Evaluation of GSK2789917-induced TRPV4 inhibition in animal models of fluid induced lung injury

Administration of bolus intravenous fluids, common in pre-hospital and hospitalised patients, is associated with increased lung vascular permeability and mortality outside underlying disease states. In our laboratory, the induction of lung injury and oedema through rapid administration of intravenous fluid in rats was reduced by a non-specific antagonist of transient receptor potential vanilloid 4 (TRPV4) channels. The aims of this study were to determine the effect of selective TRPV4 inhibition on fluid-induced lung injury (FILI) and compare the potency of FILI inhibition to that of an established model of TRPV4 agonist-induced lung oedema. In a series of experiments, rats received specific TRPV4 inhibitor (GSK2789917) at high (15 μg/kg), medium (5 μg/kg) or low (2 μg/kg) dose or vehicle prior to induction of lung injury by intravenous infusion of TRPV4 agonist (GSK1016790) or saline. GSK1016790 significantly increased lung wet weight/body weight ratio by 96% and lung wet-to-dry weight ratio by 43% in vehicle pre-treated rats, which was inhibited by GSK2789917 in a dose-dependent manner (IC50 = 3 ng/mL). Similarly, in a single-dose study, bolus saline infusion significantly increased lung wet weight/body weight by 17% and lung wet-to-dry weight ratio by 15%, which was attenuated by high dose GSK2789917. However, in a final GSK2789917 dose-response study, inhibition did not reach significance and an inhibitory potency was not determined due to the lack of a clear dose-response. In the FILI model, TRPV4 may have a role in lung injury induced by rapid-fluid infusion, indicated by inconsistent amelioration with high dose TRPV4 antagonist.

Pazopanib for severe bleeding and transfusion-dependent anemia in hereditary hemorrhagic telangiectasia

Hereditary hemorrhagic telangiectasia (HHT) is a rare angiogenic disorder causing chronic gastrointestinal bleeding, epistaxis, and severe anemia. Pazopanib is an oral multi-kinase angiogenesis inhibitor with promise to treat bleeding in HHT. We analyzed outcomes of HHT patients with the most severe bleeding causing RBC transfusion dependence treated on a predefined institutional pazopanib treatment pathway (with data collected retrospectively). The primary endpoint was achievement of transfusion independence. Secondary endpoints included hemoglobin, epistaxis severity score, RBC transfusion and iron infusion requirements, number of local hemostatic procedures, ferritin and transferrin saturation, compared using paired and repeated measures mean tests. Thirteen transfusion-dependent HHT patients received pazopanib [median (range) dose 150 (25–300) mg daily)] for a median of 22 months. All patients achieved transfusion independence. Compared with pretreatment, pazopanib increased mean hemoglobin by 4.8 (95% CI, 3.6–5.9) g/dL (7.8 vs. 12.7 g/dL, P < 0.0001) and decreased mean epistaxis severity score by 4.77 (3.11–6.44) points (7.20 vs. 2.43 points, P < 0.0001) after 12 months of treatment. Compared with 3 months of pretreatment, RBC transfusions decreased by 93% (median of 16.0 vs. 0.0 units, P < 0.0001) and elemental iron infusion decreased by 92% (median of 4500 vs. 0 mg, P = 0.005) during the first 3 months of treatment; improvements were maintained over time. Pazopanib was well-tolerated: hypertension, lymphocytopenia, and fatigue were the most common TEAEs. In conclusion, pazopanib was safe and effective to manage severe bleeding in HHT, liberating all patients from transfusion dependence and normalizing hematologic parameters at doses lower than used to treat malignancies. These findings require confirmation in a randomized trial.

Identification of a Human Whole Blood-Based Endothelial Cell Impedance Assay for Assessing Clinical Transient Receptor Potential Vanilloid 4 Target Engagement Ex Vivo

Transient receptor potential vanilloid 4 (TRPV4) channels expressed on pulmonary endothelial cells are activated by elevated pulmonary vascular pressure, resulting in endothelial shape change, pulmonary barrier disruption, and edema. As such, TRPV4 blocker GSK2798745 was recently investigated in phase I/IIa trials to reduce pulmonary edema caused by heart failure (HF). In the absence of a suitable TRPV4 target engagement biomarker, we hypothesized that an ex vivo assay could be used to predict pharmacological activity at the intended site of action (endothelial cells) of subjects. In this assay, the ability of GSK2798745 to block TRPV4 agonist GSK1016790-induced impendence reduction in human umbilical vein endothelial cells (HUVECs) in the presence of human whole blood was assessed. Blood from healthy volunteers drawn 1-12 hours after single or repeated dose of GSK2798745 (5 mg) inhibited GSK1016790-induced impedance reduction by ≥85%. Similarly, blood samples from 16 subjects with HF dosed with GSK2798745 (2.4 mg) inhibited GSK1016790-induced HUVEC impedance reduction by ≥58% 1-24 hours after single dosing and ≥78% 1-24 hours after 7 days of repeated dosing. No inhibition was detected using blood from placebo subjects. Using matched GSK2798745 plasma levels, a pharmacokinetic/pharmacodynamic (PK/PD) relationship was calculated as 2.9 nM IC₅₀, consistent with the 6.5 nM IC₅₀ of GSK2798745 obtained from a rat in vivo PK/PD model of pulmonary edema after correcting for rat-to-human differences. These results indicate that circulating levels of GSK2798745 in the recently completed phase I/IIa trials were sufficient to block TRPV4 in lung vascular endothelial cells to a large extent, supporting this dosing regimen for assessing efficacy in HF. SIGNIFICANCE STATEMENT: In the absence of a suitable target engagement biomarker, we developed an ex vivo assay to predict the pharmacological activity of the transient receptor potential vanilloid 4 (TRPV4) blocker GSK2798745 in healthy volunteers and subjects with heart failure (HF) from phase I/IIa trials. The potency values from the ex vivo assay were consistent with those predicted from a rat in vivo pharmacokinetic/pharmacodynamic model of pulmonary edema, strongly suggesting that circulating levels of GSK2798745 were sufficient to robustly block TRPV4, supporting use of GSK2798745 for assessing efficacy in HF.

Assessing the Impact of Losmapimod on Proteinuria in Idiopathic Focal Segmental Glomerulosclerosis

Introduction

Idiopathic focal segmental glomerulosclerosis (FSGS) is a leading cause of nephrotic syndrome and end-stage renal disease. In preclinical models and biopsies of human FSGS kidneys, p38 mitogen-activated protein kinase (MAPK) has demonstrated enhanced activity; and p38 MAPK inhibition has improved disease markers. This proof-of-concept trial aimed to assess efficacy, safety, tolerability, and pharmacokinetics of losmapimod, an oral p38 MAPK inhibitor, in humans with FSGS.

Methods

A single-arm, multicenter, open-label, Phase II trial (NCT02000440) was conducted in adults with FSGS; proteinuria ≥2.0 g/d; estimated glomerular filtration rate (eGFR) ≥45 ml/min per 1.73 m²; blood pressure <140/90 mm Hg. Collapsing and genetic forms of FSGS were excluded. The primary endpoint was number of patients with ≥50% proteinuria reduction and eGFR ≥70% of baseline after receiving losmapimod twice-daily for 16 to 24 weeks.

Results

Seventeen patients received ≥1 losmapimod dose. No patients achieved the primary endpoint; therefore, the study was terminated following a prespecified interim analysis. At week 24, proteinuria reductions between 20% and <50% were observed in 4 patients and proteinuria increases >20% in 3 patients. One patient achieved a proteinuria response (≥50% reduction) at week 2 but subsequently relapsed. Losmapimod pharmacokinetics were consistent with prior studies. No serious adverse events (AEs) were reported.

Conclusion

p38 MAPK inhibition with losmapimod did not result in ≥50% reduction of proteinuria in patients with FSGS. However, study population heterogeneity may have contributed to our negative findings and therefore this does not eliminate the potential to demonstrate benefit in a population more sensitive to p38 MAPK inhibition if identifiable in the future by precision-medicine methods.

