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).

Right Ventricular Assist Device Placement During Left Ventricular Assist Device Implantation Is Associated With Improved Survival

Right ventricular failure (RVF) is a significant cause of mortality in patients undergoing left ventricular assist device (LVAD) implantation. Although right ventricular assist devices (RVADs) can treat RVF in the perioperative LVAD period, liberal employment before RVF is not well established. We therefore compared the survival outcomes between proactive RVAD placement at the time of LVAD implantation with a bailout strategy in patients with RVF. Retrospectively, 75 adult patients who underwent durable LVAD implantation at our institution and had an RVAD placed proactively before LVAD implantation or as a bailout strategy postoperatively due to hemodynamically unstable RVF were evaluated. Patients treated with a proactive RVAD strategy had lower Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) and a higher proportion of these required temporary mechanical circulatory support (MCS) preoperatively. Preoperative hemodynamic profiling showed a low pulmonary artery pulsatility index (PAPi) score of 1.8 ± 1.4 and 1.6 ± 0.94 (p = 0.42) in the bailout RVAD and proactive RVAD groups, respectively. Survival at 3, 6, and 12 months post-LVAD implantation was statistically significantly higher in patients who received a proactive RVAD. Thus, proactive RVAD implantation is associated with short- and medium-term survival benefits compared to a bailout strategy in RVF patients undergoing LVAD placement.

Transplantation Outcomes with Donor Hearts after Circulatory Death

BACKGROUND

Data showing the efficacy and safety of the transplantation of hearts obtained from donors after circulatory death as compared with hearts obtained from donors after brain death are limited.

METHODS

We conducted a randomized, noninferiority trial in which adult candidates for heart transplantation were assigned in a 3:1 ratio to receive a heart after the circulatory death of the donor or a heart from a donor after brain death if that heart was available first (circulatory-death group) or to receive only a heart that had been preserved with the use of traditional cold storage after the brain death of the donor (brain-death group). The primary end point was the risk-adjusted survival at 6 months in the as-treated circulatory-death group as compared with the brain-death group. The primary safety end point was serious adverse events associated with the heart graft at 30 days after transplantation.

RESULTS

A total of 180 patients underwent transplantation; 90 (assigned to the circulatory-death group) received a heart donated after circulatory death and 90 (regardless of group assignment) received a heart donated after brain death. A total of 166 transplant recipients were included in the as-treated primary analysis (80 who received a heart from a circulatory-death donor and 86 who received a heart from a brain-death donor). The risk-adjusted 6-month survival in the as-treated population was 94% (95% confidence interval [CI], 88 to 99) among recipients of a heart from a circulatory-death donor, as compared with 90% (95% CI, 84 to 97) among recipients of a heart from a brain-death donor (least-squares mean difference, -3 percentage points; 90% CI, -10 to 3; P<0.001 for noninferiority [margin, 20 percentage points]). There were no substantial between-group differences in the mean per-patient number of serious adverse events associated with the heart graft at 30 days after transplantation.

CONCLUSIONS

In this trial, risk-adjusted survival at 6 months after transplantation with a donor heart that had been reanimated and assessed with the use of extracorporeal nonischemic perfusion after circulatory death was not inferior to that after standard-care transplantation with a donor heart that had been preserved with the use of cold storage after brain death. (Funded by TransMedics; ClinicalTrials.gov number, NCT03831048.).

Left Ventricular Assist Devices: A Primer For the General Cardiologist

Durable implantable left ventricular assist devices (LVADs) have been shown to improve survival and quality of life for patients with stage D heart failure. Even though LVADs remain underused overall, the number of patients with heart failure supported with LVADs is steadily increasing. Therefore, general cardiologists will increasingly encounter these patients. In this review, we provide an overview of the field of durable LVADs. We discuss which patients should be referred for consideration of advanced heart failure therapies. We summarize the basic principles of LVAD care, including medical and surgical considerations. We also discuss the common complications associated with LVAD therapy, including bleeding, infections, thrombotic issues, and neurologic events. Our goal is to provide a primer for the general cardiologist in the recognition of patients who could benefit from LVADs and in the principles of managing patients with LVAD. Our hope is to "demystify" LVADs for the general cardiologist.

Endovascular management of left ventricular assist device outflow graft stenosis

Stenosis of left ventricular assist devices has traditionally required open operative management with device revision or replacement; however, endovascular therapy is emerging as an alternative to open surgery. Limited by the rarity of this approach, consensus is lacking regarding the optimal technique. In this publication, we present a case report of outflow graft stenosis managed with endovascular treatment and discuss technical considerations including preoperative planning, stent selection, and procedural adjuncts.

