Endothelial function and coronary spastic angina

Increased plasma glutamate in non-smokers with vasospastic angina pectoris is associated with plasma cystine and antioxidant capacity

Objectives. Endothelial dysfunction caused by oxidative stress plays an important role in the development of vasospastic angina pectoris (VSAP). Glutamate causes endothelial dysfunction by generating oxidative stress, and it inhibits cystine import into endothelial cells via the cystine/glutamate antiporter (X_C^-), which leads to depletion of antioxidant glutathione. However, whether glutamate and cystine are implicated in the pathogenesis of VSAP remains unclear. We investigated plasma glutamate and cystine levels, oxidative stress markers and antioxidant capacity in non-smoker patients with VSAP to determine whether glutamate and cystine are associated with the development of VSAP. We assessed 49 non-smokers assigned to groups with (n = 27) and without (n = 22) VSAP, and also measured plasma glutamate, cystine, nitrotyrosine, reactive oxygen metabolites and biological antioxidant potential. Results. Plasma glutamate and cystine values were significantly higher in the group with, than without VSAP (59.8 ± 25.7 vs. 43.5 ± 18.7 µmol/L, p = .016 and 35.3 ± 14.2 vs. 25.2 ± 9.1 µmol/L, p = .0056, respectively). Plasma glutamate and cystine values were significantly and positively associated (r = 0.32, p = .027). Levels of the oxidative stress markers nitrotyrosine and reactive oxygen metabolites, and biological antioxidant potential of as a measure of antioxidant capacity, did not significantly differ between the two groups. However, glutamate and biological antioxidant potential values were significantly and negatively associated (r = -0.3, p = .036). Conclusion. Plasma glutamate levels were increased in patients with VSAP who did not smoke, and they were positively associated with plasma cystine and negatively associated with the biological antioxidant potential levels.

Endothelium-dependent contraction: The non-classical action of endothelial prostacyclin, its underlying mechanisms, and implications

Although commonly thought to produce prostacyclin (prostaglandin I₂ ; PGI₂ ) that evokes vasodilatation and protects vessels from the development of diseases, the endothelial cyclooxygenase (COX)-mediated metabolism has also been found to release substance(s) called endothelium-derived contracting factor(s) (EDCF) that causes endothelium-dependent contraction and implicates in endothelial dysfunction of disease conditions. Various mechanisms have been proposed for the process; however, the major endothelial COX metabolite PGI₂ , which has been classically considered to activate the I prostanoid receptor (IP) that mediates vasodilatation and opposes the effects of thromboxane (Tx) A₂ produced by COX in platelets, emerges as a major EDCF in health and disease conditions. Our recent studies from genetically altered mice further suggest that vasomotor reactions to PGI₂ are collectively modulated by IP, the vasoconstrictor Tx-prostanoid receptor (TP; the prototype receptor of TxA₂ ) and E prostanoid receptor-3 (EP3; a vasoconstrictor receptor of PGE₂ ) although with differences in potency and efficacy; a contraction to PGI₂ reflects activities of TP and/or EP3 outweighing that of the concurrently activated IP. Here, we discuss the history of endothelium-dependent contraction, evidences that support the above hypothesis, proposed mechanisms for the varied reactions to endothelial PGI₂ synthesis as well as the relation of its dilator activity to the effect of another NO-independent vasodilator mechanism, the endothelium-derived hyperpolarizing factor. Also, we address the possible pathological and therapeutic implications as well as questions remaining to be resolved or limitations of our above findings obtained from genetically altered mouse models.

Coronary Vasospasm After Dobutamine Stress Echocardiogram Triggered by Esmolol

Dobutamine stress echocardiography (DSE) is a commonly utilized method for coronary artery disease (CAD) diagnosis, and it provides important long-term prognostic information. We report a case of a 53-year-old female with multiple cardiovascular risk factors who underwent DSE for evaluation of underlying CAD. The examination was complicated by wide complex tachycardia and promoted administration of esmolol, which shortly led to ST-segment elevation myocardial infarction (STEMI). Coronary angiography showed complete absence of CAD. Coronary vasospasm was a possible suggested mechanism due to the pharmacologic interaction between beta-blockers and dobutamine on alpha- and beta-adrenergic receptors.

Risk Factors of Periprocedural Bradycardia during Primary Percutaneous Coronary Intervention in Patients with Acute ST-Elevation Myocardial Infarction

Background

Evidence available suggests that periprocedural bradycardia negates the benefit of primary percutaneous coronary intervention (PPCI) and worsens the prognosis of patients with acute ST-elevation myocardial infarction (STEMI).

Objective

To investigate the risk factors of periprocedural bradycardia during PPCI in patients with acute STEMI.

Methods

We enrolled 2,536 acute STEMI patients who had PPCI from November 2007 to June 2018 in Beijing Anzhen Hospital, Capital Medical University. We divided all patients into two groups according to periprocedural bradycardia (preoperative heart rate ≥50 times/min, intraoperative heart rate <50 times/min persistent or transient) during PPCI: periprocedural bradycardia group (434 cases) and control group (2102 cases). We compared demographic, clinical, and angiographic characteristics of the two groups. We analyzed the risk factors of periprocedural bradycardia.

Results

The incident rate was 17.1% (434/2536). Logistic regression analysis showed that the differences between the two groups in no-reflow, the culprit vessel was LAD, using thrombus aspiration devices during operation, gender, completely block of culprit vessel, and intraoperative hypotension were statistically significant (P < 0.05). The area under the receiver operating characteristic curve was 0.8390.

Conclusions

No-reflow, the culprit vessel was not LAD, using thrombus aspiration devices during operation, gender, completely block of culprit vessel, and intraoperative hypotension may be independent risk factors for predicting periprocedural bradycardia during PPCI in patients with acute STEMI. We registered this study with WHO International Clinical Trials Registry Platform (ICTRP) (registration number: ChiCTR1900023214; registered date: 16 May 2019).

Assessing Vessel Tone during Coronary Artery Spasm by Dual-Acquisition Multidetector Computed Tomography Angiography

BACKGROUND

Diminished vascular tone is an established biomarker of heart damage. Little is known about the extent of coronary vessel tone (CVT) with spasm as assessed by dual-acquisition multidetector computed tomography angiography (MCTA) in patients with vasospastic angina (VSA).

