Percutaneous devices for stroke prevention

Novel nonpharmacologic approaches for stroke prevention in atrial fibrillation: results from clinical trials

Atrial fibrillation (AF), the most common cardiac arrhythmia, confers a 5-fold risk of stroke that increases to 17-fold when associated with mitral stenosis. At this time, the most effective long-term solution to protect patients from stroke and thromboembolism is oral anticoagulation, either with vitamin K antagonists (VKAs) or a novel oral anticoagulant (NOAC). Despite the significant benefits they confer, both VKAs and NOACs are underused because of their increased potential for bleeding, and VKAs are underused because of their narrow therapeutic range, need for regular international normalized ratio checks, and interactions with food or medications. In patients with nonvalvular AF, approximately 90% of strokes originate from the left atrial appendage (LAA); in patients with rheumatic mitral valve disease, many patients (60%) have strokes that originate from the left atrium itself. Surgical LAA amputation or closure, although widely used to reduce stroke risk in association with cardiac surgery, is not currently performed as a stand-alone operation for stroke risk reduction because of its invasiveness. Percutaneous LAA closure, as an alternative to anticoagulation, has been increasingly used during the last decade in an effort to reduce stroke risk in nonvalvular AF. Several devices have been introduced during this time, of which one has demonstrated noninferiority compared with warfarin in a randomized controlled trial. This review describes the available technologies for percutaneous LAA closure, as well as a summary of the published trials concerning their safety and efficacy in reducing stroke risk in AF.

Percutaneous implantation of a second device in patients with residual right-to-left shunt after patent foramen ovale closure

INTRODUCTION

The management of patients with residual right-to-left shunt (rRLS) after percutaneous patent foramen ovale (PFO) closure is debated. The aim of this study was to define the incidence of moderate-to-large rRLS and to report the feasibility, safety and long-term clinical outcome of transcatheter closure of rRLS.

METHODS AND RESULTS

From June 2000 to March 2013, 322 subjects underwent percutaneous PFO closure. In 39 patients (12.1%) with moderate-to-large rRLS on transcranial Doppler (TCD) and/or transesophageal echocardiogram a second cardiac catheterization was performed with the aim of completing the closure. A second closure device was implanted in 21 patients (53.8%). In the remaining 18 (46.2%), a second device was not delivered for the following reasons: in 13 (72.2%) no residual passage could be crossed, in 5 (27.8%) the residual shunt was deemed to be negligible. No complications occurred. After the second procedure, complete closure was proved by TCD in 16/21 (76.2%) subjects. One patient received a third device. During follow-up (41 ± 19 months), no cerebrovascular ischemic accidents occurred.

CONCLUSION

A second percutaneous PFO occlusion device can be safely implanted in patients with significant rRLS. However, a moderate-to-large rRLS on TCD and/or TEE may not necessarily represent a significant risk of further paradoxical embolization.

Percutaneous treatment of patients with heart diseases: selection, guidance and follow-up. A review

Aortic stenosis and mitral regurgitation, patent foramen ovale, interatrial septal defect, atrial fibrillation and perivalvular leak, are now amenable to percutaneous treatment. These percutaneous procedures require the use of Transthoracic (TTE), Transesophageal (TEE) and/or Intracardiac echocardiography (ICE). This paper provides an overview of the different percutaneous interventions, trying to provide a systematic and comprehensive approach for selection, guidance and follow-up of patients undergoing these procedures, illustrating the key role of 2D echocardiography.

Prevention of Stroke in Patients with Patent Foramen Ovale

Patent foramen ovale is found in 24% of healthy adults and 38% of patients with cryptogenic stroke. This ratio and case reports indicate that patent foramen ovale and stroke are associated, probably because of paradoxical embolism. In healthy people with patent foramen ovale, embolic events are not more frequent than in controls, and therefore no primary prevention is needed. However, once ischaemic events occur, the risk of recurrence is substantial and prevention becomes an issue. Acetylsalicylic acid and warfarin reduce this risk to the same level as in patients without patent foramen ovale. Patent foramen ovale with a coinciding atrial septal aneurysm, spontaneous or large right-to-left shunt, or multiple ischaemic events potentiates the risk of recurrence. Transcatheter device closure has therefore become an intriguing addition to medical treatment, but its therapeutic value still needs to be confirmed by randomised-controlled trials.

Future Developments in Nonsurgical Epicardial Therapies

The unique anatomic position of the pericardium in juxtaposition to central cardiac structures enables it to serve as the ideal vantage point for the delivery of novel cardiovascular therapies. Development of new tools to permit delivery of therapy in the closed pericardial space holds promise for near-surgical access to the heart, without open surgical morbidity. Early observations raise hope for the availability of epicardial leads to enhance cardiac resynchronization therapy designed for subxiphoid nonsurgical percutaneous delivery. Emerging technologies for left atrial appendage ligation may offer new strategies for preventing stroke.

The role of the out-of-operating room anesthesiologist in the care of the cardiac patient

Modern invasive cardiovascular procedures require patients to be both comfortable and cooperative. In addition, these procedures demand the complete attention of the attending cardiovascular specialist, and, to a large degree, the outcomes of these procedures depend on the amount of focus and concentration the cardiovascular specialist can give to performing the procedure itself. A team approach using the specialized skills of a cardiologist and an anesthesiologist frequently is required to optimize results. This article clearly delineates the procedures cardiologists perform that might involve anesthesiologists. Mutual knowledge, understanding, and respect are fundamental requirements for integration of cardiology and anesthesia services to optimize patient outcomes.

Approach to and management of the acute stroke patient with atrial fibrillation: a literature review

Stroke remains an increasing worldwide cause of disability and mortality, and it is the second leading cause of death in industrialized countries. Patients with atrial fibrillation form a unique group with increased risk of cardioembolic stroke. Despite the widespread application of the National Institutes of Health stroke scale and guidelines, patients with atrial fibrillation represent a clinically challenging group that deserves a special approach during the acute stroke phase. The mechanism of stroke in these patients is either cardioembolic [especially with an international normalized ratio (INR) < 2.0] or hemorrhagic (especially with INR > 5.0) (Figure 1). Atrial fibrillation with valvular heart disease significantly increases the risk for ischemic stroke. Specifically, patients with mitral stenosis who develop atrial fibrillation increase their risk of cardioembolism by 3 to 7 times. Many patients with atrial fibrillation still develop ischemic or hemorrhagic stroke despite appropriate use of anticoagulation. Prior stroke, transient ischemic attacks, congestive heart failure, hypertension, age > 75, and diabetes mellitus are all well-established risk factors for the development of stroke in patients with atrial fibrillation. The CHADS-2 score is the most widely studied and clinically used method for stratifying patients with nonrheumatic atrial fibrillation. In our review, we present the most recent clinical guidelines and trends for the approach to and management of this patient group.