Abnormal myocardial phosphorus-31 nuclear magnetic resonance spectroscopy in women with chest pain but normal coronary angiograms

Exercise-induced myocardial ischemia detected by cardiopulmonary exercise testing

Cardiopulmonary exercise testing (CPET) is a well-accepted physiologic evaluation technique in patients diagnosed with heart failure and in patients presenting with unexplained dyspnea on exertion. Several variables obtained during CPET, including oxygen consumption relative to heart rate and work rate provide consistent, quantitative patterns of abnormal physiologic responses to graded exercise when left ventricular dysfunction is caused by myocardial ischemia. This concept report describes both the methodology and clinical application of CPET associated with myocardial ischemia. Initial evidence indicates left ventricular dysfunction induced by myocardial ischemia may be accurately detected by an abnormal CPET response. CPET testing may complement current noninvasive testing modalities that elicit inducible ischemia. It provides a physiologic quantification of the work rate, heart rate, and O(2) uptake at which myocardial ischemia develops. In conclusion, adding CPET with gas exchange measurements is likely to be of value in diagnosing and quantifying both overt and occult myocardial ischemia and its reversibility with treatment.

Cardiac syndrome X: a brief overview for nurses

Cardiac syndrome X is characterized by typical anginal symptoms and a positive exercise stress test in patients with normal coronary arteries confirmed by angiography. It is a relatively common condition seen by nurses working with patients undergoing cardiac catheterization. This article briefly describes the condition, pathophysiology, and treatment options. Nursing interventions in the care of these patients are also discussed.

How to improve noninvasive coronary artery disease diagnostics in premenopausal women? The influence of menstrual cycle on ST depression, left ventricle contractility, and chest pain observed during exercise echocardiography in women with angina and normal coronary angiogram

BACKGROUND

The aim was to assess the influence of menstrual cycle on results of exercise echocardiography and electrocardiography.

METHODS

Premenopausal women (n=28) with regular monthly menses, presented typical angina, positive electrocardiogram (ECG) exercise stress test, and normal coronary angiogram were recruited. Exercise supine bicycle echocardiography with simultaneous recording of 12-lead ECG was performed once a week for 4 consecutive weeks. Occurrence of angina, time to angina, time to significant ST deviation, and segmental myocardial contractility were analyzed. Blood samples were drawn to estimate follicle-stimulating hormone, luteinizing hormone, beta-estradiol, progesterone concentration and confirm the position in menstrual cycle. In correlation analysis, linear and logistic regression were used as appropriate. Qualitative variables were categorized into quartiles in logistic regression analysis.

RESULTS

Exercise ST depression was more frequently observed in both luteal phases (early luteal 78%, late luteal 86%) compared to the late follicular phase (50%, P<.05). Time to ST depression was significantly longer in late follicular phase compared to other phases. The rate of segmental exercise left ventricular hypokinesis was low and not significantly related to menstrual cycle. Using linear regression, significant positive correlation was found between estradiol-progesterone ratio and time to ST depression. Using multiple logistic regression, we confirmed that progesterone level is independent factor influencing the presence of ST depression.

CONCLUSION

In women with typical angina and normal coronary angiogram, the position in menstrual cycle influences the ST depression but not myocardial contractility during exercise echocardiography.

Risk prediction of coronary heart disease based on retinal vascular caliber (from the Atherosclerosis Risk In Communities [ARIC] Study)

Recent studies showed that such retinal vascular signs as quantitative retinal vascular caliber were associated with increased risk of incident coronary heart disease (CHD), but whether these retinal vascular signs add to the prediction of CHD over and above traditional CHD risk factors was not addressed. Whether these signs add to the prediction of CHD over and above the Framingham risk score in people (n = 9,155) without diabetes selected from the ARIC Study was investigated. Incident CHD was ascertained using standardized methods, and retinal vascular caliber and other retinal signs were measured from retinal photographs. After a mean of 8.8 years of follow-up, there were 700 incident CHD events. Women with wider retinal venular caliber (hazard ratio 1.27/1-SD increase, 95% confidence interval 1.08 to 1.50) and narrower retinal arteriolar caliber (hazard ratio 1.31/1-SD decrease, 95% confidence interval 1.10 to 1.56) had a higher risk of incident CHD after adjusting for Framingham risk score variables. Area under the receiver operator characteristic curve increased from 0.695 to 0.706 (1.7% increase) with the addition of retinal vascular caliber to the Framingham risk model. Risk prediction models with and without retinal vascular caliber both fitted the data and were well calibrated for women. In men, retinal vascular caliber was not associated with CHD risk after adjustment. Other retinal vascular signs were not associated with 10-year incident CHD in men or women. In conclusion, although retinal vascular caliber independently predicted CHD risk in women, the incremental predictive ability over that of the Framingham model was modest and unlikely to translate meaningfully into clinical practice.

Diabetes increases large artery diseases, but not small artery diseases in the brain

BACKGROUND

It is established that diabetes causes various systemic micro- and macro-vascular complications. Little has been, however, studied on the differential effects of diabetes on the large artery diseases (LAD) or small artery disease (SAD) in the brain. The purpose of this study was to examine an association of diabetes on the incidence of underlying LAD versus SAD in ischemic stroke patients.

METHODS

We prospectively collected 523 acute ischemic stroke patients without cardioembolic causes or other determined causes of stroke. Using brain MRI, the cerebral LAD (extracranial and intracranial arterial stenosis of 50 % or more) and the cerebral SAD (old lacunar infarction, microbleeds and leukoaraiosis) findings were assessed. Information regarding vascular risk factor was also collected.

