Use of left atrial appendage as an autologous tissue source for epicardial micrograft transplantation during LVAD implantation

To prevent death from atrial fibrillation, a cardiac disease which kills by producing emboli. Atrial fibrillation causes about 25% of strokes and increases stroke rate by five times. Over 90% of these embolic strokes are from clots originating in the left atrial appendage. This study addresses the surgical feasibility of removing the appendage to prevent future deaths in two subcategories of patients. (1) Prophylactic removal during open-heart surgery to study its safety. Theoretically, as these patients age and some develop atrial fibrillation, protection from embolic strokes would already be present. (2) Therapeutic removal in chronic atrial fibrillation patients by means of a thorascopic approach. Its technical feasibility is demonstrated. Its actual stroke prevention potential awaits large studies. Appendectomy has been evaluated three ways. (1) Experimentally, thorascopic appendage removal was performed on 20 goats with endoscopic approach. Late studies showed a cleanly healed atrial closure after stapling, and no puckering of tissue as seen with the purse-string approach. (2) Safety of human appendectomy was demonstrated in 437 patients (1995-1997). Routine appendectomy was performed during open-heart surgery. Forty-three appendages were stapled, 391 sutured off. (3) Thorascopic appendectomy in seven patients with chronic atrial fibrillation has been successfully accomplished as an isolated surgical procedure. Stapling or suture closure provides a much cleaner, non-puckered suture line than a purse string. In prophylactic removal, no acute bleeding occurred. No late problems have been identified. Endoscopic removal of the appendage has been successful in seven atrial fibrillation patients. The left atrial appendage is a lethal source of emboli in atrial fibrillation patients. As patients age and often develop atrial fibrillation, prophylactic appendage removal whenever the chest is open is suggested as a method to prevent future strokes. In chronic atrial fibrillation patients, appendectomy can be done with a mini-thorascopic approach. Further studies are planned to demonstrate the effectiveness of appendectomy in preventing strokes in the chronic fibrillating patients.

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 non-randomized study (RESTAGE-HF) 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 non-ischemic 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 (6000rpm, no net flow) to test underlying myocardial function. The primary endpoint was the proportion of patients with sufficient improvement of myocardial function to reach criteria for explantation within 18 months with sustained remission from HF (freedom from transplant/VAD/death) at 12 months. Results: Prior to LVAD age was 35.1±10.8 years, 67.5% were male, heart failure mean duration was 20.8±20.6 months, 95% required inotropic and 20% temporary mechanical support, left ventricular ejection fraction (LVEF) was 14.5±5.3%, end-diastolic diameter (LVEDD) 7.33±0.89cm, end-systolic diameter (LVESD) 6.74±0.88cm, PA saturations were 46.7±9.2% and pulmonary capillary wedge pressure (PCWP) was 26.2±7.6mmHg. Four enrolled patients did not undergo the protocol due to medical complications unrelated to the study procedures. Overall 40% of all enrolled (16/40) patients achieved the primary endpoint, p<0.0001, with 50% (18/36) of patients receiving the protocol being explanted within 18 months (pre-explant LVEF 57±8%; LVEDD 4.81±0.58cm; LVESD 3.53±0.51cm; PCWP 8.1±3.1mmHg; PA sats 63.6±6.8% at 6000rpm). Overall 19 patients were explanted (19/36, 52.3% of those receiving the protocol). The fifteen ongoing explanted patients are now 2.26±0.97years post explant. Post-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 pharmacologic and cardiac function monitoring protocol resulted in a high rate of LVAD explantation and was feasible and reproducible with explants occurred in all six participating sites.

Time course and predictors of myocardial recovery on contemporary left ventricular assist device support are poorly defined because of limited number of recovery patients at any implanting center. This study sought to investigate myocardial recovery using multicenter data from the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS).