Angina pectoris caused by coronary microvascular spasm

Association of statin therapy with clinical outcomes in patients with vasospastic angina: Data from Korean health insurance review and assessment service

There is conflicting evidence for the clinical benefit of statin therapy in patients with vasospastic angina (VSA). We investigated the association of statin therapy with clinical outcomes in relatively large populations with clinically suspected VSA from a nationwide population-based database. Data were collected from the Health Insurance Review and Assessment database records of 4,099 patients that were in an intensive care unit with VSA between January 1, 2008 and May 31, 2015. We divided the patients into a statin group (n = 1,795) and a non-statin group (n = 2,304). The primary outcome was a composite of cardiac arrest and acute myocardial infarction (AMI). The median follow-up duration was 3.8 years (interquartile range: 2.2 to 5.8 years). Cardiac arrest or AMI occurred in 120 patients (5.2%) in the statin group, and 97 patients (5.4%) in the non-statin group (P = 0.976). With inverse probability of treatment weighting, there was no significant difference in the rate of cardiac arrest or AMI between the two groups (adjusted hazard ratio [HR], 0.99; 95% confidence interval [CI], 0.76–1.30; P = 0.937), or even between the non-statin group and high-intensity statin group (adjusted HR, 1.08; 95% CI, 0.69–1.70; P = 0.75). The beneficial association of statin use with the primary outcome was consistently lacking across the various comorbidity types. Statin therapy was not associated with reduced cardiac arrest or AMI in patients with VSA, regardless of statin intensity. Prospective, randomized trials will be needed to confirm our findings.

Systemic microvascular dysfunction in microvascular and vasospastic angina

Aims

Coronary microvascular dysfunction and/or vasospasm are potential causes of ischaemia in patients with no obstructive coronary artery disease (INOCA). We tested the hypothesis that these patients also have functional abnormalities in peripheral small arteries.

Methods and results

Patients were prospectively enrolled and categorised as having microvascular angina (MVA), vasospastic angina (VSA) or normal control based on invasive coronary artery function tests incorporating probes of endothelial and endothelial-independent function (acetylcholine and adenosine). Gluteal biopsies of subcutaneous fat were performed in 81 subjects (62 years, 69% female, 59 MVA, 11 VSA, and 11 controls). Resistance arteries were dissected enabling study using wire myography. Maximum relaxation to ACh (endothelial function) was reduced in MVA vs. controls [median 77.6 vs. 98.7%; 95% confidence interval (CI) of difference 2.3-38%; P = 0.0047]. Endothelium-independent relaxation [sodium nitroprusside (SNP)] was similar between all groups. The maximum contractile response to endothelin-1 (ET-1) was greater in MVA (median 121%) vs. controls (100%; 95% CI of median difference 4.7-45%, P = 0.015). Response to the thromboxane agonist, U46619, was also greater in MVA (143%) vs. controls (109%; 95% CI of difference 13-57%, P = 0.003). Patients with VSA had similar abnormal patterns of peripheral vascular reactivity including reduced maximum relaxation to ACh (median 79.0% vs. 98.7%; P = 0.03) and increased response to constrictor agonists including ET-1 (median 125% vs. 100%; P = 0.02). In all groups, resistance arteries were ≈50-fold more sensitive to the constrictor effects of ET-1 compared with U46619.

Conclusions

Systemic microvascular abnormalities are common in patients with MVA and VSA. These mechanisms may involve ET-1 and were characterized by endothelial dysfunction and enhanced vasoconstriction.

Clinical trial registration

ClinicalTrials.gov registration is NCT03193294.

The effects of remote ischaemic preconditioning on coronary artery function in patients with stable coronary artery disease

Background

Remote ischaemic preconditioning (RIPC) is a cardioprotective intervention invoking intermittent periods of ischaemia in a tissue or organ remote from the heart. The mechanisms of this effect are incompletely understood. We hypothesised that RIPC might enhance coronary vasodilatation by an endothelium-dependent mechanism.

Methods

We performed a prospective, randomised, sham-controlled, blinded clinical trial. Patients with stable coronary artery disease (CAD) undergoing elective invasive management were prospectively enrolled, and randomised to RIPC or sham (1:1) prior to angiography. Endothelial-dependent vasodilator function was assessed in a non-target coronary artery with intracoronary infusion of incremental acetylcholine doses (10^− 6, 10^− 5, 10^− 4 mol/l). Venous blood was sampled pre- and post-RIPC or sham, and analysed for circulating markers of endothelial function. Coronary luminal diameter was assessed by quantitative coronary angiography. The primary outcome was the between-group difference in the mean percentage change in coronary luminal diameter following the maximal acetylcholine dose (Clinicaltrials.gov identifier: NCT02666235).

