Sub-therapeutic colchicine levels in a patient treated for acute pericarditis in the setting of carbamazepine use: A case report.

WHAT IS KNOWN AND OBJECTIVE: Colchicine is a standard therapy for the treatment of acute pericarditis. It is metabolized by cytochrome P-450 3A4 (CYP3A4) and is subject to potential drug interactions. Multiple case reports describe accumulation of colchicine with CYP3A4 inhibitors, but limited data exist for increased colchicine clearance with CYP3A4 inducers. We describe a case of idiopathic haemorrhagic pericarditis treated with colchicine but rendered ineffective given potential drug interaction with carbamazepine. CASE SUMMARY: A 61-year-old man with a history of seizures presented to the emergency department with severe chest pain radiating to the back and was found to have a large pericardial effusion. The patient underwent pericardiocentesis, which demonstrated a haemorrhagic pericardial effusion. After an extensive workup, he was treated for idiopathic pericarditis with anti-inflammatories and colchicine but failed to improve despite adequate colchicine loading and maintenance dosing. A serum colchicine level was checked given a potential CYP3A4 drug interaction in the setting of chronic carbamazepine use and was found to be sub-therapeutic. Concomitant use of CYP3A4 inducers in the setting of colchicine use can render anti-inflammatory strategies ineffective and may result in treatment failure. WHAT IS NEW AND CONCLUSION: Due to its hepatic and intestinal metabolism by CYP3A4 enzymes, colchicine is susceptible to drug-drug interactions resulting in either toxicities or rendering it ineffective with concomitant CYP3A4 inhibitors or inducers, respectively. Carbamazepine, a common anti-epileptic medication and known inducer of the CYP3A4 enzyme, may reduce levels of colchicine in the blood resulting in treatment failure. Further study is required to determine if dose adjustments may overcome this drug interaction.

3D printing tissue-mimicking materials for realistic transseptal puncture models.

Applications of additive manufacturing (commonly referred to as 3D printing) in direct fabrication of models for pre-surgical planning, functional testing, and medical training are on the rise. However, one current limitation to the accuracy of models for cardiovascular procedural training is a lack of printable materials that accurately mimic human tissue. Most of the available elastomeric materials lack mechanical properties representative of human tissues. To address the gap, the authors explore the multi-material capability of material jetting additive manufacturing to combine non-curing and photo-curing inks to achieve material properties that more closely replicate human tissues. The authors explore the impact of relative material concentration on tissue-relevant properties from puncture and tensile testing under submerged conditions. Further, the authors demonstrate the ability to mimic the mechanical properties of the fossa ovalis, which proves beneficial for accurately simulating transseptal punctures. A fossa ovalis mimic was printed and assembled within a full patient-specific heart model for validation, where it exhibited accuracy in both mechanical properties and geometry. The explored material combination provides the opportunity to fabricate future medical models that are more realistic and better suited for pre-surgical planning and medical student training. This will ultimately guide safer, more efficient practices.

A case series: alternative access for refractory shock during cardiac arrest.

BACKGROUND: In patients with iliofemoral arterial disease, transcaval and percutaneous axillary artery access are safe alternatives for delivery of transcatheter aortic valve replacement for severe aortic stenosis. In the setting of cardiac arrest, arterial access is crucial for delivery of mechanical circulatory support devices such as an Impella CP® or cannulation for extracorporeal cardiopulmonary resuscitation (ECMO). We report the use of transcaval and axillary artery access in three cases of cardiac arrest in which the emergent placement of an Impella CP® (Abiomed, Danvers, MA, USA) or cannulation for ECMO was instrumental in resuscitation from refractory cardiac arrest. CASE SUMMARY: The first patient is a 59-year-old woman who developed ventricular fibrillation arrest after percutaneous intervention with emergent placement of a transcaval Impella CP®. In the second case, a 67-year-old man with coronary vasospasm developed cardiac arrest with an axillary artery Impella CP® placed. The third case highlights a 67-year-old man who developed cardiac arrest 1 day after unsuccessful chronic total occlusion repair requiring ECMO cannulation to his axillary artery. All three patients achieved spontaneous circulation after placement of assist devices. DISCUSSION: To our knowledge, a case report of transcaval or percutaneous axillary artery access for Impella CP® during cardiac arrest has not been published. While the long-term prognosis following cardiac arrest is poor, younger patients deserve every chance for survival with rapid cardiopulmonary support by alternative access if necessary. Advanced large bore alternative access techniques should be learned by all interventional operators.

Radial artery pseudoaneurysm: a simplified treatment method.

A radial artery pseudoaneurysm represents a rare, potentially catastrophic complication of arterial cannulation that has been reported after cardiac catheterization. Treatment options are limited to chemical, mechanical, and combined approaches to obliterate the radial artery pseudoaneurysm and tract. Manual compression protocols using the TR Band (Terumo Medical Corporation, Somerset, NJ) have been variable and anecdotal, without objective measurements of adequate compression, making this technique prone to failure. In this report, we present an efficient, safe, and noninvasive management protocol using a pulse oximeter and the TR Band for treatment of radial artery pseudoaneurysms that is cost-effective and efficient and ensures correction without occlusion of the radial artery.