Effects of complete revascularization according to age in patients with ST-segment elevation myocardial infarction and multivessel disease (COMPLETE-AGE)

BACKGROUND

In ST-segment elevation myocardial infarction (STEMI), complete revascularization with percutaneous coronary intervention (PCI) reduces major cardiovascular events compared with culprit-lesion-only PCI. Whether age influences these results remains unknown.

METHODS

COMPLETE was a multinational, randomized trial evaluating a strategy of staged complete revascularization, consisting of angiography-guided PCI of all suitable nonculprit lesions, versus a strategy of culprit-lesion-only PCI. In this prespecified subgroup analysis, treatment effect according to age (≥65 years vs <65 years) was determined for the first coprimary outcome of cardiovascular (CV) death or new myocardial infarction (MI) and the second coprimary outcome of CV death, new MI, or ischemia-driven revascularization (IDR). Median follow-up was 35.8 months (interquartile range [IQR]: 27.6-44.3 months).

RESULTS

Of 4,041 patients randomized in COMPLETE, 1,613 were aged ≥ 65 years (39.9%). Higher event rates were observed for both coprimary outcomes in patients aged ≥ 65 years comparted with those aged < 65 years (11.2% vs 7.9%, HR 1.49, 95% CI 1.22-1.83; 14.4% vs 11.8%, HR 1.28, 95% CI 1.07-1.52, respectively). Complete revascularization reduced the first coprimary outcome in patients ≥ 65 years (9.7% vs 12.5%, HR 0.77; 95% CI, 0.58-1.04) and < 65 years (6.7% vs 9.1%, HR 0.72; 95% CI, 0.54-0.96)(interaction P = .74). The second coprimary outcome was reduced in those ≥ 65 years (HR 0.56, 95% CI, 0.43-0.74) and < 65 years (HR 0.48, 95% CI, 0.37-0.61 (interaction P = .37). A sensitivity analysis was performed with consistent results demonstrated using a 75-year threshold (albeit attenuated).

CONCLUSIONS

In patients with STEMI and multivessel CAD, complete revascularization compared with culprit-lesion-only PCI reduced major cardiovascular events regardless of patient age and could be considered as a revascularization strategy in older adults.

Fractional Flow Reserve-Guided PCI or Coronary Bypass Surgery for 3-Vessel Coronary Artery Disease: 3-Year Follow-Up of the FAME 3 Trial

BACKGROUND

Previous studies comparing percutaneous coronary intervention (PCI) with coronary artery bypass grafting (CABG) in patients with multivessel coronary disease not involving the left main have shown significantly lower rates of death, myocardial infarction (MI), or stroke after CABG. These studies did not routinely use current-generation drug-eluting stents or fractional flow reserve (FFR) to guide PCI.

METHODS

FAME 3 (Fractional Flow Reserve versus Angiography for Multivessel Evaluation) is an investigator-initiated, multicenter, international, randomized trial involving patients with 3-vessel coronary artery disease (not involving the left main coronary artery) in 48 centers worldwide. Patients were randomly assigned to receive FFR-guided PCI using zotarolimus drug-eluting stents or CABG. The prespecified key secondary end point of the trial reported here is the 3-year incidence of the composite of death, MI, or stroke.

RESULTS

A total of 1500 patients were randomized to FFR-guided PCI or CABG. Follow-up was achieved in >96% of patients in both groups. There was no difference in the incidence of the composite of death, MI, or stroke after FFR-guided PCI compared with CABG (12.0% versus 9.2%; hazard ratio [HR], 1.3 [95% CI, 0.98-1.83]; P=0.07). The rates of death (4.1% versus 3.9%; HR, 1.0 [95% CI, 0.6-1.7]; P=0.88) and stroke (1.6% versus 2.0%; HR, 0.8 [95% CI, 0.4-1.7]; P=0.56) were not different. MI occurred more frequently after PCI (7.0% versus 4.2%; HR, 1.7 [95% CI, 1.1-2.7]; P=0.02).

CONCLUSIONS

At 3-year follow-up, there was no difference in the incidence of the composite of death, MI, or stroke after FFR-guided PCI with current-generation drug-eluting stents compared with CABG. There was a higher incidence of MI after PCI compared with CABG, with no difference in death or stroke. These results provide contemporary data to allow improved shared decision-making between physicians and patients with 3-vessel coronary artery disease.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT02100722.

