Cardiac syndrome X and endothelial dysfunction: new concepts in prognosis and treatment

Typical Exertional Angina With No Angiographic Coronary Artery Disease

Cardiac syndrome X (CSX) is a cardiac condition that is a diagnosis of exclusion. Patients usually present with terrible chest pains suggestive of myocardial infarction, but angiogram imaging shows no occlusion in the coronary vessels that would be suggestive of coronary artery disease. CSX is more commonly seen in women, but this case report demonstrates a different clinical presentation of CSX in a young, otherwise healthy male patient. The 38-year-old male patient presented to the emergency room with chest discomfort radiating to the left arm and to the left jaw. The chest pain started after the patient went for a jog, with the pain lasting for a couple of hours. The electrocardiogram (ECG) was abnormal, showing nonspecific ST changes and unremarkable troponin levels. The patient underwent a coronary angiogram, which was unremarkable. Three years later, the patient presented once more with chest heaviness that occurred again after going for a run. The patient's troponins were unremarkable, and an ECG test showed a new onset of AV block. Due to the ongoing chest pain, the patient received another coronary angiogram. This showed that the coronary vessels had no indications of occlusion. The patient was discharged and scheduled to follow up with their cardiologist for an extensive discussion about medications for their condition. This case report should bring awareness of the classical presentation of this disease in an uncommon population group and a way to identify this syndrome once exclusions have been made on previous hospitalizations.

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.

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.

Five-Year Follow-Up of Coronary Microvascular Dysfunction and Coronary Artery Disease in Systemic Lupus Erythematosus: Results From a Community-Based Lupus Cohort

OBJECTIVE

The present study was undertaken to investigate prospective change in the prevalence of coronary microvascular dysfunction (CMD) and obstructive coronary artery disease (CAD) in a cohort of subjects with systemic lupus erythematosus (SLE) initially evaluated for anginal chest pain (CP). Prior work documented a relatively high prevalence of CMD in the absence of obstructive CAD in subjects with SLE.

METHODS

Twenty female SLE subjects with CP who underwent stress cardiac magnetic resonance imaging (CMRI) and coronary computed tomography angiography at baseline were reevaluated at 5 years.

RESULTS

Seventeen subjects (85%) were available and reenrolled, of which 11 (65%) had persistent CP at follow-up. Fourteen subjects had complete follow-up CMRI, of which 36% (n = 5) demonstrated CMD at follow-up. Further, 25% (1 of 4) of the originally abnormal myocardial perfusion reserve index (MPRI) findings at baseline were lower at follow-up, while 2 additional abnormal MPRI findings at follow-up were noted in previously normal MPRI results. The prevalence of CMD and nonobstructive/obstructive CAD both was unchanged between baseline and follow-up, respectively (both P values not significant). During follow-up, 33% of subjects (5 of 15) had adverse cardiac outcomes, including pericarditis, unstable angina, or intracranial aneurysm clipping procedure.

CONCLUSION

At the 5-year follow-up of SLE subjects with CP who were evaluated at baseline and follow-up, a majority had persistent CP, and nearly one-half had similar or worse myocardial perfusion consistent with CMD without obstructive CAD. These findings propose an alternative explanation for CP in SLE subjects compared to the more common SLE-related accelerated obstructive CAD accounting for CP and adverse outcomes. These findings support further studies of CMD as an etiology for cardiac morbidity and mortality in SLE.

Echocardiographic measurement of epicardial adipose tissue thickness in patients with microvascular angina

Introduction

Impaired coronary microcirculation, inflammation, and endothelial dysfunction were reported etiological factors for microvascular angina (MVA). Recently, increased epicardial adipose tissue (EAT) thickness has been associated with hypertension, metabolic syndrome, and coronary artery disease in general population. In this study, we aimed to evaluate the EAT thickness in patients with MVA.

Methods

This study enrolled 200 patients (83 males; mean age: 55.4 ± 8.2 years) who have been diagnosed with MVA and 200 controls (89 males; mean age: 54.4 ± 8.5 years). All patients underwent transthoracic echocardiography, and EAT thickness was measured from a parasternal long-axis view as the hypoechoic space on the right ventricular free wall.

Results

The mean EAT thickness was significantly higher in MVA patients than the controls (5.5 ± 1.1 vs. 4.9 ± 0.7 mm; p < 0.001). Multiple logistic regression analysis showed that increased EAT thickness was an independent predictor of MVA (OR = 1.183, 95% CI = 1.063-1.489; p = 0.023). In receiver operating characteristic curve analyses, EAT thickness above 5.3 mm predicted MVA with a sentivity of 68% and a specificity of 63% (AUC = 0.711, 95% CI = 0.659-0.762; p < 0.001).

Conclusions

The EAT thickness was observed significantly higher in MVA patients as compared to controls. Increased EAT thickness may be associated with mechanisms that play a major role in the pathogenesis of MVA.

