Incidence and Outcomes of Postoperative Atrial Fibrillation After Left Ventricular Assist Device

Atrial fibrillation increases thrombogenicity of LVAD therapy

BACKGROUND

This study investigates the hypothesis that presence of atrial fibrillation (AF) in LVAD patients increases thrombogenicity in the left ventricle (LV) and exacerbates stroke risk.

METHODS

Using an anatomical LV model implanted with an LVAD inflow cannula, we analyze thrombogenic risk and blood flow patterns in either AF or sinus rhythm (SR) using unsteady computational fluid dynamics (CFD). To analyze platelet activation and thrombogenesis in the LV, hundreds of thousands of platelets are individually tracked to quantify platelet residence time (RT) and shear stress accumulation history (SH).

RESULTS

The irregular and chaotic mitral inflow associated with AF results in markedly different intraventricular flow patterns, with profoundly negative impact on blood flow-induced stimuli experienced by platelets as they traverse the LV. Twice as many platelets accumulated very high SH in the LVAD + AF case, resulting in a 36% increase in thrombogenic potential score, relative to the LVAD + SR case.

CONCLUSIONS

This supports the hypothesis that AF results in unfavorable blood flow patterns in the LV adding to an increased stroke risk for LVAD + AF patients. Quantification of thrombogenic risk associated with AF for LVAD patients may help guide clinical decision-making on interventions to mitigate the increased risk of thromboembolic events.

Considerations for Left Atrial Appendage Occlusion During Cardiac Surgery

Atrial fibrillation is associated with an increased risk of stroke secondary to thrombus formation in the left atrial appendage. Left atrial appendage occlusion (LAAO) is an effective method of reducing the risk of stroke in patients with atrial fibrillation. Although LAAO does not remove the requirement for anticoagulation, it reduces the risk of stroke when compared to anticoagulation alone. We critically analyze the data on LAAO in cardiac surgery. We also discuss the methods of LAAO, the risks of LAAO, and patient populations that could benefit from LAAO. We discuss high-level evidence that LAAO at the time of cardiac surgery reduces the risk of stroke in patients with a history of atrial fibrillation. In patients without a history of atrial fibrillation undergoing cardiac surgery, we suggest that LAAO should be considered in select patients at high risk of atrial fibrillation and stroke, when technically feasible.

Safety and Efficacy of Prophylactic Amiodarone After Left Ventricular Assist Device

The prophylactic use of amiodarone to reduce the incidence of postoperative arrhythmias is effective for patients undergoing general cardiac surgeries; however, no data exists for the use of prophylactic amiodarone to prevent postoperative arrhythmias after CF-LVAD. This single-center, retrospective analysis compared patients with CF-LVADs placed between April 2014 and June 2020 who received prophylactic postoperative amiodarone to those who did not. Based on institution practice at the respective times, patients with a CF-LVAD placed between April 2014 and June 2018 were included in the group receiving postoperative amiodarone arrhythmia prophylaxis and patients with a CF-LVAD placed July 2018 to June 2020 were included in the group not receiving arrhythmia prophylaxis. The primary outcome was the incidence of first occurring atrial or ventricular arrhythmia from CF-LVAD placement to 21 days or hospital discharge. Sixty patients received amiodarone for arrhythmia prophylaxis and 27 patients did not receive prophylaxis. The primary outcome occurred in 40% of the prophylaxis group and 66.7% in the no prophylaxis group (RR, 0.60; 95% CI, 0.40-0.90; p = 0.038). In patients receiving CF-LVADs, the use of prophylactic amiodarone was associated with a reduction in the incidence of postoperative arrhythmias, which was driven primarily by a reduction in postoperative atrial arrhythmias, without significantly increasing the rate of amiodarone-related adverse events.