Results

75 patients were enrolled. Following angiography, 60 patients (mean ± SD age 57.5 ± 8.5 years; 80% male) were eligible and completed the protocol (n = 30 RIPC, n = 30 sham). The mean percentage change in coronary luminal diameter was − 13.3 ± 22.3% and − 2.0 ± 17.2% in the sham and RIPC groups respectively (difference 11.32%, 95%CI: 1.2– 21.4, p = 0.032). This remained significant when age and sex were included as covariates (difference 11.01%, 95%CI: 1.01– 21.0, p = 0.035). There were no between-group differences in endothelial-independent vasodilation, ECG parameters or circulating markers of endothelial function.

Conclusions

RIPC attenuates the extent of vasoconstriction induced by intracoronary acetylcholine infusion. This endothelium-dependent mechanism may contribute to the cardioprotective effects of RIPC.

Clinical care for patients with recurrent myocardial ischemia in Germany-the VOICES trial

Background

Chronic ischemic heart disease is frequent and represents the most common cause of death in western countries. Angina pectoris, the clinical symptom of myocardial ischemia, is associated with increased morbidity and mortality also in patients without obstructive coronary artery disease. The aim of this study was to investigate the current care of patients with recurrent myocardial ischemia after ruling out significant coronary stenosis in the setting of outpatient care.

Methods

Data were obtained by a detailed and structured survey. German cardiologists in outpatient care were interviewed about the management and treatment of outpatients with recurrent angina pectoris after ruling out significant stenoses by coronary angiography. Items were analysed using rating scales [1-10] by means of descriptive methods. Absolute and relative frequency distribution was calculated for the characterisation of qualitative data and multiple-choice questions.

Results

The interviews of 731 cardiologic experts could be included in this analysis. The main results showed that history taking seems to be one major problem in those patients-more than 10% of the expert cardiologists admit that they do not perform a detailed history taking of patients with recurrent angina pectoris. While a classification of the symptoms by means of the CCS classification is rated as important such a classification is not used on a regular basis. Extra-cardiac causes are frequently not excluded before performing coronary angiography (>10% of the cases). A significant fraction (20%) of German cardiologists does not consider the initiation of a specific, antianginal medical treatment as their objective.

Conclusions

The trial revealed deficiencies in the history taking, the proper classification of the symptoms, and the initiation of an adequate drug therapy in patients with recurrent angina pectoris after exclusion of significant coronary stenoses.

Editor's Choice- Pathophysiology, diagnosis and management of MINOCA: an update

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a syndrome with different causes, characterised by clinical evidence of myocardial infarction with normal or near-normal coronary arteries on angiography. Its prevalence ranges between 5% and 25% of all myocardial infarction. The prognosis is extremely variable, depending on the cause of MINOCA. The key principle in the management of this syndrome is to clarify the underlying individual mechanisms to achieve patient-specific treatments. Clinical history, electrocardiogram, cardiac enzymes, echocardiography, coronary angiography and left ventricular angiography represent the first level diagnostic investigations to identify the causes of MINOCA. Regional wall motion abnormalities at left ventricular angiography limited to a single epicardial coronary artery territory identify an 'epicardial pattern'whereas regional wall motion abnormalities extended beyond a single epicardial coronary artery territory identify a 'microvascular pattern'. The most common causes of MINOCA are represented by coronary plaque disease, coronary dissection, coronary artery spasm, coronary microvascular spasm, Takotsubo cardiomyopathy, myocarditis, coronary thromboembolism, other forms of type 2 myocardial infarction and MINOCA of uncertain aetiology. This review aims at summarising the diagnosis and management of MINOCA, according to the underlying physiopathology.

Decreased coronary blood flow velocity in two patients with coronary microvascular spasm: case series†

Introduction

Diagnostic criteria for coronary microvascular spasm (CMS) have not yet been fully established.

Case presentation

We present two cases of CMS in which decreased coronary blood flow velocities were observed during acetylcholine (ACH) provocation tests. The first patient suffered from chest pain occurring while at rest. The patient underwent coronary angiography (CAG), which revealed a decrease in the average peak velocity (APV) from 29 cm/s to 14 cm/s and a slow flow phenomenon following ACH injection. The second patient suffered from chest pain occurring during the night. The patient underwent CAG, which revealed a decrease in the APV from 17 cm/s to 7 cm/s with no significant epicardial coronary artery spasm following ACH injection. Both patients complained of chest pain, and electrocardiogram changes were observed in leads equivalent to the distal area of the vessel during an ACH provocation test. These findings were consistent with CMS, and their conditions improved under medical treatment.

Discussion

A transient decrease in coronary blood flow velocity following ACH administration might be a phenomenon specific to CMS. These cases may provide some insight into the underlying pathophysiology of CMS.