OBJECTIVE

We evaluated the CVT modulated by intravenous nitrate injection (INI) using MCTA imaging in VSA patients.

METHODS

Twenty-one VSA patients (60 ± 9 years; 76% males) who underwent initial MCTA (without morning vasodilation), followed by an intracoronary ergonovine provocation test were included. Within 3 days after the initial MCTA patients received INI followed by 28-vessel segment spasm analyzed by MCTA 3D software, applying the following formula as the definition of CVT index (CVTI): (CSAIV nitrate - CSAinitial/CSAIV nitrate) ×100 %, where CSA is the cross-sectional area.

RESULTS

Compared to the initial MCTA measures, the INI provocation resulted in the significant increase of average diameter and CSA at the spasm site (2.60 mm [2.11-3.16] vs. 1.42 mm [1.13-2.13]; 5.37 mm2 [3.67-7.54] vs. 1.62 mm2 [1.02-3.02]; p < 0.001). The CVTI at the spastic segments was higher than at the proximal reference segments (41.0% [21.8-52.3] vs. 18.8% [5.9-26.6] for CVTI diameter; 65.1% [38.6-77.0] vs. 33.9% [5.2-48.1] for CVTI CSA, respectively). To predict VSA, the cut-off value for CVTI diameter was 38.6% (AUC 0.777; 95% CI 0.653-0.901) and 62.5% (AUC 0.779; 95% CI 0.657-0.902) for CVTI CSA in a receiver-operating characteristic curve analysis, with 57.1% sensitivity and 92.9% specificity.

CONCLUSIONS

This novel imaging technique for assessing CVT by dual-acquisition MCTA after applying INI provocation is suitable for the detection of coronary artery spasm in patients with VSA.

Intractable Coronary Spastic Angina Improvement after Continuous Combined Estrogen-progestin Hormonal Contraception Use in a Premenopausal Woman

A 44-year-old woman, who had been previously diagnosed with coronary spastic angina and treated with standard medical therapy including calcium channel blockers, was admitted to our hospital due to chest pain at rest. Her chest pain attacks were concentrated just before and during menstruation. Despite the administration of an intravenous infusion of nitroglycerin and nicorandil, strong heart attacks with ST elevation occurred frequently after this admission. However, following continuous combined estrogen-progestin hormonal contraception use (estradiol plus dienogest), her attacks disappeared completely. Reduced estrogen levels before and during menstruation were speculated to be associated with her angina attacks.

Coronary Spastic Angina Induced after Oral Desmopressin (DDAVP) Administration

A 60-year-old man was prescribed oral desmopressin (1-deamino-8-D-arginine vasopressin acetate trihydrate; DDAVP) for nocturnal polyuria. One week after starting to take desmopressin, he frequently felt chest pain while resting. Coronary angiography revealed no organic stenosis; however, an acetylcholine provocation test showed severe coronary spasm with ST elevation. He was diagnosed with coronary spastic angina, and we stopped the oral desmopressin and added diltiazem. While DDAVP should dilate the coronary vessels in healthy subjects, it may provoke coronary vasospasm in patients with endothelial dysfunction. We should be careful to avoid triggering coronary spasm when administering DDAVP to patients that may have potential endothelial dysfunction.

Association of depression with coronary artery disease and QTc interval prolongation in women with chest pain: data from the KoRean wOmen'S chest pain rEgistry (KoROSE) study

The presence of depression is reportedly related with cardiovascular diseases, including coronary artery disease (CAD), but little is known concerning the association between depressive symptoms reflecting the cultural constructions of female patients with chest pain as well as coronary artery stenosis, coronary vasospasm, and the corrected QT (QTc) interval. In a multicenter prospective cross-sectional survey of 163 Korean women with chest pain, the presence of depression was evaluated using the Beck Depression Inventory (BDI) and Lee and Rhee Depression (LRD) scales. The differences in the QTc interval and the presence of CAD (defined as ≥ 50% coronary artery stenosis on coronary angiography) and coronary vasospasm were compared between depressed and non-depressed women. Significant CAD was present in 83 of 163 female patients (mean age, 61 years), and coronary vasospasm was present in 11 of 80 patients. The mean BDI and LRD scores were significantly higher in patients with significant CAD (BDI: 13.4 ± 9.6 vs. 6.9 ± 5.6, p < 0.001; LRD: 46.9 ± 21.4 vs. 39.8 ± 15.2, p = 0.027) and coronary vasospasm (BDI: 12.3 ± 6.4 vs. 4.6 ± 2.8; and LRD: 49.8 ± 12.3 vs. 30.5 ± 13.9; both p < 0.05). On multivariate analysis, BDI scores were important risk factors for the presence of CAD (odds ratio [OR] = 1.138; 95% confidence interval [CI] = 1.071-1.210; p=0.021) and coronary vasospasm (OR = 2.534; 95% CI = 1.161-2.028; p = 0.003), with similar findings obtained for LRD scores (CAD: OR = 1.034; 95% CI = 1.013-1.056; p = 0.001; coronary vasospasm: OR = 1.125; 95% CI = 1.050-1.206; p = 0.001). The mean QTc interval was also significantly higher in the depressed group than in the non-depressed group (440.1 ± 32.0 ms vs. 408.2 ± 26.4ms; p < 0.001). The QTc interval displayed significant positive with the BDI (r = 0.595; p < 0.001) and LRD scores (r = 0.467; p< 0.001). This study demonstrated that depression is associated with a prolonged QTc interval, CAD, and coronary vasospasm in female patients with chest pain, suggesting a possible mechanism by which depressive mood may be linked with coronary endothelial dysfunction and atherosclerosis.

Circadian influences on myocardial infarction

Components of circadian rhythm maintenance, or "clock genes," are endogenous entrainable oscillations of about 24 h that regulate biological processes and are found in the suprachaismatic nucleus (SCN) and many peripheral tissues, including the heart. They are influenced by external cues, or Zeitgebers, such as light and heat, and can influence such diverse phenomena as cytokine expression immune cells, metabolic activity of cardiac myocytes, and vasodilator regulation by vascular endothelial cells. While it is known that the central master clock in the SCN synchronizes peripheral physiologic rhythms, the mechanisms by which the information is transmitted are complex and may include hormonal, metabolic, and neuronal inputs. Whether circadian patterns are causally related to the observed periodicity of events, or whether they are simply epi-phenomena is not well established, but a few studies suggest that the circadian effects likely are real in their impact on myocardial infarct incidence. Cycle disturbances may be harbingers of predisposition and subsequent response to acute and chronic cardiac injury, and identifying the complex interactions of circadian rhythms and myocardial infarction may provide insights into possible preventative and therapeutic strategies for susceptible populations.

