Pathophysiology and management of patients with chest pain and normal coronary arteriograms (cardiac syndrome X)

Drug repurposing-a promising approach for patients with angina but non-obstructive coronary artery disease (ANOCA)

In today's era of individualized precision medicine drug repurposing represents a promising approach to offer patients fast access to novel treatments. Apart from drug repurposing in cancer treatments, cardiovascular pharmacology is another attractive field for this approach. Patients with angina pectoris without obstructive coronary artery disease (ANOCA) report refractory angina despite standard medications in up to 40% of cases. Drug repurposing also appears to be an auspicious option for this indication. From a pathophysiological point of view ANOCA patients frequently suffer from vasomotor disorders such as coronary spasm and/or impaired microvascular vasodilatation. Consequently, we carefully screened the literature and identified two potential therapeutic targets: the blockade of the endothelin-1 (ET-1) receptor and the stimulation of soluble guanylate cyclase (sGC). Genetically increased endothelin expression results in elevated levels of ET-1, justifying ET-1 receptor blockers as drug candidates to treat coronary spasm. sGC stimulators may be beneficial as they stimulate the NO-sGC-cGMP pathway leading to GMP-mediated vasodilatation.

Aerobic high-intensity interval exercise training in patients with angina and no obstructive coronary artery disease: feasibility and physiological effects

Aims

Patients with chest pain and normal coronary angiogram [angina with normal coronary arteries (ANOCA)] constitute a therapeutic problem with considerable functional limitation and reduced quality of life. The aims of the current pilot study were to (i) explore if a structured aerobic high-intensity interval training (HIT) program for 12 weeks was feasible in patients with ANOCA, and (ii) to assess mechanisms related to symptoms in this population.

Methods and results

Sixteen patients with ANOCA underwent a 3-month aerobic HIT program with one-to-one monitored exercise sessions on treadmill in a 4 min × 4 manner, three times a week. Four patients served as controls. Coronary flow velocity reserve (CFVR) transthoracic Doppler, flow-mediated vasodilation (FMD) and VO_2max was measured at baseline and after 12 weeks. The average attendance to training sessions was 82.3% ± 10.1 (56-94). CFVR in the training group increased from 2.50 ± 0.48 to 3.04 ± 0.71 (P < 0.001) whereas FMD increased from 4.19 ± 2.42% to 8.28 ± 2.85% (P < 0.001). Improvement in CFVR correlated with the relative improvement in FMD (R = 0.45, P = 0.047). This was associated with an increase in VO_2max from 28.75 ± 6.51 mL/kg/min to 31.93 ± 6.46 mL/kg/min (P < 0.001).

Conclusion

A 3-month program of monitored HIT was feasible, with high adherence resulting in improved functional capacity in patients with ANOCA. CFVR improved and this improvement was associated with improved FMD.

ClinicalTrialsgov Identifier

NCT02905630.

Updates on Pharmacologic Management of Microvascular Angina

Microvascular angina (MVA), historically called cardiac syndrome X, refers to angina with nonobstructive coronary artery disease. This female-predominant cardiovascular disorder adds considerable health-related costs due to repeated diagnostic angiography and frequent hospital admissions. Despite the high prevalence of this diagnosis in patients undergoing coronary angiography, it is still a therapeutic challenge for cardiologists. Unlike obstructive coronary artery disease, with multiple evidence-based therapies and management guidelines, little is known regarding the management of MVA. During the last decade, many therapeutic interventions have been suggested for the treatment of MVA. However, there is a lack of summarization tab and update of current knowledge about pharmacologic management of MVA, mostly due to unclear pathophysiology. In this article, we have reviewed the underlying mechanisms of MVA and the outcomes of various medications in patients with this disease. Contrary to vasospastic angina in which normal angiogram is observed as well, nitrates are not effective in the treatment of MVA. Beta-blockers and calcium channel blockers have the strongest evidence of improving the symptoms. Moreover, the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, statins, estrogen, and novel antianginal drugs has had promising outcomes. Investigations are still ongoing for vitamin D, omega-3, incretins, and n-acetyl cysteine, which have resulted in beneficial initial outcomes. We believe that the employment of the available results and results of the future large-scale trials into cardiac care guidelines would help reduce the global cost of cardiac care tremendously.

Association of uric acid levels with cardiac syndrome X: A meta-analysis

Objective: The pathogenesis of elevated uric acid (UA) levels in patients with cardiac syndrome X (CSX) is unclear, and the results presented in recent papers on UA levels in patients with CSX are controversial. Therefore, we conducted a meta- analysis to assess the relationship between UA levels and CSX.

Methods: Three databases, including the Web of Science, EMBASE and PubMed, were systematically searched until January 2022. Fixed-effect and random-effects models were used to analyze the relationship between UA levels and CSX. Subgroup analysis and sensitivity analysis were also performed.

Results: Six studies involving 406 CSX patients and 267 non-CSX were included. Our results showed a significant relationship between UA levels and CSX, with a pooled SMD of 0.68 (95% CI 0.37 to 1.00; p < 0.0001). We also found a close relationship between UA levels and CSX for patients ≥ 55 years old (SMD:0.70, 95% CI: 0.41 to 0.99, p < 0.00001), for patients < 55 years old (SMD: 0.68, 95% CI: 0.25 to 1.12, p =0 .002), for women ≥ 60% (SMD: 0.77, 95% CI: 0.33 to 1.14, p =0 .0004), for women < 60% (SMD: 0.61, 95% CI:0.23 to 0.98, p =0 .001), for BMI ≥ 28 Kg/m² (SMD :0.61, 95% CI: 0.23 to 0.98, p =0 .001), for BMI < 28 Kg/m² (SMD:0.75, 95% CI: 0.31 to 1.19, p =0 .0009), for publication years ≥ 2012 (SMD :0.69, 95% CI: 0.23 to 1.15, p = 0.003), for publication years < 2012 (SMD:0.73, 95% CI:0.41 to 1.05, p < 0.00001), and for Turkey (SMD:0.75, 95% CI:0.38 to 1.11, p <.0001). Sensitivity analysis showed that the pooled results remained consistent after removing any one study or converting the random-effects model to fixed-effects model.

