Cardiac Troponin I and Incident Stroke in European Cohorts Insights From the BiomarCaRE Project

Background and Purpose: Stroke is a common cause of death and a leading cause of disability and morbidity. Stroke risk assessment remains a challenge, but circulating biomarkers may improve risk prediction. Controversial evidence is available on the predictive ability of troponin concentrations and the risk of stroke in the community. Furthermore, reports on the predictive value of troponin concentrations for different stroke subtypes are scarce. Methods: High-sensitivity cardiac troponin I (hsTnI) concentrations were assessed in 82 881 individuals (median age, 50.7 years; 49.7% men) free of stroke or myocardial infarction at baseline from 9 prospective European community cohorts. We used Cox proportional hazards regression to determine relative risks, followed by measures of discrimination and reclassification using 10-fold cross-validation to control for overoptimism. Follow-up was based upon linkage with national hospitalization registries and causes of death registries. Results: Over a median follow-up of 12.7 years, 3033 individuals were diagnosed with incident nonfatal or fatal stroke (n=1654 ischemic strokes, n=612 hemorrhagic strokes, and n=767 indeterminate strokes). In multivariable regression models, hsTnI concentrations were associated with overall stroke (hazard ratio per 1-SD increase, 1.15 [95% CI, 1.10-1.21]), ischemic stroke (hazard ratio, 1.14 [95% CI, 1.09-1.21]), and hemorrhagic stroke (hazard ratio, 1.10 [95% CI, 1.01-1.20]). Adding hsTnI concentrations to classical cardiovascular risk factors (C indices, 0.809, 0.840, and 0.736 for overall, ischemic, and hemorrhagic stroke, respectively) increased the C index significantly but modestly. In individuals with an intermediate 10-year risk (5%-20%), the net reclassification improvement for overall stroke was 0.038 (P=0.021). Conclusions: Elevated hsTnI concentrations are associated with an increased risk of incident stroke in the community, irrespective of stroke subtype. Adding hsTnI concentrations to classical risk factors only modestly improved estimation of 10-year risk of stroke in the overall cohort but might be of some value in individuals at an intermediate risk.</div

Impact of Age on the Importance of Systolic and Diastolic Blood Pressures for Stroke Risk:The MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project

This study investigates age-related shifts in the relative importance of systolic (SBP) and diastolic (DBP) blood pressures as predictors of stroke and whether these relations are influenced by other cardiovascular risk factors. Using 34 European cohorts from the MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project with baseline between 1982 and 1997, 68 551 subjects aged 19 to 78 years, without cardiovascular disease and not receiving antihypertensive treatment, were included. During a mean of 13.2 years of follow-up, stroke incidence was 2.8%. Stroke risk was analyzed using hazard ratios per 10-mm Hg/5-mm Hg increase in SBP/DBP by multivariate-adjusted Cox regressions, including SBP and DBP simultaneously. Because of nonlinearity, DBP was analyzed separately for DBP ≥71 mm Hg and DBP <71 mm Hg. Stroke risk was associated positively with SBP and DBP ≥71 mm Hg (SBP/DBP ≥71 mm Hg; hazard ratios: 1.15/1.06 [95% CI: 1.12–1.18/1.03–1.09]) and negatively with DBP <71 mm Hg (0.88[0.79–0.98]). The hazard ratio for DBP decreased with age (P<0.001) and was not influenced by other cardiovascular risk factors. Taking into account the age×DBP interaction, both SBP and DBP ≥71 mm Hg were significantly associated with stroke risk until age 62 years, but in subjects older than 46 years the superiority of SBP for stroke risk exceeded that of DBP ≥71 mm Hg and remained significant until age 78 years. DBP <71 mm Hg became significant at age 50 years with an inverse relation to stroke risk. In Europeans, stroke risk should be assessed by both SBP and DBP until age 62 years with increased focus on SBP from age 47 years. From age 62 years, emphasis should be on SBP without neglecting the potential harm of very low DBP

Does Estimated Pulse Wave Velocity Add Prognostic Information?:MORGAM Prospective Cohort Project

