Relationship between fermented dairy consumption, circulating short-chain acylcarnitines and angiographic severity of coronary artery disease

BACKGROUND AND AIMS

Current epidemiologic data suggest beneficial cardiovascular effects of fermented dairy products (FDP). However, the relationship between FDP consumption and angiographic coronary status has not been previously studied. Furthermore, the role of novel metabolomic biomarkers of cardiovascular risk in this context is unclear. We hypothesize that short-chain acylcarnitines (SCA) reflect the link between FDP intake and angiographic extent of stable coronary artery disease (CAD).

METHODS AND RESULTS

We recruited 1185 patients admitted for suspected CAD [median age 62 years (interquartile range: 54-69); 714 men (60.3%)]. Prior to coronary angiography, each patient completed a validated Food Frequency Questionnaire. In addition, venous blood was collected from each patient for whole blood metabolomic analysis, using targeted mass-spectrometry. CAD was defined by the presence of ≥1 coronary stenosis ≥50%. Patients with CAD (n = 441) reported lower median FDP intake [86.8 g/day (IQR: 53.4-127.6)] than patients without CAD [n = 744; 103.9 g/day (IQR: 62.9-152.7); p < 0.001]. Upon adjustment for relevant confounders, increased circulating SCA, particularly level of acetylcarnitine (C2) associated with both higher CAD probability [SCA:β(SE) = 0.584 (0.235), p = 0.013; C2:β(SE) = 0.575 (0.242), p = 0.017] and decreased FDP consumption [SCA:β/100 g FDP-increment/day (SE) = -0.785 (0.242), p = 0.001; C2:β(SE) = -0.560 (0.230), p = 0.015]. By mediation analysis, neither SCA nor C2 showed relevant mediator effect linking FDP consumption to the risk of CAD.

CONCLUSION

Increased consumption of fermented milk was associated with lower prevalence of CAD and correlated inversely with circulating SCA, in particular with acetylcarnitine. No substantial mediator effect of SCA linking fermented milk intake with risk of CAD was found.

CLINICAL TRIAL REGISTRY

NCT00497887.

Impact of Leaflet Laceration on Transcatheter Aortic Valve-in-Valve Washout: BASILICA to Solve Neosinus and Sinus Stasis

OBJECTIVES

The aim of this study was to evaluate any potential leaflet washout benefits after bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (BASILICA) in transcatheter valve-in-valve (ViV) in the context of leaflet thrombosis.

BACKGROUND

Leaflet thrombosis after transcatheter aortic valve replacement is secondary to flow stasis in both the sinus and neosinus. Strategies to improve washout and ameliorate neosinus and sinus flow velocities may have the potential to mitigate the occurrence of clinical and subclinical leaflet thrombosis.

METHODS

A 23-mm Edwards SAPIEN 3 and a 26-mm Medtronic Evolut were deployed in a 23-mm transparent surgical aortic valve model before and after leaflet laceration. The valves were placed in the aortic position of a pulse duplicator flow loop. Particle image velocimetry was performed to quantify sinus flow hemodynamic status. A tracing fluorescent dye was injected to evaluate the number of cycles to washout in both regions of interest.

RESULTS

The leaflet laceration procedure led to an increase in the velocities in the sinus and the neosinus by 50% for Evolut ViV and 61.9% for SAPIEN 3 ViV. In addition, leaflet laceration led to a reduction in overall cycles to washout in the neosinus by at least 56% with the Evolut and 54.5% with the SAPIEN 3 and in the sinus by at least 16.7% with the Evolut and 60.8% with the SAPIEN.

CONCLUSIONS

Leaflet laceration using a BASILICA-type approach may hold the potential to mitigate neosinus and sinus flow stasis. Controlled in vivo trials are necessary to establish the potential benefit of BASILICA to reduce the occurrence of leaflet thrombosis.

From Detecting the Vulnerable Plaque to Managing the Vulnerable Patient: JACC State-of-the-Art Review

The past decades have seen tremendous progress on elucidating mechanisms leading to acute coronary syndrome and sudden cardiac death. Pathology and imaging studies have identified features of coronary atherosclerosis that precede acute coronary events. However, many factors influence the risk of adverse events from coronary atherosclerotic disease and available data support our transition from focusing on individual "vulnerable plaque," coronary arterial stenosis, and inducible myocardial ischemia to understanding coronary heart disease as multifactorial, chronic disease. The concept of the vulnerable patient has evolved, with the atheroma burden, its metabolic activity, and the disposition to vascular thrombosis building a platform for assessing central aspects of coronary heart disease. In turn, this model has directed us to a focus on controlling the activity of atherosclerotic disease and on modifying the susceptibility of vascular thrombosis which has led to reduced morbidity and mortality from coronary heart disease.

Bioprosthetic Valve Leaflet Displacement During Valve-in-Valve Intervention: An Ex Vivo Bench Study

OBJECTIVES

The aim of this study was to examine the effect of different transcatheter heart valves (THVs) on valve leaflet displacement when deployed within bioprosthetic surgical valves and, thereby, risk for coronary obstruction.

BACKGROUND

Coronary obstruction is a potentially devastating complication during valve-in-valve (ViV) transcatheter aortic valve replacement. Strategies such as provisional stenting and intentional bioprosthetic valve leaflet laceration have been developed to mitigate this risk. Alternatively, the use of a THV that retracts the bioprosthetic leaflet away from the coronary ostium may prevent coronary obstruction.

METHODS

A 25-mm J-Valve, a 26-mm Evolut Pro, and a 23-mm JenaValve were implanted into both a 25-mm Trifecta surgical valve and a 25-mm Mitroflow surgical valve. A 23-mm and a 26-mm SAPIEN 3 were deployed into the Trifecta and Mitroflow, respectively. Displacement of the surgical valve leaflets (retraction vs. expansion) was measured with implantation of each THV by measuring displacement angle and maximal displacement distance.

RESULTS

Within both the Trifecta and Mitroflow valves, implantation of the J-Valve and JenaValve resulted in retraction of the surgical valve leaflets, and placement of the Evolut Pro and SAPIEN 3 resulted in tubular expansion of the surgical valve leaflets. There were significant differences in displacement angles and distances between both the J-Valve and JenaValve and the SAPIEN 3 and Evolut Pro (p < 0.0001).

CONCLUSIONS

ViV implantation with new-generation THVs that directly interact with bioprosthetic valve leaflets results in surgical valve leaflet retraction. This might mitigate the risk for coronary obstruction in selected cases of ViV transcatheter aortic valve replacement and also facilitate coronary reaccess after ViV TAVR.

The BASILICA Trial: Prospective Multicenter Investigation of Intentional Leaflet Laceration to Prevent TAVR Coronary Obstruction

OBJECTIVES

The BASILICA (Bioprosthetic or native Aortic Scallop Intentional Laceration to prevent Iatrogenic Coronary Artery obstruction during TAVR) investigational device exemption trial was a prospective, multicenter, single-arm safety and feasibility study.

