Three measures of left ventricular (LV) performance derived from pressure (P)-volume (V) loops have been proposed: the end-systolic P-V (PES-VES) relation, the stroke workend-diastolic V (SW-VED) relation, and maximum dP/dt-VED (dP/dtmax-VED) relation. We evaluated the variability of repeated determinations, and inotropic and load sensitivity of these relations in conscious dogs. LVV was determined from three orthogonal LV diameters measured by sonomicrometry. Three to six sets of variably loaded P-V loops were generated by transient caval occlusions before and again after increasing inotropic state by infusing dobutamine (6±1 ug/kg/min, mean+SD) and after increasing PEs by 49±17 mm Hg with phenylephrine following autonomic blockade. The slope (Msw) of the SW-VED relation was the least variable at constant inotropic state (coefficient of variation, 4±N3%) compared with the slope (EES) of the PES-VEs relation (8+±3%) or the slope (dE/dtmax) of the dP/dtmax-VED relation (11±6%, p
We evaluated whether black race is associated with higher incidence of End Stage Renal Disease (ESRD) among a cohort of blacks and whites of similar, generally low socioeconomic status, and whether risk factor patterns differ among blacks and whites and explain the poorly understood racial disparity in ESRD. Incident diagnoses of ESRD among 79,943 black and white participants in the Southern Community Cohort Study (SCCS) were ascertained by linkage with the United States Renal Data System (USRDS) from 2002 through 2009. Person-years of follow up were calculated from date of entry into the SCCS until date of ESRD diagnosis, date of death, or September 1, 2009, whichever occurred first. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CI) for incident ESRD among black and white participants in relation to baseline characteristics. After 329,003 person-years of follow-up, 687 incident cases of ESRD were identified in the cohort. The age-adjusted ESRD incidence rate was 273 (per 100,000) among blacks, 3.5-fold higher than the rate of 78 among whites. Risk factors for ESRD included male sex (HR = 1.6; 95% CI 1.4–1.9), low income (HR = 1.5; 95% CI 1.2–1.8 for income below vs. above $15,000), smoking (HR = 1.2; 95% CI 1.02–1.4) and histories of diabetes (HRs increasing to 9.4 (95% CI 7.4–11.9) among those with ≥20 years diabetes duration) and hypertension (HR = 2.9; 95% CI 2.3–3.7). Patterns and magnitudes of association were virtually identical among blacks and whites. After adjustment for these risk factors, blacks continued to have a higher risk for ESRD (HR = 2.4; 95% CI = 1.9–3.0) relative to whites. The black-white disparity in risk of ESRD was attenuated but not eliminated after control for known risk factors in a closely socioeconomically matched cohort. Further research characterizing biomedical factors, including CKD progression, in ESRD occurrence in these two racial groups is needed.
Background Abdominal aortic aneurysm (AAA) is a leading cause of death in the USA. We evaluated the incidence and predictors of AAA in a prospectively followed cohort. Methods We calculated age-adjusted AAA incidence rates (IR) among 18 782 participants aged ≥65 years in the Southern Community Cohort Study who received Medicare coverage from 1999–2012, and assessed predictors of AAA using multivariable Cox proportional hazards models, overall and stratified by sex, adjusting for demographic, lifestyle, socioeconomic, medical and other factors. HRs and 95% CIs were calculated for AAA in relation to factors ascertained at enrolment. Results Over a median follow-up of 4.94 years, 281 cases were identified. Annual IR was 153/100 000, 401, 354 and 174 among blacks, whites, men and women, respectively. AAA risk was lower among women (HR 0.48, 95% CI 0.36 to 0.65) and blacks (HR 0.51, 95% CI 0.37 to 0.69). Smoking was the strongest risk factor (former: HR 1.91, 95% CI 1.27 to 2.87; current: HR 5.55, 95% CI 3.67 to 8.40), and pronounced in women (former: HR 3.4, 95% CI 1.83 to 6.31; current: HR 9.17, 95% CI 4.95 to 17). A history of hypertension (HR 1.44, 95% CI 1.04 to 2.01) and myocardial infarction or coronary artery bypass surgery (HR 1.9, 95% CI 1.37 to 2.63) was negatively associated, whereas a body mass index ≥25 kg/m2 (HR 0.72; 95% CI 0.53 to 0.98) was protective. College education (HR 0.6, 95% CI 0.37 to 0.97) and black race (HR 0.44, 95% CI 0.28 to 0.67) were protective among men. Conclusions Smoking is a major risk factor for incident AAA, with a strong and similar association between men and women. Further studies are needed to evaluate benefits of ultrasound screening for AAA among women smokers.
BackgroundCardiac rehabilitation (CR) is underutilized in the United States, with fewer than 20% of eligible patients participating in CR programs. Individual socioeconomic status is associated with CR utilization, but data regarding neighborhood characteristics and CR are sparse. We investigated the association of neighborhood socioeconomic context with CR participation in the SCCS (Southern Community Cohort Study).Methods and ResultsThe SCCS is a prospective cohort study of 84 569 adults in the southeastern United States from 2002 to 2009, 52 117 of whom have Medicare or Medicaid claims. Using these data, we identified participants with hospitalizations for myocardial infarction, percutaneous coronary intervention, or coronary artery bypass surgery and ascertained their CR utilization. Neighborhood socioeconomic context was assessed using a neighborhood deprivation index derived from 11 census‐tract level variables. We analyzed the association of CR utilization with neighborhood deprivation after adjusting for individual socioeconomic status. A total of 4096 SCCS participants (55% female, 57% black) with claims data were eligible for CR. CR utilization was low, with 340 subjects (8%) participating in CR programs. Study participants residing in the most deprived communities (highest quintile of neighborhood deprivation) were less than half as likely to initiate CR (odds ratio 0.42, 95% confidence interval, 0.27–0.66, P<0.001) as those in the lowest quintile. CR participation was inversely associated with all‐cause mortality (hazard ratio 0.77, 95% confidence interval, 0.60–0.996, P<0.05).ConclusionsLower neighborhood socioeconomic context was associated with decreased CR participation independent of individual socioeconomic status. These data invite research on interventions to increase CR access in deprived communities.
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