Significant Response to Lower Acetylcholine Dose Is Associated with Worse Clinical and Angiographic Characteristics in Patients with Vasospastic Angina

Background and Objectives

Subjects and Methods

Results

Conclusion

[Coronary artery spasm during dobutamine stress echocardiography: prevalence, clinical and echocardiographic characteristics and prognosis]

OBJECTIVES

To assess the prevalence of coronary artery spasm during dobutamine stress chocardiography (DSE), to describe clinical and echocardiographic characteristics and prognosis.

PATIENTS AND METHODS

We evaluated all the patients with known or suspected coronary artery disease (CAD) referred to our echocardiography laboratory for dobutamine stress test between January 2004 and June 2012, (10013 exams). Those with abnormal DSE underwent coronary angiograms with a systematic methylergometrine intracoronary injection in case of absence of significant coronary stenosis or spontaneous occlusive coronary spasm. Patients who had spontaneous occlusive coronary spasm or positive methylergometrine test but no significant stenoses were included.

RESULTS

One thousand and four patients had abnormal DSE, 78 (7.7%) fulfilled the inclusion criteria. There were 57 males and 21 females, mean age was 57.9 years, 37 patients had a known history of CAD. Twenty-four patients had a spasm on the left anterior artery (31%), 37 on the right coronary artery (47%) and 17 on the circumflex (22%). There was a good correlation between spastic arteries and dobutamine induced wall motion abnormalities territories. No complications occurred during the exams or during the provocation test. After 46 months mean follow up; one case of myocardial infarction with normal coronary arteries was noted and six patients experienced recurrent angina responding to treatment intensification.

CONCLUSION

Coronary artery spasm during DSE but is a rare and under-diagnosed finding; it has, though, to be recognized as it may partly explain some erroneously labelled "false positive" exams. Methylergometrine provocation test should be performed in such a situation to establish the diagnosis. Prognosis appears favourable.

Cardiac syndrome X and microvascular coronary dysfunction

Women with cardiac chest pain indicated by signs and symptoms of myocardial ischemia in the absence of obstructive CAD are often labelled as cardiac syndrome X (CSX). A subset of patients with CSX may have symptoms of ischemia due to microvascular dysfunction. Angina due to microvascular coronary dysfunction (MCD) is an etiologic mechanism in women with vascular dysfunction. New data provide improve understanding of coronary vascular dysfunction and resultant myocardial ischemia that characterize MCD among patients with cardiac syndrome X. MCD has an adverse prognosis and health care cost expenditure comparable to obstructive CAD. The high prevalence of this condition, particularly in women, adverse prognosis and substantial health care costs, coupled with a lack of evidence regarding treatment strategies, places MCD as a research priority area.

Impairment of the extrusion transporter for asymmetric dimethyl-L-arginine: a novel mechanism underlying vasospastic angina

A 37-year old male patient presented with frequent angina attacks (up to 40/day) largely resistant to classical vasodilator therapy. The patient showed severe coronary and peripheral endothelial dysfunction, increased platelet aggregation and increased platelet-derived superoxide production. The endothelial nitric oxide synthase (eNOS)-inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) reduced superoxide formation in platelets identifying "uncoupled" eNOS as a superoxide source. Oral L-arginine normalized coronary and peripheral endothelial dysfunction and reduced platelet aggregation and eNOS-derived superoxide production. Plasma concentrations of the endogenous NOS inhibitor asymmetric dimethyl-L-arginine (ADMA), representing an independent risk factor for cardiovascular disease, were normal in the patient. However, immediately after oral administration of cationic amino acid (CAA), plasma ADMA levels rose markedly, demonstrating increased ADMA efflux from intracellular stores. ADMA efflux from mononuclear cells of the patient was accelerated by CAA, but not neutral amino acids (NAA) demonstrating impairment of y(+)LAT (whose expression was found reduced in these cells). These data suggest that impairment of y(+)LAT may cause intracellular (endothelial) ADMA accumulation leading to systemic endothelial dysfunction. This may represent a novel mechanism underlying vasospastic angina and vascular dysfunction in general. Moreover, these new findings contribute to the understanding of the l-arginine paradox, the improvement of eNOS activity by oral L-arginine despite sufficient cellular l-arginine levels to ensure proper function of this enzyme.

Conformational change in coronary artery structure assessed by optical coherence tomography in patients with vasospastic angina

OBJECTIVES

The aim of this study was to investigate the conformational change of arterial structure in the vasospastic lesion with optical coherence tomography.

BACKGROUND

Coronary artery spasm plays an important role in the pathogenesis of ischemic heart diseases. The conformational change of each arterial layer during vasospasm has not been studied in detail.

METHODS

We assessed 19 coronary arteries (10 spasm and 9 nonspasm lesions) with optical coherence tomography during the provocation test for coronary spasm. An intimal bump was defined as 1 or more intimal projections into the lumen that disappeared after the administration of nitroglycerine (NTG). Intimal gathering was defined as a folding/gathering of the intima, resulting in multiple kinks in the luminal contour that resolved after the administration of NTG.

RESULTS

The spasm lesion more frequently showed an intimal bump at baseline and intimal gathering during spasm compared with the nonspasm lesion (spasm 80% vs. nonspasm 0%, p < 0.01, spasm 100% vs. nonspasm 0%, p < 0.01, respectively). The spasm lesion demonstrated a thicker maximum media thickness (spasm 0.24 ± 0.04 mm vs. nonspasm 0.12 ± 0.03 mm, p < 0.01) at baseline, whereas no differences were observed after the administration of NTG (spasm 0.13 ± 0.03 mm vs. nonspasm 0.13 ± 0.02 mm, p = 0.65).