Joint British Societies' guideline on management of cardiac arrest in the cardiac catheter laboratory

More than 300 000 procedures are performed in cardiac catheter laboratories in the UK each year. The variety and complexity of percutaneous cardiovascular procedures have both increased substantially since the early days of invasive cardiology, when it was largely focused on elective coronary angiography and single chamber (right ventricular) permanent pacemaker implantation. Modern-day invasive cardiology encompasses primary percutaneous coronary intervention, cardiac resynchronisation therapy, complex arrhythmia ablation and structural heart interventions. These procedures all carry the risk of cardiac arrest.We have developed evidence-based guidelines for the management of cardiac arrest in adult patients in the catheter laboratory. The guidelines include recommendations which were developed by collaboration between nine professional and patient societies that are involved in promoting high-quality care for patients with cardiovascular conditions. We present a set of protocols which use the skills of the whole catheter laboratory team and which are aimed at achieving the best possible outcomes for patients who suffer a cardiac arrest in this setting. We identified six roles and developed a treatment algorithm which should be adopted during cardiac arrest in the catheter laboratory. We recommend that all catheter laboratory staff undergo regular training for these emergency situations which they will inevitably face.

Fractional Flow Reserve-Guided PCI as Compared with Coronary Bypass Surgery

BACKGROUND

Patients with three-vessel coronary artery disease have been found to have better outcomes with coronary-artery bypass grafting (CABG) than with percutaneous coronary intervention (PCI), but studies in which PCI is guided by measurement of fractional flow reserve (FFR) have been lacking.

METHODS

In this multicenter, international, noninferiority trial, patients with three-vessel coronary artery disease were randomly assigned to undergo CABG or FFR-guided PCI with current-generation zotarolimus-eluting stents. The primary end point was the occurrence within 1 year of a major adverse cardiac or cerebrovascular event, defined as death from any cause, myocardial infarction, stroke, or repeat revascularization. Noninferiority of FFR-guided PCI to CABG was prespecified as an upper boundary of less than 1.65 for the 95% confidence interval of the hazard ratio. Secondary end points included a composite of death, myocardial infarction, or stroke; safety was also assessed.

RESULTS

A total of 1500 patients underwent randomization at 48 centers. Patients assigned to undergo PCI received a mean (±SD) of 3.7±1.9 stents, and those assigned to undergo CABG received 3.4±1.0 distal anastomoses. The 1-year incidence of the composite primary end point was 10.6% among patients randomly assigned to undergo FFR-guided PCI and 6.9% among those assigned to undergo CABG (hazard ratio, 1.5; 95% confidence interval [CI], 1.1 to 2.2), findings that were not consistent with noninferiority of FFR-guided PCI (P = 0.35 for noninferiority). The incidence of death, myocardial infarction, or stroke was 7.3% in the FFR-guided PCI group and 5.2% in the CABG group (hazard ratio, 1.4; 95% CI, 0.9 to 2.1). The incidences of major bleeding, arrhythmia, and acute kidney injury were higher in the CABG group than in the FFR-guided PCI group.

CONCLUSIONS

In patients with three-vessel coronary artery disease, FFR-guided PCI was not found to be noninferior to CABG with respect to the incidence of a composite of death, myocardial infarction, stroke, or repeat revascularization at 1 year. (Funded by Medtronic and Abbott Vascular; FAME 3 ClinicalTrials.gov number, NCT02100722.).

Timing of Staged Nonculprit Artery Revascularization in Patients With ST-Segment Elevation Myocardial Infarction: COMPLETE Trial

BACKGROUND

The COMPLETE (Complete vs Culprit-only Revascularization to Treat Multi-vessel Disease After Early PCI for STEMI) trial demonstrated that staged nonculprit lesion percutaneous coronary intervention (PCI) reduced major cardiovascular (CV) events in patients with ST-segment elevation myocardial infarction (STEMI) and multivessel coronary artery disease (CAD).

OBJECTIVES

The purpose of this study was to determine the effect of nonculprit-lesion PCI timing on major CV outcomes and also the time course of the benefit of complete revascularization.

METHODS

Following culprit-lesion PCI, 4,041 patients with STEMI and multivessel CAD were randomized to staged nonculprit-lesion PCI or culprit-lesion only PCI. Randomization was stratified according to investigator-planned timing of nonculprit-lesion PCI: during or after the index hospitalization. The first coprimary outcome was the composite of CV death or myocardial infarction (MI). In pre-specified analyses, hazard ratios (HRs) were calculated for each time stratum. Landmark analyses of the entire population were performed within 45 days and after 45 days.

