Aj van Boven

Effects of the high-density lipoprotein mimetic agent CER-001 on coronary atherosclerosis in patients with acute coronary syndromes: a randomized trial†

Aim High-density lipoproteins (HDLs) have several potentially protective vascular effects. Most clinical studies of therapies targeting HDL have failed to show benefits vs. placebo. Objective To investigate the effects of an HDL-mimetic agent on atherosclerosis by intravascular ultrasonography (IVUS) and quantitative coronary angiography (QCA). Design and setting A prospective, double-blinded, randomized trial was conducted at 51 centres in the USA, the Netherlands, Canada, and France. Intravascular ultrasonography and QCA were performed to assess coronary atherosclerosis at baseline and 3 (2–5) weeks after the last study infusion. Patients Five hundred and seven patients were randomized; 417 and 461 had paired IVUS and QCA measurements, respectively. Intervention Patients were randomized to receive 6 weekly infusions of placebo, 3 mg/kg, 6 mg/kg, or 12 mg/kg CER-001. Main outcome measures The primary efficacy parameter was the nominal change in the total atheroma volume. Nominal changes in per cent atheroma volume on IVUS and coronary scores on QCA were also pre-specified endpoints. Results The nominal change in the total atheroma volume (adjusted means) was −2.71, −3.13, −1.50, and −3.05 mm3 with placebo, CER-001 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively (primary analysis of 12 mg/kg vs. placebo: P = 0.81). There was also no difference among groups for the nominal change in per cent atheroma volume (0.02, −0.02, 0.01, and 0.19%; nominal P = 0.53 for 12 mg/kg vs. placebo). Change in the coronary artery score was −0.022, −0.036, −0.022, and −0.015 mm (nominal P = 0.25, 0.99, 0.55), and change in the cumulative coronary stenosis score was −0.51, 2.65, 0.71, and −0.77% (compared with placebo, nominal P = 0.85 for 12 mg/kg and nominal P = 0.01 for 3 mg/kg). The number of patients with major cardiovascular events was 10 (8.3%), 16 (13.3%), 17 (13.7%), and 12 (9.8%) in the four groups. Conclusion CER-001 infusions did not reduce coronary atherosclerosis on IVUS and QCA when compared with placebo. Whether CER-001 administered in other regimens or to other populations could favourably affect atherosclerosis must await further study. Name of the trial registry: Clinicaltrials.gov; Registrys URL: http://clinicaltrials.gov/ct2/show/NCT01201837?term=cer-001&rank=2; Trial registration number: NCT01201837.

Microalbuminuria modifies the mortality risk associated with electrocardiographic ST-T segment changes

OBJECTIVES We sought to investigate whether microalbuminuria, a proposed marker of generalized vascular damage, enhances the prognostic value of ST-T segment changes for all-cause and cardiovascular mortality in the general population. BACKGROUND ST-T segment changes on the rest electrocardiogram (ECG) predict mortality in the general population. However, the excess risk seems to be low, particularly in nonhospitalized populations with a low cardiovascular risk profile. METHODS In a population of 7,330 male and female subjects, a total of 89 deaths (1.2%) occurred during a median three-year follow-up. In 69 of these, the cause of death was obtained from the Central Bureau of Statistics: 25 subjects died of cardiovascular causes (36%). Using computerized Minnesota coding, ST-T segment changes were coded as 4.1-4 and 5.1-4. Microalbuminuria was defined as a urinary albumin excretion of 30 to 300 mg per 24 h. RESULTS The combination of ST-T segment changes and microalbuminuria showed a higher hazard ratio (HR) for all-cause mortality (HR 8.6 [95% confidence interval [CI] 4.8 to 15.2, p < 0.0001), as compared with ST-T segment changes in the absence of microalbuminuria (HR 1.3 [95% CI 0.7 to 2.5]), which was independent of other cardiovascular risk factors (HR 3.3 [95% CI 1.5 to 7.1], p = 0.002). The combination showed a higher HR when only cardiovascular deaths were taken into account, as compared with all-cause mortality (HR 24.5 [95% CI 7.9 to 76.0], p < 0.0001), which also counted for ST-T segment changes alone (HR 4.4 [95% CI 1.4 to 14.5], p = 0.02). After controlling for other risk factors, the HRs were 10.4 (95% CI 2.5 to 43.6, p = 0.001) for the combination and 2.7 (95% CI 0.6 to 12.3) for ST-T segment changes alone. CONCLUSIONS This study suggests that, in subjects with ST-T segment changes on their rest ECG, microalbuminuria could identify those at increased risk of all-cause and cardiovascular mortality.