NONOBSTRUCTIVE CORONARY ARTERY DISEASE - CLINICAL RELEVANCE, DIAGNOSIS, MANAGEMENT AND PROPOSAL OF NEW PATHOPHYSIOLOGICAL CLASSIFICATION

SUMMARY – New data gathered from large clinical trials indicate that nonobstructive coronary artery disease (non-CAD) is a clinical entity that should not be ignored. It is estimated that 50% of female population undergoing coronarography are diagnosed with non-CAD. There is also an increase in the prevalence of non-CAD in both genders, which is probably due to gradual expanding of clinical indications for angiography in patients with angina. Furthermore, considering the increased mortality risk established recently, a prognosis of non-CAD is not benign as previously thought. However, the concept and definition of non-CAD remains elusive causing difficulties in diagnosis and treatment. One of the major shortcomings is the exclusion-based diagnosis of non-CAD. Furthermore, treatment of non-CAD still presents a great challenge and optimal therapy is yet to be determined. There are two major hypotheses explaining the pathophysiological mechanisms of non-CAD, i.e. ischemic hypothesis based on abnormal microvascular dysfunction and non-ischemic one based on altered pain perception. This review encompasses a broader spectrum of pathophysiological mechanisms of non-CAD, and proposes a new way of classification based on the major disorder involved: type I (ischemic mechanisms) and type II (non-ischemic mechanisms), depending on which mechanism predominates. Hopefully, this would provide new insights in the understanding of this disorder, thus leading to accurate and early diagnosis and successful treatment, especially considering the increased mortality risk in these patients.

The prognostic value of asymmetric dimethylarginine in patients with cardiac syndrome X

Background

The pathophysiology of cardiac syndrome X is multifactorial and endothelial dysfunction has been implicated as important contributing factor. Asymmetric dimethylarginine (ADMA), characterized as a circulating endogenous inhibitor of nitric oxide synthase, may have been implicated as an important contributing factor for the development of endothelial dysfunction. In this study, we aim to assess the predictive power of ADMA for long-term prognosis in patients with cardiac syndrome X.

Methods and results

We enrolled 239 consecutive patients with cardiac syndrome X diagnosed by coronary angiography. The mean age was 58.7±10.1 years. The patients were grouped into tertiles according to the plasma ADMA levels: <0.38 μmol/l (tertile I), 0.38–0.44 μmol/l (tertile II), and >0.44 μmol/l (tertile III). All patients were followed up for a mean period of 6.5±1.5 years (median: 6.3 years, inter-quartile range: 5.7–8.0 years). During the follow-up period, major adverse events (MAE) were observed in 15 patients (6.3%), including 13 deaths. The plasma ADMA levels in patients who developed MAE were significantly higher than those who did not (0.48±0.06 μmol/l vs. 0.42±0.08 μmol/l, p = 0.005). In multivariate Cox regression analysis adjusted for age, eGFR and LVEF, ADMA tertile I and II were identify to be associated with a significantly lower risk of MAE compared to ADMA tertile III (p = 0.017). By considering the plasma ADMA level as a continuous variable, the plasma ADMA level remained a significant independent predictor for outcomes of MAE, and the relative risk of MACE increased by 50% when plasma ADMA level increased by 1 SD of value (p = 0.018).

Conclusions

In patients with cardiac syndrome X, elevated plasma ADMA levels appeared to be an independent predictor of long-term adverse clinical outcomes.

Association of Inflammation and Endothelial Dysfunction with Coronary Microvascular Resistance in Patients with Cardiac Syndrome X

Background

Although a proportion of CSX patients have impaired brachial artery flow-mediated dilatation (FMD) in response to hyperemia, suggesting that endothelial dysfunction in these patients may be systemic and not just confined to the coronary circulation; the underlying mechanisms triggering endothelial dysfunction in these patients are still incompletely understood.

Objectives

To assess the association of the index of Microcirculatory Resistance (IMR) with endothelial dysfunction and inflammation in patients with CSX.

Methods

We studied 20 CSX patients and 20 age and gender-matched control subjects. Thermodilution-derived coronary flow reserve (CFR) and IMR were measured using a pressure-temperature sensor-tipped guidewire. Brachial artery FMD was measured using high-resolution, two-dimensional ultrasound images obtained with a Doppler ultrasound device (HDI-ATL 5000, USA) with a 5 MHz to 12 MHz linear-array transducer.

Results

Compared with in control subjects, CFR was significantly lower (2.42 ± 0.78 vs. 3.59 ± 0.79, p < 0.001); IMR was higher (32.2 ± 8.0 vs. 19.5 ± 5.5, p < 0.001); the concentration of hs-CRP and FMD was higher (4.75 ± 1.62 vs. 2.75 ± 1.50; 5.24 ± 2.41 vs. 8.57 ± 2.46, p < 0.001) in CSX patients. The Duke treadmill score (DTS) was correlated positively to CFR and FMD (0.489 and 0.661, p < 0.001), it was negative to IMR and hsCRP (-0.761 and -0.087, p < 0.001) in CSX patients.

Conclusions

The main finding in this study is that the DTS measured in patients with CSX was associated to hsCRP and FMD. Moreover, the independent effects of exercise tolerance can significantly impair FMD and hsCRP in CSX patients; especially it is particularly important to whom where FMD was associated negatively with IMR.

Serum endocan levels in patients with cardiac syndrome X

BACKGROUND

Endocan is a recently introduced marker of endothelial dysfunction and is also associated with inflammation and atherosclerosis. To date, the relationship between cardiac syndrome X (CSX) and endocan has not been studied. The objective of this study was to compare the serum endocan levels of patients with CSX with those of control subjects.

PATIENTS AND METHODS

In this study, 50 patients were included in the CSX group and 28 patients in the control group. Patients with pathological conditions that could potentially influence endothelial functions were excluded. Endocan serum concentrations were measured using an enzyme-linked immunosorbent assay.