RESULTS

For nonculprit-lesion PCI planned during the index hospitalization (actual time: median 1 day), CV death or MI was reduced with complete revascularization compared with culprit-lesion only PCI (HR: 0.77; 95% confidence interval [CI]: 0.59 to 1.00). For nonculprit lesion PCI planned to occur after hospital discharge (actual time: median 23 days), CV death or MI was also reduced with complete revascularization (HR: 0.69; 95% CI: 0.49 to 0.97; interaction p = 0.62). Landmark analyses demonstrated an HR of 0.86 (95% CI: 0.59 to 1.24) during the first 45 days and 0.69 (95% CI: 0.54 to 0.89) from 45 days to the end of follow-up for intended nonculprit lesion PCI versus culprit lesion only PCI.

CONCLUSIONS

Among STEMI patients with multivessel disease, the benefit of complete revascularization over culprit-lesion only PCI was consistent irrespective of the investigator-determined timing of nonculprit-lesion intervention. The benefit of complete revascularization on hard clinical outcomes emerged mainly over the long term.

Flow cytometric analysis of circulating platelet-monocyte aggregates in whole blood: Methodological considerations

Platelet-monocyte aggregates are increasingly being used to quantify platelet activation.The variables that influence plateletmonocyte aggregates have not been well defined.We sought to determine the effect of blood collection, handling and processing techniques on detected levels of platelet-monocyte aggregates using a flow cytometric assay. Whole blood was labelled with anti-CD14-PE and anti-CD42a-FITC. Thereafter, samples were fixed and red cells lysed.Analysis was performed with the flow cytometer initially triggering on light scatter and then on FL-2 to identify CD14-PE positive monocytes. Platelet-monocyte aggregates were defined as monocytes positive for CD42a. The effect of collection, handling and processing techniques on this assay were assessed. Anticoagulation with heparin (20.1 ± 2.0%), PPACK (16.8 ± 1.9%), sodium citrate (12.3 ± 1.6%) and EDTA (9.5 ± 1.0%) resulted in markedly different levels of pla- gregation was higher in samples obtained from intravenous cannulae compared to those obtained by venepuncture (20.9 ± 3.9% vs.13.8 ± 2.4%,P=0.03).For every 10 minutes of delay prior to processing platelet-monocyte aggregates increased by 2.8% (P=0.0001) in PPACK anticoagulated blood and 1.7% (P=0.01) in citrate anticoagulated blood. Erythrocyte lysis together with fixation does not affect platelet-monocyte aggregation. Plateletmonocyte aggregates remained stable over 24 hours when fixed and stored at 4°C. Multiple handling and processing factors may affect platelet-monocyte aggregation. We recommend the measurement of platelet-monocyte aggregates on samples collected by direct venepuncture, using a direct thrombin inhibitor as the anticoagulant and minimising the time delay before sample fixation.

Secondary syphilis presenting with aortitis and coronary ostial occlusion

Aortitis is an established manifestation of tertiary syphilis. We report a rare case of aortitis with ostial occlusion and left ventricular failure in secondary syphilis. Her management required a true multidisciplinary approach from multiple specialities due to complications of concomitant psychosis and a history of anaphylaxis to penicillin. This case illustrates the complexities of diagnosing and managing a rare presentation of this increasingly prevalent infection.

Multiparametric cardiovascular magnetic resonance assessment of cardiac allograft vasculopathy

OBJECTIVES

This study sought to evaluate the diagnostic performance of multiparametric cardiovascular magnetic resonance (CMR) for detecting cardiac allograft vasculopathy (CAV) using contemporary invasive epicardial artery and microvascular assessment techniques as reference standards, and to compare the performance of CMR with that of angiography.

BACKGROUND

CAV continues to limit the long-term survival of heart transplant recipients. Coronary angiography has a Class I recommendation for CAV surveillance and annual or biannual surveillance angiography is performed routinely in most centers.

METHODS

All transplant recipients referred for surveillance angiography at a single UK center over a 2-year period were prospectively screened for study eligibility. Patients prospectively underwent coronary angiography followed by coronary intravascular ultrasound, fractional flow reserve, and index of microcirculatory resistance. Within 1 month, patients underwent multiparametric CMR, including assessment of regional and global ventricular function, absolute myocardial blood flow quantification, and myocardial tissue characterization. In addition, 10 healthy volunteers underwent CMR.

