Recruitment Strategies and Costs Associated With Enrolling People With Insomnia and High Blood Pressure Into an Online Behavioral Sleep Intervention: A Single-Site Pilot Study.

BACKGROUND: Recruitment in clinical research is a common challenge and source of study failure. The reporting of recruitment methods and costs in hypertension trials is limited especially for smaller, single-site trials, online intervention trials, and trials using newer online recruitment strategies. OBJECTIVE: The aims of this study are to describe and examine the feasibility of newer online-e-mail recruitment strategies and traditional recruitment strategies used to enroll participants with insomnia and high blood pressure into an online behavioral sleep intervention study (Sleeping for Heart Health). METHODS: The 16 online-e-mail-based and traditional recruitment strategies used are described. Recruitment strategy feasibility was examined by study interest and enrollee yields, conversion rates, and costs (direct, remuneration, labor, and cost per enrollee). RESULTS: From August 2014 to October 2015, 183 people were screened and 58 (31.7%) enrolled in the study (51.1 ± 12.9 years, 63.8% female, 72.4% African American, 136 ± 12/88 ± 7 mm Hg, 87.9% self-reported hypertension, 67.2% self-reported antihypertensive medication use). The recruitment strategies yielding the highest enrollees were the university hospital phone waiting message system (25.4%), Craigslist (22.4%), and flyers (20.3%) at a per enrollee cost of $42.84, $98.90, and $128.27, respectively. The university hospital phone waiting message system (55.6%) and flyers (54.5%) had the highest interested participant to enrolled participant conversion rate of all recruitment strategies. CONCLUSION: Approximately 70% of all enrolled participants were recruited from the university hospital phone waiting message system, Craigslist, or flyers. Given the recruitment challenges that most researchers face, we encourage the documenting, assessing, and reporting of detailed recruitment strategies and associated recruitment costs so that other researchers may benefit.

Insomnia Symptoms Are Associated With Abnormal Endothelial Function.

BACKGROUND: Insomnia is a prevalent sleep disorder, and it has been increasingly associated with cardiovascular morbidity and mortality. The reasons for this relationship are not completely understood but may involve endothelial dysfunction. In this study, we hypothesized that insomnia symptoms would be associated with reduced endothelial function. METHODS: Working adults (n = 496, 67.5% female, 78.6% white, mean age 48.7 [SD, 10.8] years, body mass index 28.2 [SD, 6.7] kg/m, diabetes 5.8%, hypertension 20.0%, hyperlipidemia 17.9%, heart disease 2.6%) enrolled in the Emory-Georgia Tech Predictive Health Institute study completed baseline demographic, clinical, depression (Beck Depression Inventory II), anxiety (General Anxiety Disorder 7), sleep (Pittsburg Sleep Quality Index), and noninvasive endothelial function (brachial artery flow-mediated dilation [FMD]) measures. Insomnia symptoms were defined as subjective sleep latency of 30 minutes or longer, nighttime or early morning awakenings, and/or sleep medication use occurring 3 times or more per week in the past month. RESULTS: Insomnia symptoms were reported by 39.5% of participants. Multivariable regression models showed that insomnia symptoms, age, baseline artery diameter, and dyslipidemia were inversely related to FMD. After adjusting for age, baseline artery diameter, and dyslipidemia, participants reporting insomnia symptoms had lower FMD than did participants reporting better sleep (adjusted FMD mean, 6.13% [SD, 0.28%] vs 6.83% [SD, 0.26%], P = .035). CONCLUSION: In this study, insomnia symptoms were associated with reduced FMD. Research examining the therapeutic benefits of treating insomnia on endothelial function and future cardiovascular risk is warranted.

High trait rumination is associated with blunted nighttime diastolic blood pressure dipping.

