Development and validation of a simple exercise test score for use in women with symptoms of suspected coronary artery disease

Unsettled Issues and Future Directions for Research on Cardiovascular Diseases in Women

Biological sex (being female or male) significantly influences the course of disease. This simple fact must be considered in all cardiovascular diagnosis and therapy. However, major gaps in knowledge about and awareness of cardiovascular disease in women still impede the implementation of sex-specific strategies. Among the gaps are a lack of understanding of the pathophysiology of women-biased coronary artery disease syndromes (spasms, dissections, Takotsubo syndrome), sex differences in cardiomyopathies and heart failure, a higher prevalence of cardiomyopathies with sarcomeric mutations in men, a higher prevalence of heart failure with preserved ejection fraction in women, and sex-specific disease mechanisms, as well as sex differences in sudden cardiac arrest and long QT syndrome. Basic research strategies must do more to include female-specific aspects of disease such as the genetic imbalance of 2 versus one X chromosome and the effects of sex hormones. Drug therapy in women also needs more attention. Furthermore, pregnancy-associated cardiovascular disease must be considered a potential risk factor in women, including pregnancy-related coronary artery dissection, preeclampsia, and peripartum cardiomyopathy. Finally, the sociocultural dimension of gender should be included in research efforts. The organization of gender medicine must be established as a cross-sectional discipline but also as a centered structure with its own research resources, methods, and questions.

Optimising diagnostic accuracy with the exercise ECG: opportunities for women and men with stable ischaemic heart disease

The exercise ECG is an integral part within the evaluation algorithm for diagnosis and risk stratification of patients with stable ischaemic heart disease (SIHD). There is evidence, both older and new, that the exercise ECG can be an effective and cost-efficient option for patients capable of performing at maximal levels of exercise with suitable resting ECG findings. In this review, we will highlight the major dilemmas in interpreting suspected coronary artery disease symptoms in women and identify optimal strategies for employing exercise ECG as a first-line diagnostic test in the SIHD evaluation algorithm. We will highlight current evidence as well as recent guideline statements on this subject.

TRIAL REGISTRATION NUMBER

NCT01471522; Pre-results.

Gender differences in the prognostic value of exercise treadmill test characteristics

BACKGROUND

Although exercise treadmill testing (ETT) is less sensitive and specific for diagnosis of coronary disease in women, little is known about gender differences in the prognostic importance of ETT variables.

METHODS

We studied 9,569 consecutive patients (46.8% women) referred for ETT between July 2001 and June 2004 in a community-based system. We assessed the association between ETT variables (exercise capacity, symptoms, ST-segment deviations, heart rate recovery, and chronotropic response) and time to all-cause death and myocardial infarction (MI), adjusting for patient and stress test characteristics. Models were stratified by gender to determine the relationship between ETT variables and outcomes.

RESULTS

In the entire population, exercise capacity and heart rate recovery were significantly associated with all-cause death, whereas exercise capacity, chest pain, and ST-segment deviations were significantly associated with subsequent MI. The relationship between ETT variables and outcomes were similar between men and women, except for abnormal exercise capacity, which had a significantly stronger association with death in men (men: hazard ratio [HR] 2.89 and 95% CI 1.89-4.44, women: HR 0.99 and 95% CI 0.52-1.93, and interaction P = .01), and chronotropic incompetence, which had a significantly stronger relationship with MI in women (men: HR 1.29 and 95% CI 0.74-2.20, women: HR 2.79 and 95% CI 0.94-8.27, and interaction P = .04).

CONCLUSIONS

Although many traditional ETT variables had similar prognostic value in both men and women, exercise capacity was more prognostically important in men, and chronotropic incompetence was more important in women. Future studies should confirm these findings in additional populations.

Noncardiac chest pain in the emergency department: the role of cardiac history, anxiety or depression and Type D personality

BACKGROUND

Noncardiac chest pain is common in patients presenting to emergency departments and is frequently associated with panic disorder. This can represent a major burden for patients and the healthcare system. Little is known about the patient characteristics that increase the risk of noncardiac chest pain. We examined whether cardiac history or Type D personality was associated with panic disorder and/or depression-driven noncardiac chest pain.

METHODS AND RESULTS

Patients presenting with noncardiac chest pain to the emergency department of the University Hospital Maastricht were screened using the Hospital Anxiety and Depression Scale (HADS). Patients scoring > or =8 on the HADS subscale were invited for a psychiatric interview; a consecutive sample of patients scoring <8 on the HADS was included as a reference group. Type D personality (tendency to experience emotional distress) was assessed with the DS14. Among the 304 HADS-positive patients, 89% were diagnosed with panic disorder/depression as compared with 8% of the 106 HADS-negative patients. Previous cardiac history was not associated with psychiatric diagnosis. Type D patients reported more anxiety symptoms (12.4+/-4.0 vs. 8.1+/-4.9) and depression symptoms on the HADS (10.2+/-4.7 vs. 5.8+/-4.9) and more often had comorbid panic disorder/depression (91/157=58% vs. 57/253=23%) than non-Type D patients (P<0.0001). Type D personality (odds ratio =8.67, 95% confidence interval 4.69-16.02), younger age and male sex were independently associated with increased risk of panic disorder or depression. Type D was independently associated with comorbid panic disorder/depression (odds ratio=14.49).

