Outcomes of heart transplant recipients bridged with percutaneous versus durable left ventricular assist devices.

BACKGROUND: The new United Network for Organ Sharing (UNOS) heart allocation policy prioritizes temporary percutaneous over durable left ventricular assist devices (LVAD) as bridge to transplant. We sought to examine 1-year outcomes of heart transplant recipients bridged with Impella versus durable LVADs. METHODS: All primary adult orthotopic heart transplant recipients registered in UNOS between January 2016 and June 2021 were analyzed. Recipients were identified as being bridged with isolated durable or percutaneous LVAD at the time of transplant. Baseline characteristics were compared and 1-year survival was examined using the Kaplan Meier method and multivariable Cox proportional hazards regression. RESULTS: During our study period, heart transplant recipients bridged with LVADs were divided between 5422(94%) durable and 324(6%) percutaneous options. Impella-bridged recipients were more likely to be status 1A under the old allocation system (98% vs. 70%, p < .01) and status 2 or higher under the new allocation system (99% vs. 24%, p < .01). Impella-bridged recipients were less likely to be obese (27% vs. 42%, p < .01), have ischemic cardiomyopathy (27% vs. 34%, p < .01), and were more likely to be on inotropic agents at the time of transplant (68% vs. 6%, p < .01). One-year post-transplant survival was not significantly different between the two groups on univariable (HR .87, 95% CI .56-1.37) or multivariable analysis (aHR .63, 95% CI .37-1.07). CONCLUSIONS: Following the UNOS allocation policy change, Impella utilization has increased with no significant difference in 1-year survival compared to bridge with durable LVADs. Impella may be a reasonable alternative to durable LVADs in select patients.

Transcatheter Aortic Valve Replacement for Severe Aortic Valve Stenosis: Do Patients Experience Better Quality of Life Regardless of Gradient?

BACKGROUND: Aortic valve replacement improves survival for patients with low-gradient aortic valve stenosis, but there is a paucity of data on postoperative quality of life for this population. METHODS: In a single-center retrospective analysis of 304 patients with severe aortic valve stenosis who underwent transcatheter aortic valve replacement, patients were divided into 4 groups based on mean pressure gradient, left ventricular ejection fraction, and stroke volume index. Using the Kansas City Cardiomyopathy Questionnaire-12, quality of life was assessed immediately before and 1 month after transcatheter aortic valve replacement. RESULTS: Most patients in the low-flow, low-gradient group were men; this group had higher relative rates of cardiovascular disease and type 2 diabetes than the paradoxical low-flow, low-gradient group; the normal-flow, low-gradient group; and the high-gradient group. All-cause mortality did not differ significantly among the groups at 1 month after surgery, and all groups experienced a significant improvement in quality-of-life scores after surgery. The mean improvement was 27 points in the low-flow, low-gradient group, 25 points in the paradoxical low-flow, low-gradient group, 30 points in the normal-flow, low-gradient group, and 30 points in the high-gradient group (all P < .001). CONCLUSION: Quality of life improves significantly across all subgroups of aortic valve stenosis after trans-catheter aortic valve replacement, regardless of flow characteristics or aortic valve gradients.

Nontechnical skills training in cardiothoracic surgery: A pilot study.

OBJECTIVE: The importance of nontechnical skills in surgery is widely recognized. We demonstrate the feasibility of administering and assessing the results of a formal Non-Technical Skills in Surgery (NOTSS) curriculum to cardiothoracic surgery residents. METHODS: Eight cardiothoracic surgery residents participated in the NOTSS curriculum. They were assessed on their cognitive (situation awareness, decision-making) and social (communication and teamwork, leadership) skills based on simulated vignettes. The residents underwent pretraining NOTSS assessments followed by self-administered confidence ratings regarding the 4 skills. Subsequently, a formal NOTSS lecture was delivered and additional readings from the NOTSS textbook was assigned. A month later, the residents returned for post-training NOTSS assessments and self-administered confidence ratings. Changes across days (or within-day before vs after curriculum) were assessed using Wilcoxon signed rank test. RESULTS: There was a significant improvement in the overall NOTSS assessment score (P = .01) as well as in the individual categories (situation awareness, P = .02; decision-making, P = .02; communication and teamwork, P = .01; leadership, P = .02). There was also an increase in resident self-perception of improvement on the post-training day (P = .01). CONCLUSIONS: We have developed a simulation-based NOTSS curriculum in cardiothoracic surgery that can be formally integrated into the current residency education. This pilot study indicates the feasibility of reproducible assessments by course educators and self-assessments by participating residents in nontechnical skills competencies.

