Natural History of Patients with Ischemia and No Obstructive Coronary Artery Disease: The CIAO-ISCHEMIA Study

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.

Myocardial ischaemic syndromes: a new nomenclature to harmonize evolving international clinical practice guidelines

Since the 1960s, cardiologists have adopted several binary classification systems for acute myocardial infarction (MI) that facilitated improved patient management. Conversely, for chronic stable manifestations of myocardial ischaemia, various classifications have emerged over time, often with conflicting terminology-e.g. 'stable coronary artery disease' (CAD), 'stable ischaemic heart disease', and 'chronic coronary syndromes' (CCS). While the 2019 European guidelines introduced CCS to impart symmetry with 'acute coronary syndromes' (ACS), the 2023 American guidelines endorsed the alternative term 'chronic coronary disease'. An unintended consequence of these competing classifications is perpetuation of the restrictive terms 'coronary' and 'disease', often connoting only a singular obstructive CAD mechanism. It is now important to advance a more broadly inclusive terminology for both obstructive and non-obstructive causes of angina and myocardial ischaemia that fosters conceptual clarity and unifies dyssynchronous nomenclatures across guidelines. We, therefore, propose a new binary classification of 'acute myocardial ischaemic syndromes' and 'non-acute myocardial ischaemic syndromes', which comprises both obstructive epicardial and non-obstructive pathogenetic mechanisms, including microvascular dysfunction, vasospastic disorders, and non-coronary causes. We herein retain accepted categories of ACS, ST-segment elevation MI, and non-ST-segment elevation MI, as important subsets for which revascularization is of proven clinical benefit, as well as new terms like ischaemia and MI with non-obstructive coronary arteries. Overall, such a more encompassing nomenclature better aligns, unifies, and harmonizes different pathophysiologic causes of myocardial ischaemia and should result in more refined diagnostic and therapeutic approaches targeted to the multiple pathobiological precipitants of angina pectoris, ischaemia and infarction.

Emerging Pathway to a Precision Medicine Approach for Angina With Nonobstructive Coronary Arteries in Women

Women are disproportionately affected by symptoms of angina with nonobstructive coronary arteries (ANOCA) which is associated with significant mortality and economic impact. Although distinct endotypes of ANOCA have been defined, it is underdiagnosed and is often incompletely characterized when identified. Patients are often unresponsive to traditional therapeutic options, which are typically antianginal, and the current ability to guide treatment modification by specific pathways is limited. Studies have associated specific genetic loci, transcriptomic features, and biomarkers with ANOCA. Such panomic data, in combination with known imaging and invasive diagnostic techniques, should be utilized to define more precise pathophysiologic subtypes of ANOCA in women, which will in turn help to identify targeted, effective therapies. A precision medicine-based approach to managing ANOCA incorporating these techniques in women has the potential to significantly improve their clinical care.

Endothelial microRNAs in INOCA patients with diabetes mellitus

Ischemia with non-obstructive coronary artery (INOCA) is a common cause of hospital admissions, leading to negative outcomes and reduced quality of life. Central to its pathophysiology is endothelial dysfunction, which contributes to myocardial ischemia despite the absence of significant coronary artery blockage. Addressing endothelial dysfunction is essential in managing INOCA to alleviate symptoms and prevent cardiovascular events. Recent studies have identified diabetes mellitus (DM) as a significant factor exacerbating INOCA complications by promoting endothelial impairment and coronary microvascular dysfunction. MicroRNAs (miRNAs) have emerged as potential biomarkers and therapeutic targets in various biological processes, including endothelial dysfunction and cardiovascular diseases. However, research on miRNA biomarkers in INOCA patients is sparse. In this study, we examined a panel of circulating miRNAs involved in the regulation of endothelial function in INOCA patients with and without DM. We analyzed miRNA expression using RT-qPCR in a cohort of consecutive INOCA patients undergoing percutaneous coronary intervention. We detected a significant dysregulation of miR-363-5p and miR-92a-3p in INOCA patients with DM compared to those without DM, indicating their role as biomarkers for predicting and monitoring endothelial dysfunction in INOCA patients with DM.

Ischaemia with no obstructive coronary arteries: a review with focus on the Asian population

ABSTRACT

Ischaemia with no obstructive coronary arteries (INOCA) has been a diagnostic and therapeutic challenge for decades. Several studies have demonstrated that INOCA is associated with an increased risk of death, adverse cardiovascular events, poor quality of life and high healthcare cost. Although there is increasing recognition of this entity in the Western population, in the Asian population, INOCA remains elusive and its prevalence uncertain. Despite its prognostic significance, diagnosis of INOCA is often delayed. In this review, we identified the multiple barriers to its diagnosis and management, and proposed strategies to overcome them.

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.

Ischemic Heart Disease in Women

This review synthesizes the current understanding of ischemic heart disease in women, briefly discussing differences in risk factors, presentation, and treatment. We have underscored the unique clinical phenotype of IHD in women with a higher prevalence of ischemia with non-obstructive coronary arteries. Further research is needed to elucidate the complexities of ischemic heart disease in women, understand the discordance between ischemic burden and clinical symptoms, and optimize treatment strategies.

Comparison of risk profiles of participants in the Women's IschemiA TRial to Reduce events In non-ObstRuctive CAD (WARRIOR) trial, using Coronary Computed Tomography Angiography vs Invasive Coronary Angiography

OBJECTIVE

To compare baseline characteristics of participants in the Women's IschemiA TRial to Reduce Events In Non-ObstRuctive CAD (WARRIOR) trial by qualification by Coronary Computed Tomography Angiography (CCTA) or Invasive Coronary Angiography (ICA).

