Description: Background Prior studies have reported conflicting findings with regard to the association of biomarkers in the prediction of incident type 2 diabetes. We evaluated 12 biomarkers as possible diabetes predictors in the Framingham Heart Study. Methods and Results Biomarkers representing inflammation (C-reactive protein, interleukin-6, monocyte chemoattractant protein-1, tumor necrosis factor receptor 2, osteoprotegerin, and fibrinogen), endothelial dysfunction (intercellular adhesion molecule-1), vascular damage (CD40-ligand, P-selectin, and lipoprotein-associated phospholipase A2 mass and activity), and oxidative stress (urinary isoprostanes) were measured in participants without diabetes attending the Offspring seventh (n=2499) or multiethnic Omni second (n=189) examination (1998–2001). Biomarkers were log e transformed and standardized. Multivariable logistic regression tested each biomarker in association with incident diabetes at a follow-up examination (the Offspring eighth and Omni third examination; mean 6.6 years later), with adjustment for age, sex, cohort, body mass index, fasting glucose, systolic blood pressure, high-density lipoprotein cholesterol, triglycerides, and smoking. C statistics were evaluated with and without inflammatory markers. In 2638 participants (56% women, mean age 59 years), 162 (6.1%) developed type 2 diabetes. All biomarkers, excluding osteoprotegerin, were associated with the outcome with adjustment for age, sex, and cohort; however, none remained significant after multivariable adjustment (all P 〉0.05). The c statistic from the model including only clinical covariates (0.89) did not statistically significantly improve after addition of biomarkers (all P 〉0.10). Conclusions Biomarkers representing different inflammatory pathways are associated with incident diabetes but do not remain statistically significant after adjustment for established clinical covariates. Inflammatory biomarkers might not be an effective resource to predict type 2 diabetes in community-based samples.

Description: Rationale: Infusions of apolipoprotein AI (apoAI), mimetic peptides, or high-density lipoprotein (HDL) remain a promising approach for the treatment of atherosclerotic coronary disease. However, rapid clearance leads to a requirement for repeated administration of large amounts of material and limits effective plasma concentrations. Objective: Because pegylation of purified proteins is commonly used as a method to increase their half-life in the circulation, we determined whether pegylation of apoAI or HDL would increase its plasma half-life and in turn its antiatherogenic potential. Methods and Results: Initial pegylation attempts using lipid-poor apoAI showed a marked tendency to form multi-pegylated (PEG) species with reduced ability to promote cholesterol efflux from macrophage foam cells. However, pegylation of human holo-HDL or reconstituted phospholipid/apoAI particles (rHDL) led to selective N-terminal monopegylation of apoAI with full preservation of cholesterol efflux activity. The plasma clearance of PEG-rHDL was estimated after injection into hypercholesterolemic Apoe –/– mice; the half-life of pegylated PEG-apoAI after injection of PEG-rHDL was increased 7-fold compared with apoAI in nonpegylated rHDL. In comparison with nonpegylated rHDL, infusion of PEG-rHDL (40 mg/kg) into hypercholesterolemic Apoe –/– mice led to more pronounced suppression of bone marrow myeloid progenitor cell proliferation and monocytosis, as well as reduced atherosclerosis and a stable plaque phenotype. Conclusions: We describe a novel method for effective monopegylation of apoAI in HDL particles, in which lipid binding seems to protect against pegylation of key functional residues. Pegylation of apoAI in rHDL markedly increases its plasma half-life and enhances antiatherogenic properties in vivo.

Description: Rationale: Plasma high-density lipoprotein levels are inversely correlated with atherosclerosis. Although it is widely assumed that this is attributable to the ability of high-density lipoprotein to promote cholesterol efflux from macrophage foam cells, direct experimental support for this hypothesis is lacking. Objective: To assess the role of macrophage cholesterol efflux pathways in atherogenesis. Methods and Results: We developed mice with efficient deletion of the ATP-binding cassette transporters A1 and G1 (ABCA1 and ABCG1) in macrophages (MAC-ABC DKO mice) but not in hematopoietic stem or progenitor populations. MAC-ABC DKO bone marrow (BM) was transplanted into Ldlr –/– recipients. On the chow diet, these mice had similar plasma cholesterol and blood monocyte levels but increased atherosclerosis compared with controls. On the Western-type diet, MAC-ABC DKO BM–transplanted Ldlr –/– mice had disproportionate atherosclerosis, considering they also had lower very low-density lipoprotein/low-density lipoprotein cholesterol levels than controls. ABCA1/G1-deficient macrophages in lesions showed increased inflammatory gene expression. Unexpectedly, Western-type diet–fed MAC-ABC DKO BM–transplanted Ldlr –/– mice displayed monocytosis and neutrophilia in the absence of hematopoietic stem and multipotential progenitor cells proliferation. Mechanistic studies revealed increased expressions of machrophage colony stimulating factor and granulocyte colony stimulating factor in splenic macrophage foam cells, driving BM monocyte and neutrophil production. Conclusions: These studies show that macrophage deficiency of ABCA1/G1 is proatherogenic likely by promoting plaque inflammation and uncover a novel positive feedback loop in which cholesterol-laden splenic macrophages signal BM progenitors to produce monocytes, with suppression by macrophage cholesterol efflux pathways.

