Jeffrey M. Miller

Implications of bleeding in acute coronary syndrome and percutaneous coronary intervention

The advent of potent antiplatelet and antithrombotic agents over the past decade has resulted in significant improvement in reducing ischemic events in acute coronary syndrome (ACS). However, the use of antiplatelet and antithrombotic combination therapy, often in the settings of percutaneous coronary intervention (PCI), has led to an increase in the risk of bleeding. In patients with non-ST elevation myocardial infarction treated with antithrombotic agents, bleeding has been reported to occur in 0.4%–10% of patients, whereas in patients undergoing PCI, periprocedural bleeding occurs in 2.2%–14% of cases. Until recently, bleeding was considered an intrinsic risk of antithrombotic therapy, and efforts to reduce bleeding have received little attention. There have been increasing data demonstrating that bleeding is associated with adverse outcomes, including myocardial infarction, stroke, and death. Therefore, it is imperative to optimize patient outcomes by adopting pharmacological and nonpharmacological strategies to minimize bleeding while maximizing treatment efficacy. In this paper, we present a review of the bleeding classifications used in large-scale clinical trials in patients with ACS and those undergoing PCI treated with antiplatelets and antithrombotic agents, adverse outcomes, particularly mortality associated with bleeding complications, and suggested predictive risk factors. Potential mechanisms of the association between bleeding and mortality and strategies to reduce bleeding complications are also discussed.

Antithrombotic strategies in patients undergoing percutaneous coronary intervention for acute coronary syndrome

In patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS), both periprocedural acute myocardial infarction and bleeding complications have been shown to be associated with early and late mortality. Current standard antithrombotic therapy after coronary stent implantation consists of lifelong aspirin and clopidogrel for a variable period depending in part on the stent type. Despite its well-established efficacy in reducing cardiac-related death, myocardial infarction, and stroke, dual antiplatelet therapy with aspirin and clopidogrel is not without shortcomings. While clopidogrel may be of little beneficial effect if administered immediately prior to PCI and may even increase major bleeding risk if coronary artery bypass grafting is anticipated, early discontinuation of the drug may result in insufficient antiplatelet coverage with thrombotic complications. Optimal and rapid inhibition of platelet activity to suppress ischemic and thrombotic events while minimizing bleeding complications is an important therapeutic goal in the management of patients undergoing percutaneous coronary intervention. In this article we present an overview of the literature on clinical trials evaluating the different aspects of antithrombotic therapy in patients undergoing PCI and discuss the emerging role of these agents in the contemporary era of early invasive coronary intervention. Clinical trial acronyms and their full names are provided in Table 1.

Thrombotic microangiopathy following pancreas after kidney transplants

Abstract:  Advances in immunosuppressive therapy and refinement in surgical techniques have allowed pancreas after kidney (PAK) transplantation to become a viable therapeutic option for patients with brittle type I diabetic recipients of a living donor or previous deceased kidney alone transplant. Although maintenance immunosuppressive therapy is not significantly changed after the addition of a pancreas, a temporary booster in immunosuppressive therapy and an increase in the dose of calcineurin inhibitor (CNI) are required after PAK transplantation. The latter has been implicated in the observed variable decline in kidney allograft function. We herein report two cases of kidney allograft dysfunction following PAK transplant due to biopsy‐proven transplant, thrombotic microangiopathy (TMA). Whether PAK transplantation pre‐disposes a subset of patients to the development of post‐transplant TMA is not known. Diagnostic kidney biopsies should be considered in PAK transplant recipients with worsening kidney allograft function.

The Case of the Missed Physical Examination: Testicular Carcinoma Presenting As a GI Bleed

Introduction Testicular germ cell tumors (GCTs) are the most common malignancy in young men aged 15 to 35 and represents approximately 1% of malignancies in men in the United States. In most cases, GCTs present as a painless testicular mass. However, 30% of patients initially endorse symptoms of flank pain, abdominal pain, shortness of breath, hemoptysis, and in rare cases, occult GI bleeding suggestive of metastatic disease to the lungs and retroperitoneal lymph nodes. We report a rare case of occult GI bleeding as the presenting symptom for GCT. In young men, it is important to recognize metastatic testicular tumor as part of the differential diagnosis when investigating causes of a GI bleed.

Delayed hyperacute rejection in a patient who developed clostridium difficile infection after ABO-incompatible kidney transplantation

Over the past decade ABO incompatible transplantation has emerged as an important potential source for increasing living kidney transplantation in selected transplant centers. Early reports suggest that patients who have elevated serum anti-blood group antibody titers (anti-A/B) before transplantation and a rebound antibody production after antibody removal may be at high immunological risk. With currently available immune modulation protocols and immunosuppressive therapy, excellent short- and long-term patient and graft survival rates have been achieved even in those with high anti-A/B antibody titers before plasmapheresis or immunoadsorption. Nonetheless, acute infection with an organism possessing surface markers analogous to blood group antigens such as carbohydrate structures on the surface of bacterial cell wall occurring before the firm establishment of accommodation can trigger the onset of acute antibody-mediated rejection. We herein report a case of delayed hyperacute rejection in an A1 to O, ABO incompatible transplant recipient following an episode of Clostridium difficile infection.