Clot Retraction and Its Correlation with the Function of Platelet Integrin αIIbß3.

Clot retraction results from retractions of platelet filopodia and fibrin fibers and requires the functional platelet αIIbß3 integrin. This assay is widely used to test the functions of platelets and fibrinogen as well as the efficacy of fibrinolysis. Changes in clot retraction have been found in a variety of hemostatic abnormalities and, more recently, in arterial thrombosis. Despite its broad clinical use and low cost, many aspects of clot retraction are poorly understood. In the present study, we performed two clinical standard clot retraction assays using whole-blood and platelet-rich plasma (PRP) samples to determine how clot retraction correlates with platelet counts and mean volume, the density of αIIbß3 integrin and PLA genotypes, and plasma fibrinogen levels. We found that clot retraction was affected by platelet counts, but not mean platelet volume. It correlated with the surface density of the integrin αIibß3, but not PLA genotypes. These results indicate that clot retraction measures a unique aspect of platelet function and can serve as an additional means to detect functional changes in platelets.

Age-Related Differences in the Contribution of Systolic Blood Pressure and Biomarkers to Cardiovascular Disease Risk Prediction: The Atherosclerosis Risk in Communities (ARIC) Study.

We sought to determine how biomarkers known to be associated with hypertension-induced end-organ injury complement the use of systolic blood pressure (SBP) for cardiovascular disease (CVD) risk prediction at different ages. Using data from visits 2 (1990 to 1992) and 5 (2011 to 2013) of the Atherosclerosis Risk in Communities (ARIC) study, 3 models were used to predict CVD (composite of coronary heart disease, stroke, and heart failure). Model A included traditional risk factors (TRFs) except SBP, model B-TRF plus SBP, and model C-TRF plus biomarkers (high-sensitivity troponin T [hsTnT] and N-terminal pro-B-type natriuretic peptide [NT-proBNP]). Harrel's C-statistics were used to assess risk discrimination for CVD comparing models B and A and C and B. At visit 2, the addition of SBP to TRF (model B vs model A) significantly improved the C-statistic (∆C-statistic, 95% confidence interval 0.010, 0.007 to 0.013) whereas the addition of hsTnT to TRF (model C vs model B) decreased the C-statistic (∆C-statistic -0.0038, -0.0075 to -0.0001) compared with SBP. At visit 5, the addition of SBP to TRF did not significantly improve the C-statistic (∆C-statistic 0.001, -0.002 to 0.005) whereas the addition of both hsTnT and NT-proBNP to TRF significantly improved the C-statistic compared with SBP (∆C-statistic 0.028, 0.015 to 0.041 and 0.055, 0.036 to 0.074, respectively). In summary, the incremental value of SBP for CVD risk prediction diminishes with age whereas the incremental value of hsTnT and NT-proBNP increases with age.

Association of interleukin-6 and interleukin-18 with cardiovascular disease in older adults: Atherosclerosis Risk in Communities study.

AIMS: Interleukin-6 (IL-6) and interleukin-18 (IL-18), important cytokines implicated in atherosclerosis and inflammaging, were assessed for associations with global cardiovascular disease (CVD), atrial fibrillation (AF), and death in older adults. METHODS AND RESULTS: Participants from Atherosclerosis Risk in Communities study Visit 5 (mean age 75.4 ± 5.1 years) with IL-6 and IL-18 measurements were included (n = 5672). Cox regression models were used to assess associations of IL-6 and IL-18 with coronary heart disease (CHD), ischaemic stroke, heart failure (HF) hospitalization, global CVD (composite of CHD, stroke, and HF), AF, and all-cause death. Over a median follow-up of 7.2 years, there were 1235 global CVD events, 530 AF events, and 1173 deaths. Higher IL-6 [hazard ratio (HR) 1.57, 95% confidence interval (CI) 1.44-1.72 per log unit increase] and IL-18 (HR 1.13, 95% CI 1.01-1.26) were significantly associated with global CVD after adjustment for cardiovascular risk factors. Association between IL-6 and global CVD remained significant after further adjustment for high-sensitivity C-reactive protein (hs-CRP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and high-sensitivity troponin T (hs-TnT) but was no longer significant for IL-18 after further adjustments. Interleukin-6 was also associated with increased risk for CHD, HF, and AF after adjustment for covariates. Both IL-6 and IL-18 were associated with increased risk for all-cause death independent of cardiovascular risk factors and other biomarkers. CONCLUSION: Among older adults, both IL-6 and IL-18 were associated with global CVD and death. The association between IL-6 with CVD appears to be more robust and was independent of hs-CRP, NT-proBNP, and hs-TnT.

