Non-obstructive Coronary Disease Research Articles

SEX DIFFERENCES IN THE CORONARY SYSTEM OF THE HUMAN HEART

The aim of this study is to investigate sex differences in the coronary system of the heart, considering all relevant consequence, and to compile and analyze the gathered data. Materials and Methods. The authors independently conducted a literature search and selection process using the PubMed database for the review, followed by the generalization of the obtained data. Results. Women exhibit a higher propensity than men for certain cardiovascular diseases, including persistent angina, non-obstructive coronary heart disease, coronary microvascular dysfunction, spontaneous coronary artery dissection, stress cardiomyopathy, and heart failure with preserved ejection fraction (HFpEF). In comparison to men, women typically present with elevated rates of underlying comorbidities, encompassing not only advanced age but also hypertension, diabetes mellitus, obesity, chronic renal failure, peripheral vascular disease, HFpEF, and inflammatory conditions like rheumatoid arthritis. Many of these conditions are linked to diffuse atherosclerosis and microvascular ischemia, with notable parallels between non-obstructive coronary heart disease and coronary microvascular dysfunction. Special attention is paid to patients sharing an increased risk of coronary heart disease events, which is consistent between women and men, except for those with severe coronary flow reserve (CFR) impairment, where women demonstrate an even higher risk. In particular, in cases where CFR impairment is not attributable to obstructive coronary heart disease (precluding revascularization to mitigate cardiovascular risk), there may be justification for a novel therapeutic approach for systemic coronary heart disease management. Cases of severe coronary microvascular dysfunction, often concurrent with non-obstructive coronary heart disease, may indicate a shared mechanism influencing coronary heart disease risk in both genders. This mechanism might involve inflammation, endothelial dysfunction, and heightened cardiomyocyte oxygen demand, culminating in microvascular ischemia, myocardial injury, and compromised cardiac function. Conclusions. Enhanced comprehension of the interplay between coronary vasomotor dysfunction and the concomitance of coronary heart disease with other conditions, such as insulin resistance and heart failure, could foster the advancement of novel systemic treatments aimed at leveraging “complete revascularization” more effectively.

Comparing planned versus ad hoc coronary microvascular assessment: Early findings from the Coronary Microvascular Disease Registry

BackgroundCoronary microvascular dysfunction (CMD) is an etiology for angina with non-obstructive coronary disease. However, the initial adoption of CMD assessment, whether planned or conducted ad hoc, is limited. We characterize planned and ad hoc CMD assessments and highlight evolving trends of a CMD referral center. MethodsWe analyzed outpatient data from the Coronary Microvascular Disease Registry from 2021 to 2023. Patients were categorized into planned or ad hoc CMD assessment groups, and baseline characteristics, hospital stay, medications, and physiological measurements were compared. Secondary analysis evaluated a CMD referral center's evolution. ResultsOf 101 included outpatients, 67.3 % underwent ad hoc procedures and 32.7 % planned procedures. Average age was 63.1 ± 10.1 years. The planned procedure group was 87.9 % female, and the ad hoc procedure group was 51.5 % female. There were no significant differences in index of microvascular resistance or coronary flow reserve between groups. Hospital stay duration was <1 day for both groups, and neither reported complications. Ad hoc patients were more frequently prescribed aspirin before (64.7 % vs. 36.4 %, p = 0.007) and after the procedure (66.2 % vs. 39.4 %, p = 0.01). CMD rates were higher for planned procedures (30.3 % vs. 10.3 %, p = 0.01). We observed that CMD referral centers have more planned procedures and a higher rate of positive results over time. ConclusionCMD referral centers' planned procedures, and subsequent positive cases, increased over time. This emphasizes the importance of planned procedures, appropriate patient selection, and increased awareness of CMD among healthcare providers. Clinical trial registrationCoronary Microvascular Disease (CMD) Registry, NCT05960474, https://clinicaltrials.gov/study/NCT05960474

Establishment of nonobstructive coronary microcirculatory disorders in rabbits using three established methods and a comparative study