RESULTS

The mean endocan level of the CSX group was significantly higher than that of the control group (3051.3 ± 1900.5 ng/l vs. 2088.1 ± 522.2 ng/l; p = 0.002). There was no difference between the two groups in terms of age, gender, hypertension, diabetes mellitus, dyslipidemia, and smoking status. In receiver operating characteristic (ROC) curve analysis, endocan levels greater than 2072 ng/l had a 72% sensitivity and 54% specificity (p = 0.002) for accurately predicting a diagnosis of CSX.

CONCLUSION

The results of this study suggest that patients with CSX have higher endocan levels. Therefore, endocan may be valuable in helping uncover the underlying pathogenesis of CSX.

Investigation of MTHFR gene C677T polymorphism in cardiac syndrome X patients

BACKGROUND

Definition of Cardiac Syndrome X (CSX) refers to groups of patients with positive exercise stress test and normal epicardial coronary arteries on coronary angiography accompanied by chest pain. Although the etiology of CSX is not completely understood, there is a common consensus that its pathophysiology may be associated with endothelial dysfunction resulting in impaired coronary flow. Some polymorphisms observed on the MTHFR gene cause inactivation of the MTHFR enzyme, leading to hyperhomocysteinemia and homocysteinuria, which are prominent risk factors of cardiovascular and cerebrovascular diseases. It was aimed to explain the association of the endothelial dysfunction, which is thought to play a role in the pathophysiology of CSX, with C677T polymorphism on MTHFR gene based on genetic basis.

METHODS

A total of 176 CSX patients and 196 healthy subjects with similar age and clinical features were compared in terms of C677T polymorphism of the MTHFR gene.

RESULTS AND CONCLUSION

There was no significant difference in terms of MTHFR gene C677T polymorphism between CSX patients and controls. When genotypic distribution was compared based on gender in both patients and controls, no significant difference was found between male and female subjects (P>.05). As fasting blood sugar and urea values were significantly higher, alanine aminotransferase and gamma-glutamyl transferase levels were significantly lower in the patients than the controls (P<.05). Described family story of the patients was significantly higher than the controls (P<.05). These suggest that homocysteine metabolism in CSX is not directly related to the endothelial dysfunction and thus the effect on the microvascular circulation.

Left atrial volume and function in patients with cardiac syndrome X assessed by real time three-dimensional echocardiography

OBJECTIVE

The aim of this study was to evaluate left atrial (LA) volume and function using real time three-dimensional echocardiography (RT3DE) in patients with cardiac syndrome X (CSX).

METHODS

Fifty patients with CSX (28 females; mean age 50.9±10.9 years) and 50 age- and gender-matched healthy controls (30 females; mean age 52.3±9.8 years) who had negative treadmill exercise test and normal coronary arteries on invasive coronary angiography were included in the study. Comprehensive two-dimensional (2D), pulsed and tissue Doppler, speckle tracking echocardiography, and RT3DE for the assessment of LA dynamics were performed in all study participants.

RESULTS

Cardiac syndrome X and control groups have similar clinical characteristics regarding age, sex, body mass index, hypertension, diabetes, and smoking habit. 2D echocardiographic parameters were also similar between groups. Pulsed- and tissue Doppler parameters, IVRT, A, and A_m values, were higher in CSX group, while E_m , E/A, and E_m /A_m ratios were higher in the control group reflecting mild diastolic dysfunction. Regarding RT3DE parameters, LA maximum volume, minimum volume, volume before atrial contraction, LA maximum volume index, total and active stroke volumes were found to be increased in CSX patients. However, LA total stroke fraction, passive stroke volume, passive stroke fraction, peak systolic, and diastolic longitudinal strains were found to be lower in CSX patients.

CONCLUSION

The main finding of this study was that CSX patients had altered LA booster pump, reservoir, and conduit functions. This finding may have clinical implications for early detection of abnormal LA dynamics in CSX patients.

Association of endothelial dysfunction and cytotoxin-associated gene A-positive Helicobacter pylori in patients with cardiac syndrome X

Background

Existence of coronary endothelial dysfunction has been demonstrated in patients with cardiac syndrome X (CSX). In addition, Helicobacter pylorus (H. pylori) has been associated with CSX. We aimed to assess the possible association of endothelial dysfunction and cytotoxin-associated gene A-positive H. pylori (CagA+) infection in CSX patients.

Methods

Fifty-six patients with CSX (23 male/33 female; age: 51.25 ± 8.86 years) who were anti-H. pylori IgG-positive [H. pylori(+)] and 24 CSX patients (7 male/17 female; age: 52.79 ± 9.88 years) who were H. pylori(−) were included. Also, anti-H. pylori IgG-positive patients were determined by the presence of IgG antibody to CagA. Levels of endothelin-1 (ET-1), E-selectin and intercellular adhesion molecule-1 (ICAM-1) were measured.

Results

Endothelial dysfunction biomarkers were higher in H. pylori(+) than in H. pylori(−) patients (ET-1: 54.60 ± 25.39 vs. 42.59 ± 18.37 pg/ml, p = 0.04; E-selectin: 42.68 ± 14.26 vs. 31.72 ± 8.26 ng/ml, p = 0.001; ICAM-1: 339.68 ± 135.8 vs. 266.51 ± 125.1 ng/ml, p = 0.02). Among H. pylori(+) subjects, 28 cases were CagA(+) and 28 cases were CagA(−). There were significant differences in measured levels of E-selectin between CagA(+) and CagA(−) groups (48.00 ± 16.37 vs. 37.37 ± 9.37 ng/ml, p = 0.004). For ET-1 and ICAM-1 levels, the difference between CagA(+) and CagA(−) was insignificant (p = 0.174 and p = 0.07, respectively).

