Ex vivo lung perfusion in donation after circulatory death: A post hoc analysis of the Normothermic Ex Vivo Lung Perfusion as an Assessment of Extended/Marginal Donors Lungs trial.

OBJECTIVE: Donation after circulatory death (DCD) donors offer the ability to expand the lung donor pool and ex vivo lung perfusion (EVLP) further contributes to this ability by allowing for additional evaluation and resuscitation of these extended criteria donors. We sought to determine the outcomes of recipients receiving organs from DCD EVLP donors in a multicenter setting. METHODS: This was an unplanned post hoc analysis of a multicenter, prospective, nonrandomized trial that took place during 2011 to 2017 with 3 years of follow-up. Patients were placed into 3 groups based off procurement strategy: brain-dead donor (control), brain-dead donor evaluated by EVLP, and DCD donors evaluated by EVLP. The primary outcomes were severe primary graft dysfunction at 72 hours and survival. Secondary outcomes included select perioperative outcomes, and 1-year and 3-years allograft function and quality of life measures. RESULTS: The DCD EVLP group had significantly higher incidence of severe primary graft dysfunction at 72 hours (P = .03), longer days on mechanical ventilation (P < .001) and in-hospital length of stay (P = .045). Survival at 3 years was 76.5% (95% CI, 69.2%-84.7%) for the control group, 68.3% (95% CI, 58.9%-79.1%) for the brain-dead donor group, and 60.7% (95% CI, 45.1%-81.8%) for the DCD group (P = .36). At 3-year follow-up, presence observed bronchiolitis obliterans syndrome or quality of life metrics did not differ among the groups. CONCLUSIONS: Although DCD EVLP allografts might not be appropriate to transplant in every candidate recipient, the expansion of their use might afford recipients stagnant on the waitlist a viable therapy.

Complex repolarization dynamics in ex vivo human ventricles are independent of the restitution properties.

AIMS: The mechanisms of transition from regular rhythms to ventricular fibrillation (VF) are poorly understood. The concordant to discordant repolarization alternans pathway is extensively studied; however, despite its theoretical centrality, cannot guide ablation. We hypothesize that complex repolarization dynamics, i.e. oscillations in the repolarization phase of action potentials with periods over two of classic alternans, is a marker of electrically unstable substrate, and ablation of these areas has a stabilizing effect and may reduce the risk of VF. To prove the existence of higher-order periodicities in human hearts. METHODS AND RESULTS: We performed optical mapping of explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Signals recorded from the right ventricle endocardial surface were processed to detect global and local repolarization dynamics during rapid pacing. A statistically significant global 1:4 peak was seen in three of six hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of Periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. CONCLUSION: We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF.

Higher-Order Dynamics Beyond Repolarization Alternans in Ex-Vivo Human Ventricles are Independent of the Restitution Properties.

Background: Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., periods 4, 6, 8,...) are expected but have minimal experimental evidence. Methods: We studied explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Optical mapping of the transmembrane potential was performed after staining the hearts with voltage-sensitive fluorescent dyes. Hearts were stimulated at an increasing rate until VF was induced. Signals recorded from the right ventricle endocardial surface prior to induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results were correlated to the underlying electrophysiological characteristics as quantified by restitution curves and conduction velocity. Results: A prominent and statistically significant global 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel. Discussion: We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts. We infer from the independence of the period to the underlying restitution properties that the oscillation of the excitation-contraction coupling and calcium cycling mechanisms is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation and may provide targets for substrate-based ablation of VF.

Beyond Alternans: Detection of Higher-Order Periodicity in Ex-Vivo Human Ventricles Before Induction of Ventricular Fibrillation.

