Assessment of the exercise electrocardiogram in women versus men using tomographic myocardial perfusion imaging as the reference standard

Clinical implication of myocardial FDG uptake pattern in oncologic PET: retrospective comparison study with stress myocardial perfusion imaging as the reference standard

OBJECTIVE

The purpose of this study was to determine the clinical implication of the myocardial FDG uptake patterns by comparing with the results of stress myocardial perfusion imaging (MPI) as the reference standard.

METHODS

By reviewing the medical records, 86 pairs of stress MPI and FDG PET/CT of 84 patients who underwent stress MPI and oncologic FDG PET/CT in 1 month were included in this study. The patterns of the myocardial FDG uptake were classified into five patterns such as 'low', 'diffuse', 'basal ring', 'focal high', and 'focal defect on diffuse high'. MPI was evaluated using a 5-point scoring model ranging from 0 (normal uptake) to 4 (uptake absent) based on the 17-segment model. The summed stress score of 4 or higher was defined as 'abnormal MPI'. Factors predictive of abnormal MPI were analyzed using a log-rank multivariate test and p < 0.05 was set as significant.

RESULTS

Abnormal MPI was observed in only 16 of 36 (44%) patients with 'low' pattern, 10 of 23 (43%) patients with 'diffuse high' pattern, and 1 of 9 (11%) patients with 'basal ring' pattern, but in 8 of 9 (89%) patients with 'focal high' pattern, and 8 of 9 (89%) patients with 'focal defect on diffuse high' pattern. The log-rank multivariate test revealed that 'focal high' and 'focal defect on diffuse high' pattern were correlated with an abnormal MPI.

CONCLUSIONS

These results indicate that further cardiac work-up might be helpful in the patients with 'focal high' pattern or 'focal defect on diffuse high' pattern of myocardial FDG at oncologic PET. A prospective study should be needed to further support this conclusion.

Gender aspects on exercise-induced ECG changes in relation to scintigraphic evidence of myocardial ischaemia

BACKGROUND

This retrospective study aimed to determine the diagnostic performance of exercise-induced ST response in relation to findings by myocardial perfusion single photon emission computed tomography (MPS), with focus on gender differences, in patients with suspected or established stable ischemic heart disease.

METHODS

MPS findings of 1 021 patients (518 females) were related to the exercise-induced ST response alone (blinded and unblinded to gender) and ST response together with additional exercise stress test (EST) variables (exercise capacity, blood pressure and heart rate response).

RESULTS

Exercise-induced ischaemia by MPS was found in 9% of females and 23% of males. Diagnostic performance of exercise-induced ST response in relation to MPS findings in females versus males was: sensitivity = 48%,70%; specificity = 67%, 64%; PPV = 13%, 38%; NPV = 93%, 87%. Adding more EST variables to the ST response interpretation yielded in females vs males: sensitivity = 44%, 51%; specificity = 84%, 83%; PPV = 22%, 48% and NPV = 93%, 85%.

CONCLUSIONS

In patients who have performed EST in conjunction with MPS, there is a gender difference in the diagnostic performance of ST response at stress, with a significantly lower PPV in females compared to males. For both genders, specificity can be significantly improved, and a higher PPV can be obtained, while the sensitivity might be compromised by considering more EST variables, in addition to the ST response.

[Myocardial ischaemia detection in women]

Screening of myocardial ischemia refers to the use of one or more diagnostic tests for coronary heart disease with a dual objective of appropriateness and promptness. In women, as compared to men, the accuracy of the different tests is worse. Thus, to overcome this sex-related penalty, we must define a diagnosis strategy based on risk stratification, enabling the identification of patients requiring invasive investigations. This review discusses various non-invasive diagnostic tests focusing on a female-specific approach and defines the use of numerous diagnostic tests with respect to both risk stratification and symptoms.