Targeting pulmonary capillary permeability to reduce lung congestion in heart failure: a randomized, controlled pilot trial

AIMS

Lung congestion in patients with heart failure (HF) has traditionally been treated using interventions that reduce pulmonary capillary hydrostatic pressure. The transient receptor potential vanilloid 4 (TRPV4) channel regulates fluid transit across the pulmonary capillary-interface, and represents a novel target to reduce lung water, independent of pulmonary capillary hypertension. This pilot study examined the safety and potential efficacy of TRPV4 blockade as a novel treatment for HF.

METHODS AND RESULTS

In this randomized, double-blind, placebo-controlled crossover pilot trial, 11 subjects with chronic, compensated HF were treated with a novel TRPV4 antagonist (GSK2798745) or placebo. The primary endpoint was lung diffusing capacity for carbon monoxide (DL_CO ) after 7 days of treatment with GSK2798745 as compared to placebo. Secondary endpoints included additional diffusion parameters, spirometry and safety assessments. Compared to placebo, treatment with GSK2798745 resulted in a trend to improvement in DL_CO (placebo: -0.336 mL/mmHg/min; GSK2798745: +0.458 mL/mmHg/min; treatment difference: +0.793 mL/mmHg/min; 95% confidence interval: -0.925 to 2.512) that was not statistically significant. GSK2798745 was well-tolerated with no serious adverse events.

CONCLUSION

In this pilot trial, GSK2798745 was found to be safe and well-tolerated, with a trend toward improved gas transfer. Further investigation is warranted in larger studies to determine whether treatment with TRPV4 antagonists or alternative treatments targeting capillary permeability might be effective to improve lung congestion, pulmonary gas transfer and clinical status in patients with acute or chronic HF.

The Burden of Congestion in Patients Hospitalized With Acute Decompensated Heart Failure

Congestion is associated with adverse outcomes in heart failure (HF) patients. We characterized congestion in patients hospitalized for HF and examined the association between congestion severity at admission and postdischarge outcomes. Using the OPTIMIZE-HF registry linked to Medicare claims, we analyzed patients ≥65 years old hospitalized for HF from 2003 to 2004. Congestion severity was measured using a 15-point scale that scores dyspnea, orthopnea, fatigue, jugular venous pressure, rales, and edema. Patient characteristics and outcomes were described by congestion strata. Proportional hazards models were fit to examine associations between congestion and 1-year outcomes. Congestion scores for the 24,724 patients ranged from 0 to 14, with a median of 5 (Q1, Q3: 3, 7). At baseline, patients with the highest scores (≥7) had the highest rates of recent HF hospitalizations, EF ≤40%, and co-morbidities, including arrhythmias, diabetes mellitus, and renal insufficiency. Adjusting for patient characteristics, a 3-point congestion score increase was positively associated with mortality (hazard ratio [HR] 1.06, 95% confidence interval [CI] 1.03, 1.09), all-cause rehospitalization (HR 1.02, 95% CI 1.00, 1.04), and HF rehospitalization (HR 1.09, 95% CI 1.06, 1.12), but not emergency department visits (HR 0.99, 95% CI 0.97, 1.01). In conclusion, for patients hospitalized with HF, congestion was associated with rehospitalization and mortality.

A Randomized, Placebo-Controlled Trial to Assess the Effects of 8 Weeks of Administration of GSK256073, a Selective GPR109A Agonist, on High-Density Lipoprotein Cholesterol in Subjects With Dyslipidemia

GPR109A (HM74A), a G-protein-coupled receptor, is hypothesized to mediate lipid and lipoprotein changes and dermal flushing associated with niacin administration. GSK256073 (8-chloro-3-pentyl-1H-purine-2,6[3H,7H]-dione) is a selective GPR109A agonist shown to suppress fatty acid levels and produce mild flushing in short-term clinical studies. This study evaluated the effects of GSK256073 on lipids in subjects with low high-density lipoprotein cholesterol (HDLc). Subjects (n = 80) were randomized (1:1:1:1) to receive GSK256073 5, 50, or 150 mg/day or matching placebo for 8 weeks. The primary end point was determining the GSK256073 exposure-response relationship for change from baseline in HDLc. No significant exposure response was observed between GSK256073 and HDLc levels. GSK256073 did not significantly alter HDLc levels versus placebo, but rather revealed a trend at the 150-mg dose for a nonsignificant decrease in HDLc (-6.31%; P = .12) and an increase in triglycerides (median, 24.4%; 95% confidence interval, 7.3%-41.6%). Flushing was reported in 21%, 25%, and 60% of subjects (5, 50, and 150 mg, respectively) versus 24% for placebo. Results indicated that selective activation of the GPR109A receptor with GSK256073 did not produce niacin-like lipid effects. These findings add to the increasing evidence that niacin-mediated lipoprotein changes occur predominantly via GPR109A-independent pathways.

Pazopanib may reduce bleeding in hereditary hemorrhagic telangiectasia

Pazopanib (Votrient) is an orally administered tyrosine kinase inhibitor that blocks VEGF receptors potentially serving as anti-angiogenic treatment for hereditary hemorrhagic telangiectasia (HHT). We report a prospective, multi-center, open-label, dose-escalating study [50 mg, 100 mg, 200 mg, and 400 mg], designed as a proof-of-concept study to demonstrate efficacy of pazopanib on HHT-related bleeding, and to measure safety. Patients, recruited at 5 HHT Centers, required ≥ 2 Curacao criteria AND [anemia OR severe epistaxis with iron deficiency]. Co-primary outcomes, hemoglobin (Hgb) and epistaxis severity, were measured during and after treatment, and compared to baseline. Safety monitoring occurred every 1.5 weeks. Seven patients were treated with 50 mg pazopanib daily. Six/seven showed at least 50% decrease in epistaxis duration relative to baseline at some point during study; 3 showed at least 50% decrease in duration during Weeks 11 and 12. Six patients showed a decrease in ESS of > 0.71 (MID) relative to baseline at some point during study; 3/6 showed a sustained improvement. Four patients showed > 2 gm improvement in Hgb relative to baseline at one or more points during study. Health-related QOL scores improved on all SF-36 domains at Week 6 and/or Week 12, except general health (unchanged). There were 19 adverse events (AE) including one severe AE (elevated LFTs, withdrawn from dosing at 43 days); with no serious AE. In conclusion, we observed an improvement in Hgb and/or epistaxis in all treated patients. This occurred at a dose much lower than typically used for oncologic indications, with no serious AE. Further studies of pazopanib efficacy are warranted.

Losmapimod, a novel p38 mitogen-activated protein kinase inhibitor, in non-ST-segment elevation myocardial infarction: a randomised phase 2 trial

BACKGROUND

p38 MAPK inhibition has potential myocardial protective effects. We assessed losmapimod, a potent oral p38 MAPK inhibitor, in patients with non-ST-segment elevation myocardial infarction (NSTEMI) in a double-blind, randomised, placebo-controlled trial.

METHODS

From October, 2009, to November, 2011, NSTEMI patients were assigned oral losmapimod (7·5 mg or 15·0 mg loading dose followed by 7·5 mg twice daily) or matching placebo in a 3:3:2 ratio. Safety outcomes were serious adverse events and alanine aminotransferase (ALT) concentrations over 12 weeks, and cardiac events (death, myocardial infarction, recurrent ischaemia, stroke, and heart failure) at 90 days. Efficacy outcomes were high-sensitivity C-reactive protein (hsCRP) and B-type natriuretic peptide (BNP) concentrations at 72 h and 12 weeks, and troponin I area under the curve (AUC) over 72 h. The losmapimod groups were pooled for analysis. This trial is registered with ClinicalTrials.gov, number NCT00910962.