RESULTS

Among the patients (male, n = 342; diabetes, n = 200), diabetes was not associated with the presence of LADs or SADs in female subjects, but strongly with the presence of intracranial LAD in male subjects (p < 0.01). The association remained significant (OR 2.09, 95 %CI 1.25-3.51) after adjusting for major confounders. A similar association was also found in intracranial LAD and insulin resistance. There was, however, no significant association of diabetes with SAD in male nor in female patients.

CONCLUSIONS

Our results showed that diabetes is associated with the frequency of intracranial LAD, especially in males. Out study may be regarded as evidence of differential biological effects of diabetes on cerebral vasculature.

Prevalence of Angina in Women Versus Men

Background— In the absence of previous international comparisons, we sought to systematically evaluate, across time and participant age, the sex ratio in angina prevalence in countries that differ widely in the rate of mortality due to myocardial infarction.

Methods and Results— We searched MEDLINE and EMBASE until February 2006 for healthy population studies published in any language that reported the prevalence of angina (Rose questionnaire) in women and men. We obtained myocardial infarction mortality rates from the World Health Organization. A total of 74 reports of 13 331 angina cases in women and 11 511 cases in men from 31 countries were included. Angina prevalence varied widely across populations, from 0.73% to 14.4% (population weighted mean 6.7%) in women and from 0.76% to 15.1% (population weighted mean 5.7%) in men, and was strongly correlated within populations between the sexes ( r =0.80, P <0.0001). Angina prevalence showed a small female excess with a pooled random-effects sex ratio of 1.20 (95% CI 1.14 to 1.28, P <0.0001). This female excess was found across countries with widely differing myocardial infarction mortality rates in women (interquartile range 12.7 to 126.5 per 100 000), was particularly high in the American studies (1.40, 95% CI 1.28 to 1.52), and was higher among nonwhite ethnic groups than among whites. This sex ratio did not differ significantly by participant’s age, the year the survey began, or the sex ratio for mortality due to myocardial infarction.

Conclusions— Over time and at different ages, independent of diagnostic and treatment practices, women have a similar or slightly higher prevalence of angina than men across countries with widely differing myocardial infarction mortality rates.

Adrenergic gene polymorphisms and cardiovascular risk in the NHLBI-sponsored Women's Ischemia Syndrome Evaluation

BACKGROUND

Adrenergic gene polymorphisms are associated with cardiovascular and metabolic phenotypes. We investigated the influence of adrenergic gene polymorphisms on cardiovascular risk in women with suspected myocardial ischemia.

METHODS

We genotyped 628 women referred for coronary angiography for eight polymorphisms in the alpha1A-, beta1-, beta2- and beta3-adrenergic receptors (ADRA1A, ADRB1, ADRB2, ADRB3, respectively), and their signaling proteins, G-protein beta 3 subunit (GNB3) and G-protein alpha subunit (GNAS). We compared the incidence of death, myocardial infarction, stroke, or heart failure between genotype groups in all women and women without obstructive coronary stenoses.

RESULTS

After a median of 5.8 years of follow-up, 115 women had an event. Patients with the ADRB1 Gly389 polymorphism were at higher risk for the composite outcome due to higher rates of myocardial infarction (adjusted hazard ratio [HR] 3.63, 95% confidence interval [95%CI] 1.17-11.28; Gly/Gly vs. Arg/Arg HR 4.14, 95%CI 0.88-19.6). The risk associated with ADRB1 Gly389 was limited to those without obstructive CAD (n = 400, Pinteraction = 0.03), albeit marginally significant in this subset (HR 1.71, 95%CI 0.91-3.19). Additionally, women without obstructive CAD carrying the ADRB3 Arg64 variant were at higher risk for the composite endpoint (HR 2.10, 95%CI 1.05-4.24) due to subtle increases in risk for all of the individual endpoints. No genetic associations were present in women with obstructive CAD.

CONCLUSION

In this exploratory analysis, common coding polymorphisms in the beta1- and beta3-adrenergic receptors increased cardiovascular risk in women referred for diagnostic angiography, and could improve risk assessment, particularly for women without evidence of obstructive CAD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00000554.

Relation between stress-induced myocardial perfusion defects on cardiovascular magnetic resonance and coronary microvascular dysfunction in patients with cardiac syndrome X

OBJECTIVES

The purpose of this study was to investigate whether a direct relation can be demonstrated between myocardial perfusion defects detected during dobutamine stress test (DST) by cardiovascular magnetic resonance (CMR) and impairment of coronary microvascular dilatory function in patients with cardiac syndrome X (CSX).

BACKGROUND

Despite the fact that coronary microvascular dysfunction has been shown in most patients with CSX, the ischemic origin of CSX remains debated. No previous study assessed whether a strict relation exists between abnormalities in myocardial perfusion and coronary microvascular dysfunction in CSX patients.

METHODS

Eighteen CSX patients (mean age 58 +/- 7 years, 7 men) and 10 healthy control subjects (mean age 54 +/- 8 years, 4 men) underwent myocardial perfusion study by gadolinium-enhanced CMR at rest and at peak DST (maximal dose 40 microg/kg/min). Coronary flow response (CFR) to adenosine (140 microg/kg/min in 90 s) in the left anterior descending (LAD) coronary artery was assessed by high-resolution transthoracic echo-Doppler and expressed as the ratio between coronary flow velocity at peak adenosine and at rest.

