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Background: Cerebral microbleeds (CMBs) have been observed in healthy elderly people undergoing systematic brain magnetic resonance imaging. The potential role of acute triggers on the appearance of CMBs remains unknown. We aimed to describe the incidence of new CMBs after transcatheter aortic valve replacement (TAVR) and to identify clinical and procedural factors associated with new CMBs including hemostatic measures and anticoagulation management., Methods: We evaluated a prospective cohort of patients with symptomatic aortic stenosis referred for TAVR for CMBs (METHYSTROKE [Identification of Epigenetic Risk Factors for Ischemic Complication During the TAVR Procedure in the Elderly]). Standardized neurologic assessment, brain magnetic resonance imaging, and analysis of hemostatic measures including von Willebrand factor were performed before and after TAVR. Numbers and location of microbleeds on preprocedural magnetic resonance imaging and of new microbleeds on postprocedural magnetic resonance imaging were reported by 2 independent neuroradiologists blinded to clinical data. Measures associated with new microbleeds and postprocedural outcome including neurologic functional outcome at 6 months were also examined., Results: A total of 84 patients (47% men, 80.9±5.7 years of age) were included. On preprocedural magnetic resonance imaging, 22 patients (26% [95% CI, 17%-37%]) had at least 1 microbleed. After TAVR, new microbleeds were observed in 19 (23% [95% CI, 14%-33%]) patients. The occurrence of new microbleeds was independent of the presence of microbleeds at baseline and of diffusion-weighted imaging hypersignals. In univariable analysis, a previous history of bleeding ( P =0.01), a higher total dose of heparin ( P =0.02), a prolonged procedure ( P =0.03), absence of protamine reversion ( P =0.04), higher final activated partial thromboplastin time ( P =0.05), lower final von Willebrand factor high-molecular-weight:multimer ratio ( P =0.007), and lower final closure time with adenosine-diphosphate ( P =0.02) were associated with the occurrence of new postprocedural microbleeds. In multivariable analysis, a prolonged procedure (odds ratio, 1.22 [95% CI, 1.03-1.73] for every 5 minutes of fluoroscopy time; P =0.02) and postprocedural acquired von Willebrand factor defect (odds ratio, 1.42 [95% CI, 1.08-1.89] for every lower 0.1 unit of high-molecular-weight:multimer ratio; P =0.004) were independently associated with the occurrence of new postprocedural microbleeds. New CMBs were not associated with changes in neurologic functional outcome or quality of life at 6 months., Conclusions: One out of 4 patients undergoing TAVR has CMBs before the procedure and 1 out of 4 patients develops new CMBs. Procedural or antithrombotic management and persistence of acquired von Willebrand factor defect were associated with the occurrence of new CMBs., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT02972008.

Objective: To assess putative risk factors and outcome of multiple and early recurrent cervical artery dissection (CeAD)., Methods: We combined data from 2 multicenter cohorts and compared patients with multiple CeAD at initial diagnosis, early recurrent CeAD within 3 to 6 months, and single nonrecurrent CeAD. Putative risk factors, clinical characteristics, functional outcome, and risk of recurrent ischemic events were assessed., Results: Of 1,958 patients with CeAD (mean ± SD age 44.3 ± 10 years, 43.9% women), 1,588 (81.1%) had single nonrecurrent CeAD, 340 (17.4%) had multiple CeAD, and 30 (1.5%) presented with single CeAD at admission and had early recurrent CeAD. Patients with multiple or early recurrent CeAD did not significantly differ with respect to putative risk factors, clinical presentation, and outcome. In multivariable analyses, patients with multiple or early recurrent CeAD more often had recent infection (odds ratio [OR] 1.81, 95% confidence interval [CI] 1.29-2.53), vertebral artery dissection (OR 1.82, 95% CI 1.34-2.46), family history of stroke (OR 1.55, 95% CI 1.06-2.25), cervical pain (OR 1.36, 95% CI 1.01-1.84), and subarachnoid hemorrhage (OR 2.85, 95% CI 1.01-8.04) at initial presentation compared to patients with single nonrecurrent CeAD. Patients with multiple or early recurrent CeAD also had a higher incidence of cerebral ischemia (hazard ratio 2.77, 95% CI 1.49-5.14) at 3 to 6 months but no difference in functional outcome compared to patients with single nonrecurrent CeAD., Conclusion: Patients with multiple and early recurrent CeAD share similar risk factors, clinical characteristics, and functional outcome. Compared to patients with single nonrecurrent CeAD, they are more likely to have recurrent cerebral ischemia at 3 to 6 months, possibly reflecting an underlying transient vasculopathy., (© 2018 American Academy of Neurology.)