CONCLUSIONS

Our results suggest that medial contraction occurs even in an asymptomatic state and facilitates the formation of an intimal bump in patients with vasospastic angina. Luminal narrowing during spasm is associated with intimal gathering without alteration of intimal area.

Myocardial infarction and normal coronary arteries: the experience of the cardiology department of Sfax, Tunisia

OBJECTIVE

The purpose of the present study is to describe our experience with patients who have a transmural myocardial infarction (MI) in the presence of a normal coronary artery. The clinical profile, demographic characteristics and outcomes of these patients are discussed.

METHODS

Between January 2006 and August 2011, 21 patients who presented with a Q-wave myocardial infarction were found to have normal coronary arteries. The prevalence rate of this entity was 1.5% (21 out of 1,400 Q wave MI patients). These patients were characterized by their young age (the mean age=44.95±14.86), male dominance (90.47%), and a high prevalence of smoking (85.71%). In this study, 4 patients have an evident spontaneous spasm shown on coronary angiography which disappeared after intracoronary injection of nitrates. Coagulation Disorders, such as activated protein C resistance (APC) resistance, protein C deficiency and antiphospholipid antibody syndrome were found in 4 of 12 patients who underwent systematic examination. One patient had a history of lung cancer which may be associated with a hypercoagulable state and may explain the occurrence of myocardial infarction with a normal coronary artery. The mean left ventricle ejection was 56. 5±12. The mean follow-up was 24±10 months. Six patients developed residual chest pain which was generally easily controlled by anti-spastic therapy and no patient had a major cardiovascular event.

CONCLUSION

Patients with Q-wave MI and with normal coronary arteries seem to have a good short and long-term prognosis especially when they are treated with an exclusive medical strategy.

Change of coronary flow velocity during the cold pressor test is related to endothelial markers in subjects with chest pain and a normal coronary angiogram

BACKGROUND

Several studies demonstrated that endothelial or atherosclerotic biomarkers, including plasma free insulin-like growth factor-I(IGF-I), soluble CD40 ligand (sCD40L), adiponectin, and leptin have an influence on coronary endothelial function.

HYPOTHESIS

The aim of the present study was to investigate whether change of coronary flow velocity of the distal left anterior descending artery (LAD) during the cold pressor test (CPT) with transthoracic Doppler echocardiography (TTE) was associated with these biomarkers in subjects with chest pain and a normal coronary angiogram.

METHODS

In 190 subjects (mean age, 54±11 years; male:female, 113:77) with chest pain and a normal coronary angiogram, peak diastolic velocity (PDV) of the distal LAD during the CPT with TTE was assessed. Acetylcholine provocation test was performed in 58 subjects (mean age, 51±10 years) who were clinically suspected of vasospasm. CPT%PDV was defined as the percent change in PDV during the CPT. Associations between CPT%PDV and clinical parameters were analyzed.

RESULTS

According to multiple regression analysis, CPT%PDV was associated with plasma free IGF-I in the entire study population (β=0.295, P<0.001 in all subjects; β=0.341, P=0.001 in males; β=0.243, P=0.037 in females; β=0.303, P=0.002 in nonsmokers; and β=0.256, P=0.047 in smokers), and sCD40L in males (β=-0.269, P=0.008)and smokers (β=-0.261, P=0.046). Subjects with vasospasm to intracoronary acetylcholine had lower plasma free IGF-I(6.9±3.3 vs 8.9±3.4, P=0.026) and CPT%PDV (8.8±24.9 vs 52.7±26.0, P<0.001) than the others. Plasma adiponectin and leptin were not associated with CPT%PDV.

CONCLUSIONS

Change of coronary flow velocity assessed using the CPT with TTE may be related to endothelial markers, especially plasma free IGF-I.

Myocardial ischaemia in patients with coronary endothelial dysfunction: insights from body surface ECG mapping and implications for invasive evaluation of chronic chest pain

AIMS

Coronary endothelial dysfunction (ED), by predisposing to abnormal vasomotion, may cause chest pain in individuals with non-obstructed coronary arteries. The aim of this study was to correlate the magnitude of coronary ED with the presence and extent of inducible myocardial ischaemia using body surface electrocardiogram (ECG) mapping in symptomatic patients.

METHODS AND RESULTS

In 30 patients with chest pain and angiographically normal coronary arteries or mild atherosclerosis, we studied endothelium-dependent responses with acetylcholine (ACH) and endothelium-independent function with nitroglycerin and adenosine in the left anterior descending artery. Eighty-lead body surface ECG maps were collected at baseline and after each dose of ACH. There was a significant correlation between the maximal change in epicardial diameter with ACH and the magnitude of ST-segment shift [r = -0.44 (95% CI: -0.097 to -0.69), P = 0.015]. Patients with ≥ 0.05 mV ST-segment shift/lead had greater epicardial vasoconstriction (31.6 vs. 15.6%, P = 0.019), and lower coronary flow reserve (2.9 vs. 3.6, P = 0.047) compared with those with ST-segment shift <0.05 mV. Four patients had inducible ischaemia with ACH in the absence of abnormal epicardial or global microvascular vasomotion (>20% decrease in diameter or <50% increase in blood flow).

CONCLUSIONS

This study demonstrates that abnormal vasomotion due to coronary ED is associated with myocardial ischaemia in patients with chest pain. The magnitude of ischaemia correlates with the extent of ED. A small subset of patients develop myocardial ischaemia during ACH infusion without significant abnormalities in epicardial or global microvascular endothelium-dependent blood flow responses.

Transient ST-segment elevation due to iatrogenic hyperthyroidism in a patient with normal coronary arteries

A 53-year-old man presented with angina pectoris and ST-segment elevation in V(1)-V(4) leads. Electrocardiogram changes and chest pain were completely resolved with nitroglycerine infusion. Coronary angiogram revealed normal epicardial vessels. These findings suggest that the acute myocardial ischemia was secondary to coronary vasospasm. From his medical history we learned that he was taking L-thyroxine and the dose had been increased two months previously. He was found to be in thyrotoxic state at admission. L-thyroxine treatment was withheld and diltiazem was given. He had no further symptoms. In conclusion we think that acute myocardial ischemia was likely secondary to L-thyroxine-induced coronary spasm.