To compare the merits and drawbacks of three approaches for establishing a rabbit model of nonobstructive coronary microcirculatory disease, namely, open thoracic subtotal ligation of coronary arteries, ultrasound-guided cardiac microsphere injection, and sodium laurate injection. New Zealand rabbits were allocated to four groups: a normal group (Blank group), an Open-chest group (Open-chest), a microsphere group (Echo-M), and a sodium laurate group (Echo-SL), each comprising 10 rabbits. The rabbits were sacrificed 24 h after the procedures, and their echocardiography, stress myocardial contrast echocardiography, pathology, and surgical times were compared. The results demonstrated varying degrees of reduced cardiac function in all three experimental groups, the Open-chest group exhibiting the most significant decline. The myocardial filling in the affected areas was visually analyzed by myocardial contrast echocardiography, revealing sparse filling at rest but more after stress. Quantitative analysis of perfusion parameters (β, A, MBF) in the affected myocardium showed reduced values, the Open-chest group having the most severe reductions. No differences were observed in stress myocardial acoustic imaging parameters between the Echo-M and Echo-SL groups. Among the pathological presentations, the Open-chest model predominantly exhibited localized ischemia, while the Echo-M model was characterized by mechanical physical embolism, and the Echo-SL model displayed in situ thrombosis as the primary pathological feature. Inflammatory responses and collagen deposition were observed in all groups, with the severity ranking of Open-chest > Echo-SL > Echo-M. The ultrasound-guided intracardiac injection method used in this experiment outperformed open-chest surgery in terms of procedural efficiency, invasiveness, and maneuverability. This study not only optimizes established cardiac injection techniques but also offers valuable evidence to support clinical investigations through a comparison of various modeling methods.

Men with nonobstructive coronary disease have higher burden of ischemic heart disease detected by cardiopulmonary exercise test.

Nonobstructive coronary artery disease (NOCAD), characterized by the presence of myocardial ischemic symptoms and signs without obstructive coronaries, is a common clinical condition, but it is less well understood. Few studies have analyzed the gender differences in inducible myocardial ischemia assessed by cardiopulmonary exercise test (CPET) in NOCAD. We conducted a study of 289 NOCAD patients (mean age 60, 56% women) with ischemic symptoms and confirmed ⫹50% coronaries stenoses by coronary angiography who underwent symptom-limited CPET. We assessed ischemic response using predicted % peak VO2 , O2 pulse trajectory, and exercise ECG test. Men with NOCAD had significantly lower predicted % peak VO2 (62% vs. 73%), higher proportions of flattening pattern (16% vs. 2%), and downward patterns of O2 pulse trajectory (2% vs. 0%) (p < .0001) compared with women. In contrast, women with NOCAD had a higher prevalence of shallow patterns of O2 pulse trajectory (21% vs. 6%, p < .0001). Men with NOCAD had a higher risk ischemic profile (medium risk: 63% vs. 54%, high risk: 18% vs. 4%, p < .0001). After adjustment, men with NOCAD had significantly lower predicted % peak VO2 (β -27.4, 95% CI -30.74 to -24.07), higher risk for abnormal O2 pulse trajectories (OR 4.21, 95% CI 1.93 to 9.19), and myocardial ischemia risk per CPET parameters (OR 3.14, 95% CI 1.78 to 5.54) (p < .0001). Men with NOCAD had a higher risk profile for ischemic heart disease per CPET. Therefore, they should receive rigorous management and follow-up to prevent cardiovascular events.

A Randomized Controlled Study of Enhanced External Counterpulsation with Cardiac Rehabilitation in Patients with Nonobstructive Coronary Artery Disease and Coronary Microvascular Dysfunction.

Treatment with enhanced external counterpulsation (EECP) or cardiac rehabilitation (CR) benefits patients with coronary heart disease; this paper intends to explore the feasibility of EECP combined with CR in patients with nonobstructive coronary heart disease (NOCAD) and coronary microcirculation disorders (CMD).In January 2021-2022 month June our income NOCAD patients as the research object, the line of cardiac magnetic resonance (CMR), myocardial perfusion reserve (MPR) < 2.0 coronary microcirculation disorders (CMD, 80 cases). Random indicator method 80 CMD patients divided into two groups, 40 cases in each. Usual treatment group: conventional drugs and CR therapy. EECP treatment group: on the basis of standard treatment group, employ EECP therapy. Comparing the two groups before and after the treatment curative effect cardiac function index, endothelial unction index, adverse cardiovascular events, etc.After EECP treatment, the treatment group showed a higher effective rate compared to the usual treatment group (P < 0.05). EECP group curative effect, left ventricular ejection fraction,plasma NO and vascular endothelial growth factor levels higher than the usual group, the incidence of adverse cardiovascular events is lower than the usual group. The difference was statistically significant (P < 0.05).EECP combined with cardiac rehabilitation in patients with CMD symptoms has better effect and safety and provides reference for treatment of CMD patients.