Background: Fractional flow reserve (FFR) is not firmly established as a guide to treatment in patients with acute coronary syndromes (ACS). Primary goals were to evaluate the impact of integrating FFR on management decisions and on clinical outcome of patients with ACS undergoing coronary angiography, as compared with patients with stable coronary artery disease., Methods and Results: R3F (French FFR Registry) and POST-IT (Portuguese Study on the Evaluation of FFR-Guided Treatment of Coronary Disease), sharing a common design, were pooled as PRIME-FFR (Insights From the POST-IT and R3F Integrated Multicenter Registries - Implementation of FFR in Routine Practice). Investigators prospectively defined management strategy based on angiography before performing FFR. Final decision after FFR and 1-year clinical outcome were recorded. From 1983 patients, in whom FFR was prospectively used to guide treatment, 533 sustained ACS (excluding acute ST-segment-elevation myocardial infarction). In ACS, FFR was performed in 1.4 lesions per patient, mostly in left anterior descending (58%), with a mean percent stenosis of 58±12% and a mean FFR of 0.82±0.09. In patients with ACS, reclassification by FFR was high and similar to those with non-ACS (38% versus 39%; P =NS). The pattern of reclassification was different, however, with less patients with ACS reclassified from revascularization to medical treatment compared with those with non-ACS ( P =0.01). In ACS, 1-year outcome of patients reclassified based on FFR (FFR against angiography) was as good as that of nonreclassified patients (FFR concordant with angiography), with no difference in major cardiovascular event (8.0% versus 11.6%; P =0.20) or symptoms (92.3% versus 94.8% angina free; P =0.25). Moreover, FFR-based deferral to medical treatment was as safe in patients with ACS as in patients with non-ACS (major cardiovascular event, 8.0% versus 8.5%; P =0.83; revascularization, 3.8% versus 5.9%; P =0.24; and freedom from angina, 93.6% versus 90.2%; P =0.35). These findings were confirmed in ACS explored at the culprit lesion. In patients (6%) in whom the information derived from FFR was disregarded, a dire outcome was observed., Conclusions: Routine integration of FFR into the decision-making process of ACS patients with obstructive coronary artery disease is associated with a high reclassification rate of treatment (38%). A management strategy guided by FFR, divergent from that suggested by angiography, including revascularization deferral, is safe in ACS., (© 2017 American Heart Association, Inc.)

Objective: In a large series of patients with cervical artery dissection (CeAD), a major cause of ischemic stroke in young and middle-aged adults, we aimed to examine frequencies and correlates of family history of CeAD and of inherited connective tissue disorders., Methods: We combined data from 2 large international multicenter cohorts of consecutive patients with CeAD in 23 neurologic departments participating in the CADISP-plus consortium, following a standardized protocol. Frequency of reported family history of CeAD and of inherited connective tissue disorders was assessed. Putative risk factors, baseline features, and 3-month outcome were compared between groups., Results: Among 1,934 consecutive patients with CeAD, 20 patients (1.0%, 95% confidence interval: 0.6%-1.5%) from 17 families (0.9%, 0.5%-1.3%) had a family history of CeAD. Family history of CeAD was significantly more frequent in patients with carotid location of the dissection and elevated cholesterol levels. Two patients without a family history of CeAD had vascular Ehlers-Danlos syndrome with a mutation in COL3A1. This diagnosis was suspected in 2 additional patients, but COL3A1 sequencing was negative. Two patients were diagnosed with classic and hypermobile Ehlers-Danlos syndrome, one patient with Marfan syndrome, and one with osteogenesis imperfecta, based on clinical criteria only., Conclusions: In this largest series of patients with CeAD to date, family history of symptomatic CeAD was rare and inherited connective tissue disorders seemed exceptional. This finding supports the notion that CeAD is a multifactorial disease in the vast majority of cases., (© 2014 American Academy of Neurology.)