Advances in understanding gender difference in cardiometabolic disease risk

Gender differences exist in cardiovascular or metabolic disease risk, beyond the protective effect of estrogens, mostly burdening the postmenopausal female. We aimed to review herein sex differences in pro-inflammatory states, the independence of inflammation from insulin resistance, differences in high-density lipoprotein dysfunction, in gene-environment interactions, and in the influence of current and former smoking on cardiometabolic risk. Sex differences in absorption of long-chain fatty acids are highlighted. Differences exist in the first manifestation of cardiovascular disease, men being more likely to develop coronary heart disease as a first event, compared to women who have cerebrovascular disease or heart failure as a first event. Autoimmune activation resulting from pro-inflammatory states, a fundamental mechanism for numerous chronic diseases in people prone to metabolic syndrome, is much more common in women, and these constitute major determinants. Therapeutic approaches to aspects related to sex difference are briefly reviewed.

Diagnosing and characterizing coronary artery disease in women: developments in noninvasive and invasive imaging techniques

Cardiovascular disease is the leading cause of death in men and women in the USA; yet, coronary artery disease (CAD) continues to be underrecognized and underdiagnosed in women. Noninvasive and invasive imaging techniques are constantly being developed in order to more accurately assess CAD. At the same time, the impact of gender on the interpretation and accuracy of these studies is still being elucidated. Furthermore, new imaging techniques have improved our understanding of CAD pathophysiology and progression and have begun to reveal gender differences in the development of CAD. This article will review current imaging techniques and their application to diagnosing and understanding CAD in women.

A gender-specific blood-based gene expression score for assessing obstructive coronary artery disease in nondiabetic patients: results of the Personalized Risk Evaluation and Diagnosis in the Coronary Tree (PREDICT) trial

BACKGROUND

Currently available noninvasive tests to risk stratify patients for obstructive coronary disease result in many unnecessary cardiac catheterizations, especially in women. We sought to compare the diagnostic accuracy of presenting symptoms, noninvasive test results, and a gene expression score (GES) in identifying obstructive coronary artery disease (CAD) according to gender, using quantitative coronary angiography as the criterion standard.

METHODS

The PREDICT trial is a prospective multicenter observational study designed to develop and validate gene expression algorithms to assess obstructive CAD, defined as at least one ≥50% diameter stenosis measured by quantitative coronary angiography. Patients referred for diagnostic cardiac catheterization with suspected but previously unknown CAD were enrolled. Noninvasive myocardial perfusion imaging (MPI) was available in 60% of patients. The GES, comprising gender-specific age functions and 6 gene expression terms containing 23 genes, was performed for all patients.

RESULTS

A total of 1,160 consecutive patients (57.6% men and 42.4% women) were enrolled in PREDICT. The prevalence of obstructive CAD was 46.7% in men and 22.0% in women. Chest pain symptoms were a discriminator of obstructive CAD in men (P < .001) but not in women. The positive predictive value of MPI was significantly higher in men (45%) than in women (22%). An abnormal site-read MPI was not significantly associated with obstructive or severity of CAD. The GES was significantly associated with a 2-fold increase in the odds of obstructive CAD for every 10-point increment in the GES and had a significant association with all measures of severity and burden of CAD. By multivariable analysis, GES was an independent predictor of obstructive CAD in the overall population (odds ratio [OR] 2.53, P = .001) and in the male (OR 1.99, P = .001) and female (OR 3.45, P = .001) subgroups separately, whereas MPI was not.

CONCLUSIONS

Commonly used diagnostic approaches including symptom evaluation and MPI performed less well in women than in men for identifying significant CAD. In contrast, gender-specific GES performed similarly in women and men. Gene expression score offers a reliable diagnostic approach for the assessment of nondiabetic patients and, in particular, women with suspected obstructive CAD.

Diagnostic accuracy of exercise stress testing for coronary artery disease: a systematic review and meta-analysis of prospective studies

BACKGROUND

Exercise stress testing offers a non-invasive, less expensive way of risk stratification prior to coronary angiography, and a negative stress test may actually avoid angiography. However, previous meta-analyses have not included all exercise test modalities, or patients without known Coronary artery disease (CAD).