RESULTS

At peak DST, reversible perfusion defects on CMR were found in 10 CSX patients (56%) but in none of the control subjects (p = 0.004). The CFR to adenosine in the LAD coronary artery was lower in CSX patients than in control subjects (2.03 +/- 0.63 vs. 3.29 +/- 1.0, p = 0.0004). The CSX patients with DST-induced myocardial perfusion defects in the LAD territory on CMR had a lower CFR to adenosine compared with those without perfusion defects in the LAD territory (1.69 +/- 0.5 vs. 2.31 +/- 0.6, p = 0.01). A significant correlation was found in CSX patients between CFR to adenosine and a DST perfusion defect score on CMR in the LAD territory (r = -0.45, p = 0.019).

CONCLUSIONS

Our data concurrently show DST-induced myocardial perfusion defects on CMR and reduced CFR in the LAD coronary artery territory in CSX patients, thus giving strong evidence that a dysfunction of coronary microcirculation resulting in myocardial perfusion abnormalities is present in these patients.

Angina with "normal" coronary arteries: sex differences in outcomes

BACKGROUND

Several studies have demonstrated that women with nonobstructive coronary disease have a high rate of subsequent investigations, rehospitalizations for recurrent chest pain, and repeat coronary angiography. The sex specificity of this finding is unclear. We therefore undertook an evaluation of sex differences in rehospitalization for acute coronary syndrome (ACS) or chest pain in patients with "angiographically normal" coronaries.

METHODS

A retrospective cohort study using prospectively collected angiographic and clinical data on all patients in British Columbia, Canada, presenting for their first cardiac catheterization with suspected ischemic heart disease but angiographically normal coronaries.

RESULTS

Among 32,856 patients, 7.1% of men versus 23.3% of women were angiographically normal (P < .001). Among angiographically normal patients, women were older and more likely to present with hypertension, prior stroke, chronic obstructive pulmonary disease, and peripheral vascular disease than men, but Canadian Cardiovascular Society class of angina did not vary by sex. Within 1 year, 1.0% died, (19 women, 18 men, P = .27) and 0.6% had a stroke (13 women, 9 men, P = .91). Readmission to hospital for ACS or chest pain requiring catheterization was significantly higher in women compared to men (adjusted OR 4.06; 95% CI 1.15-14.31).

CONCLUSIONS

In a contemporary, population-based cohort presenting for cardiac catheterization for suspected ischemia, women with angiographically normal coronaries were >4 times more likely to be readmitted to hospital for ACS/chest pain within 180 days compared to men. The observed sex difference has important social and economic implications and suggests that traditional diagnostic methods may not be optimal for women.

Diagnostic strategies for heart disease in women: an update on imaging techniques for optimal management

Significant progress has been made toward increasing awareness of the risks of heart disease in women and in the area of sex-specific cardiovascular research. Yet, coronary artery disease remains the leading cause of death of women in the western world. Over the last decade, the increased research focus of women at risk for ischemic heart disease has helped in defining and delineating some of the sex-specific factors, which have adversely affected the accuracy of imaging techniques in women. A focused body of clinical research has been published over the last few years, and there now exists a growing body of evidence on the diagnostic and prognostic accuracy of contemporary cardiovascular imaging techniques in women. Recent publications specifically addressing this issue [namely the 2005 American Heart Association Statement on Cardiac Imaging in Women, and the 2006 Women's Ischemia Syndrome Evaluation (WISE) study] are now changing the existing paradigm of ischemic heart disease from one representing a "man's disease," to one including sex-specific algorithms. In this article we review the literature regarding the diagnostic and prognostic evaluation of coronary artery disease in women with respect to imaging.

Increased mediastinal fat and impaired left ventricular energy metabolism in young men with newly found fatty liver

Fatty liver is characterized by metabolic abnormalities at the liver, but also at skeletal muscle and adipose tissue sites. It is hypothesized that the heart may be suffering metabolic alterations, and this study was undertaken to ascertain whether individuals with fatty liver have left ventricular (LV) alterations of energy metabolism, structure, and function and abnormal amounts of epicardial fat as a specific marker of visceral fat accumulation. To this end we studied young, nondiabetic men matched for anthropometric features with (n = 21) or without (n = 21) fatty liver by means of (1) cardiac magnetic resonance imaging (MRI); (2) cardiac (31)P-MR spectroscopy (MRS); and (3) hepatic (1)H-MRS to assess quantitatively the intrahepatic fat (IHF) content. Insulin sensitivity was determined by the updated HOMA-2 computer model. Individuals with fatty liver showed reduced insulin sensitivity, increased serum free fatty acid (FFA), and E-selectin, abnormal adipokine concentrations, and higher blood pressure. LV morphology and systolic and diastolic functions were not different; however, in the scanned intrathoracic region, the intrapericardial (7.8 +/- 3.1 versus 5.9 +/- 2.5 cm(2); P < 0.05) and extrapericardial (11.7 +/- 6.1 versus 7.8 +/- 3.2 cm(2); P < 0.03) fat was increased in men with fatty liver compared with those without fatty liver. The phosphocreatine (PCr)/adenosine triphosphate (ATP) ratio, a recognized in vivo marker of myocardial energy metabolism, was reduced in men with fatty liver in comparison with normals (1.85 +/- 0.35 versus 2.11 +/- 0.31; P < 0.016). In conclusion, in newly found individuals with fatty liver, fat was accumulated in the epicardial area and despite normal LV morphological features and systolic and diastolic functions, they had abnormal LV energy metabolism.

Ischemia in women with angina and normal coronary angiograms

BACKGROUND

Coronary artery disease is frequent in postmenopausal women. Myocardial ischemia has been induced with stress testing, and a relationship between endothelial dysfunction and perfusion defects has been reported.