CONCLUSION

Type D personality, but not cardiac history, is independently associated with the presence of psychopathology in noncardiac chest pain. Type D is associated with a substantially increased risk of co-occurring PD/depression in these patients.

Development and validation of a derived measure of research utilization by nurses

BACKGROUND

Theoretical models are needed to guide strategies for the implementation of research into clinical practice. To develop and test such models, including analyses of complex theoretical constructs and causal relationships, rich datasets are needed. Working with existing datasets may mean that important variables are lacking.

OBJECTIVE

The aim of this study was to derive a nursing research utilization variable and validate it using the Promoting Action on Research Implementation in Health Services (PARIHS) conceptual framework on research implementation.

METHODS

This study was based on data from two surveys of registered nurses. The first survey (1996; N = 600) contained robust research utilization variables but few organizational variables. The second (1998; N = 6,526) was rich in organizational variables but contained no research utilization variables. A linear regression model with predictors common to both datasets was used to derive a research utilization variable in the 1998 dataset. To validate these scores, four separate procedures based on the hypothesis of a positive relationship between context and research utilization were completed. Mutually exclusive groups reflecting various levels of context were created to accomplish these procedures.

RESULTS

The derived research utilization variable was successfully mapped onto the cases in the 1998 dataset. The derived scores ranged from 0.21 to 21.40, with a mean of 10.85 (SD = 3.23). The mean score per subgroup ranged from 8.28 for the lowest context group to 12.75 for the highest context group. One of the validation procedures showed that significant differences in mean research utilization existed only among four conceptually unique context groups (p < .001). These groups showed a positive incremental relationship in research utilization (p < .001; the better the context, the higher the research utilization score). The validity of the derived variable was supported by using the three remaining validation procedures.

DISCUSSION

The successful creation and validation of a derived research utilization variable will enable advanced modeling of the relationships between research utilization and individual and organizational characteristics. The findings also support the construct validity of the context element of the PARIHS theoretical framework.

Gender differences in the management and clinical outcome of stable angina

BACKGROUND

We sought to examine the impact of gender on the investigation and subsequent management of stable angina and to assess gender differences in clinical outcome at 1 year.

METHODS AND RESULTS

The Euro Heart Survey of Stable Angina enrolled patients with a clinical diagnosis of stable angina on initial assessment by a cardiologist. Baseline clinical details and cardiac investigations planned or performed within a 4-week period of the assessment were recorded, and follow-up data were collected at 1 year. A total of 3779 patients were included in the survey; 42% were female. Women were less likely to undergo an exercise ECG (odds ratio, 0.81; 95% CI, 0.69 to 0.95) and less likely to be referred for coronary angiography (odds ratio, 0.59; 95% CI, 0.48 to 0.72). Antiplatelet and statin therapies were used significantly less in women than in men, both at initial assessment and at 1 year, even in those in whom coronary disease had been confirmed. Women with confirmed coronary disease were less likely to be revascularized than their male counterparts and were twice as likely to suffer death or nonfatal myocardial infarction during the 1-year follow-up period (hazard ratio, 2.09; 95% CI, 1.13 to 3.85), even after multivariable adjustment for age, abnormal ventricular function, severity of coronary disease, and diabetes.

CONCLUSIONS

Significant gender bias has been identified in the use of investigations and evidence-based medical therapy in stable angina. Women were also less likely to be revascularized. The observed bias is of particular concern in light of the adverse prognosis observed among women with stable angina and confirmed coronary disease.

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.

Assessment of estrogen status as a marker of prognosis in women with symptoms of suspected coronary artery disease presenting for stress testing

Estrogen status (ES) has previously been shown to be a marker of angiographic outcome in women. In light of this finding, a reevaluation of ES as a marker of prognosis was undertaken. Two thousand one hundred forty-three women who underwent stress testing for symptoms of suspected coronary disease were studied. ES was defined according to menopausal, ovarian, and hormone replacement therapy status. The end points of interest were all-cause mortality, cardiac death, and nonfatal myocardial infarction. Survival analysis was performed using the Kaplan-Meier method and Cox regression analysis with censoring at revascularization. Compared with 1,362 ES-positive women, the 781 ES-negative women had a higher frequency of unfavorable end points (all-cause death: ES positive 31 [2.3%] vs ES negative 94 [12%], p < 0.0001, cardiac death: ES positive 11 [0.8%] vs ES negative 38 [4.9%], p < 0.0001, and nonfatal myocardial infarction: ES positive 11 [0.8%] vs ES negative 17 [2.2%], p = 0.007). The Kaplan-Meier curve analysis indicated that ES was a marker of cardiac risk (p < 0.0001) in all women, as well as in postmenopausal women. Multivariate Cox regression analysis revealed that ES was an independent marker of risk (p < 0.001) when considered with other standard risk factors. Using logistic regression and area under the curve analyses, ES had incremental value compared with standard risk factors. In conclusion, ES appears to be an easily discernible independent marker of risk that provides incremental prognostic information compared with standard clinical variables in women with symptoms of suspected coronary disease presenting for stress testing.