Background: Repolarization alternans, defined as period-2 oscillation in the repolarization phase of the action potentials, is one of the cornerstones of cardiac electrophysiology as it provides a mechanistic link between cellular dynamics and ventricular fibrillation (VF). Theoretically, higher-order periodicities (e.g., period-4, period-8,...) are expected but have very limited experimental evidence. Methods: We studied explanted human hearts, obtained from the recipients of heart transplantation at the time of surgery, using optical mapping technique with transmembrane voltage-sensitive fluorescent dyes. The hearts were stimulated at an increasing rate until VF was induced. The signals recorded from the right ventricle endocardial surface just before the induction of VF and in the presence of 1:1 conduction were processed using the Principal Component Analysis and a combinatorial algorithm to detect and quantify higher-order dynamics. Results: A prominent and statistically significant 1:4 peak (corresponding to period-4 dynamics) was seen in three of the six studied hearts. Local analysis revealed the spatiotemporal distribution of higher-order periods. Period-4 was localized to temporally stable islands. Higher-order oscillations (period-5, 6, and 8) were transient and primarily occurred in arcs parallel to the activation isochrones. Discussion: We present evidence of higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex-vivo human hearts before VF induction. This result is consistent with the period-doubling route to chaos as a possible mechanism of VF initiation, which complements the concordant to discordant alternans mechanism. The presence of higher-order regions may act as niduses of instability that can degenerate into chaotic fibrillation.

Epidemiology, management, and clinical outcomes of extrapulmonary Mycobacterium abscessus complex infections in heart transplant and ventricular assist device recipients.

Nontuberculous mycobacteria are emerging pathogens, yet data on the epidemiology and management of extrapulmonary nontuberculous mycobacteria infections in orthotopic heart transplantation (OHT) and ventricular assist device (VAD) recipients are scarce. We retrospectively reviewed records of OHT and VAD recipients who underwent cardiac surgery at our hospital and developed Mycobacterium abscessus complex (MABC) infection from 2013 to 2016 during a hospital outbreak of MABC linked to heater-cooler units. We analyzed patient characteristics, medical and surgical management, and long-term outcomes. Ten OHT patients and 7 patients with VAD developed extrapulmonary M. abscessus subspecies abscessus infection. The median time from presumed inoculation during cardiac surgery to the first positive culture was 106 days in OHT and 29 days in VAD recipients. The most common sites of positive cultures were blood (n = 12), sternum/mediastinum (n = 8), and the VAD driveline exit site (n = 7). The 14 patients diagnosed when alive received combination antimicrobial therapy for a median of 21 weeks, developed 28 antibiotic-related adverse events, and underwent 27 surgeries. Only 8 (47%) patients survived longer than 12 weeks after diagnosis, including 2 patients with VAD who experienced long-term survival after an explantation of infected VADs and OHT. Despite aggressive medical and surgical management, OHT and VAD patients with MABC infection experienced substantial morbidity and mortality.

A textile-reinforced composite vascular graft that modulates macrophage polarization and enhances endothelial cell migration, adhesion and proliferation in vitro.

At the present time, there is no successful off-the-shelf small-caliber vascular graft (<6 mm) for the repair or bypass of the coronary or carotid arteries. In this study, we engineer a textile-reinforced hydrogel vascular graft. The textile fibers are circularly knitted into a flexible yet robust conduit to serve as the backbone of the composite vascular graft and provide the primary mechanical support. It is embedded in the hydrogel matrix which seals the open structure of the knitted reinforcement and mediates cellular response toward a faster reendothelialization. The mechanical properties of the composite vascular graft, including bursting strength, suture retention strength and radial compliance, significantly surpass the requirement for the vascular graft application and can be adjusted by altering the structure of the textile reinforcement. The addition of hydrogel matrix, on the other hand, improves the survival, adhesion and proliferation of endothelial cells in vitro. The composite vascular graft also enhances macrophage activation and upregulates M1 and M2 related gene expression, which further improves the endothelial cell migration that might favor the reendothelialization of the vascular graft. Taken together, the textile-reinforced hydrogel shows it potential to be a promising scaffold material to fabricate a tissue engineered vascular graft.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2022 Update on Outcomes and Research.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database is the most mature and comprehensive cardiac surgery database. It is one of the most respected clinical data registries in health care, providing accurate risk-adjusted benchmarks, a foundation for quality measurement and improvement activities, and the ability to perform novel research. This report encompasses data from the years 2020 and 2021 and is the seventh in a series of reports that provide updated volumes, outcomes, database-related developments, and research summaries using the Adult Cardiac Surgery Database.