Background: Significant postprocedural aortic regurgitation (AR) is observed in 10% to 20% of cases after transcatheter aortic valve replacement (TAVR). The prognostic value and the predictors of such a complication in balloon-expandable (BE) and self-expandable (SE) TAVR remain unclear., Methods and Results: TAVR was performed in 3195 consecutive patients at 34 hospitals. Postprocedural transthoracic echocardiography was performed in 2769 (92%) patients of the eligible population, and these patients constituted the study group. Median follow-up was 306 days (Q1-Q3=178-490). BE and SE devices were implanted in 67.6% (n=1872) and 32.4% (n=897). Delivery was femoral (75.3%) or nonfemoral (24.7%). A postprocedural AR≥grade 2 was observed in 15.8% and was more frequent in SE (21.5%) than in BE-TAVR (13.0%, P=0.0001). Extensive multivariable analysis confirmed that the use of a SE device was one of the most powerful independent predictors of postprocedural AR≥grade 2. For BE-TAVR, 8 independent predictors of postprocedural AR≥grade 2 were identified including femoral delivery (P=0.04), larger aortic annulus (P=0.0004), and smaller prosthesis diameter (P=0.0001). For SE-TAVR, 2 independent predictors were identified including femoral delivery(P=0.0001). Aortic annulus and prosthesis diameter were not predictors of postprocedural AR for SE-TAVR. A postprocedural AR≥grade 2, but not a postprocedural AR=grade 1, was a strong independent predictor of 1-year mortality for BE (hazard ratio=2.50; P=0.0001) and SE-TAVR (hazard ratio=2.11; P=0.0001). Although postprocedural AR≥grade 2 was well tolerated in patients with AR≥grade 2 at baseline (1-year mortality=7%), it was associated with a very high mortality in other subgroups: renal failure (43%), AR

Background: There is no large report of the impact of fractional flow reserve (FFR) on the reclassification of the coronary revascularization strategy on individual patients referred for diagnostic angiography., Methods and Results: The Registre Français de la FFR (R3F) investigated 1075 consecutive patients undergoing diagnostic angiography including an FFR investigation at 20 French centers. Investigators were asked to define prospectively their revascularization strategy a priori based on angiography before performing the FFR. The final revascularization strategy, reclassification of the strategy by FFR, and 1-year clinical follow-up were prospectively recorded. The strategy a priori based on angiography was medical therapy in 55% and revascularization in 45% (percutaneous coronary intervention, 38%; coronary artery bypass surgery, 7%). Patients were treated according to FFR in 1028/1075 (95.7%). The applied strategy after FFR was medical therapy in 58% and revascularization in 42% (percutaneous coronary intervention, 32%; coronary artery bypass surgery, 10%). The final strategy applied differed from the strategy a priori in 43% of cases: in 33% of a priori medical patients, in 56% of patients undergoing a priori percutaneous coronary intervention, and in 51% of patients undergoing a priori coronary artery bypass surgery. In reclassified patients treated based on FFR and in disagreement with the angiography-based a priori decision (n=464), the 1-year outcome (major cardiac event, 11.2%) was as good as in patients in whom final applied strategy concurred with the angiography-based a priori decision (n=611; major cardiac event, 11.9%; log-rank, P=0.78). At 1 year, >93% patients were asymptomatic without difference between reclassified and nonreclassified patients (Generalized Linear Mixed Model, P=0.75). Reclassification safety was preserved in high-risk patients., Conclusion: This study shows that performing FFR during diagnostic angiography is associated with reclassification of the revascularization decision in about half of the patients. It further demonstrates that it is safe to pursue a revascularization strategy divergent from that suggested by angiography but guided by FFR.