Aortic Size and Clinical Care Pathways Before Type A Aortic Dissection

Patients with aortic enlargement are recommended to undergo serial imaging and clinical follow-up until they reach surgical thresholds. This study aimed to identify aortic diameter and care of patients with aortic imaging before aortic dissection (AD). In a retrospective cohort of AD patients, we evaluated previous imaging results in addition to ordering providers and indications. Imaging was stratified as >1 or <1 year: 62 patients (53% men) had aortic imaging before AD (most recent test: 82% echo, 11% computed tomography, 6% magnetic resonance imaging). Imaging was ordered most frequently by primary care physicians (35%) and cardiologists (39%). The most frequent imaging indications were arrhythmia (11%), dyspnea (10%), before or after aortic valve surgery (8%), chest pain (6%), and aneurysm surveillance in 13%. Of all patients, 94% had aortic diameters below the surgical threshold before the AD. Imaging was performed <1 year before AD in 47% and aortic size was 4.4 ± 0.8 cm in ascending aorta and 4.0 ± 0.8 cm in sinus. In patients whose most recent imaging was >1 year before AD (1,317 ± 1,017 days), the mean ascending aortic diameter was 4.2 ± 0.4 cm. In conclusion, in a series of patients with aortic imaging before AD, the aortic size was far short of surgical thresholds in 94% of the group. In >50%, imaging was last performed >1 year before dissection.

Impact of a multidisciplinary acute aortic dissection program: Improved outcomes with a comprehensive initial surgical repair strategy

OBJECTIVE

As part of a multidisciplinary aortic dissection (AD) program, a more comprehensive repair strategy for patients with acute type A aortic dissection (ATAAD) and frequent endografting for suitable patients with type B aortic dissection (ATBAD) was adopted in 2015. The aim of this study was to evaluate the impact of these changes.

METHODS

This study is a retrospective review of a prospective database containing all patients treated for acute AD between 2003 and 2020. Patients were grouped based on differing repair strategies (pre 2015 vs post 2015). Clinical characteristics, procedural details, and survival data were analyzed.

RESULTS

During this time, 323 patients (210 pre, 113 post) were treated for acute AD at our institution. There were 221 patients with ATAAD (149 pre, 72 post) and 102 patients with ATBAD (61 pre, 41 post). The majority (60%) were males, with a mean age of 65.9 ± 15.2 years. There were no differences in cardiovascular risk factors or demographics between the groups. After 2015, fewer patients with ATAAD underwent medical management alone (15% pre vs 4% post; P = .014), and most that underwent surgical intervention had a total arch or aggressive hemiarch repair (27% pre vs 78% post; P < .001). Seventy-four patients (73%) with ATBAD were treated medically, whereas 28 underwent medical management and endografting (23% pre, 34% post; P = .214). For all patients with AD, 30-day mortality was significantly improved (26% pre vs 10% post; P < .001) especially among patients who underwent ATAAD surgery (23% pre vs 9% post; P = .018). Three-year Kaplan-Meier survival estimates showed survival improvement among patients with ATAAD (Log rank P-value = .019); however, this improvement does not extend to type B dissections or the overall cohort. A survival analysis landmarked to 30 days after initial presentation showed no statistical difference in survival from 30 days to 3 years post-presentation.

CONCLUSIONS

A more comprehensive repair strategy in the management of patients with acute AD resulted in improved overall patient outcomes and significantly decreased 30-day mortality, even though more complex repairs were performed. The long-term impact of the changes made to our program remains to be evaluated.

Outcomes of percutaneous and surgical pulmonary valve implantation

BACKGROUND

The objective of this study is to describe the recent trends and in-hospital outcomes with percutaneous pulmonic valve implantation (PPVI) and surgical pulmonic valve implantation (SPVR) in adult hospitals in the US after the availability of both the Melody valve (Medtronic Inc., Minneapolis, Minnesota) and the Sapien XT valve (Edwards Lifesciences, Irvine, CA).

METHODS

We queried the National Inpatient Sample database (NIS) from January 2016 to December 2017 to identify hospitalizations for PPVI and SPVR.

RESULTS

We identified 5455 weighted discharges with PPVI and SPVR (PPVI=1140, SPVR=4305). PPVI procedures had increased in number over 2016 and 2017 (115 procedure at the first quarter of 2016, 195 procedures in the final quarter of 2017, P-trend=0.086), while SPVR volume remained constant. The incidence of in-hospital mortality was low with both procedures (SPRV: 1.6% vs. PPVI: 0.9%, p=0.071). SPVR had worse in-hospital outcomes, was associated with a longer length of stay [5 days vs. 1 day, p<0.001], and comparable cost of index hospitalization [$51,657 vs. $51,193] compared with PPVI.

CONCLUSION

After approval of the Sapien valve for commercial use in 2016, PPVI procedures have increased in frequency. PPVI is associated with lower procedural complications than SPVR, however, both carry a low risk of mortality. Despite the higher cost of the valves and delivery systems, PPVI is associated with a slightly lower cost of index hospitalization compared with SPVR, likely due to the higher in-hospital complications and LOS of the latter.