Population-level incidence and outcomes of myocardial infarction with non-obstructive coronary arteries (MINOCA): Insights from the Alberta contemporary acute coronary syndrome patients invasive treatment strategies (COAPT) study

BACKGROUND

Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a known clinical conundrum with limited investigation. Using a large population-based cohort, we examined the incidence, demographic profile, use of evidence-based medicines (EBM) and clinical outcomes of MINOCA patients.

METHODS

Patients hospitalized with a primary diagnosis of MI who underwent coronary angiography between 01/04/2002 and 31/03/2014 in Alberta, Canada, were included in the study. Comparisons were made between patients with MINOCA versus obstructive coronary disease (OCD). The primary composite endpoint was 1-year all-cause death or re-MI.

RESULTS

Of 35,928 patients hospitalized with MI, 2092 (5.8%) had MINOCA. In-hospital mortality rate was 0.8% among MINOCA, and 2.7% among patients with OCD (p < 0.0001). At 6 months, cardiovascular EBM rates were significantly lower among MINOCA patients compared to OCD patients. One-year death/re-MI rate was 5.3% in MINOCA and 8.9% in patients with OCD (adjusted hazard ratio (AHR) 0.75, 95% confidence interval (CI) 0.62-0.92, p < 0.0001). Five-year mortality rates were 10.9% in MINOCA and 16.0% in patients with OCD. Upon further stratification, 770 (36.8%) of MINOCA patients had no angiographic evidence of CAD (i.e. normal angiograms). EBM rates were even lower among these patients. One-year death/re-MI rate among these patients was 3.9% as compared to 6.1% among MINOCA patients with stenosis <50% (AHR 0.68, 95% CI 0.44-1.07, p = 0.028).

CONCLUSIONS

The population-level incidence of MINOCA is approximately 5%. Despite their apparently benign anatomic findings, efforts must be made to improve secondary prevention strategies to reduce the burden of long-term adverse outcomes in this population.

International standardization of diagnostic criteria for microvascular angina

Standardization of diagnostic criteria for ischemic symptoms due to coronary microvascular dysfunction (CMD) is needed for further investigation of patients presenting with anginal chest pain consistent with "microvascular angina" (MVA). At the annual Coronary Vasomotion Disorders International Study Group (COVADIS) Summits held in August 2014 and 2015, the following criteria were agreed upon for the investigative diagnosis of microvascular angina: (1) presence of symptoms suggestive of myocardial ischemia; (2) objective documentation of myocardial ischemia, as assessed by currently available techniques; (3) absence of obstructive CAD (<50% coronary diameter reduction and/or fractional flow reserve (FFR) >0.80) (4) confirmation of a reduced coronary blood flow reserve and/or inducible microvascular spasm. These standardized criteria provide an investigative structure for mechanistic, diagnostic, prognostic and clinical trial studies aimed at developing an evidence base needed for guidelines in this growing patient population. Standardized criteria will facilitate microvascular angina registries and recruitment of suitable patients into clinical trials. Mechanistic research will also benefit from the implementation of standardized diagnostic criteria for MVA.

Targeting the dominant mechanism of coronary microvascular dysfunction with intracoronary physiology tests

The coronary microcirculation plays a key role in modulating blood supply to the myocardium. Several factors like myocardial oxygen demands, endothelial and neurogenic conditions determine its function. Although there is available evidence supporting microvascular dysfunction as an important cause of myocardial ischaemia, with both prognostic and symptomatic implications, its diagnosis and management in clinical practice is still relegated to a second plane. Both diagnostic and therapeutic approaches are hampered by the broadness of the concept of microvascular dysfunction, which fails addressing the plurality of mechanisms leading to dysfunction. Normal microcirculatory function requires both structural integrity of the microcirculatory vascular network and preserved signalling pathways ensuring adequate and brisk arteriolar resistance shifts in response to myocardial oxygen demands. Pathological mechanisms affecting these requirements include structural remodelling of microvessels, intraluminal plugging, extravascular compression or vasomotor dysregulation. Importantly, not every diagnostic technique provides evidence on which of these pathophysiological mechanisms is present or predominates in the microcirculation. In this paper we discuss the mechanisms of coronary microvascular dysfunction and the intracoronary tools currently available to detect it, as well as the potential role of each one to unmask the main underlying mechanism.

Impact of statin therapy on long-term clinical outcomes of vasospastic angina without significant stenosis: A propensity-score matched analysis

BACKGROUND

Limited data are available on the efficacy of statin therapy for secondary prevention in patients with vasospastic angina (VSA). We investigated the association of statin therapy with long-term clinical outcomes in VSA patients without significant coronary artery disease.