Background and Purpose: Little is known about factors contributing to multiple rather than single cervical artery dissections (CeAD) and their associated prognosis., Methods: We compared the baseline characteristics and short-term outcome of patients with multiple to single CeAD included in the multicenter Cervical Artery Dissection and Ischemic Stroke Patients (CADISP) study., Results: Among the 983 patients with CeAD, 149 (15.2%) presented with multiple CeAD. Multiple CeADs were more often associated with cervical pain at admission (odds ratio [OR], 1.59; 95% confidence interval [CI], 1.10-2.30), a remote history of head or neck surgery (OR, 1.87; 95% CI, 1.16-3.00), a recent infection (OR, 1.71; 95% CI, 1.12-2.61), and cervical manipulation (OR, 2.23; 95% CI, 1.26-3.95). On imaging, cervical fibromuscular dysplasia (OR, 3.97; 95% CI, 2.04-7.74) and the presence of a pseudoaneurysm (OR, 2.91; 95% CI, 1.86-4.57) were more often seen in patients with multiple CeAD. The presence of multiple rather than single CeAD had no effect on functional 3-month outcome (modified Rankin Scale score, ≥3; 12% in multiple CeAD versus 11.9% in single CeAD; OR, 1.20; 95% CI, 0.60-2.41)., Conclusions: In the largest published series of patients with CeAD, we highlighted significant differences between multiple and single artery involvement. Features suggestive of an underlying vasculopathy (fibromuscular dysplasia) and environmental triggers (recent infection, cervical manipulation, and a remote history of head or neck surgery) were preferentially associated with multiple CeAD.

Objective: To examine the import of prior cervical trauma (PCT) in patients with cervical artery dissection (CeAD)., Methods: In this observational study, the presence of and the type of PCT were systematically ascertained in CeAD patients using 2 different populations for comparisons: 1) age- and sex-matched patients with ischemic stroke attributable to a cause other than CeAD (non-CeAD-IS), and 2) healthy subjects participating in the Cervical Artery Dissection and Ischemic Stroke Patients Study. The presence of PCT within 1 month was assessed using a standardized questionnaire. Crude odds ratios (ORs) with 95% confidence intervals (CIs) and ORs adjusted for age, sex, and center were calculated., Results: We analyzed 1,897 participants (n = 966 with CeAD, n = 651 with non-CeAD-IS, n = 280 healthy subjects). CeAD patients had PCT in 40.5% (38.2%-44.5%) of cases, with 88% (344 of 392) classified as mild. PCT was more common in CeAD patients than in non-CeAD-IS patients (ORcrude 5.6 [95% CI 4.20-7.37], p < 0.001; ORadjusted 7.6 [95% CI 5.60-10.20], p < 0.001) or healthy subjects (ORcrude 2.8 [95% CI 2.03-3.68], p < 0.001; ORadjusted 3.7 [95% CI 2.40-5.56], p < 0.001). CeAD patients with PCT were younger and presented more often with neck pain and less often with stroke than CeAD patients without PCT. PCT was not associated with functional 3-month outcome after adjustment for age, sex, and stroke severity., Conclusion: PCT seems to be an important environmental determinant of CeAD, but was not an independent outcome predictor. Because of the characteristics of most PCTs, the term mechanical trigger event rather than trauma may be more appropriate.