Nongenomic inhibition of coronary constriction by 17ß-estradiol, 2-hydroxyestradiol, and 2-methoxyestradiol

The cardioprotective effects of 17beta-estradiol (E2) in women are hypothesized to be partially mediated by the E2 metabolites 2-hydroxyestradiol (2-HOE) and 2-methoxyestradiol (2-MeOH). Therefore, the purpose of our study was to determine the acute effects of E2, 2-HOE, and 2-MeOH on inhibition of coronary arterial constriction. Right coronary arteries obtained from breeding sows were cut into 4 mm rings and suspended in organ baths. Incubation of the rings with E2, 2-HOE, and 2-MeOH (10 micromol/L) for 60 min attenuated a subsequent KCl-induced contraction by approximately 50%. The protein synthesis inhibitor cycloheximide and the estrogen receptor antagonists ICI 182780 and tamoxifen did not affect the attenuation. Moreover, E2, 2-HOE, and 2-MeOH antagonized the contraction induced by the vasospasm agonist endothelin-1 (0.1 micromol/L) by approximately 36%. When the L-type Ca2+ channel blocker nifedipine was added at the conclusion of the experiment, no additional contractile attenuation was present. Our results suggest that E2, 2-HOE, and 2-MeOH demonstrate a similar nongenomic inhibition of agonist-induced extracellular Ca2+-dependent contractions.

Cardiac arrest in the left lateral decubitus position and extracorporeal cardiopulmonary resuscitation during neurosurgery: a case report

Cardiopulmonary resuscitation (CPR) in the lateral position during noncardiac surgery has been described in only a few reports in the past. Here, we report a case of cardiac arrest in a 61-year-old man undergoing microvascular decompression surgery for trigeminal neuralgia in the left lateral decubitus position. During the initial 5 min of CPR, chest compression was performed in this position by two rescuers; one from the chest and the other from the back, pushing simultaneously. Because ventricular arrhythmia was refractory to conventional CPR even after placing the patient back to the supine position, extracorporeal life support was introduced in the operating room by using the femoro-femoral approach (right atrio-femoral veno-arterial bypass). This alternative CPR markedly decreased the frequency of ventricular arrhythmia. Subsequent coronary angiogram detected 99% stenosis of the right coronary artery. Ventricular arrhythmia ceased after coronary revascularization, and the patient was successfully weaned from the extracorporeal bypass circuit. The patient was discharged alive with minimal neurological impairment. We suggest that chest compression in the lateral position by two rescuers is an efficient resuscitation maneuver, and if an electrical storm is refractory to conventional CPR, extracorporeal life support should be considered in the operating-room setting.

Nonacute coronary syndrome anginal chest pain

Anginal chest pain is one of the most common complaints in the outpatient setting. While much of the focus has been on identifying obstructive atherosclerotic coronary artery disease (CAD) as the cause of anginal chest pain, it is clear that microvascular coronary dysfunction (MCD) can also cause anginal chest pain as a manifestation of ischemic heart disease, and carries an increased cardiovascular risk. Epicardial coronary vasospasm, aortic stenosis, left ventricular hypertrophy, congenital coronary anomalies, mitral valve prolapse, and abnormal cardiac nociception can also present as angina of cardiac origin. For nonacute coronary syndrome (ACS) stable chest pain, exercise treadmill testing (ETT) remains the primary tool for diagnosis of ischemia and cardiac risk stratification; however, in certain subsets of patients, such as women, ETT has a lower sensitivity and specificity for identifying obstructive CAD. When combined with an imaging modality, such as nuclear perfusion or echocardiography testing, the sensitivity and specificity of stress testing for detection of obstructive CAD improves significantly. Advancements in stress cardiac magnetic resonance imaging enables detection of perfusion abnormalities in a specific coronary artery territory, as well as subendocardial ischemia associated with MCD. Coronary computed tomography angiography enables visual assessment of obstructive CAD, albeit with a higher radiation dose. Invasive coronary angiography remains the gold standard for diagnosis and treatment of obstructive lesions that cause medically refractory stable angina. Furthermore, in patients with normal coronary angiograms, the addition of coronary reactivity testing can help diagnose endothelial-dependent and -independent microvascular dysfunction. Lifestyle modification and pharmacologic intervention remains the cornerstone of therapy to reduce morbidity and mortality in patients with stable angina. This review focuses on the pathophysiology, diagnosis, and treatment of stable, non-ACS anginal chest pain.

Cardiac complication after experimental human malaria infection: a case report

A 20 year-old healthy female volunteer participated in a clinical Phase I and IIa safety and efficacy trial with candidate malaria vaccine PfLSA-3-rec adjuvanted with aluminium hydroxide. Eleven weeks after the third and last immunization she was experimentally infected by bites of Plasmodium falciparum-infected mosquitoes. When the thick blood smear became positive, at day 11, she was treated with artemether/lumefantrine according to protocol. On day 16 post-infection i.e. two days after completion of treatment, she woke up with retrosternal chest pain. She was diagnosed as acute coronary syndrome and treated accordingly. She recovered quickly and her follow-up was uneventful. Whether the event was related to the study procedures such as the preceding vaccinations, malaria infection or antimalarial drugs remains elusive. However, the relation in time with the experimental malaria infection and apparent absence of an underlying condition makes the infection the most probable trigger. This is in striking contrast, however, with the millions of malaria cases each year and the fact that such complication has never been reported in the literature. The rare occurrence of cardiac events with any of the preceding study procedures may even support a coincidental finding.

Apart from acute coronary syndrome, myocarditis can be considered as a final diagnosis, but the true nature and patho-physiological explanation of the event remain unclear.

Hemodynamic alterations in the coronary circulation of cardiomyopathic hamsters: age and Ang II-dependent mechanisms

BACKGROUND

Coronary vasospasms have been reported in the early stages of cardiomyopathy in the Syrian cardiomyopathic hamster (CM; BIO-TO2 strain). It has been proposed these alterations could lead to ischemic heart disease and heart failure. However, the cause of these coronary abnormalities has not been established. In this study, we evaluated coronary hemodynamic to assess the role of Ang-II, reactive oxygen species, and nitric oxide (NO) in the development of these alterations in CM of 1, 2, and 6 months of age.

