery stenosis (CAD), 74 individuals without coronary artery disease and 30 individuals with insignificant coronary artery stenosis (ICAD). After blood collection, PBMCs were isolated and RNA was extracted. Gene expression levels were assessed by SYBR green based real-time PCR. Statistical analysis was performed using R program. Expression levels of miR-200c, miR-203, and miR-155 were lower in subjects with ICAD than that in CAD patients and subjects of the control group. MiR-125b was downregulated in CAD and ICAD groups compared to the control group. PBMC miR-27b was upregulated in the CAD group as compared to the ICAD and control groups. Receiver operating characteristic curve analysis verified potential of three miRNAs in separating subjects with ICAD from CAD patients and healthy individuals. In conclusion, this original investigation suggested that altered expression of these five miRNAs may serve as a novel diagnostic biomarker discriminating clinical presentations of coronary artery diseases.

Microvascular arterial disease of the brain and the heart: a shared pathogenesis

Microvascular arterial disease in the heart manifest as coronary microvascular dysfunction. This condition causes microvascular angina and is associated increased morbidity and mortality. Microvascular arterial disease in the brain is referred to as cerebrovascular small vessel disease. This is responsible for 45% of dementias and 25% of ischaemic strokes. The heart and brain share similar vascular anatomy and common pathogenic risk factors are associated with the development of both coronary microvascular dysfunction and cerebrovascular small vessel disease. Microvascular disease in the heart and brain also appear to share common multisystem pathophysiological mechanisms. Further studies on diagnostic approaches, epidemiology and development of disease-modifying therapy seem warranted.

Complete Percutaneous Coronary Revascularization in Acute Coronary Syndromes With Multivessel Coronary Disease: A Systematic Review

Multivessel disease (MVD) affects approximately 50% of patients with acute coronary syndromes (ACS) and is significantly burdened by poor outcomes and high mortality. It represents a clinical challenge in patient management and decision making and subtends an evolving research area related to the pathophysiology of unstable plaques and local or systemic inflammation. The benefits of complete revascularization are established in hemodynamically stable ACS patients with MVD, and guidelines provide some reference points to inform clinical practice, based on an evidence level that is solid for ST-segment elevation myocardial infarction and less robust for non-ST-segment elevation myocardial infarction and cardiogenic shock. However, several areas of uncertainty remain, such as the optimal timing for complete revascularization or the best guiding strategy for intermediate stenoses. We performed a systematic review of current evidence in the field of percutaneous revascularization in ACS and MVD, also including future perspectives from ongoing trials that will directly compare different timing strategies and investigate the role of invasive and noninvasive guidance techniques. (Complete percutaneous coronary revascularization in patients with acute myocardial infarction and multivessel disease; CRD42022383123).

Initial single-center experience of a standardized protocol for invasive assessment of ischemia and no obstructive coronary artery disease

INTRODUCTION

Coronary vasomotion disorders (CVDs), including microvascular angina (MVA) and vasospastic angina (VSA), account for significant morbidity among patients with non-obstructive coronary artery disease (NOCAD). However, protocols for CVD assessment in clinical practice are seldom standardized and may be difficult to implement.

PURPOSE

To assess the safety and feasibility of a comprehensive coronary function test (CFT) protocol for assessment of CVD and the prevalence of different phenotypes of CVD in patients with angina and NOCAD (ANOCA).

METHODS

Patients with persistent angina referred for invasive coronary angiogram and found to have NOCAD were prospectively recruited and underwent a CFT. Functional parameters (fractional flow reserve, coronary flow reserve and index of myocardial resistance) and coronary vasoreactivity were assessed in all patients.

RESULTS

Of the 20 patients included, the mean age was 63±13 years and 50% were females. Most patients had persistent typical angina and evidence of ischemia in noninvasive tests (75%). The CFT was successfully performed in all subjects without serious complications. Isolated MVA was found in 25%, isolated VSA in 40%, both MVA and VSA in 10% and noncardiac chest pain in 25% of patients. Antianginal therapy was modified after the results of CFT in 70% of patients.

CONCLUSION

A coronary function test was feasible and safe in a cohort of patients with ANOCA. CVD were prevalent in this selected group of patients, and some presented mixed CVD phenotypes. CFT may provide a definitive diagnosis in patients with persistent angina and prompt the stratification of pharmacological therapy.

