Subsequent Event Risk in Individuals With Established Coronary Heart Disease.

BACKGROUND: The Genetics of Subsequent Coronary Heart Disease (GENIUS-CHD) consortium was established to facilitate discovery and validation of genetic variants and biomarkers for risk of subsequent CHD events, in individuals with established CHD. METHODS: The consortium currently includes 57 studies from 18 countries, recruiting 185 614 participants with either acute coronary syndrome, stable CHD, or a mixture of both at baseline. All studies collected biological samples and followed-up study participants prospectively for subsequent events. RESULTS: Enrollment into the individual studies took place between 1985 to present day with a duration of follow-up ranging from 9 months to 15 years. Within each study, participants with CHD are predominantly of self-reported European descent (38%-100%), mostly male (44%-91%) with mean ages at recruitment ranging from 40 to 75 years. Initial feasibility analyses, using a federated analysis approach, yielded expected associations between age (hazard ratio, 1.15; 95% CI, 1.14-1.16) per 5-year increase, male sex (hazard ratio, 1.17; 95% CI, 1.13-1.21) and smoking (hazard ratio, 1.43; 95% CI, 1.35-1.51) with risk of subsequent CHD death or myocardial infarction and differing associations with other individual and composite cardiovascular endpoints. CONCLUSIONS: GENIUS-CHD is a global collaboration seeking to elucidate genetic and nongenetic determinants of subsequent event risk in individuals with established CHD, to improve residual risk prediction and identify novel drug targets for secondary prevention. Initial analyses demonstrate the feasibility and reliability of a federated analysis approach. The consortium now plans to initiate and test novel hypotheses as well as supporting replication and validation analyses for other investigators.

High Levels of (Un)Switched Memory B Cells Are Associated With Better Outcome in Patients With Advanced Atherosclerotic Disease.

BACKGROUND: Atherosclerosis is an inflammatory lipid disorder and the main underlying pathology of acute ischemic events. Despite a vast amount of data from murine atherosclerosis models, evidence of B-cell involvement in human atherosclerotic disease is limited. We therefore investigated the association of circulating B-cell subtypes with the occurrence of secondary cardiovascular events in advanced atherosclerotic disease. METHODS AND RESULTS: This cohort study consists of 168 patients who were included in the Athero-Express biobank between 2009 and 2011. Before surgery, peripheral blood mononuclear cells were isolated and stored in liquid nitrogen. After gentle thawing of the peripheral blood mononuclear cells, different B-cell subtypes including naïve, (un)switched memory, and CD27+CD43+ B1-like B cells, were analyzed by flow cytometry. Univariable and multivariable Cox proportional hazard models were used to analyze associations between B-cell subtypes, circulating antibodies and secondary cardiovascular manifestations during the 3-year follow-up period. Mean age was 70.1±9.6 years, males represented 62.8% of the population, and 54 patients had secondary manifestations during follow-up. High numbers of unswitched memory cells were protective against secondary outcome (hazard ratio, 0.30 [95% CI, 0.13-0.69]; P<0.01). Similar results were obtained for the switched memory cells that also showed to be protective against secondary outcome (hazard ratio, 0.33 [95% CI, 0.14-0.77]; P=0.01). CONCLUSIONS: A high number of (un)switched memory B cells is associated with better outcome following carotid artery endarterectomy. These findings suggest a potential role for B-cell subsets in prediction and prevention of secondary cardiovascular events in patients with atherosclerosis.

Radiation Awareness for Endovascular Abdominal Aortic Aneurysm Repair in the Hybrid Operating Room. An Instant Patient Risk Chart for Daily Practice.