Conclusion

High levels of endothelial dysfunction biomarkers are found in CSX patients with anti-CagA(+). These findings suggest the infection with CagA(+) H. pylori strain may play a role as a risk factor in development of CSX through provocation of endothelial dysfunction. Therefore, a long term follow up to investigate the outcomes of these patients is proposed.

Lipid Profile in Cardiac Syndrome X: Association with Helicobacter pylori

INTRODUCTION

Chronic inflammation caused by Helicobacter pylori (H.pylori) infection has a pathogenic role in Cardiac Syndrome X (CSX). In addition, it has shown that bacterial infection may affect blood lipids.

AIM

To assess if H.pylori affects the level of lipid profile in CSX.

MATERIALS AND METHODS

Eighty-eight CSX patients and 97 healthy controls were enrolled. The Total Cholesterol (TC), Triglyceride (TG), Lipoprotein A (LP{A}), Low Density Lipoprotein (LDL), High Density Lipoprotein (HDL), Apoprotein A1 (APOA1), and Apoprotein B (APOB) was estimated colorimetrically. In addition, the presence of IgG antibody to H.pylori was tested in plasma samples by using enzyme linked immunosorbent assay method.

RESULTS

TC, LP{A}, LDL, APOA1 and APOB levels in CSX group were significantly higher than those of the control group (p<0.05). But, these parameters in H.pylori positive and H.pylori negative, among CSX and control groups were not significant.

CONCLUSION

Increased plasma level of lipid profile and H.pylori infection were associated with CSX; it seems that plasma lipid disorders have a significant role in the development of CSX.

Fragmented QRS frequency in patients with cardiac syndrome X

Objective:

Cardiac syndrome X (CSX) is characterised by typical exertional chest pain, a positive response to exercise testing, and a normal coronary angiography. The relationship of CSX with myocardial fibrosis and ischemia has been clearly demonstrated in previous studies. In addition, fragmented QRS (fQRS) has been reported in the literature as an indicator of myocardial fibrosis. The aim of this study was to investigate the frequency of fQRS in patients with CSX.

Methods:

This prospective case-control study included 37 patients (CSX group) with typical complaints of angina, ischemia on an exercise test, and normal coronary arteries as detected by angiography and 47 patients (control group) with normal coronary arteries. Echocardiographic examinations were performed according to the recommendations of the American Society of Echocardiography. Continuous variables were expressed as mean±standard deviation (SD), and the qualitative variables were expressed as a percentage or ratio. Data were compared statistically with Shapiro–Wilk test, Student’s t-test, Mann-Whitney U, chi-square and Fisher exact test.

Results:

There was no significant difference between the CRX and control groups with respect to basic characteristics such as age and sex. fQRS and the frequency of its presentation with stable angina pectoris at the clinic were significantly higher in the CSX group than in the control group (p values: 0.001 and <0.001, respectively).

Conclusion:

A close follow-up would be useful in CSX patients in whom fQRS is detected in an electrocardiogram (ECG) because of the association between fQRS and poor prognosis with respect to the prevention of late complications. We believe that the presence of fQRS in the ECG aids in the diagnosis of CSX in clinical practice and in the recognition of this group of patients. (Anatol J Cardiol 2016; 16: 616-20)

The usefulness of plateletcrit to predict cardiac syndrome X in patients with normal coronary angiogram

Introduction

Cardiac syndrome X (CSX) is a clinical entity defined as the triad of typical angina pectoris on exercise, electrocardiographic or metabolic findings of ischemia and normal epicardial coronary arteries. Platelets, whose amount in the blood is indicated with plateletcrit (PCT), play an important role in inflammatory and thrombotic processes and the physiopathology of cardiovascular events.

Aim

To investigate the association between cardiac syndrome X and PCT and platelet count.

Material and methods

A total of 113 patients with normal coronary angiogram were included in the study. Fifty patients with typical chest pain and evidence of myocardial ischemia in non-invasive tests formed the CSX patient group. The control group consisted of 63 age- and gender-matched patients with normal coronary arteries but without angina.

Results

The mean PCT value of the CSX group was significantly higher than that of the control group (0.22 ±0.06 vs. 0.19 ±0.04; respectively, p=0.03). Higher PCT was found to be associated with the presence of CSX in patients with normal coronary arteries by multivariate logistic regression analysis.

Conclusions

We suggest that high PCT may predict the presence of cardiac syndrome X in patients with normal coronary arteries. The value of PCT appears additive to conventional expensive methods commonly used in CSX prediction.

Diagnosis of coronary microvascular dysfunction - Present status

Definite clinical diagnosis of microvascular angina is not possible with the existing knowledge. Resting electrocardiogram may be normal, and exercise electrocardiogram may be unremarkable. Echocardiography usually does not show regional wall motion abnormalities. Transthoracic Doppler echocardiography can satisfactorily evaluate only left anterior descending coronary artery and that too in some patients. Radio-isotope imaging can detect only severe localized disease. Noninvasive diagnosis needs high index of suspicion. At present, definite diagnosis is based on documentation of normal epicardial coronaries, coronary flow reserve less than 2.5 on adenosine induced hyperemia, and absence of spasm of epicardial coronaries on acetylcholine provocation. Invasive evaluation is costly, needs sophisticated equipments and expertise. Therapeutic and prognostic implications of various parameters remains to be evaluated. At present invasive evaluation is recommended only for patients with intractable symptoms with unconfirmed diagnosis, requiring repeated hospitalization and evaluation with failure of empirical therapy.