METHODS

The WARRIOR trial (NCT03417388) is an ongoing multicenter, prospective, randomized, blinded outcome evaluation of intensive medical therapy vs. usual care in women with suspected Ischemia and No Obstructive Coronary Artery Disease (INOCA) identified by either CCTA or ICA on the outcome of major adverse cardiovascular events (MACE). No obstructive coronary artery disease is defined as <50% luminal stenosis and normal coronary arteries is defined as no evidence of atherosclerosis including calcified and non-calcified plaque. Data presented was extracted on May 27, 2020. No clinical outcomes were assessed.

RESULTS

An initial sample cohort of 797 women was included. The majority were younger than 65 years, White participants (73.3%), 159 had diabetes (19.9%), and 676 had angina (84.8%) with the remainder having symptoms of suspected ischemic heart disease. Over 50% of randomized participants had normal coronaries without luminal irregularities by ICA or CCTA. Participants randomized to ICA were more likely to have worse baseline clinical risk profiles with older age, higher burden of cardiac risk factors and poor quality of life with disabling angina.

CONCLUSIONS

Among this initial sample of women with suspected INOCA randomized in the WARRIOR trial, there is a differential baseline cardiac risk of participants enrolled after CCTA or ICA. However, the majority had no evidence of atherosclerotic plaque or obstructive stenosis, after evaluation by ICA or CCTA. These results suggest that non-invasive evaluation with CCTA is likely to be associated with lower risk of MACE.

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.

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.

The clinical use of stress echocardiography in chronic coronary syndromes and beyond coronary artery disease: a clinical consensus statement from the European Association of Cardiovascular Imaging of the ESC

Since the 2009 publication of the stress echocardiography expert consensus of the European Association of Echocardiography, and after the 2016 advice of the American Society of Echocardiography-European Association of Cardiovascular Imaging for applications beyond coronary artery disease, new information has become available regarding stress echo. Until recently, the assessment of regional wall motion abnormality was the only universally practiced step of stress echo. In the state-of-the-art ABCDE protocol, regional wall motion abnormality remains the main step A, but at the same time, regional perfusion using ultrasound-contrast agents may be assessed. Diastolic function and pulmonary B-lines are assessed in step B; left ventricular contractile and preload reserve with volumetric echocardiography in step C; Doppler-based coronary flow velocity reserve in the left anterior descending coronary artery in step D; and ECG-based heart rate reserve in non-imaging step E. These five biomarkers converge, conceptually and methodologically, in the ABCDE protocol allowing comprehensive risk stratification of the vulnerable patient with chronic coronary syndromes. The present document summarizes current practice guidelines recommendations and training requirements and harmonizes the clinical guidelines of the European Society of Cardiology in many diverse cardiac conditions, from chronic coronary syndromes to valvular heart disease. The continuous refinement of imaging technology and the diffusion of ultrasound-contrast agents improve image quality, feasibility, and reader accuracy in assessing wall motion and perfusion, left ventricular volumes, and coronary flow velocity. Carotid imaging detects pre-obstructive atherosclerosis and improves risk prediction similarly to coronary atherosclerosis. The revolutionary impact of artificial intelligence on echocardiographic image acquisition and analysis makes stress echo more operator-independent and objective. Stress echo has unique features of low cost, versatility, and universal availability. It does not need ionizing radiation exposure and has near-zero carbon dioxide emissions. Stress echo is a convenient and sustainable choice for functional testing within and beyond coronary artery disease.

Triglyceride glucose-body mass index as a novel predictor of slow coronary flow phenomenon in patients with ischemia and nonobstructive coronary arteries (INOCA)

BACKGROUND

The triglyceride glucose-body mass index (TyG-BMI index) has been suggested as a novel predictor of insulin resistance. However, its predictive value for slow coronary flow phenomenon (SCFP) in patients with ischemia and nonobstructive coronary arteries (INOCA) remains unclear.

METHODS

We consecutively recruited 1625 patients with INOCA from February 2019 to February 2023 and divided them into two groups based on thrombolysis in myocardial infarction (TIMI) frame counts (TFCs): the SCFP group (n = 79) and the control group. A 1:2 age-matched case-control study was then performed. The TyG-BMI index was calculated as ln [plasma triglyceride (mg/dL) × fasting blood glucose (mg/dL)/2] × BMI.

RESULTS

TyG-BMI index in the SCFP group (218.3 ± 25.2 vs 201.0 ± 26.5, P < .001) was significantly higher than in the normal controls. TyG-BMI index also increased with the number of coronary arteries involved in the SCFP. Multivariate logistic regression analysis showed that TyG-BMI, BMI, and TG were independent predictors for SCFP. Receiver operating characteristic (ROC) curve analysis showed that when the TyG-BMI index was above 206.7, the sensitivity and specificity were 88.6% and 68.5%, respectively, with an AUC of 0.809 (95% CI: 0.756-0.863, P = .027). Combined BMI with TG, the TyG-BMI index had a better predictive value for SCFP than BMI and TG (P < .001).

CONCLUSION

The TyG-BMI index was an independent predictor for SCFP in INOCA patients, and it had a better predictive value than BMI and TG.

The diagnostic value of stress echocardiography with limited myocardial ischemia in high-risk patients

BACKGROUND

The diagnostic value of limited myocardial ischemia in DSE is not well known.

OBJECTIVES

We investigated whether myocardial ischemia during dobutamine stress echocardiography (DSE) in 1 apical segment of any of the ventricular walls of the left ventricle relates to the anatomical and functional stenosis of the suppling coronary artery.

METHODS

Our observational, prospective study enrolled 212 patients, symptomatic or asymptomatic, with newly diagnosed limited myocardial ischemia on DSE. Almost 25% of them had already known CAD, while the rest were divided into low-risk and high-risk groups, integrating 1-2 and ≥3 classical cardiovascular risk factors, respectively. After DSE, all patients underwent invasive coronary angiography (ICA) and were followed up for one year. In coronary arteries distributing ischemic area, the calculated stenosis ≥50% and FFR<0.8 were considered anatomically and functionally significant, respectively. In the latter cases, the patients underwent coronary revascularization.