Increased risk for ischaemic events is related to combined RAS polymorphism

OBJECTIVE To determine whether the angiotensin converting enzyme (ACE) and the angiotensin II type 1 receptor (AT1R A1166C) gene polymorphism interact to increase the risk of ischaemic events, and whether this can be explained by the progression of angiographically defined coronary atherosclerosis. DESIGN Prospective defined substudy of the lipid lowering regression trial (REGRESS). SETTING University hospital. PATIENTS 885 male patients with stable coronary artery disease. MAIN OUTCOME MEASURES Incidence of ischaemic events during a two year follow up; serial quantitative coronary arteriography (mean segment diameter and minimum obstruction diameter) at baseline and after two years. RESULTS Patients who carried both the ACE-DD and AT1R-CC genotype had significantly more ischaemic events during the two year follow up than those carrying other genotype combinations (p = 0.035, Mantel-Haenszel test for linear association). There was no association between the two genotypes and mean segment diameter or minimum obstruction diameter at baseline or after two years. CONCLUSIONS The suggestion that ACE-DD and AT1R-CC genotypes interact to increase the risk of ischaemic events is confirmed. However, this increased risk was not accompanied by increased progression of angiographically defined coronary atherosclerosis.

An integrated evaluation of endothelial constitutive nitric oxide synthase polymorphisms and coronary artery disease in men

In the present study, we sought to evaluate the role of three polymorphisms in the ecNOS (endothelial constitutive nitric oxide synthase) gene in relation to the existence, severity and progression of CAD (coronary artery disease), MI (myocardial infarction) and the occurrence of ischaemia in a predominantly Caucasian population. Patients with CAD (n = 760) and age- and sex-matched population-based controls (n = 691) were genotyped for the -786T/C, E/D298 and 4a/b polymorphisms. Patients were randomized to pravastatin (40 mg) or placebo. Progression of atherosclerosis was evaluated by sequential angiography. Functionality was assessed by ST segment analysis of ambulant ECGs. The E298 (P = 0.003) and 4a (P = 0.001) alleles were associated with CAD. Furthermore, E298 (P = 0.009) and -786T (P = 0.022) alleles were associated with previous MI among patients, predominantly smokers. D/D298 homozygotes, but not -786T/C or 4a/4b mutants, had longer-lasting ischaemia than others (P < 0.05). We found no differences in progression of atherosclerosis, irrespective of pravastatin use. We conclude that the E/D298 polymorphism is most consistently associated with CAD, but not with progression of atherosclerosis. The E allele is associated with CAD and MI, whereas the D allele is associated with ischaemia.

Safety evaluation of routine intracoronary acetylcholine infusion in patients undergoing a first diagnostic coronary angiogram.

Background Recent findings imply prognostic significance of intracoronary acetylcholine infusion for endothelial function testing. We evaluated whether routine use of this test in coronary angiography patients is safe. Methods Patients undergoing a first diagnostic coronary angiography were selected to receive intracoronary acetylcholine for endothelial function evaluation. The relation between adverse reactions during infusion and risk factors was analyzed with a logistic regression model. Included in the multiple logistic regression model were the variables with a univariate P value < 0.20. Results Adverse reactions occurred in 16% (49/299) of the patients. This included two life-threatening events caused by occlusive spasm and flow limitation in the left coronary artery. Other adverse events were chest pain (n = 38), AV block or sinus bradycardia (n = 10), dyspnea (n = 3). Adverse reactions were more likely to occur in patients younger than 60 years of age (relative risk, 5.6 [2.2–14.3]). Conclusion Intracoronary acetylcholine infusion is safe, but may lead to serious adverse reactions. Care should be taken especially in patients younger than 60 years of age. Routine use of acetylcholine infusion can thus only be justified if it has important prognostic significance. This has to be proven further in large prospective studies.