METHODS AND RESULTS

Excised hearts from control (CT) and CM were retroperfused with Krebs-Ringer bicarbonate solution (KRB), and coronary resistance (CR) was determined. The experimental protocol involved sequential infusions of the thromboxane analog U46619 (THX, 0.1micromol/L), bradykinin (BKN, 10micromol/L), and sodium nitroprusside (SNP, 10micromol/L). Similar experiments were conducted after treatment of hearts with N(omega)-nitro-L-arginine methyl ester (L-NAME, 10micromol/L). Basal CR increased with age, but no significant differences were observed between CT and CM. Reactivity to THX was increased (69%, P < .05) in 2-month-old CM when compared with CT. This effect was observed concomitantly with a significant reduction (53%, P < .05) in BKN-induced relaxation. The reduction in BKN-dependent relaxation was prevented by treatment for 1 month with the antioxidant N-acetylcysteine (1 g.kg.day), or losartan, an Ang II type 1 receptor blocker (10 mg.kg.day). Losartan also prevented the THX-induced increased reactivity in 2-month-old CM. The BKN-induced relaxation occurred through an L-NAME-sensitive pathway that was impaired with age. SNP dilation was preserved in all animal groups.

CONCLUSIONS

Our results strongly implicate vascular renin-angiotensin-system (RAS) and oxidative stress in endothelial dysfunction and increased reactivity in the early stages of cardiomyopathy in CM. These findings could be relevant to understand the etiology of cardiovascular disorders, in particular, in patients with sarcoglycanopathies.

Mutation of ARHGAP9 in patients with coronary spastic angina

Coronary artery spasm has an important function in the etiology of variant angina and other acute coronary syndromes. Abnormal activation of Rho-family GTPases has been observed in cardiovascular disorders, but the function of genetic variability in Rho-family GTPases remains to be evaluated in cardiovascular disorders. We examined the genetic variability of Rho-family GTPases and their regulators in coronary artery spasm. We performed a comprehensive candidate gene analysis of 67 single nucleotide polymorphisms with amino-acid substitution in Rho-family GTPases and their regulators in 103 unrelated Japanese patients with acetylcholine-induced coronary artery spasm and 102 control Japanese subjects without acetylcholine-induced coronary artery spasm. We noted an association of the single nucleotide polymorphism of ARHGAP9 (rs11544238, Ala370Ser) with coronary artery spasm (odds ratio =2.67). We found that ARHGAP9 inactivated Rac as RacGAP and that the mRNA level of ARHGAP9 was strongly detected in hematopoietic cells. ARHGAP9 negatively regulated cell migration. The Ala370Ser polymorphism counteracted ARHGAP9-reduced cell migration, spreading and adhesion. The Ala370Ser polymorphism in the ARHGAP9 gene is associated with coronary artery spasm. These data suggest that the polymorphism of ARHGAP9 has a critical function in the infiltration of hematopoietic cells into the endothelium and inflammation leading to endothelial dysfunction.

Coronary artery spasm and dobutamine stress echocardiography

AIMS

The aim of this article was to assess whether abnormal dobutamine stress echocardiography (DSE) can be due to a dobutamine-induced coronary spasm in patients with angiographically documented vasospastic coronary arteries.

METHODS AND RESULTS

Between January 2004 and April 2008, we prospectively evaluated all patients with known or suspected coronary artery disease (CAD) referred to the echocardiography laboratory for dobutamine stress tests (6061 examinations). Those with abnormal DSE underwent coronary angiogram with a systematic methylergometrine intracoronary injection in the case of absence of significant coronary stenosis or spontaneous occlusive coronary spasm. Patients who had spontaneous occlusive coronary spasm or positive methylergometrine test, but no significant stenoses, were ultimately included in this study. About 581 patients had abnormal DSE, among them only 20 (3.4%) fulfilled the inclusion criteria. There were 15 males and 5 females, and mean age was 64.35 years (range 52-85); 8 patients had a known history of CAD and all of them had at least two established cardiovascular risk factors. The culprit vessel was the left anterior descending artery in 10 cases (50%), right coronary artery in 8 cases (40%), and left circumflex in 2 cases (10%). There was a systematic correspondence between the culprit arteries and dobutamine-induced wall motion abnormality territories. No complications occurred during examination or during the provocation test. All the patients were discharged with a calcium channel blocker and were doing well after 13 months of mean follow-up.

CONCLUSION

Coronary artery spasm can be induced at DSE, but is a rare finding; it could, though, be clinically relevant as it may partly explain some erroneously labelled 'false-positive' examinations. Methylergometrine provocation test is a safe and advisable approach in such situations.

[Non ST elevation acute coronary syndromes and normal coronary angiography: is it truly good news?]

Among 10% of all patients presenting with non ST elevation acute coronary syndromes (ACS), coronary angiography do not show non lesions at all (50%) or mild atheromatous stenosis (50%). ACS without angiographic stenosis are more prevalent in female sex and young patients but can be seen in older ones and in men. Pathogenic mechanisms include acute evolution of vulnerable non-significant plaques and endothelial dysfunction. In hospital and mean term prognosis is not as benign as expected. Six months deaths and myocardial infarction incidence is around 6%. Numerous rehospitalizations due to ischemic recurrences are also very often seen. Therefore, such surprising coronary angiograms do not preclude a fair follow-up. These patients need a careful therapeutic strategy.

Sustained contraction and endothelial dysfunction induced by reactive oxygen species in porcine coronary artery

A combination of purine and xanthine oxidase (XOD) dose-dependently elicited sustained contraction of porcine coronary arterial rings and resulted in increased concentrations of superoxide anions and hydrogen peroxide. These contractile responses appeared, with a delay, after the application of purine and XOD, used as a reactive oxygen species (ROS)-generating system. Coronary arteries precontracted with prostaglandin F(2alpha) failed to relax in response to substance P after exposing the arterial preparation to this ROS-generating system. The contractile response of the coronary artery to the ROS-generating system was almost completely inhibited by catalase (130 U/ml), and was partially inhibited by superoxide dismutase (60 U/ml), or mannitol (30 mM). A voltage-dependent L-type Ca(2+) channel antagonist, nicardipine, had no effect on contraction. Dysfunction of endothelial cells was completely prevented by catalase, but not by superoxide dismutase or mannitol. These results suggest that superoxide anions, hydrogen peroxide and hydroxyl radicals might be involved in eliciting sustained, delayed-onset coronary artery contraction, which is not related to L-type Ca(2+) channels. They also suggest that hydrogen peroxide might play a major role in endothelial dysfunction of the porcine coronary artery.