In older adults in the Atherosclerosis Risk in Communities study (average age 75 years), higher levels of interleukin-6 and interleukin-18, two proteins implicated in atherosclerosis and increased inflammation that occurs with ageing, significantly increased risk for global cardiovascular disease (including coronary heart disease, stroke, and heart failure) during the next ∼7 years; interleukin-6 also increased risk for global cardiovascular disease, coronary heart disease, heart failure, and atrial fibrillation even after adjustment for other biomarkers of inflammation and subclinical myocardial injury, and both interleukin-6 and interleukin-18 were associated with increased risk for all-cause death independent of cardiovascular risk factors and other biomarkers. In older adults, higher levels of interleukin-6 and interleukin-18 were both associated with increased risk for global cardiovascular disease (including coronary heart disease, stroke, and heart failure) and death.The association between interleukin-6 and global cardiovascular disease appeared to be stronger than that for interleukin-18 and remained significant after adjustment for other biomarkers of inflammation and subclinical myocardial injury.

Temporal Trends in Lipoprotein(a) Concentrations: The Atherosclerosis Risk in Communities Study.

Background Plasma lipoprotein(a) (Lp[a]) concentrations are primarily determined by genetic factors and are believed to remain stable throughout life. However, data are scarce on longitudinal trends in Lp(a) concentrations over time. Therefore, it is unclear whether measurement of Lp(a) once in a person's life is sufficient for cardiovascular risk assessment in all adults. Methods and Results Lp(a) concentrations, specifically apolipoprotein(a) concentrations, were measured at visits 4 and 5, ≈15 years apart, in 4734 adult participants of the ARIC (Atherosclerosis Risk in Communities) study (mean age at visits 4 and 5, 60.7±5.1 and 75.5±5.2 years, respectively). Participants were categorized by baseline (visit 4) Lp(a) concentrations as normal (<30 mg/dL), borderline-high (30-49 mg/dL), or high (≥50 mg/dL). We compared adults with Lp(a) change ≥20 mg/dL between visits and those with Lp(a) change <20 mg/dL. Multivariable logistic regression analysis was used to identify covariates associated with change in Lp(a) over time. At visit 5, 58.1% of participants with borderline-high Lp(a) concentrations of 30 to 49 mg/dL at visit 4 had high Lp(a) concentrations ≥50 mg/dL. Participants with low Lp(a) (<30 mg/dL) or high Lp(a) (≥50 mg/dL) at visit 4 tended to stay in these respective categories. Black race, female sex, diabetes, hypertension, total cholesterol, and albuminuria were associated with significantly greater probability for Lp(a) change ≥20 mg/dL over time. Conclusions Our results suggest that adults with borderline-high Lp(a) concentrations may be considered for repeat monitoring of Lp(a) over time, particularly if they are Black, women, or have diabetes, hypertension, and/or elevated albuminuria.

Midlife determinants of healthy cardiovascular aging: The Atherosclerosis Risk in Communities (ARIC) study.

BACKGROUND AND AIMS: Risk factor cutoffs are derived from associations with clinical cardiovascular disease (CVD), but how these risk factors associate with preserved cardiovascular health into old age is not well studied. We investigated midlife determinants of healthy versus nonhealthy cardiovascular aging in the Atherosclerosis Risk in Communities (ARIC) study. METHODS: ARIC participants were categorized by cardiovascular status in older age (mean age 75.8 ± 5.3 years, range 66-90): healthy, subclinical disease (assessed by biomarkers and left ventricular function), clinical CVD (coronary heart disease, stroke, or heart failure), or prior death. We examined associations of midlife (mean age 52.1 ± 5.1 years) systolic and diastolic blood pressure (SBP, DBP), low-density lipoprotein cholesterol (LDL-C), triglycerides, hemoglobin A1c (HbA1c), and body mass index (BMI) with cardiovascular status in older age using multinomial logistic regression analyses. RESULTS: Compared with healthy status, odds for subclinical disease (odds ratio [OR] 1.30, 95% confidence interval [CI] 1.09-1.55) and clinical CVD (OR 1.87, 95% CI 1.53-2.29) at older age increased starting with midlife SBP 120-129 mmHg, whereas odds for death increased starting with SBP 110-119 mmHg (OR 1.29, 95% CI 1.10-1.52); findings were similar for DBP. Odds for subclinical disease increased for HbA1c ≥ 6.5% and BMI starting at 30-<35 kg/m2; odds for clinical CVD or death increased starting at HbA1c 5.5-5.9%, LDL-C >160 mg/dL, and BMI 30-<35 kg/m2. CONCLUSIONS: More-stringent levels of modifiable risk factors in midlife beyond current clinical practice and guidelines were associated with preserved cardiovascular health in older age.