Frequency of Helicobacter pylori and cytotoxine associated gene A antibodies in patients with cardiac syndrome X

Background:

Cardiac syndrome X (CSX) is a condition in which patients have the pain of angina despite normal coronary angiogram. Recently, Helicobacter pylori (H. pylori) bacteria has been associated with CSX. However, there is no obvious data about the frequency of its virulent strain (cytotoxine associated gene A: CagA) in patients with CSX. We surveyed the frequency of H. pylori and CagA antibodies in patients with cardiac syndrome X and healthy controls.

Materials and Methods:

Plasma samples from 100 CSX patients (61 females and 39 males; mean age: 51.8 ± 12.3 years) and 100 healthy controls (61 females and 39 males; mean age: 48.9 ± 6.3 years) were tested for the presence of IgG antibody to H. pylori using enzyme linked immunosorbent assay (ELISA) method. Also, infected patients were determined by the presence of IgG antibody to CagA by ELISA method. Statistical analysis was carried out using chi-square test and independent samples T-test.

Results:

Ninety two percent (92/100) of patients were anti-H. pylori positive (anti-H. pylori+), while only 56.0% (56/100) of control group were anti-H. pylori+ (P<0.01). However, prevalence of anti-CagA positive (anti- CagA+) in H. pylori infected- CSX patients and control groups were 59.8% (55/92) and 60.7% (34/56), respectively (P>0.05).

Conclusion:

Thus, due to the high frequency of anti-H. pylori in CSX patients, and the probable causative effect of chronic infection in vascular diseases, it is suggested that H. pylori has a probable role in the pathogenesis of CSX.

ABO-Rh blood groups distribution in cardiac syndrome X patients

Background:

Data on frequency distribution of ABO-Rh blood groups in cardiac syndrome X (CSX) patients are not available. We aimed to investigate the distribution of ABO-Rh blood groups in these patients.

Materials and Methods:

A total of 247 CSX patients’ records were reviewed in a cross-sectional study from 2006 to 2010. One hundred forty six patients (59.1%) were female, and the mean patient age was 52 ± 11 years. The frequency of ABO-Rh blood groups was compared to the frequency of these blood groups in the West-Azerbaijan province, Iran; general population.

Results:

Blood groups distribution among CSX patients showed phenotypes A, B, AB, O and Rh negative as 33.1%, 21.9%, 9.3%, 35.8%, and 7.9%, respectively. According to our results, there were no differences in ABO-Rh blood groups distribution between CSX patients and normal population.

Conclusion:

These data suggest that ABO-Rh blood groups might be unassociated with CSX.

Association of inflammation and cytotoxin-associated gene a positive strains of helicobacter pylori in cardiac syndrome x

BACKGROUND

Cardiac syndrome X (CSX) is a condition in which patients have the pain of angina despite normal coronary angiogram. Helicobacter pylori (H. pylori) infection causes chronic inflammation which may play a pathogenic role in CSX. We surveyed the association of inflammation with H. pylori and its virulent strain (cytotoxin-associated gene A positive; CagA+) infections with CSX.

MATERIAL AND METHODS

Sixty patients with CSX (38 women/22 men; mean age: 51.8 ± 12.3) and 60 age- and gender-matched healthy controls (39 women/21 men; mean age: 48.9 ± 6.3) were enrolled. Plasma samples were tested for the presence of IgG antibody to H. pylori using enzyme linked immunosorbent assay (ELISA) method. IgG- positive patients were determined by the presence of IgG antibody to CagA, also by ELISA method. Also, plasma levels of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were measured by ELISA method.

RESULTS

Patients with CSX were detected to have significantly higher plasma IL-6 and TNF-α level in comparison with normal controls (33.6 ± 3.5 vs 3.2 ± 0.4 and 24.2 ± 2.3 vs 3.1 ± 0.4, respectively; p < 0.01). The plasma levels of these inflammatory factors in CgA+ were significantly higher than those in CagA- (CSX: IL-6: 43.05 ± 5.04 vs 23.97 ± 4.58 and TNF-α: 31.43 ± 3.13 vs 16.47 ± 2.93, CONTROLS: IL-6: 3.52 ± 1.39 vs 2.90 ± 0.67 and TNF-α: 5.39 ± 1.17 vs 2.22 ± 0.43, respectively; p < 0.05).

CONCLUSION

The CagA+ strain of H. pylori, can not only be a trigger, and may also have a role via chronic inflammation in the pathogenesis of CSX.

Uric acid level and its association with carotid intima-media thickness in patients with cardiac syndrome X

OBJECTIVE

The aim of our study was to evaluate serum uric acid level and its relationship with carotid intima-media thickness (CIMT) in patients with cardiac syndrome X (CSX).

SUBJECTS AND METHODS

A total of 50 patients with CSX (28 females/22 males, 51.0 ± 10.9 years) and 40 controls (27 females/13 males, 53.0 ± 10.2 years) were included in the study. All subjects underwent a noninvasive stress test and conventional coronary angiography. Serum uric acid levels were measured and B mode ultrasonography was performed to assess CIMT in all subjects.

RESULTS

Serum uric acid levels were higher in patients with CSX than in the control subjects (5.1 ± 1.8 vs. 3.9 ± 1.3 mg/dl; p = 0.002). The CIMT was higher in patients with CSX than in the control subjects (0.75 ± 0.18 vs. 0.63 ± 0.09 mm; p < 0.001). A significant correlation was found between serum uric acid values and CIMT measurements in patients with CSX (r = 0.666, p < 0.001).