Genetic manipulation of the restricted facultative methylotroph Hyphomicrobium X by the R-plasmid-mediated introduction of the Escherichia coli pdh genes

The inability of Hyphomicrobium X to grow on compounds such as pyruvate and succinate is most likely due to the absence of a functional pyruvate dehydrogenase (PDH) complex. Further support for this was sought by studying the effect of the introduction of the Escherichia coli pdh genes in Hyphomicrobium X on the pattern of substrate utilization by the latter organism. These genes were cloned by in vivo techniques using the broad-host range conjugative plasmid RP4: :Mucts. Plasmid RP4 derivatives containing pdh genes were selected by their ability to complement a pyruvate dehydrogenase deletion mutant of E. coli, strain JRG746 recA (ace-1pd) Δ18. The plasmids thus obtained could be transferred through an intermediary host (C600 recA), selecting only for an antibiotic resistance coded for by RP4 and back into JRG746 or other E. coli pdh mutants, upon which they still conferred the wild type phenotype. Enzyme assays showed that the latter strains, when carrying plasmid RP4′ pdh1 also possessed PDH complex activity. Conjugation between the auxotrophic E. coli JRG746 (RP4′ pdh1) strain and Hyphomicrobium X on pyruvate minimal agar gave rise to progeny which, on the basis of its morphology (stalked bacteria), their ability to grow on C1-compounds and to denitrify (now also with pyruvate) were identified as hyphomicrobia. This Hyphomicrobium X transconjugant was also able to grow in minimal medium with succinate, but no other novel growth substrates have been identified so far. An analysis of protein extracts with 2-dimensional gel electrophoresis indicated that Hyphomicrobium X and JRG746 only synthesized all three components of the PDH complex when carrying plasmid RP4′ pdh1. These results are compatible with the suggested significance of the lack of a functional PDH complex in wild type Hyphomicrobium X.

Association between angiographic culprit lesion and out-of-hospital cardiac arrest in ST-elevation myocardial infarction patients

BACKGROUND Factors related to the occurrence of out-of-hospital cardiac arrest (OHCA) in ST-elevation myocardial infarction (STEMI) are still poorly understood. The current study sought to compare STEMI patients presenting with and without OHCA to identify angiographic factors related to OHCA. METHODS This multicenter registry consisted of consecutive STEMI patients, including OHCA patients with return-of-spontaneous circulation. Patients were treated with primary percutaneous coronary intervention (PCI) and therapeutic hypothermia when indicated. Outcome consisted of in-hospital neurological recovery, scored using the Cerebral Performance Categories (CPC) scale, and 1-year survival. Logistic regression was used to identify factors associated with OHCA and survival was displayed with Kaplan-Meier curves and compared using log rank tests. RESULTS In total, 224 patients presented with OHCA and 3259 without OHCA. Average age was 63.3 years and 75% of patients were male. OHCA occurred prior to ambulance arrival in 68% of patients and 48% required intubation. Culprit lesion was associated with OHCA: risk was highest for proximal left coronary lesions and lowest for right coronary lesions. Also, culprit lesion determined the risk of cardiogenic shock and sub-optimal reperfusion after PCI, which were strongly related to survival after OHCA. Neurological recovery was acceptable (CPC≤2) in 77.1% of OHCA patients and did not differ between culprit lesions. CONCLUSIONS In the present STEMI population, coronary culprit lesion was associated with the occurrence of OHCA. Moreover, culprit lesion influenced the risk of cardiogenic shock and success of reperfusion, both of which were related to prognosis of OHCA patients.

Coronary vasomotor response is related to the angiographic extent of coronary sclerosis in patients with stable angina pectoris

Disturbed vasomotor function in coronary arteries has clinical importance in early stages of coronary artery disease (CAD), as it may contribute to the potential risk for an ischaemic coronary event. In the present study, we have investigated the relationship between coronary vasomotor function and the extent of CAD. The response to acetylcholine and nitrate infusion was assessed by quantitative coronary angiography. The extent of CAD was categorized into two groups: minor CAD (normal coronary arteries and vessel wall irregularities) and significant CAD (one-, two- and three-vessel disease). A total of 277 patients with stable angina pectoris, referred for a first diagnostic coronary angiography, were eligible for analysis (mean age 57 years, 61% male). The response to nitrate was significantly impaired in patients with significant CAD ( P <0.001). On the other hand, the response to acetylcholine was not different between the two groups ( P =0.12); however, a trend between the response to acetylcholine and the extent of CAD was observed in patients without a previous infarction ( P =0.07), which was a significant interaction variable. Furthermore, a significant relationship between coronary vasomotor response and the number of cardiovascular risk factors was observed ( P <0.05). In conclusion, in a heterogeneous group of patients, coronary vasomotor function measured by nitrate infusion was more strongly associated with the extent of CAD and the number of risk factors than the response to acetylcholine. These data suggest that, in patients with advanced atherosclerosis or multiple risk factors, the vasomotor dysfunction is not solely restricted to the endothelium.