Triglyceride-rich lipoproteins, apolipoprotein C-III, angiopoietin-like protein 3, and cardiovascular events in older adults: Atherosclerosis Risk in Communities (ARIC) study.

AIMS: Despite statin and antihypertensive therapies, older Americans have high atherosclerotic cardiovascular disease (ASCVD) risk. Novel measures of triglyceride-rich lipoproteins, low-density lipoprotein triglycerides (LDL-TG), and remnant-like particle cholesterol (RLP-C), are associated with ASCVD in middle-aged adults. Polymorphisms in genes encoding angiopoietin-related protein 3 (ANGPTL3) and apolipoprotein C-III (apoC-III), two proteins involved in triglyceride catabolism, are associated with increased risk for hypertriglyceridaemia and ASCVD and are potential therapeutic targets. We examined associations of LDL-TG, RLP-C, apoC-III, and ANGPTL3 levels with ASCVD events in older adults in the Atherosclerosis Risk in Communities (ARIC) study. METHODS AND RESULTS: In 6359 participants (mean age 75.8 ± 5.3 years) followed for ASCVD events [coronary heart disease (CHD) or ischaemic stroke] up to 6 years, associations between LDL-TG, RLP-C, apoC-III, and ANGPTL3 and ASCVD events were assessed using Cox regression. With adjustment for age, sex, and race, RLP-C, LDL-TG, apoC-III, and ANGPTL3 (as continuous variables) were significantly associated with CHD. However, after adjustment for traditional risk factors and lipid-lowering medications, only LDL-TG and ANGPTL3 were significantly associated with ASCVD events [hazard ratio (HR) 1.72, 95% confidence interval (CI) 1.25-2.37 per log unit increase in LDL-TG; HR 1.63, 95% CI 1.17-2.28 per log unit increase in ANGPTL3]. CONCLUSIONS: In older adults, LDL-TG, RLP-C, apoC-III, and ANGPTL3 were associated with CHD events in minimally adjusted models; LDL-TG and ANGPTL3 remained independent predictors of ASCVD events with further adjustment. Future studies should assess potential benefit of lowering hepatic apoC-III or ANGPTL3 expression in patients with elevated triglyceride-rich lipoproteins.

The Use of Continuous Glucose Monitoring in Older People With Type 2 Diabetes.

Objective To review current guidelines and literature regarding continuous glucose monitoring (CGM) use in the management of type 2 diabetes mellitus (T2DM) in older people. Data Sources A PubMed search of articles published through August 2020 using a combination of the following: older people, T2DM, continuous glucose monitoring, hypoglycemia, and hyperglycemia. Study Selection/Data Extraction Relevant randomized control trials, meta-analyses, and guidelines were assessed for the use of CGM in older patients with T2DM. Articles were included based on relevance to the topic, detailed methods, and complete results. Data Synthesis CGM use in T2DM management in older people is not well defined. CGM may be a valuable technology in older people who face unique challenges, such as hypoglycemia, decline in cognitive function, and variable glucose levels. This article provides a review of recommendations for glucose monitoring in T2DM and discusses the role of specific CGM products. Conclusion CGM is a viable option for older people with T2DM to help improve overall diabetes control. Pharmacists can play an important role in educating patients about this technology.

Association between circulating Galectin-3 and arterial stiffness in older adults.