PURPOSE: To determine which patient and C-arm characteristics are the strongest predictors of intraoperative patient radiation dose rates (DRs) during endovascular aneurysm repair (EVAR) procedures and create a patient risk chart. METHODS: A retrospective analysis was performed of 74 EVAR procedures, including 16,889 X-ray runs using fixed C-arm imaging equipment. Four multivariate log-linear mixed models (with patient as a random effect) were constructed. Mean air kerma DR (DRAK, mGy/s) and the mean dose area product DR (DRDAP, mGycm2/s) were the outcome variables utilized for fluoroscopy as differentiated from digital subtraction angiography (DSA). These models were used to predict the maximum radiation duration allowed before a 2-Gy skin threshold (for DRAK) or a 500-Gycm2 threshold (for DRDAP) was reached. RESULTS: The strongest predictor of DRAK and DRDAP for fluoroscopy imaging was the radiation protocol, with an increase of 200% when changing from "low" to "medium" and 410% from "low" to "normal." The strongest predictors of DRAK and DRDAP for DSA were C-arm angulation, with an increase of 47% per 30° of angulation, and body mass index (BMI), with an increase of 58% for every 5-point increase in BMI. Based on these models, a patient with a BMI of 30 kg/m2, combined with 45° of rotation and a field size of 800 cm2 in the medium fluoroscopy protocol has a predicted DRAK of 0.39 mGy/s (or 85.5 minutes until the 2-Gy skin threshold is reached). While using comparable settings but switching the acquisition to a DSA with a "2 frames per second" protocol, the predicted DRAK will be 6.6 mGy/s (or 5.0 minutes until the 2-Gy threshold is reached). CONCLUSION: X-ray radiation DRs are constantly fluctuating during and between patients based on BMI, the protocols, C-arm position, and the image acquisitions that are used. An instant patient risk chart visualizes these radiation dose fluctuations and provides an overview of the expected duration of X-ray radiation, which can be used to predict when follow-up dose thresholds are reached during abdominal endovascular procedures.

Extracellular Vesicle Proteins Associated with Systemic Vascular Events Correlate with Heart Failure: An Observational Study in a Dyspnoea Cohort.

BACKGROUND: SerpinF2, SerpinG1, CystatinC and CD14 are involved in inflammatory processes and plasma extracellular vesicle (EV) -levels of these proteins have been reported to be associated with systemic vascular events. Evidence is accumulating that inflammatory processes may play a pivotal role both in systemic vascular events and in heart failure. Therefore, we studied the association between plasma extracellular vesicle SerpinF2-, SerpinG1-, CystatinC and CD14-levels and the occurrence of acute heart failure in patients. METHODS AND RESULT: Extracellular vesicle protein levels of SerpinG1, SerpinF2, CystatinC and CD14 were measured in an observational study of 404 subjects presenting with dysponea at the emergency department (4B-cohort). Plasma extracellular vesicles were precipitated in a total extracellular vesicles (TEX)-fraction and in separate LDL- and HDL-subfractions. Extracellular vesicle protein levels were measured with a quantitative immune assay in all 3 precipitates. Out of 404 subjects, 141 (35%) were diagnosed with acutely decompensated heart failure. After correction for confounders (including comorbidities and medications), levels of CD14 in the HDL-fraction (OR 1.53, p = 0.01), SerpinF2 in the TEX-and LDL-fraction (ORs respectively 0.71 and 0.65, p<0.05) and SerpinG1 in the TEX-fraction (OR 1.55, p = 0.004) were statistically significantly related to heart failure. Furthermore, extracellular vesicle CD14- and SerpinF2-levels were significantly higher in heart failure patients with preserved ejection fraction than in those with reduced ejection fraction. CONCLUSION: Extracellular vesicle levels of CD14, SerpinG1 and SerpinF2 are associated with the occurrence of heart failure in subjects suspected for acute heart failure, suggesting common underlying pathophysiological mechanisms for heart failure and vascular events.

AlluraClarity Radiation Dose-Reduction Technology in the Hybrid Operating Room During Endovascular Aneurysm Repair.

