Ischemia and No Obstructive Coronary Artery Disease: Prevalence and Correlates of Coronary Vasomotion Disorders

Invasive coronary function testing in clinical practice: Implementing the 2024 ESC guidelines on chronic coronary syndromes

Angina with non-obstructive coronary arteries (ANOCA) is increasingly recognized as a significant aspect of chronic coronary syndromes. These patients frequently experience recurrent angina, resulting in high healthcare costs and impaired quality of life. Invasive coronary function testing (ICFT) is able to identify ANOCA endotypes, which can guide treatment and improve quality of life. Despite Class II recommendations for invasive microvascular assessments in the previous 2019 European Society of Cardiology (ESC) Guidelines, ICFT has yet to translate into widespread clinical practice. Patients with ANOCA experience poor quality of life and reduced functional capacity, highlighting the need for earlier ICFT implementation. The 2024 ESC Guidelines now strongly recommend ICFT (Class I, level of evidence B) for patients with non-obstructive coronary arteries and persistent angina despite optimal medical therapy, and for confirming or excluding ANOCA in patients with uncertain diagnoses on non-invasive testing (Class I, level of evidence B). Consequently, a standardized approach to optimize the management of ANOCA patients is warranted. Therefore, this review aims to provide interventional cardiologists with a contemporary review of the literature and a practical guideline on implementation of ICFT. It will discuss the following subjects: the definitions of the different endotypes, an example of an ICFT protocol, discontinuation of medication prior to ICFT, use of radial cocktail, target vessel for testing, acetylcholine injection techniques and rechallenge, adenosine injection techniques, the order of testing, the interpretation of ICFT, safety and feasibility, and the pharmacological treatment.

Refractory angina in women with ischemia and no obstructive coronary artery disease - A report from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) study

Background

Women with suspected ischemia and no obstructive coronary artery disease (INOCA) are often challenging to manage. We aimed to understand mechanisms and treatable pathways of refractory angina.

Methods

The Women's Ischemia Syndrome Evaluation - Coronary Vascular Dysfunction (NCT00832702) recruited women between 2008 and 2015. In a pre-defined subgroup (n = 198) with repeat cardiac magnetic resonance imaging (CMRI) at 1-year, we investigated severity of angina (Seattle Angina Questionnaire-7) in relation to risk factors, baseline invasive coronary function testing, and CMRI parameters. Refractory angina was defined as SAQ-7 score < 75 at baseline and < 10-point improvement at 1-year.

Results

Women with refractory angina (n = 60, 30 %), compared to those without, had lower incomes, and higher proportion of hypertension and nitrate use at 1-year (p < 0.05). They also had significantly lower baseline coronary blood flow (CBF) response to acetylcholine (p < 0.01). Myocardial perfusion reserve index was not different at baseline or follow-up. At 1-year, changes in SAQ domain scores significantly differed between groups, with persistent lack of improvement in physical limitation, disease perception, angina stability, and angina frequency (p < 0.05) in the refractory group. In an age-adjusted regression model, hypertension (OR 4.48; 95 % CI 1.23-16.25; p = 0.02) and abnormal CBF (OR 3.34; 95 % CI 1.04-10.72; p = 0.04) were associated with refractory angina.

Conclusions

Refractory angina is common in women with INOCA. Hypertension and endothelial-dependent microvascular dysfunction are independently associated with a 4- and 3-fold increase in refractory angina at 1-year, respectively. These findings may identify potential treatment targets to reduce angina burden in INOCA.

Non-invasive imaging assessment in angina with non-obstructive coronary arteries (ANOCA)

Due to its significant prevalence and clinical implications, angina with non-obstructive coronary arteries (ANOCA) has become a major focus in modern cardiology. In fact, diagnosing ANOCA presents a significant challenge. The final diagnosis is often difficult, delayed, and frequently necessitates an invasive assessment through coronary angiography. However, recent improvements in non-invasive cardiac imaging allow a diagnosis of ANOCA using a combination of clinical evaluation, anatomical coronary imaging, and functional testing. This narrative review aims to critically assess various non-invasive diagnostic methods and propose a multimodal approach to diagnose ANOCA and tailor appropriate treatments.

A critical review on Moringa oleifera: current status, physicochemical attributes, and food industrial applications

Phytomedicine as an alternative to conventional medications which become more interested for researcher. Moringa Oleifera (M. Oleifera) has been used for centuries to cure a range of illnesses. M. Oleifera, commonly known as the miracle tree, ben oil tree, and drumstick tree, is a Moringaceae family plant whose latin name is Moringa oleifera Lam. It has a high concentration of macro and micronutrients, as well as other bioactive components, all of which are necessary for the body's correct function and the prevention of different disorders. The plant's leaves, seeds, and blooms are all edible and offer a variety of medicinal benefits. Moringa is used to treat diabetes, bacterial, viral, and fungal infections, inflammation, heart disease, cancer, and joint pain. Numerous studies of Moringa oleifera have emphasised its phytochemical components, future possibilities, and usefulness in a variety of domains, including ethnomedicine, whereas this review is a collection of previous discoveries and an update on all previous work.

Prevalence of Angina Pectoris: An Analysis of the National Health Interview Survey (NHIS) Database

BACKGROUND

Angina pectoris remains a significant public health concern, highlighting disparities in cardiovascular health influenced by demographic, socioeconomic, and geographic factors. Analyzing the prevalence of trends is crucial to addressing health inequities and informing targeted interventions. The study of National Health Interview Survey (NHIS) data from 2019 to 2023 allowed us to observe how the pandemic affected cardiovascular care utilization when it decreased in 2020 and later rebounded into 2023 while investigating shifts in reported angina prevalence rates among main groups. Angina pectoris condition-related research requires assessment of current trends for effective health inequities intervention and targeted intervention planning.

OBJECTIVE

This study aims to examine the prevalence of angina pectoris among United States (US) adults from 2019 to 2023 and across demographic, socioeconomic, and geographic factors.

METHOD

Data from the NHIS were analyzed to determine the prevalence of angina pectoris, which was identified through self-reported diagnosis or symptoms. The identification of angina pectoris in the NHIS dataset was based on self-reported physician diagnosis alongside responses to definite survey questions regarding chest pain and discomfort consistent with the symptoms of angina. Angina pectoris was identified in the NHIS dataset based on self-reported physician diagnoses and responses to specific survey questions on chest pain or discomfort consistent with angina. Stratified analyses assessed variations in prevalence across key demographic, socioeconomic, and geographic factors over a five-year period. The statistical analyses included both inferential analyses and descriptive statistics, including hypothesis testing and confidence interval estimation, to evaluate associations and divergences within the data. The prevalence of angina was evaluated across socioeconomic, demographic, and geographic groups using stratified analyses.