Left atrial appendage occlusion in ventricular assist device patients to decrease thromboembolic events: A computer simulation study

Atrial fibrillation (AF) is a common comorbidity in left ventricular assist device (LVAD) patients and has been identified as a risk factor for thromboembolic stroke. Blood stagnation within the left atrial appendage (LAA) is considered a possible major source of thrombosis and clinical studies have shown reduced thromboembolic risk after LAA occlusion (LAAO). Therefore, this study aims to investigate the effect of LAAO on thrombosis-related parameters using patient-specific simulations. Left ventricular and left atrial geometries of an LVAD patient were obtained from computed tomography and combined with hemodynamic data with either sinus rhythm (SR) or AF generated by a lumped parameter model. In four simulations applying contractile walls, stagnation volume and blood residence times were evaluated with or without AF and with or without LAAO. Reduced atrial contraction in AF resulted in unfavorable flow dynamics within the left atrium. The average atrial velocity was lower for the AF simulation when compared to SR, resulting in a 55% increase in the atrial stagnation volume (from 4.2 to 6.5 cm³). Moreover, blood remained in the LAA for more than 8 cardiac cycles. After LAAO the atrial stagnation decreased from 4.2 to 1.4 cm³ for SR and from 6.5 to 2.3 cm³ for the AF simulation. A significant stagnation volume was found in the LAA for both SR and AF, with larger values occurring with AF. These regions are known as potential sources for thrombus formation and can be diminished by LAAO. This significantly improved the thrombus-related flow parameters and may also lower the risk of thromboembolic events from the appendage.

Trends and Outcomes of Left Ventricular Assist Device Therapy: JACC Focus Seminar

As the prevalence of advanced heart failure continues to rise, treatment strategies for select patients include heart transplantation or durable left ventricular assist device (LVAD) support, both of which improve quality of life and extend survival. Recently, the HeartMate 3 has been incorporated into clinical practice, the United Network for Organ Sharing donor heart allocation system was revised, and the management of LVAD-related complications has evolved. Contemporary LVAD recipients have greater preoperative illness severity, but survival is higher and adverse event rates are lower compared with prior eras. This is driven by advances in device design, patient selection, surgical techniques, and long-term management. However, bleeding, infection, neurologic events, and right ventricular failure continue to limit broader implementation of LVAD support. Ongoing efforts to optimize management of patients implanted with current devices and parallel development of next-generation devices are likely to further improve outcomes for patients with advanced heart failure.

Catheter ablation for atrial fibrillation in left ventricular assist device: A case report

INTRODUCTION

Mechanical circulatory support such as the left ventricular assist device (LVAD) has become widely implemented in the treatment of end-stage heart failure, whether as bridge-to-transplant or as destination therapy. The hemodynamic effects of arrhythmia on LVADs and its management are significant in determining the long-term outcome of these patients. Both atrial arrhythmia and ventricular arrhythmia are commonly seen after implantation of the device. There are no strict guidelines, however, on the need for intensive management of arrhythmias in LVAD. In this case report, we present a patient with new onset atrial fibrillation after LVAD implantation which leads to acute decompensating heart failure. The patient was treated with catheter ablation. The intervention demonstrated positive outcomes for this patient.

PATIENT CONCERNS

The patient was a Korean male, who presented with dyspnea, fatigue and generalized edema after persistent atrial fibrillation precipitated by implantation of the left ventricular assist device.

DIAGNOSIS

The patient was diagnosed with acute decompensating heart failure that was aggravated by recurrent atrial arrhythmia.

INTERVENTION

We attempted to relieve symptoms of right ventricular dysfunction by method of strict rhythm control in this patient. The patient underwent radiofrequency catheter ablation for recurrent atrial fibrillation.

OUTCOME

The patient showed improved clinical symptoms, BNP levels, and echocardiogram parameters immediately after the procedure as well as during long term outpatient follow up.

CONCLUSION

In this case report, we present the first successful case in Korea of atrial fibrillation in LVAD treated with catheter ablation. This case suggests setting catheter ablation as a routine first-line treatment for atrial arrhythmia in LVAD patients, especially when the arrhythmia predisposes the patient at risk for decompensating heart failure.

Atrial arrhythmias in patients with left ventricular assist devices

PURPOSE OF REVIEW

Atrial arrhythmias commonly occur in patients with advanced heart failure with reduced ejection fraction (HFrEF) who require left ventricular assist devices (LVADs) implantation. This review summarizes the current literature regarding the incidence, prevalence, and predictors of atrial arrhythmias in LVAD patients and its impact on the clinical outcomes. Moreover, we review the mechanisms and management strategies of atrial arrhythmias in this population.