METHODS AND RESULTS

We systematically reviewed the literature to determine the diagnostic accuracy of exercise stress testing for CAD on angiography. MEDLINE (January 1966 to November 2009), MEDION (1966 to July 2009), CENTRAL (1966 to July 2009) and EMBASE (1980-2009) databases were searched for English language articles on diagnostic accuracy of exercise stress testing. We included prospective studies comparing exercise stress testing with a reference standard of coronary angiography in patients without known CAD. From 6,055 records, we included 34 studies with 3,352 participants. Overall, we found published studies regarding five different exercise testing modalities: treadmill ECG, treadmill echo, bicycle ECG, bicycle echo and myocardial perfusion imaging. The prevalence of CAD ranged from 12% to 83%. Positive and negative likelihood ratios of stress testing increased in low prevalence settings. Treadmill echo testing (LR+ = 7.94) performed better than treadmill ECG testing (LR+ = 3.57) for ruling in CAD and ruling out CAD (echo LR- = 0.19 vs. ECG LR- = 0.38). Bicycle echo testing (LR+ = 11.34) performed better than treadmill echo testing (LR+ = 7.94), which outperformed both treadmill ECG and bicycle ECG. A positive exercise test is more helpful in younger patients (LR+ = 4.74) than in older patients (LR+ = 2.8).

CONCLUSIONS

The diagnostic accuracy of exercise testing varies, depending upon the age, gender and clinical characteristics of the patient, prevalence of CAD and modality of test used. Exercise testing, whether by echocardiography or ECG, is more useful at excluding CAD than confirming it. Clinicians have concentrated on individualising the treatment of CAD, but there is great scope for individualising the diagnosis of CAD using exercise testing.

Use of electrocardiographic depolarization abnormalities for detection of stress-induced ischemia as defined by myocardial perfusion imaging

High-frequency mid-QRS (HFQRS) analysis was recently introduced as a tool for identification of stress-induced ischemia. The diagnostic performance of this electrocardiographic technique has not been determined in a large cohort of patients. This study compared the diagnostic performance of HFQRS analysis to conventional ST-segment analysis in detecting exercise-induced ischemia. The study included 996 patients (56 ± 10 years of age, 670 men) referred for exercise myocardial perfusion imaging (MPI), which served as the gold standard of ischemia. High-resolution electrocardiogram was used for computer analysis of HFQRS signals. Number of electrocardiographic leads with ≥50% decrease of HFQRS intensity (L(50%)) was used as an index of ischemia. Perfusion images were evaluated semiquantitatively. Receiver operating characteristic analysis demonstrated an L(50%) ≥3 as the criterion that yielded optimal sensitivity and specificity for diagnosing moderate/severe ischemia. Compared to ST-segment analysis HFQRS analysis was more sensitive (69% vs 39%, p <0.005) and more specific (86% vs 82%, p <0.05). L(50%) correlated with amount of MPI ischemia (R(2) = 0.75, p <0.0001). Multivariate logistic regression analysis demonstrated a significant incremental diagnostic value for the addition of HFQRS data to a model containing pretest and conventional exercise parameters. L(50%) was the best predictor of mild or moderate/severe MPI ischemia. In conclusion, computerized HFQRS analysis improved the diagnostic performance of conventional stress electrocardiogram in detecting exercise-induced ischemia. Thus, this technique might aid in the noninvasive evaluation of coronary artery disease.

Women & heart disease: symptoms and treatment guidelines

Coronary heart disease is the leading cause of death for women. Many women and some NPs are not aware of women's risk of myocardial infarction (MI) or that women's MI symptoms often differ from men's. NPs need to educate women about their risk and follow practice guidelines.

The accuracy of the electrocardiogram during exercise stress test based on heart size

BACKGROUND

Multiple studies have shown that the exercise electrocardiogram (ECG) is less accurate for predicting ischemia, especially in women, and there is additional evidence to suggest that heart size may affect its diagnostic accuracy.