Definition and epidemiology of coronary microvascular disease

Ischemic heart disease remains one of the leading causes of death and disability worldwide. However, most patients referred for a noninvasive computed tomography coronary angiogram (CTA) or invasive coronary angiogram for the investigation of angina do not have obstructive coronary artery disease (CAD). Approximately two in five referred patients have coronary microvascular disease (CMD) as a primary diagnosis and, in addition, CMD also associates with CAD and myocardial disease (dual pathology). CMD underpins excess morbidity, impaired quality of life, significant health resource utilization, and adverse cardiovascular events. However, CMD often passes undiagnosed and the onward management of these patients is uncertain and heterogeneous. International standardized diagnostic criteria allow for the accurate diagnosis of CMD, ensuring an often overlooked patient population can be diagnosed and stratified for targeted medical therapy. Key to this is assessing coronary microvascular function-including coronary flow reserve, coronary microvascular resistance, and coronary microvascular spasm. This can be done by invasive methods (intracoronary temperature-pressure wire, intracoronary Doppler flow-pressure wire, intracoronary provocation testing) and non-invasive methods [positron emission tomography (PET), cardiac magnetic resonance imaging (CMR), transthoracic Doppler echocardiography (TTDE), cardiac computed tomography (CT)]. Coronary CTA is insensitive for CMD. Functional coronary angiography represents the combination of CAD imaging and invasive diagnostic procedures.

Coronary Arterial Function and Disease in Women With No Obstructive Coronary Arteries

Ischemic heart disease (IHD) is the leading cause of mortality in women. While traditional cardiovascular risk factors play an important role in the development of IHD in women, women may experience sex-specific IHD risk factors and pathophysiology, and thus female-specific risk stratification is needed for IHD prevention, diagnosis, and treatment. Emerging data from the past 2 decades have significantly improved the understanding of IHD in women, including mechanisms of ischemia with no obstructive coronary arteries and myocardial infarction with no obstructive coronary arteries. Despite this progress, sex differences in IHD outcomes persist, particularly in young women. This review highlights the contemporary understanding of coronary arterial function and disease in women with no obstructive coronary arteries, including coronary anatomy and physiology, mechanisms of ischemia with no obstructive coronary arteries and myocardial infarction with no obstructive coronary arteries, noninvasive and invasive diagnostic strategies, and management of IHD.

What an Interventionalist Needs to Know About INOCA

Ischaemia with non-obstructed coronary artery disease (INOCA) remains a diagnostic and therapeutic challenge. An anatomical investigationbased approach to ischaemic heart disease fails to account for disorders of vasomotion. The main INOCA endotypes are microvascular angina, vasospastic angina, mixed (both) or non-cardiac symptoms. The interventional diagnostic procedure (IDP) enables differentiation between clinical endotypes, with linked stratified medical therapy leading to a reduced symptom burden and a better quality of life. Interventionists are therefore well placed to make a positive impact with more personalised care. Despite adjunctive tests of coronary function being supported by contemporary guidelines, IDP use in daily practice remains limited. More widespread adoption should be encouraged. This article reviews a stratified approach to INOCA, describes a streamlined approach to the IDP and highlights some practical and safety considerations.

Management of ischaemia with non-obstructive coronary arteries (INOCA)

Up to half of patients undergoing elective coronary angiography for the investigation of chest pain do not present with evidence of obstructive coronary artery disease. These patients are often discharged with a diagnosis of non-cardiac chest pain, yet many could have an ischaemic basis for their symptoms. This type of ischaemic chest pain in the absence of obstructive coronary artery disease is referred to as INOCA (ischaemia with non-obstructive coronary arteries). This comprehensive review of INOCA management looks at why these patients require treatment, who requires treatment based on diagnostic evaluation, what clinical treatment targets should be considered, how to treat patients using a personalised medicine approach, when to initiate treatment, and where future research is progressing.

Longitudinal myocardial function is more compromised in cardiac syndrome X compared to insignificant CAD: Role of stress echocardiography and calcium scoring

BACKGROUND AND AIM

The aim of this study was to assess the nature of myocardial dysfunction in the cardiac syndrome X (CSX) and insignificant coronary artery disease (ICAD) using dobutamine stress echocardiography (DSE) and coronary calcium scoring (CAC).

METHODS

We prospectively studied 35 consecutive patients who complained of exertional angina, had ≥1 mm ST shift on exercise stress test but normal or no obstructive CAD (<50%) on angiography. Patients were divided into CSX (n = 27) with normal arteries and ICAD (n = 8) with insignificant stenosis.