METHODS

From January 2003 to June 2014, we enrolled a total of 804 patients with VSA proven by an ergonovine provocation test without significant (≥70% diameter stenosis) coronary artery disease. We classified patients into a statin group (n=330) and a no-statin group (n=474) according to the use of statin. Primary outcome were major adverse cardiovascular events (MACE) defined as a composite of cardiovascular death, myocardial infarction, and any revascularization.

RESULTS

Median follow-up duration was 4.5years (interquartile range: 2.0 to 7.3years). MACE occurred in 14 patients (4.2%) in the statin group, and 21 patients (4.4%) in the no-statin group. There were no differences between the two groups (p=0.97). After 1:1 propensity-score matching (281 pairs), MACE (statin versus [vs.] no-statin; 3.2% vs. 4.3%, hazard ratio [HR]; 0.80, 95% confidence interval [CI]; 0.34-1.89, p=0.60) and readmission due to chest pain (17.1% vs. 17.4%, HR; 1.08, 95% CI; 0.72-1.06, p=0.72) were not statistically different between the two groups.

CONCLUSION

Our results suggest that statin therapy could not improve long-term clinical outcomes in VSA patients without significant coronary artery disease.

Intracoronary Acetylcholine Provocation Testing for Assessment of Coronary Vasomotor Disorders

Intracoronary acetylcholine provocation testing (ACH-test) is an established method for assessment of epicardial coronary artery spasm in the catheterization laboratory which was introduced more than 30 years ago. Due to the short half-life of acetylcholine it can only be applied directly into the coronary arteries. Several studies have demonstrated the safety and clinical usefulness of this test. However, acetylcholine testing is only rarely applied in the U.S. or Europe. Nevertheless, it has been shown that 62% of Caucasian patients with stable angina and unobstructed coronary arteries on coronary angiography suffer from coronary vasomotor disorders that can be diagnosed with acetylcholine testing. In recent years it has been appreciated that the ACH-test not only assesses the presence of epicardial spasm but that it can also be useful for the detection of coronary microvascular spam. In such cases no epicardial spasm is seen after injection of acetylcholine but ischemic ECG shifts are present together with a reproduction of the patient's symptoms during the test. This article describes the experience with the ACH-test and its implementation in daily clinical routine.

Myocardial perfusion echocardiography and coronary microvascular dysfunction

Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking.

Coronary endothelial dysfunction in non-obstructive coronary artery disease: Risk, pathogenesis, diagnosis and therapy

Up to half of patients with signs and symptoms of stable ischemic heart disease have non-obstructive coronary artery disease (NoCAD). Recent evidence demonstrates that two-thirds of patients with NoCAD have demonstrable coronary endothelial dysfunction represented by microvascular or diffuse epicardial spasm following acetylcholine challenge. Patients with coronary endothelial dysfunction are recognized to have significant health services use and morbidity as well as increased risk of developing flow-limiting coronary artery disease and myocardial events, including death. Currently, there are few centers that test for this etiology owing to lack of knowledge, limited evidence for treatment options and invasive diagnostic strategies. This article reviews the pathophysiology, epidemiology, diagnosis and treatment of coronary endothelial dysfunction as a subgroup of NoCAD.

Different definition of microvascular angina

We sometimes encounter patients with microvascular angina (MVA), a disease characterized by anginal pain without abnormal coronary arteriographic findings or coronary spasm. More than 40 years have passed since MVA was first confirmed. The terms 'syndrome X', 'cardiac syndrome X' and 'microvascular dysfunction' have also been used to describe conditions similar to MVA, but all with slightly different definitions. The cause of MVA seems almost certain to be organic and functional abnormalities of the small arteries of the heart. Patients with MVA are likely to suffer from endothelial dysfunction and other microvascular abnormalities of both the coronary and peripheral arteries. The major treatment of MVA has been medication, most often calcium channel blockers. The prognosis of MVA is generally excellent, although symptoms remain in many studies. Some MVA patients with accompanying hypertensive heart disease have gone on to develop progressive left ventricular dysfunction, with poor prognosis. The different definitions applied to the terms used to describe this condition, what we refer to here as MVA, can confound issues involved in diagnosis, prognosis and proper treatment. Therefore, it is extremely important to distinguish primary MVA without underlying heart disease from secondary MVA to explore the disease mechanism and examine the clinical characteristics. It is more than 40 years since Likoff first confirmed this disease; therefore, all researchers know that strict diagnostic criteria for MVA should be immediately established.