Validity of echocardiography for detection of left ventricular thrombus with surgical validation in patients awaiting durable left ventricular assist device.

OBJECTIVE: Unrecognized left ventricular thrombi (LVT) can have devastating clinical implications and precludes patients with end-stage heart failure from undergoing left ventricular assist device (LVAD) implantation without cardiopulmonary bypass assistance. We assessed the reliability of an echocardiogram to diagnose LVT in patients with end-stage heart disease who underwent LVAD implantation. METHODS: A single-center retrospective study evaluated 232 consecutive adult patients requiring implantation of durable LVADs between 2005 and 2019. The validity of preoperative transthoracic echocardiogram (TTE) and intraoperative transesophageal echocardiogram (TEE) for diagnosing LVT was compared to direct inspection at the time of LVAD implantation. RESULTS: There were 232 patients that underwent LVAD implantation, with 226 patients (97%) receiving a preoperative TTE. Of those 226 patients, 32 patients (14%) received ultrasound enhancing agents (UEA). Intraoperative TEE images were available in 195 patients (84%). The sensitivity of TTE without UEA was 22% and specificity was 90% for detecting LVT, compared to 50% and 86%, respectively, for TTE with UEA. For intraoperative TEE, the sensitivity and specificity were 46% and 96%, respectively. The false omission rate ranged from 4% to 8% for all modalities of echocardiography. CONCLUSION: Among patients undergoing LVAD implantation, preoperative TTE and intraoperative TEE had poor sensitivity for LVT detection. Up to 8% of echocardiograms were incorrectly concluded to be negative for LVT on surgical validation. The low sensitivity and positive predictive value for diagnosing LVT suggest that echocardiography has limited reliability in this cohort of patients who are at high risk of LVT formation and its subsequent complications.

Minimally Invasive Repair of Ascending Aortic Pseudoaneurysms: An Alternative to Open Surgical Repair in High-Risk Patients.

Development of a pseudoaneurysm of the ascending aorta is an uncommon complication of aortic surgery. Several nonsurgical techniques are available for treatment of ascending aortic pseudoaneurysms (AAPs). This report outlines a single-center retrospective experience with 14 nonsurgical procedures for treatment of AAPs in 10 patients. Modified stent grafts, septal defect occlusion devices, coil embolics, and liquid embolics were deployed by transthoracic and endovascular approaches. Complete stasis of the AAP was achieved in 7 of 10 patients (70%). Mean postprocedural recoveries occurred within 3.5 days. Nonsurgical techniques for repair of AAPs offer a comparatively safe and effective alternative to open surgical repair.

Pretransplant malignancy among lung transplant recipients in the modern era.

