Living Arrangement: a Contributor to Vascular Disease in Asymptomatic African American Women

Background: Diminished social support has shown to lead to worse cardiovascular outcomes and since cardiovascular disease (CVD) is the leading cause of death in the United States (U.S.), it is critical to non-invasively study its precursor- vascular disease (VD). Assessing the impact social support has on vascular outcomes can unveil potential CVD susceptibilities in at-risk populations. African American women exhibit the greatest burden of CVD morbidity and mortality; therefore, the purpose of this study is to examine the association between living arrangement/social support and impaired vascular function in asymptomatic African American women. Methods: Vascular function was assessed by a non-invasive screening tool, HDI/PulseWave CR-2000, during screenings at community outreach events on participants clinically free of CVD. Vascular disease was defined as abnormal/impaired vascular function. Living arrangement, a binary variable (living with someone/living alone), was determined by survey responses (N=67) and represented social support. Multivariable analyses were used to estimate adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) to determine the association between living arrangement and vascular disease after controlling for confounders. Analyses were conducted using SAS 9.2. Results: Of those who lived alone, 82% had vascular disease (p=0.03). After adjusting for family CVD, and other CVD risk factors, those who lived with a spouse/partner or relative were 78% (p=0.04) less likely to develop vascular disease (AOR=0.22; 95% CI=0.05, 0.98). Conclusions: Our study provides preliminary evidence to suggest that among African American women, clinically free of CVD, living arrangement is associated with vascular disease. While living alone may place individuals at an increased risk of CVD because of the association, living with a spouse/partner or relative may act as a protective factor against vascular disease and reduce the risk of CVD. Public health practitioners may use individuals’ living arrangement as preventive measure for CVD risk

Determinants of exercise capacity and prognosis in dilated cardiomyopathy : contribution of left ventricular diastolic function and mitral regurgitation

This original work aimed to further evaluate the central cardiac determinants of exercise capacity impatients with dilated cardiomyopathy (DCM) and chronic heart failure (CHF), namely the relative contribution of left ventricular (LV) diastolic filling and mitral regurgitation (MR) and their prognostic relevance. Indeed, the present thesis issue not only provides a more robust definition on the relationship, between diastolic filling and exercise capacity as well as the pathophysiological basis of exercise impairment in CHF, but also allowed an appropriate prognostic stratification of patients involved with this disorder. We first examined in a more quantitative way the potential relationship between indices of diastolic filling and systolic function (assessed by Doppler echocardiography and radionuclide ventriculography) and exercise capacity (quantitatively determined as total body peak oxygen uptake or peak VO2 during a symptom-limited bycicle or treadmill exercise). We also evaluated the robustness of these measurements in terms of reproducibility of our findings, the effects of postural changes and mode of exercise on these possible relationships between LV diastolic filling indices (namely the E/A ratio) and exercise data (peak VO2). The data indicate that indices of diastolic filling rather than systolic function were independent explanators of peak VO2. Since they also supported the existence of an independent contribution of the severity of MR to peak VO2, we then attempted to define the exact mechanisms responsible for the observed relationship. The present study is the first indication that exercise-induced changes in the severity of MR limit stroke volume adaptation during exercise, and could therefore contribute to limit exercise capacity in patients with DCM and chronic low-output heart failure. Because these indices were strongly correlated with exercise capacity, which is a powerful prognostic indicator, our second goal was to determine their prognostic information. A prognostic study was then conducted in a large cohort of consecutive patients with DMC of ischemic and non-ischemic origin. During t a long mean follow-up of 62 months, we found that these indices were independently associated with the risk of cardiac events (cardiac death or the need for heart transplantation) related to this disorder irrespective of the etiology. Based on clinical and echocardiographic parameters identified by the Cox analyses, a risk score was elaborated, and allowed appropriate classification of individual patients into risk group (to die or to require heart transplantation). The data indicate thus that the prognostic of these patients is strikingly related to the degree of residual LV diastolic performance. In conclusion, the assessment of LV diastolic filling provides comprehensive information of the filling pressures, the exercise capacity, and the prognosis in patients with DCM. Doppler-derived LV filling pattern, namely E/A ratio, is particularly appealing because it is easy to measure, readily available for daily clinical decision making without any risk for the patient. Closely related to VO2, E/A ratio which is measured at rest may reliably predict exercise capacity and prognosisThèse de doctorat en sciences biomédicales (cardiologie) -- UCL, 199