RESULTS

Forty-eight patients were recruited, median 7.1 years (interquartile range: 4.6 to 10.3 years) since transplantation. The CMR myocardial perfusion reserve was the only independent predictor of both epicardial (β = -0.57, p < 0.001) and microvascular disease (β = -0.60, p < 0.001) on stepwise multivariable regression. The CMR myocardial perfusion reserve significantly outperformed angiography for detecting moderate CAV (area under the curve, 0.89 [95% confidence interval (CI): 0.79 to 1.00] vs. 0.59 [95% CI: 0.42 to 0.77], p = 0.01) and severe CAV (area under the curve, 0.88 [95% CI: 0.78 to 0.98] vs. 0.67 [95% CI: 0.52 to 0.82], p = 0.05).

CONCLUSIONS

CAV, including epicardial and microvascular components, can be detected more accurately using noninvasive CMR-based absolute myocardial blood flow assessment than with invasive coronary angiography, the current clinical surveillance technique.

Effect of ω-3 fatty acid supplementation on endothelial function, endogenous fibrinolysis and platelet activation in patients with a previous myocardial infarction: a randomised controlled trial

OBJECTIVE

The mechanisms through which ω-3 fatty acids reduce adverse cardiac events remain uncertain. We aimed to investigate the effect of ω-3 fatty acid supplementation on endothelial vasomotor function, endogenous fibrinolysis, and platelet and monocyte activation in patients with coronary heart disease.

DESIGN

Randomised, double-blind, placebo-controlled, cross-over trial.

SETTING

Academic cardiac centre.

PARTICIPANTS

20 male patients with a previous myocardial infarction.

INTERVENTION

ω-3 Fatty acid supplementation (2 g/day for 6 weeks) versus olive oil placebo.

OUTCOME MEASURES

Peripheral blood was taken for analysis of platelet and monocyte activation, and forearm blood flow (FBF) was assessed in a subset of 12 patients during intrabrachial infusions of acetylcholine, substance P and sodium nitroprusside. Stimulated plasma tissue plasminogen activator (t-PA) concentrations were measured during substance P infusion.

RESULTS

All vasodilators caused dose-dependent increases in FBF (p<0.0001). ω-3 Fatty acid supplementation did not affect endothelium-dependent vasodilation with acetylcholine and substance P compared with placebo (p=0.5 and 0.9). Substance P caused a dose-dependent increase in plasma t-PA concentrations (p<0.0001), which was not affected by ω-3 fatty acid supplementation (p=0.9). ω-3 Fatty acids did not affect platelet-monocyte aggregation, platelet P-selectin or CD40L, or monocyte CD40.

CONCLUSIONS

We have demonstrated that dietary supplementation with ω-3 fatty acids does not affect endothelial vasomotor function, endothelial t-PA release, or platelet and monocyte activation in patients with coronary heart disease. Cardiac benefits conferred by ω-3 fatty acids in coronary heart disease are unlikely to be mediated through effects on these systems.

Effect of ω-3 fatty acid supplementation on endothelial function, endogenous fibrinolysis and platelet activation in male cigarette smokers

OBJECTIVE

The effects of ω-3 fatty acids on endothelial function, fibrinolysis and platelet function are uncertain. We investigated the effects of ω-3 fatty acid supplementation on endothelial vasomotor function, endogenous fibrinolysis, and platelet and monocyte activation in healthy cigarette smokers; a group at increased risk of myocardial infarction.

DESIGN, SETTING, PARTICIPANTS

Twenty cigarette smokers were recruited into a randomised, double-blind, placebo-controlled, crossover trial of ω-3 fatty acid supplementation.

INTERVENTION

ω-3 fatty acid supplements (2 g/day) or placebo for a 6-week period.

MAIN OUTCOME MEASURES

Peripheral blood was taken for analysis of platelet and monocyte activation, and forearm blood flow (FBF) was assessed in a subset of 12 smokers during intrabrachial infusions of acetylcholine, substance P and sodium nitroprusside. Stimulated plasma tissue plasminogen activator (t-PA) concentrations were measured during substance P infusion.

RESULTS

All vasodilators caused dose-dependent increases in FBF (p<0.0001). Compared with placebo, ω-3 fatty acid supplementation led to greater endothelium-dependent vasodilatation with acetylcholine and substance P (p=0.0032 and p=0.056). Substance P caused a dose-dependent increase in plasma t-PA concentrations (p<0.0001) that was greater after ω-3 fatty acid supplementation compared with placebo (8.8±2.3 IU ml(-1) vs 3.6±1.1 IU ml(-1); p=0.029). ω-3 fatty acids did not affect platelet-monocyte aggregation, platelet P-selectin or CD40L, or monocyte CD40.