PURPOSE: To evaluate the effect of radiation dose reduction with the Allura ClarityIQ image processing technology for fixed C-arms in comparison with a mobile C-arm and an Allura fixed C-arm without ClarityIQ technology during endovascular aneurysm repair (EVAR) procedures. METHODS: Radiation dose data from 85 patients (mean age 74.2±7.8 years; 68 men) undergoing EVAR with mobile and fixed C-arm fluoroscopy were retrospectively analyzed. The radiation dose parameters included the kerma area product (KAP), fluoroscopic time (FT), and number of digital subtraction angiography (DSA) frames (FrDSA). KAPtotal consisted of KAPfluoro (KAP for fluoroscopic imaging) and KAPDSA (KAP for DSA and single shots). Linear regression analysis was used to explore differences in the association of KAP with the FT, FrDSA, and body mass index (BMI) among the 3 C-arms. RESULTS: The mean KAPtotal values for mobile, Allura C-arm, and AlluraClarity C-arm for noncomplex EVARs were 56±39, 245±142, and 157±120 Gy·cm(2) (p<0.001); for complex EVARs, the values were 110±43, 874±653, and 598±319 Gy·cm(2) (p<0.001), respectively. On average, KAPfluoro tripled when the mobile C-arm was replaced by the fixed C-arm. There were no significant differences in the KAPfluoro adjusted for the FT between Allura and AlluraClarity (p=0.69). However, there was a major 61% reduction in KAPDSA from 1.36 Gy·cm(2) per DSA frame for Allura to 0.54 Gy·cm(2) per DSA frame with AlluraClarity (p=0.03). For the mobile C-arm, BMI was not associated with KAP (p=0.13). The associations of BMI with KAPfluoro and KAPDSA were significant for both fixed C-arms but were more robust for Allura compared to AlluraClarity (p=0.02 for KAPfluoro and p<0.001 for KAPDSA). CONCLUSION: Changing a mobile C-arm for a fixed C-arm in a hybrid operating suite increased the average intraoperative dose during EVAR. Upgrading the Allura fixed C-arm with ClarityIQ technology resulted in a 61% reduction in the radiation per DSA frame.

Routinely analyzed leukocyte characteristics improve prediction of mortality after coronary angiography.

BACKGROUND: Inflammation and leukocyte infiltration are hallmarks of atherosclerosis. Clinically routine hematology analyzers mostly perform an entire differential blood count by default, irrespective of the requested parameter. We hypothesize that these normally unreported leukocyte characteristics associate with coronary artery disease (CAD) severity and can improve prediction of mortality in coronary angiography patients. METHODS: We studied coronary angiography patients suspected of CAD (n = 1015) from the Utrecht Coronary Biobank cohort. Leukocyte characteristics were routinely assessed in blood drawn directly prior to angiography using an automated hematology analyzer and extracted from the Utrecht patient oriented database (UPOD) database. Patients were followed up for a median duration of 805 days, during which 65 patients died. We evaluated the association of leukocyte characteristics with synergy between PCI with taxus and cardiac surgery (SYNTAX) score as a measure of CAD severity, all-cause and cardiovascular mortality and major adverse cardiovascular events (MACEs). In order to determine the improvement of risk prediction, we calculated continuous net reclassification improvement (cNRI) and integrated discrimination improvement (IDI). RESULTS: Monocyte percentage showed strong independent predictive value for all-cause mortality (hazard ratio (HR) 1.44 (1.19-1.74), p < 0.001), and the monocyte-to-lymphocyte ratio performed best for cardiovascular mortality (HR 1.42 (1.11-1.81), p = 0.005). The cNRIs and IDIs of leukocyte characteristics for all-cause mortality confirmed the improvement in mortality risk prediction. No significantly predictive leukocyte characteristics were found for MACEs. CONCLUSION: Readily available yet unreported leukocyte characteristics from routine hematology analyzers significantly improved prediction of mortality in coronary angiography patients on top of clinical characteristics.

Inter-Ethnic Differences in Quantified Coronary Artery Disease Severity and All-Cause Mortality among Dutch and Singaporean Percutaneous Coronary Intervention Patients.

BACKGROUND: Coronary artery disease (CAD) is a global problem with increasing incidence in Asia. Prior studies reported inter-ethnic differences in the prevalence of CAD rather than the severity of CAD. The angiographic "synergy between percutaneous coronary intervention (PCI) with taxus and cardiac surgery" (SYNTAX) score quantifies CAD severity and predicts outcomes. We studied CAD severity and all-cause mortality in four globally populous ethnic groups: Caucasians, Chinese, Indians and Malays. METHODS: We quantified SYNTAX scores of 1,000 multi-ethnic patients undergoing PCI in two tertiary hospitals in the Netherlands (Caucasians) and Singapore (Chinese, Indians and Malays). Within each ethnicity we studied 150 patients with stable CAD and 100 with ST-elevated myocardial infarction (STEMI). We made inter-ethnic comparisons of SYNTAX scores and all-cause mortality. RESULTS: Despite having a younger age (mean age Indians: 56.8 and Malays: 57.7 vs. Caucasians: 63.7 years), multivariable adjusted SYNTAX scores were significantly higher in Indians and Malays than Caucasians with stable CAD: 13.4 [11.9-14.9] and 13.4 [12.0-14.8] vs. 9.4 [8.1-10.8], p<0.001. Among STEMI patients, SYNTAX scores were highest in Chinese and Malays: 17.7 [15.9-19.5] and 18.8 [17.1-20.6] vs. 15.5 [13.5-17.4] and 12.7 [10.9-14.6] in Indians and Caucasians, p<0.001. Over a median follow-up of 709 days, 67 deaths (stable CAD: 37, STEMI: 30) occurred. Among STEMI patients, the SYNTAX score independently predicted all-cause mortality: HR 2.5 [1.7-3.8], p<0.001 for every 10-point increase. All-cause mortality was higher in Indian and Malay STEMI patients than Caucasians, independent of SYNTAX score (adjusted HR 7.2 [1.5-34.7], p=0.01 and 5.8 [1.2-27.2], p=0.02). CONCLUSION: Among stable CAD and STEMI patients requiring PCI, CAD is more severe in Indians and Malays than in Caucasians, despite having a younger age. Moreover, Indian and Malay STEMI patients had a greater adjusted risk of all-cause mortality than Caucasians, independent of SYNTAX score.