CONCLUSIONS

Serum uric acid levels were higher in patients with CSX and elevated serum uric acid levels were associated with carotid atherosclerosis, thereby indicating that elevated serum uric acid levels might contribute to the development of subclinical atherosclerosis in CSX patients.

Microvascular coronary dysfunction in women: pathophysiology, diagnosis, and management

Women exhibit a greater symptom burden, more functional disability, and a higher prevalence of no obstructive coronary artery disease compared to men when evaluated for signs and symptoms of myocardial ischemia. Microvascular coronary dysfunction (MCD), defined as limited coronary flow reserve and/or coronary endothelial dysfunction, is the predominant etiologic mechanism of ischemia in women with the triad of persistent chest pain, no obstructive coronary artery disease, and ischemia evidenced by stress testing. Evidence shows that approximately 50% of these patients have physiological evidence of MCD. MCD is associated with a 2.5% annual major adverse event rate that includes death, nonfatal myocardial infarction, nonfatal stroke, and congestive heart failure. Although tests such as adenosine stress cardiac magnetic resonance imaging may be a useful noninvasive method to predict subendocardial ischemia, the gold standard test to diagnose MCD is an invasive coronary reactivity testing. Early identification of MCD by coronary reactivity testing may be beneficial in prognostication and stratifying these patients for optimal medical therapy. Currently, understanding of MCD pathophysiology can be used to guide diagnosis and therapy. Continued research in MCD is needed to further advance our understanding.

Angina in Women without Obstructive Coronary Artery Disease

Angina in the absence of obstructive coronary artery disease, sometimes referred to as cardiac syndrome X (CSX), is a debilitating condition that disproportionately affects women. More than 50% of women evaluated for angina have non-obstructive disease by cardiac catheterization, although the total numbers of women affected by CSX are unknown. Varying clinical definitions and the lack of large scale epidemiologic studies focusing on this illness have resulted in limited knowledge about its risk factors, although there appears to be an association with black race, estrogen deficiency, and insulin resistance. Contrary to prior beliefs about the benign nature of this entity, these women suffer considerable morbidity with costly economic implications that approach the lifetime costs of healthcare utilization for those with obstructive coronary disease. Two prevailing hypotheses have emerged to explain CSX: the ischemic hypothesis detailing abnormal coronary microvascular function and the non-ischemic hypothesis describing altered pain perception and myocardial hypersensitivity. Treatment strategies have focused on both of these pathways with the main goal of improving symptoms. Beta blockers provide the most convincing evidence for benefit, with other antianginals having secondary roles. Other promising pharmacologic therapies include xanthine derivatives, estrogen replacement therapy, ACE inhibitors, and statin medications, among other emerging treatment options. Neurostimulation and lifestyle factors including exercise can also be beneficial in reducing symptoms. However, managing patients with CSX can be frustrating for both patients and physicians, as there is a lack of data regarding an optimal treatment algorithm including few large-scale randomized controlled trials to clarify effective therapies.

Myocardial ischemia in the absence of obstructive coronary artery disease in systemic lupus erythematosus

OBJECTIVES

the purpose of this study was to evaluate the presence of myocardial ischemia measured by adenosine stress cardiac magnetic resonance (CMR) using visual myocardial perfusion and a quantitative myocardial perfusion reserve index (MPRI) in the absence of obstructive coronary artery disease (CAD) in women with systemic lupus erythematosus (SLE) with anginal chest pain (CP).

BACKGROUND

ischemic heart disease is a leading cause of morbidity and mortality in SLE. Previous studies demonstrated the presence of perfusion defects using adenosine stress CMR in patients with CP and no obstructive CAD, consistent with microvascular coronary dysfunction in patients without SLE.

METHOD

Twenty female SLE patients with typical and atypical anginal CP were prospectively enrolled. Patients with established cardiovascular disease were excluded. CMR was performed with 0.05 mmol/kg gadolinium adenosine stress first-pass perfusion in SLE patients and in 10 asymptomatic reference control women. SLE patients also underwent 64-slice coronary computed tomography angiography. CMR was scored visually and quantitatively (MPRI).

RESULTS

among 18 patients with complete data, no patient had obstructive CAD; however, 8 of 18 (44%) displayed visual perfusion defects on stress CMR compared with 0 in 10 control subjects (p = 0.014). The mean MPRI in patients versus controls was 2.0 ± 0.4 versus 2.4 ± 0.4 (p = 0.031) in the subepicardium and 1.8 ± 0.3 versus 2.1 ± 0.4 (p = 0.24) in the subendocardium. Multivariate linear regression revealed that SLE was the only predictor of subepicardial (p < 0.0025; β = -1.059) and subendocardial (p < 0.05; β = -0.529) MPRIs.

CONCLUSIONS

we observed a 44% prevalence of abnormal stress myocardial perfusion by CMR in the absence of obstructive CAD in SLE patients with anginal CP. Compared with controls, reduced MPRI was observed in SLE patients, and SLE presence was a significant predictor of an abnormal MPRI. These findings are consistent with the hypothesis that anginal CP in SLE patients without obstructive CAD is due to myocardial ischemia potentially caused by microvascular coronary dysfunction. Further research in a larger SLE population is warranted.