BACKGROUND

Coronary artery obstruction is a rare but devastating complication of transcatheter aortic valve replacement (TAVR). Current stent-based preventative strategies are suboptimal. Bioprosthetic or native aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction during TAVR (BASILICA) is a novel transcatheter technique performed immediately before TAVR to prevent coronary artery obstruction.

METHODS

Subjects with severe native or bioprosthetic aortic valve disease at high or extreme risk for surgery, and at high risk of coronary artery obstruction, were included. The primary success endpoint was successful BASILICA and TAVR without coronary obstruction or reintervention. The primary safety endpoint was freedom from major adverse cardiovascular events. Data were independently monitored. Endpoints were independently adjudicated. A core laboratory analyzed computed tomography images.

RESULTS

Between February 2018 and July 2018, 30 subjects were enrolled. Primary success was met in 28 (93%) subjects. BASILICA traversal and laceration was successful in 35 of 37 (95%) attempted leaflets. There was 100% freedom from coronary obstruction and reintervention. Primary safety was met in 21 (70%), driven by 6 (20%) major vascular complications related to TAVR but not BASILICA. There was 1 death at 30 days. There was 1 (3%) disabling stroke and 2 (7%) nondisabling strokes. Transient hemodynamic compromise was rare (7%) and resolved promptly with TAVR.

CONCLUSIONS

BASILICA was feasible in both native and bioprosthetic valves. Hemodynamic compromise was uncommon. Safety was acceptable and needs confirmation in larger studies. BASILICA appears effective in preventing coronary artery obstruction from TAVR in subjects at high risk.

Cardiac CT to assess the risk of coronary compression in patients evaluated for percutaneous pulmonary valve implantation

BACKGROUND

Coronary compression (CC) is a life threatening complication that can occur during percutaneous pulmonary valve implantation (PPVI). We describe our experience using cardiac CT prior to PPVI to identify patients at high CC-risk due to a close relationship between the coronary arteries and pulmonary trunk (PT).

METHODS

A retrospective evaluation of candidates for PPVI who underwent CT prior to the procedure was done. Measurements of PT were performed using double oblique reconstructed images, with special attention to the stenotic tract of the PT. The analysis of coronary arteries included detection of anomalies of origin and course and assessment of their relationship with the PT, measuring the minimum distance between the coronary artery and the intended site of the future percutaneous valve implantation.

RESULTS

CT analysis was performed for 52 patients. Thirty patients underwent PPVI after CT and 22 didn't. In 6/22 cases the reason not to receive a PPVI was high CC-risk detected at CT. In 6 other patients CT detected an intermediate CC-risk but the test balloon performed during angiography prior to valve placement was safe and the patients successfully underwent the procedure. None of the patients deemed as no CC-risk at CT had CC during PPVI.

CONCLUSION

CT can detect patients with high and intermediate CC-risk and therefore may identify which patients are unlikely to undergo successful PPVI and those who need a careful analysis with balloon testing. CT can also rule out CC-risk identifying those patients in which balloon inflation testing could be omitted.

Non-ST-elevation myocardial infarction outcomes in patients with type 2 diabetes with non-obstructive coronary artery stenosis: Effects of incretin treatment

There are insufficient data on the prognosis and management of people with type 2 diabetes who experience a non-obstructive coronary artery stenosis (NOCS)-non-ST-elevation myocardial infarction (NSTEMI) event. We evaluated the 12-month prognosis of patients with diabetes and NOCS (20%-49% luminal stenosis) who experience a first NSTEMI as compared with patients without diabetes. In addition, we investigated the 12-month prognosis in patients with diabetes and NSTEMI-NOCS previously treated with incretin-based therapy compared with a matched cohort of patients with NSTEMI-NOCS never treated with such therapy. We categorized the patients with diabetes as current incretin users (6 months' treatment with glucagon-like peptide-1 agonists or dipeptidyl peptidase-4 inhibitors) and non-users of incretins. The endpoint was all-cause mortality, cardiac death, recurrent acute coronary syndrome (ACS), and heart failure. The unadjusted Kaplan-Meier analysis, and a risk-adjusted hazard analysis showed that, all-cause mortality, cardiac death, readmission for ACS and heart failure rates during the 12-month follow-up were higher in patients with diabetes and NOCS-NSTEMI than in those with NOCS-NSTEMI without diabetes. Among the patients with diabetes, the current incretin users had a significantly lower rate of all-cause mortality, cardiac death and readmission for ACS at 12 months. In patients with type 2 diabetes and NOCS-NSTEMI, we observed a higher incidence of 1-year mortality and adverse cardiovascular outcomes, as compared with patients without diabetes with NOCS-NSTEMI. In people with diabetes, non-users of incretins had a worse prognosis than current incretin users.

Effect of endovascular coronary low-level laser therapy during angioplasty on the release of endothelin-1 and nitric oxide

BACKGROUND

Nitric oxide (NO) and endothelin-1 are potentially significant factors contributing to the pathogenesis of post-angioplasty restenosis. It may be postulated that low-level laser therapy (LLLT) can favorably influence the process of restenosis by affecting those factors.

OBJECTIVES

The aim of the study was to evaluate the effect of LLLT applied during percutaneous coronary intervention (PCI) on the factors participating in the homeostasis of vascular tone - NO and endothelin-1.

MATERIAL AND METHODS

In a randomized, prospective study of 52 subjects undergoing PCI, an additional 808 nm intravascular LLLT was applied at a dose of 9 J/cm2 in the lesion part. The control group was 49 subjects with PCI only. We assessed the concentration of nitrites/nitrates reflecting NO metabolism as well as endothelin-1 in both groups before PCI, and at 6 h, 12 h and 1 month after the procedure. In addition, half a year after PCI, a follow-up angiography was performed.

RESULTS

Statistically higher nitrite/nitrate concentrations were observed in the laser group as compared to the control group in all tests except the pre-PCI assays. Endothelin-1 levels were significantly higher in the laser group 6 h after PCI with a significant decrease in subsequent tests, which was not observed in the control group. The restenosis rate was 15.0% in the laser group and 32.4% in the control group (however the difference was not statistically significant).

CONCLUSIONS

LLLT applied during the PCI procedure can influence the process of restenosis by modifying NO and endothelin-1 concentrations.

Randomised, double-blind, placebo-controlled study investigating the effects of inorganic nitrate on vascular function, platelet reactivity and restenosis in stable angina: protocol of the NITRATE-OCT study

INTRODUCTION

The mainstay treatment for reducing the symptoms of angina and long-term risk of heart attacks in patients with heart disease is stent implantation in the diseased coronary artery. While this procedure has revolutionised treatment, the incidence of secondary events remains a concern. These repeat events are thought to be due, in part, to continued enhanced platelet reactivity, endothelial dysfunction and ultimately restenosis of the stented artery. In this study, we will investigate whether a once a day inorganic nitrate administration might favourably modulate platelet reactivity and endothelial function leading to a decrease in restenosis.