RESULTS

The overall prevalence of angina pectoris remained stable (1.5-1.7%) from 2019 to 2023. Higher rates were observed among males (1.8%), older adults (4.5% in those aged 75 years and older), and US-born individuals (1.6%). Disparities observed across race/ethnicity further revealed disparities, with American Indian/Alaska Native individuals (2.1%) and Black individuals (1.2%) showing distinct patterns. Geographic trends highlighted a higher prevalence in areas with high social vulnerability (1.7%). Socioeconomic disparities were notable, with lower-income individuals (<100% federal poverty level (FPL)) experiencing higher prevalence (2.8-3.1%) and elevated rates among those with lower educational attainment. Employment status influenced prevalence, with unemployed individuals showing higher rates (3.4%).

CONCLUSION

The prevalence of angina pectoris reflects persistent disparities across demographic, socioeconomic, and geographic factors. The findings highlight the need for policies that enhance access to preventive cardiovascular care, early screening, and intervention, as well as address the social determinants of health, to minimize disparities in underserved populations.

WNT Signaling Cascade Proteins and Structural and Functional State of The Vascular Bed in Patients With Various Phenotypes of Stable Ischemic Heart Disease

Aim      To evaluate the concentration of the WNT signaling cascade proteins (WNT1, -3a, -4, -5a) and the state of the vasculature by photoplethysmography (PPG) in patients with different phenotypes of stable ischemic heart disease (IHD), with obstructive and non-obstructive coronary artery disease (CAD).Material and methods  This cross-sectional observational study included 80 patients (45-75 years old) with a verified diagnosis of stable IHD. Based on the results of coronary angiography or multislice spiral computed tomography coronary angiography, the patients were divided into two equal groups (n=40), with obstructive IHD (oIHD), and ischemia with no obstructive CAD or angina with no obstructive CAD (INOCA/ANOCA). In the oIHD group, men prevailed (67.5%) while in the INOCA/ANOCA group, women prevailed (57.5%). Noninvasive PPG evaluation of the vasculature was performed, and WNT1, -3a, -4, and -5a concentrations were measured by ELISA in all patients.Results Higher concentrations of the WNT1 and WNT3a proteins were found in patients with oIHD (p<0.001) while the INOCA/ANOCA group had a significantly higher concentration of WNT5a (p=0.001). According to the PPG data, the arterial stiffness index (aSI) significantly differed between the INOCA/ANOCA (7.6 m/s [6.6; 9.35]) and oIHD (9.25 m/s [7.88; 10.33]) groups, p=0.048). The correlation analysis revealed a relationship between WNT1 and the reflectance index RI (ρ=0.359; p=0.014) in IHD patients (oIHD+INOCA/ANOCA). According to the ROC analysis, the curve for WNT3a turned out to be diagnostically significant (sensitivity and specificity of the model were 85.7 and 87.0%, respectively). The cut-off value of WNT3a was 0.183 pg/ml.Conclusion      The results of the study showed that the activation of the canonical WNT cascade (WNT1 and WNT3a) was observed in patients with oIHD, while the non-canonical cascade (WNT5a) was activated in patients with INOCA/ANOCA. The obstructive IHD phenotype can be predicted with a WNT3a value ≥0.183 pg/ml.

Prevalence of Patent Foramen Ovale in Patients with Non-Obstructive Coronary Artery Disease (PROVA) Study

(1) Background: Prevalence of patent foramen ovale (PFO) in the general population is estimated at around 24%. We hypothesized that right-to-left shunting (RLS) resulting from PFO might contribute to angina symptoms in patients with coronary artery spasm (CAS), potentially triggered by vasoactive metabolites. Therefore, the aim of this study was to investigate the prevalence of PFO-related RLS in patients with documented CAS. (2) Methods: This single-center prospective cohort study included patients with documented CAS undergoing transthoracic echocardiography (TTE), including a contrast bubble study between 2021 and 2023. The Seattle Angina Questionnaire (SAQ) and Migraine Disability Assessment (MIDAS) were used to survey patients. (3) Results: RLS (PFO group) was observed in 11 of the 48 patients included (23%). In the PFO group, 64% had epicardial spasm and 36% microvascular spasm. Furthermore, RLS was more prevalent in patients with CAS and concomitant migraine (29%). Remarkably, the density plot of the SAQ summary score showed a worse score for patients with RLS (median of 38 [Q1-Q3: 31-49]) than patients without RLS (median of 49 [Q1-Q3: 41-55]) (p = 0.0282). (4) Conclusions: The prevalence of RLS due to PFO in patients with CAS was in line with the PFO prevalence in the general population, and patients with RLS are more symptomatic according to the SAQ summary score. Whether PFO closure could be beneficial to patients with CAS and concomitant migraine requires further investigation.

Sex-Related Differences in the Prognostic Role of Acetylcholine Provocation Testing

BACKGROUND

Intracoronary provocation testing with acetylcholine (ACh) is helpful to diagnose and risk-stratify patients with ischemia with nonobstructed coronary arteries (NOCA) and myocardial infarction with NOCA. This study explored potential sex-related disparities on the prognostic significance of ACh provocative testing.

METHODS

Consecutive patients with ischemia with NOCA and those with myocardial infarction with NOCA who underwent ACh provocation testing were enrolled. The primary end point was the incidence of major adverse cardiovascular and cerebrovascular events at follow-up. Co-primary end points were angina recurrence and quality of life assessed by 12-month Seattle Angina Questionnaire (SAQ) summary score.

RESULTS

A total of 519 patients (mean age, 61.4±12.1 years; 275 [53.0%] women and 244 [47%] men) were enrolled: 346 (66.7%) with ischemia with NOCA and 173 (33.3%) with myocardial infarction with NOCA. A positive ACh test was observed in 274 (52.8%) patients, with a lower prevalence of epicardial spasm (82 [56.2%] versus 106 [82.8%]) and a higher prevalence of microvascular spasm (64 [43.8%] versus 22 [17.2%]) in women compared with men (P>0.001). After a median 22-month follow-up, major adverse cardiovascular and cerebrovascular events occurred in 53 (10.2%) patients, without significant sex differences (P>0.05). Men with a positive ACh test had a significantly higher rate of major adverse cardiovascular and cerebrovascular events (22 [17.2%] versus 5 [4.3%], P=0.002) compared with those with a negative test; no difference was observed in women (P>0.05) (P for interaction=0.003). Women with a positive test experienced a higher rate of angina recurrence (61 [41.8%] versus 32 [24.8%], P=0.005) and a lower SAQ summary score (82 [interquartile range, 72-90] versus 86 [interquartile range, 78-100], P<0.001) compared with those with a negative result; no difference was observed in men (P>0.05).

CONCLUSIONS

This study revealed the importance of recognizing sex-specific differences in the prognostic value of ACh testing for proper management of coronary vasomotor disorders.

