Imaging in patients after cardiac transplantation and in patients with ventricular assist devices

Expanding the Scope of Multimodality Imaging in Durable Mechanical Circulatory Support

An increasing number of patients transition to advanced-stage heart failure refractory to medical therapy. Left ventricular assist systems (LVAS) provide a bridge to candidates awaiting heart transplantation and extended device durability allows permanent implantation referred to as destination therapy. Noninvasive imaging plays a pivotal role in the optimal management of patients implanted with durable mechanical circulatory support (MCS) devices. Several advances require an updated perspective of multi-modality imaging in contemporary LVAS management. First, there has been substantial evolution of devices such as the introduction of the fully magnetically levitated HeartMate 3 pump (Abbott, Abbott Park, Illinois). Second, imaging beyond the device, of the peripheral system, is increasingly recognized as clinically relevant. Third, U.S. Food and Drug Administration recalls have called attention to LVAS complications beyond pump thrombosis that are amenable to imaging-based diagnosis. Fourth, there is increased availability of multimodality imaging, such as computed tomography and positron emission tomography, at many centers across the world. In this review, the authors provide a practical and contemporary approach to multi-modality imaging of current-generation durable MCS devices. As the use of LVAS and other novel MCS devices increases globally, it is critical for clinicians caring for LVAS patients to understand the roles of various imaging modalities in patient evaluation and management.

Anti-inflammatory properties of amniotic membrane patch following pericardiectomy for constrictive pericarditis

BACKGROUND

Since constrictive pericarditis is most often idiopathic and the pathophysiology remains largely unknown, both the diagnosis and the treatment can be challenging. However, by definition, inflammatory processes are central to this disease process. Amniotic membrane patches have been shown to possess anti-inflammatory properties and are believed to be immune privileged. Due to these properties, amniotic membrane patches were applied intraoperatively in a complicated patient presenting with constrictive pericarditis.

CASE PRESENTATION

A patient with a history of multiple cardiac surgeries presented with marked fatigue, worsening dyspnea and sinus tachycardia. He was found to have constrictive physiology during cardiac catheterization, with cardiac MRI demonstrating hepatic vein dilatation, atrial enlargement and ventricular narrowing. After amniotic membrane patch treatment and pericardiectomy, post-operative cardiac MRI failed to demonstrate any appreciable pericardial effusion or inflammation, with no increased T2 signal that would suggest edema.

CONCLUSIONS

Given the positive results seen in this complex patient, we suggest continued research into the beneficial properties of amniotic membrane patches in cardiac surgery.

Transplant allograft vasculopathy: Role of multimodality imaging in surveillance and diagnosis

Cardiac allograft vasculopathy (CAV) is a challenging long-term complication of cardiac transplantation and remains a leading long-term cause of graft failure, re-transplantation, and death. CAV is an inflammatory vasculopathy distinct from traditional atherosclerotic coronary artery disease. Historically, the surveillance and diagnosis of CAV has been dependent on serial invasive coronary angiography with intravascular imaging. Although commonly practiced, angiography is not without significant limitations. Technological advances have provided sophisticated imaging techniques for CAV assessment. It is now possible to assess the vascular lumen, vessel wall characteristics, absolute blood flow, perfusion reserve, myocardial contractile function, and myocardial metabolism and injury in a noninvasive, expeditious manner with little risk. The current article will review key imaging modalities for the surveillance, diagnosis, and prognosis of CAV and discuss coronary physiology of transplanted hearts with emphasis on the clinical implications for provocative and vasodilator stress testing.