Background: Galectin-3 (gal-3) is a ß-galactoside-binding lectin associated tissue fibrosis and inflammation. There is limited understanding of the relationship between gal-3 and vascular health. Our aim was to assess the association between gal-3 and arterial stiffness in older adults. Methods: We conducted a cross-sectional study of 4275 participants (mean age of 75 years) from the Atherosclerosis Risk in Communities (ARIC) Study. Central arterial stiffness was measured by carotid-femoral pulse wave velocity (cfPWV). We evaluated the association of gal-3 with cfPWV using multivariable linear regression. Results: The median (interquartile range) gal-3 concentration was 16.5 (13.8, 19.8) ng/mL and mean cfPWV was 1163±303 cm/s. Higher gal-3 concentration was associated with greater central arterial stiffness after adjustment for age, sex, race-center, heart rate, systolic blood pressure, anti-hypertensive medication use, and current smoking status (ß=36.4 cm/s change in cfPWV per log unit change in gal-3; 95% CI: 7.2, 65.5, p=0.015). The association was attenuated after adjusting for additional cardiovascular risk factors (ß=17.3, 95% CI: -14.4, 49.0). Conclusions: In community-dwelling older adults, gal-3 concentration was associated with central arterial stiffness, likely sharing common pathways with traditional cardiovascular risk factors.

Soluble Angiotensin-Converting Enzyme 2, Cardiac Biomarkers, Structure, and Function, and Cardiovascular Events (from the Atherosclerosis Risk in Communities Study).

Membrane-bound angiotensin-converting enzyme 2 is important in regulation of the renin-angiotensin-aldosterone system, but the association of cleaved soluble ACE2 (sACE2) with cardiovascular disease (CVD) is unclear. We evaluated the association of sACE2 with cardiac biomarkers, structure, and function and cardiovascular events in the Atherosclerosis Risk in Communities Study. sACE2 was measured in a subset of 497 participants (mean age 78±5.4 years, 53% men, 27% black); Cox regression analyses assessed prospective associations of sACE2 with time to first CVD event at median 6.1-year follow-up. sACE2 was higher in men, blacks, and participants with prevalent CVD, diabetes, or hypertension. Higher sACE2 levels were associated with significantly higher biomarkers of cardiac injury (high-sensitivity cardiac troponin I and T, N-terminal pro-B-type natriuretic peptide), greater left ventricular mass index, and impaired diastolic function in linear regression analyses, and with increased risk for heart failure hospitalization (adjusted hazard ratio per natural log unit increase [HR] 1.32, 95% confidence interval [CI] 1.10 to 1.58), CVD events (HR 1.34, 95% CI 1.13 to 1.60), and all-cause death (HR 1.26, 95% CI 1.01 to 1.57). In an elderly biracial cohort, sACE2 was positively associated with biomarkers reflecting myocardial injury and neurohormonal activation, left ventricular mass index, impaired diastolic function, CVD, events and all-cause death.

Association of Circulating Monocyte Chemoattractant Protein-1 Levels With Cardiovascular Mortality: A Meta-analysis of Population-Based Studies.

Importance: Human genetics and studies in experimental models support a key role of monocyte-chemoattractant protein-1 (MCP-1) in atherosclerosis. Yet, the associations of circulating MCP-1 levels with risk of coronary heart disease and cardiovascular death in the general population remain largely unexplored. Objective: To explore whether circulating levels of MCP-1 are associated with risk of incident coronary heart disease, myocardial infarction, and cardiovascular mortality in the general population. Data Sources and Selection: Population-based cohort studies, identified through a systematic review, that have examined associations of circulating MCP-1 levels with cardiovascular end points. Data Extraction and Synthesis: Using a prespecified harmonized analysis plan, study-specific summary data were obtained from Cox regression models after excluding individuals with overt cardiovascular disease at baseline. Derived hazard ratios (HRs) were synthesized using random-effects meta-analyses. Main Outcomes and Measures: Incident coronary heart disease (myocardial infarction, coronary revascularization, and unstable angina), nonfatal myocardial infarction, and cardiovascular death (from cardiac or cerebrovascular causes). Results: The meta-analysis included 7 cohort studies involving 21 401 individuals (mean [SD] age, 53.7 [10.2] years; 10 012 men [46.8%]). Mean (SD) follow-up was 15.3 (4.5) years (326 392 person-years at risk). In models adjusting for age, sex, and race/ethnicity, higher MCP-1 levels at baseline were associated with increased risk of coronary heart disease (HR per 1-SD increment in MCP-1 levels: 1.06 [95% CI, 1.01-1.11]; P = .01), nonfatal myocardial infarction (HR, 1.07 [95% CI, 1.01-1.13]; P = .02), and cardiovascular death (HR, 1.12 [95% CI, 1.05-1.20]; P < .001). In analyses comparing MCP-1 quartiles, these associations followed dose-response patterns. After additionally adjusting for vascular risk factors, the risk estimates were attenuated, but the associations of MCP-1 levels with cardiovascular death remained statistically significant, as did the association of MCP-1 levels in the upper quartile with coronary heart disease. There was no significant heterogeneity; the results did not change in sensitivity analyses excluding events occurring in the first 5 years after MCP-1 measurement, and the risk estimates were stable after additional adjustments for circulating levels of interleukin-6 and high-sensitivity C-reactive protein. Conclusions and Relevance: Higher circulating MCP-1 levels are associated with higher long-term cardiovascular mortality in community-dwelling individuals free of overt cardiovascular disease. These findings provide further support for a key role of MCP-1-signaling in cardiovascular disease.

