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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.Twenty cigarette smokers were recruited into a randomised, double-blind, placebo-controlled, crossover trial of ω-3 fatty acid supplementation.ω-3 fatty acid supplements (2 g/day) or placebo for a 6-week period.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.All vasodilators caused dose-dependent increases in FBF (p0.0001). 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 (p0.0001) 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.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.

OBJECTIVES--To compare the use of cylindrical balloons and the Inoue balloon for percutaneous mitral valvotomy in patients in the United Kingdom. DESIGN--Comparison of the haemodynamic results, complications, and symptomatic outcome of balloon dilatation for mitral stenosis in consecutive patients treated by cylindrical balloons and a second consecutive series of patients treated by the Inoue balloon. SETTING--A tertiary cardiac referral centre in Scotland. PATIENTS--70 patients (mean age 60.6 years) treated by the single or double cylindrical balloon technique and 70 patients (mean age 58.9 years) treated with the Inoue balloon method. MAIN OUTCOME MEASURES--Success in obtaining dilatation at the mitral orifice, procedure and screening times, increase in valve area, complications, and early symptomatic outcome. RESULTS--Dilatation of the mitral valve was obtained in 91% of patients when cylindrical balloons were used and in 99% of patients treated with the Inoue balloon. Use of the Inoue balloon gave significantly shorter procedure and screening times. Technical problems in obtaining and maintaining the position at the mitral orifice were more common with cylindrical balloons. Improvements in valve area and symptoms were not significantly different with use of the two types of balloon. The Inoue balloon avoided cardiac tamponade and the creation of larger atrial septal defects, but had a higher incidence of increase in mitral reflux. CONCLUSIONS--In these elderly patients, the Inoue balloon method was safer and faster for percutaneous mitral valvotomy, with a higher success rate for dilatation within the valve orifice. Haemodynamic and symptomatic improvement was similar with the two techniques.

Background The risk of acute myocardial infarction in firefighters is increased during fire suppression duties, and is likely to reflect a combination of factors including extreme physical exertion and heat exposure. We assess the effects of physical exertion and heat exposure on vascular function and thrombosis in firefighters. Methods In an open label randomised cross-over study, seventeen healthy, non-smoking firefighters (age 41 ± 7 years, 15 male) performed a standardised training exercise in a fire simulation facility (average temperature 400°C) or a sham exposure for 20mins. Bilateral forearm blood flow was measured before and during unilateral intra-brachial infusion of acetylcholine (5–20 µg/min), sodium nitroprusside (2–8 µg/min) and verapamil (10–100 µg/min) 2–4 h after exposure. Thrombus formation and platelet activation was measured using the Badimon chamber at 2 hrs and by flow cytometry of whole blood immediately following and 24 hrs after each exposure. Results Following fire simulation training, core temperature in firefighters increased by 1.2 ± 0.48°C and weight was reduced by 0.46 ± 0.14 kg (P 2 , 95% CI 3,006–7,009 μm 2 ) and 58% (change in thrombus area 5,582 μm 2 , 95% CI 1,795–9369 μm 2 ) respectively. This was associated with an increase in platelet-monocyte binding of 21% (absolute change 7%, 95% CI 0.8–13%, P = 0.03) from baseline following fire simulation training. Conclusions Exposure to extreme heat and physical exertion during fire suppression impairs vascular function and increases thrombus formation in healthy firefighters. Our findings suggest pathogenic mechanisms to explain the association between fire suppression activity and acute myocardial infarction in firefighters.

Background Non-invasive imaging to identify vulnerable or ruptured coronary artery plaque would represent a major clinical advance. Using positron emission tomography (PET) and computed tomography (CT), we investigated coronary uptake of 18F-fluoride (18F-NaF) and 18F-fluorodeoxyglucose (18F-FDG) in patients with acute myocardial infarction or stable angina. Methods Forty patients with acute myocardial infarction and 40 with stable angina underwent electrocardiogram-gated 18F-NaF and 18F-FDG PET-CT and invasive coronary angiography. 18F-NaF uptake was compared with virtual histology intravascular ultrasound in patients with stable angina, and with histology in 12 carotid endartectomy specimens. Results Intense focal 18F-NaF uptake occurred at the site of plaque rupture in 37 (93%) patients with myocardial infarction (tissue-to-background ratio [TBR], 1.66 [1.40–2.25] versus 1.24 [1.06–1.38]; culprit versus maximal non-culprit, P Conclusions 18F-NaF holds major promise as a novel biomarker of coronary plaque vulnerability and rupture with implications for the diagnosis, investigation and treatment of coronary artery disease.

Background Smokers treated with thrombolysis for acute ST elevation myocardial infarction (STEMI) have a higher frequency of reperfusion and lower in-hospital mortality when compared to non-smokers. We examined the effects of smoking status on angiographic outcome, in-hospital and 12-month mortality following primary percutaneous coronary intervention in patients presenting with STEMI. Methods We examined the effect of smoking status on clinical and angiographic outcomes in 228 patients with STEMI undergoing primary percutaneous coronary intervention in South East Scotland over a 12-month-period. Results The study population was predominantly male (66%) with a mean age of 61 years (range 29–93). Patients who smoked were younger than ex-smokers or non-smokers (57±12 vs 66±12 vs 65±15 years respectively, p Conclusions In patients presenting with STEMI, primary percutaneous coronary intervention is associated with high rates of reperfusion in the infarct-related artery and low 12-month mortality, irrespective of smoking status. The “smokers paradox” observed with thrombolytic therapy does not extend to patients treated with primary percutaneous coronary intervention for STEMI. These findings provide support for the hypothesis that the smokers paradox can be explained by a defect in endogenous fibrinolytic activity induced by smoking.