Although experimental studies have shown lipoprotein(a) antiangiogenic and antitumoral effects, the association of lipoprotein(a) levels with cancer in population studies remains elusive and poorly documented. The aim of this study was to analyse the relationship between lipoprotein(a) plasma levels and the incidence of cancer over 10 years of follow-up. Data from two French centres of the PRIME cohort were used, representing 5237 men aged 50-59 years and free from a history of cancer at baseline. Data on medical history, socioeconomic and lifestyle factors were obtained by questionnaire. Lipoprotein(a) plasma levels were analysed from fasting blood samples collected at baseline. The relationship between lipoprotein(a) levels and first incident cancer was studied using the multivariate Cox proportional hazards models for all-site and the main-site-specific cancers, adjusted for various potential confounders including age, centre, smoking status and alcohol consumption. During follow-up, 456 new cancers were identified. No significant association was found between lipoprotein(a) and the all-site or main-site-specific cancers (hazard ratios for quartiles 2-4 vs. 1, respectively: 1.24, 1.11, 1.29, P=0.23). However, a higher risk seemed to be observed for highest lipoprotein(a) levels in all sites, lung, colorectal or tobacco/alcohol-related cancers. For prostate cancer, the lowest risk was observed for the highest levels of lipoprotein(a) (P=0.12). In conclusion, no evident association was found between the lipoprotein(a) levels and the incidence of cancer. Nevertheless, a higher cancer risk seemed to be observed for the highest lipoprotein(a) levels. Further research focusing on the lipoprotein(a) qualitative structure, that is, apolipoprotein(a) polymorphism could help clarify this highly complex relation.

Background: Little is known about the risk factors for cervical artery dissection (CEAD), a major cause of ischemic stroke (IS) in young adults. Hypertension, diabetes mellitus, smoking, hypercholesterolemia, and obesity are important risk factors for IS. However, their specific role in CEAD is poorly investigated. Our aim was to compare the prevalence of vascular risk factors in CEAD patients versus referents and patients who suffered an IS of a cause other than CEAD (non-CEAD IS) in the multicenter Cervical Artery Dissection and Ischemic Stroke Patients (CADISP) study., Methods and Results: The study sample comprised 690 CEAD patients (mean age, 44.2 ± 9.9 years; 43.9% women), 556 patients with a non-CEAD IS (44.7 ± 10.5 years; 39.9% women), and 1170 referents (45.9 ± 8.1 years; 44.1% women). We compared the prevalence of hypertension, diabetes mellitus, hypercholesterolemia, smoking, and obesity (body mass index ≥ 30 kg/m²) or overweightness (body mass index ≥ 25 kg/m² and <30 kg/m²) between the 3 groups using a multinomial logistic regression adjusted for country of inclusion, age, and gender. Compared with referents, CEAD patients had a lower prevalence of hypercholesterolemia (odds ratio 0.55; 95% confidence interval, 0.42 to 0.71; P<0.0001), obesity (odds ratio 0.37; 95% confidence interval, 0.26 to 0.52; P<0.0001), and overweightness (odds ratio 0.70; 95% confidence interval, 0.57 to 0.88; P=0.002) but were more frequently hypertensive (odds ratio 1.67; 95% confidence interval, 1.32 to 2.1; P<0.0001). All vascular risk factors were less frequent in CEAD patients compared with young patients with a non-CEAD IS. The latter were more frequently hypertensive, diabetic, and current smokers compared with referents., Conclusion: These results, from the largest series to date, suggest that hypertension, although less prevalent than in patients with a non-CEAD IS, could be a risk factor of CEAD, whereas hypercholesterolemia, obesity, and overweightness are inversely associated with CEAD.

Previous studies have clearly demonstrated the beneficial effect of beta-blockers in patients with stable congestive heart failure (CHF). beta-blockers improve left ventricular ejection fraction (LVEF) and reduce cardiac mortality. However, there is an interindividual variability in the response to these agents. Two studies have suggested a possible impact of some functional betaAR gene polymorphisms on the effects of beta-blockade. The objective of the study is to analyse the association between genetic variations in the beta1 or the beta2 adrenoreceptor (AR) gene and the effects of beta-blockade in patients with stable CHF. We studied 199 consecutive patients with stable CHF not treated with beta-blockers. Before introduction of beta-blockers and 3 months after the maximal tolerated dose was reached, patients underwent an echocardiography and a radionuclide angiography. The beta1ARGly389Arg, beta1ARSer49Gly, beta2ARGly16Arg, beta2ARGln27Glu and beta2ARThr164Ile polymorphisms were determined: beta-blockade resulted in a significant decrease in heart rate, a significant increase in LVEF (from 30+/-10% to 40+/-13%, P<0.0001). There was no association between the five polymorphisms and heart rate or LVEF, either before or after beta-blockade. Heart rate and LVEF responses to beta-blockade were not associated with the beta1AR or the beta2AR polymorphisms. betaAR polymorphisms did not explain the interindividual variability in the response to beta-blockers.