HYPOTHESIS

The purpose of this investigation was to assess the diagnostic accuracy of the exercise ECG based on heart size.

METHODS

We evaluated 1,011 consecutive patients who were referred for an exercise nuclear stress test. Patients were divided into two groups: small heart size defined as left ventricular end diastolic volume (LVEDV) <65 mL (Group A) and normal heart size defined as LVEDV ≥65 mL (Group B) and associations between ECG outcome (false positive vs. no false positive) and heart size (small vs. normal) were analyzed using the Chi square test for independence, with a Yates continuity correction. LVEDV calculations were performed via a computer-processing algorithm. SPECT myocardial perfusion imaging was used as the gold standard for the presence of coronary artery disease (CAD).

RESULTS

Small heart size was found in 142 patients, 123 female and 19 male patients. There was a significant association between ECG outcome and heart size (χ(2) = 4.7, p = 0.03), where smaller hearts were associated with a significantly greater number of false positives.

CONCLUSIONS

This study suggests a possible explanation for the poor diagnostic accuracy of exercise stress testing, especially in women, as the overwhelming majority of patients with small heart size were women.

Lack of correlation between noninvasive stress tests and invasive coronary vasomotor dysfunction in patients with nonobstructive coronary artery disease

BACKGROUND

Despite a nonobstructive coronary angiogram, many patients may still have an abnormal coronary vasomotor response to provocation and to myocardial demand during stress. The ability of noninvasive stress tests to predict coronary vasomotor dysfunction in patients with nonobstructive coronary artery disease is unknown.

METHODS AND RESULTS

All patients with nonobstructive coronary artery disease who had invasive coronary vasomotor assessment and a noninvasive stress test (exercise ECG, stress echocardiography, or stress nuclear imaging) within 6 months of the cardiac catheterization with provocation at our institution were identified (n=376). Coronary vasomotor dysfunction was defined as a percentage increase in coronary blood flow of <or=50% to intracoronary acetylcholine (endothelium-dependent dysfunction) and/or a coronary flow reserve ratio of <or=2.5 to intracoronary adenosine (endothelium-independent dysfunction). We determined the sensitivity and specificity of various noninvasive stress tests to predict coronary vasomotor dysfunction in these patients. On invasive testing, 233 patients (63%) had coronary vasomotor dysfunction, of which 187 patients (51%) had endothelium-dependent dysfunction, 109 patients (29%) had endothelium-independent dysfunction, and 63 patients (17%) had both. On noninvasive stress testing, 157 (42%) had a positive imaging study and 56 (15%) a positive ECG stress test. The noninvasive stress tests had limited diagnostic accuracy for predicting coronary vasomotor dysfunction (41% sensitivity [95% CI, 34 to 47] and 57% specificity [95% CI, 49 to 66]), endothelium-dependent dysfunction (41% sensitivity [95% CI, 34 to 49] and 58% specificity [95% CI, 50 to 65]), or endothelium-independent dysfunction (46% sensitivity [95% CI, 37 to 56] and 61% specificity [95% CI, 54 to 67]). The exercise ECG test was more specific but less sensitive than the imaging tests.

CONCLUSIONS

This study suggests that a negative noninvasive stress test does not rule out coronary vasomotor dysfunction in symptomatic patients with nonobstructive coronary artery disease. This underscores the need for invasive assessment or novel more sensitive noninvasive imaging for these patients.

The Prognostic Value of Normal Exercise Myocardial Perfusion Imaging and Exercise Echocardiography

OBJECTIVES

The purpose of this work was to determine the prognostic value of normal exercise myocardial perfusion imaging (MPI) tests and exercise echocardiography tests, and to determine the prognostic value of these imaging modalities in women and men.

BACKGROUND

Exercise MPI and exercise echocardiography provide prognostic information that is useful in the risk stratification of patients with suspected coronary artery disease (CAD).