Takotsubo cardiomyopathy in two patients with microvascular angina

We present two cases in which takotsubo cardiomyopathy (TC) developed immediately after a diagnosis of microvascular angina had been established. One patient who had been diagnosed as having endothelium-dependent microvascular angina (microvascular spasm) developed TC three weeks after the initial admission. The other patient was diagnosed as having endothelium-independent microvascular angina (decreased coronary flow reserve) and subsequently developed TC after the discontinuation of nicorandil treatment. These cases may provide insight into the possible mechanisms underlying the pathophysiological findings of TC. <Learning objective: Impaired coronary microcirculation has been recently reported in many cases during the acute phase of takotsubo cardiomyopathy. However, the exact mechanism responsible for the coronary microvascular dysfunction associated with this entity remains unclear. This report highlights the importance of microvascular angina, which may play a role in the development of this cardiomyopathy.>.

Microvascular angina: angina that predominantly affects women

In women receiving evaluation for suspected ischemic symptoms, a "normal" diagnosis is five times more common than it is in men. These women are often labeled as having cardiac syndrome X, also known as microvascular angina (MVA). MVA is defined as angina pectoris caused by abnormalities of the small coronary arteries, and is characterized by effort chest pain and evidence of myocardial ischemia with a non-invasive stress test, although the coronary arteries can appear normal or near normal by angiography. MVA patients are often neglected due to the assumption of a good prognosis. However, MVA has important prognostic implications and a proper diagnosis is necessary in order to relieve the patients' symptoms and improve clinical outcomes. The coronary microvasculature cannot be directly imaged using coronary angiography, due to the small diameter of the vessels; therefore, the coronary microvascular must be assessed functionally. Treatment of MVA initially includes standard anti-ischemic drugs (β-blockers, calcium antagonists, and nitrates), although control of symptoms is often insufficient. In this review, we discuss the pathophysiology, diagnosis, and treatment of MVA.

Acute myocardial infarction with no obstructive coronary atherosclerosis: mechanisms and management

Myocardial infarction (MI) with no obstructive coronary atherosclerosis (MINOCA) is a syndrome with different causes. Its prevalence ranges between 5 and 25% of all MIs. The prognosis is extremely variable, depending on the causes of MINOCA. Clinical history, echocardiography, coronary angiography, and left ventriculography represent the first-level diagnostic investigations. Nevertheless, additional tests are required in order to establish its specific cause, thus allowing an appropriate risk stratification and treatment. We review pathogenesis, diagnosis, prognosis, and therapy of MINOCA and propose an algorithm for its management.

Current Diagnostic and Therapeutic Strategies in Microvascular Angina

Microvascular angina is common among patients with signs and symptoms of acute coronary syndrome and is associated with an increased risk of cardiovascular and cerebrovascular events. Unfortunately, microvascular is often under-recognized in clinical settings. The diagnosis of microvascular angina relies on assessment of the functional status of the coronary microvasculature. Invasive strategies include acetylcholine provocation, intracoronary Doppler ultrasound, and intracoronary thermodilution; noninvasive strategies include cardiac positron emission tomography (PET), cardiac magnetic resonance, and Doppler echocardiography. Once the diagnosis of microvascular angina is established, treatment is focused on improving symptoms and reducing future risk of cardiovascular and cerebrovascular events. Pharmacologic options and lifestyle modifications for patients with microvascular angina are similar to those for patients with coronary artery disease.

Gender-specific research for emergency diagnosis and management of ischemic heart disease: proceedings from the 2014 Academic Emergency Medicine Consensus Conference Cardiovascular Research Workgroup

Coronary artery disease (CAD) is the most common cause of death for both men and women. However, over the years, emergency physicians, cardiologists, and other health care practitioners have observed varying outcomes in men and women with symptomatic CAD. Women in general are 10 to 15 years older than men when they develop CAD, but suffer worse postinfarction outcomes compared to age-matched men. This article was developed by the cardiovascular workgroup at the 2014 Academic Emergency Medicine (AEM) consensus conference to identify sex- and gender-specific gaps in the key themes and research questions related to emergency cardiac ischemia care. The workgroup had diverse stakeholder representation from emergency medicine, cardiology, critical care, nursing, emergency medical services, patients, and major policy-makers in government, academia, and patient care. We implemented the nominal group technique to identify and prioritize themes and research questions using electronic mail, monthly conference calls, in-person meetings, and Web-based surveys between June 2013 and May 2014. Through three rounds of nomination and refinement, followed by an in-person meeting on May 13, 2014, we achieved consensus on five priority themes and 30 research questions. The overarching themes were as follows: 1) the full spectrum of sex-specific risk as well as presentation of cardiac ischemia may not be captured by our standard definition of CAD and needs to incorporate other forms of ischemic heart disease (IHD); 2) diagnosis is further challenged by sex/gender differences in presentation and variable sensitivity of cardiac biomarkers, imaging, and risk scores; 3) sex-specific pathophysiology of cardiac ischemia extends beyond conventional obstructive CAD to include other causes such as microvascular dysfunction, takotsubo, and coronary artery dissection, better recognized as IHD; 4) treatment and prognosis are influenced by sex-specific variations in biology, as well as patient-provider communication; and 5) the changing definitions of pathophysiology call for looking beyond conventionally defined cardiovascular outcomes to patient-centered outcomes. These emergency care priorities should guide future clinical and basic science research and extramural funding in an area that greatly influences patient outcomes.