METHODS AND DESIGN

NITRATE-OCT is a double-blind, randomised, single-centre, placebo-controlled phase II trial that will enrol 246 patients with stable angina due to have elective percutaneous coronary intervention procedure with stent implantation. Patients will be randomised to receive 6 months of a once a day dose of either nitrate-rich beetroot juice or nitrate-deplete beetroot juice (placebo) starting up to 1 week before their procedure. The primary outcome is reduction of in-stent late loss assessed by quantitative coronary angiography and optical coherence tomography at 6 months. The study is powered to detect a 0.22±0.55 mm reduction in late loss in the treatment group compared with the placebo group. Secondary end points include change from baseline assessment of endothelial function measured using flow-mediated dilation at 6 months, target vessel revascularisation (TVR), restenosis rate (diameter>50%) and in-segment late loss at 6 months, markers of inflammation and platelet reactivity and major adverse cardiac events (ie, myocardial infarction, death, cerebrovascular accident, TVR) at 12 and 24 months.

ETHICS AND DISSEMINATION

The study was approved by the Local Ethics Committee (15/LO/0555). Trial results will be published according to the CONSORT statement and will be presented at conferences and reported in peer-reviewed journals.

TRIAL REGISTRATION NUMBERS

NCT02529189 and ISRCTN17373946, Pre-results.

Associations between antiretroviral use and subclinical coronary atherosclerosis

OBJECTIVES

HIV infection is associated with increased prevalence of subclinical coronary plaque. The extent to which such plaque reflects effects of HIV infection or effects of long-term antiretroviral therapy (ART) use remains unclear and was the goal of this analysis.

DESIGN AND METHODS

We compared the prevalence and extent of coronary plaque and stenosis between users of specific ART drugs or drug classes using coronary computed tomography (CT) among HIV-infected men in the Multicenter AIDS Cohort Study. To account for time-dependent confounders, including cardiovascular disease risk factors and time-varying reasons for using specific treatments, we conducted fully adjusted logistic and linear models with inverse probability of treatment weighting.

RESULTS

There were 618 men who underwent noncontrast coronary CT; 450 also underwent coronary CT angiography. At the time of scanning, 81% had undetectable plasma HIV RNA. In fully adjusted models, cumulative use of zidovudine, abacavir, darunavir, and protease inhibitors as a drug class were inconsistently associated with specific forms of plaque presence or extent.

CONCLUSION

Among virally suppressed HIV-infected men with extensive ART exposure, no consistent associations between use of specific ART drugs and both subclinical coronary plaque presence and extent were apparent. Our findings support the hypothesis that, among virally suppressed persons, type of ART used is not in general a major determinant of subclinical coronary plaque risk.

Associations Between Target Lesion Restenosis and Drug-Eluting Balloon Use: An Observational Study

Percutaneous coronary interventions (PCIs) with drug-eluting balloons (DEBs) have emerged as an adjunctive treatment for in-stent restenosis (ISR) lesions. However, recurrent restenosis still occurs following DEB use. Our study aimed to identify the associations of target lesion restenosis following DEB use over a 1-year clinical follow-up.Between November 2011 and May 2014, 246 patients were diagnosed with coronary artery ISR in our hospital. A total of 335 coronary ISR lesions were treated with DEBs. The 1-year patent coronary artery group was defined as those with negative noninvasive examinations and no clinical symptoms, or those with no angiographic restenosis. The 1-year current restenosis group was defined as those with angiographic restenosis. Clinical results were compared between 2 groups. Univariate and multivariate cox regression analyses were performed to identify the associations of target lesion restenosis following DEB use.Patients' average age was 64.96 ± 10.68 years, and 77.2% were men. Non-ST segment elevation myocardial infarction was more frequent as the clinical presentation in the 1-year current restenosis group, whereas stable angina was more frequent in the 1-year patent coronary artery group. The 1-year current restenosis group exhibited higher percentages of comorbidities, including hypertension, diabetes, prior myocardial infarction, heart failure, prior coronary artery bypass grafting, and end-stage renal disease (ESRD). Regardless of ostial ISR or nonostial ISR, the results of drug-eluting stent ISR were worse than those for bare-metal stent ISR. Multivariate analysis revealed that ESRD, and coronary ostial lesion, and the severity of pre-PCI stenosis were independently associated with target lesion restenosis following DEB use (P = 0.020, P = 0.009, P = 0.026, respectively).ESRD, and coronary ostial lesion, and the severity of pre-PCI stenosis were independently associated with recurrent target lesion restenosis following DEB use.

Who is responsible for the consequences? A case of stent thrombosis subsequent to noncompliance with post angioplasty treatment regimen

Coronary artery disease (CAD) is a major cause of mortality internationally and in Pakistan. Angioplasty has been proven to be an effective treatment for CAD. Stent thrombosis is a known but preventable complication of angioplasty. Several factors may lead to stent thrombosis with non-compliance with the prescribed drug regimen, being one of the most important factors. We report a case of stent thrombosis after four months of angioplasty. After exploring of patient's post angioplasty routines, it was found that the patient was non-compliant with the prescribed anti- platelets and other prescribed drugs. This time the patient presented with another acute myocardial infarction, and he went through angioplasty again.

Platelet reactivity and clinical outcomes after coronary artery implantation of drug-eluting stents (ADAPT-DES): a prospective multicentre registry study

BACKGROUND

The relation between platelet reactivity and stent thrombosis, major bleeding, and other adverse events after coronary artery implantation of drug-eluting stents has been incompletely characterised. We aimed to determine the relation between platelet reactivity during dual therapy with aspirin and clopidogrel and clinical outcomes after successful coronary drug-eluting stent implantation.

METHODS

ADAPT-DES was a prospective, multicentre registry of patients successfully treated with one or more drug-eluting stents and given aspirin and clopidogrel at 10-15 US and European hospitals. We assessed platelet reactivity in those patients after successful percutaneous coronary intervention using VerifyNow point-of-care assays, and assigned different cutoffs to define high platelet reactivity. The primary endpoint was definite or probable stent thrombosis; other endpoints were all-cause mortality, myocardial infarction, and clinically relevant bleeding. We did a propensity-adjusted multivariable analysis to determine the relation between platelet reactivity and subsequent adverse events. This study is registered with ClinicalTrials.gov, number NCT00638794.

FINDINGS

Between Jan 7, 2008, and Sept 16, 2010, 8665 patients were prospectively enrolled at 11 sites, of which 8583 were eligible. At 1-year follow-up, stent thrombosis had occurred in 70 (0·8%) patients, myocardial infarction in 269 (3·1%), clinically relevant bleeding in 531 (6·2%), and death in 161 (1·9%) patients. High platelet reactivity on clopidogrel was strongly related to stent thrombosis (adjusted HR 2·49 [95% CI 1·43-4·31], p=0·001) and myocardial infarction (adjusted HR 1·42 [1·09-1·86], p=0·01), was inversely related to bleeding (adjusted HR 0·73 [0·61-0·89], p=0·002), but was not related to mortality (adjusted HR 1·20 [0·85-1·70], p=0·30). High platelet reactivity on aspirin was not significantly associated with stent thrombosis (adjusted HR 1·46 [0·58-3·64], p=0·42), myocardial infarction, or death, but was inversely related to bleeding (adjusted HR 0·65 [0·43-0·99], p=0·04).