RESULTS

Significant anatomical and functional stenosis of the supplying coronary artery was common among patients with already known CAD (62.5% and 44.5%, respectively) or those without CAD but a high-risk profile (60.2% and 25.6%, respectively). In logistic regression analysis, CAD revascularization was independently determined by an already known CAD, diabetes mellitus, and high-risk profile. During follow-up, 24 patients experienced ACS or new angina episodes, which were associated with diabetes and smoking in univariate analysis.

CONCLUSION

Limited myocardial ischemia may implicate significant anatomical and functional coronary stenosis among individuals with a history of CAD or those without known CAD but a high-risk profile. The prognostic value of our findings requires further investigation.

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.

Global Longitudinal Strain as Predictor of Inducible Ischemia in No Obstructive Coronary Artery Disease in the CIAO-ISCHEMIA Study

BACKGROUND

Global longitudinal strain (GLS) is a sensitive marker for identifying subclinical myocardial dysfunction in obstructive coronary artery disease (CAD). Little is known about the relationship between GLS and ischemia in patients with myocardial ischemia and no obstructive CAD (INOCA).

OBJECTIVES

To investigate the relationship between resting GLS and ischemia on stress echocardiography (SE) in patients with INOCA.

METHODS

Left ventricular GLS was calculated offline on resting SE images at enrollment (n = 144) and 1-year follow-up (n = 120) in the CIAO-ISCHEMIA (Changes in Ischemia and Angina over One year in International Study of Comparative Health Effectiveness with Medical and Invasive Approaches trial screen failures with no obstructive CAD on computed tomography [CT] angiography) study, which enrolled participants with moderate or severe ischemia by local SE interpretation (≥3 segments with new or worsening wall motion abnormality and no obstructive (<50% stenosis) on coronary computed tomography angiography.

RESULTS

Global longitudinal strain values were normal in 83.3% at enrollment and 94.2% at follow-up. Global longitudinal strain values were not associated with a positive SE at enrollment (GLS = -21.5% positive SE vs GLS = -19.9% negative SE, P = .443) or follow-up (GLS = -23.2% positive SE vs GLS = -23.1% negative SE, P = .859). Significant change in GLS was not associated with positive SE in follow-up (P = .401). Regional strain was not associated with colocalizing ischemia at enrollment or follow-up. Changes in GLS and number of ischemic segments from enrollment to follow-up showed a modest but not clinically meaningful correlation (β = 0.41; 95% CI, 0.16, 0.67; P = .002).

CONCLUSIONS

In this cohort of INOCA patients, resting GLS values were largely normal and did not associate with the presence, severity, or location of stress-induced ischemia. These findings may suggest the absence of subclinical myocardial dysfunction detectable by echocardiographic strain analysis at rest in INOCA.

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.

Sex differences in the management of atherosclerotic cardiovascular disease

Disparities between women and men persist in the diagnosis, treatment, and prognosis of atherosclerotic cardiovascular disease (ASCVD). Despite growing attention to sex-based differences in cardiovascular care, there are continued disparities in short- and long-term outcomes. Such disparities highlight the need to identify pathophysiologic differences in treatment patterns for stable ischemic heart disease, non-ST elevation myocardial infarction (NSTE-ACS), ST-elevation myocardial infarction (STEMI), and myocardial infarction with non-obstructive coronary arteries (MINOCA). The role of age as an effect modifier should also be considered given that young women diagnosed with ACS continue to experience increased rates of in-hospital mortality and major adverse cardiovascular events. Both patient-directed and systems-based approaches remain integral to improve outcomes in cardiovascular care. While inadequate representation of women in clinical trials remains a barrier to the implementation of evidence-based therapies, a growing body of data has established the efficacy and safety of medications in women across acute coronary syndromes. This review seeks to feature existing data on the differential treatment guidelines, care implementation, and cardiovascular outcomes between women and men, highlighting next directions for clinical investigation.

Sex differences in coronary artery bypass graft surgery outcomes: a narrative review

Background and Objective

Coronary artery bypass grafting (CABG) is the most commonly performed cardiac surgery globally and in the United States, however, women have worse outcomes than men. We aim to examine the possible drivers of this sex difference in CABG outcomes.

Methods

A narrative review using a current search of the most recent literature on this topic.

Key Content and Findings

The sex difference in outcomes after CABG has persisted despite advances in the field, with women having well-described worse operative mortality and morbidity than men. Several explanatory mechanisms have been proposed for these differences. These include, but are not limited to, preoperative factors such as the natural history of coronary artery disease in women, older age, and higher prevalence of comorbidities at the time of presentation for CABG surgery. Intraoperative factors have also been proposed to play a role, including the smaller coronary artery size and greater coronary artery reactivity in women, the degree of intraoperative hemodilution anemia, the type of grafting, and the completeness of revascularization. However, no definitive etiology has been identified to date.

Conclusions

The sex difference in outcomes after CABG remains present, and despite numerous proposed etiopathologies, the main driver remains unclear. Further research is needed to identify, and address, the root cause of this difference, and greater participation of women in cardiovascular and cardiac surgery trials is crucial.