Chest pain with angiographic clear coronary arteries: A provider's approach to cardiac syndrome X

PURPOSE

To present information about cardiac syndrome X (CSX) including its (a) definition, (b) etiology and pathology, (c) epidemiology, (d) symptomatology, (e) diagnosis, (f) treatment, and (g) prognosis. Clinical recommendations will also be presented.

DATA SOURCES

Articles used in this review were found by searching CINAHL, Medline, the Cochrane Library, Web of Science (ISI), Academic Search Premier, and Health Source: Nursing/Academic Edition.

CONCLUSIONS

The causes of CSX remain unknown; however, CSX is easy to diagnose and can be treated. Medication therapy and risk factor modification can greatly improve the quality of life by decreasing pain occurrence and lessening pain intensity.

IMPLICATIONS FOR PRACTICE

Too often, providers reassure patients of a healthy heart because of normal coronary arteries despite persistent chest pain and ST segment changes on the electrocardiogram. Chest pain, one of the primary signs and symptoms of CSX, can be reduced through common medications and interventions if the diagnosis of CSX is initiated.

Takotsubo cardiomyopathy: a unique cardiomyopathy with variable ventricular morphology

Takotsubo cardiomyopathy is an important differential diagnosis of acute coronary syndrome. It is characterized by normal (or near-normal) coronary arteries, regional wall motion abnormalities that extend beyond a single coronary vascular bed, and often, a precipitating stressor. Variants of the classical left ventricular apical ballooning, including mid- or basal left ventricular wall motion abnormalities, are increasingly recognized. Takotsubo cardiomyopathy is not rare, and heightened awareness of this unique cardiomyopathy likely will lead to a higher reported incidence. Diagnosis of takotsubo cardiomyopathy has important implications for clinical management at presentation and afterward. The long-term prognosis is generally favorable; however, a small subset has potentially life-threatening complications during the initial presentation. The pathophysiologic mechanism is unknown, but catecholamine excess likely has a central role.

Relationship between L-arginine/asymmetric dimethylarginine, homocysteine, folic acid, vitamin B levels, and coronary artery ectasia

BACKGROUND

Coronary artery ectasia (CAE) is characterized by an abnormal dilatation of the coronary arteries. The ratio of L-arginine/asymmetric dimethylarginine (ADMA) and homocysteine are important factors for endothelial function. In this study, we investigate the ratio of L-arginine/ADMA, homocysteine, and folic acid/vitamin B levels in patients with CAE.

METHODS

Forty patients diagnosed with CAE using coronary angiography were included in the study (24 male; mean age, 56 ± 11 years). The control group consisted of 30 patients who had normal coronary arteries as determined by coronary angiography (11 male; mean age, 54 ± 8 years). The ratio of L-arginine/ADMA and plasma homocysteine was measured using high-performance liquid chromatography.

RESULTS

The L-arginine/ADMA ratio and L-arginine levels were significantly lower in the CAE group compared with the control group (110 ± 27 vs. 149 ± 77, P=0.02 and 157 ± 32 μmol/l vs. 187 ± 59 μmol/l, P=0.02, respectively). Plasma ADMA levels were similar in the two groups. Patients with CAE had higher plasma homocysteine levels (P=0.01). Plasma folic acid, vitamin B6, and vitamin B12 levels were similar between the two groups.

CONCLUSION

This study shows that patients with CAE have a lower L-arginine/ADMA ratio and higher plasma homocysteine levels. These results show a potential relationship between endothelial dysfunction and CAE.

Serum ADMA concentration-- an independent factor determining FMD impairment in cardiac syndrome X

Mechanisms of decreased endogenous vascular reactivity in individuals with cardiac syndrome X (CSX) are not fully understood.

AIM

To evaluate the following serum markers: total nitric oxide (NO), asymmetric dimethylarginine (ADMA), platelet-derived growth factor (PDGF), and to establish their relation to ultrasound indexes of endothelial function and structural remodeling in CSX patients.

METHOD

The study group consisted of 43 CSX patients (mean age: 56.3 +/- 9 years), while the control group included 21 healthy subjects (mean age: 54.86 +/- 6.9 years). The high-resolution ultrasound was performed to measure: flow-mediated vasodilatation (FMD), nitroglycerine-mediated vasodilatation (NMD) and intima-media thickness (IMT) of carotid arteries.

RESULTS

In CSX patients, significantly lower FMD (9.06 +/- 3.2%) and significantly higher IMT (0.667 +/- 0.14 mm) values were observed compared to healthy individuals (17.42 +/- 8.4%, 0.571 +/- 0.2 mm; P < 0.05). Mean total NO serum concentration was significantly higher in the CSX group (48.2 +/- 18.2 micromol/L) as compared to controls (32.1 +/- 1.4 micromol/L; P < 0.0001). There were no differences in serum ADMA and PDGF levels. In CSX patients, FMD values correlated with NO (r = 0.323; P = 0.039) and ADMA (r = -0.387; P = 0.012) serum levels; however, there were no significant correlations between NO and ADMA concentrations.

CONCLUSION

Serum ADMA concentration is the only independent factor determining FMD impairment.