BACKGROUND: Blunted blood pressure (BP) dipping during nighttime sleep has been associated with an increased risk of cardiovascular events. Psychological traits have been associated with prolonged cardiovascular activation and a lack of cardiovascular recovery. This activation may extend into nighttime sleep and reduce BP dipping. PURPOSE: This study aims to evaluate the association between trait rumination and nighttime BP dipping. METHODS: Sixty women scoring either high or low on trait rumination underwent one 24-h ambulatory BP monitoring session. Self-reported wake and sleep times were used to calculate nighttime BP. RESULTS: High trait rumination was associated with less diastolic blood pressure (DBP) dipping relative to low trait rumination. Awake ambulatory BP, asleep systolic blood pressure (SBP) and DBP, and asleep SBP dipping were not associated with trait rumination. CONCLUSIONS: In a sample of young women, high trait rumination was associated with less DBP dipping, suggesting that it may be associated with prolonged cardiovascular activation that extends into nighttime sleep, blunting BP dipping.

Coping effectively with heart failure (COPE-HF): design and rationale of a telephone-based coping skills intervention.

BACKGROUND: Coping Effectively with Heart Failure (COPE-HF) is an ongoing randomized clinical trial funded by the National Institutes of Health to evaluate if a coping skills training (CST) intervention will result in improved health status and quality of life as well as reduced mortality and hospitalizations compared with a heart failure education (HFE) intervention. METHODS AND RESULTS: Two hundred heart failure (HF) patients recruited from the Duke University Medical Center and the University of North Carolina Hospital system will be randomized to a CST intervention (16 weekly 30-minute telephone counseling sessions including motivational interviewing and individually tailored cognitive behavioral therapy) or to an HFE intervention (16 weekly 30-minute telephone sessions including education and symptom monitoring). Primary outcomes will include postintervention effects on HF biomarkers (B-type natriuretic peptide, ejection fraction) and quality of life, as well as long-term clinical outcomes (hospitalizations and death). Secondary analyses will include an evaluation of treatment effects across subpopulations, and potential mechanisms by which CST may improve clinical outcomes. CONCLUSIONS: COPE-HF is a proof-of-concept study that should provide important insights into the health benefits of a CST intervention designed to enhance HF self-management, improve health behaviors, and reduce psychologic distress.

Hemodynamic response to postural shift in women with multiple chemical sensitivities.

Multiple chemical sensitivity (MCS) is a chronic condition prevalent in women; the symptoms are reproducible with repeated low-level chemical exposure. Evidence gathered through clinical observations suggests that women with MCS may be at risk for autonomic nervous system dysfunction as evidenced by abnormal heart rate and pulse pressure responses to exercise. The primary objective of this study was to describe the hemodynamic response to postural shift in 17 women with MCS. Using impedance cardiography, hemodynamic measures were taken while sitting and immediately upon standing. The hemodynamic response to standing was increased heart rate (p < .0001), decreased stroke volume (p = .002), decreased left ventricular ejection time (p < .0001), increased diastolic blood pressure (p = .01), and increased systemic vascular resistance (p =.002). Although this pattern of hemodynamic response was normal, the magnitude of the changes was considerably less than those observed previously in healthy participants. These findings warrant further investigation.

Night-time blood pressure patterns and target organ damage: a review.

BACKGROUND: Individuals who do not have a 10% to 20% reduction in blood pressure (BP) during the night are known as 'nondippers'. The cause of this nondipping phenomenon is not fully understood; however, there is a growing body of evidence linking a nondipping BP pattern with target organ damage. OBJECTIVE: To review the literature and present an overview of the target organ damage found to be associated with a nondipping BP pattern. METHODS: PubMed, CINAHL and Medscape searches of all available English language articles from 1986 to 2005 were performed. Search terms included 'BP nondipping', 'BP dipping' and 'target organ damage'. RESULTS: There is evidence to suggest that individuals with hypertension who exhibit a nondipping BP profile are at higher risk of cardiac and extracardiac morbidity and mortality. In particular, nondippers with essential hypertension have been found to have more advanced left ventricular hypertrophy, left ventricular mass and left ventricular mass index, carotid artery wall thickness, carotid artery atherosclerotic plaques, silent cerebral infarct, stroke, cognitive impairment and microalbuminuria. CONCLUSION: A better understanding of the importance of the circadian variations of BP may help to identify those at higher risk of cardiovascular morbidity and mortality, as well as lay the foundation for interventions to prevent/treat alterations in night-time BP patterns.