OBJECTIVE

To evaluate whether myocardial ischemia can be evidenced both by perfusion and function abnormalities using gated single-photon emission computed-tomography myocardial scintigraphy with technetium-labeled compounds in women with typical angina, normal coronary angiography, and endothelial dysfunction.

METHODS AND RESULTS

Fifty-nine postmenopausal patients were studied. Each underwent technetium-99m methoxy-isobutyl-isonitrile myocardial scintigraphy (protocol: exercise stress-rest), brachial artery endothelial function measured by ultrasonography, lipidogram, and 24-h ambulatory ECG recording (Holter). Twenty-one patients (group I) showed perfusion defects in myocardial scintigraphy, whereas the other 38 patients (group II) did not. Group I patients exhibited endothelial dysfunction more frequently (57 vs. 29%) than those of group II. Among group I patients, 12 showed a reversible perfusion defect that, in 75% of the cases, was associated with poststress left ventricular ejection fraction reduction greater than 5% and a regional hypokinesis. Nine patients had fixed defects, which in 56% of the cases were associated with poststress left ventricular ejection fraction reduction greater than 5%. Left ventricular ejection fraction poststress minus left ventricular ejection fraction at rest was -5.2% in group I patients versus -1.8% in group II (P<0.001). Three patients in group I showed evidence of ischemia by Holter compared with four in group II.

CONCLUSION

Stress-induced ischemia is associated with poststress left ventricular ejection fraction reduction in postmenopausal women with typical angina, normal coronary angiography, and a trend toward abnormal endothelial-mediated vasodilation.

Reviewing myocardial silent ischemia: specific patient subgroups

Silent myocardial ischemia (SMI) is a relatively common, yet poorly understood, clinical entity. The most accurate means of detecting SMI and the precise treatment endpoints remain unclear. However, the presence of SMI correlates with the likelihood of future adverse cardiac events. Evidence suggests that patients at high risk of severe cardiac ischemia, even with the absence of symptoms, derive the greatest benefit from an aggressive diagnostic and therapeutic approach. This paper is giving a detailed review of SMI in regards to specific patient subgroups, i.e. populations with diabetes mellitus, hypertension, elderly patients, post-revascularization patients, women, the suggested screening procedures for each subgroup, as well as the emersion of new markers for the selection of high-risk patients for screening.

Future directions in MR imaging of the female pelvis

New technology continues to change the field of MR imaging. This article describes select areas of technical development that are likely to have an increasing clinical impact on MR imaging of the female pelvis, including high-field imaging, parallel imaging, contrast agents, diffusion-weighted imaging and spectroscopy, and MR-guided intervention.

Myocardial perfusion imaging by cardiac magnetic resonance

Cardiovascular magnetic resonance (CMR) has been shown to provide high quality data on cardiac and valvular function, perfusion, viability, blood flow, and potentially, on cardiac metabolism as well. Several of these CMR applications (eg, function and viability assessment) matured during the past years and are now established components of a cardiac workup. Perfusion-CMR is close to this status and is already a major contributor to cardiac examinations in a growing number of expert centers. Large multicenter perfusion-CMR trials comparing the diagnostic performance of CMR with other techniques were recently reported yielding areas under the receiver-operator-characteristics curve as a high as 0.85 for coronary artery disease detection (MR-IMPACT). Anticipating a growing role for perfusion-CMR in cardiology in the near future, this article discusses the principles of perfusion-CMR and its integration into the workup of patient with coronary artery disease (CAD). In addition to a functional study, this integration is mainly composed of a perfusion-CMR part, followed by a viability assessment by late enhancement CMR techniques. The principal characteristics of these CMR techniques are compared with those of single photon emission computed tomography (SPECT) and positron emission tomography (PET). After introduction into principles and techniques of perfusion-CMR, some open questions in perfusion-CMR and challenges for the future are addressed. Finally, newer CMR applications are shortly mentioned utilizing hyperpolarized carbon-13 compounds in experimental models for quantification of myocardial perfusion and for real-time assessment of metabolic pathways in postischemic myocardium.

Assessment of coronary flow reserve by sestamibi imaging in patients with typical chest pain and normal coronary arteries

PURPOSE

We assessed coronary flow reserve (CFR) by sestamibi imaging in patients with typical chest pain, positive exercise stress test and normal coronary vessels.

METHODS

Thirty-five patients with typical chest pain and normal angiogram and 12 control subjects with atypical chest pain underwent dipyridamole/rest (99m)Tc-sestamibi imaging. Myocardial blood flow (MBF) was estimated by measuring first transit counts in the pulmonary artery and myocardial counts from SPECT images. Estimated CFR was expressed as the ratio of stress to rest MBF. Rest MBF and CFR were corrected for rate-pressure product (RPP) and expressed as normalised MBF (MBF(n)) and normalised CFR (CFR(n)). Coronary vascular resistances (CVR) were calculated as the ratio between mean arterial pressure and estimated MBF.