Coronary Tortuosity Index vs. Angle Measurement Method for the Quantification of the Tortuosity of Coronary Arteries in Non-Obstructive Coronary Disease.

Coronary tortuosity has been recognized as a potential pathophysiological mechanism in the development of non-obstructive coronary artery disease (CAD). The aim of this study was to examine the role of two coronary tortuosity measurement methods in the detection of clinically significant coronary tortuosity. The study included 160 patients with angina symptoms and myocardial ischemia detected by cardiac stress tests in chronic settings and those diagnosed with acute coronary syndrome. After coronary angiography, tortuosity of coronary arteries was assessed by two methods, including measurement of tortuosity angles and calculating of tortuosity index. Significantly more tortuous coronary arteries were detected in the group with non-obstructive CAD (p < 0.01 for all three arteries), with significantly higher tortuosity index (TI) for all three coronary arteries in this group of patients, compared to patients with obstructive CAD. The highest TI for LCX was found in patients with lateral ischemia (p < 0.001) and for LAD in patients with anterior ischemia (p < 0.001). When measured by the angle method, the only association was found between LCX tortuosity and lateral ischemia (OR 4.9, p = 0.046). In conclusion, coronary tortuosity represents a pathophysiological mechanism for myocardial ischemia in non-obstructive CAD. The coronary tortuosity index could be a reliable and widely applicable tool for the quantification of coronary tortuosity.

Men with non-obstructive coronary disease have higher risk of exercise-induced myocardial ischemia detected by cardiopulmonary exercise test

Abstract Background Non-obstructive coronary artery disease (NOCAD) had similar morbidity and mortality as patients with obstructive coronary artery disease but less understood. Limited studies analyzed the gender differences in inducible myocardial ischemia assessed by cardiopulmonary exercise test (CPET) in NOCAD. Methods A total of 289 NOCAD patients (mean age 60, 56% women) who had ischemic symptoms and ⫹ 50% coronaries stenoses confirmed by coronary angiography performed the symptom-limited CPET. We used the predicted % peak VO2, O2 pulse trajectory, and exercise ECG test to assess inducible myocardial ischemia. Results Compared with women, men with NOCAD had significantly lower predicted % peak VO2 (62% vs. 73%), higher proportions of flattening pattern (16% vs. 2%) and downward pattern of O2 pulse trajectory (2% vs. 0%) (P &amp;lt; 0.0001). Instead, women with NOCAD had higher prevalence of shallow pattern of O2 pulse trajectory (21% vs. 6%, P &amp;lt; 0.0001). Men with NOCAD had higher proportions of increased risk of exercise-induced myocardial ischemia (medium risk: 63% vs. 54%, high risk: 18% vs. 4%, P &amp;lt; 0.0001). After adjustment, men with NOCAD demonstrated significantly lower predicted % peak VO2 (β -27.4, 95% CI -30.74 – -24.07), higher risk for abnormal O2 pulse trajectories (OR 4.21, 95% CI 1.93 – 9.19) and myocardial ischemia risk detected by CPET (OR 3.14, 95% CI 1.78 – 5.54) (P &amp;lt; 0.0001). Conclusion Men with NOCAD had higher risk of exercise-induced myocardial ischemia detected by CPET that should be given rigorous management and follow-up to prevent cardiovascular events.

Abstract 18268: Angina and Functional Capacity Among Women Presenting With Angina and Non-Obstructive Coronary Disease