Symptom Presentation among Women with Suspected Ischemia and No Obstructive Coronary Artery Disease (INOCA)

Identifying ischemic heart disease (IHD) in women based on symptoms is challenging. Women are more likely to endorse non-cardiac symptoms. More than 50% of women with suspected ischemia have no obstructive coronary disease (and thus, INOCA) and impaired outcomes during follow-up. We aimed to identify symptoms having predictive capacity for INOCA in women with clinical evidence of coronary ischemia. We included 916 women from the original WISE cohort (NCT00000554) who had coronary angiography performed for suspected ischemia and completed a 65-item WISE symptom questionnaire. Sixty-two percent (n = 567) had suspected INOCA. Logistic regression models using a best subsets approach were examined to identify the best predictive model for INOCA based on Score χ2 and AICc. A 10-variable, best-fit model accurately predicted INOCA (AUC 0.72, 95% CI 0.68, 0.75). The model indicated that age ≤ 55 years, left side chest pain, chest discomfort, neck pain, and palpitations had independent, positive relationship (OR > 1) to INOCA (p < 0.001 to 0.008). An inverse relationship (OR < 1) was observed for impending doom, and pain in the jaw, left or bilateral arm, and right hand, interpreted as INOCA associated with the absence of these symptoms (p ≤ 0.001 to 0.023). Our best-fit model accurately predicted INOCA based on age and symptom presentation ~72% of the time. While the heterogeneity of symptom presentation limits the utility of this unvalidated 10-variable model, it has promise for consideration of symptom inclusion in future INOCA prediction risk modeling for women with evidence of symptomatic ischemia.

Sex Differences in Quality of Life in Patients with Ischemia with No Obstructive Coronary Artery Disease (INOCA): A Patient Self-Report Retrospective Survey from INOCA International

Women with obstructive coronary artery disease (CAD) have a relatively lower quality of life (QoL) compared to men, but our understanding of sex differences in QoL in ischemia with no obstructive coronary artery disease (INOCA) is limited. We conducted a survey of patient members of INOCA International with an assessment of self-reported health measures. Functional capacity was retrospectively estimated using the Duke Activity Status Index (DASI), assessing levels of activities performed before and after INOCA symptom onset. Of the 1579 patient members, the overall survey completion rate was 21%. Women represented 91% of the respondents. Estimated functional capacity, expressed as metabolic equivalents (METs), was higher before compared to after INOCA diagnosis comparably for both women and men. For every one MET decline in functional capacity, there was a significantly greater decline in QoL for men compared with women in physical health (4.0 ± 1.1 vs. 2.9 ± 0.3 days/month, p < 0.001), mental health (2.4 ± 1.2 vs. 1.8 ± 0.3 days/month, p = 0.001), and social health/recreational activities (4.1 ± 1.0 vs. 2.9 ± 0.3 days/month, p = 0.0001), respectively. In an international survey of patients living with INOCA, despite similar diagnoses, clinical comorbidities, and symptoms, INOCA-related functional capacity declines are associated with a greater adverse impact on QoL in men compared to women.

Illness Perception and the Impact of a Definitive Diagnosis on Women With Ischemia and No Obstructive Coronary Artery Disease: A Qualitative Study

BACKGROUND

Ischemia and no obstructive coronary artery disease (INOCA) disproportionately impacts women, yet the underlying pathologies are often not distinguished, contributing to adverse health care experiences and poor quality of life. Coronary function testing at the time of invasive coronary angiography allows for improved diagnostic accuracy. Despite increased recognition of INOCA and expanding access to testing, data lack on first-person perspectives and the impact of receiving a diagnosis in women with INOCA.

METHODS

From 2020 to 2021, we conducted structured telephone interviews with 2 groups of women with INOCA who underwent invasive coronary angiography (n=29) at Yale New Haven Hospital, New Haven, CT: 1 group underwent coronary function testing (n=20, of whom 18 received a mechanism-based diagnosis) and the other group who did not undergo coronary function testing (n=9). The interviews were analyzed using the constant comparison method by a multidisciplinary team.

RESULTS

The mean age was 59.7 years, and 79% and 3% were non-Hispanic White and non-Hispanic Black, respectively. Through iterative coding, 4 themes emerged and were further separated into subthemes that highlight disease experience aspects to be addressed in patient care: (1) distress from symptoms of uncertain cause: symptom constellation, struggle for sensemaking, emotional toll, threat to personal and professional identity; (2) a long journey to reach a definitive diagnosis: self-advocacy and fortitude, healthcare interactions brought about further uncertainty and trauma, therapeutic alliance, sources of information; (3) establishing a diagnosis enabled a path forward: relief and validation, empowerment; and (4) commitment to promoting awareness and supporting other women: recognition of sex and racial/ethnic disparities, support for other women.

CONCLUSIONS

Insights about how women experience the symptoms of INOCA and their interactions with clinicians and the healthcare system hold powerful lessons for more patient-centered care. A coronary function testing-informed diagnosis greatly influences the healthcare experiences, quality of life, and emotional states of women with INOCA.

A Woman's Heart: Improving Uptake and Awareness of Cardiovascular Screening for Middle-Aged Populations

Mid-life, the years leading up to and following the menopause transition, in women is accompanied by a change in cardiometabolic risk factors, including increases in body weight, changes in body composition, a more insulin-resistant state, and a shift towards a more atherogenic dyslipidemia pattern. Cardiovascular disease (CVD) risk assessment should be performed continually throughout the lifespan, as risk is not stagnant and can change throughout the life course. However, mid-life is a particularly important time for a woman to be evaluated for CVD risk so that appropriate preventive strategies can be implemented. Along with assessing traditional risk factors, ascertainment of a reproductive history is an integral part of a comprehensive CVD risk assessment to recognize unique female-specific or female-predominant factors that modify a woman's risk. When there is uncertainty about CVD risk and the net benefit of preventive pharmacotherapy interventions (such as statins), measuring a coronary artery calcium score can help further refine risk and guide shared decision-making. Additionally, there should be heightened sensitivity around identifying signs and symptoms of ischemic heart disease in women, as these may present differently than in men. Ischemia from coronary microvascular disease and/or vasospasm may be present even without obstructive coronary artery disease and is associated with a heightened risk for major cardiovascular events and reduced quality of life. Therefore, correctly identifying CVD in women and implementing preventive and treatment therapies is paramount. Unfortunately, women are underrepresented in cardiovascular clinical trials, and more data are needed about how to best incorporate novel and emerging risk factors into CVD risk assessment. This review outlines an approach to CVD screening and risk assessment in women using several methods, focusing on the middle-aged population.