Fish oil is a potent triglyceride (TG)-lowering agent in humans. The goal of the present study was to assess the contribution of decreased triglyceride synthesis and of apoE in mediation of the triglyceride-lowering effect of fish oil. To this end, apoE-deficient mice and wild-type control mice were supplemented with either coconut oil, sunflower oil, or fish oil (20% wt/wt) for 2 weeks. Compared with coconut oil and sunflower oil, fish oil reduced the concentrations of cholesterol and triglycerides in the wild-type mice, whereas it had no effect on cholesterol concentration and it had a triglyceride-raising effect in apoE-deficient mice. The latter was due to increased triglyceride concentrations in the d<1.019 g/mL plasma density fraction. In apoE-deficient mice, but not in wild-type mice, the postprandial triglyceride area under the curve was higher after an intragastric load of fish oil than after a sunflower oil load. These data indicate an impairment of triglyceride metabolism in the fish oil-fed apoE-deficient mice. Compared with coconut oil and sunflower oil, fish oil lowered triglyceride production rates measured with the Triton method in both wild-type (P<0.0001) and apoE-deficient mice (P<0.0001). Similarly, in vitro lipoprotein lipase-mediated lipolysis of VLDL was lowered in the fish oil-fed wild-type and apoE-deficient mice, suggesting an alteration in VLDL lipolysis independent of the mice genotype. In conclusion, fish oil does not decrease triglyceride concentrations in apoE-deficient mice despite reducing triglyceride production rates, suggesting that decreased triglyceride synthesis is not sufficient to lower triglyceride concentrations in mice. ApoE appears to be necessary for fish oil to lower plasma triglyceride concentrations, indicating a critical role of apoE in this process.

Background: We investigated the relationship between variation in the apolipoprotein (apo) AI-CIII-AIV gene cluster and response to an oral glucose test (OGTT) and oral fat load test (OFTT) in the EARSII group of young, healthy male offspring whose fathers had had a myocardial infarction before the age of 55 years (cases, n=407) compared with age-matched controls (n=415). The apoCIII variations examined were C3238G (SstI) in the 3'-UTR, C1100T in exon 3, C-482T in the insulin response element (IRE), and T-2854G in the apoCIII-AIV intergenic region., Methods and Results: The postprandial response was regulated by variation at the T-2854G and C3238G sites. After the OFTT, carriers of the rare alleles had delayed clearance of triglyceride (Tg) levels; G-2854 carriers showed the largest effect on Tg (AUC, 24% greater, P<0.002; peak, 19% greater, P<0.005), and G3238 carriers showed a smaller response (AUC, 13% greater, P<0.05; peak, 13% greater, P=0.03). However, after adjustment for fasting level of Tg, only the effect with the T-2854G remained significant. Variation at the C-482T (IRE) determined response to the OGTT, with carriers of the rare T-482 having significantly elevated glucose (28.7% AUC, P=0.013) and insulin (20.5% AUC, P<0. 01) concentrations., Conclusions: These data suggest that specific genetic variants at the apoCIII gene locus differentially affect postprandial and response to OGTT and suggest a novel mechanism for the effects of variation at this locus on risk for atherosclerosis.