Ischemia with no obstructed coronary arteries and microvascular testing procedures: a review of utility, pharmacotherapy, and current challenges

Ischemia with no obstructive coronary arteries (INOCA) is an increasingly recognized condition in patients presenting with angina and positive stress tests but without significant coronary artery stenosis. This review addresses the pathophysiology, diagnostic approaches, and management strategies associated with INOCA, emphasizing epicardial coronary spasms and coronary microvascular dysfunction (CMD) as underlying mechanisms and myocardial bridging (MB) as a risk factor. Diagnostic modalities include both non-invasive techniques and invasive procedures, such as acetylcholine provocation testing, to differentiate vasospasm from microvascular causes. The paper discusses a potential interference between vasodilators used in trans-radial access and coronary spasm testing. Long-term management approaches for INOCA patients, including pharmacologic therapies and lifestyle interventions, are reviewed.

Coronary Sinus Reducer Improves Angina, Quality of Life, and Coronary Flow Reserve in Microvascular Dysfunction

BACKGROUND

Coronary microvascular dysfunction (CMD) is a common cause of angina with no obstructive coronary artery disease (ANOCA), and effective treatment options are limited.

OBJECTIVES

This study aims to assess the safety and efficacy of the coronary sinus (CS) Reducer (Neovasc, Inc/Shockwave Medical) for treatment of angina in patients with CMD.

METHODS

This Phase II trial enrolled 30 patients with ANOCA, invasively diagnosed CMD, and Canadian Cardiovascular Society (CCS) class 3 to 4 angina despite medical therapy. CMD was defined by coronary flow reserve (CFR) ≤2.5 and/or ≤50% increase in coronary blood flow (CBF) in response to intracoronary infusion of acetylcholine. Invasive coronary microvascular function testing was performed before and at 120 days postimplantation. The primary endpoint was change in microvascular function at 120 days. Secondary endpoints were changes in CCS angina class and Seattle Angina Questionnaire (SAQ) scores.

RESULTS

Mean age was 54.8 ± 11.0 years; 67% (20/30) were women. In patients with low baseline CFR (endothelium-independent CMD), CFR increased significantly from 2.1 (1.95-2.30) to 2.7 (2.45-2.95) (n = 19; P = 0.0011). Patients with abnormal CBF response to acetylcholine at baseline (endothelium-dependent CMD) had an increase in CBF response to acetylcholine: -11.0% (-20.15% to 5.85%) to 11.5% (-4.82% to 39.29%) (n = 11; P = 0.042). There was a significant improvement in CCS angina class from 4.0 (3.25-4.0) to 2.0 (2.0-3.0) (P < 0.001) and increase in each domain of the SAQ questionnaire (P < 0.006 for all).

CONCLUSIONS

This study demonstrates that the CS Reducer is associated with significant improvement in angina, quality of life, and coronary microvascular function in patients with CMD and may emerge as a novel therapy for patients with ANOCA.

Exploring patients' views regarding the support and rehabilitation needs of people living with myocardial ischaemia and no obstructive coronary arteries: a qualitative interview study

OBJECTIVES

This study aimed to generate new qualitative insights to understand the rehabilitation needs of people living with a confirmed or presumed diagnosis of ischaemia with no obstructive coronary arteries (INOCA), explore which aspects of current cardiovascular prevention and rehabilitation programmes could meet the needs of people with INOCA and where adjustments (if any) may be appropriate.

DESIGN

Semistructured qualitative interview study.

PARTICIPANTS

Interviews were undertaken (n=17; 88% female, age range 31-69 years) with people with a confirmed or presumed diagnosis of INOCA.

RESULTS

Findings highlighted concerns around a lack of evidence-based guidance for cardiovascular prevention and rehabilitation programmes for patients with INOCA. Participants expressed a desire for modular cardiovascular prevention and rehabilitation programmes that could be accessed flexibly to accommodate episodic fluctuations in symptoms. Participants suggested that existing cardiovascular prevention and rehabilitation programme content needed adjustment including enhanced psychosocial support, supervised low-impact physical activity and specialist dietary advice and medication reviews. Additional elements specific to INOCA should be made available as appropriate including acute care planning and a module to provide information and support for female-specific issues. The importance of involving INOCA patients in the codesign of future programmes and associated training was emphasised.

CONCLUSIONS

People with INOCA are willing to engage with cardiovascular prevention and rehabilitation programmes and express a desire for more support. This patient group shares some barriers to rehabilitation programme attendance with other cardiac patient groups, but they also have specific concerns about the need for improved professional knowledge and evidence-based guidance regarding the management of INOCA. Cardiovascular rehabilitation programmes need to be delivered flexibly and individually tailored to ensure the relapsing and remitting nature of INOCA and associated support needs are addressed.

Developing a Women's Heart Center With a Specialization in Coronary Microvascular and Vasomotor Dysfunction: If You Build It, They Will Come

BACKGROUND

Women's Heart Centers (WHC) are comprehensive, multidisciplinary care centers designed to close the existing gap in women's cardiovascular care. The WHC at The Christ Hospital Heart and Vascular Institute (TCH-WHC) in Cincinnati, Ohio was established in October of 2020, and is a specialized coronary microvascular and vasomotor dysfunction (CMVD) program.

METHODS

The TCH-WHC focuses its efforts across five pillars: patient care, research, education, community outreach and advocacy, and grants and philanthropy. These areas, centered around providing specalized CMVD care and treatment have allowed for substantial growth.

RESULTS

From October 2020-December 2023, TCH-WHC saw a total of 3219 patients, 42% of which were apart of the CMVD program. Since establishment, patient volume has consistently increased year over year.

CONCLUSION

The CMVD program at TCH-WHC is one of the fastest growing in the U. S. and is nationally recognized for specialized clinical care, diagnostics, and research. The goal of this review is to provide an overview of the TCH-WHC structure that allows for the establishment and growth of a CMVD program and to outline core activities supporting the TCH-WHC approach.

Genetic associations of cardiovascular risk genes in European patients with coronary artery spasm

BACKGROUND

Coronary artery spasm (CAS) is a frequent finding in patients presenting with angina pectoris. Although the pathogenesis of CAS is incompletely understood, previous studies suggested a genetic contribution. Our study aimed to elucidate genetic variants in a cohort of European patients with angina and unobstructed coronary arteries who underwent acetylcholine (ACh) provocation testing.

METHODS

A candidate association analysis of 208 genes previously associated with cardiovascular conditions was performed using genotyped and imputed variants in patients grouped in epicardial (focal, diffuse) CAS (n = 119) and microvascular CAS (n = 87). Patients with a negative ACh test result (n = 45) served as controls.

RESULTS

We found no association below the genome-wide significance threshold of p < 5 × 10-8, thus not confirming variants in ALDH2, NOS3, and ROCK2 previously reported in CAS patients of Asian ancestry. However, the analysis identified suggestive associations (p < 10-05) for the groups of focal epicardial CAS (CDH13) and diffuse epicardial CAS (HDAC9, EDN1). Downstream analysis of the potential EDN1 risk locus showed that CAS patients have significantly increased plasma endothelin-1 levels (ET-1) compared to controls. An EDN1 haplotype comprising rs9349379 and rs2070698 was significantly associated to ET-1 levels (p = 0.01).