Effect of OS-0544, a selective estrogen receptor modulator, on endothelial function and increased sympathetic activity in ovariectomized rats

Estrogens are known to contribute to endothelial function and sympathetic activity, both of which are strongly associated with the pathogenesis of ischemic heart disease. In addition, estrogens improve impaired lipid profile, a risk factor of endothelial dysfunction. In this study, we investigated the effects of OS-0544, a structurally new selective estrogen receptor modulator (SERM), on endothelial function, sympathetic activity, and plasma cholesterol level in ovariectomized (OVX) rats. Female Sprague-Dawley rats were ovariectomized and orally treated with OS-0544 (or OS-0689, the (R)-enantiomer of OS-0544), or 17beta-estradiol (E2) for 4 weeks, starting the next days after ovariectomy or for 1 week, starting 6 weeks after ovariectomy. Ovariectomy significantly increased vasopressin-induced mean blood pressure (AVP-MBP) (57+/-3.3 mm Hg vs. 46+/-3.5 mm Hg, P<0.05) and decreased acetylcholine (Ach)-induced maximum vasorelaxation response (69+/-5.6% vs. 81+/-4.0%, P<0.05). OS-0544 significantly inhibited AVP-MBP elevation (46+/-3.5 mm Hg vs. 57+/-3.3 mm Hg, P<0.05) and decreased Ach-induced maximum vasorelaxation response (90+/-3.3% vs. 69+/-5.6%, P<0.05) in OVX rats. In addition, OS-0689 as well as E2 significantly reduced (up to 67%) the increase in sympathetic activity in OVX rats. Moreover, like E2, OS-0544 significantly decreased plasma cholesterol level in OVX rats. These results demonstrate that OS-0544 has vascular protective effect on vascular function after ovariectomy. It is therefore believed that OS-0544 has vascular protective effect in postmenopausal woman.

17beta-estradiol inhibits calcium-dependent and -independent contractions in isolated human saphenous vein

Studies suggest that estrogen modulate vascular reactivity but at present its exact mechanism of action has yet to be clarified. The aim of this study was to evaluate the effect of 17beta-estradiol (E2) on calcium-dependent and -independent contractions induced in the human saphenous veins (HSVs). HSVs were obtained from patients undergoing coronary artery bypass graft surgery. The ability of E2 to modulate Ca(2+) entry was assessed by obtaining concentration-response curve to CaCl(2) in the absence or presence of E2. In other experiments intracellular Ca(2+) was depleted by repeated application of phenylephrine in the presence of cyclopiazonic acid (CPA). Then, at the plateau of PGF(2alpha) contraction, E2 or nifedipine (NIF) was added. Involvement of protein kinase C (PKC) in relaxant effect of E2 was evaluated by application of phorbol-12,13-dibutyrate (PDBu) in normal or Ca(2+)-free Krebs' solution. When the contraction was obtained, E2 or NIF was added. In Ca(2+)-free hyperpolarizing solution, pretreatment with E2, concentration dependently reduced contractions induced by cumulative addition of calcium chloride. Furthermore, E2 elicited relaxant effects on the PGF(2alpha)-induced contractions in Ca(2+)-free solution in the presence or absence of CPA. Both E2 and NIF produced significant relaxation in HSV rings contracted by direct activation of PKC in Krebs' solution. However, in Ca(2+)-free solution, NIF failed to induce relaxant effect but E2 kept its effect on the PDBu-induced contraction. These results suggest that the relaxant effect of E2 on HSV is elicited by calcium-dependent and -independent pathways. The calcium-independent pathway may involve PKC inhibition.

Multiple episodes of ventricular tachycardia induced by silent coronary vasospasm

We present a 46-year-old patient who suffered from cardiac arrest and subsequently underwent placement of an implantable cardioverter defibrillator (ICD). The patient underwent a cardiac catheterization which revealed no significant coronary artery disease. About 1 year later he experienced appropriated and frequent ICD discharges due to monomorphic ventricular tachycardia (VT) with left bundle branch block morphology. His prodromal symptoms were mild dizziness and lightheadedness with no chest pain. Amiodarone, mexiletine, sotalol and dofetilide as well as ablation of two inducible ventricular tachycardias in the electrophysiology studies were unsuccessful in controlling the arrhythmias and ICD discharges. During the last episode, he experienced a mild burning sensation in his chest and was given nitroglycerin 0.4 mg sublingually, which relived his symptoms and aborted the VT. This led to a second cardiac catheterization to investigate whether the VT was being induced by myocardial ischemia. This second coronary angiogram spontaneously revealed significant coronary vasospasm and simultaneously, the patient's cardiac rhythm showed short runs of VT with left bundle branch block morphology. Intracoronary nitroglycerine relieved the coronary vasospasm and terminated the arrhythmia. The patient was treated with isosorbide mononitrate and diltiazem. He remained symptom free with no ICD discharges and no VT in ICD interrogations for more than 2 years. Coronary vasospasm may be silent and with no chest pain which creates a difficult clinical situation particularly if it is associated with ventricular tachycardia and sudden cardiac death. The mechanisms of VT in the setting of coronary vasospasm are not known and increased automaticity, focal discharges, functional unidirectional block with reentry, or a combination of these mechanisms may contribute to inducing the VT during the transient ischemia or rarely in the reperfusion phase. It is important to perform provocative tests to diagnose silent coronary vasospasm in unexplained sudden cardiac arrests.

Clinical and angiographic characteristics of acute myocardial infarction caused by vasospastic angina without organic coronary heart disease

BACKGROUND

Vasospastic angina (VA) can occasionally cause acute myocardial infarction (AMI).

METHODS AND RESULTS

From January 2003 to June 2005, coronary spastic angina was diagnosed in 292 patients by performing spasm provocation tests. Among the 292 patients, 21 (7.2% of all the VA patients) had an AMI. There were 20 patients who initially visited the emergency room for AMI without suffering prior VA. One patient with a history of VA had an AMI when he discontinued his medication. Among the 21 VA patients with AMI, 14 had experienced severe emotional stress before they visited the emergency room. The spasm provocation test showed that the VA patients with AMI had more multivessel and diffuse spasm than the VA patients without AMI (p<0.001).