CONCLUSIONS

We have demonstrated for the first time that ω-3 fatty acids augment acute endothelial t-PA release and improve endothelial vasomotor function in cigarette smokers. Improved endogenous fibrinolysis and endothelial function may represent important mechanisms through which ω-3 fatty acids confer potential cardiovascular benefits.

Study of Anomalies Associated With Labiopalatine Clefting

Background and aims: Cleft lip with or without cleft palate are the most common congenital malformations of the head and neck accounting for about 65% of all anomalies of this region. Approximately 70% of cleft cases are non-syndromic and occur as isolated condition, while remaining 30% cases are associated with systemic defects involving cardiovascular, musculoskeletal, genitourinary system and other structural anomalies. The purpose of this study is to assess the various anomalies associated with labiopalatine clefting. Materials and methods: Sixty four cases of cleft lip with or without cleft palate attending the OPD of Department of Plastic Surgery and Pediatric Surgery, Gauhati Medical College and Hospital, were studied. Among them three cases were found to be associated with other anomalies. Results: One case of cleft lip and palate presented with multiple anomalies like tongue tie, malformed external ear and micrognathia. Another one had acyanotic heart disease associated with cleft lip. A case of cleft lip and palate was also found to be associated with hydrocephalus. Conclusion : Proper knowledge and details of anomalies associated with orofacial cleft will help to provide necessary treatment and improve survival of these children.

Decompensated heart failure secondary to hypocalcaemia post coronary artery bypass grafting

A man presented with an exacerbation of heart failure following coronary artery bypass grafting. He was found to be severely hypocalcaemic secondary to a combination of decreased parathyroid reserve and severe vitamin D deficiency. On treatment of his hypocalcaemia, all symptoms resolved. This case highlights the importance of recognising that metabolic derangement can affect cardiac function.

A three-dimensional pharmacophore modelling of ITK inhibitors and virtual screening for novel inhibitors

Interleukin-2-inducible T-cell kinase (ITK) is a key member of the Tec family of non-receptor tyrosine kinases, and has been found to be a novel target for a number of inflammatory and autoimmune diseases. A three-dimensional pharmacophore model has been generated for protein ITK from its known inhibitors. The best HypoGen model consisted of four pharmacophore features: one hydrogen bond acceptor, one hydrogen bond donor and two hydrophobic rings. This model showed a correlation coefficient of 0.947, a root mean square deviation of 0.914 and a configuration cost of 16.866. The model was validated using test set prediction and Fischer's test. A test set containing 204 compounds showed an r(2) of 0.745 between estimated activity and activity measured experimentally. Fisher's test gave a confidence level of 95%. The best pharmacophore model (Hypo1) was then employed for virtual screening (3D database searching), including Lipinsiki's filter, to obtain a pool of more drug-like molecules. The molecular pool thus retrieved was subjected to docking analysis with a study protein to remove any molecules showing false positive activity for ITK.

Effect of moderate walnut consumption on lipid profile, arterial stiffness and platelet activation in humans

Background/Objectives

A large intake of walnuts may improve lipid profile and endothelial function. The effect of moderate walnut consumption is not known. We investigated whether a moderate intake of walnuts would affect lipid profile, arterial stiffness and platelet activation in healthy volunteers.

Subjects/Methods

Thirty healthy males were recruited into a single-blind randomised controlled crossover trial of 4 weeks dietary walnut supplementation (15 g/day) and 4 weeks control (no walnuts). Arterial stiffness was assessed using pulse waveform analysis to determine the augmentation index and augmented pressure. Platelet activation was determined using flow cytometry to measure circulating platelet-monocyte aggregates.

Results

There were no differences in lipid profile after 4 weeks of walnut supplementation compared with control. Dietary intake of alpha-linolenic acid was increased during the walnut diet (2.1±0.4 g/day versus 0.7±0.4 g/day, P<0.0001). There were no differences in augmentation index or augmented pressure during walnut supplementation. Walnut supplementation did not affect platelet-monocyte aggregation .

Conclusions

Dietary intervention with a moderate intake of walnuts does not affect lipid profile, arterial stiffness or platelet activation in man. Our results suggest that the potentially beneficial cardiac effects of walnuts may not be apparent at lower and more practical levels of consumption.