Multidisciplinary shock team is associated with improved outcomes in patients undergoing ECPR

OBJECTIVES

Veno-arterial extracorporeal membrane oxygenation (VA ECMO) has been increasingly used in cardiopulmonary resuscitation (ECPR) in select patients. Few centers have published their experience or outcomes with ECPR. The aim of our study was to evaluate outcomes of adult patients in cardiac arrest placed on VA ECMO in the catheterization laboratory.

METHODS

We performed a retrospective analysis of adult patients in refractory cardiac arrest who underwent ECPR at the Minneapolis Heart Institute (MHI) at Abbott Northwestern Hospital from January 2012 to December 2017. Relevant data were obtained from electronic medical records, including arrest to ECMO flow time, total ECMO support time, and outcomes.

RESULTS

Twenty-six adult patients underwent ECPR at the study site during the defined time period. Seven patients (27%) sustained cardiac arrest out of hospital, 19 patients arrested in-hospital with eight of those occurring in the catheterization laboratory. Seventeen (65%) patients had initial rhythm of ventricular fibrillation or tachycardia (VF/VT). All patients underwent mechanical CPR with LUCAS device. Overall 30 day and 6 month survival was 69%. Median time from arrest to ECMO flow was 46 mins (21,68) vs 61 mins (36,71) in survivors and non-survivors, respectively. Sixteen of 18 survivors discharged with a CPC score of 1 or 2.

CONCLUSIONS

We demonstrate that adult patients in cardiac arrest initiated on VA ECMO in the cardiac catheterization laboratory and cared for by a multidisciplinary shock team in the critical care unit have superior long-term survival and functionally favorable neurologic recovery when compared to current literature.

Impact of the Commercial Introduction of Transcatheter Mitral Valve Repair on Mitral Surgical Practice

Background

There has been uncertainty regarding the effect of transcatheter mitral valve repair (TMVr) with MitraClip on cardiac surgical practice. Our aim was to examine the impact of the commercial introduction of TMVr to a comprehensive mitral program.

Methods and Results

We evaluated 875 patients (aged 69±14 years; 58% men) who underwent transcatheter or mitral surgical procedures over a 6‐year period at our institution. Main outcomes were changes in surgical procedural volume after TMVr introduction and short‐term mortality for surgical and TMVr procedures. The numbers of patients treated with MitraClip, isolated mitral repair, and any mitral surgery were 249, 292, and 626 patients, respectively. Compared with surgery, patients with MitraClip were older (aged 82±8 versus 64±12 years; P<0.001) and had more severe morbidity. Following the introduction of MitraClip, surgical volumes steadily increased to a rate of 10 (95% CI, 3–7) procedures per year for isolated mitral procedures and 17 (95% CI, 13–20) procedures per year for all mitral surgeries. Both MitraClip and surgical volumes increased at the same rate (P=0.42). In‐hospital mortality was 3.2% for MitraClip and 2.1% for all mitral surgeries (P=0.33). At 30 days, survival free of all mortality (P=0.17) and freedom from heart failure rehospitalization (P=0.75) were similar for transcatheter and surgical procedures.

Conclusions

The commercial introduction of TMVr may be associated with growth in cardiac surgery, without detracting from other therapies, and favorable clinical outcomes for all treated mitral regurgitation patients. These findings demonstrate the potential benefits of complementary therapies in the treatment of patients with mitral regurgitation.

Outcomes of Extracorporeal Membrane Oxygenation Support for Complex High-Risk Elective Percutaneous Coronary Interventions: A Single-Center Experience and Review of the Literature

OBJECTIVES

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is most commonly used in patients with cardiac arrest and cardiogenic shock. There are limited data on the use of VA-ECMO for elective, high-risk percutaneous coronary intervention (PCI). We examined the in-hospital and mid-term clinical outcomes in patients undergoing complex, high-risk PCI with VA-ECMO support.

METHODS

. We conducted a retrospective review of ECMO-supported elective high-risk PCIs performed at our institution between May 2012 and May 2017. The electronic medical records and angiograms were individually reviewed. We assessed the in-hospital and mid-term major adverse cardiovascular and cerebrovascular event (MACCE) rates, and reviewed bleeding and vascular complications.

RESULTS

Five patients underwent elective high-risk PCI with ECMO support. Mean age was 66.8 ± 8.6 years and all patients were men. The mean ejection fraction was 26.6 ± 18.0%. Most procedures were unprotected left main PCIs. All PCIs were successful; 1 patient required femoral artery surgical repair. The mean hospital stay post procedure was 6.4 ± 2.0 days. ECMO was successfully weaned in all cases, and the duration of ECMO was <24 hours in 4 cases. There was no occurrence of in-hospital and 1-year MACCE.

CONCLUSION

ECMO can be successfully used for hemodynamic support during elective high-risk PCI.