FINDINGS

Of 535 patients enrolled, 526 (98%) received at least one dose of study treatment (losmapimod n=388 and placebo n=138). Safety outcomes did not differ between groups. HsCRP concentrations at 72 h were lower in the losmapimod group than in the placebo group (geometric mean 64·1 nmol/L, 95% CI 53·0-77·6 vs 110·8 nmol/L, 83·1-147·7; p=0·0009) but were similar at 12 weeks. Early geometric mean BNP concentrations were similar at 72 h but significantly lower in the losmapimod group at 12 weeks (37·2 ng/L, 95% CI 32·3-42·9 vs 49·4 ng/L, 38·7-63·0; p=0·04). Mean troponin I AUC values did not differ.

INTERPRETATION

p38 MAPK inhibition with oral losmapimod was well tolerated in NSTEMI patients and might improve outcomes after acute coronary syndromes.

FUNDING

GlaxoSmithKline.

Safety, tolerability, pharmacokinetics and pharmacodynamics of losmapimod following a single intravenous or oral dose in healthy volunteers

AIMS

The purpose of this study was to establish safety and tolerability of a single intravenous (IV) infusion of a p38 mitogen-activated protein kinase inhibitor, losmapimod, to obtain therapeutic levels rapidly for a potential acute coronary syndrome indication. Pharmacokinetics (PK) following IV dosing were characterized, and pharmacokinetic/pharmacodynamic (PK/PD) relationships between losmapimod and phosphorylated heat shock protein 27 (pHSP27) and high-sensitivity C-reactive protein were explored.

METHODS

Healthy volunteers received 1 mg losmapimod IV over 15 min (n = 4) or 3 mg IV over 15 min followed by a washout period and then 15 mg orally (PO; n = 12). Pharmacokinetic parameters were calculated by noncompartmental methods. The PK/PD relationships were explored using modelling and simulation.

RESULTS

There were no deaths, nonfatal serious adverse events or adverse events leading to withdrawal. Headache was the only adverse event reported more than once (n = 3 following oral dosing). Following 3 mg IV and 15 mg PO, Cmax was 59.4 and 45.9 μg l(-1) and AUC0-∞ was 171.1 and 528.0 μg h l(-1) , respectively. Absolute oral bioavailability was 0.62 [90% confidence interval (CI) 0.56, 0.68]. Following 3 mg IV and 15 mg PO, maximal reductions in pHSP27 were 44% (95% CI 38%, 50%) and 55% (95% CI 50%, 59%) occurring at 30 min and 4 h, respectively. There was a 17% decrease (95% CI 9%, 24%) in high-sensitivity C-reactive protein 24 h following oral dosing. A direct-link maximal inhibitory effect model related plasma concentrations to pHSP27 concentrations.

CONCLUSIONS

A single IV infusion of losmapimod in healthy volunteers was safe and well tolerated, and may potentially serve as an initial loading dose in acute coronary syndrome as rapid exposure is achieved.

The study of LoSmapimod treatment on inflammation and InfarCtSizE (SOLSTICE): design and rationale

The p38 mitogen-activated protein kinase (MAPK) is a nexus point in inflammation, sensing, and stimulating cytokine production and driving cell migration and death. In acute coronary syndromes, p38MAPK inhibition could stabilize ruptured atherosclerotic plaques, pacify active plaques, and improve microvascular function, thereby reducing infarct size and risk of subsequent cardiac events. The SOLSTICE trial is randomized, double-blind, placebo-controlled, parallel group, multicenter phase 2a study of 535 patients that evaluates the safety and efficacy of losmapimod (GW856553), a potent oral p38MAPK inhibitor, vs placebo in patients with non-ST-segment elevation myocardial infarction expected to undergo an invasive strategy. The coprimary end points are reduction in high-sensitivity C-reactive protein at 12 weeks and reduction in infarct size as assessed by troponin area under the curve at 72 hours. A key secondary end point is 72-hour and 12-week B-type natriuretic peptide levels as a measure of cardiac remodeling and ventricular strain. The primary safety assessments are serious and nonserious adverse events, results of liver function testing, and major adverse cardiac events. Cardiac magnetic resonance imaging (N = 117) and coronary flow reserve (N = 13) substudies will assess the effects of losmapimod on infarct size, myocardial function, and coronary vasoregulation. Information gained from the SOLSTICE trial will inform further testing of this agent in larger clinical trials.

Effects of p38 mitogen-activated protein kinase inhibition on vascular and systemic inflammation in patients with atherosclerosis

OBJECTIVES

This study sought to determine the effects of a p38 mitogen-activated protein kinase inhibitor, losmapimod, on vascular inflammation, by (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography imaging.

BACKGROUND

The p38 mitogen-activated protein kinase cascade plays an important role in the initiation and progression of inflammatory diseases, including atherosclerosis.

METHODS

Patients with atherosclerosis on stable statin therapy (n = 99) were randomized to receive losmapimod 7.5 mg once daily (lower dose [LD]), twice daily (higher dose [HD]) or placebo for 84 days. Vascular inflammation was assessed by FDG positron emission tomography/computed tomography imaging of the carotid arteries and aorta; analyses focused on the index vessel (the artery with the highest average maximum tissue-to-background ratio [TBR] at baseline). Serum inflammatory biomarkers and FDG uptake in visceral and subcutaneous fat were also measured.

RESULTS

The primary endpoint, change from baseline in average TBR across all segments in the index vessel, was not significantly different between HD and placebo (ΔTBR: -0.04 [95% confidence interval [CI]: -0.14 to +0.06], p = 0.452) or LD and placebo (ΔTBR: -0.02 [95% CI: -0.11 to +0.06], p = 0.579). However, there was a statistically significant reduction in average TBR in active segments (TBR ≥1.6) (HD vs. placebo: ΔTBR: -0.10 [95% CI: -0.19 to -0.02], p = 0.0125; LD vs. placebo: ΔTBR: -0.10 [95% CI: -0.18 to -0.02], p = 0.0194). The probability of a segment being active was also significantly reduced for HD when compared with placebo (OR: 0.57 [95% CI: 0.41 to 0.81], p = 0.002). Within the HD group, reductions were observed in placebo-corrected inflammatory biomarkers including high-sensitivity C-reactive protein (% reduction: -28% [95% CI: -46 to -5], p = 0.023) as well as FDG uptake in visceral fat (ΔSUV: -0.05 [95% CI: -0.09 to -0.01], p = 0.018), but not subcutaneous fat.

CONCLUSIONS

Despite nonsignificant changes for the primary endpoint of average vessel TBR, HD losmapimod reduced vascular inflammation in the most inflamed regions, concurrent with a reduction in inflammatory biomarkers and FDG uptake in visceral fat. These results suggest a systemic anti-inflammatory effect. (A Study to Evaluate the Effects of 3 Months Dosing With GW856553, as Assessed FDG-PET/CT Imaging; NCT00633022).

Apolipoprotein B-100-containing lipoprotein metabolism in subjects with lipoprotein lipase gene mutations

OBJECTIVE

We investigated the impact of lipoprotein lipase (LPL) gene mutations on apolipoprotein B (apoB)-100 metabolism.

METHODS AND RESULTS

We studied 3 subjects with familial LPL deficiency; 14 subjects heterozygous for the LPL gene mutations Gly188Glu, Trp64Stop, and Ile194Thr; and 10 control subjects. Very-low-density lipoprotein (VLDL), intermediate-density lipoprotein (IDL), and low-density lipoprotein (LDL)-apoB-100 kinetics were determined in the fed state using stable isotope methods and compartmental modeling. Compared with controls, familial LPL deficiency had markedly elevated plasma triglycerides and lower VLDL-apoB-100 fractional catabolic rate (FCR), IDL-apoB-100 FCR, VLDL-to-IDL conversion, and VLDL-apoB-100 production rate (P<0.01). Compared with controls, Gly188Glu had higher plasma triglyceride and VLDL- and IDL-apoB-100 concentrations and lower VLDL- and IDL-apoB-100 FCR (P<0.05). Plasma triglycerides were not different, but IDL-apoB-100 concentration and production rate and VLDL-to-IDL conversion were lower in Trp64Stop compared with controls (P<0.05). No differences between controls and Ile194Thr were observed.

