Citations

Markers of inflammation are predictive of cardiovascular events but their association with atherosclerotic burden remains poorly defined. We hypothesized that markers of inflammation, including C-reactive protein (CRP), white blood cell (WBC) count, and lipoprotein-associated phospholipase A2 (Lp-PLA2), would be associated with the ankle-brachial index (ABI), a marker of atherosclerotic burden. Subjects were 247 patients referred for lower extremity arterial evaluation to the non-invasive vascular laboratory excluding those with active infection or lower extremity revascularization within the previous year. ABI was measured at two sites in both legs and the lowest of four measurements was used in the analyses. CRP was measured by a high-sensitivity immunoturbidimetric assay and Lp-PLA2 was measured by ELISA. The mean patient age was 68±11 years, and 54% were men. Mean ABI was 0.84-0.31 and 49% had an ABI < 0.9. Age, hypertension, fasting plasma glucose, and ‘ever’ smoking were independently associated with the ABI. Spearman correlation coefficients of inflammatory markers with the ABI were: CRP (r 1/4-0.15, p 1/4-0.02), WBC count (r 1/4-0.27, p 1/4-0.001), and Lp-PLA2 (r 1/4-0.09, p 1/4-0.21). In a multiple regression model that included conventional risk factors and statin use, CRP and WBC count were no longer significantly associated with ABI, whereas Lp-PLA2 was a borderline-significant predictor of lower ABI (p 1/4-0.05). These data indicate that CRP and WBC count are not independently associated with ABI, a marker of atherosclerotic burden in subjects referred for non-invasive lower extremity arterial evaluation. The association of Lp-PLA2 with ABI merits further study.

Background— Preclinical systolic or diastolic dysfunction is associated with increased morbidity and mortality. We postulated that plasma brain natriuretic peptide (BNP) might serve as a biomarker for preclinical ventricular dysfunction (PCVD) but that the discriminatory values for BNP may vary with age and sex. Methods and Results— We measured BNP, systolic and diastolic ventricular function, and clinical parameters in 2042 randomly selected residents of Olmsted County, Minn, aged 45 years or older. For preclinical systolic dysfunction, the areas under the receiver operating characteristics curve were higher for those with more severe (0.82 to 0.92) than any (0.51 to 0.74) systolic dysfunction and were similar in men and women and in younger and older persons. For preclinical diastolic dysfunction, the areas under the receiver operating characteristics curve were higher for those with moderate-to-severe (0.74 to 0.79) than any (0.52 to 0.68) diastolic dysfunction and were similar regardless of age or sex. Optimal discriminatory values of BNP varied with age and sex. Considering the prevalence of preclinical systolic or diastolic dysfunction and the predictive characteristics observed, using BNP to screen for PCVD would necessitate echo in 10% to 40% of those screened, with most confirmatory echocardiograms being negative, and would miss 10% to 60% of those affected. Conclusions— BNP is a suboptimal screening test for PCVD in the population.

Few studies have investigated whether ethnic groups differ in the prevalence of peripheral arterial disease (PAD). We compared the distribution of the ankle-brachial index (ABI), a measure of PAD, between African Americans and non-Hispanic white individuals. Subjects (n = 931) belonged to the Genetic Epidemiology Network of Arteriopathy (GENOA) study, a community-based study of hypertensive sibships, and included 453 African Americans from Jackson, Mississipi (mean age 72 6 years, 69% women) and 478 non-Hispanic white individuals from Rochester, Minnesota (mean age 58 7 years, 64% women). ABI was determined at two sites in each lower extremity and the lowest of four indices was used in the analyses. PAD was defined as an ABI of 0.95. Information about conventional risk factors was derived from interviews and from blood samples drawn at the study visit. The prevalence of diabetes and hypertension was significantly higher in African Americans than in non-Hispanic white individuals. After adjusting for age, African American subjects had a lower mean ABI (women 0.97 vs 1.04, p < 0.001; men 0.96 vs 1.12, p < 0.001) and a greater prevalence of PAD (women 34% vs 22%, p = 0.010; men 33% vs 11%, p < 0.001) than their non-Hispanic white counterparts. In multiple regression analyses, African American ethnicity was a predictor of a lower ABI and the presence of PAD in each sex after adjusting for age and other conventional risk factors. In conclusion, the lower ABI and greater prevalence of PAD in African Americans than in non-Hispanic white individuals is not explained by differences in conventional risk factors. Identifying additional ‘novel’ risk factors that account for the ethnic differences in PAD is an important next step towards understanding why such differences exist and developing more effective strategies to reduce the burden of PAD.

Background— After acute myocardial infarction (AMI), diastolic function assessed by Doppler echocardiography provides important prognostic information that is incremental to systolic function. However, Doppler variables are affected by multiple factors and may change rapidly. In contrast, left atrial (LA) volume is less influenced by acute changes and reflects subacute or chronic diastolic function. This may be of importance when one assesses risk in patients with AMI. Methods and Results— Three hundred fourteen patients with AMI who had a transthoracic echocardiogram with assessment of left ventricular (LV) systolic and diastolic function and measurement of LA volume during admission were identified. The LA volume was corrected for body surface area, and the population was divided according to LA volume index of 32 mL/m 2 (2 SDs above normal). LA volume index was >32 mL/m 2 in 142 (45%). The primary study end point was all-cause mortality. During follow-up of 15 (range 0 to 33) months, 46 patients (15%) died. LA volume index was a powerful predictor of mortality and remained an independent predictor (hazard ratio 1.05 per 1-mL/m 2 change, 95% CI 1.03 to 1.06, P <0.001) after adjustment for clinical factors, LV systolic function, and Doppler-derived parameters of diastolic function. Conclusions— Increased LA volume index is a powerful predictor of mortality after AMI and provides prognostic information incremental to clinical data and conventional measures of LV systolic and diastolic function.