Chest pain without significant coronary stenosis after implantation of sirolimus-eluting stents

We encountered a case of exercise-induced chest pain after the implantation of sirolimus-eluting stents (SESs). She had no history of previous chest pain, and an exercise stress test just after the implantation of the SESs was negative without any symptoms. However, six months after the implantation of the SESs, she began to experience frequent episodes of severe chest pain on effort in spite of there being no significant coronary stenosis. Interestingly, severe coronary vasoconstriction was induced by an intracoronary administration of acetylcholine, and exercise stress testing revealed positive findings with chest pain and ST-T segment depression on ECG. An intensive treatment with two types of calcium channel blockers could readily and completely abolish the exercise-induced chest pain and ST-T segment depression on the ECG. In view of these findings, we presumed that coronary microvessel dysfunction and/or exercise-induced coronary vasoconstriction leading to myocardial ischemia had appeared 6 months after the implantation of the SESs. Although the pathogenesis of this phenomenon could not be completely elucidated, the anatomical and functional abnormalities of the coronary arteries associated with the implantation of the SESs may have been one of the most important mechanisms.

Outcomes in patients with abnormal myocardial perfusion imaging and normal coronary angiogram

A subset of subjects undergoing myocardial perfusion imaging has perfusion abnormalities that are subsequently labeled false positive based on coronary angiography. We evaluated the long-term prevalence of cardiovascular events in these patients. We retrospectively identified 48 patients who had reversible perfusion abnormalities with myocardial perfusion imaging and normal coronary angiography. Patients with known coronary artery disease, left ventricular dysfunction, valvular disease, and cardiomyopathy were excluded. Patient follow-up, conducted for at least 3 (mean interval, 7.4) years from the index myocardial perfusion imaging, was accomplished by a review of medical records and telephone interviews. Study endpoints were cardiovascular events defined as sudden cardiac death, myocardial infarction, percutaneous coronary revascularization, coronary artery bypass grafting, and cerebrovascular or peripheral revascularization. Thirty-one percent (15 of 48) of the patients had cardiovascular events. Six of the 48 patients had coronary events. These patients had abnormal myocardial perfusion imaging and normal coronary angiogram. The time between myocardial perfusion imaging and coronary event was 0.5 to 8.67 years. There was a strong correlation between the regions of original perfusion abnormality and the ultimate coronary ischemia or revascularization. Abnormal findings on myocardial perfusion imaging may predict a higher prevalence of coronary and peripheral vascular events than suggested by a normal coronary angiogram.

Direct isolation, culture and transplant of mouse skeletal muscle derived endothelial cells with angiogenic potential

BACKGROUND

Although diseases associated with microvascular endothelial dysfunction are among the most prevalent illnesses to date, currently no method exists to isolate pure endothelial cells (EC) from skeletal muscle for in vivo or in vitro study.

METHODOLOGY

By utilizing multicolor fluorescent-activated cell sorting (FACS), we have isolated a distinct population of Sca-1(+), CD31(+), CD34(dim) and CD45(- )cells from skeletal muscles of C57BL6 mice. Characterization of this population revealed these cells are functional EC that can be expanded several times in culture without losing their phenotype or capabilities to uptake acetylated low-density lipoprotein (ac-LDL), produce nitric oxide (NO) and form vascular tubes. When transplanted subcutaneously or intramuscularly into the tibialis anterior muscle, EC formed microvessels and integrated with existing vasculature.

CONCLUSION

This method, which is highly reproducible, can be used to study the biology and role of EC in diseases such as peripheral vascular disease. In addition this method allows us to isolate large quantities of skeletal muscle derived EC with potential for therapeutic angiogenic applications.

Plasma asymmetric dimethylarginine and L-arginine levels in patients with cardiac syndrome X

BACKGROUND

Endothelial dysfunction and subsequently impaired microvascular circulation are the leading mechanisms in the development of cardiac syndrome X (CSX). The study evaluated the plasma asymmetric dimethylarginine (ADMA) and L-arginine levels of the patients with CSX and the control group and aimed to determine any relationship between these parameters and epicardial coronary blood flow and myocardial tissue perfusion.

METHODS

The study group consisted of 32 patients (mean age: 52.6+/-9.4 years, 14 men) with typical exertional angina, positive exercise test, and normal coronary arteries diagnosed as CSX. Plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio were compared with the values of the control group, which consisted of 17 age-matched and sex-matched individuals. Concentrations of L-arginine and ADMA were measured by high-performance liquid chromatography. In all the coronary territories, epicardial coronary flow was assessed by thrombolysis in myocardial infarction (TIMI) frame count (TFC) method, and tissue level perfusion, by myocardial blush grade (MBG) method. A MBG score less than 3 was considered an impaired myocardial perfusion, and a MBG score of '3' in all the coronary territories, a normal myocardial perfusion.

RESULTS

The plasma ADMA levels of the study group were higher than those of the control group (0.83+/-0.38 vs. 0.55+/-0.44 micromol/l, P=0.03), whereas plasma L-arginine levels were similar in both groups (70.25+/-21.89 vs. 76.09+/-18.22 micromol/l, P=0.36), resulting in a diminished L-arginine/ADMA ratio in the patients with CSX [82.3 (60.2-128.8) vs. 242.2 (76.7-386.4), P=0.003]. In CSX group, the patients with abnormal myocardial tissue perfusion had increased plasma ADMA levels compared with those with normal tissue perfusion (0.99+/-0.37 vs. 0.69+/-0.34 micromol/l, P=0.02), whereas plasma L-arginine levels were similar in both groups. No correlations were observed between TFC values and plasma ADMA, L-arginine levels, and L-arginine/ADMA ratio. Plasma ADMA levels, however, were negatively correlated with MBG scores (r=-0.349, P=0.014).

CONCLUSION

We have shown for the first time that in the patients with CSX, increased plasma ADMA levels might be associated with impaired myocardial tissue perfusion when assessed by MBG.