Conclusion: Our results indicated a strong association between high UA levels and CSX. However, more well-designed studies are needed to investigate whether early treatment of hyperuricemia can reduce the incidence of CSX.

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.

Systemic Immune-Inflammation Index as a Predictor of Microvascular Dysfunction in Patients With Cardiac Syndrome X

The systemic immune inflammation index (SII; platelet count x neutrophil-lymphocyte ratio), a new marker, predicts adverse clinical outcomes in many conditions, including acute and chronic coronary syndromes, pulmonary embolism, cancers, and contrast nephropathy. The aim of this study was to determine the relationship between SII and microvascular dysfunction in patients with Cardiac Syndrome X (CSX); 105 patients with CSX and 105 patients with normal coronary arteries were included. Microvascular dysfunction was determined angiographically using myocardial blush grade (MBG) and total myocardial blush score (TMBS). We observed that the SII levels were higher in the CSX (+) group (687 [355-2211] vs 418 [198-1614], P<.001). The SII levels were also found to be significant independent predictors for CSX in multiple regression analysis (P=.001). SII levels >440 had 83.8% sensitivity and 55.2% specificity (area under the curve [AUC]: .923, 95% CI: .895-.999, P<.001) for predicting CSX. There is a significant correlation between SII levels and CSX.

Risk Factors Predisposing to Angina in Patients with Non-Obstructive Coronary Arteries: A Retrospective Analysis

No hemodynamically significant atherosclerotic plaques are observed in up to 30% of patients reporting angina and undergoing coronary angiography. To investigate risk factors associated with non-obstructive coronary artery disease (NOCAD), we analyzed the medical records of, consecutively, 136 NOCAD subjects and 128 patients with significant stenosis in at least one coronary artery (the OCAD group). The blood concentrations of the TC (4.40 [3.78−5.63] mmol/L vs. 4.12 [3.42−5.01] mmol/L; p = 0.026), LDL-C (2.32 [1.80−3.50] mmol/L vs. 2.10 [1.50−2.70] mmol/L; p = 0.003), non-HDL-C (2.89 [2.29−4.19] mmol/L vs. 2.66 [2.06−3.39] mmol/L; p = 0.045), as well as the LDL-C/HDL-C ratio (1.75 [1.22−2.60] vs. 1.50 [1.10−1.95]; p = 0.018) were significantly increased in the NOCAD patients compared to the OCAD group due to the lower prevalence and intensity of the statin therapy in the NOCAD individuals (p < 0.001). Moreover, the abovementioned lipid parameters appeared to be valuable predictors of NOCAD, with the LDL-C (OR = 1.44; 95%CI = 1.14−1.82) and LDL-C/HDL-C (OR = 1.51; 95%CI = 1.13−2.02) showing the highest odds ratios. Furthermore, multivariable logistic regression models determined female sex as the independent risk factor for NOCAD (OR = 2.37; 95%CI = 1.33−4.20). Simultaneously, arterial hypertension substantially lowered the probability of NOCAD (OR = 0.21; 95%CI = 0.10−0.43). To conclude, female sex, the absence of arterial hypertension, as well as increased TC, LDL-C, non-HDL, and LDL-C/HDL-C ratio are risk factors for NOCAD in patients reporting angina, potentially as a result of poor hypercholesterolemia management.

A Pilot study on correlation between Zinc and Magnesium serum concentrations and coronary slow flow phenomenon

BACKGROUND

The pathophysiology of slow flow includes microvascular disorders, endothelial dysfunction, subclinical atherosclerosis, inflammation and anatomical factors. The role of magnesium and zinc in the development of microvascular and endothelial dysfunctions as well as atherosclerosis has been proven in previous studies, and the mechanism of the development has been studied. The aim of current study was to evaluate the serum concentration of zinc and magnesium in patients with epicardial coronary artery slow flow.

DESIGN

125 patients who referred to Ghaem Hospital in Mashhad were selected based on inclusion and exclusion criteria. Magnesium and Zinc levels were evaluated in patients. The plasma levels of studied elements were compared among the different groups and the rate of coronary artery slow flow was evaluated based on the TIMI score.

RESULTS

The results of present study indicated that the serum level of Magnesium in the studied groups did not show a significant correlation with rate of coronary artery slow flow (P> 0.05). Serum Zinc concentration was significantly different in the studied groups, which means serum Zinc level in patients without coronary artery occlusion and  without epicardial slow flow were significantly higher than other groups (P> 0.01).

CONCLUSION

In the present study, no significant relationship was found between the serum level of zinc and magnesium with the intensity of coronary artery slow flow based on TIMI, and further studies seem to be needed to investigate this relationship.

Helicobacter pylori infection and susceptibility to cardiac syndrome X: A systematic review and meta-analysis

BACKGROUND

Cardiac syndrome X (CSX) is characterized by persistent angina with normal coronary arteries. Several pathophysiologic mechanisms have been introduced, particularly Helicobacter pylori (H. pylori) infection.

AIM

To investigate the association between H. pylori infection and CSX.

METHODS

All studies related to H. pylori infection and CSX were evaluated by comprehensive searches of global databases such as ISI Web of Knowledge, PubMed, Scopus, EMBASE, and Google scholar. Statistical analyses of selected articles were evaluated based on the summary odds ratio (OR). Finally, heterogeneity and publication bias were estimated using the I² statistic and Cochrane Q-test as well as Begg’s and Egger’s tests.

RESULTS

A total of 11 studies met our inclusion criteria and 1435 patients (63% female, and 37% male) were reviewed. A significant association was observed between female patients and this syndrome (P = 0.02). Our results showed a positive association between infection with this pathogen and presence of CSX (OR: 5.65; 95% confidence interval [CI]: 4.17-7.64; I²: 82.20). However, no significant association was observed with cagA-positive H. pylori strains and this syndrome (OR: 0.97; 0.56-1.70 with 95%CI). Given the heterogeneity and publication bias, the results need to confirmed by further prospective investigation.

CONCLUSION

Based on our results, H. pylori infection is associated with an increased risk of CSX. This bacterium appears to play a major role in the pathogenesis of CXS by inducing persistent inflammation.