CONCLUSIONS

In summary, we suggest EDN1 as potential genetic risk loci for patients with diffuse epicardial CAS, and European ancestry. Plasma ET-1 levels may serve as a potential cardiac marker.

Diagnostic Yield of Comprehensive Coronary Function Testing in Patients with Angina and Unobstructed Coronary Arteries: Endotype Characterisation and Clinical Implications

Background

Coronary functional disorders (CFD) are significant contributors to angina with non-obstructed coronary arteries (ANOCA). Various endotypes, such as epicardial or microvascular spasm and/or coronary microvascular dysfunction (CMD), have been identified. Previous studies have shown a high prevalence of CFD in ANOCA cases, but often lacked comprehensive coronary functional testing (CFT), which ideally includes coronary spasm provocation testing and CMD assessment. This study aims to investigate the prevalence of CFD and to characterise endotypes in ANOCA patients using comprehensive CFT.

Methods

A total of 89 consecutive ANOCA patients (mean age 64, 69% women) who underwent comprehensive CFT were enrolled. CFT comprised acetylcholine (ACh) spasm provocation testing and assessment of coronary flow reserve (CFR) and hyperaemic microvascular resistance using Doppler technique.

Results

CFT identified at least one coronary vasomotion disorder in 91% of patients with ANOCA. Among them, microvascular spasm was the most common endotype (61%), followed by CMD (43%). Only 9% of patients had isolated CMD with the remaining CMD patients also showing coronary spasm. Low CFR was mainly associated with high resting coronary flow rather than impaired hyperaemic flow (R -0.60, p<0.0001). Additionally, 48% of patients with microvascular spasm exhibited moderate to severe coronary tortuosity.

Conclusion

CFT provides a high diagnostic yield of CFD in ANOCA patients. Coronary spasm, particularly microvascular spasm, is the most frequent endotype. Patients with isolated CMD are rare, highlighting the importance of spasm testing in the ANOCA population.

Correlation between coronary microvascular dysfunction and cardiorespiratory fitness in patients with ST-segment elevation myocardial infarction

We retrospectively investigated the relationship between cardiopulmonary exercise testing (CPET) parameters and coronary microvascular dysfunction (CMD) using a novel angiography-based index of microcirculatory resistance (AccuIMR) in patients with ST-elevation myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI) with complete revascularization. In 418 patients, the culprit vessel AccuIMR was calculated after successful primary PCI. CPET was conducted 44.04 ± 19.28 days after primary PCI. Overall, 157 patients (37.6%) showed elevated AccuIMR (> 40 U) in the culprit vessels. The LVEF was significantly lower in the CMD group than in the Non-CMD group. The CMD group showed worse results in VO2peak, peak O2-pulse, and VE/VCO2 slope than the Non-CMD group. Spearman correlation analysis suggested that VO2peak (r = -0.354), peak O2-pulse (r = -0.385) and VE/VCO2 slope (r = 0.294) had significant linear correlations with AccuIMR (P < 0.001). Multivariable logistic regression analysis showed that AccuIMR was the independent predictor of reduced VO2peak and elevated VE/VCO2 slope. The proportions of positive and equivocal ECG results and early O2-pulse flattening in the CMD group were significantly higher than those in the Non-CMD group, and AccuIMR was the only independent predictor of these ischemia-relating indicators, suggesting that patients with CMD had significant noninvasively detectable myocardial ischemia.

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.

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.

The Diagnostic Value of ECG Characteristics for Vasospastic and Microvascular Angina: A Systematic Review

BACKGROUND

Coronary vascular dysfunction comprises VSA and/or MVA and is more common in women than in men with angina without obstructive coronary artery disease (ANOCA). Invasive coronary function testing is considered the reference test for diagnosis, but its burden on patients is large. We aimed to investigate the potential of electrocardiography (ECG) as noninvasive marker for vasospastic angina (VSA) and microvascular angina (MVA) diagnosis.

METHODS

We systematically screened Pubmed and EMBASE databases for studies reporting on ECG characteristics in ANOCA patients with (a suspicion of) coronary vascular dysfunction. We assessed study quality using QUADAS-2. We extracted data on diagnostic values of different ECG characteristics and analyzed whether the studies were sex-stratified.

RESULTS

Thirty publications met our criteria, 13 reported on VSA and 17 on MVA. The majority addressed repolarization-related ECG parameters. Only 1 of the 13 VSA papers and 4 of the 17 MVA papers showed diagnostic accuracy measures of the ECG characteristics. The presence of early repolarization, T-wave alternans, and inverted U waves showed of predictive value for VSA diagnosis. The QTc interval was predictive for MVA diagnosis in all six studies reporting on QTc interval. Sex-stratified results were reported in only 5 of the 30 studies and 3 of those observed sex-based differences.

CONCLUSIONS

ECG features are not widely evaluated in diagnostic studies for VSA and MVA. Those features predictive for VSA and MVA diagnosis mostly point to repolarization abnormalities and may contribute to noninvasive risk stratification.

Evaluating Ischemic Heart Disease in Women: Focus on Angina With Nonobstructive Coronary Arteries (ANOCA)

Ischemic heart disease (IHD) is common in women, and cardiovascular disease is a leading cause of morbidity and mortality. While obstructive coronary artery disease is the most common form of IHD, millions of women suffer from angina with nonobstructive coronary arteries (ANOCA), an umbrella term encompassing multiple nonatherosclerotic disorders of the coronary tree. The underlying pathology leading to ischemia in these syndromes may be challenging to diagnose, leaving many women without a diagnosis despite persistent symptoms that impact quality of life and adversely affect long-term cardiovascular prognosis. In the last decade, there have been significant advances in the recognition and diagnostic evaluation of ANOCA. Despite these advances, the standard approach to evaluating suspected IHD in women continues to focus predominantly on the assessment of atherosclerotic coronary artery disease, leading to missed opportunities to accurately diagnose and treat underlying coronary vasomotor disorders. The goal of this review is to describe advances in diagnostic testing that can be used to evaluate angina in women and present a pragmatic diagnostic algorithm to guide evaluation of ANOCA in symptomatic patients. The proposed approach for the assessment of ANOCA is consistent with prior expert consensus documents and guidelines but is predicated on the medical interview and pretest probability of disease to inform a personalized diagnostic strategy.