Introduction: Approximately 75% of women that undergo coronary angiography for angina do not have obstructive disease. However, a significant number have persistent angina, which can reduce their functional capacity and performance, impacting patients’ quality of life. There is a need for further studies that accurately compare angina and functional capacity among women angina with non-obstructive coronary disease (ANOCA). Objective: We examined the association between perceived anginal symptoms and functional capacity in patients with ANOCA Methods: A the Women’s Heart Center at the Christ Hospital, all women completed the Duke Activity Status Index (DASI) and Seattle Angina Questionnaire-7 (SAQ7) at the initial visit. DASI score range from 0 to 58.2 and assess functional capacity using self-assessment and VO2 peak formula with higher scores indicating better functional capacity. SAQ7 assesses angina symptoms, physical limitation, and quality of life; the score is from 0-100, where a lower score indicates a higher frequency of angina, increased physical limitation, and poor quality of life. DASI and SAQ7 scores were correlated. Sperman correlation and Mcnemar chi-square were used to compare DASI and SAQ7 score results. Results: Among 225 women with ANOCA, the mean DASI score was 16.73, and the mean SAQ7 score was 43.79. 63.1% reported a low score of SAQ7, and 79.6% reported a low DASI score. SAQ7 and DASI were moderately correlated (Spearman correlation of +0.42). Further analysis with McNemar chi- square showed that women with lower SAQ7 (score 0-49.4) tends to corresponds with low DASI (score 0-24.5) (Specificity 86.6%), compared to women with higher SAQ7 (score 49.5-100) and high DASI (score 24.6-58.2) (Sensitivity 32.5%) (p&lt;0.001). Discussion: Anginal symptoms are correlated with reduced functional capacity among women with ANOCA. Further prospective studies are needed to evaluate the correlation between angina improvement and functional capacity.

Progression of non-obstructive coronary plaque: a practical CCTA-based risk score from the PARADIGM registry.

No clear recommendations are endorsed by the different scientific societies on the clinical use of repeat coronary computed tomography angiography (CCTA) in patients with non-obstructive coronary artery disease (CAD). This study aimed to develop and validate a practical CCTA risk score to predict medium-term disease progression in patients at a low-to-intermediate probability of CAD. Patients were part of the Progression of AtheRosclerotic PlAque Determined by Computed Tomographic Angiography Imaging (PARADIGM) registry. Specifically, 370 (derivation cohort) and 219 (validation cohort) patients with two repeat, clinically indicated CCTA scans, non-obstructive CAD, and absence of high-risk plaque (≥ 2 high-risk features) at baseline CCTA were included. Disease progression was defined as the new occurrence of ≥ 50% stenosis and/or high-risk plaque at follow-up CCTA. In the derivation cohort, 104 (28%) patients experienced disease progression. The median time interval between the two CCTAs was 3.3years (2.7-4.8). Odds ratios for disease progression derived from multivariable logistic regression were as follows: 4.59 (95% confidence interval: 1.69-12.48) for the number of plaques with spotty calcification, 3.73 (1.46-9.52) for the number of plaques with low attenuation component, 2.71 (1.62-4.50) for 25-49% stenosis severity, 1.47 (1.17-1.84) for the number of bifurcation plaques, and 1.21 (1.02-1.42) for the time between the two CCTAs. The C-statistics of the model were 0.732 (0.676-0.788) and 0.668 (0.583-0.752) in the derivation and validation cohorts, respectively. The new CCTA-based risk score is a simple and practical tool that can predict mid-term CAD progression in patients with known non-obstructive CAD. The clinical implementation of this new CCTA-based risk score can help promote the management of patients with non-obstructive coronary disease in terms of timing of imaging follow-up and therapeutic strategies. • No recommendations are available on the use of repeat CCTA in patients with non-obstructive CAD. • This new CCTA score predicts mid-term CAD progression in patients with non-obstructive stenosis at baseline. • This new CCTA score can help guide the clinical management of patients with non-obstructive CAD.

Occult myocardial injury is prevalent amongst elderly patients in the hospital-at-home setting. A retrospective analysis of 213 patients

BackgroundHospital-at-Home (HAH) is a valid alternative for in-hospital stay for a wide variety of clinical indications. Occult myocardial injury, associated with acute illness, mainly occurs in patients with a background of non-obstructive coronary disease. The aim of this study was to describe the prevalence of this phenomenon in our HAH population. MethodsA retrospective description and analysis of data collected for patients admitted to the Sheba beyond's HAH services during 14 months. ResultsDuring a period of 14 months (7/10/21–6/12/22), blood troponin measurements were available for 213 patients (median age 78 years, 52% males) hospitalized mainly for infectious causes. The median HS (highly sensitive) troponin level was 7.7 ng/L (IQR = 13.2 ng/L) (the normal upper limit is 12 ng/L) with 31% of all patients demonstrating an abnormally increased troponin level (68/213). Of all patients, 64% had a background diagnosis of a cardiovascular disease (138/213), of whom, 49% had abnormal HS troponin levels (68/138). No patient suffered from acute cardiac function deterioration and no patient died during their hospital-at-home stay. ConclusionThe prevalence of occult myocardial injury amongst elderly patients admitted to hospital-at-home stay for diagnoses other than myocardial infarction is relatively high but it is not associated with worse short-term clinical outcomes.

