Ventricular assist device using a thoracotomy-based implant technique: Multi-Center Implantation of the HeartMate 3 in Subjects With Heart Failure Using Surgical Techniques Other Than Full Median Sternotomy (HM3 SWIFT).

OBJECTIVES: The HeartMate 3 (Abbott) left ventricular assist device provides substantial improvement in long-term morbidity and mortality in patients with advanced heart failure. The Implantation of the HeartMate 3 in Subjects With Heart Failure Using Surgical Techniques Other Than Full Median Sternotomy study compares thoracotomy-based implantation clinical outcomes with standard median sternotomy. METHODS: We conducted a prospective, multicenter, single-arm study in patients eligible for HeartMate 3 implantation with thoracotomy-based surgical technique (bilateral thoracotomy or partial upper sternotomy with left thoracotomy). The composite primary end point was survival free of disabling stroke (modified Rankin score >3), or reoperation to remove or replace a malfunctioning device, or conversion to median sternotomy at 6-months postimplant (elective transplants were treated as a success). The primary end point (noninferiority, -15% margin) was assessed with >90% power compared with a propensity score-matched cohort (ratio 1:2) derived from the Multi-Center Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 continued access protocol. RESULTS: The study enrolled 102 patients between December 2020 and July 2022 in the thoracotomy-based arm at 23 North American centers. Follow-up concluded in December 2022. In the Implantation of the HeartMate 3 in Subjects With Heart Failure Using Surgical Techniques Other Than Full Median Sternotomy study group, noninferiority criteria was met (absolute between-group difference, -1.2%; Farrington Manning lower 1-sided 95% CI, -9.3%; P < .0025) and event-free survival was not different (85.0% vs 86.2%; hazard ratio, 1.01; 95% CI, 0.58-2.10). Length of stay with thoracotomy-based implant was longer (median, 20 vs 17 days; P = .03). No differences were observed for blood product utilization, adverse events (including right heart failure), functional status, and quality of life between cohorts. CONCLUSIONS: Thoracotomy-based implantation of the HeartMate 3 left ventricular assist device is noninferior to implantation via standard full sternotomy. This study supports thoracotomy-based implantation as an additional standard for surgical implantation of the HeartMate 3 left ventricular assist device.

Increasing Utilization of Extended Criteria Donor Hearts for Transplantation: The OCS Heart EXPAND Trial.

BACKGROUND: Extended criteria donor (ECD) hearts available with donation after brain death (DBD) are underutilized for transplantation due to limitations of cold storage. OBJECTIVES: This study evaluated use of an extracorporeal perfusion system on donor heart utilization and post-transplant outcomes in ECD DBD hearts. METHODS: In this prospective, single-arm, multicenter study, adult heart transplant recipients received ECD hearts using an extracorporeal perfusion system if hearts met study criteria. The primary outcome was a composite of 30-day survival and absence of severe primary graft dysfunction (PGD). Secondary outcomes were donor heart utilization rate, 30-day survival, and incidence of severe PGD. The safety outcome was the mean number of heart graft-related serious adverse events within 30 days. Additional outcomes included survival through 2 years benchmarked to concurrent nonrandomized control subjects. RESULTS: A total of 173 ECD DBD hearts were perfused; 150 (87%) were successfully transplanted; 23 (13%) did not meet study transplantation criteria. At 30 days, 92% of patients had survived and had no severe PGD. The 30-day survival was 97%, and the incidence of severe PGD was 6.7%. The mean number of heart graft-related serious adverse events within 30 days was 0.17 (95% CI: 0.11-0.23). Patient survival was 93%, 89%, and 86% at 6, 12, and 24 months, respectively, and was comparable with concurrent nonrandomized control subjects. CONCLUSIONS: Use of an extracorporeal perfusion system resulted in successfully transplanting 87% of donor hearts with excellent patient survival to 2 years post-transplant and low rates of severe PGD. The ability to safely use ECD DBD hearts could substantially increase the number of heart transplants and expand access to patients in need. (International EXPAND Heart Pivotal Trial [EXPANDHeart]; NCT02323321; Heart EXPAND Continued Access Protocol; NCT03835754).

Incidence, Outcomes, and Opportunity for Left Ventricular Assist Device Weaning for Myocardial Recovery.