INTERPRETATION

The findings from this study emphasise the counter-balancing effects of haemorrhagic and ischaemic complications after stent implantation, and suggest that safer drugs or tailored strategies for the use of more potent agents must be developed if the benefits of greater platelet inhibition in patients with cardiovascular disease are to be realised.

FUNDING

Boston Scientific, Abbott Vascular, Medtronic, Cordis, Biosensors, The Medicines Company, Daiichi-Sankyo, Eli Lilly, Volcano, and Accumetrics.

Development and characterization of a coronary polylactic acid stent prototype generated by selective laser melting

In-stent restenosis is still an important issue and stent thrombosis is an unresolved risk after coronary intervention. Biodegradable stents would provide initial scaffolding of the stenosed segment and disappear subsequently. The additive manufacturing technology Selective Laser Melting (SLM) enables rapid, parallel, and raw material saving generation of complex 3- dimensional structures with extensive geometric freedom and is currently in use in orthopedic or dental applications. Here, SLM process parameters were adapted for poly-L-lactid acid (PLLA) and PLLA-co-poly-ε-caprolactone (PCL) powders to generate degradable coronary stent prototypes. Biocompatibility of both polymers was evidenced by assessment of cell morphology and of metabolic and adhesive activity at direct and indirect contact with human coronary artery smooth muscle cells, umbilical vein endothelial cells, and endothelial progenitor cells. γ-sterilization was demonstrated to guarantee safety of SLM-processed parts. From PLLA and PCL, stent prototypes were successfully generated and post-processing by spray- and dip-coating proved to thoroughly smoothen stent surfaces. In conclusion, for the first time, biodegradable polymers and the SLM technique were combined for the manufacturing of customized biodegradable coronary artery stent prototypes. SLM is advocated for the development of biodegradable coronary PLLA and PCL stents, potentially optimized for future bifurcation applications.

Vitamin C prevents hyperoxia-mediated coronary vasoconstriction and impairment of myocardial function in healthy subjects

Supplementary oxygen is commonly administered in current medical practice. Recently it has been suggested that hyperoxia causes acute oxidative stress and produces prompt and substantial changes in coronary resistance in patients with ischemic heart disease. In this report, we examined whether the effects of hyperoxia on coronary blood velocity (CBV) would be associated with a reduction in myocardial function. We were also interested in determining if the postulated changes in left ventricular (LV) function seen with tissue Doppler imaging (TDI) could be reversed with intravenous vitamin C, a potent, acute anti-oxidant. LV function was determined in eight healthy subjects with transthoracic echocardiography and TDI before and after hyperoxia and with and without infusing vitamin C. Hyperoxia compared with room air promptly reduced CBV by 28 ± 3% (from 23.50 ± 2.31 cm/s down to 17.00 ± 1.79 cm/s) and increased relative coronary resistance by 34 ± 5% (from 5.63 ± 0.88 up to 7.32 ± 0.94). Meanwhile, LV myocardial systolic velocity decreased by 11 ± 6% (TDI). These effects on flow and function were eliminated by the infusion of vitamin C, suggesting that these changes are mediated by vitamin C-quenchable substances acting on the coronary microcirculation.

[The bioresorbable coronary scaffold]

The routine placement of permanent metal stents has led to an improvement of the long-term and short-term effects of percutaneous coronary interventions. Treatment with the newest generation of drug-eluting stents results in a low risk of restenosis. The antiproliferative drug eluted by these stents, however, prevents endothelialisation; this leads to an increased risk of exposed metallic stent parts, which in turn leads to a higher risk of stent thrombosis. There is evidence that the vessel wall support provided by the stent is only a temporary requirement. Permanent metallic stents could, therefore, be superfluous in the long term. A bioresorbable vascular scaffold (BVS), manufactured from polylactic acid and completely resorbed within 18-24 months, is a new alternative. It is expected that these scaffolds will lead to the disappearance of the risk of late stent thrombosis. Theoretically, the bioresorbable vascular scaffold also provides a considerable advantage for patients who will probably have to undergo further coronary intervention in the future. Metal stents can be an important limiting factor for these patients.

Safety and efficacy of dalcetrapib on atherosclerotic disease using novel non-invasive multimodality imaging (dal-PLAQUE): a randomised clinical trial

BACKGROUND

Dalcetrapib modulates cholesteryl ester transfer protein (CETP) activity to raise high-density lipoprotein cholesterol (HDL-C). After the failure of torcetrapib it was unknown if HDL produced by interaction with CETP had pro-atherogenic or pro-inflammatory properties. dal-PLAQUE is the first multicentre study using novel non-invasive multimodality imaging to assess structural and inflammatory indices of atherosclerosis as primary endpoints.

METHODS

In this phase 2b, double-blind, multicentre trial, patients (aged 18-75 years) with, or with high risk of, coronary heart disease were randomly assigned (1:1) to dalcetrapib 600 mg/day or placebo for 24 months. Randomisation was done with a computer-generated randomisation code and was stratified by centre. Patients and investigators were masked to treatment. Coprimary endpoints were MRI-assessed indices (total vessel area, wall area, wall thickness, and normalised wall index [average carotid]) after 24 months and (18)F-fluorodeoxyglucose ((18)F-FDG) PET/CT assessment of arterial inflammation within an index vessel (right carotid, left carotid, or ascending thoracic aorta) after 6 months, with no-harm boundaries established before unblinding of the trial. Analysis was by intention to treat. This trial is registered at ClinicalTrials.gov, NCT00655473.

FINDINGS

189 patients were screened and 130 randomly assigned to placebo (66 patients) or dalcetrapib (64 patients). For the coprimary MRI and PET/CT endpoints, CIs were below the no-harm boundary or the adverse change was numerically lower in the dalcetrapib group than in the placebo group. MRI-derived change in total vessel area was reduced in patients given dalcetrapib compared with those given placebo after 24 months; absolute change from baseline relative to placebo was -4·01 mm(2) (90% CI -7·23 to -0·80; nominal p=0·04). The PET/CT measure of index vessel most-diseased-segment target-to-background ratio (TBR) was not different between groups, but carotid artery analysis showed a 7% reduction in most-diseased-segment TBR in the dalcetrapib group compared with the placebo group (-7·3 [90% CI -13·5 to -0·8]; nominal p=0·07). Dalcetrapib did not increase office blood pressure and the frequency of adverse events was similar between groups.

INTERPRETATION

Dalcetrapib showed no evidence of a pathological effect related to the arterial wall over 24 months. Moreover, this trial suggests possible beneficial vascular effects of dalcetrapib, including the reduction in total vessel enlargement over 24 months, but long-term safety and clinical outcomes efficacy of dalcetrapib need to be analysed.

FUNDING

F Hoffmann-La Roche Ltd.

Association between plasma pigment epithelium-derived factor levels and tissue characteristics of coronary plaque using integrated backscatter intravascular ultrasound

OBJECTIVE

Recent evidence has strongly suggested that atherosclerosis is an angiogenic disease, and PEDF may play a significant role in determining the balance of angiogenesis/antiangiogenesis during atherogenesis. Therefore, we assessed the associations among plasma levels of pigment epithelium-derived factor (PEDF), high-sensitivity C-reactive protein (hsCRP), the lipid profile and tissue characteristics of coronary plaque as assessed by integrated backscatter intravascular ultrasound (IB-IVUS).

METHODS

Fifty-two consecutive patients with stable coronary artery disease who underwent percutaneous coronary intervention were enrolled. Non-target coronary lesions with mild to moderate stenosis were measured by IB-IVUS. A total of 20 IB-IVUS images were recorded at an interval of 0.5 mm for a length of 10 mm in each plaque.

RESULTS

Although the percentage of plaque volume (%PV, 100×total PV/total vessel volume), percentage of lipid volume (%LV, 100×LV/PV) and percentage of fibrous volume (%FV, 100×FV/PV) were not associated with plasma log[PEDF] levels in the overall patients, in the patients without statin treatment %LV and %FV were correlated with plasma log[PEDF] levels (r=0.525, p=0.021 and r=-0.498, p=0.030, respectively).

CONCLUSION

The plasma level of PEDF may be a useful biomarker for predicting the tissue characteristics of coronary plaque using IB-IVUS.

Follow-up chest X-ray in patients with Kawasaki disease: the significance and clinical application of coronary artery macro-calcification

Kawasaki disease (KD) related coronary artery (CA) aneurysms may lead to significant and potentially insidious progressive stenosis. It is also well recognized that CA scarring leads to heavy calcification in KD. We intended to correlate the angiographic anomalies associated with coronary calcifications in KD and to evaluate the chronology and the detection rate of KD-related CA calcification on plain chest X-ray. Between 1992 and 2006, 65 CA angiograms were performed in 50 KD patients. Chest fluoroscopies and angiograms were retrospectively reviewed. When angiograms were abnormal, chest X-rays were reviewed by two radiologists blinded to the results of angiograms. CA lesions were identified in 18/50 (36%) patients, including isolated CA aneurysms in 10. All 8 patients who had CA aneurysms associated with stenosis and/or occlusion had CA calcification identifiable on chest X-ray. All significant stenotic lesions were concomitant with calcification. Plain chest X-ray, a simple inexpensive low dose mean, easily identifies KD patients at risk for serious CA stenosis when specific search for CA calcification is pursued. When detected, a closer tracking of coronary artery patency is warranted via other imaging techniques, usually expensive, invasive, requiring sedation in children or exposing to high radiation.

Drug-eluting balloon: very short-term exposure and overlapping

Paclitaxel balloon coating has shown promising effects in inhibiting restenosis in initial clinical trials. The aim of the present study was to evaluate the influence of two critical features of drug-eluting balloon (DEB) application - inflation time and increased dose due to overlapping balloons. Fifty-six stainless steel stents were implanted in the left anterior descending and circumflex coronary arteries of 28 domestic pigs using a 1.2:1.0 overstretch ratio. Stents were mounted on conventional uncoated and paclitaxel-coated angioplasty balloon catheters. The animals were randomized to five different treatments with a range of short (10 seconds [s] inflation using 1 DEB) to extended (2x60 s inflation using 2 DEB) intima contact time. After 28 days, quantitative angiography and histomorphometry of the stented arteries was performed on a total of 23 pigs. Paclitaxel balloon coating led to a marked reduction of parameters characterizing in-stent stenosis: Late lumen loss was 1.37 +/- 0.49 mm for uncoated balloons, 0.23 +/- 0.42 mm for one coated balloon 60 s inflation time, 0.37 +/- 0.28 mm for 10 s inflation time and 0.30 +/- 0.19 mm for the vessel segment treated by two coated balloons with 60 s inflation each. Neointimal areas were 4.26 +/- 1.18, 1.68 +/- 0.23, 1.83 +/- 0.40 and 1.67 +/- 0.46 mm(2), respectively (p = 0.001 versus control, p > 0.05 between paclitaxel-treated groups). Despite the marked reduction of neointimal proliferation, endothelialization of stent struts was present in all samples. DEB were found to effectively reduce neointimal proliferation regardless of inflation time and dose within the tested range. No adverse reactions were seen as dose was increased to more than three times the clinically tested dose.

[Design optimization of endovascular stent by finite element method]

Stent implantation is now the favorable therapy of coronary heart disease, but the restenosis occurring in association with the currently used stents device has become the main obstacle limiting the further development of stent. To change the expanding behavior of endovascular stents by way of design optimization is considered one of the effective approaches for reducing the damage to the intima of blood vessel and thereby decreasing the in-stent restenosis. So in this paper, the finite element method was used to systematically simulate and analyze the influences of different width of ring supporter and the non-symmetrical design of stent on its transitorily expanding behavior. The results show that among the structure parameters, the width of ring supporter of stent influences its expanded pressure remarkably. When designing the endovascular stent, we make its ring supporter unsymmetrical, i. e., we make the width of ring supporter of stent change degressively from its central part to end part. By this means, the dogboning, which normally happens in the expanding process of the balloon/stent system, can be effectively controlled and the acute vascular injuries can be reduced.

Olmesartan, But Not Amlodipine, Improves Endothelium-Dependent Coronary Dilation in Hypertensive Patients

OBJECTIVES

We aimed to compare the effects of the angiotensin II receptor blocker (ARB) olmesartan versus the calcium channel blocker (CCB) amlodipine on coronary endothelial dysfunction in patients with hypertension.

BACKGROUND

Angiotensin II receptor blockers are thought to have greater beneficial effects than CCBs on coronary vasomotion by directly blocking action of angiotensin II.

METHODS

Twenty-six patients with untreated essential hypertension were prospectively assigned to treatment with either olmesartan (27.7 +/- 12.4 mg/day, n = 13) or amlodipine (5.6 +/- 1.5 mg/day, n = 13) for 12 weeks. Changes of corrected myocardial blood flow (DeltaMBF) and coronary vascular resistance (DeltaCVR) from rest to cold pressor were measured by using 15O-water and positron emission tomography before and after treatment. Blood biomarkers including lipids, glucose, insulin, high-sensitivity C-reactive protein, interleukin-6, tumor necrosis factor-alpha, and superoxide dismutase (SOD) were also measured.