Acute Myocardial Infarction in Young Individuals: Demographic and Risk Factor Profile, Clinical Features, Angiographic Findings and In-Hospital Outcome.

Cardiovascular diseases (CVDs) are the leading cause of global mortality and disability. Acute myocardial infarction (AMI) in young individuals is a rare condition but can cause devastating socioeconomic and psychological consequences for both the patient and their family and an economic burden for the government. There is a paucity of data concerning the specific profile of these young patients in Bulgaria, a country with a high burden of cardiovascular morbidity and mortality. Therefore, the aim of the present study was to assess the baseline characteristics, demographic and risk factor profile, clinical features, angiographic findings and in-hospital outcomes of young patients with AMI. Additionally, these data were compared to those of the older age group. Retrospective data on 172 patients treated for AMI in "Prof. Alexandar Tschirkov", Bulgaria, from January 2018 to December 2021 were collected for the purpose of this study. Baseline characteristics, risk factor profileand clinical and angiographic features were compared in young (≤45 years) and older patients (>45 years). Males were significantly predominant in the two age groups (p < 0.01), with an obviously increasing proportion of females in the older age group. Young patients were more likely to be smokers (55.7% vs. 28.8%; p=0.001); in contrast, hypertension (70.5% vs. 91.9%; p <0.001) and obesity (16.4% vs. 31.5%; p=0.031) were more prevalent in older patients. Anterior localization of myocardial infarction (MI) wasmost common in the two age groups (47.5% vs. 41.4%), respectively. Regarding the time delay from symptom onset to first medical contact, we found that young patients tended to present earlier than their older counterparts. Young patients had a higher incidence of single vessel disease (SVD) (49.2%) and nonobstructive coronary disease (NOCD) (11.5%) than older patients. Young patients with AMI had a lower in-hospital morbidity rate than older patients, but the in-hospital mortality, although lower, was not significantly different. A high prevalence of modifiable cardiovascular risk factors (RFs), such as smoking, dyslipidemia and arterial hypertension (AH), among the young group, less evolved CADand similar high procedural success between age groups were established. Approximately 30% of young patients tend to present late in the hospital. The in-hospital mortality in the young population was lower than that in the older population but was still relatively higher than that previously reported. The reported high prevalence of modifiable RFs and late presentation of young patients with AMI highlight the need for early recognition of these RFs, better prevention, deployment of educational programs, easy access to health care and high awareness of clinicians to reduce disability and mortality from CVD.

Particularities of coronary physiology in patients with atrial fibrillation: insights from combined pressure and flow indices measurements.

Symptoms suggestive of myocardial ischemia are frequently encountered in patients with atrial fibrillation (AF) even in the absence of obstructive coronary artery disease. Nevertheless, an in-depth characterisation of coronary physiology in patients with AF is currently lacking. We aim to provide an insight into the characteristics of coronary physiology in AF, by performing simultaneous invasive measurements of coronary flow- and pressure- indices in a real-life population of patients with AF and indication of coronary angiography. This is a prospective open label study including patients with permanent or persistent AF and indication of coronary angiography showing intermediate coronary stenosis requiring routine physiological assessment (n = 18 vessels from 14 patients). We measured FFR (fractional flow reserve), and Doppler-derived coronary flow indices, including CFR (coronary flow reserve) and HMR (hyperaemic microvascular resistance). From the analysed vessels, 18/18 vessels (100%) presented a pathological CFR (<2.5), indicative of coronary microvascular dysfunction (CMD), and 3/18 (17%) demonstrated obstructive epicardial coronary disease (FFR ≤ 0.8). A large proportion of vessels (15/18; 83%) showed discordant FFR/CFR with preserved FFR and low CFR. 47% of the coronary arteries in patients with AF and non-obstructive epicardial coronary disease presented structural CMD (HMR ≥ 2.5 mmHg/cm/s), and were associated with high BMR and an impaired response to adenosine. Conversely, vessels from patients with AF and non-obstructive epicardial coronary disease with functional CMD (HMR < 2.5 mmHg/cm/s) showed higher bAPV. The permanent AF subpopulation presented increased values of HMR and BMR compared to persistent AF, while structural CMD was more often associated with persistent symptoms at 3 months, taking into account the limited sample size of our study. Our findings highlight a systematically impaired CFR in patients with AF even in the absence of obstructive epicardial coronary disease, indicative of CMD. In addition, patients with AF presented more prevalent structural CMD (HMR ≥ 2.5 mmHg/cm/s), characterized by reduced hyperaemic responses to adenosine, possibly interfering with the FFR assessment.