Endothelial function in postmenopausal women with nighttime systolic hypertension.

OBJECTIVE: Hypertension becomes more prevalent in women during their postmenopausal years. Nighttime systolic blood pressure (SBP) is especially predictive of adverse cardiac events, and the relationship between rising nighttime SBP and cardiovascular risk increases more rapidly in women compared with men. The reasons for the prognostic significance of nighttime SBP are not completely known but may involve vascular endothelial dysfunction. The purposes of this study were to examine the relationship between nighttime SBP and endothelial function, as assessed by brachial artery flow-mediated dilation (FMD), and to determine whether postmenopausal women with nighttime hypertension (SBP ≥120 mm Hg) evidenced greater endothelial dysfunction compared with women with normal nighttime SBP. METHODS: One hundred postmenopausal women (mean [SD] age, 65.8 [7.5] y; mean [SD] body mass index, 28.3 [4.7] kg/m; hypertension, 47%; coronary artery disease, 51%; mean [SD] clinic SBP, 137 [17] mm Hg; mean [SD] clinic diastolic blood pressure, 67 [11] mm Hg; nighttime hypertension, 34 women) underwent 24-hour ambulatory blood pressure monitoring, actigraphy, and brachial artery FMD assessment. RESULTS: Multivariate regression models showed that higher nighttime SBP and larger baseline artery diameter were inversely related to FMD. Nighttime SBP and baseline artery diameter accounted for 23% of the variance in FMD. After adjustment for baseline artery diameter, women with nighttime hypertension had lower mean (SD) FMD than women with normal nighttime SBP (2.95% [0.65%] vs 5.52% [0.46%], P = 0.002). CONCLUSIONS: Nighttime hypertension is associated with reduced endothelial function in postmenopausal women. Research examining the therapeutic benefits of nighttime hypertension treatment on endothelial function and future cardiovascular risk in postmenopausal women is warranted.

Reproducibility of blood pressure dipping: relation to day-to-day variability in sleep quality.

Previous studies of the reproducibility of blood pressure (BP) dipping have yielded inconsistent results. Few have examined factors that may influence day-to-day differences in dipping. Ambulatory BP monitoring was performed on three occasions, approximately 1 week apart, in 115 untreated adult subjects with elevated clinic BPs. The mean ± standard deviation BP dip was 18 ± 7/15 ± 5 mm Hg (sleep/awake BP ratio = 0.87 ± 0.05/0.82 ± 0.06), with a median (interquartile range) day-to-day variation of 5.2 (3.1-8.1)/4.3 (2.8-5.6) mm Hg. There was no decrease in variability with successive measurements. The reproducibility coefficient (5.6 [95% confidence interval, 5.1-6.1] mm Hg) was greater and the intraclass correlation coefficient (0.53 [95% confidence interval, 0.42-0.63]) was smaller for the systolic dip than for 24-hour or awake systolic BPs, suggesting greater day-to-day variability in dipping. Variability in systolic dipping was greater in subjects with higher awake BP, but was not related to age, gender, race, or body mass index. Within individuals, day-to-day variations in dipping were related to variations in the fragmentation index (P < .001), a measure of sleep quality. Although mean 24-hour and awake BPs were relatively stable over repeated monitoring days, our study confirms substantial variability in BP dipping. Day-to-day differences in dipping are related to sleep quality.

Sex differences in the endothelial function of untreated hypertension.