Progression of aortic valve insufficiency during centrifugal versus axial flow left ventricular assist device support.

OBJECTIVES: Long-term left ventricular assist device (LVAD) support can cause accelerated progression of aortic insufficiency (AI). The MOMENTUM trial has led to increased use of the HeartMate 3 (HM3) LVAD, due to greater hemocompatibility. However, the differential effect on the rate of progression of AI during HM3 support versus HeartMate 2 (HM2) has not been extensively studied. This analysis compares the rates of progression to moderate or severe AI (MSAI) comparing a cohort of patients supported with the HM2 versus HM3. METHODS: A retrospective review was performed on all consecutive patients implanted with HM2 or HM3 between May 2005 and June 2020. Follow-up time was limited to the first 6 years after LVAD implantation. Demographics and 4005 echocardiograms were assessed for 536 HM2 and 300 HM3 patients. The primary end point was progression to MSAI. Univariable and multivariable Cox proportional hazard regression and landmark analyses were performed. RESULTS: Progression to MSAI was greater in the HM2 (17%) versus HM3 (9.9%) cohort. On the univariable analysis, the hazard ratio for HM3 was 0.581 (95% confidence interval 0.370-0.909, P = 0.02) whereas on multivariable analysis hazard ratio was 0.624 (95% confidence interval 0.386-1.008, P = 0.0537). Preoperative AI, female sex and body surface area <2 were significantly associated with progression to MSAI. Landmark analysis suggests that LVAD type has the most significant effect on progression to MSAI between 1 and 2 years post-implantation. CONCLUSIONS: Current practice strategies achieved low rates of progression to MSAI. Preoperative AI, female sex and body surface area <2 were the most important predictors of progression to MSAI. Pump type appears to be of secondary importance.

Surgical Treatment of Tricuspid Valve Regurgitation in Patients Undergoing Left Ventricular Assist Device Implantation: Interim analysis of the TVVAD trial.

OBJECTIVES: Right heart failure remains a serious complication of left ventricular assist device therapy. Many patients presenting for left ventricular assist device implantation have significant tricuspid regurgitation. It remains unknown whether concurrent tricuspid valve surgery reduces postoperative right heart failure. The primary aim was to identify whether concurrent tricuspid valve surgery reduced the incidence of moderate or severe right heart failure within the first 6 months after left ventricular assist device implantation. METHODS: Patients with moderate or severe tricuspid regurgitation on preoperative echocardiography were randomized to left ventricular assist device implantation alone (no tricuspid valve surgery) or with concurrent tricuspid valve surgery. Randomization was stratified by preoperative right ventricular dysfunction. The primary end point was the frequency of moderate or severe right heart failure within 6 months after surgery. RESULTS: This report describes a planned interim analysis of the first 60 randomized patients. The tricuspid valve surgery group (n = 32) had mild or no tricuspid regurgitation more frequently on follow-up echocardiography studies compared with the no tricuspid valve surgery group (n = 28). However, at 6 months, the incidence of moderate and severe right heart failure was similar in each group (tricuspid valve surgery: 46.9% vs no tricuspid valve surgery: 50%, P = .81). There was no significant difference in postoperative mortality or requirement for right ventricular assist device between the groups. There were also no significant differences in secondary end points of functional status and adverse events. CONCLUSIONS: The presence of significant tricuspid regurgitation before left ventricular assist device is associated with a high incidence of right heart failure within the first 6 months after surgery. Tricuspid valve surgery was successful in reducing postimplant tricuspid regurgitation compared with no tricuspid valve surgery but was not associated with a lower incidence of right heart failure.

Incidence and Diagnostic Challenges of Bowel Ischemia after Continuous-flow Left Ventricular Assist Device Therapy.