Value of fractional flow reserve derived from coronary computed tomographic angiography and plaque quantitative analysis in predicting adverse outcomes of non-obstructive coronary heart disease

To investigate the value of coronary computed tomographic angiography (CCTA)-based fractional flow reserve (CT-FFR) and plaque quantitative analysis in predicting adverse outcomes in patients with non-obstructive coronary heart disease (CAD). Clinical data of patients with non-obstructive CAD who underwent CCTA at the Affiliated Hospital of Jiangnan University from March 2014 to March 2018 were retrospectively analyzed and followed up, and the occurrence of major adverse cardiovascular event (MACE) was recorded. The patients were divided into MACE and non-MACE groups according to the occurrence of MACE. The clinical data, CCTA plaque characteristics including plaque length, stenosis degree, minimum lumen area, total plaque volume, non-calcified plaque volume, calcified plaque volume, plaque burden (PB) and remodelling index (RI), and CT-FFR were compared between the two groups. Multivaritate Cox proportional risk model was used to evaluate the relationship between clinical factors, CCTA parameters and MACE. The receiver operator characteristic curve (ROC curve) was used to assess the predictive power of outcome prediction model based on different CCTA parameters. Finally 217 patients were included, of which 43 (19.8%) had MACE and 174 (80.2%) did not. The median follow-up interval was 24 (16, 30) months. The CCTA showed that patients in the MACE group had more severe stenosis than that in the non-MACE group [(44.3±3.8)% vs. (39.5±2.5)%], larger total plaque volume and non-calcified plaque volume [total plaque volume (mm3): 275.1 (197.1, 376.9), non-calcified plaque volume (mm3): 161.5 (114.5, 307.8) vs. 117.9 (77.7, 185.5)], PB and RI were larger [PB: 50.2% (42.1%, 54.8%) vs. 45.1% (38.2%, 51.7%), RI: 1.19 (0.93, 1.29) vs. 1.03 (0.90, 1.22)], CT-FFR value was lower [0.85 (0.80, 0.88) vs. 0.92 (0.87, 0.97)], and the differences were statistically significant (all P < 0.05). Cox regression analysis showed that non-calcified plaques volume [hazard ratio (HR) = 1.005. 95% confidence interval (95%CI) was 1.025-4.866], PB ≥ 50% (HR = 3.146, 95%CI was 1.443-6.906), RI ≥ 1.10 (HR = 2.223, 95%CI was 1.002-1.009) and CT-FFR ≤ 0.87 (HR = 2.615, 95%CI was 1.016-6.732) were independent predictors of MACE (all P < 0.05). The model based on CCTA stenosis degree+CT-FFR+quantitative plaque characteristics (including non-calcified plaque volume, RI, PB) [area under the ROC curve (AUC) = 0.91, 95%CI was 0.87-0.95] had significantly better predictive efficacy for adverse outcomes than the model based on CCTA stenosis degree (AUC = 0.63, 95%CI was 0.54-0.71) and the model based on CCTA stenosis degree+CT-FFR (AUC = 0.71, 95%CI was 0.63-0.79; both P < 0.01). CT-FFR and plaque quantitative analysis based on CCTA are helpful in predicting adverse outcomes in patients with non-obstructive CAD. Non-calcified plaque volume, RI, PB and CT-FFR are important predictors of MACE. Compared with the prediction model based on stenosis degree and CT-FFR, the combined plaque quantitative index can significantly improve the prediction efficiency of adverse outcomes in patients with non-obstructive CAD.

Association of Long Noncoding RNA Expression Signatures with Stress-Induced Myocardial Perfusion Defects.