RESULTS

At rest, estimated MBF and MBF(n) were lower in controls than in patients (0.98 +/- 0.4 vs 1.30 +/- 0.3 counts/pixel/s and 1.14 +/- 0.5 vs 1.64 +/- 0.6 counts/pixel/s, respectively, both p < 0.02). Stress MBF was not different between controls and patients (2.34 +/- 0.8 vs 2.01 +/- 0.7 counts/pixel/s, p=NS). Estimated CFR was 2.40 +/- 0.3 in controls and 1.54 +/- 0.3 in patients (p < 0.0001). After correction for the RPP, CFR(n) was still higher in controls than in patients (2.1 +/- 0.5 vs 1.29 +/- 0.5, p < 0.0001). At baseline, CVR values were lower (p < 0.01) in patients than in controls. Dipyridamole-induced changes in CVR were greater (p < 0.0001) in controls (-63%) than in patients (-35%). In the overall study population, a significant correlation between dipyridamole-induced changes in CVR and CFR was observed (r = -0.88, p < 0.0001).

CONCLUSION

SPECT might represent a useful non-invasive method for assessing coronary vascular function in patients with angina and a normal coronary angiogram.

MDCT in Early Triage of Patients with Acute Chest Pain

OBJECTIVE

Current risk stratification of patients with acute chest pain but normal initial cardiac enzymes and nondiagnostic ECG is inefficient. We sought to determine whether contrast-enhanced MDCT-based detection of stenosis is feasible and improves early and accurate triage of patients with acute chest pain.

SUBJECTS AND METHODS

We studied 40 patients (53% men; mean age, 57 +/- 13 years) with chest pain who were awaiting hospital admission to rule out an acute coronary syndrome (ACS) despite the absence of diagnostic ECG changes and normal cardiac enzymes on emergency department presentation. Patients underwent contrast-enhanced MDCT before hospital admission. Afterward, patients received standard clinical care. All physicians involved in the patients' care were blinded to the results of MDCT. An expert panel established the presence or absence of ACS based on American Heart Association (AHA) guidelines. The MDCT images were evaluated for the presence of significant coronary artery stenosis (diameter reduction > 50%) and were used to make a triage decision.

RESULTS

All five patients (12.5%) with ACS (one with non-ST elevation myocardial infarction, four with unstable angina pectoris) had at least one significant coronary stenosis on MDCT (sensitivity, 100% [95% CI, 49-100%)]. ACS was ruled out in 35 patients (87.5%). Significant coronary stenosis was excluded in 26 of the 35 patients without ACS by MDCT (specificity, 74% [CI, 75-88%]), potentially saving 70% of unnecessary hospital admissions.

CONCLUSION

MDCT-based detection of significant coronary stenoses has tremendous potential to decrease the number of unnecessary hospital admissions, without reducing appropriate admission rates, in patients with chest pain who have nondiagnostic ECG results and normal cardiac enzymes. These results are likely to further improve with advances in MDCT technology.

Increased aortic pulse and fractional pulse pressures in patients with cardiac syndrome X

BACKGROUND

Angina with normal coronary arteries, cardiac syndrome X, is a diagnosis of exclusion. The exact mechanism of this clinical syndrome remains unclear. Although the prognosis is as good as equal to that of the normal population, symptoms related to the syndrome largely impair quality of life. Aortic pulse and fractional pulse pressures are strong and independent indicators of the risk of coronary heart disease. An increase in these hemodynamic parameters is significantly associated with the presence of coronary artery disease in men and women.

METHODS AND RESULTS

We evaluated aortic pulse and fractional pulse pressures of patients with cardiac syndrome X and control subjects, and investigated the relation between the two groups. One hundred and twenty-six patients with cardiac syndrome X with a mean age of 53.1 +/- 9.5 years and 76 patients without the syndrome with a mean age of 53.1+/-11.2 years were studied consecutively from May 2004 to May 2005. Aortic systolic, diastolic, mean and pulse pressures were measured and the fractional pulse pressure was calculated (aortic pulse pressure/mean pressure). Aortic pulse and fractional pulse pressures were significantly higher in the cardiac syndrome X group than in the control group (51 +/- 13 mmHg and 43+/-9 mmHg, p < 0.001; 0.54 +/- 0.11 and 0.47 +/- 0.08, p < 0.001, respectively). All patients were classified into tertiles of aortic pulse pressure level to evaluate whether aortic pulse pressure was associated with the presence of cardiac syndrome X in the study. The multiple-adjusted odds ratio of the risk of cardiac syndrome X was 6.72 (95% CI 2.76-16.37) for tertile 2 and 29.94 (95% CI 5.59-160.44) for tertile 3 of aortic pulse pressure level compared with tertile 1. In addition, all patients were divided into two groups as lower and higher levels of aortic fractional pulse pressure. The multiple-adjusted OR of the risk of cardiac syndrome X was 4.09 (95% CI 2.05-8.15) for the higher group compared with the lower group of aortic fractional pulse pressure level.

CONCLUSION

Ascending aorta pulse and fractional pulse pressures are significantly associated with the presence of cardiac syndrome X and these associations are independent of age and other cardiovascular risk factors.

Therapeutic implications of the gender-specific aspects of cardiovascular disease

The manifestations of cardiovascular diseases differ between men and women, as do outcomes after therapeutic interventions. It is important that those involved in drug discovery and development, as well as disease treatment, are aware of these differences because such variations are likely to have an increasing role in therapeutic decisions in the future. Here, I review gender differences in the most frequent cardiovascular diseases and their underlying sex-dependent molecular pathophysiology, and discuss gender-specific effects of current cardiovascular drugs and the implications for novel strategies for drug development.

Retinal vascular calibre and the risk of coronary heart disease-related death

OBJECTIVE

To examine whether retinal vascular calibre independently predicts risk of coronary heart disease (CHD) -related death.

METHODS

In a population-based cohort study of 3654 Australians aged > or = 49 years, retinal arteriolar and venular calibres were measured from baseline retinal photographs and the arteriole to venule ratio (AVR) was calculated. CHD-related death was confirmed from the Australian National Death Index.

