The Society of Thoracic Surgeons Intermacs 2023 Annual Report: Focus on Magnetically Levitated Devices.

The 14th Annual Report from The Society of Thoracic Surgeons (STS) Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) describes outcomes of 27,493 patients with a continuous-flow left ventricular assist device (LVAD) from the past decade (2013-2022). In 2022, 2517 primary LVADs were implanted, of which 2512 (99.8%) were fully magnetically levitated (Mag-Lev) devices. This shift to nearly exclusive use of a Mag-Lev device led us to examine its outcomes compared with contemporary (2018-2022) and historical (2013-2017) non-Mag-Lev cohorts. Patients supported by a Mag-Lev device (n = 10,920) had a higher 1- and 5-year survival of 86% (vs 79% and 81%, P < .0001) and 64% (vs 44% and 44%, P < .0001), respectively, than those receiving non-Mag-Lev devices during the contemporary and historical eras. Over 5 years, freedom from gastrointestinal bleeding (72% vs 60%, P < .0001), stroke (87% vs 67%, P < .0001), and device malfunction/pump thrombus (83% vs 54%, P < .0001), but not device-related infection (61% vs 64%, P = .93), was higher with Mag-Lev devices compared with non-Mag-Lev support during the contemporary era. In this large primacy cohort of real-world patients with advanced heart failure, this report underscores marked improvements in short- and intermediate-term survival and reduction of adverse events with a contemporary Mag-Lev LVAD.

Aspirin and Hemocompatibility Events With a Left Ventricular Assist Device in Advanced Heart Failure: The ARIES-HM3 Randomized Clinical Trial.

IMPORTANCE: Left ventricular assist devices (LVADs) enhance quality and duration of life in advanced heart failure. The burden of nonsurgical bleeding events is a leading morbidity. Aspirin as an antiplatelet agent is mandated along with vitamin K antagonists (VKAs) with continuous-flow LVADs without conclusive evidence of efficacy and safety. OBJECTIVE: To determine whether excluding aspirin as part of the antithrombotic regimen with a fully magnetically levitated LVAD is safe and decreases bleeding. DESIGN, SETTING, and PARTICIPANTS: This international, randomized, double-blind, placebo-controlled study of aspirin (100 mg/d) vs placebo with VKA therapy in patients with advanced heart failure with an LVAD was conducted across 51 centers with expertise in treating patients with advanced heart failure across 9 countries. The randomized population included 628 patients with advanced heart failure implanted with a fully magnetically levitated LVAD (314 in the placebo group and 314 in the aspirin group), of whom 296 patients in the placebo group and 293 in the aspirin group were in the primary analysis population, which informed the primary end point analysis. The study enrolled patients from July 2020 to September 2022; median follow-up was 14 months. Intervention: Patients were randomized in a 1:1 ratio to receive aspirin (100 mg/d) or placebo in addition to an antithrombotic regimen. MAIN OUTCOMES AND MEASURES: The composite primary end point, assessed for noninferiority (-10% margin) of placebo, was survival free of a major nonsurgical (>14 days after implant) hemocompatibility-related adverse events (including stroke, pump thrombosis, major bleeding, or arterial peripheral thromboembolism) at 12 months. The principal secondary end point was nonsurgical bleeding events. RESULTS: Of the 589 analyzed patients, 77% were men; one-third were Black and 61% were White. More patients were alive and free of hemocompatibility events at 12 months in the placebo group (74%) vs those taking aspirin (68%). Noninferiority of placebo was demonstrated (absolute between-group difference, 6.0% improvement in event-free survival with placebo [lower 1-sided 97.5% CI, -1.6%]; P < .001). Aspirin avoidance was associated with reduced nonsurgical bleeding events (relative risk, 0.66 [95% confidence limit, 0.51-0.85]; P = .002) with no increase in stroke or other thromboembolic events, a finding consistent among diverse subgroups of patient characteristics. CONCLUSIONS AND RELEVANCE: In patients with advanced heart failure treated with a fully magnetically levitated LVAD, avoidance of aspirin as part of an antithrombotic regimen, which includes VKA, is not inferior to a regimen containing aspirin, does not increase thromboembolism risk, and is associated with a reduction in bleeding events. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04069156.

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.

Gender and Race Differences in HeartMate3 Left Ventricular Assist Device as a Bridge to Transplantation.