RESULTS

CSX patients had more females, lower calcium score and less prevalent cardiac risk factors compared to ICAD (p < 0.05 for all). At peak stress, MAPSE and TAPSE failed to increase in both groups. LV septal and lateral s' increased in the two groups but the increment increase was less in CSX than ICAD (p < 0.05) while other diastolic indices did not differ between groups (p > 0.05 for all). CAC correlated modestly with LV and RV systolic velocities: septal s' (r = -0.65, p < 0.001) lateral s' (r = -0.35, p = 0.04) and right s' (r = -0.53, p = 0.005) in CSX, while in ICAD patients only with RV s' (r = -0.58, p = 0.02). On multivariate model, only septal s' OR 1.816 (1.1090-3.820, p = 0.04) proved the most powerful independent predictor of CAC.

CONCLUSIONS

Compromised LV longitudinal systolic velocities were more pronounced and calcium score as a surrogate for atherosclerosis was lower in CSX than ICAD. These findings strengthen the evidence for different pathogenesis of CSX compared to ICAD, with microvascular disease in the former and calcification in the latter.

Untangling the pathophysiologic link between coronary microvascular dysfunction and heart failure with preserved ejection fraction

Coronary microvascular disease (CMD), characterized by impaired coronary flow reserve (CFR), is a common finding in patients with stable angina. Impaired CFR, in the absence of obstructive coronary artery disease, is also present in up to 75% of patients with heart failure with preserved ejection fraction (HFpEF). Heart failure with preserved ejection fraction is a heterogeneous syndrome comprising distinct endotypes and it has been hypothesized that CMD lies at the centre of the pathogenesis of one such entity: the CMD–HFpEF endotype. This article provides a contemporary review of the pathophysiology underlying CMD, with a focus on the mechanistic link between CMD and HFpEF. We discuss the central role played by subendocardial ischaemia and impaired lusitropy in the development of CMD–HFpEF, as well as the clinical and research implications of the CMD–HFpEF mechanistic link. Future prospective follow-up studies detailing outcomes in patients with CMD and HFpEF are much needed to enhance our understanding of the pathological processes driving these conditions, which may lead to the development of physiology-stratified therapy to improve the quality of life and prognosis in these patients.

Guidelines for reasonable and appropriate care in the emergency department (GRACE): Recurrent, low-risk chest pain in the emergency department

This first Guideline for Reasonable and Appropriate Care in the Emergency Department (GRACE-1) from the Society for Academic Emergency Medicine is on the topic: Recurrent, Low-risk Chest Pain in the Emergency Department. The multidisciplinary guideline panel used The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the certainty of evidence and strength of recommendations regarding eight priority questions for adult patients with recurrent, low-risk chest pain and have derived the following evidence based recommendations: (1) for those >3 h chest pain duration we suggest a single, high-sensitivity troponin below a validated threshold to reasonably exclude acute coronary syndrome (ACS) within 30 days; (2) for those with a normal stress test within the previous 12 months, we do not recommend repeat routine stress testing as a means to decrease rates of major adverse cardiac events at 30 days; (3) insufficient evidence to recommend hospitalization (either standard inpatient admission or observation stay) versus discharge as a strategy to mitigate major adverse cardiac events within 30 days; (4) for those with non-obstructive (<50% stenosis) coronary artery disease (CAD) on prior angiography within 5 years, we suggest referral for expedited outpatient testing as warranted rather than admission for inpatient evaluation; (5) for those with no occlusive CAD (0% stenosis) on prior angiography within 5 years, we recommend referral for expedited outpatient testing as warranted rather than admission for inpatient evaluation; (6) for those with a prior coronary computed tomographic angiography within the past 2 years with no coronary stenosis, we suggest no further diagnostic testing other than a single, normal high-sensitivity troponin below a validated threshold to exclude ACS within that 2 year time frame; (7) we suggest the use of depression and anxiety screening tools as these might have an effect on healthcare use and return emergency department (ED) visits; and (8) we suggest referral for anxiety or depression management, as this might have an impact on healthcare use and return ED visits.