RESULTS

Over nine years, 78 women (4.1%) and 114 men (7.8%) had incident CHD-related deaths. In people aged 49-75 years, wider venules were associated with CHD death, with relative risk (RR) 1.8 (95% confidence interval (CI) 1.1 to 2.7) and RR 2.0 (95% CI 1.1 to 3.6) per standard deviation (SD) increase in venular calibre for men and women, respectively, after adjustment for traditional risk factors. Additionally, in women aged 49-75 years, smaller AVR and narrower arterioles were associated with CHD death (RR 1.5, 95% CI 1.1 to 2.2, and RR 1.9, 95% CI 1.0 to 3.5 per SD decrease in AVR and arteriolar calibre, respectively, after adjustment). These associations were not observed in people aged > 75 years.

CONCLUSIONS

These findings suggest that microvascular disease processes may have a role in CHD development in middle-aged people, particularly in women. Retinal photography may be useful in cardiovascular risk prediction.

Functional and Bioenergetic Consequences of AT1 Antagonist Olmesartan Medoxomil in Hearts With Postinfarction LV Remodeling

The structural left ventricular (LV) remodeling and contractile dysfunction of hearts with postinfarction LV remodeling are benefited by angiotensin II type 1 receptor (AT1) blocker. However, the myocardial bioenergetic consequences of AT1 blocker in these hearts are not known. To investigate, we used a porcine model of postinfarction LV remodeling produced by ligation of the left circumflex coronary artery. After infarction, 7 pigs received olmesartan medoxomil (2 mg/kg) for comparison against 9 untreated and 10 normal pigs. Measurements of hemodynamics, myocardial perfusion, and myocardial bioenergetics were taken 7 weeks postinfarction. The treated group had an LV-to-body weight ratio significantly lower than the untreated group (2.69 +/- 0.70, 2.96 +/- 0.51, 3.66 +/- 0.60 g/kg for control, treated, and untreated groups, respectively). The untreated group had a mean aortic pressure significantly higher than the control (73 +/- 16, 86 +/- 14, and 94 +/- 20 mm Hg, respectively). The subendocardial phosphocreatine-to-ATP ratios of the treated group were significantly higher than that of the untreated group. The untreated group, but not the treated group, had significant reductions in mitochondrial F0F1-ATPase subunits compared with controls. Congestive heart failure as evidenced by significant ascites (100 to 2000 mL) developed in 4 of the 9 untreated animals, but was absent in the treated group. Animals with heart failure demonstrated reductions in both mitochondrial F0F1-ATPase expression and myocardial high-energy phosphate levels. Thus, severe LV dysfunction and accompanying abnormal myocardial bioenergetic phenotype were prevented by the AT1 antagonist olmesartan medoxomil.

Cardiac syndrome X in women: the role of oestrogen deficiency

Cardiac syndrome X (CSX), defined as typical exertional chest pain, a positive response to stress testing, and normal coronary arteriograms, encompasses different pathogenic subgroups. Both cardiac and non-cardiac mechanisms have been suggested to play a pathogenic role, and it has been shown that the syndrome is associated with myocardial ischaemia in at least a proportion of patients. Radionuclide myocardial perfusion defects, coronary sinus oxygen saturation abnormalities and pH changes, myocardial lactate production and stress-induced alterations of cardiac high energy phosphate have been reported in CSX patients, suggesting an ischaemic origin for their symptoms. Microvascular abnormalities often caused by endothelial dysfunction appear to be responsible for myocardial ischaemia in these patients. CSX is more prevalent in women than in men, and the majority of women with CSX are peri- or post-menopausal. Thus oestrogen deficiency has been suggested to have a pathogenic role in CSX. Additional factors such as abnormal pain perception may also contribute to the genesis of chest pain in patients with angina and normal coronary angiograms. The management of this syndrome is difficult because of the heterogeneity of pathogenic mechanisms and uncertainties as to its origin. This article discusses the problem of CSX in women, the potential pathogenic role of oestrogen deficiency, and practical clinical management.

The relationship between plasma BNP level and the myocardial phosphocreatine/adenosine triphosphate ratio determined by phosphorus-31 magnetic resonance spectroscopy in patients with dilated cardiomyopathy

The purpose of this study was to evaluate the correlation between the plasma B-type natriuretic peptide (BNP) level and the myocardial phosphocreatine/adenosine triphosphate ratio determined using rapid phosphorus-31 magnetic resonance spectroscopy (31P-MRS) in patients with dilated cardiomyopathy (DCM). Thirteen DCM patients, who had slight or moderate heart failure, were examined. The plasma BNP was measured on a day close to the rapid 31P-MRS study. 31P-MRS measurements were conducted with a 1.5-T MR instrument. The plasma BNP levels tended to be correlated negatively with the myocardial phosphocreatine/adenosine triphosphate, although the correlation did not reach statistical significance (r = -0.54, p = 0.06). By contrast, the log of the plasma BNP levels was correlated negatively with the myocardial phosphocreatine/adenosine triphosphate (r = -0.73, p < 0.01). Our results indicate that the myocardial energy metabolism evaluated using 31P-MRS tends to be correlated with the severity of heart failure and left ventricular dysfunction estimated using the plasma BNP levels in DCM patients. This paper provides additional information regarding the relationship between the BNP and myocardial energy metabolism in DCM patients.