Epicardial adipose tissue differentiates in patients with and without coronary microvascular dysfunction

BACKGROUND/OBJECTIVES

Coronary microvascular dysfunction (CMD) is a common disorder, leading to symptoms similar to obstructive coronary artery disease and bears important prognostic implications. Local inflammation is suggested to promote development of CMD. Epicardial adipose tissue (EAT) is a local visceral fat depot surrounding the heart and the coronary arteries, modifying the inflammatory environment of the heart. We compared EAT in patients with and without CMD.

METHODS

We retrospectively included consecutive patients undergoing diagnostic coronary angiography as well as transthoracic echocardiography between March and October 2016. EAT thickness was defined as space between the epicardial wall of the myocardium and the visceral layer of the pericardium and EAT index was calculated as EAT thickness/body surface area. Logistic regression analysis was used to determine the association of EAT index with the presence of CMD.

RESULTS

Overall, 399 patients (mean age 60.2 ± 14.0 years, 46% male) were included. EAT thickness was significantly higher in patients with CMD compared to patients without CMD (EAT thickness 4.4 ± 1.8 vs. 4.9 ± 2.4 mm, p = 0,048 for patients without and with CMD, respectively). In univariate regression analysis, EAT index was associated with a 30% higher frequency of CMD (odds ratio [95% confidence interval]: 1.30 [1.001-1.69], p = 0.049). Effect sizes remained stable upon adjustment for body mass index (BMI, 1.30 [1.003-1.70], p = 0.048), but were attenuated when ancillary adjusting for age and gender (1.17 [0.90-1.54, p = 0.25). The effect was more pronounced in patients >65 years of age and independent of BMI and sex (1.85 [1.14-3.00], p = 0.013).

CONCLUSION

EAT thickness is independently associated with CMD and can differentiate between patients with and without CMD especially in older age groups. Our results support the hypothesis that modulation of local inflammation by epicardial fat is involved in the development of CMD.

Complete versus incomplete coronary revascularization: definitions, assessment and outcomes

Coronary artery disease is the leading cause of morbidity and mortality worldwide. Selected patients with obstructive coronary artery disease benefit from revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. Many (but not all) studies have demonstrated increased survival and greater freedom from adverse cardiovascular events after complete revascularization (CR) than after incomplete revascularization (ICR) in patients with multivessel disease. However, achieving CR after PCI or CABG surgery might not be feasible owing to patient comorbidities, anatomical factors, and technical or procedural considerations. These factors also mean that comparisons between CR and ICR are subject to multiple confounders and are difficult to understand or apply to real-world clinical practice. In this Review, we summarize and critically appraise the evidence linking various types of ICR to adverse outcomes in patients with multivessel disease and stable ischaemic heart disease, non-ST-segment elevation acute coronary syndrome or ST-segment elevation myocardial infarction, with or without cardiogenic shock. In addition, we provide practical recommendations for revascularization in patients with high-risk multivessel disease to optimize their long-term clinical outcomes and identify areas requiring future clinical investigation.

Effects of Statin Treatment on Patients with Angina and Normal or Nearly Normal Angiograms

This article offers an updated and comprehensive overview of major findings on the effects of statin treatment in patients with chronic angina but without any epicardial coronary artery with obstructive lesion.

Facial pain associated with cardiac origin

BACKGROUND

Ischemic heart disease manifests as pain on the left side, in the retrosternal or the precordial region, with subsequent radiation to the ipsilateral shoulder, face, and cervical region. Less frequently, it may manifest solely as face pain.

CASE DESCRIPTION

A 57-year-old man sought care at the Massachusetts General Hospital Oral and Maxillofacial Pain Center with a symptom of pain in the mandibular left posterior region, in the medial aspect of the ipsilateral eye, and in the left side of the neck. The pain had started approximately 8 months previously as a mild, constant dull ache in the mandibular left posterior region. However, it became severe in intensity and sharp in quality and radiated toward the medical aspect of the ipsilateral eye and lateral neck region after intense physical activity. Results from comprehensive diagnostic evaluation and a series of diagnostic tests suggested that the facial pain was associated with cardiovascular disease. There was complete resolution of pain symptoms after the patient received appropriate pharmacotherapy.

PRACTICAL IMPLICATIONS

Association of pain with exercise and termination of pain with rest and the presence of risk factors for cardiovascular disease necessitate a thorough investigation of rare and fatal causes of facial pain.

Reappraisal of Ischemic Heart Disease

In recent years, it has become apparent that coronary microvascular dysfunction plays a pivotal pathogenic role in angina pectoris. Functional and structural mechanisms can affect the physiological function of the coronary microvasculature and lead to myocardial ischemia in people without coronary atheromatous disease and also in individuals with obstructive coronary artery disease. Abnormal dilatory responses of the coronary microvessels, coronary microvascular spasm, and extravascular compressive forces have been identified as pathogenic mechanisms in both chronic and acute forms of ischemic heart disease. The condition characterized by anginal symptoms and evidence of myocardial ischemia triggered by coronary microvascular dysfunction, in the absence of obstructive coronary disease, is known as microvascular angina. The concept of microvascular angina, however, may extend further to include patients with obstructive coronary artery disease and individuals with angina after coronary revascularization or heart transplantation because coronary microvascular dysfunction contributes to myocardial ischemia in many such patients. Patients with microvascular angina constitute a sizeable proportion of all cases of stable angina undergoing diagnostic coronary angiography and of those with persisting angina after successful coronary revascularization. Coronary microvascular dysfunction is also often responsible for angina in individuals with cardiomyopathy and heart valve disease as well as acute coronary syndrome cases such as Takotsubo syndrome and myocardial infarction with no obstructive coronary artery disease. Patients with stable microvascular angina present typically with effort or rest chest pain and a reduced coronary flow reserve or microvascular spasm. This condition, which affects women and men, can markedly impair quality of life and prognosis and represents a substantial cost burden to healthcare systems and individuals alike. In recent years, progress in the diagnosis of myocardial ischemia and the use of tests to investigate functional and structural causes for a reduced coronary flow reserve and microvascular spasm have allowed the identification of an increased number of cases of microvascular angina in everyday clinical practice. Although some of the available anti-anginal drugs may be helpful, treatment of coronary microvascular dysfunction remains a major challenge. The present article discusses the fundamental role that coronary microvascular dysfunction plays in the pathogenesis of ischemic heart disease, the clinical characteristics of patients presenting with microvascular angina, and possible diagnostic and therapeutic strategies.