Coronary microvascular disease: current concepts of pathophysiology, diagnosis and management

Coronary microvascular disease (CMD) is present in 30% of patients with angina and is associated with increased morbidity and mortality. We now have an improved understanding of the pathophysiology of CMD and the invasive and noninvasive tests that can be used to make the diagnosis. Recent studies have shown that management of CMD guided by physiological testing yields better results than empirical treatment. Despite major advances in diagnosing and stratifying this condition, therapeutic strategies remain limited and poorly defined. This review article discusses recent advances in understanding the pathophysiology of CMD, the modalities that are available to diagnose it clinically, current management options and a look at what is in store for the future.

Ischaemia without obstructive coronary artery disease: the pathophysiology of microvascular dysfunction

PURPOSE OF REVIEW

Nearly one-third of patients presenting with angina have unobstructed epicardial coronary arteries and evidence of coronary microvascular disease. Up until recently, the pathophysiology of coronary microvascular disease has been poorly understood, resulting in limited effective therapeutic options in these patients. As a result, patients with coronary microvascular disease continue to suffer from a poor quality of life and adverse cardiovascular outcomes.

RECENT FINDINGS

Recent mechanistic studies have improved our understanding of the pathophysiology underlying coronary microvascular dysfunction; these studies have implicated the nitric oxide and endothelin pathways as the main drivers. The aim of this article is to review our current understanding of the pathophysiology of ischaemia in patients with coronary microvascular disease.

SUMMARY

Patients with angina who have coronary microvascular disease, but no obstructive coronary artery disease, are unable to augment their coronary blood flow in response to physiological stress, thereby predisposing them to myocardial ischaemia as a result of supply:demand mismatch in the myocardium. In addition to abnormalities of vascular resistance, perturbations in cardiac-coronary coupling also contribute to ischaemia in these patients. Although impaired flow reserve is the diagnostic hallmark, mechanistic studies have demonstrated that the underlying pathophysiology is heterogeneous. At present, two main endotypes have been identified, which can be readily differentiated on the basis of minimal microvascular resistance. A better understanding of the pathophysiology and mechanisms driving ischaemia in coronary microvascular dysfunction may stimulate the development of individualised therapies that may lead to an improvement in patients' quality of life and prognosis.

Peripheral Blood Mononuclear Cells Expression Levels of miR-196a and miR-100 in Coronary Artery Disease Patients

As a chronic inflammatory disease, coronary artery disease (CAD) is a common cause of death worldwide. Dysregulation of microRNA expression levels in peripheral blood mononuclear cells (PBMCs) may contribute to CAD and serve as a potential diagnostic biomarker. Here, we evaluated PBMC expression of two CAD-related inflammatory miRNAs, miR-196a and miR-100, in PBMCs of CAD patients with significant stenosis (CAD, n: 72), patients with insignificant coronary stenosis (ICAD, n: 30), and controls (n: 74) and checked whether they can segregate study groups. MiRNA expression was evaluated using the standard stem-loop RT-qPCR method. MiR-196a expression was downregulated in ICAD compared to CADs and healthy groups. MiR100 expression levels were not different between groups. The receiver operating characteristic (ROC) curve analysis acquainted that miR-196a expression levels in PBMC could segregate CAD individuals or any of its clinical manifestations (i.e. unstable angina, stable angina, acute myocardial infarction) from ICADs. In conclusion, this study reported a distinct miR-196a expression pattern in PBMCs of all patient groups and recommended a biomarker potential for miR-196a in discriminating ICADs from CADs or healthy controls.

Assessment of Vascular Dysfunction in Patients Without Obstructive Coronary Artery Disease: Why, How, and When

Ischemic heart disease secondary to coronary vascular dysfunction causes angina and impairs quality of life and prognosis. About one-half of patients with symptoms and signs of ischemia turn out not to have obstructive coronary artery disease, and coronary vascular dysfunction may be relevant. Adjunctive tests of coronary vasomotion include guidewire-based techniques with adenosine and reactivity testing, typically by intracoronary infusion of acetylcholine. The CorMicA (Coronary Microvascular Angina) trial provided evidence that routine management guided by an interventional diagnostic procedure and stratified therapy improves angina and quality of life in patients with angina but no obstructive coronary artery disease. In this paper, the COVADIS study group provide a comprehensive review of why, how, and when coronary vascular dysfunction should be assessed invasively. They discuss the rationale through a shared understanding of vascular pathophysiology and clinical evidence. They propose a consensus approach to how an interventional diagnostic procedure is performed with focus on practical aspects. Finally, the authors discuss the clinical scenarios in patients with stable and acute coronary syndromes in which measurement of coronary vascular function may be helpful for patient care.

