Right Ventricular Dysfunction in Myocardial Infarction: A New Risk Factor for Clopidogrel Resistance?

Introduction:

Right ventricular dysfunction (RVD) in acute coronary syndromes occur either primary in infarction of the right ventricle mainly caused by proximal occlusion of the right coronary artery or secondary ininfarction of the left ventricle with consecutive increase of pulmonary pressure. The incidence of right myocardial infarction has ranged w

idely according to the diagnostic technique used and the patients profile. It is recognizable clinically in two thirds of hypotensive inferior infarction and most inferior infarctions with cardiogenic shock. 

The recommended treatment in acute myocardial infarction is percutaneous coronary intervention (PCI) with stent deployment in order to restore myocardial perfusion . Dual inhibition of platelet aggregation with a thienopyridine like clopidogrel andaspirin showed a dramatic reduction of major adverse cardiac events after PCI .In the past years there have been several studies that showed the importance of sufficient response to clopidogrel to prevent thrombembolic complications. 

Furthermore, different studies showed the importance of an early detection of clopidogrel resistance as it is associated with worse outcome after PCI .

Since clopidogrel is a prodrug, which has to be metabolized into the active metabolite by two Cytochrome P-450 dependent steps in the liver, the inter individual variability for the responsiveness to clopidogrel is high. Especially in hemodynamically unstable patients with cardiogenic shock and multi organ dysfunction resorption and metabolization of clopidogrel may not be ensured.