CONCLUSION

Clinically, the VA patients with AMI usually had their first symptom of VA as the severe chest pain of AMI. Two-thirds of the VA patients with AMI had experienced emotional stress before their AMI. Angiographically, the spasm provocation test for VA patients with AMI showed more multivessel and diffuse spasm than in VA patients without AMI.

Serum deoxyribonuclease I activity can be used as a novel marker of transient myocardial ischaemia: results in vasospastic angina pectoris induced by provocation test

AIMS

Serum deoxyribonuclease I (DNase I) activity has recently been highlighted as a potential diagnostic marker for detection of acute myocardial infarction. To evaluate whether serum DNase I activity is useful for detection of myocardial ischaemia, we investigated alteration of its levels after onset of vasospastic angina pectoris (VSAP), resulting in transient myocardial ischaemia, induced by the intracoronary ergonovine provocation test.

METHODS AND RESULTS

Twenty-nine consecutive patients with suspected VSAP were subjected to the test. Patients were categorized as VSAP-positive (n = 13) or -negative (n = 16) based on development of angina. Serum samples were examined for DNase I activity before, immediately after, and 3, 6, and 24 h after the provocation tests. The serum DNase I activity increased significantly from the baseline 3 h after the provocation test in 11 patients of the VSAP-positive group whose levels of troponin T were within the normal range. Median of the percentage differences from the baseline in serum DNase I activity 3 h after the test was 32.1% (25th and 75th percentile: 28.6 and 42.0%, respectively; P = 0.000012). In the VSAP-negative group, levels of DNase I activity remained unchanged at any point of time after the provocation test.

CONCLUSION

Transient myocardial ischaemia resulting from VSAP induces a significant elevation of serum DNase I activity. Therefore, serum DNase I activity may be applicable as a useful marker for detecting transient myocardial ischaemia.

A case of capecitabine-induced coronary microspasm in a patient with rectal cancer

5-Fluorouracil (5-FU) is the most frequently used chemotherapy agent concomitant with radiotherapy in the management of patients with rectal cancer. Capecitabine is an oral fluoropyrimidine that mimics the pharmaconkinetics of infusional 5-FU. This new drug is replacing 5-FU as a part of the combined-modality treatment of a number of gastrointestinal cancers. While cardiac events associated with the use of 5-FU are a well known side effect, capecitabine-induced cardiotoxicity has been only rarely reported. Here, we reviewed the case of a patient with rectal cancer who had a capecitabine-induced coronary vasospasm. The most prominent mutation of the dihydropyrimidine dehydrogenase gene was also analyzed.

Myocardial infarction with normal coronary arteries: a conundrum with multiple aetiologies and variable prognosis: an update

The existence of myocardial infarction despite angiographically normal coronary arteries was recognized more than 30 years ago. Since then, various series of such patients have been described, but the aetiology and pathogenesis of the condition are still a source of debate. Evidence exists for a role of coronary vasospasm, thrombosis, embolization and inflammation, per se or combined, in determining the occurrence of myocardial infarction in the presence of angiographically normal coronary arteries. Endothelial dysfunction, possibly superimposed to nonangiographically evident atherosclerosis, may be an underlying common feature predisposing to the acute event. Additionally, myocarditis may explain some of these occurrences. Myocardial infarction with normal coronary arteries is therefore likely the result of multiple pathogenetic mechanisms. Although most reports emphasize the good prognosis of this condition, in general much better than myocardial infarction with coronary artery disease, prognosis is likely variable according to the underlying mechanism. This review summarizes current knowledge on this condition and examines areas of recent progress.

The mystery of coronary artery spasm

Coronary artery spasm is an important cause of chest pain and myocardial ischaemia. It can be defined as an exaggerated contractile response of epicardial coronary artery smooth muscle to various stimuli but the underlying mechanism is not well understood. Recent studies have shown that the loss of endothelial vasodilatory function in conjunction with an increase in vascular smooth muscle constrictor sensitivity to calcium are the likely predisposing conditions for coronary spasm. This review highlights current understanding of the pathophysiology, predisposing factors, diagnostic and therapeutic approaches for coronary spasm.

An increased monocyte count predicts coronary artery spasm in patients with resting chest pain and insignificant coronary artery stenosis

BACKGROUND

Coronary atherosclerosis with inflammation gives rise to coronary vasospasm in the patients with coronary vasospastic angina. We have postulated that the peripheral leukocyte count and the differential count are associated with vasospastic angina.

METHODS

144 patients who underwent intracoronary ergonovine provocation testing between January 2002 and December 2004 were divided into two groups: Group I (72 patients with provoked spasm, mean age: 54.8 +/- 10.7 years, males: 75%) and Group II (72 without spasm, mean age: 55.3 +/- 10.2 years, males: 35%). Blood sampling was done to measure the lipid profiles and inflammatory markers, including the high sensitive C-reactive protein (hsCRP) levels and the monocyte counts. We compared the angiographic findings and laboratory data between the two groups.

RESULTS

There were no significant differences in the levels of serum lipid and hsCRP between the two groups. The white blood cell count and the monocyte count were higher in Group I than with Group II (7496.4 +/- 2622.28 vs. 6703.2 +/- 1768.37/mm3, respectively, p = 0.035; 627.5 +/- 270.70 vs. 426.9 +/- 205.76/mm3, respectively, p < 0.001). Gensini's score was higher in Group I than in Group II (2.2 +/- 2.88 vs. 0.5 +/- 1.03, respectively, p < 0.001). Multivariate analysis showed that the monocyte count and Gensini's score were independent factors affecting coronary spasm (p = 0.047 and p = 0.018, respectively). According to a receiver operating characteristics curve analysis, the area under the curve of the monocyte count was 0.738, that of the neutrophil count was 0.577 and that of the WBC count was 0.572. The cut-off value of the monocyte count was 530/mm3; the sensitivity and specificity of this cut-off value were 64% and 76%, respectively.

CONCLUSIONS

The peripheral monocyte count is an independent marker for predicting vasospastic angina in the patients with resting chest pain and insignificant coronary artery stenosis.