Beyond Coronary Artery Disease: Assessing the Microcirculation

Ischemic heart disease (IHD) affects more than 20 million adults in the United States. Although classically attributed to atherosclerosis of the epicardial coronary arteries, nearly half of patients with stable angina and IHD who undergo invasive coronary angiography do not have obstructive epicardial coronary artery disease. Ischemia with nonobstructive coronary arteries is frequently caused by microvascular angina with underlying coronary microvascular dysfunction (CMD). Greater understanding the pathophysiology, diagnosis, and treatment of CMD holds promise to improve clinical outcomes of patients with ischemic heart disease.

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.

Visual Estimates of Coronary Slow Flow Are Not Associated With Invasive Wire-Based Diagnoses of Coronary Microvascular Dysfunction

BACKGROUND

Coronary slow flow (CSF) by invasive coronary angiography is frequently understood to be an indicator of coronary microvascular dysfunction (CMD) in patients with ischemia with nonobstructive coronary arteries. However, the relationship between visual estimates of CSF and quantitative wire-based invasive diagnosis of CMD is uncertain.

METHODS

We prospectively enrolled adults aged ≥18 years with stable ischemic heart disease who were referred for invasive coronary angiography. Individuals with ≥50% epicardial coronary artery stenosis were excluded. Invasive coronary angiography was reviewed for CSF, defined as ≥3 cardiac cycles to opacify distal vessels with contrast. Coronary function testing was performed in the left anterior descending coronary artery using bolus coronary thermodilution techniques to measure coronary flow reserve (CFR) and the index of microcirculatory resistance (IMR). Invasively determined CMD was defined as abnormal CFR (<2.5), abnormal IMR (≥25), or both.

RESULTS

Among 104 participants, the median age was 61.5 years and 79% were female. The median CFR was 3.6 (interquartile range, 2.5-4.7) and the median IMR was 21 (interquartile range, 13.3-28.0). Overall, 24.0% of participants had abnormal CFR, 34.6% had abnormal IMR, and 48.1% had a final diagnosis of invasively determined CMD. CSF was present in 23 participants (22.1%). The proportions of patients with CMD (56.5% versus 45.7%; P=0.36), abnormal CFR (17.4% versus 25.9%; P=0.40), and abnormal IMR (43.5% versus 32.1%; P=0.31) were not different in patients with versus without CSF.

CONCLUSIONS

Among patients with ischemia with nonobstructive coronary artery, CSF was not associated with abnormal CFR, IMR, or either abnormal CFR or IMR. CSF is not a reliable angiographic surrogate of abnormal CFR or IMR as determined by invasive, wire-based physiology testing.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT03537586.

INOCA: Ischemia in non-obstructive coronary arteries

This article provides a summary of the clinical spectrum of no obstructive coronary arteries. We describe the pathologies, invasive and noninvasive assessment, and management strategies.

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.

Nonobstructive epicardial coronary artery disease: an evolving concept in need of diagnostic and therapeutic guidance

For decades, we have been treating patients presenting with angina and concerning electrocardiographic changes indicative of ischemia or injury, in whom no culprit epicardial coronary stenosis was found during diagnostic coronary angiography. Unfortunately, the clinical outcomes of these patients were not better than those with recognized obstructive coronary disease. Improvements in technology have allowed us to better characterize these patients. Consequently, an increasing number of patients with ischemia and no obstructive coronary artery disease (INOCA) or myocardial infarction in the absence of coronary artery disease (MINOCA) have now gained formal recognition and are more commonly encountered in clinical practice. Although both entities might share functional similarities at their core, they pose significant diagnostic and therapeutic challenges. Unless we become more proficient in identifying these patients, particularly those at higher risk, morbidity and mortality outcomes will not improve. Though this field remains in constant flux, data continue to become available. Therefore, we thought it would be useful to highlight important milestones that have been recognized so we can all learn about these clinical entities. Despite all the progress made regarding INOCA and MINOCA, many important knowledge gaps continue to exist. For the time being, prompt identification and early diagnosis remain crucial in managing these patients. Even though we are still not clear whether intensive medical therapy alters clinical outcomes, we remain vigilant and wait for more data.

Predicting the response to acetylcholine in ischemia or infarction with non-obstructive coronary arteries: The ABCD score

BACKGROUND AND AIMS

Acetylcholine (ACh) provocation testing can detect vasomotor disorders in patients with ischemia and non-obstructed coronary arteries (INOCA) or myocardial infarction and non-obstructed coronary arteries (MINOCA). We aimed to derive and validate a simple risk score to predict a positive ACh test response.

METHODS

We prospectively enrolled consecutive INOCA and MINOCA patients undergoing ACh provocation testing. Patients were split in two cohorts (derivation and validation) according to time of enrolment. The score was derived in 386 patients (derivation cohort) and then validated in 165 patients (validation cohort).

RESULTS

551 patients were enrolled, 371 (67.3%) INOCA and 180 (32.7%) MINOCA. ACh test was positive in 288 (52.3%) patients. MINOCA, myocardial bridge (MB), C-reactive protein (CRP) and dyslipidaemia were independent predictors of a positive ACh test in the derivation cohort. The ABCD (Acute presentation, Bridge, CRP, Dyslipidaemia) score was derived: 2 points were assigned to MINOCA, 3 to MB, 1 to elevated CRP and 1 to dyslipidaemia. The ABCD score accurately identified patients with a positive ACh test response with an AUC of 0.703 (CI 95% 0.652-0.754,p < 0.001) in the derivation cohort, and 0.705 (CI 95% 0.626-0.784, p < 0.001) in the validation cohort. In the whole population, an ABCD score ≥4 portended 94.3% risk of a positive ACh test and all patients with an ABCD score ≥6 presented a positive test.

CONCLUSIONS

The ABCD score could avoid the need of ACh provocation testing in patients with a high score, reducing procedural risks, time, and costs, and allowing the implementation of a tailored treatment strategy. These results are hypothesis generating and further research involving larger cohorts and multicentre trials is needed to validate and refine the ABCD score.

Chemokine Fractalkine and Non-Obstructive Coronary Artery Disease-Is There a Link?

Non-obstructive coronary artery disease (NO-CAD) constitutes a heterogeneous group of conditions collectively characterized by less than 50% narrowing in at least one major coronary artery with a fractional flow reserve (FFR) of ≤0.80 observed in coronary angiography. The pathogenesis and progression of NO-CAD are still not fully understood, however, inflammatory processes, particularly atherosclerosis and microvascular dysfunction are known to play a major role in it. Chemokine fractalkine (FKN/CX3CL1) is inherently linked to these processes. FKN/CX3CL1 functions predominantly as a chemoattractant for immune cells, facilitating their transmigration through the vessel wall and inhibiting their apoptosis. Its concentrations correlate positively with major cardiovascular risk factors. Moreover, promising preliminary results have shown that FKN/CX3CL1 receptor inhibitor (KAND567) administered in the population of patients with ST-elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI), inhibits the adverse reaction of the immune system that causes hyperinflammation. Whereas the link between FKN/CX3CL1 and NO-CAD appears evident, further studies are necessary to unveil this complex relationship. In this review, we critically overview the current data on FKN/CX3CL1 in the context of NO-CAD and present the novel clinical implications of the unique structure and function of FKN/CX3CL1 as a compound which distinctively contributes to the pathomechanism of this condition.