Functional interplay between platelet activation and endothelial dysfunction in patients with coronary heart disease

Platelet-monocyte binding and surface P-selectin expression are sensitive markers of platelet activation. Endothelium-derived factors are known to inhibit platelet activation and may confer important anti-atherothrombotic effects. We assessed the relationship between platelet activation and endothelium-dependent vasomotion in patients with coronary heart disease (CHD). Twenty male patients with stable CHD were compared with 20 healthy men. Platelet-monocyte binding and platelet surface expression of P-selectin were assessed using two-colour flow cytometry on whole blood. Forearm blood flow was assessed in patients using venous occlusion plethysmography during intra-arterial infusions of substance P, acetylcholine and sodium nitroprusside. Platelet activation was higher in patients than healthy men (platelet-monocyte binding, 27 +/- 3 vs. 20 +/- 1%; P < 0.05). In patients with CHD, there was an inverse correlation between maximal substance P induced vasodilatation and both platelet-monocyte binding (P = 0.003) and P-selectin expression (P = 0.02). A similar correlation was observed between platelet-monocyte binding and the vasomotor response to acetylcholine (P = 0.08) but not with sodium nitroprusside. In patients with stable coronary heart disease, there is a strong inverse relationship between markers of platelet activation and endothelium-dependent vasomotor function. This may explain the pathophysiological mechanism linking endothelial vasomotor dysfunction and the risk of acute atherothrombotic events.

Nonmyocardial production of ST2 protein in human hypertrophy and failure is related to diastolic load

OBJECTIVES

This study was designed to investigate: 1) relationships between serum ST2 levels and hemodynamic/neurohormonal variables; 2) myocardial ST2 production; and the 3) expression of ST2, membrane-anchored ST2L, and its ligand, interleukin (IL)-33, in myocardium, endothelium, and leukocytes from patients with left ventricular (LV) pressure overload and congestive cardiomyopathy.

BACKGROUND

Serum levels of ST2 are elevated in heart failure. The relationship of ST2 to hemodynamic variables, source of ST2, and expression of ST2L and IL-33 in the cardiovascular system are unknown.

METHODS

Serum ST2 (pg/ml; median [25th, 75th percentile]) was measured in patients with LV hypertrophy (aortic stenosis) (n = 45), congestive cardiomyopathy (n = 53), and controls (n = 23). ST2 was correlated to N-terminal pro-brain natriuretic peptide, C-reactive protein, and hemodynamic variables. Coronary sinus and arterial blood sampling determined myocardial gradient (production) of ST2. The levels of ST2, ST2L, and IL-33 were measured (reverse transcriptase-polymerase chain reaction) in myocardial biopsies and leukocytes. The ST2 protein production was evaluated in human endothelial cells. The IL-33 protein expression was determined (immunohistochemistry) in coronary artery endothelium.

RESULTS

The ST2 protein was elevated in aortic stenosis (103 [65, 165] pg/ml, p < 0.05) and congestive cardiomyopathy (194 [69, 551] pg/ml, p < 0.01) versus controls (49 [4, 89] pg/ml) and correlated with B-type natriuretic peptide (r = 0.5, p < 0.05), C-reactive protein (r = 0.6, p < 0.01), and LV end-diastolic pressure (r = 0.38, p < 0.03). The LV ST2 messenger ribonucleic acid was similar in aortic stenosis and congestive cardiomyopathy versus control (p = NS). No myocardial ST2 protein gradient was observed. Endothelial cells secreted ST2. The IL-33 protein was expressed in coronary artery endothelium. Leukocyte ST2L and IL-33 levels were highly correlated (r = 0.97, p < 0.001).

CONCLUSIONS

In human hypertrophy and failure, serum ST2 correlates with the diastolic load. Though the heart, endothelium, and leukocytes express components of ST2/ST2L/IL-33 pathway, the source of circulating serum ST2 is extra-myocardial.

Relation of low response to clopidogrel assessed with point-of-care assay to periprocedural myonecrosis in patients undergoing elective coronary stenting for stable angina pectoris