Assessment of the relationship between coronary flow rates and myocardial perfusion abnormality in patients with nonobstructive coronary artery disease: an observational study in cardiac syndrome X and coronary slow flow

OBJECTIVES

In this study, we evaluated and compared the level of myocardial ischaemia caused by cardiac syndrome X (CSX) and coronary slow flow (CSF) with single photon emission computed tomography myocardial perfusion imaging (SPECT-MPI), and determined if changes in the level of myocardial ischaemia exist in CSF and CSX cases according to thrombolysis in myocardial infarction frame count (TFC).

MATERIALS AND METHODS

The study population consisted of 66 patients with CSF and 78 angiographically normal patients (36 of them with CSX and 42 of them healthy controls). The coronary flow rates of all patients were documented using TFC. Subsequently, all patients were evaluated with SPECT-MPI and categorized into the following groups according to their results: patients with CSF, patients with CSX, and patients with normal coronary arteries. Finally, we investigated whether a relationship existed between the SPECT-MPI and TFC results from these three groups.

RESULTS

All ischaemia scores for MPI were significantly higher in the CSF group than in the CSX and control groups (P < 0.05). TFC was significantly associated with the severity of ischaemia in the CSF patients. There was a significant positive correlation between the summon difference score (SDS) and mean TFC value (P < 0.05) as well as between the SDS and each individual coronary TFC value in the CSF patients (P < 0.05). The number of vessels involved in CSF was positively correlated with the SDS.

CONCLUSION

CSF is associated with more severe myocardial ischaemia than CSX. The level of myocardial ischaemia on SPECT-MPI was correlated with the TFC and the number of affected coronary vessels in patients with CSF. These results suggest that CSF is a more serious clinical entity than CSX, and that the clinical severity of CSF appears to increase as the coronary flow rate decreases.

High-Resolution Body Surface Potential Mapping in Exercise Assessment of Ischemic Heart Disease

Standard 12-lead ECG exercise testing is commonly used for screening of ischemic heart disease (IHD). We studied if high-resolution body surface potential mapping (HR-BSPM) during exercise offers advantages over current standards in noninvasive evaluation of IHD. This study was carried out on 90 IHD patients and 33 healthy controls. The 67-lead HR-BSPM was recorded at rest and during exercise. Twenty-one ECG parameters including classical ST criteria were compared. The effectiveness of methods was verified based on the results of SPECT and coronary angiography. The most effective parameters in the diagnosis of IHD were: amplitude parameter ΔST60 and δT parameter showing T-wave morphology changes during exercise. The sensitivities/specificities of ΔST60 and δT parameters for the HR-BSPM were 70/69 and 59/62%, while for the standard 12-lead ECG system they were: 63/62 and 59/56%. These results demonstrate the usefulness of HR-BSPM measurements during exercise. HR-BSPM resulted in higher sensitivities and specificities compared to the standard 12-lead exercise test. The advantage was partially associated with observed ischemic changes outside standard precordial leads position that were not visible when using the standard 12-lead exercise test. This justifies research into the optimization of the number and position of ECG leads in exercise testing.

Evaluation of serum sST2 and sCD40L values in patients with microvascular angina

OBJECTIVES

Coronary microvascular dysfunction plays a major role in the pathogenesis of microvascular angina (MVA). Along with endothelial dysfunction, microvascular atherosclerosis and inflammation seem to contribute to the development of coronary microvascular dysfunction. Serum soluble ST2 (sST2) and serum soluble CD40 ligand (sCD40L) are two biomarkers associated with inflammation and atherosclerosis. The aim of this study was to investigate the role of these biomarkers in the pathogenesis of MVA and determine their possible association with coronary microvascular dysfunction.

METHODS

A total of 152 patients were included in the study. Ninety-one patients with MVA {median age 56 years (40-79), of which 55 are women} and sixty-one controls {median age 52 (38-76), of which 29 are women} were included in the study. Serum concentration of sST2 and sCD40L were measured with a commercially available ELISA kit.

RESULTS

Serum sST2 (median 13.6 ng/ml; interquartile range (IQR), 3.5-63.8 ng/ml vs median 10.6 ng/ml; IQR, 2.9-34.2 ng/ml, p < 0.0005) and sCD40L (median 5.3 ng/ml; IQR, 0.5-20.6 ng/ml vs median 2.2 ng/ml; IQR, 0.7-10.8 ng/ml, p < 0.0005) were significantly higher in patients with MVA compared to controls. Analysis of the associations between these biomarkers and potential contributors of MVA revealed that serum sST2 showed a positive correlation with LDL-cholesterol (r = 0.19, p = 0.016) and serum sCD40L concentrations correlated positively with hs-CRP (r = 0.22, p = 0.005). In logistic regression analysis, sCD40L and hs-CRP but not sST2 were found to be significantly associated with MVA.

CONCLUSION

Higher serum concentrations of sST2 and sCD40L in MVA patients may be associated with inflammatory activation and coronary microvascular dysfunction. Larger studies are required for understanding their role in the pathogenesis of inflammatory and possibly fibrotic process in MVA patients.

Observational Study of the Association between TCM Zheng and Types of Coronary Artery Stenosis: Protocol of a Multicenter Case Series Study

Background

Coronary artery stenosis is the major pathological change of coronary heart disease (CHD). Within the framework of traditional Chinese medicine (TCM) theory, some kinds of TCM Zheng could exist in patients with CHD; accordingly, TCM practitioners could provide appropriate TCM therapy. However, little is known about the association between TCM Zheng and types of coronary artery stenosis. Such knowledge could help improve the accuracy and effectiveness of efforts to combine CHD treatment with TCM therapy. Therefore, the aim of this study is to determine the association between TCM Zheng and types of coronary artery stenosis.

Methods and Design

This is a multicenter, large sample, case series study in 4 tertiary A hospitals from 3 provinces in China. A total of 3,000 eligible patients diagnosed with atherosclerosis or CHD and selected to undergo coronary angiography (CAG) will be enrolled in this study. We will use electronic case report forms (eCRF) to collect information, including baseline characteristics, TCM symptoms, CAG results, and GRACE scores according to standard operating procedures (SOP). Data will be analyzed by SPSS 20.0.