BACKGROUND: Gender and racial disparities exist after left ventricular assist device (LVAD) implantation. Compared with older devices, the HeartMate 3 (HM3) (Abbott Cardiovascular) has demonstrated improved survival. Whether HM3 differentially improves outcomes by gender or race and ethnic groups is unknown. OBJECTIVES: The purpose of this study is to examine differences by gender and race in the use of HM3 among patients listed for heart transplantation (HT) and associated waitlist and post-transplant outcomes. METHODS: The authors examined all patients (20% women, 33% Black) who received LVADs as bridge to transplantation (BTT) between January 2018 and June 2020, in the OPTN (Organ Procurement and Transplantation Network) database. Trends in use of HM3 were evaluated by gender and race. Competing events of death/delisting and transplantation were evaluated using subdistribution hazard models. Post-transplant outcomes were evaluated using multivariate logistic regression adjusted for demographic, clinical, and donor characteristics. RESULTS: Of 11,524 patients listed for HT during the study period, 955 (8.3%) had HM3 implanted as BTT. Use of HM3 increased for all patients, with no difference in use by gender (P = 0.4) or by race (P = 0.2). Competing risk analysis did not demonstrate differences in transplantation or death/delisting in men compared with women (HT: adjusted HR [aHR]: 0.92 [95% CI: 0.70-1.21]; death/delisting: aHR: 0.91 [95% CI: 0.59-1.42]), although Black patients were transplanted fewer times than White patients (HT: aHR: 0.72 [95% CI: 0.57-0.91], death/delisting: aHR: 1.36 [95% CI: 0.98-1.89]). One-year post-transplant survival was comparable by gender (aHR: 0.52 [95% CI: 0.21-1.70]) and race (aHR: 0.76 [95% CI: 0.34-1.70]), with no differences in rates of stroke, acute rejection, or graft failure. CONCLUSIONS: Use of HM3 among patients listed for HT has increased over time and by gender and race. Black patients with HM3 were less likely to be transplanted compared with White patients, but there were no differences in post-transplant outcomes between these groups or between men and women.

Heart transplantation in Val142Ile mutation in the modern era: A single center experience.

Little is known about the post heart transplantation management of extra cardiac manifestations in patients with hereditary transthyretin amyloid cardiomyopathy (hATTR-CM) in the new era of disease modifying treatment for ATTR amyloidosis. This is a retrospective study of all patients with hATTR-CM associated with the Val142Ile variant who underwent heart transplantation (HT) from January 2014 to February 2022. All 10 patients with the Val142Ile mutation were successfully transplanted, with a 1 year survival post heart transplantation (HT) of 90%, comparable to an age, sex, and race matched cohort of patients transplanted for non-amyloid indications. However, 4 (40%) of these patients developed progressive extracardiac manifestations requiring initiation of TTR silencer therapy with the small interfering RNA (siRNA) drug patisiran, which was well tolerated with no significant side effects in this population. We recommend formal neurologic evaluation and assessment of extracardiac manifestations annually as part of routine post-transplant care, and disease modifying therapy, aimed at TTR stabilization or silencing, should be initiated in the context of previously untreated extracardiac manifestations or evidence of subclinical neuropathy to prevent progression.

Outflow graft obstruction after left ventricular assist device implantation: a retrospective, single-centre case series.

AIMS: Outflow graft obstruction is a poorly described complication following left ventricular assist device (LVAD) surgery. We sought to define the incidence of LVAD outflow graft obstruction and assess clinical outcomes with a percutaneous treatment strategy. METHODS AND RESULTS: From January 2012 to October 2020, 322 patients with LVAD were managed at our institution. Patients with LVAD outflow graft obstruction were identified by cardiac computed tomography with angiography and invasive haemodynamic assessment and were subsequently treated with percutaneous intervention. Poisson regression was used to analyse time-dependent differences in the incidence of LVAD outflow graft obstruction. Kaplan-Meier analysis was used to estimate survival. Twenty patients (6.2%) developed haemodynamically significant LVAD outflow graft obstruction at a rate of 0.03 events per patient-year. Outflow graft obstruction presented a median of 33 (26-49) months after surgery. Patients presented with low estimated LVAD pump flow (95%), heart failure (90%), or both (85%), and 59% developed cardiogenic shock prior to intervention. The most common aetiology identified by cardiac computed tomography with angiography was external compression of the outflow graft (78%). On presentation, the median peak gradient in the outflow graft was 78 (64-100) mmHg. Outflow graft stenting was 100% successful with no in-hospital mortality, and it reduced the peak outflow graft gradient to 10 (2-17) mmHg (P < 0.001). Outflow graft stenting was durable with two patients (10%) requiring a repeat procedure over a median follow-up of 13 (7-20) months and did not impact survival. CONCLUSIONS: Left ventricular assist device outflow graft obstruction is a relatively common and underappreciated cause of recurrent heart failure and LVAD dysfunction. Outflow graft stenting can be achieved with low morbidity and provides a long-term solution to this complication.