Impaired responses to antiplatelet therapy assessed by laboratory tests are associated with an increased risk of recurrent ischemic events after percutaneous coronary intervention (PCI). This study was designed to determine the relation between responses to aspirin and clopidogrel as assessed by a point-of-care assay (Verify Now, Accumetrics, San Diego, California) and periprocedural myocardial infarction (PMI) in patients undergoing elective PCI for stable angina. One hundred twenty-two consecutive patients undergoing elective coronary stenting prospectively received aspirin 500 mg and clopidogrel 600 mg >or=12 hours before PCI. Clopidogrel response was measured with P2Y12 reaction units (PRUs) and percent inhibition P2Y12 from baseline (percent inhibition P2Y12) and aspirin response with aspirin reaction units (ARUs). Troponin T level was considered positive if it was >0.03 ng/ml. Responses to aspirin and clopidogrel were correlated (r=0.42, p <0.0001). PMI occurred in 27 patients (22%) who showed significantly lower percent inhibition P2Y12 (25.3+/-26 vs 38.3+/-25, p=0.01) and a trend toward higher PRU values (221+/-87 vs 193+/-94, p=0.21). We did not find any difference for aspirin response as assessed by ARUs in patients with or without PMI (460+/-82 vs 454+/-73, p = 0.82). Stratification of percent inhibition P2Y12 isolated a quartile of clopidogrel nonresponders (inhibition P2Y12 <15%) with significantly higher incidence of PMI (44% vs 15%, odds ratio 4.6, 95% confidence interval 1.9 to 11.5, p=0.001). In conclusion, point-of-care assessment of clopidogrel response reliably predicted PMI after low- to medium-risk elective PCI for stable angina.

Dietary intervention with oil rich fish reduces platelet-monocyte aggregation in man

BACKGROUND

Dietary intake of fish rich in omega-3 fatty acids is associated with a reduction in cardiovascular events. The mechanisms for this are uncertain and previous studies investigating effects on platelet function have produced inconsistent results. Platelet-monocyte aggregation is a sensitive marker of platelet activation and may contribute to the initiation and progression of atherothrombosis. This study assessed the effect of dietary intervention with oily fish on platelet-monocyte aggregation in healthy subjects.

METHODS

Fourteen subjects had their diet supplemented with 500 g of oil-rich fish per week for 4 weeks. A control group of 14 subjects received no dietary intervention over a 4-week period. Platelet-monocyte aggregates were assessed with flow cytometry.

RESULTS

Dietary intervention with fish led to an increase in omega-3 fatty acids in plasma phospholipids (14.2+/-3.4% versus 5.8+/-1.3%, P<0.001). In contrast to the control group, platelet-monocyte aggregates were reduced by 35% following dietary intervention with oily fish (16.0+/-9.0% versus 24.8+/-10.9%, P<0.01), and returned to basal levels 4 weeks after discontinuation of supplementation. There was an inverse correlation between platelet-monocyte aggregation and plasma omega-3 fatty acid concentrations (r=-0.421, P=0.006). There were no changes in the plasma markers of platelet activation, soluble P-selectin or soluble CD40 ligand.

CONCLUSIONS

We have demonstrated, for the first time, that dietary intervention with oil-rich fish reduces platelet-monocyte aggregation in man. Our results suggest that reduced platelet activation provides a potential mechanism through which fish oils confer their cardiovascular preventative benefits.

Coronary-subclavian steal syndrome: an usual cause of refractory unstable angina

A 73 year old woman, with previous history of coronary artery bypass grafting, was admitted for refractory unstable angina. The angiography revealed a significant stenosis of the ostium of the left subclavian artery. The patient underwent successful stenting of the subclavian artery and remained symptom free until hospital discharge a few days later.

Flow cytometric analysis of circulating platelet-monocyte aggregates in whole blood: methodological considerations

Platelet-monocyte aggregates are increasingly being used to quantify platelet activation. The variables that influence platelet-monocyte aggregates have not been well defined. We sought to determine the effect of blood collection, handling and processing techniques on detected levels of platelet-monocyte aggregates using a flow cytometric assay. Whole blood was labelled with anti-CD14-PE and anti-CD42a-FITC. Thereafter, samples were fixed and red cells lysed. Analysis was performed with the flow cytometer initially triggering on light scatter and then on FL-2 to identify CD14-PE positive monocytes. Platelet-monocyte aggregates were defined as monocytes positive for CD42a. The effect of collection, handling and processing techniques on this assay were assessed. Anticoagulation with heparin (20.1 +/- 2.0%), PPACK (16.8 +/- 1.9%), sodium citrate (12.3 +/- 1.6%) and EDTA (9.5 +/- 1.0%) resulted in markedly different levels of platelet-monocyte aggregation (P < 0.0001). Platelet-monocyte aggregation was higher in samples obtained from intravenous cannulae compared to those obtained by venepuncture (20.9 +/- 3.9% vs.13.8 +/- 2.4%, P = 0.03). For every 10 minutes of delay prior to processing platelet-monocyte aggregates increased by 2.8% (P = 0.0001) in PPACK anticoagulated blood and 1.7% (P = 0.01) in citrate anticoagulated blood. Erythrocyte lysis together with fixation does not affect platelet-monocyte aggregation. Platelet-monocyte aggregates remained stable over 24 hours when fixed and stored at 4 degrees C. Multiple handling and processing factors may affect platelet-monocyte aggregation. We recommend the measurement of platelet-monocyte aggregates on samples collected by direct venepuncture, using a direct thrombin inhibitor as the anticoagulant and minimising the time delay before sample fixation.