BACKGROUND: Malignancy is a relative contraindication in transplant candidates, given the increased neoplastic risk accompanying posttransplant immunosuppression. However, the number of patients receiving a lung transplant despite pretransplant malignancy is rising, and their outcomes remain unclear. Our purpose was to examine the outcomes of lung transplant recipients with pretransplant malignancy in the modern era. METHODS: We evaluated the United Network for Organ Sharing registry for adult lung transplants that were completed between June 2005 and September 2016. Transplant recipients were stratified by pretransplant malignancy, with subgroup analysis by sex and active malignancy. The primary outcome was 5-year survival and the secondary outcome was cause of death. Kaplan-Meier estimates illustrated 5-year survival and multivariable Cox proportional hazards regressions controlled for demographics and comorbidities. RESULTS: Of 18,032 transplant patients, 1,321 transplant recipients (7.3%) possessed a pretransplant malignancy. Patients with pretransplant malignancy faced significantly greater mortality within 5 years (36.0% vs 32.8%, P = .017), an effect greatest in men with pretransplant malignancy (39.2% vs 33.7%, P = .002). Patients with pretransplant malignancy also faced greater risk of death from posttransplant malignancy (15.6% vs 9.4%, P < .001), particularly for those with active malignancy at transplant (34.8% vs 9.8%, P < .001). Pretransplant malignancy remained a significant predictor of 5-year mortality in adjusted Cox regressions (hazard ratio: 1.16 [1.05-1.27], P = .003). CONCLUSION: Patients with pretransplant malignancy, and particularly men with pretransplant malignancy and those with active malignancy at transplant, are at an increased risk of 5-year mortality and posttransplant death from malignancy. Balancing individual risk of posttransplant malignancy with immunosuppressive care is necessary to optimize outcomes for pretransplant malignancy patients.

Clinical phenomapping and outcomes after heart transplantation.

BACKGROUND: Survival after heart transplantation (HTx) is limited by complications related to alloreactivity, immune suppression, and adverse effects of pharmacologic therapies. We hypothesize that time-dependent phenomapping of clinical and molecular data sets is a valuable approach to clinical assessments and guiding medical management to improve outcomes. METHODS: We analyzed clinical, therapeutic, biomarker, and outcome data from 94 adult HTx patients and 1,557 clinical encounters performed between January 2010 and April 2013. Multivariate analyses were used to evaluate the association between immunosuppression therapy, biomarkers, and the combined clinical end point of death, allograft loss, retransplantation, and rejection. Data were analyzed by K-means clustering (K = 2) to identify patterns of similar combined immunosuppression management, and percentile slopes were computed to examine the changes in dosages over time. Findings were correlated with clinical parameters, human leucocyte antigen antibody titers, and peripheral blood mononuclear cell gene expression of the AlloMap (CareDx, Inc., Brisbane, CA) test genes. An intragraft, heart tissue gene coexpression network analysis was performed. RESULTS: Unsupervised cluster analysis of immunosuppressive therapies identified 2 groups, 1 characterized by a steeper immunosuppression minimization, associated with a higher likelihood for the combined end point, and the other by a less pronounced change. A time-dependent phenomap suggested that patients in the group with higher event rates had increased human leukocyte antigen class I and II antibody titers, higher expression of the FLT3 AlloMap gene, and lower expression of the MARCH8 and WDR40A AlloMap genes. Intramyocardial biomarker-related coexpression network analysis of the FLT3 gene showed an immune system-related network underlying this biomarker. CONCLUSIONS: Time-dependent precision phenotyping is a mechanistically insightful, data-driven approach to characterize patterns of clinical care and identify ways to improve clinical management and outcomes.

Tricuspid valve regurgitation after heart transplantation.

Tricuspid valve regurgitation (TVR) in the orthotopic heart transplant (OHT) recipient is quite common and has varied clinical sequelae. In its severest forms, it can lead to right-sided failure symptoms indistinguishable from that seen in native heart TVR disease. While certain implantation techniques are widely recognized to reduce the risk of TVR in the cardiac allograft, concomitant tricuspid annuloplasty, while having advocates, is not currently accepted as a routinely established adjunct. Decisions to surgically correct TVR in the OHT recipient must be made carefully, as certain clinical scenarios have high risk of failure. Like in the native heart, anatomic etiologies typically have the greatest chances for success compared to functional etiologies. While repair options have been utilized, there is emerging data to support replacement as the more durable option. While mechanical prostheses are impractical in the heart transplant recipient, biologic valves offer the advantage of continued access to the right ventricle for biopsies in addition to acceptable durability in the low pressure system of the right side.