Sex differences in eligibility for advanced heart failure therapies.

OBJECTIVES: We investigated sex-based differences in eligibility for and outcomes after receipt of advanced heart failure (HF) therapies. BACKGROUND: Although women are more likely to die from HF than men, registry data suggest that women are less likely to receive heart transplant (HT) or left ventricular assist device (LVAD) for largely unknown reasons. METHODS: We performed a single-center retrospective cohort study of patients evaluated for advanced HF therapies from 2012 to 2016. Logistic regression was used to determine the association of sex with eligibility for HT/LVAD. Competing risks and Kaplan-Meier analysis were used to examine survival. RESULTS: Of 569 patients (31% women) evaluated, 223 (39.2%) were listed for HT and 81 (14.2%) received destination (DT) LVAD. Women were less likely to be listed for HT (adjusted odds ratio [OR] 0.36, 95% confidence interval [CI] 0.21-0.61; P < .0001), based on allosensitization (P < .0001) and obesity (P = .02). Women were more likely to receive DT LVAD (adjusted OR 2.29, 95% CI 1.23-4.29; P = .01). Survival was similar between men and women regardless of whether they received HT and DT LVAD or were ineligible for therapy. CONCLUSION: Women are less likely to be HT candidates, but more likely to receive DT LVAD.

Validating patient prioritization in the 2018 Revised United Network for Organ Sharing Heart Allocation System: A single-center experience.

The 2018 Revised United Network for Organ Sharing Heart Allocation System (HAS) was proposed to reclassify status 1A candidates into groups of decreasing acuity; however, it does not take into account factors such as body mass index (BMI) and blood group which influence waitlist (WL) outcomes. We sought to validate patient prioritization in the new HAS at our center. We retrospectively evaluated patients listed for heart transplantation (n = 214) at Emory University Hospital from 2011 to 2017. Patients were reclassified into the 6-tier HAS. Multistate modeling and competing risk analysis were used to compare outcomes of transplantation and WL death/deterioration between new tiers. Additionally, a stratified sensitivity analysis by BMI and blood group was performed. Compared with tier 4 patients, there was progressively increasing hazard of WL death/deterioration in tier 3 (HR: 2.52, 95% CI: 1.37-4.63, P = .003) and tier 2 (HR: 5.03, 95% CI: 1.99-12.70, P < .001), without a difference in transplantation outcome. When stratified by BMI and blood group, this hierarchical association was not valid in patients with BMI ≥30 kg/m2 and non-O blood groups in our cohort. Therefore, the 2018 HAS accurately prioritizes the sickest patients in our cohort. Factors such as BMI and blood group influence this relationship and iterate that the system can be further refined.

Decisional regret in left ventricular assist device patient-caregiver dyads.

BACKGROUND: The objective of this study was to investigate decisional regret among left ventricular assist device (LVAD) patients and their caregivers. METHODS: This study was a single center, cross-sectional survey of patients after LVAD implantation and their caregivers. Subjects were recruited at their outpatient heart failure appointments. Patients and caregivers at least three months from LVAD implantation completed a 5-item, validated decisional regret scale. Summative scores on a 0-100 point scale were determined for patient and caregivers (0 = no regret). Subgroup analysis included gender, LVAD indication (bridge to transplant (BTT) or destination therapy (DT)), time from LVAD implantation, and caregiver relationship. Dyad discordance was defined as a patient-caregiver difference of ≥2 points on any regret scale question. RESULTS: Fifty patients were approached for participation. Thirty-three LVAD patient-caregiver dyads were enrolled in the study (19 male, 14 female patients; 8 male, 25 female caregivers). Patients had a mean age of approximately 50 years. Caregivers had a mean age of approximately 54 years. Patients had a median regret score of 10 (Interquartile range (IQR): 0-30), while caregivers had a median regret score of 20 (IQR: 0-25). Median regret scores of female patients were significantly higher than that of male patients (27.5 vs 0, p = 0.0038). BTT patients had numerically lower regret than DT patients, but this was not statistically significant. Patients who had been implanted for greater than three years had the highest regret scores. Discordance in at least one domain of the regret scale was present in 19 out of 33 (57.6%) dyads. CONCLUSIONS: While decisional regret was reasonably low in this population, comparatively, there was significantly increased decisional regret among female patients and patients further from LVAD implantation. Differences between patients and caregivers were also observed. These findings highlight the need for robust support and continual attention to expectations before and after LVAD implantation.