Vascular endothelial dysfunction is associated with increased risk for adverse cardiovascular (CV) events. However, less is known about sex differences in the endothelial function of untreated hypertensive individuals. The purpose of this study was to assess endothelial function in women and men with untreated hypertension. Ninety participants (35 women, 55 men), aged 40 to 60 years (mean age, 46.1±8.2 years), with untreated stage 1 hypertension (systolic blood pressure 140-159 mm Hg and/or diastolic blood pressure 90-99 mm Hg) underwent brachial artery endothelial-dependent flow-mediated dilation and endothelial-independent glyceryl trinitrate dilation. Women had a smaller flow-mediated dilation response than men (adjusted mean±standard error of the mean [SEM]; 1.8±0.6% vs 3.9±0.4%, P=.036), adjusting for baseline arterial diameter (P=.004), age (P=.596), ethnicity (P=.496), log shear stress ratio (P<.001), body mass index (P=.009), 24-hour diastolic blood pressure (P=.169), high-density lipoprotein (P=.225), log creatinine (P=.927), and log physical activity (P=.682). Glyceryl trinitrate dilation did not differ by sex in adjusted models. Women between the ages of 40 and 60 years with untreated stage 1 hypertension exhibited a greater impairment of endothelial function compared with their male counterparts. These findings raise the possibility that female sex may impart a greater risk of CV events in patients with untreated stage 1 hypertension potentially due to poorer endothelial function.

Nighttime blood pressure dipping in postmenopausal women with coronary heart disease.

BACKGROUND: Blunted nighttime blood pressure (BP) dipping is prognostic of cardiovascular morbidity and mortality. This relationship may be stronger among women than men. The present study hypothesized that coronary artery disease (CAD) and advancing age would be associated with reduced BP dipping in postmenopausal women. The effects of daytime physical activity and nighttime sleep quality on BP dipping were also examined. METHODS: 54 postmenopausal women with CAD (≥50% occlusion of at least one major coronary vessel) and 48 age-matched (range 50-80 years) postmenopausal women without CAD (non-CAD) underwent 24-h ambulatory BP monitoring and actigraphic evaluations of daytime physical activity and nighttime sleep efficiency. RESULTS: Women with CAD evidenced higher nighttime systolic BP (SBP) (P = 0.05) and blunted SBP dipping (P = 0.017), blunted diastolic BP (DBP) dipping (P = 0.047), and blunted pulse pressure dipping (P = 0.01), compared to non-CAD women. Multivariable regression models showed that the presence of CAD, age, daytime physical activity, and nighttime sleep efficiency were independently related to the magnitude of SBP dipping, together accounting for 25% of its variability. DBP dipping showed similar associations. CONCLUSIONS: For postmenopausal women, the presence of CAD and advancing age are accompanied by blunted nighttime BP dipping, which may increase the risk of adverse cardiovascular events. Lifestyle changes that increase daytime physical activity and improve nighttime sleep quality may help improve cardiovascular risk by enhancing nighttime BP dipping.

Blood pressure dipping: ethnicity, sleep quality, and sympathetic nervous system activity.

BACKGROUND: Blunted blood pressure (BP) dipping is an established predictor of adverse cardiovascular outcomes. Although blunted BP dipping is more common in African Americans than whites, the factors contributing to this ethnic difference are not well understood. This study examined the relationships of BP dipping to ethnicity, body mass index (BMI), sleep quality, and fall in sympathetic nervous system (SNS) activity during the sleep-period. METHODS: On three occasions, 128 participants with untreated high clinic BP (130-159/85-99 mm Hg) underwent assessments of 24-h ambulatory BP (ABP), sleep quality, (evaluated by sleep interview, self-report, actigraphy) and sleep-period fall in sympathetic activity (measured by waking/sleep urinary catecholamine excretion). RESULTS: Compared to whites (n = 72), African Americans (n = 56) exhibited higher sleep-period systolic (SBP) (P = 0.01) and diastolic BP (DBP) (P < 0.001), blunted SBP dipping (P = 0.01), greater BMI (P = 0.049), and poorer sleep quality (P = 0.02). SBP dipping was correlated with BMI (r = -0.32, P < 0.001), sleep quality (r = 0.30, P < 0.001), and sleep-period fall in sympathetic activity (r = 0.30, P < 0.001). Multiple regression analyses indicated that these three factors were independent determinants of sleep-period SBP dipping; ethnic differences in dipping were attenuated when controlling for these factors. CONCLUSIONS: Blunted BP dipping was related to higher BMI, poorer sleep quality, and a lesser decline in sleep-period SNS activity. Although African-American ethnicity also was associated with blunted dipping compared to whites in unadjusted analyses, this ethnic difference was diminished when BMI, sleep quality, and sympathetic activity were taken into account.