Autoimmune rheumatic diseases in women with coronary microvascular dysfunction: a report from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) project

Background

While autoimmune rheumatic diseases (ARDs) have been linked with coronary microvascular dysfunction (CMD), the relationship between ARD and CMD in women with signs and symptoms of ischemia and no obstructive arteries (INOCA) are not well described. We hypothesized that among women with CMD, those with ARD history have greater angina, functional limitations, and myocardial perfusion compromise compared to those without ARD history.

Methods

Women with INOCA and confirmed CMD by invasive coronary function testing were included from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) project (NCT00832702). Seattle Angina Questionnaire (SAQ), Duke Activity Status Index (DASI), and cardiac magnetic resonance myocardial perfusion reserve index (MPRI) were collected at baseline. Chart review was performed to confirm self-reported ARD diagnosis.

Results

Of the 207 women with CMD, 19 (9%) had a confirmed history of ARD. Compared to those without ARD, women with ARD were younger (p = 0.04). In addition, they had lower DASI-estimated metabolic equivalents (p = 0.03) and lower MPRI (p = 0.008) but similar SAQ scores. There was a trend towards increased nocturnal angina and stress-induced angina in those with ARD (p = 0.05 for both). Invasive coronary function variables were not significantly different between groups.

Conclusions

Among women with CMD, women with a history of ARD had lower functional status and worse myocardial perfusion reserve compared to women without ARD. Angina-related health status and invasive coronary function were not significantly different between groups. Further studies are warranted to understand mechanisms contributing to CMD among women with ARDs with INOCA.

Role of plaque imaging for identification of vulnerable patients beyond the stage of myocardial ischemia

Chronic coronary syndrome (CCS) is a progressive disease, which often first manifests as acute coronary syndrome (ACS). Imaging modalities are clinically useful in making decisions about the management of patients with CCS. Accumulating evidence has demonstrated that myocardial ischemia is a surrogate marker for CCS management; however, its ability to predict cardiovascular death or nonfatal myocardial infarction is limited. Herein, we present a review that highlights the latest knowledge available on coronary syndromes and discuss the role and limitations of imaging modalities in the diagnosis and management of patients with coronary artery disease. This review covers the essential aspects of the role of imaging in assessing myocardial ischemia and coronary plaque burden and composition. Furthermore, recent clinical trials on lipid-lowering and anti-inflammatory therapies have been discussed. Additionally, it provides a comprehensive overview of intracoronary and noninvasive cardiovascular imaging modalities and an understanding of ACS and CCS, with a focus on histopathology and pathophysiology.

ANOCA/INOCA/MINOCA: Open artery ischemia

Ischemic heart disease continues to represent a major health threat for death, disability, and poor quality of life as it also consumes enormous health-related resources. For over a century, the major clinical phenotype was taken to be obstructive atherosclerosis involving the larger coronary arteries (e.g., coronary artery disease [CAD]). However, evolving evidence now indicates that nonobstructive CAD is the predominant phenotype. Patients within this phenotype have been termed to have angina with no obstructive CAD (ANOCA), ischemia with no obstructive CAD (INOCA), or myocardial infarction with no obstructive coronary arteries (MINOCA). But as methods to assess cardiomyocyte injury evolve, these phenotypic distinctions have begun to merge, raising concern about their usefulness. Also, considerable evidence has suggested several endotypes that link to potential mechanisms. These include coronary microvascular dysfunction, augmented vasoreactivity (failure to relax appropriately, exaggerated constriction ["spasm"], etc.), nonobstructive atherosclerosis, pre-heart failure with preserved ejection fraction, hypercoagulable states, and several others, alone or in combination. This review summarizes these syndromes and their associated clinical outcomes with an emphasis on potential mechanistic signals. These involve the endothelium, the microvasculature, and cardiomyocyte function. Biomarkers of injury/dysfunction involving these structures are discussed along with a hypothetical construct for management being tested in an ongoing trial.

Stress Hyperglycemia Drives the Risk of Hospitalization for Chest Pain in Patients With Ischemia and Nonobstructive Coronary Arteries (INOCA)

OBJECTIVE

Ischemia with nonobstructive coronary arteries (INOCA) is a prevailing finding in patients with angina. However, the main factors underlying the risk of being rehospitalized for chest pain in patients with INOCA remain mostly unknown.

RESEARCH DESIGN AND METHODS

We evaluated INOCA patients referred to the "Casa di Cura Montevergine" in Mercogliano (Avellino), Italy, from January 2016 to January 2021 for percutaneous coronary intervention (PCI). In these subjects, we assessed the impact of the stress hyperglycemia ratio (SHR), defined as the ratio of mmol/L blood glucose and % HbA1c, on the risk of rehospitalization for chest pain.

RESULTS

A total of 2,874 patients with INOCA successfully completed the study. At the 1-year follow-up, the risk of rehospitalization for chest pain was significantly higher (P < 0.001) in INOCA patients with SHR >1 compared to patients with SHR ≤1. These findings were confirmed by multivariable analyses (adjusting for potential confounders, including age, BMI, blood pressure, heart rate, chronic kidney disease, and cholesterol), propensity score matching, and inverse probability of treatment weighting.