Coronary Spasm Testing with Acetylcholine: A Powerful Tool for a Personalized Therapy of Coronary Vasomotor Disorders

Coronary vasomotor disorders (CVD) are characterized by transient hypercontraction of coronary vascular smooth muscle cells, leading to hypercontraction of epicardial and/or microvascular coronary circulation. CVDs play a relevant role in the pathogenesis of ischemia, angina and myocardial infarction with non-obstructive coronary arteries. Invasive provocative testing with intracoronary Acetylcholine (ACh) administration is the gold standard tool for addressing CVD, providing relevant therapeutic and prognostic implications. However, safety concerns preclude the widespread incorporation of the ACh test into clinical practice. The purpose of this review is to shed light on the pathophysiology underlying CVD and on the clinical role of the ACh test, focusing on safety profile and prognostic implications. We will also discuss contemporary evidence on the management of CVD and the role of the ACh test in driving a personalized approach of patients with CVD.

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.

The diagnosis and treatment of women with recurrent cardiac ischemia and normal coronary arteries

Cardiac disease is the leading cause of death in women. Among women with recurrent chest pain, abnormal electrocardiograms, and/or stress tests who undergo coronary angiography, as many as 50% have normal or <50% coronary artery obstructive disease. Pharmacologic stress assessment of coronary artery flow reserve in these women frequently demonstrates an inability to increase blood flow to >2.5 times normal flow. Contributory factors include abnormal epicardial or microvascular reactivity, microvascular remodeling or rarefaction, autonomic dysfunction, or coronary plaque rupture/erosion. Assessment is necessary of serum biomarkers and coronary artery flow reserve, fractional flow reserve, microvascular resistance, and epicardial/microvascular spasm. Aggressive treatment of women with positive tests is necessary because these women have an increased incidence of recurrent chest pain, repeated hospitalizations and coronary angiograms, and cardiac death.

Beyond Coronary Artery Disease: Assessing the Microcirculation

Ischemic heart disease (IHD) affects more than 20 million adults in the United States. Although classically attributed to atherosclerosis of the epicardial coronary arteries, nearly half of patients with stable angina and IHD who undergo invasive coronary angiography do not have obstructive epicardial coronary artery disease. Ischemia with nonobstructive coronary arteries is frequently caused by microvascular angina with underlying coronary microvascular dysfunction (CMD). Greater understanding the pathophysiology, diagnosis, and treatment of CMD holds promise to improve clinical outcomes of patients with ischemic heart disease.

Noninvasive evaluation of dynamic microvascular dysfunction in ischemia and no obstructive coronary artery disease patients with suspected vasospasm

INTRODUCTION

In patients with ischemia and no obstructive coronary artery disease (INOCA), a dynamic coronary microvascular dysfunction (CMD) is frequent but difficult to capture by noninvasive means.The aim of our study was to assess dynamic CMD in INOCA patients with stress echocardiography after vasoconstrictive and vasodilator stimuli.

METHODS

In this prospective single-center study, we have enrolled 40 INOCA patients (age 56.3 ± 13 years, 32 women). All participants underwent stress echocardiography with hyperventilation (HYP), followed by supine bicycle exercise (HYP+EXE) and adenosine (ADO). Stress echocardiography included an assessment of regional wall motion abnormality (RWMA) and coronary flow velocity (CFV) in the distal left anterior descending (LAD) coronary artery.

RESULTS

HYP induced a 30% increase in rate pressure product (rest = 10 244 ± 2353 vs. HYP = 13 214 ± 3266 mmHg x bpm, P  < 0.001) accompanied by a paradoxical reduction in CFV (HYP< rest) in 21 patients (52%). HYP alone was less effective than HYP+EXE in inducing anginal pain (6/40, 15% vs. 10/40, 25%, P  = 0.046), ST segment changes (6/40, 15% vs. 24/40, 60%, P  < 0.001), and RWMA (6/40, 15% vs. 13/40, 32.5%, P  = 0.008). ADO-induced vasodilation was preserved (≥2.0) in all patients.

CONCLUSION

In patients with INOCA, a coronary vasoconstriction after HYP is common, in absence of structural CMD detectable with ADO. HYP+EXE test represents a more powerful ischemia inducer than HYP alone. Stress echocardiography with LAD-CFV may allow the noninvasive assessment of dynamic and structural coronary microcirculation during stress.

Rethinking False Positive Exercise Electrocardiographic Stress Tests by Assessing Coronary Microvascular Function

BACKGROUND

Exercise electrocardiographic stress testing (EST) has historically been validated against the demonstration of obstructive coronary artery disease. However, myocardial ischemia can occur because of coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease.

OBJECTIVES

The aim of this study was to assess the specificity of EST to detect an ischemic substrate against the reference standard of coronary endothelium-independent and endothelium-dependent microvascular function in patients with angina with nonobstructive coronary arteries (ANOCA).

METHODS

Patients with ANOCA underwent invasive coronary physiological assessment using adenosine and acetylcholine. CMD was defined as impaired endothelium-independent and/or endothelium-dependent function. EST was performed using a standard Bruce treadmill protocol, with ischemia defined as the appearance of ≥0.1-mV ST-segment depression 80 ms from the J-point on electrocardiography. The study was powered to detect specificity of ≥91%.

RESULTS

A total of 102 patients were enrolled (65% women, mean age 60 ± 8 years). Thirty-two patients developed ischemia (ischemic group) during EST, whereas 70 patients did not (nonischemic group); both groups were phenotypically similar. Ischemia during EST was 100% specific for CMD. Acetylcholine flow reserve was the strongest predictor of ischemia during exercise. Using endothelium-independent and endothelium-dependent microvascular dysfunction as the reference standard, the false positive rate of EST dropped to 0%.

CONCLUSIONS

In patients with ANOCA, ischemia on EST was highly specific of an underlying ischemic substrate. These findings challenge the traditional belief that EST has a high false positive rate.

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.

Epicardial adipose tissue volume, plaque vulnerability and myocardial ischemia in non-obstructive coronary artery disease

Background

Epicardial adipose tissue (EAT) accumulation has been associated with inflammation, atherosclerosis and microvascular dysfunction. Whether increased EAT volume is associated with coronary plaque vulnerability and demand myocardial ischemia in patients with non-obstructive coronary artery disease (CAD) is less explored.

Methods

In 125 patients (median age 63[58, 69] years and 58% women) with chest pain and non-obstructive CAD, EAT volume was quantified on non-contrast cardiac CT images. EAT volume in the highest tertile (>125 ml) was defined as high EAT volume. Total coronary plaque volume and plaque vulnerability were quantified by coronary CT angiography (CCTA). Demand myocardial ischemia was detected by contrast dobutamine stress echocardiography.