Objective— This study was undertaken to examine the association between bicuspid aortic valve (BAV) and aortic dilatation in the community. The association between BAV and aortic dilatation has been reported predominantly in retrospective studies in patients mostly with valvular dysfunction or selected surgical patients from tertiary referral centers. An independent association of BAV and aortic dilatation in a community-based study has not been demonstrated. Methods and Results— In a geographically defined population of Olmsted County, Minnesota, residents with BAV (n=44, age 35±13 years) without hemodynamically significant obstruction or regurgitation and matched controls with normal tricuspid aortic valves were identified by transthoracic echocardiography. The two groups were compared with respect to measurements of the aorta. The BAV and control groups differed with respect to size of the aortic anulus (23.2±2.4 versus 21.6±2.4 mm; P =0.002), aortic sinus (33.5±4.6 versus 30.3±4.1 mm; P =0.0001), and proximal ascending aorta (33.3±6.5 versus 27.9±3.6 mm; P =0.0001). There was no difference in the size of the aortic arch (24.2±3.6 versus 25.3±3.4 mm; P =0.16). These differences were maintained when the groups were stratified by sex and blood pressure. The relationship between bicuspid aortic valve and aortic dilatation was maintained when adjusting for factors related to fluid mechanics and hemodynamics such as systolic blood pressure, diastolic blood pressure, left ventricular ejection time, and peak aortic valve velocity. Conclusions— In a community-based study, BAV is associated with an alteration of aortic dimensions even in the absence of hemodynamically significant aortic valve stenosis or regurgitation.

Abstract Background Digitalis has a long history in the treatment of heart failure but its effects on cardiac hemodynamics and neurohormonal modulation are not well characterized. Aims The purpose of this study was to evaluate the relationship between atrial natriuretic peptide (ANP) and the hemodynamic responses to acute digitalis administration in patients with normal and impaired left ventricular function (LVD). Methods and Results Thirty patients were enrolled in the study, 20 with LVD (LVEF-22±8%) and 10 control subjects (LVEF-77±10%). Hemodynamics and plasma ANP concentrations were measured supine and with leg elevation before and after digitalis. In patients with normal ventricular function, the hemodynamic stress of leg elevation in the pre-digitalis state resulted in significant (P&lt;0.05) increases in PAWP and MPAP. Digitalis administration in the supine position produced reductions in heart rate, PAWP, MPAP and CI; SVR was increased. In LVD patients leg elevation further increased PAWP, RAP and MPAP. Digitalis in the supine position, however, reduced RAP, MPAP and PAWP and increased CI. These improved hemodynamics were preserved during the stress of leg elevation. Leg elevation following digitalis resulted in increased ANP concentrations despite decreased cardiac filling pressures. Conclusions Acute digitalis administration results in hemodynamic improvement in LVD patients which may in part result from digitalis stimulated release of myocardial ANP under conditions of hemodynamic stress.

Background— The outcome of mitral valve prolapse (MVP) is controversial, with marked discrepancies in reported complication rates. Methods and Results— We conducted a community study of all Olmsted County, Minn, residents first diagnosed with asymptomatic MVP between 1989 and 1998 (N=833). Diagnosis, motivated by auscultatory findings (n=557) or incidental (n=276), was always confirmed by echocardiography with the use of current criteria. End points analyzed during 4581 person-years of follow-up were mortality (n=96, 19±2% at 10 years), cardiovascular morbidity (n=171), and MVP-related events (n=109, 20±2% at 10 years). The most frequent primary risk factors for cardiovascular mortality were mitral regurgitation from moderate to severe ( P =0.002, n=131) and, less frequently, ejection fraction <50% ( P =0.003, n=31). Secondary risk factors independently predictive of cardiovascular morbidity were slight mitral regurgitation, left atrium ≥40 mm, flail leaflet, atrial fibrillation, and age ≥50 years (all P <0.01). Patients with only 0 or 1 secondary risk factor (n=430) had excellent outcome, with 10-year mortality of 5±2% ( P =0.17 versus expected), cardiovascular morbidity of 0.5%/y, and MVP-related events of 0.2%/y. Patients with ≥2 secondary risk factors (n=250) had mortality similar to expected ( P =0.20) but high cardiovascular morbidity (6.2%/y, P <0.01) and notable MVP-related events (1.7%/y, P <0.01). Patients with primary risk factors (n=153) showed excess 10-year mortality (45±9%, P =0.01 versus expected), high morbidity (18.5%/y, P <0.01), and high MVP-related events (15%/y, P <0.01). Conclusions— Natural history of asymptomatic MVP in the community is widely heterogeneous and may be severe. Clinical and echocardiographic characteristics allow separation of the majority of patients with excellent prognosis from subsets of patients displaying, during follow-up, high morbidity or even excess mortality as direct a consequence of MVP.