Long-term continuous-flow left ventricular assist device (CFLVAD) therapy is limited by complications. Compared with stroke and renal dysfunction, post-CFLVAD bowel ischemia is poorly characterized. Adult patients who underwent first-time durable CFLVAD implantation at our institution between 2008 and 2018 were identified and screened for bowel ischemia using Current Procedural Terminology codes for abdominal surgical exploration and International Classification of Disease codes for intestinal vascular insufficiency. Patients who developed biopsy-proven bowel ischemia (cases) were matched to controls (1:1, nearest neighbor, caliper = 0.29) based on preoperative characteristics. Incidences of postoperative right heart failure and renal replacement therapy were compared using McNemar's test. One year survival was estimated using the Kaplan-Meier method. Overall, 711 patients underwent CFLVAD implantation. Nineteen (2.7%) developed bowel ischemia (cases) median 17 days postimplantation (IQR 8-71). The majority of cases were male (78.9%), Black (63.2%), received HeartMate II (57.9%), treated as destination therapy (78.9%), and had a history of hypertension (89.5%), chronic kidney disease (84.2%), hyperlipidemia (84.2%), smoking (78.9%), and atrial fibrillation (57.9%). Post-LVAD, case patients were more likely to develop moderate-severe right heart failure (89.5% vs. 68.4%, p = 0.005), require renal replacement therapy (21.1% vs. 0%, p < 0.001), and less likely to survive to discharge (52.6% vs. 89.5%, p = 0.02) compared with controls. Case subjects demonstrated worse 1 year survival. While less common than stroke and renal dysfunction, post-CFLVAD bowel ischemia is associated with high 1 year mortality. Multi-institutional registries should consider reporting abdominal complications such as bowel ischemia as an adverse event to further investigate these trends and identify predictors of this complication to reduce patient mortality.

A single center experience with minimally invasive approaches in congenital cardiac surgery.

BACKGROUND: Cardiac surgery is a technically demanding field with an appreciable learning curve that extends beyond formal training. Minimally invasive congenital cardiac surgery has one of the steepest learning curves. Early complications often discourage surgeons, particularly those at lower volume centers, from pursuing innovative approaches. Over the past three years, we have utilized a number of minimally invasive approaches including pulmonary valve replacement, anomalous aortic origin coronary artery repair, atrial septal defect repair, epicardial lead placement, and partial anomalous pulmonary venous return. Herein we report on our experience performing minimally invasive congenital cardiac surgery, lessons learned, and how our approach has evolved. METHODS: We performed a single institution, retrospective review, wherein continuous variables were reported as median (interquartile range). RESULTS: Between September 2017 and May 2020, minimally invasive approaches were attempted on 49 patients with a median age of 19 years (14-47 years) for nine distinct congenital cardiac diagnoses. Seven patients (14%) required conversion to larger incisions, including four patients or 36% of those undergoing anomalous aortic origin of a coronary artery repair. Patients who were converted had a higher body mass index 33.1 (31.7-37.8) than those who were not (24.2, 20.8-29.3) (P=0.009). CONCLUSIONS: Minimally invasive approaches for congenital cardiac conditions require a team approach. Patients with a body mass index greater than 30 should be counseled on the higher rate of conversion. We no longer perform minimally invasive anomalous aortic origin of a coronary artery repair given the high rate of conversions and complications. Surgeons attempting this procedure should do so cautiously.

Anomalous Aortic Origin of a Coronary Artery Repair Through an Anterior Minithoracotomy.

OBJECTIVE: The benefits of minimally invasive adult cardiac surgery are well established. Nevertheless, minimally invasive congenital cardiac procedures, even for adult patients, are uncommon. In 2018, we started repairing anomalous aortic origin of a coronary artery (AAOCA) through a 5 cm anterior minithoracotomy when possible to improve cosmesis and avoid sternal precautions. We hypothesized this approach was safe and reliable. METHODS: A 5 cm incision was made in the right second intercostal space. The incision was carried down to the pericardium while preserving the internal mammary artery. With the pericardium in view, the second and third ribs were disarticulated. Central cardiopulmonary bypass was established, and the repair was carried out based on the patient's anatomy. The technique was modified to a left anterior minithoracotomy for 1 patient who required pulmonary artery translocation. At any point, if the dissection or repair was not progressing appropriately, the minimally invasive exposure was converted to a partial or traditional median sternotomy. RESULTS: Between June 2018 and June 2019, 11 patients underwent minimally invasive anomalous coronary repair. Four patients (3 with body mass index >30) were converted to traditional sternotomy due to poor visualization. Postoperatively, 1 patient required coronary artery bypass after 335 days, due to extensive collaterals and stable angina. Otherwise, at a median follow-up of 437 days (IQR 340 to 480), patients had resumed baseline activity without recurrent symptoms. CONCLUSIONS: Minimally invasive AAOCA repair may be appealing, although surgeons should be cautious given the high conversion rate.