Ethics

This study is approved by the Ethics Committee of Guang'anmen Hospital of the China Academy of Chinese Medical Sciences (no. 2017-058-KY-01) and is registered with chictr.org (registration number ChiCTR-ROC-17013221).

Evaluation of the coronary flow by the coronary clearance time in patients with cardiac syndrome X

Objective

The vessels involved in the microcirculation are too small to be visualized by conventional angiography and no tools are currently available that can directly evaluate the coronary microcirculation. This study evaluated the coronary clearance frame count (CCFC) in patients with cardiac syndrome X (CSX).

Methods

The retrospective study enrolled patients with angina, who had a positive nuclear imaging test and normal coronary angiography; and a control group consisting of patients who underwent an angiogram to exclude coronary artery disease. Thrombosis in myocardial infarction frame count (TFC) and CCFC for each coronary artery (left anterior descending coronary artery [LAD], circumflex coronary artery [CFX] and right coronary artery [RCA]) were calculated offline.

Results

A total of 71 patients with CSX and 61 control patients were enrolled in the study. No significant differences were found between the two groups regarding the baseline demographic and clinical variables. The TFC of LAD, CFX and RCA were similar between the two groups. The mean CCFC-LAD, CCFC-CFX and CCFC-RCA were significantly longer in the CSX group compared with the control group.

Conclusion

CCFC is a simple, quantitative and highly reproducible method that might be used as a marker of coronary microvascular dysfunction.

Typical angina is associated with greater coronary endothelial dysfunction but not abnormal vasodilatory reserve

BACKGROUND

Typical angina (TA) is defined as substernal chest pain precipitated by physical exertion or emotional stress and relieved with rest or nitroglycerin. Women and elderly patients are usually have atypical symptoms both at rest and during stress, often in the setting of nonobstructive coronary artery disease (CAD).

HYPOTHESIS

To further understand this, we performed subgroup analysis comparing subjects who presented with TA vs nontypical angina (NTA) using baseline data of patients with nonobstructive CAD and coronary microvascular dysfunction (CMD) enrolled in a clinical trial.

METHODS

155 subjects from the RWISE study were divided into 2 groups based on angina characteristics: TA (defined as above) and NTA (angina that does not meet criteria for TA). Coronary reactivity testing (responses to adenosine, acetylcholine, and nitroglycerin), cardiac magnetic resonance-determined myocardial perfusion reserve index (MPRI), baseline Seattle Angina Questionnaire (SAQ), and Duke Activity Status Index (DASI) scores were evaluated.

RESULTS

The mean age was 55 ± 10 years; Overall, 30% of subjects had TA. Baseline shortness of breath, invasively assessed acetylcholine-mediated coronary endothelial function, and SAQ score were worse in the TA group (all P < 0.05), whereas adenosine-mediated coronary flow reserve, MPRI, and DASI score were similar to the NTA group.

CONCLUSIONS

Among subjects with CMD and no obstructive CAD, those with TA had more angina pectoris, shortness of breath, and worse quality of life, as well as more severe coronary endothelial dysfunction. Typical angina in the setting of CMD is associated with worse symptom burden and coronary endothelial dysfunction. These results indicate that TA CMD subjects represent a relatively new CAD phenotype for future study and treatment trials.

Age- and sex-based resource utilisation and costs in patients with acute chest pain undergoing cardiac CT angiography: pooled evidence from ROMICAT II and ACRIN-PA trials

OBJECTIVES

To determine resource utilisation according to age and gender-specific subgroups in two large randomized diagnostic trials.

METHODS

We pooled patient-specific data from ACRIN-PA 4005 and ROMICAT II that enrolled subjects with acute chest pain at 14 US sites. Subjects were randomized between a standard work-up and a pathway utilizing cardiac computed tomography angiography (CCTA) and followed for the occurrence of acute coronary syndrome (ACS) and resource utilisation during index hospitalisation and 1-month follow-up. Study endpoints included diagnostic accuracy of CCTA for the detection of ACS as well as resource utilisation.

RESULTS

Among 1240 patients who underwent CCTA, negative predictive value of CCTA to rule out ACS remained very high (≥99.4%). The proportion of patients undergoing additional diagnostic testing and cost increased with age for both sexes (p < 0.001), and was higher in men as compared to women older than 60 years (43.1% vs. 23.4% and $4559 ± 3382 vs. $3179 ± 2562, p < 0.01; respectively). Cost to rule out ACS was higher in men (p < 0.001) and significantly higher for patients older than 60 years ($2860-5935 in men, p < 0.001).

CONCLUSIONS

CCTA strategy in patients with acute chest pain results in varying resource utilisation according to age and gender-specific subgroups, mandating improved selection for advanced imaging.

KEY POINTS

• In this analysis, CAD and ACS increased with age and male gender. • CCTA in patients with acute chest pain results in varying resource utilisation. • Significant increase of diagnostic testing and cost with age for both sexes. • Cost to rule out ACS is higher in men and patients >60 years. • Improved selection of subjects for cardiac CTA result in more resource-driven implementation.

Clinical characteristics of patients with suspected cardiac chest pain and angiographically normal coronary arteries in a secondary care hospital

BACKGROUND

An important number of patients with suspected cardiac chest pain have non-obstructive coronary artery disease. Our purpose was to describe the clinical characteristics of patients with normal or near-normal coronary arteries in routine cardiological practice in a secondary care hospital.

METHODS

In 2013, consecutive patients referred for invasive coronary angiography with suspected cardiac chest pain were analysed at a single-centre (Westfriesgasthuis, Hoorn, the Netherlands). Coronary arteries were defined as normal or near-normal if they showed no stenosis or only slight wall irregularities on visual assessment. Patients with a final non-cardiac diagnosis for the chest pain were excluded.

RESULTS

A total of 558 patients were included. Of these, 151 (27%) showed normal or near-normal coronary arteries on visual assessment. This group of patients were significantly more often female (p < 0.001), younger (p < 0.001) and non-diabetic (p = 0.002). Forty percent of hospitalised patients who had normal or near-normal coronary arteries at coronary angiography showed an elevated troponin.

CONCLUSION

In routine cardiological practice, around 1 out of 4 patients with suspected cardiac chest pain undergoing invasive angiography had normal or near-normal coronary arteries. We suggest that premenopausal women with suspected cardiac chest pain could be considered for non-invasive coronary imaging as a first step in clinical practice.

