Trans-aortic Valvular Ejection Fraction for Monitoring Recovery of Patients with Ventricular Systolic Heart Failure.

Durable mechanical circulatory support in the form of left ventricular (LV) assist device (LVAD) therapy is increasingly considered in the context of the recovery of native cardiac function. Progressive improvement in LV function may facilitate LVAD explantation and a resultant reduction in device-related risk. However, ascertaining LV recovery remains a challenge. In this study, we investigated the use of trans-aortic valvular flow rate and trans-LVAD flow rate to assess native LV systolic function using a well-established lumped parameter model of the mechanically assisted LV with pre-existing systolic dysfunction. Trans-aortic valvular ejection fraction (TAVEF) was specifically found to characterize the preload-independent contractility of the LV. It demonstrated excellent sensitivity to simulated pharmacodynamic stress tests and volume infusion tests. TAVEF may prove to be useful in the ascertainment of LV recovery in LVAD-supported LVs with pre-existing LV systolic dysfunction.

Prospective Multicenter Study of Myocardial Recovery Using Left Ventricular Assist Devices (RESTAGE-HF [Remission from Stage D Heart Failure]): Medium-Term and Primary End Point Results.

BACKGROUND: Left ventricular assist device (LVAD) unloading and hemodynamic support in patients with advanced chronic heart failure can result in significant improvement in cardiac function allowing LVAD removal; however, the rate of this is generally considered to be low. This prospective multicenter nonrandomized study (RESTAGE-HF [Remission from Stage D Heart Failure]) investigated whether a protocol of optimized LVAD mechanical unloading, combined with standardized specific pharmacological therapy to induce reverse remodeling and regular testing of underlying myocardial function, could produce a higher incidence of LVAD explantation. METHODS: Forty patients with chronic advanced heart failure from nonischemic cardiomyopathy receiving the Heartmate II LVAD were enrolled from 6 centers. LVAD speed was optimized with an aggressive pharmacological regimen, and regular echocardiograms were performed at reduced LVAD speed (6000 rpm, no net flow) to test underlying myocardial function. The primary end point was the proportion of patients with sufficient improvement of myocardial function to reach criteria for explantation within 18 months with sustained remission from heart failure (freedom from transplant/ventricular assist device/death) at 12 months. RESULTS: Before LVAD, age was 35.1±10.8 years, 67.5% were men, heart failure mean duration was 20.8±20.6 months, 95% required inotropic and 20% temporary mechanical support, left ventricular ejection fraction was 14.5±5.3%, end-diastolic diameter was 7.33±0.89 cm, end-systolic diameter was 6.74±0.88 cm, pulmonary artery saturations were 46.7±9.2%, and pulmonary capillary wedge pressure was 26.2±7.6 mm Hg. Four enrolled patients did not undergo the protocol because of medical complications unrelated to the study procedures. Overall, 40% of all enrolled (16/40) patients achieved the primary end point, P<0.0001, with 50% (18/36) of patients receiving the protocol being explanted within 18 months (pre-explant left ventricular ejection fraction, 57±8%; end-diastolic diameter, 4.81±0.58 cm; end-systolic diameter, 3.53±0.51 cm; pulmonary capillary wedge pressure, 8.1±3.1 mm Hg; pulmonary artery saturations 63.6±6.8% at 6000 rpm). Overall, 19 patients were explanted (19/36, 52.3% of those receiving the protocol). The 15 ongoing explanted patients are now 2.26±0.97 years after explant. After explantation survival free from LVAD or transplantation was 90% at 1-year and 77% at 2 and 3 years. CONCLUSIONS: In this multicenter prospective study, this strategy of LVAD support combined with a standardized pharmacological and cardiac function monitoring protocol resulted in a high rate of LVAD explantation and was feasible and reproducible with explants occurring in all 6 participating sites. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01774656.

Improvement in tricuspid regurgitation following catheter ablation of atrial fibrillation.

INTRODUCTION: Functional tricuspid regurgitation (TR) remains a challenging clinical problem with poor outcomes and few effective treatments. Atrial fibrillation (AF) has been associated with functional TR. We sought to determine whether restoring sinus rhythm through catheter ablation of AF can decrease the degree of TR. METHODS AND RESULTS: A retrospective cohort study of patients undergoing AF ablation between 2011 and 2017 at a single center was conducted. We included patients with at least moderate TR on echocardiogram within the year preceding ablation, who underwent repeat echocardiogram within the year following ablation. Formal quantitative analysis was performed by an experienced research echocardiographer, blinded to arrhythmia outcomes. Arrhythmia-free survival was correlated to the extent of improvement in TR. Thirty-six patients met the inclusion criteria. A baseline echocardiogram was performed 37 ± 68 days before ablation and follow-up echocardiogram 139 ± 112 days following ablation. Patients were 63.7 ± 11.1 years old with a mean CHA2 DS2 -VASc score of 2.7 ± 1.7. The degree of TR improved by at least one grade in 23 patients (64%). TR area decreased from 11.6 ± 3.4 to 7.0 ± 3.5 cm2 (p < .001) following ablation. Freedom from AF postablation was associated with a greater likelihood of improvement in TR by at least one grade (100% vs. 41%, p = .02). CONCLUSIONS: In patients with AF and at least moderate TR, catheter ablation is associated with substantial improvement in TR severity.

Management of ventricular arrhythmias in patients with ventricular assist devices.

PURPOSE OF REVIEW: To summarize the available evidence concerning the occurrence and treatment of ventricular arrhythmias in patients supported with long-term ventricular assist devices (VADs). RECENT FINDINGS: Approximately one-third of left ventricular assist device-supported patients experience significant ventricular arrhythmias, with higher rates in certain patient subsets. Ventricular arrhythmias are associated with both increased mortality and morbidity in VAD-supported patients. Mechanical factors, myocardial fibrosis and alterations in cardiac myocyte physiology because of myocardial unloading are contributors to ventricular arrhythmias in this population. In the absence of definitive trials, current evidence supports implanted cardioverter defibrillators (ICDs) in long-term VAD patients to mitigate the risks associated with ventricular arrhythmias. Though antiarrhythmic therapies have limited efficacy, amelioration of inflow cannula contact with the endocardium and suction events or ablation of specific anatomic origins of ventricular arrhythmias, when present, are also efficacious in VAD-supported hearts. SUMMARY: As the application of long-term VAD support continues to grow, it will be increasingly important to clarify and target the mechanisms contributing to ventricular arrhythmias in this population. Prospective trials assessing the benefits of de-novo ICD placement, ablative strategies and other prophylactic and therapeutic interventions will be increasingly important to further improve the survival and quality of life among VAD-supported patients.