Invasive Mycobacterium abscessus Complex Infection After Cardiac Surgery: Epidemiology, Management, and Clinical Outcomes.

BACKGROUND: We recently mitigated a clonal outbreak of hospital-acquired Mycobacterium abscessus complex (MABC), which included a large cluster of adult patients who developed invasive infection after exposure to heater-cooler units during cardiac surgery. Recent studies have detailed Mycobacterium chimaera infections acquired during cardiac surgery; however, little is known about the epidemiology and clinical courses of cardiac surgery patients with invasive MABC infection. METHODS: We retrospectively collected clinical data on all patients who underwent cardiac surgery at our hospital and subsequently had positive cultures for MABC from 2013 through 2016. Patients with ventricular assist devices or heart transplants were excluded. We analyzed patient characteristics, antimicrobial therapy, surgical interventions, and clinical outcomes. RESULTS: Ten cardiac surgery patients developed invasive, extrapulmonary infection from M. abscessus subspecies abscessus in an outbreak setting. Median time from presumed inoculation in the operating room to first positive culture was 53 days (interquartile range [IQR], 38-139 days). Disseminated infection was common, and the most frequent culture-positive sites were mediastinum (n = 7) and blood (n = 7). Patients received a median of 24 weeks (IQR, 5-33 weeks) of combination antimicrobial therapy that included multiple intravenous agents. Six patients required antibiotic changes due to adverse events attributed to amikacin, linezolid, or tigecycline. Eight patients underwent surgical management, and 6 patients required multiple sternal debridements. Eight patients died within 2 years of diagnosis, including 4 deaths directly attributable to MABC infection. CONCLUSIONS: Despite aggressive medical and surgical management, invasive MABC infection after cardiac surgery caused substantial morbidity and mortality. New treatment strategies are needed, and compliance with infection prevention guidelines remains critical.

Mitigating the Impact of Using Female Donor Hearts in Male Recipients Using BMI Difference.

BACKGROUND: Heart transplantation is limited by the supply of donor organs. Previous studies have associated female donor to male recipient with decreased posttransplant survival. We wanted to evaluate whether this risk can be mitigated using higher donor than recipient body mass index (BMI). METHODS: We performed a retrospective analysis of the Organ Procurement and Transplantation Network/United Network of Organ Sharing registry encompassing years 2005 to 2018 for all male adult recipients (>18 years of age) who underwent isolated heart transplantation with grafts from female donors. The association between donor and recipient BMI difference and recipient survival was evaluated using adjusted Cox proportional hazards modeling. RESULTS: A total of 3788 male recipients who received female donor hearts met inclusion criteria for analysis. Maximally selected rank statistics identified donor minus recipient BMI of 1.5 kg/m2 as a meaningful cutoff point in the analysis of recipient survival. Multivariable Cox proportional hazards analysis demonstrated that increasing donor BMI relative to recipient BMI up to this cutoff point was associated with improved survival (hazard ratio per 5-unit difference, 0.87; 95% confidence interval, 0.77-0.99). Above this cutoff point, increasing donor BMI relative to the recipient did not improve survival more than what was achieved by adding 1.5 of BMI difference (hazard ratio per 5-unit difference, 0.97; 95% confidence interval, 0.90-1.04). CONCLUSIONS: Increasing donor BMI relative to recipient BMI up to 1.5 kg/m2 greater than recipient BMI was associated with improved survival. BMI difference may be useful as a simple surrogate for predicted heart mass difference to help mitigate the impact of sex mismatch in heart transplantation.

Right Anterior Mini-Incision Approach to Anomalous Right Coronary Artery Repair.