Improvements in heart rate variability with exercise therapy.

Heart rate variability (HRV) is a noninvasive, practical and reproducible measure of autonomic nervous system function. A heart rate that is variable and responsive to demands is believed to bestow a survival advantage, whereas reduced HRV may be associated with poorer cardiovascular health and outcomes. In recent years, many researchers have investigated the prognostic implications of HRV in a variety of clinical populations. Evidence suggests that reduced HRV has prognostic significance for individuals with myocardial infarction, chronic heart failure, unstable angina and diabetes mellitus. Interventions to increase HRV, such as exercise therapy, have also been examined. The findings of the present review suggest that exercise therapy may improve HRV in myocardial infarction, chronic heart failure and revascularization patients by increasing vagal tone and decreasing sympathetic activity. One hypothesis is that a shift toward greater vagal modulation may positively affect the prognosis of these individuals. While the underlying mechanisms by which exercise training improves vagal modulation are speculative at present, angiotensin II and nitric oxide may be potential mediators.

Stress, menopausal status and nocturnal blood pressure dipping patterns among hypertensive women.

BACKGROUND: A less than 10% decline in blood pressure during the night is known as a nondipping blood pressure (BP) pattern. Nondipping BP has been shown to be associated with target organ damage and poorer cardiovascular outcomes. Additionally, some evidence suggests that hyper-tensive nondipping women are at greater risk for target organ damage than hypertensive nondipping men. OBJECTIVE: To determine whether stress, demographics, menopausal status or sleep quality are associated with nondipping BP among hyperten-sive women. METHODS: A cross-sectional study design was used to describe the rela-tionship between stress and dipping status among a sample of hypertensive women and to describe the sample by age, ethnicity, marital status, meno-pausal status, current medications and sleep quality. RESULTS: The study sample consisted of 47 women (mean [+/- SD] age 57+/-13.9 years) with essential or office hypertension who underwent 24 h ambulatory BP monitoring, and completed stress and sleep quality measurements. Thirty-one women (66%) were classified as dippers and 16 (34%) were classified as nondippers. Nondippers were older (P=0.04), postmenopausal (P=0.003) and had lower stress scores (P=0.02) than their dipper counterparts. Postmenopausal status sig-nificantly predicted nondipping (OR 16; 95% CI 1.9 to 136.4). CONCLUSION: These findings were of interest given that some women had a nondipping BP pattern and significantly lower stress scores. It is pos-sible that there are fundamentally different physiological mechanisms that explain this nondipping phenomenon. In the future, the identification of specific hemodynamic mechanisms associated with nondipping could potentially influence the choice of antihypertensive treatment regimens for nondipper hypertensive patients.

The influence of coronary artery bypass graft harvest site on women's pain, functional status, and health services utilization throughout the first post-operative year: a longitudinal study.