RESULTS

Olmesartan and amlodipine reduced blood pressure (BP) to the same extent (-28.7 +/- 16.2 mm Hg vs. -26.7 +/- 10.8 mm Hg). In the olmesartan group, DeltaMBF tended to be greater (-0.15 +/- 0.19 ml/g/min vs. 0.03 +/- 0.17 ml/g/min, p = 0.09 by 2-way analysis of variance), and DeltaCVR was significantly decreased (7.9 +/- 23.5 mm Hg/[ml/g/min] vs. -16.6 +/- 18.0 mm Hg/[ml/g/min], p < 0.05) after treatment, whereas these parameters did not change in the amlodipine group (DeltaMBF: -0.15 +/- 0.12 ml/g/min vs. -0.12 +/- 0.20 ml/g/min; DeltaCVR: 6.5 +/- 18.2 mm Hg/[ml/g/min] vs. 4.8 +/- 23.4 mm Hg/[ml/g/min]). Serum SOD activity tended to increase (4.74 +/- 4.77 U/ml vs. 5.57 +/- 4.74 U/ml, p = 0.07 by 2-way analysis of variance) only in the olmesartan group.

CONCLUSIONS

Olmesartan, but not amlodipine, improved endothelium-dependent coronary dilation in hypertensive patients independent of BP reduction. These beneficial effects on coronary vasomotion might be via an antioxidant property of ARBs.

A tale of two stents: perioperative management of patients with drug-eluting coronary stents

Drug-eluting stents were introduced into clinical practice to decrease coronary stent restenosis rates. Though remarkably effective in reducing this complication, recent data reveal that drug-eluting stents pose a significant risk for late stent thrombosis, an event strongly correlated with discontinuation of anti-platelet therapy. Because anti-platelet agents are often discontinued perioperatively, patients with DES are at risk for perioperative stent thrombosis and myocardial infarction. Along with a review of the recent literature, we present two cases of patients with drug-eluting stents scheduled for renal transplantation. Two distinct antithrombotic management strategies illustrate the risk of either approach-bleeding and transfusion versus stent thrombosis and myocardial infarction.

Effect of statin treatment on aortic valve and coronary artery calcification

BACKGROUND AND AIM OF THE STUDY

Conflicting data exist regarding statins and the progression of aortic valve disease. Hence, further information is required to determine if statin treatment has a beneficial effect on aortic valve calcification, and whether the inflammatory status of the patient affects aortic valve disease progression. The study aim was to evaluate the concomitant effect of statin treatment on aortic valve and coronary artery calcification and to compare results with the inflammatory status of the patient.

METHODS

Sixty-one patients with moderate to severe aortic stenosis (AS) were enrolled in this single-center, prospective observational study evaluating progression of aortic valve calcification. Patients underwent baseline and one-year echocardiography and electron-beam computed tomography. Blood samples were withdrawn at baseline and at one year for measurement of inflammatory biomarkers.

RESULTS

There was no significant reduction in calcium accumulation in the aortic valve of the statin group compared to the non-statin group, but there was trend towards less progression of calcification for the statin group. A significant inhibition of the coronary artery calcification volume score was observed for the statin group compared to the non-statin group. On echocardiography, statin treatment had no significant impact on aortic valve stenosis. Patients with serum LDL level >130 mg/dl showed less progression of coronary artery calcification when treated with statin drugs. The level of high-sensitivity C-reactive protein (hsCRP) significantly correlated with the progression of calcification for both the aortic valve and coronary arteries.

CONCLUSION

Whilst there was no significant benefit of statin treatment on aortic valve calcification over one year, there was a decreased progression of coronary artery calcification. The baseline level of hsCRP was predictive of progression of both aortic valve and coronary artery calcification, and may identify a high-risk population requiring aggressive control, either with statins or emerging drugs targeted at the inflammatory process of atherosclerosis.

Pharmacogenomics of Renin Angiotensin System Inhibitors in Coronary Artery Disease

Renin Angiotensin System (RAS) inhibitors comprise some of the most commonly used medications in coronary artery disease (CAD) and its related syndromes. Unfortunately, significant inter-patient variability seems likely in response to these agents; of which, the influence of genetic determinants is of interest. This review summarizes the available RAS inhibitor pharmacogenomic studies which have evaluated RAS polymorphisms that either elucidate mechanism via surrogate endpoint measurements, or predict efficacy via clinical outcomes in CAD related syndromes.Regardless of the endpoint, none of the RAS genotypes conclusively predicts efficacy of RAS inhibitors. In fact, the results of the pharmacogenomic studies were often in direct conflict with one another. Varied results appear due to methodological limitations (e.g., inadequate study power, genotyping error, methods of endpoint measurement), study conceptualization (e.g., overestimating the contribution of polymorphism to disease, lack of haplotype approach), and differences between studies (e.g., genotype frequency, study subject characteristics, the specific medication and dose used). Thus investigators should consider the various methodological limitations to improve upon the current approach to RAS inhibitor pharmacogenomic research in the vast CAD population.

Prolonged intravenous eptifibatide infusion for prevention of coronary stent thrombosis

Coronary bare-metal stent thrombosis usually occurs within a week of angioplasty, and may result in myocardial infarction and death. Thrombosis is effectively prevented by antiplatelet therapy with aspirin and clopidogrel. We describe a patient who was unable to ingest oral medication after angioplasty due to gastrointestinal surgery, and was therefore at risk for stent thrombosis. Intravenous eptifibatide was infused for 8 days in order to achieve parenteral platelet inhibition. We suggest a role for long-term intravenous administration of glycoprotein IIb/IIIa inhibitors for prevention of stent thrombosis in patients unable to take oral antiplatelet therapy.

[Long-term clinical efficiency of endovascular treatment using Cypher rapamycin-eluting stents in patients with coronary heart disease]

The study was undertaken to analyze the long-term results in patients with coronary heart disease (CHD) one year or more after Cypher stent implantation. It covered 1221 patients. One-, two-, and three- vessel lesions were observed in 693 (56.8%), 344 (28.2%), and 184 (15%) patients, respectively. A total of 1967 Cypher stents were implanted. The results of treatment were analyzed 1 and 2 years after intervention. The efficiency of a procedure was evaluated by the following parameters: the presence or absence of anginal symptoms, the presence and absence of complications (fatal outcome, myocardial infarction). The following morphological parameters: the rate of restenosis and that of late stent thrombosis were also assessed. The results of one- and two-year follow-ups were used to make a multivariate analysis of the clinical and morphological predictors of coronary complications (fatal outcome, myocardial infarction, recurrent angina pectoris) in the late period, as well as the predictors of restenosis and late stent thrombosis. Restenosis following 1 year of Cypher stent implantation is 3.1%. The factors that significantly increase the risk of this complication within the first year are diabetes mellitus and revascularization in the patients operated on. The one-year rate of Cypher stent thromboses is 1.6%. Patients' discontinuation of antiaggregant therapy is the sole factor that significantly increases the rate of their late thromboses in this period. Within the second year of a follow-up, the rate of late Cypher stent thromboses is 1.8%. The risk of this complication is significantly increased by factors, such as a lengthy (more than 3 mm) stented portion, renal failure, and less than 40% left ventricular ejection fraction.