METHODS

We searched the PubMed, Cochrane, and DARE databases between January 1990 and May 2005, and reviewed bibliographies of articles obtained. We included prospective cohort studies of subjects who underwent exercise MPI or exercise echocardiography for known or suspected CAD, and provided data on primary outcomes of myocardial infarction (MI) and cardiac death with at least 3 months of follow-up. Secondary outcomes (unstable angina, revascularization procedures) were abstracted if provided. Studies performed exclusively in patients with CAD were excluded.

RESULTS

The negative predictive value (NPV) for MI and cardiac death was 98.8% (95% confidence interval [CI] 98.5 to 99.0) over 36 months of follow-up for MPI, and 98.4% (95% CI 97.9 to 98.9) over 33 months for echocardiography. The corresponding annualized event rates were 0.45% per year for MPI and 0.54% per year for echocardiography. In subgroup analyses, annualized event rates were <1% for each MPI isotope, and were similar for women and men. For secondary events, MPI and echocardiography had annualized event rates of 1.25% and 0.95%, respectively.

CONCLUSIONS

Both exercise MPI and exercise echocardiography have high NPVs for primary and secondary cardiac events. The prognostic utility of both modalities is similar for both men and women.

Cardiovascular diseases in women: a statement from the policy conference of the European Society of Cardiology

Cardiovascular diseases (CVD) are the leading cause of mortality both in men and women. In Europe, about 55% of all females' deaths are caused by CVD, especially coronary heart disease and stroke. Unfortunately, however, the risk of heart disease in women is underestimated because of the perception that women are 'protected' against ischaemic heart disease. What is not fully understood is that women during the fertile age have a lower risk of cardiac events, but this protection fades after menopause thus leaving women with untreated risk factors vulnerable to develop myocardial infarction, heart failure, and sudden cardiac death. Furthermore, clinical manifestations of ischaemic heart disease in women may be different from those commonly observed in males and this factor may account for under-recognition of the disease. The European Society of Cardiology has recently initiated an extensive 'Women at heart' program to coordinate research and educational initiatives on CVD in women. A Policy Conference on CVD in Women was one of the first steps in the development of this program. The objective of the conference was to collect the opinion of experts in the field coming from the European Society of Cardiology member countries to: (1) summarize the state-of-the-art from an European perspective; (2) to identify the scientific gaps on CVD in women; and (3) to delineate the strategies for changing the misperception of CVD in women, improving risk stratification, diagnosis, and therapy from a gender perspective and increasing women representation in clinical trials. The Policy Conference has provided the opportunity to review and comment on the current status of knowledge on CVD in women and to prioritize the actions needed to advance this area of knowledge in cardiology. In the preparation of this document we intend to provide the medical community and the stakeholders of this field with an overview of the more critical aspects that have emerged during the discussion. We also propose some immediate actions that should be undertaken with the hope that synergic activities will be implemented at European level with the support of national health care authorities.

[Myocardial perfusion scintigraphy in type 2 diabetic patients with atypical chest pain]

To verify the prevalence of ischemic myocardial abnormalities, 67 patients with type 2 diabetes mellitus (DM2) with normal basal electrocardiogram (EKG) or with ventricular repolarization abnormalities were evaluated by a perfusional myocardial scintigraphy. The average age was 63.5 +/- 9 years. Twenty-one (31.3%) were male and 46 (68.7%) female. A significant part of the sample (62.7%) had a normal myocardial scan, 37.3% were positive for ischemia. The majority of the sample (91%; n = 61) was submitted to an EKG during exercise which was positive for ischemia in 31.1%. The concordance between myocardial scintigraphy and the EKG during exercise demonstrated a low correlation between the two procedures (Kappa = 0.49; P = 0.0001). We conclude that perfusional myocardial scan is a highly valuable tool for evaluation and diagnosis of coronary artery disease in DM2 patients with atypical angina.