Multilink stent promotes less platelet and leukocyte adhesion than a traditional stainless steel stent: an in vitro experimental study.

Background Platelet and leukocyte deposition onto metallic struts can be a crucial factor in the outcome of a coronary stenting procedure. By means of an in vitro, closed-loop circulation model, we aimed to assess blood-stent interaction patterns for a new stainless steel stent (MultiLink, Guidant Nederland BV, Nieuwegein, the Netherlands). Methods The effect of MultiLink (n=20) on blood cells and blood activation was studied by biochemical assays. Platelet and leukocyte adhesion to MultiLink were studied by immunofluorocytometric assays (anti-GpIIIa [CD 61] and anti-CD11b labeled antibodies, respectively), and by scanning electron microscopy. MultiLink was compared with empty circuits (n=20) and to the Palmaz Schatz stent (n=20). Experiments were performed both in the presence and in the absence of an antiplatelet agent (15 μg/mL of indomethacin). Results No significant effect on blood cells and blood activation was demonstrated for MultiLink. Antiplatelet treatment significantly reduced platelet adhesion to MultiLink (from 3.78±1.28 to 2.23±0.57x106 count per second [cps]/stent) but not to the Palmaz Schatz stent (from 4.11±0.31 to 5.02±1.29x106 cps/stent)(P=0.011). Leukocyte adhesion to MultiLink was significantly less than adhesion to the Palmaz Schatz stent (7.95±1.59 vs. 9.16±1.36x106 cps/stent, respectively; P=0.016), regardless of the presence of antiplatelet treatment. Conclusions When compared with a traditional stainless steel stent, MultiLink seems to have features of improved hemocompatibility, and single antiplatelet treatment is proposed as the treatment of choice to prevent platelet deposition.

Eptifibatide and abciximab exhibit equivalent antiplatelet efficacy in an experimental model of stenting in both healthy volunteers and patients with coronary artery disease

Platelet deposition and aggregation are the major determinants of acute thrombosis in coronary stents. We aimed to compare the antiplatelet efficacy of different treatments—glycoprotein (Gp) IIb/IIIa inhibitors and conventional antiaggregants—in an experimental model for stenting. Blood samples were obtained from patients with coronary artery disease (n = 15) and healthy volunteers (n = 8) and incubated either with eptifibatide (2.0 &mgr;g/ml), abciximab (3.0 &mgr;g/ml), indomethacin (15 &mgr;g/ml), or saline. Platelet adenosine diphosphate–induced aggregation in whole blood was assessed for all groups. Blood was also tested in an experimental circulation model containing metallic probes, on which platelet deposition in shear flow conditions was assessed by means of fluorescent-labeled platelet-specific (anti-GpIIIa and Ib) antibodies. Eptifibatide and abciximab, in comparison with indomethacin and no treatment, significantly reduced platelet aggregation (0, 0, 4, and 3 arbitrary units [AU], respectively; p < 0.001), anti-GpIIIa (2.25, 1.83, 11.24, and 13.42 counts per second [cps]/mg, respectively; p < 0.001), and anti-GpIb binding (0.61, 0.61, 1.00, and 1.83 cps/mg, respectively; p < 0.001). Anti-GpIIIa and anti-GpIb binding were significantly correlated (R = 0.36; p < 0.01). Patients showed a higher anti-GpIIIa, but not anti-GpIb binding, than controls (8.43 versus 3.33 cps/mg; p < 0.01), irrespective of treatment. In conclusion, eptifibatide and abciximab show equivalent in vitro antiplatelet efficacy, superior to that of indomethacin. Given the occurrence of GpIIb/IIIa platelet overexpression in the course of coronary artery disease, an extended use of GpIIb/IIIa inhibitors may be proposed to prevent acute thrombosis during routine coronary stenting.