Sex- and age-related differences in the predictive capability of circulating biomarkers: from the MONICA 10 cohort

OBJECTIVES

The purpose of this study was to assess whether high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP), and soluble urokinase plasminogen activator receptor (suPAR) differed in their ability to predict cardiovascular outcomes beyond traditional risk factors in younger and older men and women without known cardiovascular disease. Design. Prospective population-based cohort study of 1951 individuals from the MONItoring of trends and determinants in Cardiovascular disease (MONICA) study, examined 1993-1994. Participants were stratified into four groups based on sex and age. Subjects aged 41 or 51 years were classified as younger; those aged 61 or 71 years were classified as older. The principal endpoint was death from cardiovascular causes. Predictive capabilities of biomarkers were tested using Cox proportional-hazards regression, Harrell's concordance-index, net reclassification improvement, and classification and regression tree (CART) analysis. Results. Median follow-up was 18.5 years, during which 19/597 younger men, 100/380 older men, 12/607 younger women, and 46/367 older women had died from a cardiovascular cause. NT-proBNP was independently associated with death from cardiovascular causes among all participants (p ≤ .02) except younger women (p = .70), whereas hs-CRP was associated with this endpoint in men (p ≤ .007), and suPAR in older men only (p < .001). None of the biomarkers improved discrimination ability beyond traditional risk factors (p ≥ .07). However, NT-proBNP enhanced reclassification in men and older women. CART-analysis showed that NT-proBNP was generally of greater value among men, and suPAR among women. Conclusions. Hs-CRP, NT-proBNP, and suPAR displayed different associations with cardiovascular death among apparently healthy younger and older men and women.

Association between antecedent blood pressure, hypertension-mediated organ damage and cardiovascular outcome

Purpose: The objective of this study was to test if combining antecedent systolic blood pressure (SBP) with traditional risk factors and hypertension-mediated organ damage (HMOD) improves risk stratification for subsequent cardiovascular disease.Materials and methods: 1910 subjects participated in this study. Antecedent SBP was defined as the average of measurements obtained in 1982 and in 1987. Current SBP was obtained in 1993. HMOD were examined in 1993. HMOD was defined as either atherosclerotic plaque(s), increased pulse wave velocity, increased urine albumin creatinine ratio (above the 90th percentile) or left ventricular hypertrophy. Major adverse cardiovascular events (MACE) including myocardial infarction, cerebrovascular disease, heart failure and arrhythmia were obtained from national registries.Results: Subjects were divided into two age categories: a middle-aged group (aged 41 or 51) and an older group (aged 61 or 71). From 1993 to 2010, 425 events were observed. In multivariable analysis with both current and antecedent SBP adjusted for traditional risk factors, current SBP was associated with each measure of HMOD whilst antecedent SBP was not significantly associated with urine albumin creatinine ratio in the older group, LVMI in the middle-aged group, or the presence of plaque in any of the age groups (all p > 0.15). When current and antecedent SBP were evaluated together, current SBP was not associated with MACE in the middle-aged subgroup [HR = 1.09 (0.96-1.22), p = 0.18] but remained associated with MACE in the older subgroup [HR = 1.21 (1.10-1.34), p < 0.01]. Contrariwise, antecedent SBP was only associated with MACE in the middle-aged subgroup [HR = 1.24 (1.04-1.48), p = 0.02]. Adding antecedent SBP to traditional risk factors did not improve the predictive accuracy of the survival model.Conclusion: In healthy non-medicated middle-aged subjects, antecedent SBP is associated with cardiovascular outcome independently of current BP, traditional risk factors and HMOD. However, improvement in risk stratification seems to be limited.

Impact of Age and Target-Organ Damage on Prognostic Value of 24-Hour Ambulatory Blood Pressure

Markers of target-organ damage and 24-hour ambulatory blood pressure (BP) measurement improve cardiovascular risk stratification. The prevalence of target-organ damage and raised BP increases with aging. The study aim was to evaluate the impact of age and target-organ damage on the prognostic value of ambulatory BP. Markers of target-organ damage and ambulatory BP were measured in 1408 healthy people aged 41 or 51 (middle-aged group), and 61 or 71 (older group) years. The primary outcome was cardiovascular events after 16 years of follow-up, with data obtained from national registries. The prognostic value of BP was evaluated with Cox regression models, adjusted for traditional risk factors and target-organ damage, including left ventricular mass, pulse wave velocity, carotid plaques, and urine albumin/creatinine ratio. A total of 323 events were observed. In comparison with traditional risk factors, adding systolic BP and presence of target-organ damage improved risk stratification by increasing concordance index from 0.711 to 0.728 ( P =0.01). In middle-aged subjects with target-organ damage, increment in pulse pressure (hazard ratio, 1.70; 95% confidence interval, 1.31–2.21; P <0.01) and increment in average real variability (hazard ratio, 1.29; 95% confidence interval, 1.05–1.59; P =0.02) were associated with a greater risk of cardiovascular disease compared with subjects without target-organ damage: hazard ratio, 1.04 (95% confidence interval, 0.74–1.46; P =0.81); P for interaction, 0.02; and hazard ratio, 0.89 (95% confidence interval, 0.69–1.14; P =0.36); P for interaction, 0.01. Target-organ damage may be a marker of individual susceptibility to the harmful effects of pulse pressure and BP variability on the cardiovascular system in middle-aged individuals.

Uncontrolled hypertension is associated with coronary artery calcification and electrocardiographic left ventricular hypertrophy: a case-control study

We conducted a 1:2 matched case-control study in order to evaluate whether the prevalence of coronary artery calcium (CAC) and electrocardiographic left ventricular hypertrophy (LVH) or strain was higher in patients with uncontrolled hypertension than in subjects from the general population, and evaluate the association between CAC and LVH in patients with uncontrolled hypertension. Cases were patients with uncontrolled hypertension, whereas the controls were random individuals from the general population without cardiovascular disease. CAC score was assessed using a non-contrast computed tomographic scan. LVH was evaluated using the Sokolow-Lyon voltage combination and Cornell voltage-duration product, respectively. Associations between CAC, LVH and traditional cardiovascular risk factors were tested by means of ordinal, conditional and classic binary logistic regression models. We found that uncontrolled hypertension was independently associated with both an ordinal CAC score category (odds ratio (OR) 3.9 (95% CI, 1.6-9.1), P = 0.002), the presence of CAC score>99 (OR 4.5 (95% CI, 1.4-14.7), P = 0.01) and electrocardiographic LVH (OR 10.1 (95% CI, 3.4-30.2), P < 0.001) on both univariate and multivariable analyses. There was, however, no correlation between CAC and LVH. The lack of an association between CAC and LVH suggests that they are markers of different complications of hypertension and may have independent predictive values. Patients with both CAC and LVH may be at higher risk than those in whom only one of these markers is present.