Plasma Dehydroepiandrosterone Sulfate and Cardiovascular Disease Risk in Older Men and Women.

CONTEXT: Lower dehydroepiandrosterone-sulfate (DHEA-S) levels have been inconsistently associated with coronary heart disease (CHD) and mortality. Data are limited for heart failure (HF) and association between DHEA-S change and events. OBJECTIVE: Assess associations between low DHEA-S/DHEA-S change and incident HF hospitalization, CHD, and mortality in older adults. DESIGN: DHEA-S was measured in stored plasma from visits 4 (1996-1998) and 5 (2011-2013) of the Atherosclerosis Risk in Communities study. Follow-up for incident events: 18 years for DHEA-S level; 5.5 years for DHEA-S change. SETTING: General community. PARTICIPANTS: Individuals without prevalent cardiovascular disease (n = 8143, mean age 63 years). MAIN OUTCOME MEASURE: Associations between DHEA-S and incident HF hospitalization, CHD, or mortality; associations between 15-year change in DHEA-S (n = 3706) and cardiovascular events. RESULTS: DHEA-S below the 15th sex-specific percentile of the study population (men: 55.4 µg/dL; women: 27.4 µg/dL) was associated with increased HF hospitalization (men: hazard ratio [HR] 1.30, 95% confidence interval [CI], 1.07-1.58; women: HR 1.42, 95% CI, 1.13-1.79); DHEA-S below the 25th sex-specific percentile (men: 70.0 µg/dL; women: 37.1 µg/dL) was associated with increased death (men: HR 1.12, 95% CI, 1.01-1.25; women: HR 1.19, 95% CI, 1.03-1.37). In men, but not women, greater percentage decrease in DHEA-S was associated with increased HF hospitalization (HR 1.94, 95% CI, 1.11-3.39). Low DHEA-S and change in DHEA-S were not associated with incident CHD. CONCLUSIONS: Low DHEA-S is associated with increased risk for HF and mortality but not CHD. Further investigation is warranted to evaluate mechanisms underlying these associations.

Levels and Change in Galectin-3 and Association With Cardiovascular Events: The ARIC Study.

Background Circulating galectin-3 levels provide prognostic information in patients with established heart failure (HF), but the associations between galectin-3 levels and other incident cardiovascular events in asymptomatic individuals at midlife and when remeasured ≈15 years later are largely uncharacterized. Methods and Results Using multivariable Cox proportional hazards models, we identified associations between plasma galectin-3 levels (hazard ratio [HR] per 1 SD increase in natural log galectin-3) and incident coronary heart disease, ischemic stroke, HF hospitalization, and total mortality in ARIC (Atherosclerosis Risk in Communities) participants free of cardiovascular disease at ARIC visit 4 (1996-1998; n=9247) and at ARIC visit 5 (2011-2013; n=4829). Higher galectin-3 level at visit 4 (median age 62) was independently associated with incident coronary heart disease (adjusted HR, 1.30; 95% CI, 1.06-1.60), ischemic stroke (HR, 1.42; 95% CI, 1.01-2.00), HF (HR, 1.44; 95% CI, 1.17-1.76), and mortality (HR, 1.56; 95% CI, 1.35-1.80). At visit 5 (median age, 74), higher galectin-3 level was associated with incident HF (HR, 1.93; 95% CI, 1.15-3.24) and total mortality (HR, 1.70; 95% CI, 1.15-2.52), but not coronary heart disease or stoke. Individuals with the greatest increase in galectin-3 levels from visit 4 to visit 5 were also at increased risk of incident HF and total mortality. Conclusions In a large, biracial community-based cohort, galectin-3 measured at midlife and older age was associated with increased risk of cardiovascular events. An increase in galectin-3 levels over this period was also associated with increased risk.