Stress-induced myocardial perfusion defects found in dipyridamole-thallium-201 single-photon emission computed tomography imaging may indicate vascular perfusion abnormalities and risk of obstructive or nonobstructive coronary heart disease. Besides nuclear imaging and subsequent coronary angiography (CAG), no blood test can indicate whether dysregulated homeostasis is associated with stress-induced myocardial perfusion defects. This study investigated the expression signature of long noncoding RNAs (lncRNAs) and genes involved in vascular inflammation and stress response in the blood of patients with stress-induced myocardial perfusion abnormalities (n = 27). The results revealed an expression signature consisting of the upregulation of RMRP (p < 0.01) and downregulations of THRIL (p < 0.01) and HIF1A (p < 0.01) among patients with a positive thallium stress test and no significant coronary artery stenosis within 6 months after baseline treatment. We developed a scoring system based on the expression signatures of RMRP, MIAT, NTT, MALAT1, HSPA1A, and NLRP3 to predict the need for further CAG among patients with moderate-to-significant stress-induced myocardial perfusion defects (area under the receiver operating characteristic curve = 0.963). Therefore, we identified a dysregulated expression profile of lncRNA-based genes in the blood that could be valuable for the early detection of vascular homeostasis imbalance and personalized therapy.

Advances in Single-Photon Emission Computed Tomography

The clinical presentation of coronary artery disease (CAD) has changed during the last 20years with less ischemia on stress testing and more nonobstructive CAD on coronary angiography. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging should include the measurement of myocardial flow reserve and assessment of coronary calcium for the diagnosis of nonobstructive CAD and coronary microvascular disease. SPECT/CT systems provide reliable attenuation correction for better specificity and low-dose CT for coronary calcium evaluation. SPECT MFR measurement is accurate, well validated, and repeatable.

CE-454610-1 VENTRICULAR FIBRILLATION REQUIRING EXTRACORPOREAL RESUSCITATION DURING RADIOFREQUENCY ABLATION IN THE CORONARY SINUS

Coronary vasospasm is a rarely reported but potentially catastrophic complication of radiofrequency ablation (RFA). The mechanism is not fully understood but may be related to thermal energy transfer, inflammatory markers released during ablation, and/or alterations in autonomic tone from stimulation of epicardial ganglionated plexi. While most vasospasm occurrences appear subclinical and self-limited, there are exceptions. To highlight an exceptional, life-threatening case of RFA-induced coronary vasospasm. N/A A 62-year-old man with persistent AF and five prior ablations (including one at our institution) presented for ablation of atypical atrial flutter. Termination of the flutter occurred with RFA (7 lesions) at the left atrial roof. There was also a breakthrough of conduction through a prior posterior mitral isthmus line, so coronary sinus (CS) lesions were placed to re-attain mitral block. Two irrigated RF lesions (#1 - 59 seconds, max 26 Watts; #2 - 40 seconds, max 33 Watts) were placed, but 7 seconds into the 3rd lesion (max 27 Watts), ventricular fibrillation (VF) occurred, initially refractory to multiple external shocks. ACLS/CPR commenced. Arterial access was rapidly achieved, and initial coronary angiography simply revealed diffusely slow/no flow related to ongoing VF. Emergent veno-arterial extracorporeal membrane oxygenation (VA ECMO) cannulation was initiated, following which the VF was successfully defibrillated, converting to sinus rhythm. Repeat coronary angiography revealed (known) minimal non-obstructive coronary disease as well as a focal, severe spasm of a dominant left circumflex artery adjacent to the location of CS ablation. Intracoronary nitroglycerin resulted in minimal initial angiographic improvement, so balloon angioplasty and deployment of a drug eluting stent was performed (post: TIMI III flow). The patient made a full recovery and was discharged home on post-procedure day 6 without long-term sequelae. This case underscores a life-threatening complication of RFA within the CS leading to coronary vasospasm and refractory VF. Expedient intervention with extracorporeal resuscitation and support can stabilize patients to allow time to manage arrhythmias and resolve spasm either pharmacologically or procedurally.

Role of Intracoronary Imaging in Myocardial Infarction with Non-Obstructive Coronary Disease (MINOCA): A Review

Myocardial infarction with non-obstructive coronary artery disease occurs in 6% to 15% of all presentation of myocardial infarctions. The pathophysiologic mechanisms of MINOCA include epicardial vasospasm, coronary microvascular disorder, spontaneous coronary artery dissection, and coronary thrombus/embolism. The diagnosis is challenging, supported by intracoronary imaging with intravascular ultrasound (IVUS) and optical coherent tomography (OCT), coronary physiology testing, and cardiac magnetic resonance imaging (CMR). OCT is able to identify atherosclerotic causes of MINOCA (plaque erosion, plaque rupture, and calcified nodule) and nonatherosclerotic causes (spontaneous artery dissection, and spasm). In this review, we summarize the performance of the two intracoronary imaging modalities (IVUS and OCT) in MINOCA and discuss the importance of supplementing these modalities with CMR in order to drive target therapy.