BACKGROUND: Myocardial recovery occurs in patients with advanced heart failure on left ventricular assist device (LVAD) support, but there is the premise that it is rare with uncertain results. OBJECTIVES: The goal of this study was to investigate the incidence and consequence of LVAD explant after myocardial recovery. METHODS: Using the United Network for Organ Sharing registry, LVAD implants in the United States between 2005 and 2020 were tracked until death, transplantation, or explant for myocardial recovery. The cohort undergoing explant was followed up for heart failure relapse (defined as relisting followed by delisting due to death, being too ill, or transplantation; or second durable LVAD implant). RESULTS: Of 15,728 LVAD implants, 126 patients underwent explant for recovery, which only occurred in 55 (38%) of 145 implanting centers. The crude cumulative incidence was 0.7% at 2 years, whereas the incidence reached 4.7% among designated centers in the selected young nonischemic cohort. Of 126 explanted patients, 76 (60%) were subsequently delisted for sustained recovery. Heart failure relapsing had a relatively higher hazard in the early phase, with a 30-day incidence of 6% (7 of 126) but tapered following with the freedom rate of 72.5% at 4 years. CONCLUSIONS: In the United States, LVAD explant for myocardial recovery was underutilized, leading to a very low incidence at the national level despite a realistic rate being achieved in designated centers for selected patients. With follow-up extending up to 4 years after explant, more than one-half were successfully removed and stayed off the waitlist, and approximately 70% were free from heart failure relapse events.

Total artificial heart implantation as a bridge to transplantation in the United States.

OBJECTIVES: Although the SynCardia total artificial heart (SynCardia Systems, LLC) was approved for use as a bridge to transplantation in 2004 in the United States, most centers do not adopt the total artificial heart as a standard bridging strategy for patients with biventricular failure. This study was designed to characterize the current use and outcomes of patients placed on total artificial heart support. METHODS: The United Network of Organ Sharing Standard Transplant Research File was queried to identify total artificial heart implantation in the United States between 2005 and 2018. Multivariable Cox regression models were used for risk prediction. RESULTS: A total of 471 patients (mean age, 49 years; standard deviation, 13 years; 88% were male) underwent total artificial heart implantation. Of 161 transplant centers, 11 centers had cumulative volume of 10 or more implants. The 6-month cumulative incidence of mortality on the total artificial heart was 24.6%. The 6-month cumulative incidence of transplant was 49.0%. The 1-year mortality post-transplantation was 20.0%. Cumulative center volume less than 10 implants was predictive of both mortality on the total artificial heart (hazard ratio, 2.2, 95% confidence interval, 1.5-3.1, P < .001) and post-transplant mortality after a total artificial heart bridge (hazard ratio, 1.5, 95% confidence interval, 1.0-2.2, P = .039). CONCLUSIONS: Total artificial heart use is low, but the total artificial heart can be an option for biventricular bridge to transplant with acceptable bridge to transplant and post-transplant survival, especially in higher-volume centers. The observation of inferior outcomes in lower-volume centers raises questions as to whether targeted training, center certifications, and minimum volume requirements could improve outcomes for patients requiring the total artificial heart.

Heparin-induced thrombocytopaenia complicating cardiogenic shock requiring durable mechanical circulatory support: a case report.

Background: Heparin-induced thrombocytopaenia (HIT) is an immune-mediated reaction to heparin therapy that may lead to life-threatening thrombotic events. This disorder complicates intraoperative heparin use during left ventricular assist device (LVAD) implantation. Case summary: A 52-year-old man presented in acute decompensated heart failure. His admission laboratory studies were consistent with cardiogenic shock with a lactate of 6.1 mmol/L (ref range 0.50-1.99 mmol/L). Echocardiogram and CT scan demonstrated severe biventricular dysfunction and a left ventricular ejection fraction of 10%, as well as left upper lobe segmental pulmonary embolism. He was started on inotropes, diuretics, and a heparin infusion. Following heparin initiation, his platelets had decreased by 63% to a nadir of 39 000/µL (ref range 150 000-450 000/µL) and testing confirmed a diagnosis of HIT. His shock state worsened to INTERMACS 1 necessitating escalation of mechanical support. In preparation for HeartMate 3 LVAD implantation, he received 3 cycles of plasmapheresis with one session of IVIG perioperatively, resulting in a 60% reduction in the titre of heparin-dependent platelet antibodies. He underwent successful LVAD implantation including usage of intraoperative heparin, and was discharged home on post-operative Day 17, where he has remained stable on LVAD support. Discussion: Limited data exist on the perioperative management of patients with HIT undergoing LVAD implantation. Heparin is preferred to other antithrombin agents during surgery due to the availability of an immediate reversal agent. Plasmapheresis with IVIG is a potential management option to decrease heparin-dependent platelet antibodies in patients with HIT to allow for successful LVAD implantation.