Validation of the accuracy of pretest and exercise test scores in women with a low prevalence of coronary disease: the NHLBI-sponsored Women's Ischemia Syndrome Evaluation (WISE) study

BACKGROUND

Recently revised American College of Cardiology/American Heart Association guidelines have suggested that exercise test scores be used in decisions concerning patients with suspected coronary artery disease (CAD). Pretest and exercise test scores derived for use in women without known CAD have not been tested in women with a low prevalence of CAD.

METHODS

Within the Women's Ischemia Syndrome Evaluation (WISE) study, we evaluated 563 women undergoing coronary angiography for suspected myocardial ischemia. The prevalence of angiographic CAD was 26%. Overall, 189 women underwent treadmill exercise testing. Prognostic end points included death, myocardial infarction, stroke, and revascularization.

RESULTS

Each score stratified women into 3 probability groups (P <.001) according to the prevalence of coronary disease: Pretest: low 20/164 (12%), intermediate 53/245 (22%), high 75/154 (49%); Exercise test: low 11/83 (13%), intermediate 22/74 (30%), high 17/32 (53%). However, the Duke score did not stratify as well: low 7/46 (15%), intermediate 36/126 (29%), high 6/17 (35%); P =.44. When pretest and exercise scores were considered together, the best stratification with the exercise test score was in the intermediate pretest group (P <.03). The Duke score did not stratify this group at all (P =.98). Pretest and exercise test scores also stratified women according to prognostic end points: pretest--low 7/164 (4.3%), intermediate 28/245 (11.4%), high 27/154 (17.5%), P <.01; exercise test--low 4/83 (4.8%) and intermediate-high 17/106 (16%), P =.014.

CONCLUSION

Both pretest and exercise test scores performed better than the Duke score in stratifying women with a low prevalence of angiographic CAD. The exercise test score appears useful in women with an intermediate pretest score, consistent with American College of Cardiology/American Heart Association guidelines.

Improving the positive predictive value of exercise testing in women

OBJECTIVE

To identify exercise test variables that can improve the positive predictive value of exercise testing in women.

DESIGN

Cohort study.

SETTING

Regional cardiothoracic centre.

SUBJECTS

1286 women and 1801 men referred by primary care physicians to a rapid access chest pain clinic, of whom 160 women and 406 men had ST depression of at least 1 mm during exercise testing. The results for 136 women and 124 men with positive exercise tests were analysed.

MAIN OUTCOME MEASURES

The proportion of women with a positive exercise test who could be identified as being at low risk for prognostic coronary heart disease and the resulting improvement in the positive predictive value.

RESULTS

Independently of age, an exercise time of more than six minutes, a maximum heart rate of more than 150 beats/min, and an ST recovery time of less than one minute were the variables that best identified women at low risk. One to three of these variables identified between 11.8% and 41.2% of women as being at low risk, with a risk for prognostic disease of between 0-11.5%. The positive predictive value for the remaining women was improved from 47.8% up to 61.5%, and the number of normal angiograms was potentially reducible by between 21.1-54.9%. By the same criteria, men had higher risks for prognostic disease.

CONCLUSIONS

A strategy of discriminating true from false positive exercise tests is worthwhile in women but less successful in men.

Evaluation of pretest and exercise test scores to assess all-cause mortality in unselected patients presenting for exercise testing with symptoms of suspected coronary artery disease

OBJECTIVES

To determine how well recently developed multivariables scores assess for all-cause mortality in patients with suspected coronary disease presenting for exercise electrocardiography (ExECG).

BACKGROUND

Recently revised American College of Cardiology/American Heart Association guidelines for ExECG have suggested that ExECG scores be used to assist in management decisions in patients with suspected coronary artery disease. Recently developed scores accurately stratify patients according to angiographic disease severity.

METHODS

To determine how well these scores assess for all-cause mortality, we utilized 4,640 patients without known coronary disease who underwent ExECG to evaluate symptoms of suspected coronary disease between 1995 and 2001. Previously validated pretest and exercise test scores as well as the Duke treadmill score were applied to each patient. All-cause mortality was our end point.

RESULTS

Overall mortality was 3.0% with 2.8 +/- 1.6 years of follow-up. All three scores stratified patients into low-, intermediate-, and high-risk groups (p < 0.00001). No differences were seen when patients were evaluated as subgroups according to gender, diabetes, beta-blockers, or inpatient status. Low-risk patients defined by the Duke treadmill score had consistently higher mortality and absolute number of deaths compared with low-risk patients using other scores. In addition, the Duke treadmill score had less incremental stratifying value than the new exercise score.

CONCLUSIONS

Simple pretest and exercise scores risk-stratified patients with suspected coronary disease in accordance with published guidelines and better than the Duke treadmill score. These results extend to diabetics, inpatients, women, and patients on beta-blockers.