Are retinal microvascular abnormalities associated with large artery endothelial dysfunction and intima-media thickness? The Hoorn Study

It has been hypothesized that microvascular dysfunction affects endothelial dysfunction of the large arteries, which may explain the relationship of microvascular disease with macrovascular disease. The aim of the present study was to investigate the relationship of retinal microvascular disorders with endothelium-dependent FMD (flow-mediated vasodilatation) and carotid IMT (intima-media thickness). A total of 256 participants, aged 60–85 years, 70 with normal glucose metabolism, 69 with impaired glucose metabolism and 109 with Type II diabetes, were included in this study. All participants were ophthalmologically examined, including funduscopy and two field 45° fundus photography, and were graded for retinal sclerotic vessel abnormalities and retinopathy. Retinal arteriolar and venular diameters were measured with a computer-assisted method. Brachial artery, endothelium-dependent FMD and carotid IMT were assessed ultrasonically as measurements of endothelial function and early atherosclerosis respectively. After adjustment for age, sex and glucose tolerance status, retinal vessel diameters, retinal sclerotic vessel abnormalities and retinopathy were not significantly associated with FMD. In contrast with other retinal microvascular abnormalities, retinal venular dilatation was associated with increased IMT [standardized β value (95% confidence interval), 0.14 (0.005–0.25)]. This association was attenuated and lost statistical significance after adjustment for cardiovascular risk factors, in particular after correction for fasting insulin. In the present study, retinal microvascular disorders are not independently associated with impaired FMD. In addition, retinal venular dilatation is associated with increased IMT, although non-significantly after multivariable adjustment for cardiovascular risk factors. Therefore our data provide evidence that retinal microvascular disease is of limited value in risk stratification for future cardiovascular events.

Mean platelet volume in the patients with cardiac syndrome X

BACKGROUND

Angina with normal coronary arteries, cardiac syndrome X, is a diagnosis of exclusion. The exact mechanism of this clinical syndrome remains unclear. Although the prognosis is as good as equal to that of normal population, symptoms related with the syndrome impair largely quality of life. Mean platelet volume showing the platelet size is an indicator of platelet function. Larger platelets are more active than smaller ones.

METHODS AND RESULTS

We designed a study, evaluated mean platelet volume of the patients with cardiac syndrome X (group A) and stable angina (group B) and investigated the relation between groups. Eighty patients with cardiac syndrome X with a mean age of 51.08 +/- 9.79 years and 67 patients with stable angina with a mean age of 55.16 +/- 11.96 years were studied. At the end of the study, mean platelet volume of group A was significantly higher than that of group B, 10.55 +/- 1.08 fl vs. 9.39 +/- 0.58 fl, respectively (P < 0.001).

CONCLUSION

Raised platelet size has been shown to be associated with adverse cardiac events. Mean platelet volume has increased in acute coronary syndromes and also in cardiac syndrome X in our study. Life style modification may optimize platelet size and improve symptoms in these patients.

Insights from the NHLBI-Sponsored Women's Ischemia Syndrome Evaluation (WISE) Study: Part I: gender differences in traditional and novel risk factors, symptom evaluation, and gender-optimized diagnostic strategies

Despite a dramatic decline in mortality over the past three decades, coronary heart disease is the leading cause of death and disability in the U.S. Importantly, recent advances in the field of cardiovascular medicine have not led to significant declines in case fatality rates for women when compared to the dramatic declines realized for men. The current review highlights gender-specific issues in ischemic heart disease presentation, evaluation, and outcomes with a special focus on the results published from the National Institutes of Health-National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study. We will present recent evidence on traditional and novel risk markers (e.g., high sensitivity C-reactive protein) as well as gender-specific differences in symptoms and diagnostic approaches. An overview of currently available diagnostic test evidence (including exercise electrocardiography and stress echocardiography and single-photon emission computed tomographic imaging) in symptomatic women will be presented as well as data using innovative imaging techniques such as magnetic resonance subendocardial perfusion, and spectroscopic imaging will also be discussed.

Women and cardiovascular heart disease: clinical implications from the Women's Ischemia Syndrome Evaluation (WISE) Study. Are we smarter?

Review of the trend in cardiovascular disease mortality for males and females clearly demonstrated that whereas the trend shows a decline in males this decline is not observed in females. Multiple important reports emerged from the initial phases of the Women's Ischemic Syndrome Evaluation (WISE) study that may have significant clinical implications for our approach to cardiovascular disease in women. The data derived from the WISE study certainly provided important information to our understanding of the approach to women with cardiovascular disease. The clinical presentation may be different, and a gender-oriented questionnaire may enhance our diagnosis. In a multivariable model, low hemoglobin was associated with significantly higher risk of adverse outcomes. The risk factor assessment and the risk factor profiles in women that are associated with coronary artery disease may be different. Based on the studies from the WISE study, metabolic syndrome is a leading and a major risk factor in women. Moreover, the data further support the concept that the mechanism of ischemia in women may be localized in the microvascular coronary arteries. Therefore, the diagnoses of coronary microvascular dysfunction or endothelial dysfunction should be considered in women with chest pain who do not have obstructive coronary artery disease. It may be advantageous to add such diagnostic tests when the conventional tests are nondiagnostic. A revised clinical approach to cardiovascular disease in women may be designed and tested based on these findings.