CONCLUSIONS

Our data indicate, to our knowledge for the first time, that SHR on hospital admission significantly and independently increases the risk of rehospitalization for chest pain in INOCA patients.

Ischemia With Nonobstructive Coronary Arteries: Insights From the ISCHEMIA Trial

BACKGROUND

Ischemia with nonobstructive coronary arteries (INOCA) is common clinically, particularly among women, but its prevalence among patients with at least moderate ischemia and the relationship between ischemia severity and non-obstructive atherosclerosis severity are unknown.

OBJECTIVES

The authors investigated predictors of INOCA in enrolled, nonrandomized participants in ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches), sex differences, and the relationship between ischemia and atherosclerosis in patients with INOCA.

METHODS

Core laboratories independently reviewed screening noninvasive stress test results (nuclear imaging, echocardiography, magnetic resonance imaging or nonimaging exercise tolerance testing), and coronary computed tomography angiography (CCTA), blinded to results of the screening test. INOCA was defined as all stenoses <50% on CCTA in a patient with moderate or severe ischemia on stress testing. INOCA patients, who were excluded from randomization, were compared with randomized participants with ≥50% stenosis in ≥1 vessel and moderate or severe ischemia.

RESULTS

Among 3,612 participants with core laboratory-confirmed moderate or severe ischemia and interpretable CCTA, 476 (13%) had INOCA. Patients with INOCA were younger, were predominantly female, and had fewer atherosclerosis risk factors. For each stress testing modality, the extent of ischemia tended to be less among patients with INOCA, particularly with nuclear imaging. There was no significant relationship between severity of ischemia and extent or severity of nonobstructive atherosclerosis on CCTA. On multivariable analysis, female sex was independently associated with INOCA (odds ratio: 4.2 [95% CI: 3.4-5.2]).

CONCLUSIONS

Among participants enrolled in ISCHEMIA with core laboratory-confirmed moderate or severe ischemia, the prevalence of INOCA was 13%. Severity of ischemia was not associated with severity of nonobstructive atherosclerosis. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Sex differences in saphenous vein graft patency: A systematic review and meta-analysis

BACKGROUND

Saphenous vein grafts (SVG) are the most commonly used conduits in coronary artery bypass grafting (CABG). Graft failure is observed in up to 50% of SVG at 10 years after surgery. Whether a difference in SVG patency rates exists between men and women remains unclear.

METHODS

We performed a study-level meta-analysis to evaluate sex-related differences in follow-up patency rates of SVG after CABG. A systematic literature search was conducted to identify studies on CABG that reported follow-up SVG patency rates in men and women. The primary outcome was SVG patency rates by sex at follow-up.

RESULTS

Seventeen studies totaling 8235 patients and 14,781 SVG grafts were included. There was no significant difference in follow-up SVG patency rates between men and women (incidence rate ratio 0.96, 95% confidence interval 0.90-1.03, p = .24), with mean angiographic follow-up of 33.5 months (standard deviation 29.2). Leave-one-out and cumulative analysis were consistent with the main analysis. We concluded that follow-up SVG patency rate is similar between men and women undergoing CABG.

Phenotype-based management of coronary microvascular dysfunction

40-70% of patients undergoing invasive coronary angiography with signs and symptoms of ischemia are found to have no obstructive coronary artery disease (INOCA). When this heterogeneous group undergo coronary function testing, approximately two-thirds have demonstrable coronary microvascular dysfunction (CMD), which is independently associated with adverse prognosis. There are four distinct phenotypes, or subgroups, each with unique pathophysiological mechanisms and responses to therapies. The clinical phenotypes are microvascular angina, vasospastic angina, mixed (microvascular and vasospastic), and non-cardiac symptoms (reclassification as non-INOCA). The Coronary Vasomotor Disorders International Study Group (COVADIS) have proposed standardized criteria for diagnosis. There is growing awareness of these conditions among clinicians and within guidelines. Testing for CMD can be done using invasive or non-invasive modalities. The CorMicA study advocates the concept of 'functional angiography' to guide stratified medical therapy. Therapies broadly fall into two categories: those that modulate cardiovascular risk and those to alleviate angina. Management should be tailored to the individual, with periodic reassessment for efficacy. Phenotype-based management is a worthy endeavor for both patients and clinicians, aligning with the concept of 'precision medicine' to improve prognosis, symptom burden, and quality of life. Here, we present a contemporary approach to the phenotype-based management of patients with INOCA.

Role of different echocardiographic modalities in the assessment of microvascular function in women with ischemia and no obstructive coronary arteries

This review summarizes current knowledge about echocardiographic modalities used to assess microvascular function and left ventricular (LV) systolic function in women with ischemia and no obstructive coronary arteries (INOCA). Although the entire pathophysiological background of this clinical entity still remains elusive, it is primarily linked to microvascular dysfunction which can be assessed by coronary flow velocity reserve. Subtle impairments of LV systolic function in women with INOCA are difficult to assess by interpretation of wall motion abnormalities. LV longitudinal function impairment is considered to be an early marker of subclinical systolic dysfunction and can be assessed by global longitudinal strain quantification.

Peak treadmill exercise echocardiography for ischemia detection

Of the stress echocardiographic methods, exercise should be the first choice for patients able to exercise, according to guidelines. Among ExE modalities, treadmill ExE with acquisition of images at peak exercise has several advantages, including high sensitivity and prognostic value. Overall, sensitivity of ExE is around 80%-85%, although figures for peak imaging on the treadmill are 85%-90%. Despite it, guidelines do not mention this method.

Clinical Relevance of Ischemia with Nonobstructive Coronary Arteries According to Coronary Microvascular Dysfunction

Background

In the absence of obstructive coronary stenoses, abnormality of noninvasive stress tests (NIT) in patients with chronic coronary syndromes may indicate myocardial ischemia of nonobstructive coronary arteries (INOCA). The differential prognosis of INOCA according to the presence of coronary microvascular dysfunction (CMD) and incremental prognostic value of CMD with intracoronary physiologic assessment on top of NIT information remains unknown.