Relation of exercise capacity to left ventricular systolic function and diastolic filling in idiopathic or ischemic dilated cardiomyopathy

Although exercise intolerance is a cardinal symptom of patients with dilated cardiomyopathy (DC) and heart failure, the factors that limit exercise capacity in these patients remain a matter of debate. To assess the contribution of left ventricular (LV) diastolic filling to the variable exercise capacity of patients with DC, we studied 47 patients (60 +/- 12 years) with DC in stable mild-to-moderate heart failure with a mean LV ejection fraction of 28%. Exercise capacity was measured as total body peak oxygen consumption (VO2) during symptom-limited bicycle (10 W/min) and treadmill (modified Bruce protocol) exercise. LV systolic function and diastolic filling were assessed at rest before each exercise by M-mode, Doppler echocardiography, and radionuclide ventriculography. As expected, treadmill exercise always yielded higher peak VO2 than bicycle exercise (21 +/- 6 vs 18 +/- 5 ml/kg/min, range 12 to 35 and 7 to 30 ml/kg/min, respectively, p <0.001). Both of these VO2 measurements were highly reproducible (R = 0.98). With univariate analysis, close correlations were found between peak VO2 (with either exercise modalities) and Doppler indexes of LV diastolic filling, as well as with the radionuclide LV ejection fraction. Stepwise multiple regression analysis identified 3 nonexercise variables as independent correlates of peak VO2, of which the most powerful was the E/A ratio (multiple r2 = 0.38, p <0.0001), followed by peak A velocity (r2 = 0.54, p <0.0001) and mitral regurgitation grade (r2 = 0.58, p = 0.024). In conclusion, our data indicate that in patients with DC, peak VO2 is better correlated to diastolic filling rather than systolic LV function

COMPARATIVE FREQUENCY OF ANGIOGRAPHIC CORONARY ARTERY DISEASE IN AFRICAN AMERICANS AND HISPANICS

https://www.ethndis.org/priorarchives/ethn-16-01-58.pd

Contribution of exercise-induced mitral regurgitation to exercise stroke volume and exercise capacity in patients with left ventricular systolic dysfunction.

BACKGROUND: Functional mitral regurgitation (MR) is common in patients with heart failure and left ventricular (LV) dysfunction, and its severity may vary over time, depending primarily on the loading conditions. Because dynamic changes in the severity of functional MR may affect forward stroke volume, we hypothesized that exercise-induced changes in MR severity influence the stroke volume response of patients with LV dysfunction to exercise, and hence their exercise capacity. METHODS AND RESULTS: Heart failure patients (n=25; mean age 53+/-12 years) with LV dysfunction underwent dynamic bicycle exercise at steady-state levels of 30%, 60%, and 90% of predetermined peak VO2. During each exercise level, right heart pressures, cardiac output, VO2, and MR severity were measured simultaneously. During exercise, MR severity, as evaluated by the ratio of MR jet over left atrium area, increased from 15+/-8% to 33+/-15%. Peak VO2, exercise-induced changes in stroke volume, and those in capillary wedge pressure correlated with the changes in MR (r=-0.55, -0.87, and 0.62, respectively, P<0.01). The changes in MR severity also correlated with those in end-diastolic (r=-0.75, P<0.01) and end-systolic (r=-0.72, P<0.01) sphericity indexes and those in the coaptation distance (r=0.86, P<0.01). CONCLUSIONS: Our data indicate that in patients with LV dysfunction, exercise-induced changes in MR severity limit the stroke volume adaptation during exercise and therefore contribute to limitation of exercise capacity