The use of transesophageal echocardiography to predict surgical complexity scoring system for degenerative mitral valve repair.

BACKGROUND: For severe mitral valve (MV) degenerative disease, repair is recommended. Prediction of repair complexity and referral to high volume centers can increase rates of successful repair. This study sought to demonstrate that TEE is a feasible imaging modality to predict the complexity of surgical MV repair. METHODS: Two hundred TEE examinations of patients who underwent MV repair (2009-2011) were retrospectively reviewed and scored by two cardiac anesthesiologists. TEE scores were compared to surgical complexity scores, which were previously assigned based on published methods. Kappa values were reported for the agreement of TEE and surgical scores. McNemar's tests were used to test the homogeneity of the marginal probabilities of different scoring categories. RESULTS: TEE scores were slightly lower (2[1,3]) than surgical scores (3[1,4]). The agreement was 66% between the scoring methods, with a moderate kappa (.46). Using surgical scores as the gold standard, 70%, 71%, and 46% of simple, intermediate and complex surgical scores, respectively, were correctly scored by TEE. P1, P2, P3, and A2 prolapse were easiest to identify with TEE and had the highest agreement with surgical scoring (P1 agreement 79% with kappa .55, P2 96% [kappa .8], P3 77% [kappa .51], A2 88% [kappa .6]). The lowest agreement between the two scores occurred with A1 prolapse (kappa .05) and posteromedial commissure prolapse (kappa .14). In the presence of significant disagreement, TEE scores were more likely to be of higher complexity than surgical. McNemar's test was significant for prolapse of P1 (p = .005), A1 (p = .025), A2 (p = .041), and the posteromedial commissure (p < .0001). CONCLUSION: TEE-based scoring is feasible for prediction of the complexity of MV surgical repair, thus allowing for preoperative stratification.

Pledgeted versus nonpledgeted sutures in aortic valve replacement: Insights from a prospective multicenter trial.

Objective: The objective of this study was to compare short- and midterm clinical and echocardiographic outcomes according to the use of pledgeted sutures during aortic valve replacement. Methods: Patients with aortic stenosis or regurgitation requiring aortic valve replacement were enrolled in a prospective cohort study to evaluate the safety of a new stented bioprosthesis. Outcomes were analyzed according to the use of pledgets (pledgeted group) or no pledgets (nonpledgeted group). The primary outcome was a composite of thromboembolism, endocarditis, and major paravalvular leak at 5 years of follow-up. Secondary outcomes included multiple clinical endpoints and hemodynamic outcomes. Propensity score matching was performed to adjust for prognostic factors, and subanalyses with small valve sizes (<23 mm) and suturing techniques were performed. Results: The pledgeted group comprised 640 patients (59%), and the nonpledgeted group 442 (41%), with baseline discrepancies in demographic characteristics, comorbidities, and stenosis severity. There were no differences between groups in any outcome. After propensity score matching, the primary outcome occurred in 41 (11.7%) patients in the pledgeted and 36 (9.8%) in the nonpledgeted group (P = .51). The effective orifice area was smaller in the pledgeted group (P = .045), whereas no difference was observed for the mean or peak pressure gradient. Separate subanalyses with small valve sizes and suturing techniques did not show relevant differences. Conclusions: In this large propensity score-matched cohort, comprehensive clinical outcomes were comparable between patients who underwent aortic valve replacement with pledgeted and nonpledgeted sutures up to 5 years of follow-up, but pledgets might lead to a slightly smaller effective orifice area in the long run.

Outcomes of Simultaneous Heart and Kidney Transplantation.