Clinical outcomes in patients with primary stable microvascular angina: is the jury still out?

Several studies have demonstrated that angina chest pain in presence of normal or near normal coronary arteries (NCAs) is mainly related to coronary microvascular dysfunction (CMD). However, controversial findings exist about clinical outcome of these patients. In this article, we critically review characteristics and results of the main clinical studies reporting clinical outcome of stable patients with angina chest pain and non-obstructive coronary artery disease (NO-CAD). Published data indicate that clinical outcomes of these patients are heterogeneous, but those with strict criteria for primary stable microvascular angina (MVA, i.e. typical angina with NCAs mainly related to efforts) do not appear to have an increased mortality or risk of major coronary events. A major determinant of outcome in patients with MVA and NO-CAD seems instead related to non-critical atherosclerotic disease, the presence of which should suggest a more aggressive management of cardiovascular risk factors and preventive management. Future studies should assess whether CMD may have a relevant prognostic role in the latter clinical context and/or in other clinical settings of NO-CAD different from primary stable MVA.

Soluble Urokinase-Type Plasminogen Activator Receptor and High-Sensitivity Troponin Levels Predict Outcomes in Nonobstructive Coronary Artery Disease

Background Multiple biomarkers have been independently and additively associated with major adverse cardiovascular events in patients with coronary artery disease. We investigated the prognostic value of suPAR (soluble urokinase-type plasminogen activator receptor) and hsTnI (high-sensitivity troponin I) levels in symptomatic patients with no obstructive coronary artery disease. We hypothesized that high levels of these biomarkers will be associated with the risk of future adverse outcomes. Methods and Results Plasma levels of suPAR and hsTnI were measured in 556 symptomatic patients with no obstructive coronary artery disease. A biomarker risk score was calculated by counting the number of biomarkers above the median in this cohort (suPAR>2523 pg/mL and hsTnI>2.7 pg/mL). Survival analyses were performed with models adjusted for traditional risk factors. All-cause death and major adverse cardiovascular events (cardiovascular death, myocardial infarction, stroke, and heart failure) served as clinical outcomes over a median follow-up of 6.2 years. Mean age was 57±10 years, 49% of the cohort patients were female, and 68% had a positive stress test. High suPAR and hsTnI levels were independent predictors of all-cause death (hazard ratio=3.2 [95% CI, 1.8-5.7] and 1.3 [95% CI, 1.0-1.7], respectively; both P<0.04) and major adverse cardiovascular events (hazard ratio=2.7 [95% CI, 1.4-5.4] and 1.5 [95% CI, 1.2-2.0], respectively; both P<0.002). Compared with a biomarker risk score of 0, biomarker risk scores of 1 and 2 were associated with 19- and 14-fold increased risk of death and development of major adverse cardiovascular events, respectively. Conclusions Among symptomatic patients with no obstructive coronary artery disease, higher levels of suPAR and hsTnI were independently and additively associated with an increased risk of adverse events. Whether modification of these biomarkers will improve risk in these patients needs further investigation.

1-Year Outcomes of Angina Management Guided by Invasive Coronary Function Testing (CorMicA)

Objectives

The aim of this study was to test the hypothesis that invasive coronary function testing at time of angiography could help stratify management of angina patients without obstructive coronary artery disease.

Background

Medical therapy for angina guided by invasive coronary vascular function testing holds promise, but the longer-term effects on quality of life and clinical events are unknown among patients without obstructive disease.

Methods

A total of 151 patients with angina with symptoms and/or signs of ischemia and no obstructive coronary artery disease were randomized to stratified medical therapy guided by an interventional diagnostic procedure versus standard care (control group with blinded interventional diagnostic procedure results). The interventional diagnostic procedure–facilitated diagnosis (microvascular angina, vasospastic angina, both, or neither) was linked to guideline-based management. Pre-specified endpoints included 1-year patient-reported outcome measures (Seattle Angina Questionnaire, quality of life [EQ-5D]) and major adverse cardiac events (all-cause mortality, myocardial infarction, unstable angina hospitalization or revascularization, heart failure hospitalization, and cerebrovascular event) at subsequent follow-up.