BACKGROUND: Coronary artery bypass graft surgery is a commonly performed procedure aimed at managing coronary symptoms and prolonging life. Researchers have typically examined morbidity and mortality outcomes of predominantly male populations. Less is known about the influence of graft harvest site on recovery outcomes such as surgery-related pain, functional status, and health services utilization, especially in women. OBJECTIVES: We aimed to examine the relationships between coronary artery bypass graft harvest site (saphenous vein, internal mammary arteries or both) and surgery-related pain, functional status, health services use at 6 weeks, 12 weeks and 12 months post-operatively. DESIGN: Longitudinal extension survey following participation in a clinical trial. SETTING: Ten Canadian centres. PARTICIPANTS: Women (222) who participated in the Women's Recovery from Sternotomy Trial, underwent coronary artery bypass graft surgery with or without heart valve surgery, and completed the 12-month follow-up interview. METHODS: Harvest site data were collected by health record audit at the time of hospital discharge. Surgery-related pain, functional status, pain medication use and health services use data were collected by standardized interview over the telephone at 6 weeks, 12 weeks and 12 months post-operatively. Surgery-related pain and functional status were measured using the short Health Assessment Questionnaire. Health services use was measured by questionnaire and recorded as reported by the participants. RESULTS: Surgery-related pain, functional disability and health services use decreased over the first post-operative year. Participants who had left internal mammary artery grafts were more likely to have surgery-related pain (Adjusted Odds Ratio (AOR)=2.79; 95% Confidence Interval (CI) 1.40-5.70) and use pain medication (AOR=4.32; 95% CI 1.44-12.91) than those who had saphenous vein grafts. Conversely, participants who had saphenous vein grafts reported significantly more functional disability (AOR=2.63; 95% CI 1.16-6.25) over 12 months post-surgery than those with left internal mammary artery grafts. Participants who had pain over the course of follow-up were more likely to visit their family physician or nurse practitioner (p=0.017), visit another type of provider (i.e., naturopath or chiropractor, p=0.004), or use any health care service (p<0.0001). CONCLUSIONS: Following coronary artery bypass graft surgery, women who had left internal mammary artery grafts reported more pain and health services use while those who had saphenous vein grafts were more functionally disabled. Women who reported surgery-related pain also used more health services.

Ambulatory impedance cardiography in hypertension: a validation study.

The management of hypertension is improved by knowledge of the hemodynamics underlying blood pressure. Impedance Cardiography (ICG) provides data on a range of hemodynamic variables that affect blood pressure. However, ICG captures only fixed descriptions of hemodynamic characteristics. Improvements in ambulatory technology have led to the development of the Ambulatory Impedance Monitor (AIM) which records hemodynamic data during the activities of daily living. The purpose of this study was to evaluate the sensitivity of the AIM to detect hemodynamic changes associated with postural shift in persons with hypertension. Using a repeated measures cross-over design, sitting and standing hemodynamic measures were taken in seventeen persons with hypertension while wearing the AIM-BpTRU system designed for standard office use and the AIM-Spacelabs system designed for ambulatory monitoring. Both AIM-blood pressure monitoring systems detected significant changes from sitting to standing posture in heart rate (p=0.03), stroke volume (p=0.002), left ventricular ejection time (p<0.001), systemic vascular resistance (p=0.03) and diastolic blood pressure (p<0.001). Additionally, both systems generated measures of cardiac function that were positively correlated (p<0.001) and not significantly different (p>0.05). Our findings support previous work and demonstrate that the AIM provides valid and reliable estimates of cardiac function in persons with hypertension.

Exploring the use of feminist philosophy within nursing research to enhance post-positivist methodologies in the study of cardiovascular health.

Nursing has historically relied heavily on scientific knowledge. It is not surprising that the cardiovascular health literature has been highly influenced by the post-positivist philosophy. The nursing discipline, as well as the cardiovascular nursing specialty, continues to benefit from research grounded within this philosophical tradition. At the same time, there are limitations associated with post-positivism. Therefore, it is beneficial for researchers and clinicians to examine the potential contributions various philosophical traditions can have for their research and practice. This paper is an exploration of the compatibilities of feminist and post-positivist philosophies in the study of cardiovascular nursing research. The ensuing discussion entails an examination of my clinical and research interests, the grounding of my research within the post-positivist perspective and the significant contribution feminist philosophy can make to my research.