Mortality in status 2 patients listed for heart transplantation in the United States: Will understanding cause of death help justify implantation of left ventricular assist devices into less sick patients?

OBJECTIVE: It remains unclear whether left ventricular assist device (LVAD) implantation in non-inotrope dependent patients is of clinical benefit. This study sought to evaluate cause of death in patients listed for heart transplant (HT) to determine the relative risks and benefits of implanting LVAD into patients who are less sick than those included in the original clinical trials. METHODS: We examined death as the primary outcome in 23,098 patients listed for HT from 2006 to 2014 using proportional subdistribution hazards modeling. Cause of death was examined as a secondary outcome using χ2 tests. RESULTS: 1859 (8.1%) patients were removed from the wait list for death, including 229 (2.7%) status 1A, 349 (4.6%) status 1B, 246 (13.2%) status 2, and 1035 (26.0%) status 7 patients (P < 0.0001). Status 2 patients who received LVAD while listed had a higher risk of death compared to those who did not (adjusted HR 1.68; 95% CI 1.09-2.59; P = 0.02), while there was no increased risk of death in status 1A (HR 1.02; 95% CI 0.68-1.51; P = 0.9) and status 1B (HR 0.89; 95% CI 0.65-1.23; P = 0.5) who received LVAD. Status 2 patients who received LVAD were more likely to die cerebrovascular causes (0.6% vs. 0.1%, P = 0.009) and organ failure (70.6% vs. 29.4%, P = 0.003). CONCLUSIONS: LVAD implantation in status 2 patients listed for HT is associated with a higher risk of death. More research is needed to determine the impact LVAD implantation will have on mortality in patients with ambulatory, non-inotrope dependent HF.

Impact of insurance type on eligibility for advanced heart failure therapies and survival.

BACKGROUND: Medicaid insurance in Georgia provides limited reimbursement for heart transplant (HT) and left ventricular assist devices (LVAD). We examined whether insurance type affects eligibility for and survival after receipt of HT or LVAD. METHODS AND RESULTS: We retrospectively identified patients evaluated for HT/LVAD from 2012 to 2016. We used multivariable logistic and Cox proportional hazards regression to examine the association of insurance type on treatment eligibility and 1-year survival. Of 569 patients evaluated, 282 (49.6%) had private, 222 (39.0%) had Medicare, and 65 (11.4%) had Medicaid insurance. Patients with Medicaid were younger, more likely to be Black, with fewer medical comorbidities. In adjusted models, Medicare and Medicaid insurance predicted lower odds of eligibility for HT, but did not affect survival after HT. Among those ineligible for HT, Medicaid patients were less likely to receive destination therapy (DT) LVAD (adj OR 0.08, 95% CI 0.01-0.66; P = .02) and had increased risk of death (adj HR = 2.03, 95% CI 1.13-3.63; P = .01). CONCLUSIONS: Despite younger age and fewer comorbidities, patients with Medicaid insurance are less likely to receive DT LVAD and have an increased risk of death once deemed ineligible for HT. Medicaid patients in Georgia need improved access to DT LVAD.

Racial differences in the development of de-novo donor-specific antibodies and treated antibody-mediated rejection after heart transplantation.