Description: Objective— Controversies have arisen from recent mouse studies about the essential role of biliary sterol secretion in reverse cholesterol transport (RCT). The objective of this study was to examine the role of biliary cholesterol secretion in modulating macrophage RCT in Niemann-Pick C1-Like 1 (NPC1L1) liver only (L1 LivOnly ) mice, an animal model that is defective in both biliary sterol secretion and intestinal sterol absorption, and determine whether NPC1L1 inhibitor ezetimibe facilitates macrophage RCT by inhibiting hepatic NPC1L1. Approach and Results— L1 LivOnly mice were generated by crossing NPC1L1 knockout (L1-KO) mice with transgenic mice overexpressing human NPC1L1 specifically in liver. Macrophage-to-feces RCT was assayed in L1-KO and L1 LivOnly mice injected intraperitoneally with [ 3 H]-cholesterol–labeled peritoneal macrophages isolated from C57BL/6 mice. Inhibition of biliary sterol secretion by hepatic overexpression of NPC1L1 substantially reduced transport of [ 3 H]-cholesterol from primary peritoneal macrophages to the neutral sterol fraction in bile and feces in L1 LivOnly mice without affecting tracer excretion in the bile acid fraction. Ezetimibe treatment for 2 weeks completely restored both biliary and fecal excretion of [ 3 H]-tracer in the neutral sterol fraction in L1 LivOnly mice. High-density lipoprotein kinetic studies showed that L1 LivOnly mice compared with L1-KO mice had a significantly reduced fractional catabolic rate without altered hepatic and intestinal uptake of high-density lipoprotein–cholesterol ether. Conclusions— In mice lacking intestinal cholesterol absorption, macrophage-to-feces RCT depends on efficient biliary sterol secretion, and ezetimibe promotes macrophage RCT by inhibiting hepatic NPC1L1 function.

Description: Objective— Patients with nonalcoholic fatty liver disease (NAFLD) have an increased risk of cardiovascular disease; however, it is not known whether NAFLD contributes to cardiovascular disease independent of established risk factors. We examined the association between NAFLD and vascular function. Approach and Results— We conducted a cross-sectional study of 2284 Framingham Heart Study participants without overt cardiovascular disease who had liver fat attenuation measured on computed tomography and who had measurements of vascular function and covariates. We evaluated the association between NAFLD and vascular function using multivariable partial correlations adjusting for age, sex, cohort, smoking, diabetes mellitus, hyperlipidemia, hypertension, body mass index, and visceral adipose tissue. The prevalence of NAFLD in our sample (mean age, 52±12 years; 51.4% women) was 15.3%. In age-, sex-, and cohort-adjusted analyses, greater liver fat was modestly associated with lower flow-mediated dilation ( r =–0.05; P =0.02), lower peripheral arterial tonometry ratio ( r =–0.20; P 〈0.0001), higher carotid-femoral pulse wave velocity ( r =0.13; P 〈0.0001), and higher mean arterial pressure ( r =0.11; P 〈0.0001). In multivariable-adjusted models, NAFLD remained associated with higher mean arterial pressure ( r =0.06; P =0.005) and lower peripheral arterial tonometry ratio ( r =–0.12; P 〈0.0001). The association between NAFLD and peripheral arterial tonometry ratio persisted after further adjustment for body mass index and visceral adipose tissue. Conclusions— For multiple measures of vascular function, the relationship with NAFLD appeared largely determined by shared cardiometabolic risk factors. The persistent relationship with reduced peripheral arterial tonometry response beyond established risk factors suggests that NAFLD may contribute to microvascular dysfunction.