Results

High EAT volume was more common in men and associated with higher BMI, hypertension, increased left ventricular mass index (LVMi), C-reactive protein (CRP) and positive remodelling (all p < 0.05). There was no difference in age, coronary calcium score, total and non-calcified plaque volume or presence of demand myocardial ischemia between groups (all p ≥ 0.34). In a multivariable model, obesity (p = 0.006), hypertension (p = 0.007) and LVMi (p = 0.016) were independently associated with high EAT volume. Including plaque vulnerability in an alternative model, positive remodelling (p = 0.038) was independently associated with high EAT volume.

Conclusion

In non-obstructive CAD, high EAT volume was associated with cardiometabolic risk factors, inflammation and plaque vulnerability, while there was no association with demand myocardial ischemia or coronary plaque volume. Following our results, the role of EAT volume as a biomarker in non-obstructive CAD remains unclear.

Prognostic value of myocardial flow reserve measured with CZT cardiac-dedicated SPECT low-dose dynamic myocardial perfusion imaging in patients with INOCA

BACKGROUND

Clinical use of dynamic myocardial perfusion imaging (D-MPI) of cadmium-zinc-telluride (CZT) cardiac-dedicated SPECT is growing, showing a higher application value than conventional SPECT. The prognostic value of ischemia in patients with non-obstructive coronary arteries (INOCA) remains an important challenge for investigation. The primary objective of this study was to investigate the prognostic value of myocardial flow reserve (MFR) measured with low-dose D-MPI of CZT cardiac-dedicated SPECT in the assessment of patients with INOCA.

METHODS

Consecutive screening of patients with INOCA and obstructive coronary artery disease (OCAD) who had coronary angiography (CAG) data was performed within three months before or after D-MPI imaging. The patients who met the inclusion criteria were retrospectively analyzed and follow-up by telephone was performed. The enrolled patients were then divided into the INOCA and OCAD groups. INOCA was defined as signs and/or symptoms of myocardial ischemia but with < 50% epicardial stenosis. OCAD was defined as obstructive stenosis (≥ 50% stenosis) of epicardial coronary arteries or their major branches on the CAG. Medical treatments, Seattle Angina Questionnaire (SAQ) scores, and major adverse cardiac events (MACEs) were studied. The Kaplan-Meier survival curve, Log-rank test, and univariable COX regression analysis were used to evaluate the prognosis of patients and associated predictors, with P < 0.05 being considered statistically significant.

RESULTS

A total of 303 patients (159 males and 144 females) were enrolled for the final analysis after excluding 24 patients who were lost to follow-up. The mean age of the included cases was 61.94 ± 8.59 years, of which 203 (67.0%) cases were OCAD and 100 (33.0%) cases were INOCA, respectively. The median follow-up was 16 months (14-21 months). Kaplan-Meier survival curves showed that the incidence of MACE was similar in the INOCA and OCAD groups (log-rank P = 0.2645), while those with reduced MFR showed a higher incidence of MACE than those with normal MFR (log-rank P = 0.0019). The subgroup analysis in the OCAD group revealed that 105 patients with reduced MFR had a higher incidence of MACE than those with normal MFR (log-rank P = 0.0226). The subgroup analysis in the INOCA group showed that 37 patients with reduced MFR had a higher incidence of MACE than those with normal MFR in the INOCA group (log-rank P = 0.0186). Univariable Cox regression analysis showed for every 1 unit increase in MFR, the risk of MACE for INOCA was reduced by 66.1% and that for OCAD by 64.2%. For each 1 mL·g-1·min-1 increase in LV-sMBF, the risk of MACE was reduced by 72.4% in INOCA patients and 63.6% in OCAD patients.

CONCLUSIONS

MFR measured with low-dose D-MPI CZT SPECT provides incremental prognostic value in patients with INOCA. Patients with reduced MFR show an increased risk of MACE, increased symptom burdens, and impaired quality of life. INOCA patients with reduced MFR experienced higher rate of MACE than OCAD patients with normal MFR.

#FullPhysiology: a systematic step-by-step guide to implement intracoronary physiology in daily practice

#FullPhysiology is a comprehensive and systematic approach to evaluate patients with suspected coronary disease using PressureWire technology (Abbott Vascular, Santa Clara, CA, USA). This advancement in technology enables the investigation of each component of the coronary circulation, including epicardial, microvascular, and vasomotor function, without significantly increasing procedural time or technical complexity. By identifying the predominant physiopathology responsible for myocardial ischemia, #FullPhysiology enhances precision medicine by providing accurate diagnosis and facilitating tailored interventional or medical treatments. This overview aims to provide insights into modern coronary physiology and describe a systematic approach to assess epicardial flow-limiting disease, longitudinal physiological vessel analysis, microvascular and vasomotor dysfunction, as well as post- percutaneous coronary intervention (PCI) physiological results.

Pharmacotherapy in patients with vasomotor disorders

Background

Anginal symptoms in patients with non-obstructive coronary artery disease are frequently related to vasomotor disorders of the coronary circulation. Although frequently overlooked, a distinct diagnosis of different vasomotor disorders can be made by intracoronary function testing. Early detection and treatment seems beneficial, but little evidence is available for the medical treatment of these disorders. Nevertheless, there are several pharmacotherapeutic options available to treat these patients and improve quality of life.

Methods & findings

We performed an extensive yet non-systematic literature search to explore available pharmacotherapeutic strategies for addressing vasomotor disorders in individuals experiencing angina and non-obstructive coronary artery disease. This article presents a comprehensive overview of therapeutic possibilities for patients exhibiting abnormal vasoconstriction (such as spasm) and abnormal vasodilation (like coronary microvascular dysfunction).

Conclusion

Treatment of vasomotor disorders can be very challenging, but a general treatment algorithm based on the existing evidence and the best available current practice is feasible.

Comprehensive Management of ANOCA, Part 1-Definition, Patient Population, and Diagnosis: JACC State-of-the-Art Review

Angina with nonobstructive coronary arteries (ANOCA) is increasingly recognized and may affect nearly one-half of patients undergoing invasive coronary angiography for suspected ischemic heart disease. This working diagnosis encompasses coronary microvascular dysfunction, microvascular and epicardial spasm, myocardial bridging, and other occult coronary abnormalities. Patients with ANOCA often face a high burden of symptoms and may experience repeated presentations to multiple medical providers before receiving a diagnosis. Given the challenges of establishing a diagnosis, patients with ANOCA frequently experience invalidation and recidivism, possibly leading to anxiety and depression. Advances in scientific knowledge and diagnostic testing now allow for routine evaluation of ANOCA noninvasively and in the cardiac catheterization laboratory with coronary function testing (CFT). CFT includes diagnostic coronary angiography, assessment of coronary flow reserve and microcirculatory resistance, provocative testing for endothelial dysfunction and coronary vasospasm, and intravascular imaging for identification of myocardial bridging, with hemodynamic assessment as needed.