Ischemia with non-obstructive coronary disease as detected by myocardial scintigraphy: A benign or malignant prognosis?

Ischemia with non-obstructive coronary disease as detected by myocardial scintigraphy: A benign or malignant prognosis?

Positive Stress Electrocardiography in Patients With Non-obstructive Coronary Disease.

Introduction The episodes of myocardial ischemia in patients with non-obstructive coronary disease are extremely variable in provoking factors and presentation. Purpose We investigated the significance of coronary blood flow velocity and epicardial diameter as correlates of a positive electrocardiographic exercise stress test (ExECG) in hospitalized patients with unstable angina and non-obstructive coronary artery disease. Methods The study was a single-center cohort retrospective. ExECG was performed and analyzed in a group of 79 patients with non-obstructive coronary disease (coronary stenoses < 50%). Thirty-one percent of the patients (n=25) were diagnosed with slow coronary flow phenomenon, SCFP; 40.5% (n=32) - patients with hypertensive disease, left ventricular hypertrophy (LVH), and slow epicardialflow; 27.8% (n=22) with hypertension, left ventricular hypertrophy and normal coronaryflow. The patients were hospitalized in University Hospital "Alexandrovska," Sofia in the period 2006-2008. Results The frequency of positive ExECG is increased as a trend was associated with smaller epicardial diameters and pronounced delay in epicardial coronaryflow.In the subgroup with SCFP, the risk for a positive ExECG test was determined by slower coronary flow (36.5±7.7 frames vs. 30.3±4.4 frames, p=0.044) and borderline significant by epicardial lumen diameters (3.3±0.8 mm vs. 4.1±1.0 mm, p=0.051) and greater myocardial mass (92.8±12.6 g/m2 vs. 82.9±8.6 g/m2, p=0.054). In cases of left ventricular hypertrophy, which included both patients with the normal and slow epicardialflow, there were no statistically significant correlates of an abnormal exercise stress ECG test. Conclusions In patients with non-obstructive coronary atherosclerosis and predominantly slow epicardial coronary flow, the provoking of ischemia at an electrocardiographic exercise stress test is associated with the lower epicardial flow velocity at rest and with the smaller epicardial diameter. In SCFP, the risk for an abnormal stress test is determined by slower coronary flow, smaller epicardial lumen diameter, and greater myocardial mass.The presence and size of the plaque burden are not associated with a greater risk of a positive ExECG in these patients.

Nicorandil, Novel Potassium Adenosine Triphosphate Channel (K+ ATP) Opener in IschemiaWithNon-Obstructive Coronary Arteries (INOCA) and Atherosclerotic Cardiovascular Disease (ASCVD): Delphi Consensus Statement.

Coronary artery disease (CAD) is a significant health concern today that has assumed epidemic proportions worldwide and in India. The pathobiology of CAD or ischemiawithnon-obstructive coronary arteriesdisease (INOCA) in most cases involves coronary microvascular dysfunction (CMD) that often requires personalized pheno-approach based on the risk stratification and diagnostic yield, especially in patients with recurrent angina episodes. Chronic therapy with anti-anginal is often fraught with challenges of unipolar action, tolerance, and oxidative stress that precludes consistent benefits in clinical cases of CMD represented bymicrovascular angina (MVA). To further elucidate the clinical role and relevance of long-term vasodilator therapy, including nicorandil, a Knowledge, Attitude, and Perception (KAP) survey was planned to be conducted. Based on responses to the KAP survey questionnaire, Delphi-mediated graded recommendations were developed by a specialist panel as per Agency of Health Care and Quality Systems (AHRQ) criteria. Management of INOCA with MVA requires a multidisciplinary approach involving non- or invasive procedures that may be relevant for persistent or refractory angina before instituting symptomatic and long-term use of nicorandil for beta-blocker intolerant and associated clinical phenotypes. The analyses provide a real-life approach to the management of INOCA and angina non-obstructive coronary artery disease (ANOCA) with underlying CMD that may be relevant in outpatient settings in India.