CONCLUSIONS

Our results confirm that hypertriglyceridemia is a key feature of familial LPL deficiency. This is due to impaired VLDL- and IDL-apoB-100 catabolism and VLDL-to-IDL conversion. Single-allele mutations of the LPL gene result in modest to elevated plasma triglycerides. The changes in plasma triglycerides and apoB-100 kinetics are attributable to the effects of the LPL genotype.

Mechanism of action of a peroxisome proliferator-activated receptor (PPAR)-delta agonist on lipoprotein metabolism in dyslipidemic subjects with central obesity

CONTEXT

Dyslipidemia increases the risk of cardiovascular disease in obesity. Peroxisome proliferator-activated receptor (PPAR)-δ agonists decrease plasma triglycerides and increase high-density lipoprotein (HDL)-cholesterol in humans.

OBJECTIVE

The aim of the study was to examine the effect of GW501516, a PPAR-δ agonist, on lipoprotein metabolism. Design, Setting, and Intervention: We conducted a randomized, double-blind, crossover trial of 6-wk intervention periods with placebo or GW501516 (2.5 mg/d), with 2-wk placebo washout between treatment periods.

PARTICIPANTS

We recruited 13 dyslipidemic men with central obesity from the general community.

MAIN OUTCOME MEASURES

We measured the kinetics of very low-density lipoprotein (VLDL)-, intermediate-density lipoprotein-, and low-density lipoprotein (LDL)-apolipoprotein (apo) B-100, plasma apoC-III, and high-density lipoprotein (HDL) particles (LpA-I and LpA-I:A-II).

RESULTS

GW501516 decreased plasma triglycerides, fatty acid, apoB-100, and apoB-48 concentrations. GW501516 decreased the concentrations of VLDL-apoB by increasing its fractional catabolism and of apoC-III by decreasing its production rate (P < 0.05). GW501516 reduced VLDL-to-LDL conversion and LDL-apoB production. GW501516 increased HDL-cholesterol, apoA-II, and LpA-I:A-II concentrations by increasing apoA-II and LpA-I:A-II production (P < 0.05). GW501516 decreased cholesteryl ester transfer protein activity, and this was paralleled by falls in the triglyceride content of VLDL, LDL, and HDL and the cholesterol content of VLDL and LDL.

CONCLUSIONS

GW501516 increased the hepatic removal of VLDL particles, which might have resulted from decreased apoC-III concentration. GW501516 increased apoA-II production, resulting in an increased concentration of LpA-I:A-II particles. This study elucidates the mechanism of action of this PPAR-δ agonist on lipoprotein metabolism and supports its potential use in treating dyslipidemia in obesity.

Inhibition of p38 mitogen-activated protein kinase improves nitric oxide-mediated vasodilatation and reduces inflammation in hypercholesterolemia

BACKGROUND

Oxidized low-density lipoprotein reduces endothelial nitric oxide production (an important mediator of vasoregulation) and activates p38 mitogen-activated protein kinase (MAPK), a mediator of vascular inflammation. Animal models of vascular stress have previously predicted improvements in vascular function after p38 MAPK inhibition. We hypothesized that a selective p38α/β MAPK inhibitor (losmapimod; GW856553) would improve compromised nitric oxide-mediated vasoregulation in patients with hypercholesterolemia.

METHODS AND RESULTS

Untreated hypercholesterolemic patients (low-density lipoprotein cholesterol >4.1 mmol/L) were randomized to receive losmapimod 7.5 mg (n=27) or placebo (n=29) twice daily for 28 days. Patients with known vascular disorders (eg, diabetes mellitus, coronary heart disease) were excluded. Forearm blood flow was measured by venous occlusion plethysmography in response to serial intra-arterial infusion of acetylcholine, sodium nitroprusside, and N(G)-monomethyl-L-arginine (L-NMMA). Acetylcholine and L-NMMA responses were significantly impaired (P=0.01 and P=0.03) compared with responses in control subjects (n=12). In hypercholesterolemic patients treated with losmapimod, responses to acetylcholine were improved by 25% (95% confidence interval, 5 to 48; P=0.01), to sodium nitroprusside by 20% (95% confidence interval, 3 to 40; P=0.02), and to L-NMMA by 10% (95% confidence interval, -1 to 23; P=0.07) compared with placebo. C-reactive protein was reduced by 57% (95% confidence interval, -81 to -6%; P<0.05) in patients treated with losmapimod compared with placebo.

CONCLUSIONS

Losmapimod improves nitric oxide-mediated vasodilatation in hypercholesterolemic patients, which is consistent with findings in previous translational animal models. These data support the hypothesis that attenuating the inflammatory milieu by inhibiting p38 MAPK activity improves NO activity. This suggests p38 MAPK as a novel target for patients with cardiovascular disease.

Inhibition of p38 mitogen-activated protein kinase reduces inflammation after coronary vascular injury in humans

OBJECTIVE

To evaluate whether a p38α/β mitogen-activated protein kinase inhibitor, SB-681323, would limit the elevation of an inflammatory marker, high-sensitivity C-reactive protein (hsCRP), after a percutaneous coronary intervention (PCI).

METHODS AND RESULTS

Coronary artery stents provide benefit by maintaining lumen patency but may incur vascular trauma and inflammation, leading to myocardial damage. A key mediator for such stress signaling is p38 mitogen-activated protein kinase. Patients with angiographically documented coronary artery disease receiving stable statin therapy and about to undergo PCI were randomly selected to receive SB-681323, 7.5 mg (n=46), or placebo (n=46) daily for 28 days, starting 3 days before PCI. On day 3, before PCI, hsCRP was decreased in the SB-681323 group relative to the placebo group (29% lower; P=0.02). After PCI, there was a statistically significant attenuation in the increase in hsCRP in the SB-681323 group relative to the placebo group (37% lower on day 5 [P=0.04]; and 40% lower on day 28 [P=0.003]). There were no adverse safety signals after 28 days of treatment with SB-681323.

CONCLUSIONS

In the setting of statin therapy, SB-681323 significantly attenuated the post-PCI inflammatory response, as measured by hsCRP. This inflammatory dampening implicates p38 mitogen-activated protein kinase in the poststent response, potentially defining an avenue to limit poststent restenosis.

Mechanism of inhibition defines CETP activity: a mathematical model for CETP in vitro

Because cholesteryl ester transfer protein (CETP) inhibition is a potential HDL-raising therapy, interest has been raised in the mechanisms and consequences of CETP activity. To explore these mechanisms and the dynamics of CETP in vitro, a mechanistic mathematical model was developed based upon the shuttle mechanism for lipid transfer. Model parameters were estimated from eight published experimental datasets, and the resulting model captures observed dynamics of CETP in vitro. Simulations suggest the shuttle mechanism yields behaviors consistent with experimental observations. Three key findings predicted from model simulations are: 1) net CE transfer activity from HDL to VLDL and LDL can be significantly altered by changing the balance of homoexchange versus heteroexchange of neutral lipids via CETP; 2) lipemia-induced increases in CETP activity are more likely caused by increases in lipoprotein particle size than particle number; and 3) the inhibition mechanisms of the CETP inhibitors torcetrapib and JTT-705 are significantly more potent than a classic competitive inhibition mechanism with the irreversible binding mechanism having the most robust response. In summary, the model provides a plausible representation of CETP activity in vitro, corroborates strong evidence for the shuttle hypothesis, and provides new insights into the consequences of CETP activity and inhibition on lipoproteins.