The clinical trial of Women On the Move through Activity and Nutrition (WOMAN) study

The Women On the Move through Activity and Nutrition (WOMAN) study is the first randomized clinical trial of nonpharmacological intervention designed to modify lipoproteins, weight loss and exercise among postmenopausal women using noninvasive measures of atherosclerosis as the primary endpoint. The trial was initially designed to test whether intervention as compared to health education would be more effective in slowing progression of subclinical atherosclerosis among women on hormone therapy (HT), estrogen or estrogen+progestin. It was designed and implemented prior to the results of the Women's Health Initiative (WHI). The trial was since modified to include women who had been on HT but went off after the results of the WHI were reported. Eligible women were between the ages of 52-62, had waist circumference>or=80 cm, low density lipoprotein cholesterol between 100-160 mg% and controlled blood pressure. The intervention is low in total and saturated fat, trans fats, higher in fiber and promotes loss of 7-10% of body weight and includes at least 150 min of physical activity per week. The study has recruited 508 women. The primary endpoints are change in extent of carotid intima-media wall thickness as measured by carotid ultrasound, pulse wave velocity as a measure of vascular stiffness and coronary artery calcium using electron beam computed tomography. Body composition is measured by dual-energy X-ray absorptiometry.

P-wave duration and dispersion in patients with coronary slow flow and its relationship with Thrombolysis in Myocardial Infarction frame count

AIM

P-wave dispersion (PD), and duration has been reported to be associated with inhomogeneous and discontinuous propagation of sinus impulses. The aim of this study was to investigate the PD in patients with coronary slow flow (CSF) phenomenon.

METHODS

Study population included 48 patients with angiographically proven normal coronary arteries and slow coronary flow in all 3 coronary vessels (group I, 36 men; mean age, 54 +/- 9 years) and 32 subjects with angiographically proven normal coronary arteries without associated slow coronary flow (group II, 24 men, mean age, 53 +/- 10 years). Coronary flow rates of all patients and control subjects were documented by Thrombolysis In Myocardial Infarction (TIMI) frame count. All patients in group I had TIMI frame counts greater than 2 SD above those of control subjects (group II). The mean TIMI frame count for each patient and control subject was calculated by adding the TIMI frame counts for each major epicardial coronary artery and then dividing the obtained value into 3. The maximum and minimum P-wave duration (P(max) and P(min)) and PD were measured from the 12-lead surface electrocardiogram. Echocardiographic examination was also performed.

RESULTS

There was no statistically significant difference between the 2 groups with respect to age, sex, hypertension, diabetes mellitus, hyperlipidemia, and cigarette smoking (P > .05). P-wave dispersion and P(max) of patients with CSF were found to be significantly higher than those of control subjects (39.4 +/- 17 vs 21.2 +/- 10 milliseconds and 121.6 +/- 17.1 vs 104.3 +/- 10.4 milliseconds, respectively; P < .0001). Moreover, we found a significant positive correlation between both P(max) and PD with mean TIMI frame count (r = 0.836 and r = 0.806, respectively; P < .0001).

CONCLUSIONS

P-wave dispersion and P-wave duration both were found to be greater in patients with CSF than in controls.

Duale antiaggregatorische Therapie nach Implantation von Koronarstents

Dual antiplatelet-aggregation treatment with aspirin and clopidogrel after coronary stent implantation is nowadays standard peri-interventional practice, although its use is not yet licensed for this indication in many European countries. Clopidogrel administration is initiated before PCI with a loading dose of 300 mg when given at least 6 hours before PCI, otherwise 600 mg. The required duration of combined (aspirin + clopidogrel) antiplatelet-aggregation treatment after coronary stent implantation depends on the type of stent and the pre-existing disease. After bare-metal stent implantation dual antiplatelet medication is needed for at least 3-4 weeks, after drug-eluting stent implantation 6 months, after coronary brachytherapy 12 months, and 9 months after an acute coronary syndrome. These time intervals should also be respected before any elective surgical intervention. Early operations, because postponement is impossible, should be performed under antiplatelet-aggregation treatment after assessment of bleeding risk in the individual case. Premature termination of this treatment carries an increased risk of serious cardiovascular events, especially stent thrombosis and myocardial infarction. Prolonged antiplatelet-aggregation treatment is of benefit especially in patients with a high risk of serious cardiovascular events. Patients with an indication for long-term anticoagulation may require, during the period of highest risk of stent thrombosis after stent implantation, administration of combined aspirin, clopidogrel and anticoagulants with an INR target value in the lower therapeutic range. The increased risk of bleeding must be weighed up against the potential benefit.

Five-year results of a randomized, single-center study of tacrolimus vs microemulsion cyclosporine in heart transplant patients

BACKGROUND

Previous multicenter, randomized trials, lacking standardized post-transplant protocols, have compared tacrolimus (Tac) and cyclosporine (CyA, Sandimmune) and demonstrated similar outcomes with some different adverse effects. The microemulsion form of CyA (mCyA, Neoral) has replaced Sandimmune CyA as the more widely utilized CyA formulation. This is the first 5-year follow-up study of a large, single-center trial (n = 67) under a standardized post-transplant protocol comparing Tac and mCyA.

METHODS

Sixty-seven heart transplant patients were randomized to Tac (n = 33) or mCyA (n = 34), both in combination with corticosteroids and azathioprine without cytolytic induction. Five-year end-points included survival, Grade > or = 3A or treated rejection, angiographic cardiac allograft vasculopathy (CAV; any lesion > or = 30% stenosis), renal dysfunction (creatinine > or = 2.0 mg/dl), use of two or more anti-hypertensive medications, percent diabetic and lipid levels.

RESULTS

Five-year survival, freedom from Grade > or = 3A or any treated rejection and angiographic CAV, mean cholesterol level and percent diabetic were similar between the two groups. The Tac group had a significantly lower 5-year mean triglyceride level (Tac 97 +/- 34 vs mCyA 175 +/- 103 mg/dl, p = 0.011) and average serum creatinine level (Tac 1.2 +/- 0.5 mg/dl vs mCyA 1.5 +/- 0.4 mg/dl, p = 0.044). There was a trend toward fewer patients requiring two or more anti-hypertensive drugs in the Tac group (Tac 33% vs mCyA 59%, p = 0.065).

CONCLUSIONS

Tac and mCyA appear to be comparable with regard to 5-year survival, freedom from rejection and CAV. However, compared with mCyA, Tac appears to reduce the adverse effect profile for hypertriglyceridemia and renal dysfunction and the need for hypertensive medications.