Methods and Results

From the international multicenter registry of intracoronary physiologic assessment (ILIAS [Inclusive Invasive Physiological Assessment in Angina Syndromes] registry, N=2322), stable patients with NIT and nonobstructive coronary stenoses with fractional flow reserve >0.80 were selected. INOCA was diagnosed when patients showed positive NIT results. CMD was defined as coronary flow reserve ≤2.5. According to the presence of INOCA and CMD, patients were classified into 4 groups: group 1 (no INOCA nor CMD, n=116); group 2 (only CMD, n=90); group 3 (only INOCA, n=41); and group 4 (both INOCA and CMD, n=40). The primary outcome was major adverse cardiovascular events, a composite of all‐cause death, target vessel myocardial infarction, or clinically driven target vessel revascularization at 5 years. Among 287 patients with nonobstructive coronary stenoses (fractional flow reserve=0.91±0.06), 81 patients (38.2%) were diagnosed with INOCA based on positive NIT. By intracoronary physiologic assessment, 130 patients (45.3%) had CMD. Regardless of the presence of INOCA, patients with CMD showed a significantly lower coronary flow reserve and higher hyperemic microvascular resistance compared with patients without CMD (P<0.001 for all). The cumulative incidence of major adverse cardiovascular events at 5 years were 7.4%, 21.3%, 7.7%, and 34.4% in groups 1 to 4. By documenting CMD (groups 2 and 4), intracoronary physiologic assessment identified patients at a significantly higher risk of major adverse cardiovascular events at 5 years compared with group 1 (group 2: adjusted hazard ratio [HR_adjusted], 2.88; 95% CI, 1.52–7.19; P=0.024; group 4: HR_adjusted, 4.00; 95% CI, 1.41–11.35; P=0.009).

Conclusions

In stable patients with nonobstructive coronary stenoses, a diagnosis of INOCA based only on abnormal NIT did not identify patients with higher risk of long‐term cardiovascular events. Incorporating intracoronary physiologic assessment to NIT information in patients with nonobstructive disease allowed identification of patient subgroups with up to 4‐fold difference in long‐term cardiovascular events.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04485234.

Are we any WISER yet? Progress and contemporary need for smart trials to include women in coronary artery disease trials

Despite calls to ensure proportionate representation of both sexes in biomedical research, women continue to be underrepresented in cardiovascular disease (CVD) clinical trials. A comprehensive analysis of seven large suspected ischemic heart disease/coronary artery disease (HD/CAD) clinical trials (PROMISE, ISCHEMIA, CIAO-ISCHEMIA, ORBITA, FAME, FAME 2 and COURAGE trial) provides understanding of contributions to barriers to enrollment of women and leads to strategies to address these barriers. Specifically, in the seven trials, enrollment of women did not exceed 27%, while numerous barriers are evident. Proposed strategies to improve women´s inclusion in clinical trials, include adding reproductive stage/estrogen status, attention to study design inclusion/exclusion criteria using female thresholds, consideration of diagnostic and intervention study design to be inclusive, increasing women and minorities in leadership positions, including sex as a biological variable (SABV) in study design and statistical analysis, and addressing social and race/ethnicity barriers. Dedicated action to actualizing these steps are needed at this time to developing diagnostic and therapeutic strategies resulting in better care and improved outcomes for CVD in women.

Sex-Related Outcomes of Medical, Percutaneous, and Surgical Interventions for Coronary Artery Disease: JACC Focus Seminar 3/7

Biological and sociocultural differences between men and women are complex and likely account for most of the variations in the epidemiology and treatment outcomes of coronary artery disease (CAD) between the 2 sexes. Worse outcomes in women have been described following both conservative and invasive treatments of CAD. For example, increased levels of residual platelet reactivity during treatment with antiplatelet drugs, higher rates of adverse cardiovascular outcomes following percutaneous coronary revascularization, and higher operative and long-term mortality after coronary bypass surgery have been reported in women compared with in men. Despite the growing recognition of sex-specific determinants of outcomes, representation of women in clinical studies remains low and sex-specific management strategies are generally not provided in guidelines. This review summarizes the current evidence on sex-related differences in patients with CAD, focusing on the differential outcomes following medical therapy, percutaneous coronary interventions, and coronary artery bypass surgery.

Stress Perfusion Cardiac Magnetic Resonance in Long-Standing Non-Infarcted Chronic Coronary Syndrome with Preserved Systolic Function

(1) Background: The impact of imaging-derived ischemia is still under debate and the role of stress perfusion cardiac magnetic resonance (spCMR) in non-high-risk patient still needs to be clarified. The aim of this study was to evaluate the impact of spCMR in a case series of stable long-standing chronic coronary syndrome (CCS) patients with ischemia and no other risk factor. (2) Methods: This is a historical prospective study including 35 patients with history of long-standing CCS who underwent coronary CT angiography (CCTA) and additional adenosine spCMR. Clinical and imaging findings were included in the analysis. Primary outcomes were HF (heart failure) and all major cardiac events (MACE) including death from cardiovascular causes, myocardial infarction, or hospitalization for unstable angina, or resuscitated cardiac arrest. (3) Results: Mean follow-up was 3.7 years (IQR: from 1 to 6). Mean ejection fraction was 61 ± 8%. Twelve patients (31%) referred primary outcomes. Probability of experiencing primary outcomes based on symptoms was 62% and increased to 67% and 91% when multivessel disease and ischemia, respectively, were considered. Higher ischemic burden was predictive of disease progression (OR: 1.59, 95%CI: 1.18–2.14; p-value = 0.002). spCMR model resulted non inferior to the model comprising all variables (4) Conclusions: In vivo spCMR-modeling including perfusion and strain anomalies could represent a powerful tool in long-standing CCS, even when conventional imaging predictors are missing.