Description: Background— Patients with severe left ventricular dysfunction, ischemic heart failure, and coronary artery disease suitable for coronary artery bypass grafting (CABG) are at higher risk for surgical morbidity and mortality. Paradoxically, those patients with the most severe coronary artery disease and ventricular dysfunction who derive the greatest clinical benefit from CABG are also at the greatest operative risk, which makes decision making regarding whether to proceed to surgery difficult in such patients. To better inform such decision making, we analyzed the Surgical Treatment for Ischemic Heart Failure (STICH) CABG population for detailed information on perioperative risk and outcomes. Methods and Results— In both STICH trials (hypotheses), 2136 patients with a left ventricular ejection fraction of ≤35% and coronary artery disease were allocated to medical therapy, CABG plus medical therapy, or CABG with surgical ventricular reconstruction. Relationships of baseline characteristics and operative conduct with morbidity and mortality at 30 days were evaluated. There were a total of 1460 patients randomized to and receiving surgery, and 346 (25%) of these high-risk patients developed a severe complication within 30 days. Worsening renal insufficiency, cardiac arrest with cardiopulmonary resuscitation, and ventricular arrhythmias were the most frequent complications and those most commonly associated with death. Mortality at 30 days was 5.1% and was generally preceded by a serious complication (65 of 74 deaths). Left ventricular size, renal dysfunction, advanced age, and atrial fibrillation/flutter were significant preoperative predictors of mortality within 30 days. Cardiopulmonary bypass time was the only independent surgical variable predictive of 30-day mortality. Conclusions— CABG can be performed with relatively low 30-day mortality in patients with left ventricular dysfunction. Serious postoperative complications occurred in nearly 1 in 4 patients and were associated with mortality. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00023595.

Description: Background Racial differences in electrocardiographic (ECG) characteristics and prognostic significance among Whites and Asians are not well described. Methods and Results We studied 2677 White Framingham Heart Study participants (57% women) and 2972 Asian (64% women) Singapore Longitudinal Aging Study participants (mean age 66 years in both) free of myocardial infarction or heart failure. Racial differences in ECG characteristics and effect on mortality were assessed. In linear regression models, PR interval was longer in Asians compared with Whites (multivariable-adjusted β±SE 5.0±1.4 ms in men and 6.6±0.9 ms in women, both P 〈0.0006). QT interval was shorter in Asian men (β±SE –6.2±1.2 ms, P 〈0.0001) and longer in Asian women (β±SE 3.6±0.9 ms, P =0.02) compared to White men and women, respectively. Asians had greater odds of having ECG left ventricular hypertrophy (LVH) compared with Whites (odds ratio [OR] 3.56, 95% confidence interval [CI] 1.36–9.35 for men, OR 1.93, 95% CI 1.35–2.76 for women, both P 〈0.02). Over a mean follow-up of 11±3 years in Framingham and 8±3 years in Singapore, mortality rates were 24.5 and 13.4 per 1000 person-years among Whites and Asians, respectively. In Cox models, the presence of LVH had a greater effect on all-cause mortality in Asians compared with Whites (hazard ratio [HR] 2.66, 95% CI 1.83–3.88 vs HR 1.30, 95% CI 0.90–1.89, P for interaction=0.02). Conclusion Our findings from two large community-based cohorts show prominent race differences in ECG characteristics between Whites and Asians, and also suggest a differential association with mortality. These differences may carry implications for race-specific ECG reference ranges and cardiovascular risk.

Description: The relations of measures of arterial stiffness, pulsatile hemodynamic load, and endothelial dysfunction to atrial fibrillation (AF) remain poorly understood. To better understand the pathophysiology of AF, we examined associations between noninvasive measures of vascular function and new-onset AF. The study sample included participants aged ≥45 years from the Framingham Heart Study offspring and third-generation cohorts. Using Cox proportional hazards regression models, we examined relations between incident AF and tonometry measures of arterial stiffness (carotid–femoral pulse wave velocity), wave reflection (augmentation index), pressure pulsatility (central pulse pressure), endothelial function (flow-mediated dilation), resting brachial arterial diameter, and hyperemic flow. AF developed in 407/5797 participants in the tonometry sample and 270/3921 participants in the endothelial function sample during follow-up (median 7.1 years, maximum 10 years). Higher augmentation index (hazard ratio, 1.16; 95% confidence interval, 1.02–1.32; P =0.02), baseline brachial artery diameter (hazard ratio, 1.20; 95% confidence interval, 1.01–1.43; P =0.04), and lower flow-mediated dilation (hazard ratio, 0.79; 95% confidence interval, 0.63–0.99; P =0.04) were associated with increased risk of incident AF. Central pulse pressure, when adjusted for age, sex, and hypertension (hazard ratio, 1.14; 95% confidence interval, 1.02–1.28; P =0.02) was associated with incident AF. Higher pulsatile load assessed by central pulse pressure and greater apparent wave reflection measured by augmentation index were associated with increased risk of incident AF. Vascular endothelial dysfunction may precede development of AF. These measures may be additional risk factors or markers of subclinical cardiovascular disease associated with increased risk of incident AF.