The influence of sex on microvascular function

A number of studies consistently report higher rates of all clinical outcomes including postinfarction mortality, need for repeat revascularization, and reinfarction in women with cardiovascular diseases than in men. As well, the gender gap in the prevalence of cardiovascular diseases decreases progressively with increasing age. Yet, the diagnosis and treatment of these diseases differ between genders and women remain underdiagnosed for coronary heart disease. In a recent retrospective analysis we showed that, along with vessel under study and age, gender is a determinant of adenosine responses during studies of fractional flow reserve, an effect that was probably due to differences in microvascular function and that influenced the interpretation of fractional flow reserve data. These data demonstrate that not only the clinical presentation is different, but also the diagnostic approach to coronary artery disease might differ between sexes.A gap still exists in the understanding of the mechanisms, awareness, and treatment of coronary artery disease in women, but also, as we show, in the application of diagnostic modalities that are well established in men.

Myocardial scintigraphy - a method for detecting cardiac comorbidity in psoriasis patients?

BACKGROUND

In recent years, cardiac comorbidities in psoriasis patients have increasingly moved into the focus of clinical research. The objective of the present study was to evaluate myocardial scintigraphy as a screening method in patients with psoriasis.

PATIENTS AND METHODS

Assessment of various comorbidities in 50 psoriasis patients without clinical symptoms of cardiac disease. Myocardial scintigraphy was employed to detect cardiac risk/exercise-induced ischemia.

RESULTS

Twenty-eight patients (56 %) had pathological findings on myocardial scintigraphy. Fourteen individuals showed evidence of small-vessel disease (cardiac syndrome X). Other comorbidities included obesity, arterial hypertension, nicotine and alcohol abuse, as well as elevated CRP levels. Frequencies largely corresponded to those reported in the recent literature. There was no significant correlation between the severity of psoriasis or any comorbidities and pathological findings on myocardial scintigraphy.

CONCLUSIONS

Myocardial scintigraphy seems to be a very sensitive, noninvasive method for the early detection of cardiac comorbidities in psoriasis patients. However, determining its true diagnostic value will require larger studies with control subjects and control methods such as coronary angiography.

Opium addiction as an independent risk factor for coronary microvascular dysfunction: A case-control study of 250 consecutive patients with slow-flow angina

BACKGROUND

Approximately 20% to 30% of patients who undergo coronary angiography for assessment of typical cardiac chest pain display microvascular coronary dysfunction (MCD). This study aimed to determine potential relationships between baseline clinical characteristics and likelihood of MCD diagnosis in a large group of patients with stable angina symptoms, positive exercise test and angiographic ally normal epicardial coronary arteries.

MATERIAL AND METHODS

This cross-sectional study included 250 Iranian with documented evidence of cardiac ischemia on exercise testing, class I or II indication for coronary angiography, and either: (1) angiographically normal coronary arteries and diagnosis of MCD with slow-flow phenomenon, or (2) normal angiogram and no evidence of MCD. All patients completed a questionnaire designed to capture key data including clinical demographics, past medical history, and social factors. Data was evaluated using single and multivariable logistic regression models to identify potential individual patient factors that might help to predict a diagnosis of MCD.

RESULTS

125 (11.2% of total) patients were subsequently diagnosed with MCD. 125 consecutive control subjects were selected for comparison. The mean age was similar among the two groups (52.38 vs. 53.26%, p=ns), but there was a higher proportion of men in the study group compared to control (42.4 vs. 27.2%, p=0.012). No significant relationships were observed between traditional cardiovascular risk factors (diabetes, hypertension, and dyslipidemia) or body mass index (BMI), and likelihood of MCD diagnosis. However, opium addiction was found to be an independent predictor of MCD on single and multivariable logistic regression model (OR=3.575, 95%CI: 1.418-9.016; p=0.0069).

CONCLUSIONS

We observed a significant relationship between opium addiction and microvascular angina. This novel finding provides a potential mechanistic insight into the pathogenesis of MCD with slow-flow phenomenon.

Quantitative myocardial perfusion imaging in a porcine ischemia model using a prototype spectral detector CT system

We optimized and evaluated dynamic myocardial CT perfusion (CTP) imaging on a prototype spectral detector CT (SDCT) scanner. Simultaneous acquisition of energy sensitive projections on the SDCT system enabled projection-based material decomposition, which typically performs better than image-based decomposition required by some other system designs. In addition to virtual monoenergetic, or keV images, the SDCT provided conventional (kVp) images, allowing us to compare and contrast results. Physical phantom measurements demonstrated linearity of keV images, a requirement for quantitative perfusion. Comparisons of kVp to keV images demonstrated very significant reductions in tell-tale beam hardening (BH) artifacts in both phantom and pig images. In phantom images, consideration of iodine contrast to noise ratio and small residual BH artifacts suggested optimum processing at 70 keV. The processing pipeline for dynamic CTP measurements included 4D image registration, spatio-temporal noise filtering, and model-independent singular value decomposition deconvolution, automatically regularized using the L-curve criterion. In normal pig CTP, 70 keV perfusion estimates were homogeneous throughout the myocardium. At 120 kVp, flow was reduced by more than 20% on the BH-hypo-enhanced myocardium, a range that might falsely indicate actionable ischemia, considering the 0.8 threshold for actionable FFR. With partial occlusion of the left anterior descending (LAD) artery (FFR < 0.8), perfusion defects at 70 keV were correctly identified in the LAD territory. At 120 kVp, BH affected the size and flow in the ischemic area; e.g. with FFR ≈ 0.65, the anterior-to-lateral flow ratio was 0.29 ± 0.01, over-estimating stenosis severity as compared to 0.42 ± 0.01 (p < 0.05) at 70 keV. On the non-ischemic inferior wall (not a LAD territory), the flow ratio was 0.50 ± 0.04 falsely indicating an actionable ischemic condition in a healthy territory. This ratio was 1.00 ± 0.08 at 70 keV. Results suggest that projection-based keV imaging with the SDCT system and proper processing could enable useful myocardial CTP, much improved over conventional CT.