Emerging cardiovascular risk factors that account for a significant portion of attributable mortality risk in chronic kidney disease

Chronic kidney disease (CKD) increases cardiovascular risk and mortality. However, traditional cardiovascular risk factors do not adequately account for the substantial increase in mortality observed in CKD. The aim of this study was to examine the relative contributions of novel cardiovascular risk factors to the risk between CKD and mortality. The study population included 4,680 consecutive new patients from a tertiary care preventive cardiology program from 1996 to 2005. Estimated glomerular filtration rate was calculated using the Modification of Diet in Renal Disease (MDRD) method. Baseline levels of traditional (low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, hypertension, triglycerides, total cholesterol, and fasting glucose) and emerging (apolipoproteins A-I and B, lipoprotein[a], fibrinogen, homocysteine, and high-sensitivity C-reactive protein) risk factors were examined. All-cause mortality was obtained from the Social Security Death Index. There were 278 deaths over a median follow-up period of 22 months. CKD (estimated glomerular filtration rate <or=60 ml/min/1.73 m(2)) was strongly associated with mortality after adjusting for traditional cardiovascular risk factors (hazard ratio 2.31, 95% confidence interval 1.77 to 3.11, p<0.001) and with the addition of propensity score (hazard ratio 2.33, 95% confidence interval 1.75 to 3.10, p<0.001). Of all the traditional and emerging risk factors monitored, only the addition of homocysteine and fibrinogen significantly attenuated the association between CKD and mortality (adjusted hazard ratio 1.73, 95% confidence interval 1.23 to 2.34, p<0.001), explaining 38% of the attributable mortality risk from CKD. A significant interaction (p=0.004) between homocysteine and estimated glomerular filtration rate was observed whereby the annual mortality rate in subjects with CKD with homocysteine <10 micromol/L (the bottom tertile) was similar to those with normal renal function (1% per year), whereas homocysteine levels >or=12.5 micromol/L (the top tertile) were associated with a sevenfold greater mortality risk. In conclusion, homocysteine and fibrinogen levels explain nearly 40% of the attributable mortality risk from CKD.

Triglyceride:high-density lipoprotein cholesterol effects in healthy subjects administered a peroxisome proliferator activated receptor delta agonist

OBJECTIVE

Exercise increases fatty acid oxidation (FAO), improves serum high density lipoprotein cholesterol (HDLc) and triglycerides (TG), and upregulates skeletal muscle peroxisome proliferator activated receptor (PPAR)delta expression. In parallel, PPARdelta agonist-upregulated FAO would induce fatty-acid uptake (via peripheral lipolysis), and influence HDLc and TG-rich lipoprotein particle metabolism, as suggested in preclinical models.

METHODS AND RESULTS

Healthy volunteers were allocated placebo (n=6) or PPARdelta agonist (GW501516) at 2.5 mg (n=9) or 10 mg (n=9), orally, once-daily for 2 weeks while hospitalized and sedentary. Standard lipid/lipoproteins were measured and in vivo fat feeding studies were conducted. Human skeletal muscle cells were treated with GW501516 in vitro and evaluated for lipid-related gene expression and FAO. Serum TG trended downwards (P=0.08, 10 mg), whereas TG clearance post fat-feeding improved with drug (P=0.02). HDLc was enhanced in both treatment groups (2.5 mg P=0.004, 10 mg P<0.001) when compared with the decrease in the placebo group (-11.5+/-1.6%, P=0.002). These findings complimented in vitro cell culture results whereby GW501516 induced FAO and upregulated CPT1 and CD36 expression, in addition to a 2-fold increase in ABCA1 (P=0.002). However, LpL expression remained unchanged.

CONCLUSIONS

This is the first report of a PPARdelta agonist administered to man. In this small study, GW501516 significantly influenced HDLc and TGs in healthy volunteers. Enhanced in vivo serum fat clearance, and the first demonstrated in vitro upregulation in human skeletal muscle fat utilization and ABCA1 expression, suggests peripheral fat utilization and lipidation as potential mechanisms toward these HDL:TG effects.

Skin cholesterol adds to Framingham risk assessment

INTRODUCTION

It has been demonstrated that skin tissue cholesterol (SkinTc) is associated with angiographic disease. Now, we further delineate the relative risk of multivessel disease (>50% stenosis in at least two vessels) in the conjoint presence of high SkinTc and high traditional risk burden.

METHODS

Patients scheduled for angiography (N = 649) had SkinTc measured immediately prior to the procedure. Patients were classified according to the presence of high (>110) SkinTc and high (>10) Framingham global risk scores. Multivariable logistic regression models were used to estimate relative risk of multivessel disease for patients with isolated high skin tissue cholesterol, isolated high Framingham risk or conjoint high skin tissue cholesterol and high Framingham risk (each compared to neither factor elevated).

RESULTS

The mean age was 63 +/- 12 years and 33% (n = 214) were women. Thirty seven percent (n = 237) had angiographically determined multivessel disease. Patients with isolated high SkinTc showed a relative risk of multivessel disease of 1.6 (95% CI = 1.0-2.4), while patients with isolated high Framingham risk had an odds ratio of 1.8 (CI = 1.0-3.4). However, when both scores were elevated, risk of multivessel disease was increased 4.3 times (CI = 2.6-7.2) compared to neither elevated.

CONCLUSIONS

We see an independent, additive risk of concurrent multivessel disease when Framingham risk and skin cholesterol are both elevated. Skin tissue cholesterol may have value in further stratifying subjects with Framingham scores >10.

Sensitivity and specificity of pediatric lipid determinations for adult lipid status: findings from the Princeton Lipid Research Clinics Prevalence Program Follow-up Study

OBJECTIVE

The goal was to determine the diagnostic utility of the National Cholesterol Education Program pediatric guidelines.

METHODS

With the use of pediatric lipid data from the Cincinnati Clinic of the Lipid Research Clinics Prevalence Study and lipid and cardiovascular disease data collected for the same subjects as adults in the Princeton Follow-up Study, the sensitivity and specificity of the National Cholesterol Education Program pediatric guidelines were calculated overall and according to age. Furthermore, whether use of parental cardiovascular disease history during childhood influenced the sensitivity and specificity was assessed.

RESULTS

Overall sensitivities were 43% to 46% and specificities were 82% to 86% for total and low-density lipoprotein cholesterol levels. There was considerable variation in sensitivities according to age, with the lowest sensitivities at ages 14 to 16 years and the highest sensitivities at ages 5 to 10 years and 17 to 19 years. Results were similar whether or not the population was restricted to children with a positive parental history of cardiovascular disease.

CONCLUSIONS

Results of our analyses suggest that the sensitivity and specificity for evaluating total cholesterol or low-density lipoprotein cholesterol levels that are elevated in adulthood are not improved by selecting children with a positive parental history. These data also show the strong role that age (particularly the pubertal years between 10 and 15 years of age) plays in lipid measurements for children and adolescents. Continued prospective and longitudinal studies designed with age as well as other risk parameters are needed to determine the best guidelines for clinical screening in the future.

The independent correlation between high-density lipoprotein cholesterol and subsequent major adverse coronary events

BACKGROUND

There is substantial evidence from clinical trials that lowering low-density lipoprotein cholesterol (LDL-C) reduces cardiovascular risk. There is less evidence for the salutatory effects of raising high-density lipoprotein cholesterol (HDL-C). The predictive strength of an initial HDL-C measurement and its change over time for major adverse coronary events is not well understood.

METHODS

We identified a cohort of all 6928 patients in an urban primary care practice who had two or more lipid measurements between January 1985 and December 1997. We used bivariable and multivariable (Cox proportional hazards) techniques to identify independent predictors of subsequent major adverse coronary events (hospitalization for myocardial infarction or acute coronary syndrome) after the second set of lipid measurements.