Results

Between November 2016 and December 2017, 151 patients with ischemia and no obstructive coronary artery disease were randomized (n = 75 to the intervention group, n = 76 to the control group). At 1 year, overall angina (Seattle Angina Questionnaire summary score) improved in the intervention group by 27% (difference 13.6 units; 95% confidence interval: 7.3 to 19.9; p < 0.001). Quality of life (EQ-5D index) improved in the intervention group relative to the control group (mean difference 0.11 units [18%]; 95% confidence interval: 0.03 to 0.19; p = 0.010). After a median follow-up duration of 19 months (interquartile range: 16 to 22 months), major adverse cardiac events were similar between the groups, occurring in 9 subjects (12%) in the intervention group and 8 (11%) in the control group (p = 0.803).

Conclusions

Stratified medical therapy in patients with ischemia and no obstructive coronary artery disease leads to marked and sustained angina improvement and better quality of life at 1 year following invasive coronary angiography. (Coronary Microvascular Angina [CorMicA]; NCT03193294)

Dysregulated expression of STAT1, miR-150, and miR-223 in peripheral blood mononuclear cells of coronary artery disease patients with significant or insignificant stenosis

Coronary artery disease (CAD) is a multicellular disease characterized by chronic inflammation. Peripheral blood-mononuclear cells (PBMCs), as a critical component of immune system, actively cross-talk with pathophysiological conditions induced by endothelial cell injury, reflecting in perturbed PBMC expression. STAT1 is believed to be relevant to CAD pathogenesis through regulating key inflammatory processes and modulating STAT1 expression play key roles in fine-tuning CAD-related inflammatory processes. This study evaluated PBMC expressions of STAT1, and its regulators (miR-150 and miR-223) in a cohort including 72 patients with CAD with significant ( ≥ 50%) stenosis, 30 patients with insignificant ( < 50%) coronary stenosis (ICAD), and 74 healthy controls, and assessed potential of PBMC expressions to discriminate between patients and controls. We designed quantitative real-time polymerase chain reaction (RT-qPCR) assays and identified stable reference genes for normalizing PBMC quantities of miR-150, miR-223, and STAT1 applying geNorm algorithm to six small RNAs and five mRNAs. There was no significant difference between CAD and ICAD patients regarding STAT1 expression. However, both groups of patients had higher levels of STAT1 than healthy controls. miR-150 and miR-223 were differently expressed across three groups of subjects and were downregulated in patients compared with healthy controls, with the lowest expression levels being observed in patients with ICAD. ROC curves suggested that PBMC expressions may separate between different groups of study subjects. PBMC expressions also discriminated different clinical manifestations of CAD from ICADs or healthy controls. In conclusion, the present study reported PBMC dysregulations of STAT1, miR-150, and miR-223, in patients with significant or insignificant coronary stenosis and suggested that these changes may have diagnostic implications.

How to Diagnose and Manage Angina Without Obstructive Coronary Artery Disease: Lessons from the British Heart Foundation CorMicA Trial

Patients with symptoms and/or signs of ischaemia but no obstructive coronary artery disease (INOCA) present a diagnostic and therapeutic challenge. Microvascular and/or vasospastic angina are the two most common causes of INOCA; however, invasive coronary angiography lacks the sensitivity to diagnose these functional coronary disorders. In this article, the authors summarise the rationale for invasive testing in the absence of obstructive coronary disease, namely that correct treatment for angina patients starts with the correct diagnosis. They provide insights from the CORonary MICrovascular Angina (CorMicA) study, where an interventional diagnostic procedure was performed with linked medical therapy to improve patient health. Identification of these distinct disorders (microvascular angina, vasospastic angina or non-cardiac chest pain) is key for stratifying INOCA patients, allowing prognostic insights and better patient care with linked therapy based on contemporary guidelines. Finally, they propose a framework to diagnose and manage patients in this common clinical scenario.

Stratified Medical Therapy Using Invasive Coronary Function Testing in Angina: The CorMicA Trial

BACKGROUND

Patients with angina symptoms and/or signs of ischemia but no obstructive coronary artery disease (INOCA) pose a diagnostic and therapeutic challenge.

OBJECTIVES

The purpose of this study was to test whether an interventional diagnostic procedure (IDP) linked to stratified medicine improves health status in patients with INOCA.