BACKGROUND: Despite improvements in outcomes after heart transplantation, black recipients have worse survival compared with non-black recipients. The source of such disparate outcomes remains largely unknown. We hypothesize that a propensity to generate de-novo donor-specific antibodies (dnDSA) and subsequent antibody-mediated rejection (AMR) may account for racial differences in sub-optimal outcomes after heart transplant. In this study we aimed to determine the role of dnDSA and AMR in racial disparities in post-transplant outcomes. METHODS: This study was a single-center, retrospective analysis of 137 heart transplant recipients (81% male, 48% black) discharged from Emory University Hospital. Patients were classified as black vs non-black for the purpose of our analysis. Kaplan-Meier and Cox regression analyses were used to evaluate the association between race and selected outcomes. The primary outcome was the development of dnDSA. Secondary outcomes included treated AMR and a composite of all-cause graft dysfunction or death. RESULTS: After 3.7 years of follow-up, 39 (28.5%) patients developed dnDSA and 19 (13.8%) were treated for AMR. In multivariable models, black race was associated with a higher risk of developing dnDSA (hazard ratio [HR] 3.65, 95% confidence interval [CI] 1.54 to 8.65, p = 0.003) and a higher risk of treated AMR (HR 4.86, 95% CI 1.26 to 18.72, p = 0.021) compared with non-black race. Black race was also associated with a higher risk of all-cause graft dysfunction or death in univariate analyses (HR 2.10, 95% CI 1.02 to 4.30, p = 0.044). However, in a multivariable model incorporating dnDSA, black race was no longer a significant risk factor. Only dnDSA development was significantly associated with all-cause graft dysfunction or death (HR 4.85, 95% CI 1.89 to 12.44, p = 0.001). CONCLUSION: Black transplant recipients are at higher risk for the development of dnDSA and treated AMR, which may account for racial disparities in outcomes after heart transplantation.

De novo DQ donor-specific antibodies are associated with worse outcomes compared to non-DQ de novo donor-specific antibodies following heart transplantation.

BACKGROUND: Antibody-mediated rejection (AMR) resulting from de novo donor-specific antibodies (dnDSA) leads to adverse outcomes following heart transplantation (HTx). It remains unclear what role dnDSA to specific HLA antigens play in adverse outcomes. This study compares outcomes in patients developing dnDSA to DQ antigens with those developing non-DQ dnDSA and those free from dnDSA. METHODS: The present study was a single-center, retrospective analysis of 122 consecutive HTx recipients. The primary outcome was a composite of death or graft dysfunction. RESULTS: After 3.3 years of follow-up, 31 (28%) patients developed dnDSA. Mean time to dnDSA was 539 days. Of 31 patients, 19 developed DQ antibodies and 12 developed non-DQ antibodies. Compared to non-DQ dnDSA, DQ antibodies presented with higher MFI values (P=.001) were more likely persistent (P=.001) and appeared later post-HTx (654 vs 359 days, P=.035). In a multivariable analysis, DQ dnDSA was associated with increased risk of the primary endpoint (HR 6.15, 95% CI 2.57-14.75, P=.001), whereas no increased risk was seen with non-DQ dnDSA (P=.749). CONCLUSIONS: dnDSA to DQ antigens following HTx are associated with increased risk of death and graft dysfunction.

The Right Ventricular Function After Left Ventricular Assist Device (RVF-LVAD) study: rationale and preliminary results.

AIMS: Despite improved outcomes and lower right ventricular failure (RVF) rates with continuous-flow left ventricular assist devices (LVADs), RVF still occurs in 20-40% of LVAD recipients and leads to worse clinical and patient-centred outcomes and higher utilization of healthcare resources. Preoperative quantification of RV function with echocardiography has only recently been considered for RVF prediction, and RV mechanics have not been prospectively evaluated. METHODS AND RESULTS: In this single-centre prospective cohort study, we plan to enroll a total of 120 LVAD candidates to evaluate standard and mechanics-based echocardiographic measures of RV function, obtained within 7 days of planned LVAD surgery, for prediction of (i) RVF within 90 days; (ii) quality of life (QoL) at 90 days; and (iii) RV function recovery at 90 days post-LVAD. Our primary hypothesis is that an RV echocardiographic score will predict RVF with clinically relevant discrimination (C >0.85) and positive and negative predictive values (>80%). Our secondary hypothesis is that the RV score will predict QoL and RV recovery by 90 days. We expect that RV mechanics will provide incremental prognostic information for these outcomes. The preliminary results of an interim analysis are encouraging. CONCLUSION: The results of this study may help improve LVAD outcomes and reduce resource utilization by facilitating shared decision-making and selection for LVAD implantation, provide insights into RV function recovery, and potentially inform reassessment of LVAD timing in patients at high risk for RVF.

Multidrug-Resistant Organism Infections in Patients with Left Ventricular Assist Devices.

