Ideal Antiplatelet Therapy for Coronary Artery Disease: Focus on Adenosine Diphosphate Receptor Inhibitors

EBUS-TBNA and EUS-FNA: Risk Assessment for Patients Receiving Clopidogrel

BACKGROUND

Clopidogrel is widely used for the prevention of thrombotic vascular complications. Its primary potential toxicity is bleeding. Management of clopidogrel therapy for patients undergoing invasive procedures is an area of ongoing study. We sought to evaluate the bleeding risk for patients undergoing needle aspiration biopsy by endobronchial ultrasound (EBUS) or esophageal ultrasound (EUS) while taking clopidogrel.

METHODS

Retrospective review of sequential cases of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and esophageal ultrasound fine needle aspiration (EUS-FNA).

RESULTS

Three hundred ninety-five consecutive procedures were reviewed. Thirty-seven patients were taking clopidogrel at time of biopsy. The patients taking clopidogrel were significantly older than those in the control group. Two patients (1%) in the control group were admitted for observation, but neither was found to have a significant bleed. There were no clinically significant bleeding complications in either of the study groups.

CONCLUSIONS

It is reasonable to proceed with EBUS-TBNA or EUS-FNA when both, (1) clopidogrel cannot be stopped and, (2) an important diagnostic question is at stake.

Cardiac purinergic signalling in health and disease

This review is a historical account about purinergic signalling in the heart, for readers to see how ideas and understanding have changed as new experimental results were published. Initially, the focus is on the nervous control of the heart by ATP as a cotransmitter in sympathetic, parasympathetic, and sensory nerves, as well as in intracardiac neurons. Control of the heart by centers in the brain and vagal cardiovascular reflexes involving purines are also discussed. The actions of adenine nucleotides and nucleosides on cardiomyocytes, atrioventricular and sinoatrial nodes, cardiac fibroblasts, and coronary blood vessels are described. Cardiac release and degradation of ATP are also described. Finally, the involvement of purinergic signalling and its therapeutic potential in cardiac pathophysiology is reviewed, including acute and chronic heart failure, ischemia, infarction, arrhythmias, cardiomyopathy, syncope, hypertrophy, coronary artery disease, angina, diabetic cardiomyopathy, as well as heart transplantation and coronary bypass grafts.

Advances in antiplatelet technologies to improve cardiovascular disease morbidity and mortality: a review of ticagrelor

Antiplatelet therapy is widely used with proven benefit for the prevention of further ischemic cardiac complications in patients with acute coronary syndrome. Treatment guidelines for acute coronary syndrome and percutaneous coronary intervention now recommend the use of oral antiplatelet agents including ticagrelor, prasugrel, or clopidogrel in combination with aspirin to comprise dual antiplatelet therapy for the prevention of recurrent ischemic events. The limitations of conventional antiplatelet therapy with clopidogrel or prasugrel include the potential for low response to clopidogrel identified through platelet reactivity or genetic testing, increased risk of bleeding with prasugrel, or slower return to normal platelet activity in patients who received either prasugrel or clopidogrel prior to emergent or planned surgical procedures. This review will discuss the pharmacokinetic and pharmacodynamic properties of ticagrelor in comparison to conventional P2Y12 receptor inhibitors and its utility in patients identified as low responders to clopidogrel. Completed clinical studies and substudies comparing ticagrelor to clopidogrel and ongoing clinical trials evaluating ticagrelor in acute coronary syndrome patients will also be reviewed.