A case of coronary microvascular spasm with slow flow induced by the intracoronary acetylcholine provocation test

Microvascular angina is a rare condition in which myocardial ischemia is caused by microvascular dysfunction without any abnormalities of the epicardial coronary arteries. In clinical practice, it is difficult to diagnose because the microvascular alterations cannot be detected by conventional angiography. Herein we present a rare case of a 67-year-old woman with unstable angina pectoris in whom considerably slow coronary flow was induced by the acetylcholine provocation test with mild epicardial arterial spasm, suggesting the presence of microvascular spasm. Moreover, we show that β-methyl-p-[(123)I]-iodophenyl-pentadecanoic ((123)I-BMIPP) single-photon emission computed tomography imaging is useful for proving myocardial ischemia.

[Gender-specific aspects of coronary heart disease]

The total number of deaths from cardiovascular diseases (CVD) is greater for women than for men, although the mean age at manifestation of CVD is about 10 years older. However, the annual number of cases treated for CVD in acute hospital settings in men exceeds that of women by 50 %. Remarkable gender differences exist in terms of morphological and physiological conditions (e.g. mean coronary vessel diameter; ability to adapt to protective exercise-induced myocardial hypertrophy), as well as of the frequency and clinical significance of somatic risk factors (e.g. smoking). Female body weight increases after menopause and the body shape assumes a more android fat distribution. Women report higher levels of unspecific and affective symptoms. They suffer more from anxiety and depression than men; however, the secondary impact on CVD onset may be less pronounced. The post-acute CVD course is more complicated in women, mainly because they are older and suffer more from multi-morbidity. Whilst male CVD patients aim for a rapid recovery, physical fitness and an increased life expectancy, female patients seek relief from everyday challenges, the maintenance of their independence and emotional support.

Severity of myocardial fatty acid dysmetabolism induced by coronary spasm does not differ with Thrombolysis in Myocardial Infarction (TIMI) grade during intracoronary acetylcholine provocation tests

Whether additional intracoronary acetylcholine (ACH) injections are required for severe coronary spasm without limited coronary flow in the ACH provocation test remains unclear. We used (123)I-β-methyl-iodophenyl pentadecanoic acid ((123)I-BMIPP) to identify myocardial ischemic memory to compare the severity of myocardial fatty acid dysmetabolism among Thrombolysis in Myocardial Infarction (TIMI) grade flow.Thirteen hypertensive volunteers (mean age, 69.5 years) and 37 patients with VSA (mean age, 62.8 years) were enrolled. The patients with VSA were stratified according to TIMI flow grades of 3 (90% luminal narrowing; n = 12) or TIMI 0-2 (≥ 99% or total occlusion; n = 25) during ACH provocation tests. Two weeks after cardiac catheterization, (123)I-BMIPP myocardial scintigraphic images were obtained at 15 minutes (early) and at 4 hours (delayed) after tracer injection. The heart-to-mediastinum (H/M) ratio and washout rates (WR) were calculated from planar images.The TIMI 3 and TIMI 0-2 groups had significantly lower early and delayed H/M ratios than controls but the difference did not reach significance between the two groups (Early: 2.7 ± 0.5 versus 2.3 ± 0.4 and 2.2 ± 0.3, P = 0.024; Delayed: 2.4 ± 0.4 versus 1.8 ± 0.3 and 1.8 ± 0.3, P = 0.001). The washout rate was greater for TIMI 0-2 than the controls.The severity of myocardial fatty acid dysmetabolism did not differ between TIMI 3 and TIMI 0-2 coronary spasms. Additional ACH might not be required considering safety and the severity of coronary spams with TIMI 3 grade flow.

Dihydroergotamine and sumatriptan in isolated human coronary artery, middle meningeal artery and saphenous vein

BACKGROUND

Dihydroergotamine (DHE) and sumatriptan are contraindicated in patients with cardiovascular disease because of their vasoconstricting properties, which have originally been explored in proximal coronary arteries. Our aim was to investigate DHE and sumatriptan in the proximal and distal coronary artery, middle meningeal artery and saphenous vein.

METHODS

Blood vessel segments were mounted in organ baths and concentration response curves for DHE and sumatriptan were constructed.