Differences in coronary artery blood velocities in the setting of normal coronary angiography and normal stress echocardiography

Background

Normal left anterior descending (LAD) coronary artery as determined by coronary angiography is considered not only to reflect normal angiography but also to correlate with normal anatomy and function. However, subjects who undergo coronary angiography may differ from those who do not need to have invasive evaluation even if their functional noninvasive studies like dobutamine stress echocardiography (DSE) were normal.

Aim

LAD velocities in subjects with normal angiography and those with normal DSE are equal.

Methods

A total of 244 subjects were evaluated, 78 had normal LAD by angiography and 166 had normal LAD by DSE. All had Doppler sampling of LAD velocities by transthoracic echocardiography.

Results

Velocity was higher in the angiographic subgroup in diastole 41 ± 23 vs 33 ± 14 cm/s, p = 0.0078; systole 18 ± 14 vs 13 ± 7 cm/s, p = 0.012; diastolic integral 12.6 ± 5 vs 9.8 ± 3.8 cm, p = 3.15 × 10^-5; systolic velocity integral 4 ± 2.9 vs 2.8 ± 1.9, p = 0.0014. While heart rate was similar in both groups, the product of diastolic velocity integral and heart rate of the LAD in the angiographic group was higher: 902 ± 450 vs 656 ± 394, p = 0.00599. Diastolic velocity deceleration time was similar in both groups. Coronary flow reserve defined as diastolic velocity ratio before and immediately after DSE correlated negatively with baseline velocity, r = -0.4.

Conclusions

Mode of defining normality of coronary artery affects velocity behavior of the vessel, reflecting functional differences possibly related to microvasculature and vasodilatation.

Assessment of the left ventricular systolic function in cardiac syndrome X using speckle tracking echocardiography

OBJECTIVE

The aim of this study was to evaluate left ventricular (LV) systolic strain by speckle tracking echocardiography (STE) and real-time three-dimensional echocardiography (3-DE) for the early detection of myocardial dysfunction in patients with cardiac syndrome X (CSX).

METHODS

We compared 34 patients with CSX (18 females, mean age 47.9±10.0 years) with 41 healthy persons as a control group (23 females, mean age 50.6±9.9 years). Inclusion criteria for CSX were typical angina, a positive exercise ECG stress test, and angiographically documented normal coronary arteries. Exclusion criteria for both groups were hypertension, valvular heart disease, cardiomyopathies, inflammatory diseases, myocarditis, vasculitis, arthropathies, Tietze's syndrome, gastrointestinal diseases, aortic diseases, hormone replacement therapy, arrhythmias, liver diseases, and alcohol use. All subjects underwent two-dimensional STE and 3-DE to assess resting LV function. STE measures were taken from the basal septum, mid-septum, apical septum, apex, apicolateral, mid-lateral, basal lateral, anteroseptal, anterior, anterolateral, inferolateral, inferior, and inferoseptal walls. Student's t-test, Mann-Whitney U test, and chi-square test were used to statistically analyze data.

RESULTS

LV echo ejection fraction (EF) and systolic wave peak velocity were similar for both groups. Regional mean longitudinal strain (-17.7±2.5% vs. -19.8±1.8%; p<0.0001) was significantly lower in patients with CSX than in healthy control patients. However, regional mean circumferential strain values (-22.0±1.6% vs. -22.2±2.3%; p=0.78) did not differ significantly between the two groups.

CONCLUSION

Significant impairment of LV longitudinal myocardial systolic function was detected with STE in patients with CSX, although normal 3-D EF and tissue Doppler imaging systolic parameters were observed. Arteriosclerosis of small coronary arteries and microvascular dysfunction may affect myocardial longitudinal strain.

Sex-specific factors in microvascular angina

In women presenting for evaluation of suspected ischemic symptoms, a diagnosis of normal coronary arteries is 5 times more common than it is in men. These women are often labelled as having cardiac syndrome X, and a subset of them have microvascular angina caused by microvascular coronary dysfunction (MCD). MCD is not benign and is associated with an annual 2.5% cardiac event rate. Noninvasive testing for MCD remains insensitive, although newer imaging modalities, such as adenosine cardiac magnetic resonance imaging, appear promising. The gold standard for diagnosis of MCD is coronary reactivity testing, an invasive technique that is not available in many countries. With regard to treatment, large-scale trials are lacking. Although research is ongoing, the current platform of therapy consists of antiangina, antiplatelet, and endothelium-modifying agents (primarily angiotensin-converting enzyme inhibitors and statins).

Coronary microvascular dysfunction assessed by intracoronary acetylcholine provocation testing is a frequent cause of ischemia and angina in patients with exercise-induced electrocardiographic changes and unobstructed coronary arteries

BACKGROUND

The exercise electrocardiogram (ECG) is a standard examination in patients with suspected coronary artery disease. However, despite a pathologic result, many patients undergoing diagnostic coronary angiography do not have any significant epicardial stenosis. In this study, we assessed the relation between a pathologic exercise ECG and coronary microvascular dysfunction in response to intracoronary acetylcholine (ACh) provocation in patients without any relevant epicardial stenosis.

HYPOTHESIS

Coronary microvascular dysfunction is significantly more often in patients with angina, unobstructed coronary arteries and a pathologic exercise stress test compared to those without pathologic stress test.

METHODS

This study recruited 137 consecutive patients with exertional angina pectoris who underwent diagnostic coronary angiography between September 2008 and April 2011 (68% women; mean age, 63 ± 10 years). In none of the patients was there a stenosis of >50%. All patients underwent an exercise ECG before angiography and intracoronary ACh provocation testing for assessment of coronary vasomotor responses directly after angiography.

RESULTS

The exercise ECG showed an abnormal result in 69 patients (50%; ST-segment depression ≥0.1 mV and/or reproduction of the patient's usual symptoms). The ACh test revealed a coronary vasomotor abnormality (reproduction of the patient's symptoms, ischemic ECG shifts ± diffuse distal vasoconstriction) in 87 patients (64%). Such a result was significantly more often found in patients with a pathologic exercise ECG (50/69 [72%] vs 19/69 [28%], P = 0.034). There were no other statistically significant differences between patients with and those without pathologic exercise ECG.

CONCLUSIONS

Coronary microvascular dysfunction is frequently found in patients with exertional angina pectoris and unobstructed coronary arteries. Such a finding is found significantly more often in presence of a pathologic exercise ECG.