The effect of intensive lipid lowering on coronary atheroma and clinical outcome

The association between raised plasma cholesterol and cardiovascular risk is well established, with consistent evidence associating LDL-cholesterol reduction with a reduction in primary and secondary cardiovascular events. It is believed that intensive lipid lowering may improve clinical outcomes further by acting to stabilise plaque and preventing plaque progression, ultimately reducing plaque vulnerability. However, it remains uncertain whether a continued clinical benefit occurs with intensive lipid lowering or if there is a threshold level below which no further benefit occurs.

Promotion of proinflammatory interactions between platelets and monocytes by unfractionated heparin

OBJECTIVES

To determine the in vitro effects of unfractionated heparin, fractionated heparin and direct thrombin inhibition on platelet-monocyte aggregation, and to establish the in vivo effects of unfractionated heparin and direct thrombin inhibition on platelet-monocyte aggregates in patients scheduled for percutaneous coronary intervention (PCI).

DESIGN

Platelet-monocyte aggregates were assessed in whole blood from 18 healthy volunteers after the addition of unfractionated heparin (1 U/ml), enoxaparin (0.8 U/ml) or lepirudin (5.6 microg/ml), and in 28 patients scheduled for elective PCI before and after administration of 100 U/kg of unfractionated heparin or 0.75 mg/kg bivalirudin. The influence of P-selectin-mediated platelet-monocyte aggregation was assessed with specific blocking antibodies.

RESULTS

Addition of unfractionated heparin in vitro was associated with a higher level of platelet-monocyte aggregates than in controls (20.1 (1.9)% v 16.2 (1.6)%, respectively, p < 0.001). However, platelet-monocyte aggregation was not affected by enoxaparin or lepirudin (16.9 (2.0)% and 17.0 (2.2)%, respectively, NS). Intravenous unfractionated heparin in vivo also resulted in an increase in platelet-monocyte aggregates (absolute Delta 7.1 (2.7)%, p < 0.01), whereas intravenous bivalirudin had no effect (absolute Delta -1.5 (2.4)%, NS). The addition of P-selectin blockade abolished any increase in platelet-monocyte aggregates associated with heparin.

CONCLUSIONS

In vitro and in vivo unfractionated heparin is associated with increased platelet-monocyte aggregation through a P-selectin-dependent mechanism. These findings provide a potential explanation for the superior cardiovascular outcomes associated with fractionated heparins and direct thrombin inhibitors.

Increased CD40 ligand and platelet–monocyte aggregates in patients with type 1 diabetes mellitus

BACKGROUND

Diabetes mellitus is a major risk factor for cardiovascular disease and is associated with a proinflammatory and prothrombotic state. We investigated whether CD40 ligand (L) expression and platelet-monocyte aggregation are increased in patients with type 1 diabetes.

METHODS

Serum C-reactive protein (CRP) and soluble (s) CD40L concentrations, platelet surface CD40L expression and platelet-monocyte aggregates were measured in 22 patients with uncomplicated type 1 diabetes and 22 age- and sex-matched non-diabetic control subjects.

RESULTS

In comparison to controls, patients with type 1 diabetes had higher serum CRP concentrations (3.29 +/- 0.9 mg/L versus 0.99 +/- 0.2mg/L, P = 0.01), serum sCD40L concentrations (10.0 +/- 1.4 ng/mL versus 4.6 +/- 0.6 ng/mL, P = 0.006), and platelet surface expression of CD40L (13.8 +/- 0.9% versus 8.5 +/- 1.1%, P < 0.001). Platelet-monocyte aggregates were also significantly elevated in type 1 diabetes (35.9 +/- 3.3% versus 26.4 +/- 2.9%, P = 0.005; n = 10). We also observed a significant correlation between plasma glucose and serum CRP (r = 0.53, P = 0.01) as well as platelet-monocyte aggregates (r = 0.69, P = 0.03).

CONCLUSIONS

Type 1 diabetes is associated with increased CD40L expression and platelet-monocyte aggregation, which may contribute to the proinflammatory and prothrombotic state as well as the accelerated atherogenesis associated with this disorder.