RESULTS

In the proximal coronary artery, meningeal artery and saphenous vein, maximal contractions to DHE (proximal: 8 ± 4%; meningeal: 32 ± 7%; saphenous: 52 ± 11%) and sumatriptan (proximal: 17 ± 7%; meningeal: 61 ± 18%, saphenous: 37 ± 8%) were not significantly different. In the distal coronary artery, contractions to DHE (5 ± 2%) were significantly smaller than those to sumatriptan (17 ± 9%). At clinically relevant concentrations, mean contractions to DHE and sumatriptan were below 3% in proximal coronary arteries and below 6% in distal coronary arteries. Contractions in the meningeal artery and saphenous vein were higher (7%-38%).

CONCLUSIONS

Contractions to DHE in distal coronary arteries are smaller than those to sumatriptan, while at clinical concentrations they both induce only slight contractions. In meningeal arteries contractions to DHE and sumatriptan are significantly larger, showing their cranioselectivity. Contractions to DHE in the saphenous vein are higher than those in the arteries, confirming its venous contractile properties.

Coronary microvascular dysfunction in women: an overview of diagnostic strategies

Coronary microvascular dysfunction (CMD) also known as syndrome X, is characterized by typical anginal symptoms, evidence of myocardial ischemia on non-invasive testing and normal to minimal coronary disease on coronary angiography. It has a female preponderance and has been detected in up to 50% of women presenting with chest pain symptoms. Definitive diagnosis of CMD is critical as recent evidence suggests that women with this condition are at increased risk of cardiovascular events in the future. Invasive coronary reactivity testing on coronary angiography is considered to be the 'gold standard' for diagnosis of CMD. Non-invasive imaging techniques such as PET and cardiac magnetic resonance hold promise for detection of CMD in the future.

Cranioselectivity of sumatriptan revisited: pronounced contractions to sumatriptan in small human isolated coronary artery

BACKGROUND

Initial concerns about the coronary side-effect potential of the anti-migraine drug sumatriptan and second-generation triptans initiated cranioselectivity studies using proximal human coronary arteries. However, myocardial ischaemia may originate from both large and small human coronary arteries.

METHODS

We investigated the contractions to sumatriptan in proximal (internal diameter 2-3 mm), distal (internal diameter 1,000-1,500 μm) and small (internal diameter 500-1,000 μm) human epicardial coronary arteries and compared these with contractions in the human middle meningeal artery. Concentration response curves to sumatriptan in human coronary arteries were constructed in the absence or presence of the 5-hydroxytryptamine1B (5-HT1B) receptor antagonist SB224289 and the 5-HT1D receptor antagonist BRL15572. The effect of sumatriptan on increased cyclic adenosine monophosphate (cAMP) levels induced by forskolin in proximal and distal coronary artery segments was investigated using a biochemical assay. Western blotting was used to analyse the 5-HT1B receptor density in the human arteries.

RESULTS

Contractions in the proximal human coronary artery were significantly smaller than those in the human meningeal artery, as we showed previously. In contrast, contractions to sumatriptan in distal and small human coronary arteries were not different from those in the human meningeal artery. The 5-HT1B receptor antagonist SB224289, but not the 5-HT1D receptor antagonist BRL15572, inhibited the contraction induced by sumatriptan in the coronary arteries. Moreover, in distal, but not in proximal, coronary arteries, sumatriptan inhibited the increase in cAMP levels induced by forskolin. Contrary to our expectations, the 5-HT1B receptor expression was more pronounced in the proximal human coronary artery than in the distal and small human coronary artery.

CONCLUSIONS

Based on functional experiments in distal and small human coronary arteries, contractions to sumatriptan are not as cranioselective as previously assumed. However, the vast clinical experience with sumatriptan and other triptans has proven that these drugs are cardiovascularly safe when contraindications are taken into account.

Clinical usefulness, angiographic characteristics, and safety evaluation of intracoronary acetylcholine provocation testing among 921 consecutive white patients with unobstructed coronary arteries

BACKGROUND

Coronary spasm can cause myocardial ischemia and angina in patients with and those without obstructive coronary artery disease. However, provocation tests using intracoronary acetylcholine administration are rarely performed in clinical routine in the United States and Europe. Thus, we assessed the clinical usefulness, angiographic characteristics, and safety of intracoronary acetylcholine provocation testing in white patients with unobstructed coronary arteries.