Finite element analysis and stent design: Reduction of dogboning

In Western countries, cardiovascular disease is the most common cause of death, often related to atherosclerosis. This paper offers a brief introduction into some aspects of this disease and its treatment, where the use of stents is gaining increasing importance. Stents are supporting - mostly metal - tubular mesh structures which are opened in an obstructed artery in order to reopen it, and to offer radial strength to prevent elastic recoil of the dilated vessel. In addition to a variety of experimental tests to study the behavior of (new) stent designs, advanced numerical models (e.g. Finite Element Models) may offer interesting insights in the mechanical behavior of stents and will undoubtedly influence the design of future generation stents. A brief literature review on numerical studies dealing with the mechanical behavior of stents is presented. Subsequently, the finite element method is exploited to investigate and compare different designs of a "first generation" Palmaz Schatz stent in order to reduce the dogboning (i.e. ends of stent open first during expansion) to a minimum. Our computational models (Abaqus ) are described in terms of geometry, constitutive material models, numerical aspects and output quantities. Altering the original symmetric stent design to asymmetric designs decreased the dogboning from 27.24% to less than 10% for the vast majority of the studied asymmetric designs. For one particular configuration, the dogboning effect vanished completely. For this reason, taking asymmetry into account in the design of stents seems very promising, at least from the perspective of dogboning. However, as the dogboning only takes into account the radii (R) at the central and distal part of the stent, nothing can be concluded concerning the uniformity of the complete stent expansion. The mean value (Rm) and the root mean square (R(RMS)) of radii (differences) of the stent at the end of the loading phase (P = 0.7 N/mm2) are much better parameters to give a clear indication of the uniformity of the expanded stent's shape. Although the model is suitable to study basic aspects of stent deployment, further research is necessary, especially accounting for newer generation stent geometries and more realistic balloon-stent interaction.

Meta-analysis of MTHFR 677C->T polymorphism and coronary heart disease: does totality of evidence support causal role for homocysteine and preventive potential of folate?

OBJECTIVES

To investigate the association between the MTHFR 677C-->T polymorphism and coronary heart disease, assessing small study bias and heterogeneity between studies.

DATA SOURCES

Medline and Embase citation searches between January 2001 and August 2004; no language restrictions.

STUDY SELECTION

Case-control and prospective studies of association between MTHFR 677C-->T variant and myocardial infarction, coronary artery occlusion, or both; 80 studies were included.

DATA EXTRACTION

Data on genotype frequency and mean homocysteine concentrations by genotype were extracted. Odds ratios were calculated for TT genotype versus CC genotype. Heterogeneity was explored, with stratification by geographical region of the study samples, and meta-regression by difference in mean serum homocysteine concentrations (CC minus TT genotypes) was carried out.

RESULTS

26,000 cases and 31,183 controls were included. An overall random effects odds ratio of 1.14 (95% confidence intervals 1.05 to 1.24) was found for TT versus CC genotype. There was strong evidence of heterogeneity (P < 0.001, I2 = 38.4%), which largely disappeared after stratification by geographical region. Odds ratios in Europe, Australia, and North America attenuated towards the null, unlike those in the Middle East and Asia.

CONCLUSIONS

No strong evidence exists to support an association of the MTHFR 677 C-->T polymorphism and coronary heart disease in Europe, North America, or Australia. Geographical variability may be due to higher folate intake in North America and Europe or to publication bias. The conclusion drawn from previous meta-analyses that folic acid, through lowering homocysteine, has a role in prevention of cardiovascular disease is in some doubt.

Non-invasive evaluation of coronary calcium

With the increasing diffusion of 4-row,16-row and 64-row multislice computed tomography scanners, widespread coronary calcium scoring has become possible in Europe. This relatively easy-to-perform test has a high sensitivity and low specificity for the detection of significant coronary artery stenosis, and may have an important role in the risk stratification for future coronary artery events in selected groups of patients, such as those immediately at risk. This study reviews the techniques available for coronary calcium scoring (electron beam tomography and multislice computed tomography) with their respective protocols, as well as their advantages and disadvantages. The methods for interpreting the results, the potential indications and the clinical applications of the techniques are also described.

Exercise training increases basal tone in arterioles distal to chronic coronary occlusion

Endurance exercise training increases basal active tone in coronary arteries and enhances myogenic tone in coronary arterioles of control animals. Paradoxically, exercise training has also been shown to augment nitric oxide production and nitric oxide-mediated relaxation in coronary arterioles. The purpose of the present study was to examine the effect of exercise training on basal active tone of arterioles (approximately 150 microm ID) isolated from the collateral-dependent region of hearts exposed to chronic coronary occlusion. Ameroid occluders were surgically placed around the proximal left circumflex coronary artery of miniature swine. Arterioles were isolated from both the collateral-dependent and nonoccluded myocardial regions of sedentary (pen confined) and exercise-trained (treadmill run; 14 wk) pigs. Coronary tone was studied in isolated arterioles using microvessel myographs and standard isometric techniques. Exposure to nominally Ca2+-free external solution reduced resting tension in all arterioles; decreases were most profound (P < 0.05) in arterioles from the collateral-dependent region of exercise-trained animals. Furthermore, nitric oxide synthase (NOS) inhibition (N(omega)-nitro-L-arginine methyl ester; 100 microM) unmasked markedly increased nitric oxide-sensitive tone in arterioles from the collateral-dependent region of exercise-trained swine. Blockade of K+ channels revealed significantly enhanced K+ channel contribution to basal tone in collateral-dependent arterioles of exercise-trained pigs. Protein content of endothelial NOS (eNOS) and phosphorylated eNOS (pS1179), determined by immunoblot, was elevated in arterioles from exercise-trained animals with the greatest effect in collateral-dependent vasculature. Taken together, we demonstrate the interaction of opposing exercise training-enhanced arteriolar basal active tone, nitric oxide production, and K+ channel activity in chronic coronary occlusion, potentially enhancing the capacity to regulate blood flow to collateral-dependent myocardium.

Peroxisome proliferator-activated receptor gamma; Its role in atherosclerosis and restenosis

Cellular proliferation and migration are fundamental processes that contribute to the injury response in major blood vessels. The resultant pathologies are atherosclerosis and restenosis. As we begin to understand the cellular changes associated with vascular injury, it is critical to determine whether the inhibition of growth and movement of cells in the vasculature could serve as a novel therapeutic strategy to prevent atherosclerosis and restenosis.

Long-Term Changes in Coronary Artery Aneurysms in Patients With Kawasaki Disease-Comparison of Therapeutic Regimens-

BACKGROUND

There are few studies of the therapeutic regimens for the prevention of stenotic transformation of aneurysms in Kawasaki disease (KD). The aim of this study was to assess the prophylactic effect of combined therapy in the acute stage and convalescent- to chronic-stage against the formation of stenotic lesions.

METHODS AND RESULTS

In 85 patients, 103 giant aneurysms (ANl), 46 medium-sized aneurysms (ANm), and 13 small aneurysms (ANs) were analyzed. With respect to therapy in the acute stage, no localized stenosis of ANl in the left coronary artery was noted in patients who received high-dose gamma globulin therapy (G). For ANm, the group (G) showed a significantly higher regression rate than the aspirin group and steroids group. Furthermore, no coronary artery occlusion/recanalization of ANl occurred with the prophylactic regimen of aspirin and warfarin {aw}. Prophylaxis {aw} and the prophylactic regimen of aspirin alone {a} significantly lowered the incidence compared with either the prophylactic regimen of warfarin {w} or no prophylaxis {n}. However, no significant differences were noted between prophylaxis {w} and {n}.

CONCLUSIONS

High-dose gamma globulin therapy in the acute stage of KD is the first choice for the prevention of stenotic transformation. Prophylaxis {aw} is recommended for ANl.