The common C-480T transition in the hepatic lipase (HL) promoter has been shown to be associated with lower HL activity and increased high density lipoprotein (HDL) cholesterol. We examined the frequency and lipid associations of this HL polymorphism in 385 healthy, young (18- to 28-year-old) men whose fathers had had a premature myocardial infarction (designated cases) and 405 age-matched controls. These individuals were participants in the European Atherosclerosis Research Study II postprandial trial, who had been recruited from 11 European countries in 4 regions (the Baltic; United Kingdom; and central and southern Europe). Overall, the frequency of the T allele was 0.207 in controls and 0.244 in cases (P=0.08). The T allele was associated with higher fasting plasma total cholesterol (P<0.01), triglycerides (P<0.01), and HDL cholesterol (P<0.01). The strongest association was found with apolipoprotein (apo) A-I concentration, which was 10% higher in individuals homozygous for the T allele compared with those homozygous for the C allele (P<0.001). This polymorphism had no effect on the rise in plasma triglyceride levels after a fatty meal. However, before and after the fat load was ingested, levels of particles containing both apoC-III and apoB (LpC-III:B) were higher in carriers of the T allele, with homozygotes having 23% and 27% higher levels preprandially and postprandially, respectively, than those homozygous for the C allele (P<0.05). Thus, our results demonstrate that the C-480T polymorphism in the HL promoter is associated with alterations in plasma lipids and lipoproteins and the accumulation of atherogenic LpC-III:B particles.

Treatment with fibrates, a widely used class of lipid-modifying agents, results in a substantial decrease in plasma triglycerides and is usually associated with a moderate decrease in LDL cholesterol and an increase in HDL cholesterol concentrations. Recent investigations indicate that the effects of fibrates are mediated, at least in part, through alterations in transcription of genes encoding for proteins that control lipoprotein metabolism. Fibrates activate specific transcription factors belonging to the nuclear hormone receptor superfamily, termed peroxisome proliferator-activated receptors (PPARs). The PPAR-alpha form mediates fibrate action on HDL cholesterol levels via transcriptional induction of synthesis of the major HDL apolipoproteins, apoA-I and apoA-II. Fibrates lower hepatic apoC-III production and increase lipoprotein lipase--mediated lipolysis via PPAR. Fibrates stimulate cellular fatty acid uptake, conversion to acyl-CoA derivatives, and catabolism by the beta-oxidation pathways, which, combined with a reduction in fatty acid and triglyceride synthesis, results in a decrease in VLDL production. In summary, both enhanced catabolism of triglyceride-rich particles and reduced secretion of VLDL underlie the hypotriglyceridemic effect of fibrates, whereas their effect on HDL metabolism is associated with changes in HDL apolipoprotein expression.

The biological role of the very low density lipoprotein receptor (VLDL-R) in humans is not yet elucidated. This cellular receptor binds apolipoprotein E (apoE)-containing lipoparticles and is mainly expressed in peripheral tissues. The VLDL-R gene contains a polymorphic triplet (CGG) repeat located 19 bp upstream of the initiation codon. We explored the allelic distribution of this repeat in 1384 subjects of European Caucasian origin, 609 of them surviving a myocardial infarction. Six alleles corresponding to 5, 6, 7, 8, 9, and 11 repeats were detected in this population. The alleles 5, 8, and 9 were the most frequent, with frequencies of 0.413, 0.275, and 0.292, respectively. No association was found between the VLDL-R polymorphism and myocardial infarction. In controls without lipid lowering treatment, a statistically significant interaction between VLDL-R genotype and apoE phenotype was found for plasma triglycerides (P < .04), suggesting a gene-gene interaction. There was also a main effect of the VLDL-R polymorphism on LpE:B and LpA-I. The VLDL-R 9 allele was associated with lower levels of plasma LpE:B (P < .05) and higher concentrations of plasma LpA-I (P < .01) than the other alleles. These results suggest that VLDL-R has a modest influence on circulating lipoproteins in humans.

Apolipoprotein A-I-containing lipoproteins represent a heterogeneous group of lipoparticles. Recent studies suggest that a specific subpopulation within the lipoprotein (AI) subclass may be more effective than other lipoproteins in promoting cholesterol efflux from cells and in the different steps of reverse cholesterol transport. This review describes the different apolipoprotein A-I-containing HDL subfractions, their role in reverse cholesterol transport, and their metabolic interconversions and relationship with lipoprotein-modifying enzymes.