Cardiovascular Imaging for Ischemic Heart Disease in Women: Time for a Paradigm Shift

Heart disease is the leading cause of death among men and women. Women have a unique phenotype of ischemic heart disease with less calcified lesions, more nonobstructive plaques, and a higher prevalence of microvascular disease compared with men, which may explain in part why current risk models to detect obstructive coronary artery disease (CAD) may not work as well in women. This paper summarizes the sex differences in the functional and anatomical assessment of CAD in women presenting with stable chest pain and provides an approach for using multimodality imaging for the evaluation of suspected ischemic heart disease in women in accordance to the recently published American Heart Association/American College of Cardiology guidelines for the evaluation and diagnosis of chest pain. A paradigm shift in the approach to imaging ischemic heart disease women is needed including updated risk models, a more profound understanding of CAD in women where nonobstructive disease is more prevalent, and algorithms focused on the evaluation of ischemia with nonobstructive CAD and myocardial infarction with nonobstructive CAD.

Cardiac CT angiography in current practice: An American society for preventive cardiology clinical practice statement✰

In this clinical practice statement, we represent a summary of the current evidence and clinical applications of cardiac computed tomography (CT) in evaluation of coronary artery disease (CAD), from an expert panel organized by the American Society for Preventive Cardiology (ASPC), and appraises the current use and indications of cardiac CT in clinical practice. Cardiac CT is emerging as a front line non-invasive diagnostic test for CAD, with evidence supporting the clinical utility of cardiac CT in diagnosis and prevention. CCTA offers several advantages beyond other testing modalities, due to its ability to identify and characterize coronary stenosis severity and pathophysiological changes in coronary atherosclerosis and stenosis, aiding in early diagnosis, prognosis and management of CAD. This document further explores the emerging applications of CCTA based on functional assessment using CT derived fractional flow reserve, peri‑coronary inflammation and artificial intelligence (AI) that can provide personalized risk assessment and guide targeted treatment. We sought to provide an expert consensus based on the latest evidence and best available clinical practice guidelines regarding the role of CCTA as an essential tool in cardiovascular prevention - applicable to risk assessment and early diagnosis and management, noting potential areas for future investigation.

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.

FT4/FT3 ratio: A novel biomarker predicts coronary microvascular dysfunction (CMD) in euthyroid INOCA patients

BACKGROUND

Ischemia and no obstructive coronary artery disease (INOCA) patients who presented coronary microvascular dysfunction (CMD) demonstrate a poor prognosis, yet the risk factors for CMD remain unclear. Subtle changes in thyroid hormone levels within the normal range, especially the free thyroxine (FT4)/free triiodothyronine (FT3) ratio, have been shown to regulate the cardiovascular system. This prospective study investigated the correlation between FT4/FT3 ratio and CMD in euthyroid patients with INOCA.

METHODS

This prospective study (www.chictr.org.cn/, ChiCTR2000037112) recruited patients with myocardial ischemia symptoms who underwent both coronary angiography (CAG) and myocardial perfusion imaging (MPI) with dynamic single-photon emission computed tomography (D-SPECT). INOCA was defined as coronary stenosis< 50% and CMD was defined as coronary flow reserve (CFR)<2.5. All patients were excluded from abnormal thyroid function and thyroid disease history.

RESULTS

Among 71 INOCA patients (15 [21.1%] CMD), FT4 and FT4/FT3 ratio in CMD group were significantly higher and both showed significantly moderate correlation with CFR (r=-0.25, p=0.03; r=-0.34, p=0.003, respectively). The ROC curve revealed that FT4/FT3 ratio had the highest efficacy for predicting CMD with an optimized cutoff value>3.39 (AUC 0.78, p<0.001, sensitivity, 80.0%; specificity, 71.4%). Multivariate logistic regression showed that FT4/FT3 ratio was an independent predictor of CMD (OR 7.62, 95% CI 1.12-51.89, p=0.038, P for trend=0.006).

CONCLUSION

In euthyroid INOCA patients, increased FT4/FT3 ratio levels are associated with the occurrence of CMD, presenting a novel biomarker for improving the risk stratification.

Gender-Related Differences in Chest Pain Syndromes in the Frontiers in CV Medicine Special Issue: Sex & Gender in CV Medicine

Coronary artery disease (CAD) is the leading cause of morbidity and mortality among both women and men, yet women continue to have delays in diagnosis and treatment. The lack of recognition of sex-specific biological and socio-cultural gender-related differences in chest pain presentation of CAD may, in part, explain these disparities. Sex and gender differences in pain mechanisms including psychological susceptibility, the autonomic nervous system (ANS) reactivity, and visceral innervation likely contribute to chest pain differences. CAD risk scores and typical/atypical angina characterization no longer appear relevant and should not be used in women and men. Women more often have ischemia with no obstructive CAD (INOCA) and myocardial infarction, contributing to diagnostic and therapeutic equipoise. Existing knowledge demonstrates that chest pain often does not relate to obstructive CAD, suggesting a more thoughtful approach to percutaneous coronary intervention (PCI) and medical therapy for chest pain in stable obstructive CAD. Emerging knowledge regarding the central and ANS and visceral pain processing in patients with and without angina offers explanatory mechanisms for chest pain and should be investigated with interdisciplinary teams of cardiologists, neuroscientists, bio-behavioral experts, and pain specialists. Improved understanding of sex and gender differences in chest pain, including biological pathways as well as sociocultural contributions, is needed to improve clinical care in both women and men.