RESULTS

The time between first and second lipid measurements averaged 2.6 years. During a mean of 5.1 +/- 3.2 years of observation after their second lipid measurements, 2167 (31%) patients had an acute coronary event. Patients having events were significantly older, more often white, male, and smokers and more often had antecedent diabetes, hypertension, coronary heart disease, and myocardial infarctions. Adjusting for covariates, a 10-mg/dL higher initial HDL-C was associated with an 11% (95% CI 7%-14%) lower risk of coronary events. A 10-mg/dL increase in HDL-C between lipid measurements was associated with a 7% (95% CI 3%-10%) lower risk of events. Neither initial or change in triglycerides nor LDL-C predicted subsequent coronary events.

CONCLUSION

High-density lipoprotein cholesterol measurements and change in HDL-C predicted major adverse coronary events in this urban practice, which provides support studying interventions targeting HDL-C for cardiovascular risk reduction.

The association between fibrate use, change in high-density lipoprotein cholesterol, and the risk of cardiovascular disease: A retrospective chart review involving up to 8 years of follow-up

BACKGROUND

Clinical trials have indicated that the use of fibric acid derivatives confers a benefit against cardiovascular disease (CVD) in selected populations. However, whether fibrates provide a CVD risk reduction independent of changes in the traditional lipoprotein fractions and other known CVD risk factors is not clear.

OBJECTIVE

This study examined whether the use of fibrate therapy in a general clinical setting provided cardiovascular benefits independent of changes in the traditional lipoprotein fractions.

METHODS

This was a matched, retrospective cohort study. From the electronic records of a large health maintenance organization in the northwestern United States, we identified a population that had newly initiated fibrate pharmacotherapy between January 1, 1996, and December 31, 2000. We then identified a comparator group of patients not using fibrates, matching them to fibrate users based on high-density lipoprotein cholesterol (HDL-C) and triglyceride (TG) levels, age, sex, and year of HDL-C and TG measurement. Subjects were followed until a CVD hospitalization, termination from the health plan, or December 31, 2003, whichever came first. We then used multivariate analysis accounting for differences in followup to identify predictors of CVD incidence.

RESULTS

The study population included 1722 matched pairs (56.6% male; mean [SD] age, 57.3 [11.1] years). The patients who had newly initiated fibrate pharmacotherapy had low baseline HDL-C levels (mean, 37.4 mg/dL) and very high TG levels (617 mg/dL). The 2 groups were similar overall, with the only significant differences between fibrate users and nonfibrate controls being a greater prevalence of diabetes (37.7% vs 34.3%, respectively; P=0.040) and greater use of angiotensin-converting enzyme inhibitors/angiotensin-receptor blockers (56.6% vs 51.6%, respectively; P=0.003), beta-blockers (53.7% vs 49.0%; P=0.006), calcium channel blockers (25.1% vs 20.9%; P=0.004), and niacin (11.7% vs 7.4%; P<0.001). Overall, CVD risk was 26% lower for every 5-mg/dL increment in HDL-C. After adjustment for age, sex, smoking history, diabetes, existing diagnosis of CVD, weight, systolic blood pressure, baseline HDL-C, change in HDL-C, total cholesterol, TG, and use of statins, niacin, and other CVD drugs, fibrate use did not confer an additional CVD risk reduction.

CONCLUSIONS

In this cohort with low baseline HDL-C levels and very high TG levels, fibrate use did not confer an independent CVD risk reduction after adjustment for CVD risk factors. Given the current obesity epidemic in the United States and the corresponding rise in the number of patients with the metabolic syndrome, the apparent risk reduction observed in association with higher HDL-C levels should not be ignored.

Elevated skin tissue cholesterol levels and myocardial infarction

BACKGROUND

Skin cholesterol has been associated with coronary artery disease, extent of angiographic disease and inflammatory markers such as hs-CRP. Based on these findings we sought to determine whether skin cholesterol was associated with myocardial infarction (MI).

METHODS

Patients (N = 649) underwent diagnostic catheterization and concurrent skin cholesterol measurement. History of MI was determined at the time of hospitalization.

RESULTS

Patients with a history of MI (n = 225, 35%) had significantly higher skin cholesterol than those without MI (127+/-29 versus 120+/-20, p = 0.002). The odds ratio for high skin cholesterol (for MI) was 1.6 (95% CI = 1.1, 2.6; p = 0.01) after adjustment for traditional risk and extent of angiographic disease.

CONCLUSION

Skin cholesterol may indicate increased risk of coronary-related events rather than simply the presence of angiographic narrowing.

Impact of nonprescriptive factors on low-density lipoprotein cholesterol reduction with statins

Nonprescriptive factors, including patient adherence, can affect the fluctuations in low-density lipoprotein (LDL) cholesterol observed in the clinical setting. In 241 statin-treated patients, although drugs and doses remained fixed, 57% of patients initially successful in reaching LDL cholesterol targets showed subsequent increases in LDL cholesterol. Conversely, 60% of patients who initially failed to reach targets had subsequent reductions in LDL cholesterol, with nearly 1/3 eventually attaining their LDL cholesterol goals.

Skin tissue cholesterol (SkinTc) is related to angiographically-defined cardiovascular disease

Parallel changes associated with aging found in the vasculature and skin at necropsy, have prompted small preliminary studies to assess the relation between skin tissue cholesterol (SkinTc) and cardiovascular disease. While these studies have been suggestive, no formal investigation is available to test this association. It would, therefore, be valuable to determine whether a relation between SkinTc and angiographic narrowing actually exists, the latter representing one accepted measurement of coronary atherosclerosis.

METHODS

Patients at three hospitals undergoing coronary angiography and not on lipid altering agents (n = 649) were examined for skinTc using a non-invasive method. Vessels were evaluated manually (number with stenosis > or = 50%). Clinical characteristics, current medication use, and Framingham global risk score were recorded.

RESULTS

SkinTc was significantly higher in patients with angiographic disease (124 +/- 30 vs. 118 +/- 30, P = 0.02). After adjustment for traditional coronary artery disease risk factors, SkinTc provided 7% additional risk (per 10 SkinTc units) for angiographic disease.

CONCLUSION

SkinTc, measured with a non-invasive method, is associated with the presence of coronary artery disease as determined by catheterization. Such an assay may eventually help stratify patient risk and target prevention efforts.

Relation of homocysteine and C-reactive protein to urinary albumin loss

This study shows that elevated high-sensitivity C-reactive protein and plasma total homocysteine contribute independently to the likelihood of an increased urinary albumin:creatinine ratio. This result suggests that total homocysteine and C-reactive protein may be acting by separate mechanistic pathways.

Association Between Apolipoprotein E Alleles and Calcific Valvular Heart Disease

Background— Studies on apolipoprotein E (apoE) alleles have reported an increased risk of coronary heart disease in patients with the apoE4 allele. Given the risk factor and histological similarities between coronary and calcific valvular heart disease (aortic stenosis [AS] and mitral annular calcification [MAC]), we postulated that apoE alleles might be associated with the development of these valvular lesions.

Methods and Results— We evaluated the association between apoE alleles and calcific valvular lesions in 802 patients undergoing transthoracic echocardiography using logistic regression analyses. No difference was noted in genotype distribution ( P =0.59) or prevalence of apoE4 between those with or without MAC (30% versus 27%, respectively; P =0.57). Compared with patients without AS, the genotype distribution of patients with AS differed significantly ( P =0.03), with increasing prevalences of the apoE 4 allele (27% in those without versus 40% in those with AS; P =0.01). In multivariate analyses adjusting for age, gender, low-density lipoprotein cholesterol levels, and coronary artery disease, increasing age and the apoE4 allele were significant independent predictors of AS (odds ratio, 1.94; 95% confidence interval, 1.01 to 3.71; P =0.046), whereas the apoE4 allele was not predictive of MAC.

Conclusions— These findings support extension of the importance of the apoE4 allele beyond atherosclerosis and Alzheimer’s disease to calcific AS.