METHODS

The authors conducted a randomized, controlled, blinded clinical trial of stratified medical therapy versus standard care in patients with angina. Patients with angina undergoing invasive coronary angiography (standard care) were recruited. Patients without obstructive CAD were immediately randomized 1:1 to the intervention group (stratified medical therapy) or the control group (standard care, IDP sham procedure). The IDP consisted of guidewire-based assessment of coronary flow reserve, index of microcirculatory resistance, fractional flow reserve, followed by vasoreactivity testing with acetylcholine. The primary endpoint was the mean difference in angina severity at 6 months (assessed by the Seattle Angina Questionnaire summary score).

RESULTS

A total of 391 patients were enrolled between November 25, 2016, and November 12, 2017. Coronary angiography revealed obstructive disease in 206 (53.7%). One hundred fifty-one (39%) patients without angiographically obstructive CAD were randomized (n = 76 intervention group; n = 75 blinded control group). The intervention resulted in a mean improvement of 11.7 U in the Seattle Angina Questionnaire summary score at 6 months (95% confidence interval [CI]: 5.0 to 18.4; p = 0.001). In addition, the intervention led to improvements in the mean quality-of-life score (EQ-5D index 0.10 U; 95% CI: 0.01 to 0.18; p = 0.024) and visual analogue score (14.5 U; 95% CI: 7.8 to 21.3; p < 0.001). There were no differences in major adverse cardiac events at the 6-month follow-up (2.6% controls vs. 2.6% intervention; p = 1.00).

CONCLUSIONS

Coronary angiography often fails to identify patients with vasospastic and/or microvascular angina. Stratified medical therapy, including an IDP with linked medical therapy, is routinely feasible and improves angina in patients with no obstructive CAD. (CORonary MICrovascular Angina [CorMicA]; NCT03193294).

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.

Extracardiac findings on coronary computed tomography angiography in patients without significant coronary artery disease

OBJECTIVE

To analyse extracardiac findings in patients without significant coronary artery disease (CAD) in general and in symptomatic patients in particular.

METHODS

We searched the Radiology Information System database for coronary computed tomography angiographies (CTA) performed from 2000-2014 and retrospectively enrolled 3,898 patients without significant CAD (coronary stenosis < 50%) in CTA. In 2,330 symptomatic patients, we analysed the spectrum of extracardiac findings and identified pathologies potentially explaining chest pain. Finally, we investigated variables affecting the number of extracardiac findings detected in CTA.

RESULTS

Overall extracardiac findings were found in 1,177 patients (30.2%; 95%CI, 28.8-31.7%). 94 patients (2.4%; 95%CI, 2.0-2.9%) had extracardiac findings with a recommendation for follow-up, sixteen patients (0.4%; 95%CI, 0.3-0.7%) had incidental urgent, and another three patients (0.1%; 95%CI, 0.1-0.2%) had incidental malignant extracardiac findings. 185 of 2,330 symptomatic patients (7.9%; 95%CI, 6.9-9.1%) revealed extracardiac findings potentially explaining chest pain after exclusion of significant CAD. The number of extracardiac findings increased significantly with patient age (p < 0.001) and the cumulative experience of the CT reader (p < 0.001).

CONCLUSION

30.2% of patients undergoing CTA for exclusion of CAD had ECF, and 7.9% of symptomatic patients without significant CAD on their examination had findings that could potentially explain their symptoms.

KEY POINTS

• Of patients undergoing CTA, 2.8% have relevant incidental extracardiac findings. • CTA could identify the differential diagnosis of chest pain when excluding significant CAD. • Patient age and reader's professional experience influence the number of detected ECFs.

National Institute for Health and Care Excellence updates the stable chest pain guideline with radical changes to the diagnostic paradigm

In the 2016 update of the stable chest pain guideline, the National Institute for Health and Care Excellence (NICE) has made radical changes to the diagnostic paradigm that it-like other international guidelines-had previously placed at the centre of its recommendations. No longer are quantitative assessments of the disease probability considered necessary to determine the need for diagnostic testing and the choice of test. Instead, the recommendation is for no diagnostic testing if chest pain is judged to be 'non-anginal' and CT coronary angiography (CTCA) in patients with 'typical' or 'atypical' chest pain with additional perfusion imaging only if there is uncertainty about the functional significance of coronary lesions. The new emphasis on anatomical-as opposed to functional-testing is driven in large part by cost-effectiveness analysis and despite inevitable resource implications NICE calculates that annual savings for the population of England will be significant. In making CTCA the default diagnostic testing strategy in its updated chest pain guideline, NICE has responded emphatically to calls from trialists for CTCA to have a greater role in the diagnostic pathway of patients with suspected angina.