RECENT FINDINGS

Atrial arrhythmias including atrial fibrillation, atrial flutter, and atrial tachycardia are highly prevalent in patients with advanced HFrEF before or after the LVAD implantation. Atrial arrhythmias have a significant impact on overall clinical outcome including survival, heart failure hospitalization, quality of life, thromboembolic events and resource utilization. Atrial fibrillation and other atrial arrhythmias frequently coexist in this population. In patients with atrial arrhythmias and LVAD, anticoagulation and cardiovascular implantable electronic devices should be closely monitored and managed to prevent thromboembolic events or inappropriate shocks. Rhythm and rate control strategies are comparable regarding overall clinical outcomes in this population. LVADs induce favorable atrial remodeling in patients with HFrEF.

SUMMARY

Atrial arrhythmias are highly common in LVAD patients and have significant impact on overall clinical outcomes. Further studies are needed to determine optimal management and prevention of atrial arrhythmias in LVAD population.

Impact of preoperative atrial fibrillation in patients with left ventricular assist device: A systematic review and meta-analysis

Atrial fibrillation (AF) is a common finding in patients evaluated for left ventricular assist device (LVAD). There is conflicting data regarding the mortality risk as well as the thromboembolic risk in patients with preoperative AF who undergo LVAD implantation. We examined these risks by performing a meta-analysis. We performed a literature search of Pubmed, EMBASE, SCOPUS, and Cochrane from inception to February 2018. The eligible studies were used to compare mortality rate and thromboembolic risk between AF and Non-AF (NAF) groups after LVAD implantation. We obtained 391 articles from our search strategy. Seven retrospective studies were included and accounted for 5823 LVAD patients (AF 1589; NAF 4234). The median follow-up duration ranged from 7-24 months. The pooled analysis revealed a significantly increased risk of mortality in preoperative AF patients who underwent LVAD operation compared to those with NAF (Risk Ratio [RR] 1.16, 95% CI 1.05-1.28, I2 = 0%). Five studies reported thromboembolism events involving 1359 preoperative AF and 3893 NAF patients. The pooled analysis did not show a statistically significant association between risk of thromboembolic event and preoperative AF (Risk Ratio [RR] 1.08, 95% CI 0.86-1.36, I2 = 76.2%). Our study shows that preoperative AF may be associated with a higher mortality rate. This study is limited by the fact that the data are pooled from retrospective studies. Further prospective studies are warranted in order to validate these results.

Left ventricular assist devices and their complications: A review for emergency clinicians

INTRODUCTION

End stage heart failure is associated with high mortality. However, recent developments such as the ventricular assist device (VAD) have improved patient outcomes, with left ventricular assist devices (LVAD) most commonly implanted.

OBJECTIVE

This narrative review evaluates LVAD epidemiology, indications, normal function and components, and the assessment and management of complications in the emergency department (ED).

DISCUSSION

The LVAD is a life-saving device in patients with severe heart failure. While first generation devices provided pulsatile flow, current LVAD devices produce continuous flow. Normal components include the pump, inflow and outflow cannulas, driveline, and external controller. Complications related to the LVAD can be divided into those that are LVAD-specific and LVAD-associated, and many of these complications can result in severe patient morbidity and mortality. LVAD-specific complications include device malfunction/failure, pump thrombosis, and suction event, while LVAD-associated complications include bleeding, cerebrovascular event, infection, right ventricular failure, dysrhythmia, and aortic regurgitation. Assessment of LVAD function, patient perfusion, and mean arterial pressure is needed upon presentation. Electrocardiogram and bedside ultrasound are key evaluations in the ED. LVAD evaluation and management require a team-based approach, and consultation with the LVAD specialist is recommended.

CONCLUSION

Emergency clinician knowledge of LVAD function, components, and complications is integral in optimizing care of these patients.

Left Ventricular Assist Device Management in the Emergency Department

The prevalence of patients living with a left ventricular assist device (LVAD) is rapidly increasing due to improvements in pump technology, limiting the adverse event profile, and to expanding device indications. To date, over 22,000 patients have been implanted with LVADs either as destination therapy or as a bridge to transplant. It is critical for emergency physicians to be knowledgeable of current ventricular assist devices (VAD), and to be able to troubleshoot associated complications and optimally treat patients with emergent pathology. Special consideration must be taken when managing patients with VADs including device inspection, alarm interpretation, and blood pressure measurement. The emergency physician should be prepared to evaluate these patients for cerebral vascular accidents, gastrointestinal bleeds, pump failure or thrombosis, right ventricular failure, and VAD driveline infections. Early communication with the VAD team and appropriate consultants is essential for emergent care for patients with VADs.