The Reference Values for Arterial Stiffness Collaboration has derived an equation using age and mean blood pressure to estimated pulse wave velocity (ePWV), which predicted cardiovascular events independently of Systematic COoronary Risk Evaluation (SCORE) and Framingham Risk Score. The study aim was to investigate the independent association between ePWV and clinical outcomes in 107 599 apparently healthy subjects (53% men) aged 19 to 97 years from the MORGAM Project who were included between 1982 and 2002 in 38 cohorts from 11 countries. Using multiple Cox-regression analyses, the predictive value of ePWV was calculated adjusting for country of inclusion and either SCORE, Framingham Risk Score, or traditional cardiovascular risk factors (age, sex, smoking, systolic blood pressure, body mass index [BMI], total and high-density lipoprotein cholesterol). Cardiovascular mortality consisted of fatal stroke, fatal myocardial infarction, or coronary death, and the composite cardiovascular end point consisted of stroke, myocardial infarction, or coronary death. Model discrimination was assessed using Harrell's C-statistic. Adjusting for country and logSCORE or Framingham Risk Score, ePWV was associated with all-cause mortality (hazard ratio, 1.23 [95% CI 1.20-1.25] per m/s or 1.32 [1.29-1.34]), cardiovascular mortality (1.26 [1.21-1.32] or 1.35 [1.31-1.40]), and composite cardiovascular end point (1.19 [1.16-1.22] or 1.23 [1.20-1.25]; all P<0.001). However, after adjusting for traditional cardiovascular risk factors, ePWV was only associated with all-cause mortality (1.15 [1.08-1.22], P<0.001) and not with cardiovascular mortality (0.97 [0.91-1.03]) nor composite cardiovascular end point (1.10 [0.97-1.26]). The areas under the last 3 receiver operator characteristic curves remained unchanged when adding ePWV. Elevated ePWV was associated with subsequent mortality and cardiovascular morbidity independently of systematic coronary risk evaluation and Framingham Risk Score but not independently of traditional cardiovascular risk factors

Predictive Importance of Blood Pressure Characteristics With Increasing Age in Healthy Men and Women:The MORGAM Project

It remains unclear which blood pressure (BP) characteristics best predict cardiovascular risk in different age groups and between sexes. We leveraged data from the MORGAM (MONICA [Monitoring of Trends and Determinants in Cardiovascular Disease], Risk, Genetics, Archiving and Monograph) Project to investigate determinants of BP characteristics and their prognostic importance, in younger and older (</≥50 years) men and women. The study population comprised 107 599 individuals (53% men) aged 19 to 97 years without established cardiovascular disease, not on antihypertensive treatment, recruited between 1982 and 2008 in 38 cohorts. Covariates of BP characteristics were explored using multivariable linear regression. Prognostic importance was examined using multivariable Cox proportional-hazards regression, area under the receiver operating characteristic curve, and net reclassification improvement. The primary end point was a composite cardiovascular end point (CEP), defined as fatal or nonfatal stroke, death from coronary heart disease or nonfatal myocardial infarction. The positive association between age and systolic BP was more pronounced among individuals ≥50 years while the same was true for diastolic BP in those <50 years ( P interaction <0.001). Higher systolic BP and mean BP were significantly associated with cardiovascular end point, irrespective of age group ( P <0.001), but diastolic BP only demonstrated an independent relationship in the younger group ( P <0.001). Brachial pulse pressure was associated with cardiovascular end point in the older age group ( P <0.001). In subjects <50 years, diastolic BP significantly improved area under the receiver operating characteristic curve compared with Systematic Coronary Risk Evaluation variables (including systolic BP) alone (0.842 versus 0.840, P =0.03), enhanced continuous net reclassification improvement (0.150 [95% CI, 0.087–0.215]) and improved the prognostic value of the European Society of Cardiology/European Society of Hypertension hypertension definition (categorical net reclassification improvement=0.0255, P =0.005). In conclusion, diastolic BP may provide additional prognostic utility beyond systolic BP, in predicting composite cardiovascular events among younger individuals