Correlation between Obstructive Sleep Apnea Syndrome and Cardiac Disease Severity

Background. Obstructive sleep apnea (OSA) syndrome is one of the most common respiratory disorders in humans. There is emerging evidence linking OSA to vascular disease, particularly hypertension. The underlying pathophysiological mechanisms that link OSA to cardiovascular diseases such as hypertension, congestive heart failure, and atrial fibrillation are not entirely understood. The aim of this study was to investigate the association of obstructive sleep apnea hypopnea syndrome (OSAHS) with coronary atherosclerotic disease (CAD). Methods. A questionnaire survey based on Berlin questionnaire and Epworth Sleepiness Scale (ESS) was conducted among 406 patients to assess demographic data and the symptoms, such as excessive daytime sleepiness and snoring. Epworth Sleepiness Scale and Berlin questionnaire were completed by all of the patients. Venous blood samples were obtained for biochemical tests. Characteristics of coronary arteries were collected from angiographies' reports. All patients were divided into two groups based on results from Berlin questionnaire: low risk patients for OSA and high risk patients for OSA. Data were analyzed by SPSS software version 13. Results. Mean age of patients was 61.8 ± 10.5. 212 (52.2%) patients were categorized as high risk group for apnea. Also, excessive daytime sleepiness was reported in 186 patients (45.8%). The severity of coronary artery involvement, daytime sleepiness, and electrocardiogram abnormalities was significantly higher in high risk patients for OSA compared with low risk patients. High risk patients had higher level of FBS and LDL and lower level of HDL cholesterol (P < 0.05). Conclusion. Our study found a strong correlation between the number of stenotic vessels and OSA. Based on our findings, OSA can be a predisposing factor for cardiac diseases.

Thermodilution-derived coronary microvascular resistance and flow reserve in patients with cardiac syndrome X

BACKGROUND

Although increased coronary microvascular resistance (CMR), resulting in coronary microvascular dysfunction, is speculated to be responsible for myocardial ischemia in patients with cardiac syndrome X (CSX), it has never been directly demonstrated, and the correlation between CMR and severity of myocardial ischemia has not been elucidated in this setting. This study aimed to ascertain the increased CMR directly and to explore the relationship between CMR and severity of ischemia in patients with CSX.

METHODS AND RESULTS

We studied 18 patients with CSX and 18 age- and sex-matched control subjects. Thermodilution-derived coronary flow reserve and index of microvascular resistance were measured using a pressure-temperature sensor-tipped coronary wire. Exercise treadmill test was performed by the Bruce protocol for calculating Duke treadmill score. Coronary flow reserve was significantly lower (2.37±0.81 versus 3.68±0.72; P<0.001) and index of microvascular resistance was higher (33.1±7.9 versus 18.8±5.6 U; P<0.001) in patients with CSX compared with those in control subjects. The Duke treadmill score was correlated positively to coronary flow reserve (r=0.539; P=0.021) and negatively to index of microvascular resistance (r=-0.742; P<0.001) in patients with CSX.

CONCLUSIONS

Using an intracoronary thermodilution method, we for the first time directly demonstrated an increased microvascular resistance in patients with CSX. Furthermore, severity of ischemia was found to be intimately associated with CMR in this setting.

ω-3 fatty acid treatment in cardiac syndrome X: a double-blind, randomized, placebo-controlled clinical study

OBJECTIVE

We conducted a clinical trial to examine the effect of ω-3 fatty acids in patients with cardiac syndrome X (CSX). We aimed to evaluate the potential impact of ω-3 fatty acids on endothelial function, oxidative stress, and symptom relief in the CSX.

METHODS AND RESULTS

Eighteen patients with CSX were enrolled according to a double-blind, randomized, placebo-controlled design. Patients were randomized to ω-3 fatty acids (1440 mg/day, n=8) or placebo (n=10) for 4 months. We assessed plasma levels of malondialdehyde (MDA), endothelium-dependent vasodilatation [flow-mediated dilatation (FMD)], endothelium-independent vasodilatation [nitroglycerin-mediated dilatation (NMD)], and status of symptom [score with Seattle Angina Questionnaire (SAQ)] before and after the treatment. After 4 months, patients who were treated with ω-3 fatty acids showed significant increases in the FMD (from 47±48 to 104±23%, P<0.05) and NMD (from 51±53 to 93±35%, P<0.05) values, and significant decreases in the plasma MDA levels (4.4±0.86 to 3.35±0.33 µmol/l, P=0.012). SAQ scores were increased significantly in both groups (from 60±14 to 73±15%, P<0.05 placebo, from 67±10 to 81±9%, P<0.05 treatment group). NMD was correlated negatively with the plasma MDA levels.

CONCLUSION

Four months of therapy with a moderate dose of ω-3 fatty acids improved the endothelial function and reduced oxidative stress in patients with CSX.

Reduced survival in patients with "coronary microvascular disease"

The syndrome of chest pain, abnormal stress test, and nonflow limiting coronary artery disease (CAD) is common and is attributed to coronary microvascular disease (µVD). It is associated with increased hospital admissions and health care costs. But its impact on long-term survival is not known. Of the 9941 consecutive patients who had an exercise stress test for evaluation of chest pain between May 1991 and July 2007, 935 had both a positive stress test and a coronary angiogram within 1 year of their stress test forming the study cohort. Significant angiographic CAD defined as ≥70% stenosis of an epicardial coronary artery or ≥50% stenosis of the left main coronary artery was present in 324 patients. Rest (n = 611) were considered to have coronary µVD. Compared with patients with significant epicardial CAD, patients with coronary µVD were younger (63 ± 11 vs. 65 ± 10 years, p = 0.002), and had lower left ventricular wall thickness (p < 0.02), systolic blood pressure (BP; p = 0.002), pulse pressure (0.0008), systolic BP with exercise (p = 0.0001), and pulse pressure with exercise (p < 0.0001). Those with coronary µVD had a better survival compared with those with significant epicardial CAD, but worse than that expected for age- and gender-matched population (p < 0.0001). Coronary µVD as a cause of chest pain and positive stress test is common. All-cause mortality in patients with coronary µVD is worse than in an age- and gender-matched population control, but better than those with significant epicardial CAD.