Relation of albumin/creatinine ratio to C-reactive protein and to the metabolic syndrome

We hypothesized that the association of high sensitivity C-reactive protein (CRP) with urinary albumin excretion (UAE) is predominately mediated through its correlation with the metabolic syndrome. Serum CRP and urine albumin:creatinine ratios (ACR) from 720 preventive cardiology patients were analyzed to estimate age- and gender-adjusted relative risk of high CRP and metabolic syndrome for high ACR. These data demonstrate that CRP independently predicts the presence of UAE, a marker of endothelial dysfunction.

Statins promote potent systemic antioxidant effects through specific inflammatory pathways

BACKGROUND

The pleiotropic actions of hydroxymethylglutaryl CoA reductase inhibitors (statins) include antiinflammatory and antioxidant actions. We recently reported that statins induce reductions in plasma protein levels of nitrotyrosine (NO2Tyr), a modification generated by nitric oxide-derived oxidants. Whether alternative oxidative pathways are suppressed in vivo after statin administration has not yet been reported.

METHODS AND RESULTS

As an extension of our prior study, hypercholesterolemic subjects with no known coronary artery disease were evaluated at baseline and after 12 weeks of atorvastatin therapy (10 mg/d). Plasma levels of protein-bound chlorotyrosine, NO2Tyr, dityrosine, and orthotyrosine, specific molecular fingerprints for distinct oxidative pathways upregulated in atheroma, were determined by mass spectrometry. In parallel, alterations in lipoproteins and C-reactive protein were determined. Statin therapy caused significant reductions in chlorotyrosine, NO2Tyr, and dityrosine (30%, 25%, and 32%, respectively; P<0.02 each) that were similar in magnitude to reductions in total cholesterol and apolipoprotein B-100 (25% and 29%, P<0.001 each). Nonsignificant decreases in orthotyrosine and C-reactive protein levels were observed (9% and 11%, respectively; P>0.10 each). Statin-induced reductions in oxidation markers were independent of decreases in lipids and lipoproteins.

CONCLUSIONS

Statins promote potent systemic antioxidant effects through suppression of distinct oxidation pathways. The major pathways inhibited include formation of myeloperoxidase-derived and nitric oxide-derived oxidants, species implicated in atherogenesis. The present results suggest potential mechanisms that may contribute to the beneficial actions of statins. They also have important implications for monitoring the antiinflammatory and antioxidant actions of these agents.

Sex hormones and the changes in adolescent male lipids: longitudinal studies in a biracial cohort

OBJECTIVE

To determine the role of increasing free testosterone and estradiol in pubertal changes in male lipids.

METHODS

We conducted a 3-year, longitudinal, observation study with biannual visits of 251 black and 285 white boys who were 10 to 15 years of age at enrollment. Sex hormones, lipid parameters, and body composition measures were obtained according to a standard protocol. The body mass index (kg/m(2)) was used to characterize obesity.

RESULTS

White boys had higher triglycerides, lower high-density lipoprotein cholesterol (HDL-C), lower apolipoprotein (apo)AI, and higher apoB than black boys. In boys of both races, increased body mass index was associated with increases in triglycerides, low-density lipoprotein cholesterol, apoB and decreases in HDL-C and apoAII. Within this framework, increased free testosterone was associated with increased apoB and decreased HDL-C and apoAI, whereas increased estradiol was associated with increased HDL-C and decreased triglycerides, low-density lipoprotein cholesterol, and apoB.

CONCLUSION

Changes in sex steroid hormones have significant effects on changes in lipid parameters-increasing free testosterone levels has atherogenic effects and increasing estradiol has antiatherogenic effects.

The Lescol Intervention Prevention Study (LIPS): start all patients on statins early after PCI

The Lescol Intervention Prevention Study (LIPS) was the first randomized trial to show a significant reduction in the risk of cardiac events in patients started on fluvastatin immediately after a successful percutaneous coronary intervention. The benefit was independent of baseline cholesterol levels. The results suggest that all patients should be discharged on lipid-lowering therapy after a percutaneous coronary intervention. Currently, this is seldom done.

Association of nitrotyrosine levels with cardiovascular disease and modulation by statin therapy

CONTEXT

Formation of nitric oxide-derived oxidants may serve as a mechanism linking inflammation to development of atherosclerosis. Nitrotyrosine, a specific marker for protein modification by nitric oxide-derived oxidants, is enriched in human atherosclerotic lesions and low-density lipoprotein (LDL) recovered from human atheroma.

OBJECTIVES

To determine whether systemic levels of nitrotyrosine are associated with the prevalence of coronary artery disease (CAD) and are modulated by hydroxymethylglutaryl coenzyme-A reductase inhibitor (statin) therapy.

DESIGN, SETTING, AND PATIENTS

A case-control and interventional study at 2 urban tertiary-care referral centers; recruitment for each was from June 1, 2001, until January 1, 2002. For the case-control study, 100 case-patients with established CAD and 108 patients with no clinically evident CAD were recruited consecutively. In the interventional study, participants aged 21 years or older with hypercholesterolemia (LDL cholesterol > or =130 mg/dL [> or =3.5 mmol/L]) underwent nutrition and exercise counseling. Those whose levels did not decrease with 6 to 8 weeks were enrolled in the study (n = 35). For 12 weeks, they received 10 mg/d of oral atorvastatin therapy.

MAIN OUTCOME MEASURES

In the case-control study, the association between systemic levels of protein-bound nitrotyrosine, CAD risk, and presence of CAD. In the interventional study, the change in nitrotyrosine, lipoprotein, and C-reactive protein (CRP) levels.

RESULTS

Nitrotyrosine levels were significantly higher among patients with CAD (median 9.1 micromol/mol [interquartile range, 4.8-13.8 micromol/mol] tyrosine vs 5.2 micromol/mol [interquartile range, 2.2-8.4 micromol/mol]; P<.001). Patients in the upper quartile of nitrotyrosine (29%; P<.001) had a higher odds of CAD compared with those in the lowest quartile (unadjusted odds ratio, 6.1; 95% confidence interval, 2.6-14.0; P<.001). In multivariate models adjusting for Framingham Global Risk Score and CRP, upper quartiles of nitrotyrosine remained associated with CAD (odds ratio, 4.4; 95% confidence interval, 1.8-10.6; P<.001). Statin therapy reduced nitrotyrosine levels significantly (25%; P<.02) with a magnitude similar to reductions in total cholesterol levels (25%; P<.001) and LDL particle number (29%; P<.001) yet were independent of alterations in lipoproteins and inflammatory markers like CRP.

CONCLUSIONS

The findings from this preliminary study indicate that nitrotyrosine levels are associated with the presence of CAD and appear to be modulated by statin therapy. These results suggest a potential role for nitric oxide-derived oxidants as inflammatory mediators in CAD and may have implications for atherosclerosis risk assessment and monitoring of anti-inflammatory actions of statins.

A truly deadly quartet: obesity, hypertension, hypertriglyceridemia, and hyperinsulinemia

The National Cholesterol Education Program recognizes the importance of the metabolic syndrome and has published guidelines for its diagnosis. Weight loss, physical activity, and treatment of the individual risk factors constitute the main strategies for treatment. For now, the goals and methods of treating hypertension and dyslipidemia are the same in people with the metabolic syndrome as in the general population. Thiazolidinedione drugs increase insulin sensitivity, but their use in the metabolic syndrome is only speculative at present. We recommend they be used only as indicated to treat diabetes mellitus.

Statins do not meet expectations for lowering low-density lipoprotein cholesterol levels when used in clinical practice

BACKGROUND

Statins have become a mainstay in the treatment of hyperlipidemia, based on their potency and favorable side-effect profile. Drug choice is presumed to be guided by the estimated degree of low-density lipoprotein (LDL) cholesterol lowering required in a particular patient and the projected efficacy of any drug-dose combination, as contained in the package inserts for each medication. We investigated whether these expectations were met in a clinical practice.