MRI of Myocardial Perfusion

An overwhelming number of myocardial perfusion studies are done by nuclear isotope imaging. Magnetic resonance imaging during the first pass of an injected, contrast bolus has some significant advantages for detection of blood flow deficits, namely higher spatial resolution, absence of ionizing radiation, and speed of the test. Previous clinical studies have demonstrated that excellent sensitivity and specificity can be achieved with MR myocardial perfusion imaging for detecting coronary artery disease, and assessment of patients with acute chest pain. Furthermore, an absolute quantification of myocardial blood flow is feasible, as was demonstrated by comparison of MR perfusion imaging, to measurements with isotope labeled microspheres in experimental models. An integrated assessment of perfusion, function, and viability, is thus feasible by MRI to answer important clinical challenges such as the identification of stunned or hibernating, but viable myocardium.

Women and Ischemic Heart Disease

The current review highlights gender-specific issues in ischemic heart disease (IHD) presentation, evaluation, and outcomes with a special focus on the results derived from the National Institutes of Health-National Heart, Lung, and Blood Institute-sponsored Women's Ischemia Syndrome Evaluation (WISE) study. New evidence on gender-based differences in vascular wall, atherosclerotic plaque deposition, pathophysiology, and innovative cardiovascular imaging techniques are reviewed. Critical areas of further inquiry needed to advance new gender-specific IHD understanding are detailed.

Cardiac syndrome X: a critical overview and future perspectives

The classic definition of cardiac syndrome X (CSX) seems inadequate both for clinical and research purposes and should be replaced with one aimed at including a sufficiently homogeneous group of patients with the common plausible pathophysiological mechanism of coronary microvascular dysfunction. More specifically, CSX should be defined as a form of stable effort angina, which, according to careful diagnostic investigation, can reasonably be attributed to abnormalities in the coronary microvascular circulation.

Are we 'WISE'r? Findings from the NHLBI-sponsored Women's Ischemia Syndrome Evaluation study

Recognition of cardiovascular disease as the leading healthcare threat to women continues to shape the prioritization of efforts to more effectively diagnose and treat heart disease in women. At its inception almost 8 years ago, the National Heart, Lung and Blood Institute in the USA sponsored the Women's Ischemia Syndrome Evaluation (WISE) study, aiming to optimize symptom evaluation and diagnostic testing for ischemic heart disease in women and to explore pathophysiologic mechanisms for symptoms and myocardial ischemia in the absence of epicardial coronary artery stenosis. The WISE study has investigated the spectrum of anginal symptoms, diagnostic strategies for micro- and macrovascular coronary disease, and the role of psychosocial variables and reproductive hormones in ischemic heart-disease presentation. One of the pivotal WISE findings sheds light on chest pain in the absence of significant obstructive epicardial luminal coronary stenosis, otherwise known as Cardiac Syndrome X. In the WISE study, using coronary vasomotor testing during angiography, investigators observed prevalent abnormalities in coronary flow reserve, suggestive of microvascular coronary dysfunction in relation to adverse morbidity and mortality among these women. Findings such as these from the WISE study have significantly added to the current management approach to heart disease in women.

Hyperdynamic Myocardial Response to Beta-Adrenergic Stimulation in Patients With Chest Pain and Normal Coronary Arteries

OBJECTIVES

The goal of this study was to test the hypothesis that an abnormal response to beta-adrenergic stimulation may play a role in the pathophysiology of chest pain in patients with normal coronary arteries.

BACKGROUND

The mechanism of angina-like (AL) chest pain in patients with angiographically normal coronary arteries remains controversial.

METHODS

Fifty-eight patients with AL pain and a normal coronary angiogram underwent dobutamine echocardiography (DE) to evaluate regional wall motion and intraventricular flow velocities (IFV). Control patients consisted of 22 matched patients free of angina and coronary artery disease. Abnormal IFV were defined as dagger-shaped Doppler spectrum > or =3 m/s.

RESULTS

Dobutamine-induced regional wall motion abnormalities did not develop in any of the patients. An IFV > or = 3 m/s was found in 28 patients (48%) with AL pain but in only 4 (18%) control patients (p < 0.05). In the subgroup of patients with AL pain and IFV > or =3 m/s, plasma renin concentration (PRC) was higher as compared with those with IFV <3 m/s (18 +/- 17 pg/ml vs. 9 +/- 6 pg/ml, p < 0.05). There were no differences in plasma ADR, NADR, or angiotensin-converting enzyme levels. Fourteen patients with angina and IFV > or =3 underwent control DE and blood sampling after 6 weeks treatment with 10 mg of bisoprolol. In these patients, a decrease in IFV (from 3.4 +/- 0.35 m/s to 2.46 +/- 0.64 m/s, p < 0.001) and a decrease in angina score (from 5.4 +/- 1.5 to 0.6 +/- 1.4, p < 0.001) were observed at follow-up.

CONCLUSIONS

The present data suggest that an exaggerated myocardial response to beta-adrenergic stimulation plays a role in the mechanisms of chest pain in some patients with normal coronary arteries.

Cardiac syndrome X

Cardiac syndrome X, the triad of angina pectoris, a positive exercise electrocardiogram for myocardial ischaemia and angiographically smooth coronary arteries, is frequently associated with debilitating symptomology, increased psychological morbidity and a poor quality of life. While various avenues of research have been undertaken, there are as yet no definitive conclusions regarding the exact pathogenesis of the condition. A number of physiological mechanisms have been explored, including the existence of underlying myocardial ischaemia, suggested endothelial dysfunction, abnormal pain perception, hormonal irregularities and insulin resistance, while the psychological impact of the condition has also been explored. Various treatment regimens have also been the subject of research with varying degrees of success. The heterogeneous nature of the patient population suggests that the mechanistic pathway may be multifactorial, while a comprehensive treatment regimen including both psychosocial and pharmacological interventions may offer the best outcome for patients with cardiac syndrome X.