The right anterior mini-incision has emerged as an effective minimally invasive approach for adult aortic root and valve operations. However, adoption of minimally invasive techniques has been limited in congenital heart surgery. We report a case of anomalous aortic origin of the right coronary artery repair performed through this approach. Following successful right coronary artery unroofing, the patient had an uncomplicated postoperative hospitalization.

Stroke risk following implantation of current generation centrifugal flow left ventricular assist devices.

BACKGROUND AND AIM: Stroke remains a significant complication of left ventricular assist device (LVAD) therapy. We performed a single-center retrospective study evaluating patients undergoing first-time HeartWare HVAD (Medtronic Inc) or HeartMate 3 (Abbott Inc) implantation from September 2009-February 2018. METHODS: Exclusion criteria were age <18 and preoperative ECMO. The primary endpoint was stroke-free survival. Stroke was defined as new neurological deficits persisting >24 hours with corresponding radiographic evidence. Risk factors evaluated included demographics, medical comorbidities, heart failure etiology, LVAD indication, INTERMACS profile, and device type. Univariate predictors (P < .15) and variables clinically suspected to raise stroke risk were entered in a multivariate hazard regression model, specified using backward selection of covariates and accounting for competing risks of transplant/LVAD exchange. RESULTS: A total of 163 HVAD and 84 HM3 patients were analyzed. Median follow up (until death, censoring for transplant/LVAD removal, or end of follow up) was 1.2 years in HVAD patients and 1.4 years in HM3 patients. Stroke occurred in 24 HVAD patients (15 ischemic, 9 hemorrhagic) and 6 HM3 patients (4 ischemic, 2 hemorrhagic). One-year stroke-free survival was 76.8% for HVAD and 84.3% for HM3. Thirty-day mortality following stroke was 41.7% for HVAD and 66.7% for HM3; 54.2% of HVAD strokes were disabling compared to 83.3% of HM3 strokes. Age, LVAD indication, and device type were associated (P < .15) with stroke on univariate analysis. On multivariate analysis, the HVAD was associated with significantly higher stroke risk (hazard ratio, 2.57; 95% confidence interval, 1.02-6.44; P = .045). CONCLUSIONS: Different LVAD models appear to be associated with significantly different stroke risks.

Early outcomes with durable left ventricular assist device replacement using the HeartMate 3.

BACKGROUND: The HeartMate 3 (HM3) left ventricular assist device (LVAD) (Abbott, Inc, Chicago, Ill) is a fully magnetically levitated centrifugal implantable pump used to treat patients with chronic heart failure. The MOMENTUM (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3) trial demonstrated that patients treated with the HM3 experienced reduced need for reoperation for LVAD replacement compared with a control group receiving an axial flow design, Heartmate II (Abbott, Inc). However, there are few reports of using HM3 as the replacement pump in patients who already are supported by a durable LVAD and experience a device-related complication necessitating replacement. METHODS: An institutional LVAD database was used to identify 19 consecutive patients who underwent pump replacement to HM3 (group 1) versus 85 consecutive control patients who underwent pump replacement to either Heartmate II or HeartWare Ventricular Assist Device (Medtronic Inc, Minneapolis, Minn) (group 2), at a single institution from January 2010 to August 2018. Patient baseline characteristic and outcomes were obtained from a prospectively maintained database. The primary endpoint was a composite of freedom from death or need for another replacement surgery. RESULTS: There was no difference between the groups in heart failure etiology, indication for replacement, as well as the average days on the previous pump or the type of previous pump. The HM3 group did have a significantly greater body mass index (37 vs 31.6 P = .01), a greater number of previous LVAD implants (36.8% vs 5.9%, had 2 previous LVADs, P < .001), and a greater number of previous sternotomies (31.6% vs 7.1%, had 3 previous sternotomies, P = .001). No difference was found between the groups in terms of postoperative adverse event rates. With regards to the primary endpoint, the patients with HM3 replacements (group 1) versus group 2 experienced significantly greater freedom from either death or need for another replacement during the follow-up period (P = .039). During follow-up, there were no thrombosis events for the patients who received replacement with HM3. CONCLUSIONS: LVAD replacement with HM3 can be performed safely and may be considered as the pump of choice in patients requiring LVAD replacement.