The role of fondaparinux as an adjunct to thrombolytic therapy in acute myocardial infarction: a subgroup analysis of the OASIS-6 trial.

AIMS: No antithrombotic therapy has been shown to reduce mortality when used with thrombolytics in acute myocardial infarction (AMI). In the OASIS-6 trial, fondaparinux significantly reduced mortality and reinfarction without increasing bleeding in 12 092 patients with acute ST elevation MI. METHODS AND RESULTS: We report the results of a subgroup analysis in the 5436 patients (45%) receiving thrombolytics. According to local practice, 4415 patients did not have an indication for unfractionated heparin (stratum 1) and 1021 did (stratum 2). Fondaparinux reduced the primary study outcome of death or MI at 30 days [Hazard ratio (HR) 0.79, 95% confidence interval (CI) 0.68-0.92] with consistent reductions in both mortality (HR and CI) and reinfarction (HR and CI). There was a non-significantly lower rate of stroke (HR 0.77, CI 0.48-1.25). The risk of severe bleeding was significantly reduced (HR 0.62, CI 0.40-0.94), and thus the balance of benefit and risk (death, MI and severe haemorrhage) was clearly reduced by fondaparinux (HR 0.77, 95% CI 0.67-0.90). Results were consistent in the two strata, by the different types of thrombolytics and across various time intervals from symptom onset to treatment. CONCLUSION: In STEMI patients treated with thrombolytic agents (predominantly streptokinase), fondaparinux significantly reduced the risk of death, re-MI and severe bleeds.     

Increased coagulation factor XIII activity but not genetic variants of coagulation factors is associated with myocardial infarction in young patients

Journal of Thrombosis and Thrombolysis - The aim of the study was to investigate the possible role of coagulation factor XIII (FXIII) plasma activity and its gene (F13A1) Val34Leu variant as well...     

Combining warfarin and antiplatelet therapy after coronary stenting in the Global Registry of Acute Coronary Events: is it safe and effective to use just one antiplatelet agent?

AIMS: To identify factors associated with the use of single or dual antiplatelet therapy in patients prescribed warfarin following coronary stenting and to investigate whether single (aspirin or thienopyridine) vs. dual antiplatelet therapy plus warfarin leads to an excess of adverse outcomes. METHODS AND RESULTS: We analysed data from 800 patients with an acute coronary syndrome who underwent coronary stenting (130 patients received a drug-eluting stent) and were discharged on warfarin and either dual (n = 580) or single (n = 220) antiplatelet therapy. The use of single antiplatelet therapy was more common in Europe than in the USA (34 vs. 17%, P < 0.001). There was no difference in major bleeding in hospital or in 6-month mortality or myocardial infarction. In the single antiplatelet group, the use of either aspirin or thienopyridine (clopidogrel or ticlopidine) in combination with warfarin resulted in similar outcomes. CONCLUSION: Use of single vs. dual antiplatelet therapy and warfarin following stenting is common. In this observational study, there was no difference in mortality or myocardial infarction at 6 months; however, larger trials are needed to assert any firm recommendations.     

Right ventricular dysfunction and exercise capacity after inferior (posterior) wall acute myocardial infarction

Tissue Doppler echocardiography is a novel technique that can be used to diagnose right ventricular (RV) systolic dysfunction. Until recently, there have been no data on the influence of tissue Doppler-derived RV systolic dysfunction on exercise capacity after inferior (posterior) myocardial infarction (MI). We studied 90 consecutive patients (76% men, mean age 61 ± 10 years) with first inferior ST-segment elevation MI and left ventricular ejection fraction ≥45%. RV systolic dysfunction was defined as RV systolic myocardial velocity <11.5 cm/s at the basal segment of the RV free wall assessed by pulse tissue Doppler. Patients were categorized as with or without RV systolic dysfunction (RV systolic myocardial velocity 9.34 ± 1.36 and 13.74 ± 1.58 cm/s, respectively). A cardiopulmonary exercise test was performed before or soon after discharge (day 14 ± 10). Patients with RV systolic dysfunction had lower oxygen consumption assessed as percent predicted oxygen uptake in liters per minute and milliliters per kilogram per minute at their anaerobic threshold (61 ± 11% vs 69 ± 17%, p = 0.007; 53 ± 12% vs 61 ± 19%, p = 0.012, respectively) and at peak exercise (71 ± 12% vs 83 ± 16%, p = 0.0001; 62 ± 14% vs 74 ± 21%, p = 0.002, respectively). Multivariate regression analysis revealed that the following independent factors negatively influenced exercise capacity: RV systolic dysfunction, female gender, age, lower body mass index, current smoking, and maximal troponin I concentration. In conclusion, we found decreased exercise capacity in patients with systolic RV dysfunction assessed by pulse tissue Doppler in patients with inferior (posterior) wall acute MI despite preserved left ventricular function.