The In-Hospital Cost of Ventricular Assist Device Therapy: Implications for Patient Selection.

Ventricular assist device (VAD) therapy is increasingly utilized to support patients in end-stage heart failure. However, VAD programs are resource intensive and demand active monitoring to ensure long-term sustainability. The purpose of this study was to analyze total cost trends of the VAD program at our academic medical center. Retrospective analysis of University of California - Los Angeles's VAD program between 2013 and 2014 was performed. Total in-hospital costs from the date of VAD surgery admission were queried and normalized to a z score. Multivariable linear regression analysis with step-wise elimination was used to model total costs. Overall, 42 patients received a VAD during the study period, with 19 (45%) receiving biventricular support. On univariate analysis, high body mass index, biventricular support, time between VAD implantation and discharge, and total length of hospital stay were correlated with higher costs (all p < 0.02). On multivariable analysis, time between VAD implantation and discharge and biventricular support remained significantly related to total costs (overall R = 0.831, p < 0.001). The time between VAD implantation and discharge and the use of biventricular support were the most predictive factors of total cost in our VAD population. Reducing hospital stay post-VAD implantation is important in minimizing the cost of VAD care.

Characterization of ventricular assist device-mediated sensitization in the bridge-to-heart-transplantation patient.

OBJECTIVE: Ventricular assist devices (VADs) are associated with increased anti-human leukocyte antigen antibody production. The purpose of this study is to characterize differences in sensitization patterns in patients receiving axial flow, implantable VADs versus pulsatile, paracorporeal biventricular assist devices (BIVADs) as bridges to transplantation. METHODS: The study is a retrospective review of 68 patients who were bridged to transplantation with either a VAD or a BIVAD, as described, from January 2007 to June 2010, at a university medical center. RESULTS: Five of 15 (33.3%) VAD patients became sensitized during treatment, compared with 30 of 53 (56.6%) BIVAD patients, P = .15. Multivariable analysis comparing BIVAD with VAD, while controlling for previous cardiac surgery, pregnancy, and packed red blood cell transfusion produced an odds ratio of 2.99, P = .14. Of sensitized patients, all 5 (100%) of the VAD patients had pre-existing antibodies before VAD placement, compared with 9 of 30 (30.0%) BIVAD patients, P = .006. Maximum cumulative mean fluorescence intensities for BIVAD were 46,259 ± 66,349 versus 42,540 ± 12,840 for VAD, P = .90. Time to maximum antibody expression was shorter for the VAD group (34 ± 28 days vs 5.8 ± 9 days, P = .04). CONCLUSIONS: Device type was not a factor in patient sensitization after implantation. However, VAD patients required pre-existing sensitization before implantation to produce antibodies during their treatment interval, whereas more than two thirds of BIVAD patients developed de novo antibodies. These data suggest that the mechanism of sensitization between VAD and BIVAD patients may differ, and further mechanistic studies into the impact of device types on patient sensitization are warranted.

Primary graft dysfunction does not lead to increased cardiac allograft vasculopathy in surviving patients.