Race/Ethnic Differences in the Associations of the Framingham Risk Factors with Carotid IMT and Cardiovascular Events.

BACKGROUND: Clinical manifestations and outcomes of atherosclerotic disease differ between ethnic groups. In addition, the prevalence of risk factors is substantially different. Primary prevention programs are based on data derived from almost exclusively White people. We investigated how race/ethnic differences modify the associations of established risk factors with atherosclerosis and cardiovascular events. METHODS: We used data from an ongoing individual participant meta-analysis involving 17 population-based cohorts worldwide. We selected 60,211 participants without cardiovascular disease at baseline with available data on ethnicity (White, Black, Asian or Hispanic). We generated a multivariable linear regression model containing risk factors and ethnicity predicting mean common carotid intima-media thickness (CIMT) and a multivariable Cox regression model predicting myocardial infarction or stroke. For each risk factor we assessed how the association with the preclinical and clinical measures of cardiovascular atherosclerotic disease was affected by ethnicity. RESULTS: Ethnicity appeared to significantly modify the associations between risk factors and CIMT and cardiovascular events. The association between age and CIMT was weaker in Blacks and Hispanics. Systolic blood pressure associated more strongly with CIMT in Asians. HDL cholesterol and smoking associated less with CIMT in Blacks. Furthermore, the association of age and total cholesterol levels with the occurrence of cardiovascular events differed between Blacks and Whites. CONCLUSION: The magnitude of associations between risk factors and the presence of atherosclerotic disease differs between race/ethnic groups. These subtle, yet significant differences provide insight in the etiology of cardiovascular disease among race/ethnic groups. These insights aid the race/ethnic-specific implementation of primary prevention.

Severity of stable coronary artery disease and its biomarkers differ between men and women undergoing angiography.

BACKGROUND: Coronary artery disease (CAD) affects both men and women. Cardiovascular biomarkers have been suggested to relate to CAD severity, but data on sex-specificity is scarce. Therefore, we investigated the association of established biomarkers with the severity of CAD in stable patients undergoing coronary angiography in a sex-specific manner. METHODS: We studied stable patients undergoing coronary angiography and measured CAD severity by SYNTAX score and biomarker levels (N-terminal pro-brain natriuretic peptide (NT pro-BNP), high-sensitivity CRP (hsCRP), cystatin C (CysC), myeloperoxidase (MPO), high-sensitivity troponin I (hsTnI) and von Willebrand factor (VWF)). We tested for sex differences in SYNergy between percutaneous coronary intervention with TAXUS™ and cardiac surgery (SYNTAX) scores and biomarker levels using multivariable ANCOVA. We investigated the association of biomarker levels with SYNTAX score in a multivariable linear regression with interaction terms for sex. RESULTS: We analysed data on 460 men and 175 women. SYNTAX scores were significantly lower in women (9.99 points vs. 11.88 points). Univariably, hsCRP and hsTnI levels were significantly associated with SYNTAX scores (both ß 2.5). In multivariable analysis only hsCRP associated with SYNTAX score (ß 1.9, p = 0.009). Sex did not modify the association of biomarkers with SYNTAX score. CONCLUSION: CAD severity as quantified by SYNTAX score is lower in women than men based on coronary angiography. The association of biomarkers with CAD severity did not differ between the sexes.