METHODS

Data were analyzed for 367 hyperlipidemic patients in a preventive cardiology practice who were not taking statins at entry, who were given a standard statin dose at their first visit, and who had at least one follow-up visit on the same drug/dose. Expected LDL cholesterol reductions were calculated for each patient based on guidelines in the package inserts for each drug.

RESULTS

The mean (+/-SD) observed LDL cholesterol reduction of 26% +/- 20% was significantly less than expected (34% +/- 7%, P < 0.001). The ratio of observed to expected reduction was not different for the three statins used (atorvastatin, 0.79 +/- 0.48; simvastatin, 0.88 +/- 0.61; pravastatin, 0.75 +/- 0.69; P = 0.39).

CONCLUSIONS

The use of statins in a clinical practice led to observed reductions in LDL cholesterol level that were significantly less than those projected by package insert guidelines. We believe this gap reflects the reduced patient compliance frequently observed in clinical practice settings, rather than any inherent difference in statin responsiveness of a practice versus a trial population. Physicians should be aware of this disparity when using statins in the clinical setting.

Fiber-multivitamin combination therapy: a beneficial influence on low-density lipoprotein and homocysteine

Proven effective alternative and adjunctive therapies for lipid lowering could be beneficial for patients with hyperlipidemia. We evaluated a 90% soluble fiber for its ability to alter lipid, lipoprotein, and homocysteine levels in the setting of coadministered folate and B vitamins. Patients (n = 119) were randomized to either the fiber and vitamin combination, or placebo. Fasting lipid, glucose, and homocysteine concentrations, and body mass index (BMI) were obtained at baseline and weeks 4 and 8. Both between-group (Wilcoxon rank-sum test) and within-group (paired t test) comparisons were used to evaluate treatment effects. After 6 weeks of a diet therapy (National Cholesterol Education Program [NECP] Step I) run-in period, subjects in both groups had similar low-density lipoprotein cholesterol (LDL-C) levels (159 mg/dL v 158 mg/dL). The treated group showed a 7.1% +/- 11.6% reduction by 4 weeks, which was maintained at 8 weeks (7.9% +/- 11.0%). Placebo patients had a slight increase in LDL-C values over the same period (+2.4% +/- 11.7%), for a 10.3% difference between groups. The treatment effect was statistically significant both between groups (P <.001) and within the active-treatment group (P <.001) after the 8-week intervention. Apolipoprotein B (ApoB) levels in a representative subset of the treated group (n = 53) decreased by 20% (P =.004). The fiber blend neither raised triacylglycerol (TG) (P =.95) nor lowered high-density lipoprotein cholesterol (HDL-C) levels (P =.54), and lowered homocysteine (active, 9.8 to 8.7/micromol/L, P =.02; placebo, 9.4 to 9.2 /micromol/L, P =.98). Thus, a significant LDL-C lowering effect, with parallel Apo B reduction, was demonstrated for this fiber/vitamin combination. No adverse changes on TG or HDL-C levels were noted, and folate/B vitamin benefits attributed to homocysteine reduction were preserved. Concurrent administration of fiber and vitamins represents a preventive approach that may reduce the need for concomitant lipid-lowering therapies or serve as an adjunct therapy.

Pilot study of coronary atherosclerotic risk and plaque burden in HIV patients: 'a call for cardiovascular prevention'

BACKGROUND

Highly active antiretroviral therapy (HAART) has dramatically improved the life expectancy of patients with human immunodeficiency virus (HIV) prompting increasing concerns related to chronic management. Suggestions of greater cardiovascular risk, partially related to recently proposed HAART-induced dyslipidemia and glucose intolerance, amplify these concerns. At this time, further corroboration of the emerging evidence for increased coronary risk, as well as complimentary estimates of coronary artery atherosclerotic burden, would be valuable to practicing physicians.

METHODS

Seventeen HIV patients on HAART (all from the same HIV clinic population) without coronary artery disease (CAD) were referred to Preventive Cardiology for treatment of dyslipidemia ('referred group'). Upon entry, they underwent computed tomography (CT) of the coronary arteries. Subsequently, the referred group was matched (1:4) for age, gender and traditional risk to non-HIV non-CAD subjects (matched group, n=68) from the University of Illinois CT database. A serial review of 90 subjects from the original HIV population was sampled to determine general cardiovascular risk.

RESULTS

Thirteen (76%) of the 17 referred patients revealed the presence of coronary calcium compared with 63% in the matched HIV seronegative controls (P=0.18). Log-transformed median calcium score was 2.93+/-2.3 in the referred group versus 1.97+/-2.5 in the matched group (P=0.09). Fifty one percent of the overall population smoked cigarettes, 11% were diabetic (30% diagnosed pre-HAART and 70% post-HAART) and 30% were hypertensive (33% diagnosed pre-HAART and 67% post-HAART).

CONCLUSIONS

In a particularly dyslipidemic subgroup of HIV subjects without known CAD we found evidence for atherosclerosis in three-quarters based on coronary calcium. Further, in this population of HIV patients on HAART, we found an enhanced prevalence of traditional cardiovascular risk. This pilot study encourages the development of preventive strategies in this population.

Elevated fibrinogen and homocysteine levels enhance the risk of mortality in patients from a high-risk preventive cardiology clinic

Fibrinogen (Fib) plays an important role in platelet aggregation and thrombus formation, and homocysteine (tHcy) causes endothelial dysfunction and injury. Therefore, an interaction toward an enhanced risk of thrombotic events and consequent mortality might be expected in patients with both factors elevated. To determine whether patients exposed jointly to high Fib and high tHcy were at increased risk of mortality, we compared them with those with only one or neither risk factors elevated. Prevalence of coronary artery disease (cross-section) and short-term mortality (30+/-14 months) were assessed in 2084 patients with available baseline tHcy and Fib. Upper quartiles were used to define high tHcy (>14.2 micromol/L) and high Fib (>382 mg/dL). Cox models adjusting for Framingham risk score, creatinine, and coronary artery disease status were used to estimate the risk of high tHcy and high Fib and their combinations. Mean age of the patients was 56+/-12 years (35% women) with 71 (3.4%) recorded deaths. Risk-adjusted longitudinal models showed a hazard ratio of 2.14 (P=0.03) for isolated high tHcy, 2.28 (P=0.02) for isolated high Fib, and 3.29 (P<0.001) for both high tHcy and high Fib in comparison with neither risk factor high. Independence of each parameter and lack of synergism was found on longitudinal as well as cross-sectional analyses. Conjoint elevation of Fib and tHcy increased the risk of death by approximately 3-fold in three years. Although no significant interaction between Fib and tHcy was demonstrated, both provided independent information after adjustment for traditional risk factors.

Serum testosterone associates with lower high-density lipoprotein cholesterol in black and white males, 10 to 15 years of age, through lowered apolipoprotein AI and AII concentrations

High-density lipoprotein cholesterol (HDL-C) concentrations decrease during adolescence in males in association with increasing pubertal maturation and free testosterone (F-T). To determine whether F-T effects lower HDL-C levels by decreasing the amount of cholesterol associated with the major protein moeities associated with HDL-C (apolipoprotein [apo]AI and AII) or by decreasing the concentrations of these proteins, we studied 251 black and 285 white boys, ages 10 to 15 years. In cross-sectional analysis, advancing puberty associated with decreasing HDL-C, apoAI, and apoAII in boys of each ethnic group. The decreases were greater in white (1.49 to 1.24 mmol/L) than black boys (1.68 to 1.53 mmol/L). Backward stepwise regression analyses indicated that F-T was a significant negative predictor of all 3 lipid parameters--HDL-C, apoAI, and apoAII. Ethnic group was associated with HDL-C (blacks higher) and apoAII (whites higher), but not apoAI. The ratio of HDL-C to apo (AI+AII) varied significantly (and negatively) with body mass index (BMI; kg/m(2)), but not with pubertal stage or F-T. Thus, increased F-T appears to explain decreased HDL-C via decreased apoAI and apoAII, not decreases in the amount of cholesterol associated with these proteins.