Comprehensive Management of ANOCA, Part 2-Program Development, Treatment, and Research Initiatives: JACC State-of-the-Art Review

Centers specializing in coronary function testing are critical to ensure a systematic approach to the diagnosis and treatment of angina with nonobstructive coronary arteries (ANOCA). Management leveraging lifestyle, pharmacology, and device-based therapeutic options for ANOCA can improve angina burden and quality of life in affected patients. Multidisciplinary care teams that can tailor and titrate therapies based on individual patient needs are critical to the success of comprehensive programs. As coronary function testing for ANOCA is more widely adopted, collaborative research initiatives will be fundamental to improve ANOCA care. These efforts will require standardized symptom assessments and data collection, which will propel future large-scale clinical trials.

Prevalence of angina pectoris and association with coronary atherosclerosis in a general population

OBJECTIVE

To assess the contemporary prevalence of, and factors associated with angina pectoris symptoms, and to examine the relationship to coronary atherosclerosis in a middle-aged, general population.

METHODS

Data were based on the Swedish CArdioPulmonary bioImage Study (SCAPIS), in which 30 154 individuals were randomly recruited from the general population between 2013 and 2018. Participants that completed the Rose Angina Questionnaire were included and categorised as angina or no angina. Subjects with a valid coronary CT angiography (CCTA) were categorised by degree of coronary atherosclerosis; ≥50% obstruction (obstructive coronary atherosclerosis), <50% obstruction or any atheromatosis (non-obstructive coronary atherosclerosis) or none (no coronary atherosclerosis).

RESULTS

The study population consisted of 28 974 questionnaire responders (median age 57.4 years, female 51.6%, hypertension 19.9%, hyperlipidaemia 7.9%, diabetes mellitus 3.7%), of which 1025 (3.5%) fulfilled the criteria of angina. Coronary atherosclerosis was more common in individuals having angina compared with those with no angina (n=24 602, obstructive coronary atherosclerosis 11.8% vs 5.4%, non-obstructive coronary atherosclerosis 38.9% vs 37.0%, no coronary atherosclerosis 49.4% vs 57.7%, all p<0.001). Factors independently associated with angina were birthplace outside of Sweden (OR 2.58 (95% CI 2.10 to 2.92)), low educational level (OR 1.41 (1.10 to 1.79)), unemployment (OR 1.51 (1.27 to 1.81)), poor economic status (OR 1.85 (1.38 to 2.47)), symptoms of depression (OR 1.63 (1.38 to 1.92)) and high degree of stress (OR 2.92 (1.80 to 4.73)).

CONCLUSION

Angina pectoris symptoms are common (3.5%) among middle-aged individuals of the general population of Sweden, though with low association to obstructive coronary atherosclerosis. Sociodemographic and psychological factors are highly associated with angina symptoms, irrespective of degree of coronary atherosclerosis.

Characterization and implications of intracoronary hemodynamic assessment during coronary spasm provocation testing

BACKGROUND

Current diagnostic criteria for coronary spasm are based on patient's symptoms, ECG shifts and epicardial vasoconstriction during acetylcholine (ACh) spasm testing.

AIMS

To assess the feasibility and diagnostic value of coronary blood flow (CBF) and resistance (CR) assessment as objective parameters during ACh testing.

METHODS

Eighty-nine patients who underwent intracoronary reactivity testing including ACh testing with synchronous Doppler wire-based measurements of CBF and CR were included. Coronary microvascular and epicardial spasm, respectively, were diagnosed based on COVADIS criteria.

RESULTS

Patients were 63 ± 13 years old, predominantly female (69%) and had preserved LV ejection fraction (64 ± 8%). Overall, assessment of CBF and CR during ACh testing revealed a decrease in CBF of 0.62 (0.17-1.53)-fold and an increase of CR of 1.45 [0.67-4.02]-fold in spasm patients compared to 2.08 (1.73-4.76) for CBF and 0.45 (0.44-0.63) for CR in patients without coronary spasm (both p < 0.01). Receiver operating characteristic revealed a high diagnostic ability of CBF and CR (AUC 0.86, p < 0.001, respectively) in identifying patients with coronary spasm. However, in 21% of patients with epicardial spasm and 42% of patients with microvascular spasm a paradoxical response was observed.

CONCLUSIONS

This study demonstrates feasibility and potential diagnostic value of intracoronary physiology assessments during ACh testing. We observed opposite responses of CBF and CR to ACh in patients with positive vs. negative spasm test. While a decrease in CBF and an increase in CR during ACh seem pathognomonic for spasm, some patients with coronary spasm demonstrate paradoxical ACh response demanding further scientific investigations.

Echocardiographic assessment of primary microvascular angina and primary coronary microvascular dysfunction

There is an increasing interest in the role of echocardiography in the evaluation of primary microvascular angina, which is attributed to primary coronary microvascular dysfunction. Valid echocardiographic techniques are expected to facilitate the diagnosis and follow-up of these patients and would be valuable for research purposes and therapy evaluation. However, adequate echocardiographic data are lacking, and the interpretation of the limited available literature is hindered by the previous addition of microvascular angina under more inclusive entities, such as cardiac syndrome X. In experienced hands, the assessment of primary coronary microvascular dysfunction in patients with suspected primary microvascular angina, using multiple echocardiographic techniques is feasible, relatively inexpensive, and safe. Exclusion of obstructive epicardial coronary artery disease is, however, a prerequisite for diagnosis. Two-dimensional transthoracic echocardiography, routine stress echocardiography, and speckle-tracking echocardiography indirectly assess primary coronary microvascular dysfunction by evaluating potential impairment in myocardial function and lack diagnostic sensitivity and specificity. Conversely, certain echocardiographic techniques, including Doppler-derived coronary flow velocity reserve and myocardial contrast echocardiography, assess some coronary microvascular dysfunction parameters and have exhibited diagnostic and prognostic potentials. Doppler-derived coronary flow velocity reserve is the best studied and only guideline-approved echocardiographic technique for documenting coronary microvascular dysfunction in patients with suspected microvascular angina. Myocardial contrast echocardiography, by comparison, can detect heterogeneous and patchy myocardial involvement by coronary microvascular dysfunction, which is an advantage over the common practice of coronary flow velocity reserve assessment in a single vessel (commonly the left anterior descending artery) which only reflects regional microvascular function. However, there is no consensus regarding the diagnostic criteria, and expertise performing this technique is limited. Echocardiography remains underexplored and inadequately utilized in the setting of microvascular angina and coronary microvascular dysfunction. Appraisal of the current echocardiographic literature regarding coronary microvascular dysfunction and microvascular angina is important to stay current with the progress in its clinical recognition and create a basis for future research and technological advancements.