BACKGROUND: Simultaneous heart-kidney transplantation has been increasingly performed in end-stage heart failure patients with concurrent kidney dysfunction despite limited evidence supporting its indications and utility. OBJECTIVES: The purpose of this study was to investigate the effects and utility of simultaneously implanted kidney allografts with various degrees of kidney dysfunction during heart transplantation. METHODS: Using the United Network for Organ Sharing registry, long-term mortality was compared in recipients with kidney dysfunction who underwent heart-kidney transplantation (n = 1,124) vs isolated heart transplantation (n = 12,415) in the United States between 2005 and 2018. In heart-kidney recipients, contralateral kidney recipients were compared for allograft loss. Multivariable Cox regression was used for risk adjustment. RESULTS: Long-term mortality was lower among heart-kidney recipients than among heart-alone recipients when recipients were on dialysis (26.7% vs 38.6% at 5 years; HR: 0.72; 95% CI: 0.58-0.89) or had a glomerular filtration rate (GFR) of <30 mL/min/1.73 m2 (19.3% vs 32.4%; HR: 0.62; 95% CI: 0.46-0.82) and GFR of 30 to 45 mL/min/1.73 m2 (16.2% vs 24.3%; HR: 0.68; 95% CI: 0.48-0.97) but not in GFR of 45 to 60 mL/min/1.73 m2. Interaction analysis showed that the mortality benefit of heart-kidney transplantation continued up to GFR 40 mL/min/1.73 m2. The incidence of kidney allograft loss was higher among heart-kidney recipients than among contralateral kidney recipients (14.7% vs 4.5% at 1 year; HR: 1.7; 95% CI: 1.4-2.1). CONCLUSIONS: Heart-kidney transplantation relative to heart transplantation alone provided superior survival for dialysis-dependent recipients and non-dialysis-dependent recipients up to a GFR of approximately 40 mL/min/1.73 m2 but at the cost of almost twice the risk of kidney allograft loss than contralateral kidney allograft recipients.

Reversal of Total Artificial Heart Mechanical Valve Thrombosis Using Catheter-Directed Thrombolysis.

Total artificial heart is associated with increased incidence of thromboembolism, which can prove to be fatal. The presence of four metallic tilting discs increases the chances of thrombus formation and sudden obstruction of the valve in a closed position resulting in severe hemodynamic collapse. Such a condition is conventionally treated by a surgical approach for device change; however, this procedure is extremely high risk and associated with complications and poor outcomes. We describe two total artificial heart patients with sudden obstruction to the filling of the right side due to fixing of the atrioventricular valve in a closed position due to a thrombus. After a quick diagnosis by rescue transesophageal echocardiography, we successfully treated these patients with catheter-directed thrombolysis with minimal adverse outcomes. We propose a carefully weighed application of this approach in hemodynamically unstable patients too tenuous for a timely surgery and with low risk for bleeding.

Temporary mechanical circulatory support devices: practical considerations for all stakeholders.

Originally intended for life-saving salvage therapy, the use of temporary mechanical circulatory support (MCS) devices has become increasingly widespread in a variety of clinical settings in the contemporary era. Their use as a short-term, prophylactic support vehicle has expanded to include procedures in the catheterization laboratory, electrophysiology suite, operating room and intensive care unit. Accordingly, MCS device design and technology continue to develop at a rapid pace. In this Review, we describe the functionality, indications, management and complications associated with temporary MCS, together with scenario-specific utilization, goal-directed development and bioengineering of future devices. We address various considerations for the use of temporary MCS devices in both prophylactic and rescue scenarios, with input from stakeholders from various cardiovascular specialties, including interventional and heart failure cardiology, electrophysiology, cardiothoracic anaesthesiology, critical care and cardiac surgery.

A bridge-to-bridge approach to heart transplantation using extracorporeal membrane oxygenation and total artificial heart.