METHODS AND RESULTS

From September 2007 to June 2010, a total of 921 consecutive patients (362 men, mean age 62±12years) who underwent diagnostic angiography for suspected myocardial ischemia and were found to have unobstructed coronary arteries (no stenosis ≥50%) were enrolled. The intracoronary acetylcholine provocation testing was performed directly after angiography according to a standardized protocol. Three hundred forty-six patients (35%) reported chest pain at rest, 222 (22%) reported chest pain on exertion, 238 (24%) reported a combination of effort and resting chest pain, and 41 (4%) presented with troponin-positive acute coronary syndrome. The overall frequency of epicardial spasm (>75% diameter reduction with angina and ischemic ECG shifts) was 33.4%, and the overall frequency of microvascular spasm (angina and ischemic ECG shifts without epicardial spasm) was 24.2%. Epicardial spasm was most often diffuse and located in the distal coronary segments (P<0.01). No fatal or irreversible nonfatal complications occurred. However, 9 patients (1%) had minor complications (nonsustained ventricular tachycardia [n=1], fast paroxysmal atrial fibrillation [n=1], symptomatic bradycardia [n=6], and catheter-induced spasm [n=1]).

CONCLUSIONS

Epicardial and microvascular spasm are frequently found in white patients with unobstructed coronary arteries. Epicardial spasm is most often diffuse and located in the distal coronary segments. The intracoronary acetylcholine provocation test is a safe technique to assess coronary vasomotor function.

Advances in mechanisms, imaging and management of the unstable plaque

Post-mortem observations demonstrated that plaque fissure was the final event leading to coronary thrombosis and occlusion in about two-thirds of cases of sudden coronary death. Plaques prone to fissure have, therefore, been defined "vulnerable plaques" and are identified by specific anatomic features including thin inflamed fibrous cap, large lipidic core and positive remodeling. Accordingly, elegant imaging modalities have been developed in order to identify this "holy grail". However, the results of prognostic studies based on the identification of vulnerable plaques have not been encouraging because of the low positive predictive value for major cardiovascular events. This observation is not surprising as the pathogenesis of acute coronary syndromes is complex and multifactorial. In this review we propose a pathogenetic classification of acute coronary syndromes in the attempt to identify homogeneous groups of patients with a common mechanism of coronary instability which can be identified by using specific biomarkers and imaging techniques, and become a specific therapeutic target.

A case of vasospastic angina in which the ergonovine provocation test with intracoronary isosorbide dinitrate and nicorandil was effective in the diagnosis of microvascular spasm

A 60-year-old man was admitted with early morning angina while at rest. Coronary angiogram revealed no organic lesions; therefore, a spasm provocation test with ergonovine was performed. Administration of intracoronary ergonovine induced total occlusion of the right coronary artery. The induced total occlusion improved but coronary flow velocity remained severely reduced and chest discomfort with ST-T changes in ECG remained in spite of repeated administration of isosorbide dinitrate (ISDN). Intracoronary administration of nicorandil following ISDN alleviated the chest discomfort, normalized the ST-T change in ECG, and improved the coronary flow. This suggested that microvascular spasm and the epicardial spasm were not relieved by ISDN but by nicorandil. Intracoronary nicorandil injection following ISDN administration may be useful for the diagnosis of microvascular spasm in the ergonovine provocation test.

Impact of chronic emotional stress on myocardial function in postmenopausal women and its relationship with endothelial dysfunction

Background and Objectives

An association between chronic stress and cardiovascular diseases has been described, but the underlying mechanisms have not been fully elucidated. We investigate the impact of perceived stress on the left ventricular (LV) and endothelial functions in postmenopausal women.

Subjects and Methods

We investigated 64 consecutive postmenopausal women (mean age 56.7±9.7 years) with atypical chest pain and chronic stress. Patients with coronary heart disease were excluded. Global and segmental longitudinal deformation parameters of LV were used as parameters to assess myocardial function and brachial flow-mediated dilatation (FMD) was used to assess the endothelial function, and patients were analyzed by the Symptom Checklist 90 Revised (SCL-90-R) to determine emotional stress. The study participants were divided into two groups, based on global severity index (GSI): ≥50 (group A, n=27) or <50 (group B, n=37).

Results

Although there were no significant differences in LV geometry or myocardial performance indices between the groups, global LV strain was significantly reduced in group A compared to group B (-16.6±2.7% vs. -19.1±1.9%, p=0.001). There were also significant differences in the value of reactive FMD (6.6±2.2% vs. 9.5±2.9%, p<0.001), and same result was observed for nitroglycerine-induced dilatation (14.6±4.7% vs. 18.0±5.8%, p=0.016). Multivariate linear regression analysis showed that GSI was the only significant attributor to global LV strain (β=0.149, p=0.008) and reactive FMD (β=-0.200, p=0.041).

Conclusion

Chronic emotional stress may exert negative effects on the LV and endothelial functions, which may be associated with the severity of stress. This study provides a possible mechanism by which stress is associated with an increased risk of cardiovascular dysfunction.