OBJECTIVE: Early injury is associated with the development of cardiac allograft vasculopathy in heart transplantation. We examined whether adult heart transplant recipients surviving primary graft dysfunction were more susceptible to the development of cardiac allograft vasculopathy than their nonprimary graft dysfunction counterparts. METHODS: A total of 857 patients who underwent heart transplantation between January 1994 and December 2008 at our institution were reviewed. Primary graft dysfunction was defined as the need for extracorporeal membrane oxygenation, open chest, or intra-aortic balloon pump placement within 72 hours of transplantation. Cardiac allograft vasculopathy was defined as ≥50% coronary artery stenosis in any vessel. Allograft survival was defined by patient death or need for retransplantation. RESULTS: Completed follow-up was available for 32 patients in the primary graft dysfunction group and 701 patients in the nonprimary graft dysfunction group. Mean recipient ages (56 years vs 55 years, respectively; P = .50) and ischemic times (220 minutes vs 208 minutes, respectively; P = .35) were similar. Donor age was significantly higher in the primary graft dysfunction group (38 years vs 32 years, P = .02). Five-year survivals for the primary graft dysfunction and nonprimary graft dysfunction groups were 46.9% versus 78.9% (P < .001). Conditional 5-year survivals in patients surviving the first year were 78.9% and 88.3% for the primary graft dysfunction and nonprimary graft dysfunction groups, respectively (P = .18). Within a 30-day postoperative period, there were more deaths in the primary graft dysfunction group (28.1% vs 2.3%, P < .0001) and more retransplants (6.25% vs 0%, P = .002). Of the patients surviving past 30 days, only 2 (8.7%) of the primary graft dysfunction patients developed cardiac allograft vasculopathy versus 144 (21.0%) in the nonprimary graft dysfunction group (P < .001). CONCLUSIONS: Primary graft dysfunction was associated with lower 30-day, 1-year, and 5-year allograft survival rates. Surviving patients, however, did not show increased tendency toward cardiac allograft vasculopathy development.

Surgical procedures for patients receiving mechanical cardiac support.

Mechanical cardiac support devices are used for patients with cardiopulmonary failure. We reviewed our institutional experience with noncardiac surgical procedures (NCPs) in patients supported by ventricular assist devices (VADs, n = 198) or extracorporeal membrane oxygenation (ECMO, n = 165) between July 1998 and June 2010. In total, 64 NCPs were performed in 55 VAD patients and 14 NCPs in 14 ECMO patients. Thirty-day mortality was higher for the VAD compared with the ECMO group (25 vs 86%; P < 0.001) and was greater for emergent compared with nonemergent procedures (58 vs 19%; P < 0.001). Excluding tracheostomy, no patients died within 30 days of a nonemergent procedure. Kaplan-Meier survival showed a trend toward worse survival after NCP in ECMO patients, but NCP did not alter survival in VAD patients. Fewer VAD patients were bridged to heart transplantation when NCP was required, and time from device implantation to transplant was significantly longer than for patients without NCP. In summary, this is the largest series of NCPs on VAD support and the only series on ECMO. Mortality is substantial for ECMO patients. Selected procedures can be performed safely in VAD patients but will delay heart transplantation.

Use of ventricular assist device as a bridge to cardiac transplantation: impact of age and other determinants on outcomes.

We sought to compare outcomes in patients > or = 60 years of age with those of their younger counterparts who underwent ventricular assist device implantation intended as a bridge to cardiac transplantation and also to identify retrospectively additional pre- and postoperative factors that might portend adverse outcomes.The medical records of 88 patients who were treated with bridge-to-transplantation ventricular assist devices from 1996 through 2007 were reviewed. Laboratory values, hemodynamic parameters, and the need for hemodynamic support were evaluated. Postoperative complications and bridge-to-transplantation success rates versus death rates were evaluated. Seventeen patients were > or = 60 years old and 71 patients were < 60 years old. In the older group, 59% of patients underwent successful bridging to transplantation, compared with 69% of the younger patients (P = 0.41). Multivariate analysis distinguished age > or = 60, female sex, earlier time period of operation, higher mean pulmonary arterial and central venous pressures, need for preoperative intra-aortic balloon pumps, and postoperative respiratory failure as independent risk factors for death. After orthotopic heart transplantation, survival to hospital discharge was 100% in the older group and 93.9% in the younger patients. Median lengths of stay were similar in both age categories.Multivariate analysis identified age as 1 of 6 independent risk factors for death in this study. Patients who successfully underwent cardiac transplantation, however, had similar survival statistics regardless of age category. Case-by-case evaluation is warranted when analyzing risk-benefit ratios of bridge-to-transplantation ventricular assist device therapy in the older patient population.