BACKGROUND: This study aims to describe the outcomes after heart transplantation using a bridge-to-bridge strategy with a sequence of extracorporeal membrane oxygenation (ECMO) support followed by temporary total artificial heart implantation (TAH-t). METHODS: A retrospective, multicenter analysis of 54 patients who underwent TAH-t implantation following an ECMO for cardiogenic shock was performed (ECMO-TAH-t group). A control group of 163 patients who underwent TAH-t implantation as a direct bridge to transplantation (TAH-t group) was used to assess this strategy's impact on outcomes. RESULTS: Fifty-four patients, averaging 47 ± 13 year old, underwent implantation of a TAH-t after 5.3 ± 3.4 days of ECMO perfusion for cardiogenic shock. In the ECMO-TAH-t group, 20 patients (20/54%; 37%) died after TAH-t implantation and 57 patients (57/163%; 35%) died in the TAH-t group (Gray test; P = .49). The top 3 causes of death of patients on TAH-t support were multisystem organ failure (40%), sepsis (20%), and neurologic events (20%). Overall, 32 patients (32/54%; 59%) underwent heart transplantation in the ECMO-TAH-t group compared with 106 patients (106/163%, 65%) in the TAH-t group (P = .44). No significant difference in survival was observed at 6 months, 1 year, and 3 years after heart transplant (ECMO-TAH-t group: 94%, 87%, and 80% vs 87%, 83%, and 76% in the TAH-t group, respectively). Deterioration of liver function (bilirubin, aspartate transaminase, and alanine aminotransferase levels on TAH-t) was associated with increased mortality before heart transplant in both groups. CONCLUSIONS: Sequential bridging from ECMO to TAH-t followed by heart transplantation is a viable option for a group of highly selected patients.

Association of Donor Brain Death Due to Stroke With Prognosis After Heart Transplantation.

BACKGROUND: The proximate cause of donor brain death is not considered a conventional risk factor in modern heart transplantation. OBJECTIVES: This study aimed to investigate the effect of the cause of donor brain death on recipients. METHODS: Using the United Network for Organ Sharing registry, long-term mortality and allograft failure were compared in recipients who underwent heart transplantation in the United States from 2005 through 2018 between allograft recipients from donors with stroke as the cause of brain death (n = 3,761) vs nonstroke causes (n = 14,677). Inverse probability weighting was used for risk adjustment. Interactions were investigated between the cause of brain death and other conventional donor risk factors for recipient mortality. RESULTS: There was an interaction between the cause of brain death and donor age (Pinteraction = 0.008). When allografts were procured from donors aged 40 years or younger, stroke as the cause of brain death was associated with an increased risk of mortality (23% vs 19% at 5 years; HR: 1.17; 95% CI: 1.02-1.35) and allograft failure (HR: 1.30; 95% CI: 1.04-1.63). When donors were older than 40 years, the cause of brain death was not associated with outcomes. CONCLUSIONS: As the cause of donor brain death, stroke had a substantially different effect on recipient and allograft survival depending on donor age. In the case of younger donor ages, stroke was associated with higher recipient mortality and allograft failure than other causes of brain death. The strength of this association decreased with increasing donor age such that the increased hazard was no longer present in donors older than approximately 40 years.

Outcomes after heart transplantation and total artificial heart implantation: A multicenter study.

BACKGROUND: We sought to assess the outcomes after heart transplantation (HT) of patients supported with a temporary total artificial heart (t-TAH) as a bridge to transplantation in high-volume centers. METHODS: A retrospective analysis of 217 consecutive patients who underwent t-TAH (SynCardia Systems, Tucson, Arizona) implantation between January 2014 and May 2019 in 6 high-volume North American centers was performed. End points included survival and adverse events after t-TAH and HT. RESULTS: The mean age of patients was 49 ± 12 years, and heart failure etiologies were non-ischemic dilated cardiomyopathy (36%), ischemic (25%), restrictive (12%), and cardiac graft failure (9%). A total of 101 (48%) patients had Interagency Registry for Mechanically Assisted Circulatory Support patient profile 1, and 65 (31%) had Interagency Registry for Mechanically Assisted Circulatory Support patient profile 2. At the end of the study period, 138 of 217 (63.5%) patients had undergone HT, and 75 (34.5%) patients died before HT. The mean time between t-TAH implantation and HT averaged 181 ± 179 days (range: 0-849) and the mean follow-up after HT was 35 ± 25 months. The overall survival in the entire cohort was 75%, 64%, and 58% at 1, 2, and 5 years, respectively. Post-transplant survival was 88%, 84%, 79%, and 74% at 6 months, 1 year, 2 years, and 5 years, respectively. Among the 32 patients (23%) who died after HT, the main causes of death were chronic allograft vasculopathy (25%), multiorgan failure (21.8%), sepsis (15.6%), and stroke (9%). CONCLUSION: In this multicenter study, almost two thirds of patients implanted with a t-TAH could be transplanted. The overall and post-transplantation survival after t-TAH was satisfactory in these critically ill patients.