Left ventricular assist devices improve survival prospects in patients with end-stage heart failure; however, infection complicates up to 59% of implantation cases. How many of these infections are caused by multidrug-resistant organisms is unknown. We sought to identify the incidence, risk factors, and outcomes of multidrug-resistant organism infection in patients who have left ventricular assist devices. We retrospectively evaluated the incidence of multidrug-resistant organisms and the independent risk factors associated with them in 57 patients who had permanent left ventricular assist devices implanted at our institution from May 2007 through October 2011. Outcomes included death, transplantation, device explantation, number of subsequent hospital admissions, and number of subsequent admissions related to infection. Infections were categorized in accordance with criteria from the Infectious Diseases Council of the International Society for Heart and Lung Transplantation. Multidrug-resistant organism infections developed in 18 of 57 patients (31.6%)-a high incidence. We found 3 independent risk factors: therapeutic goal (destination therapy vs bridging), P=0.01; body mass index, P=0.04; and exposed velour at driveline exit sites, P=0.004. We found no significant differences in mortality, transplantation, or device explantation rates; however, there was a statistically significant increase in postimplantation hospital admissions in patients with multidrug-resistant organism infection. To our knowledge, this is the first report in the medical literature concerning multidrug-resistant organism infection in patients who have permanent left ventricular assist devices.

Gender differences in the risk of stroke during support with continuous-flow left ventricular assist device.

BACKGROUND: There is increasing recognition that the risk of stroke after left ventricular assist device (LVAD) implantation varies based on gender, with a higher risk in female patients. We reviewed our own data to determine gender differences in the risk of stroke. METHODS: Frequency of stroke, including intracranial hemorrhage and ischemic stroke, was retrospectively evaluated in 110 heart failure patients (mean age 49.6 ± 13.6 years, 32% women) discharged from the hospital after implantation of a HeartMate II (N = 74) or HeartWare (N = 36) LVAD. Competing outcomes analysis was used to determine which clinical risk factors were associated with the risk of stroke and death, with the primary end-point being time to first stroke event. RESULTS: During a median follow-up of 1.3 years, 26 patients had a stroke (23.6%, 0.14 case per person-year). The median time to first stroke was 0.7 (interquartile range 0.3 to 1.4) years. After adjusting for covariates, risk of stroke was higher for women than for men (hazard ratio 3.1, 95% confidence interval 1.4 to 6.9; p = 0.007). There was no difference in overall survival between men and women. CONCLUSION: The risk of stroke after LVAD varies based on gender, with a higher risk in female patients. More research is needed to fully understand these differences, and whether device management strategies should be tailored based on gender.

Validation of clinical scores for right ventricular failure prediction after implantation of continuous-flow left ventricular assist devices.

BACKGROUND: Several clinical prediction schemes for right ventricular failure (RVF) risk after left ventricular assist device (LVAD) implantation have been developed in both the pulsatile- and continuous-flow LVAD eras. The performance of these models has not been evaluated systematically in a continuous-flow LVAD cohort. METHODS: We evaluated 6 clinical RVF prediction models (Michigan, Penn, Utah, Kormos et al, CRITT, Pittsburgh Decision Tree) in 116 patients (age 51 ± 13 years; 41.4% white and 56.0% black; 66.4% men; 56.0% bridge to transplant, 37.1% destination therapy, 17.4% bridge to decision) who received a continuous-flow LVAD (HeartMate II: 79 patients, HeartWare: 37 patients) between 2008 and 2013. RESULTS: Overall, 37 patients (31.9%) developed RVF, defined: as pulmonary vasodilator use for ≥48 hours or inotrope use for ≥14 days post-operatively; re-institution of inotropes; multi-organ failure due to RVF; or need for mechanical RV support. Median (Quartile 1 to Quartile 3) time to initial discontinuation of inotropes was 6 (range 4 to 8) days. Among scores, the Michigan score reached significance for RVF prediction but discrimination was modest (C = 0.62 [95% CI 0.52 to 0.72], p = 0.021; positive predictive value [PPV] 60.0%; negative predictive value [NPV] 75.8%), followed by CRITT (C = 0.60 [95% CI 0.50 to 0.71], p = 0.059; PPV 40.5%; NPV 72.2%). Other models did not significantly discriminate RVF. The newer, INTERMACS 3.0 definition for RVF, which includes inotropic support beyond 7 days, was reached by 57 patients (49.1%). The Kormos model performed best with this definition (C = 0.62 [95% CI 0.54 to 0.71], p = 0.005; PPV 64.3%; NPV 59.5%), followed by Penn (C = 0.61), Michigan (C = 0.60) and CRITT (C = 0.60), but overall score performance was modest. CONCLUSION: Current schemes for post-LVAD RVF risk prediction perform only modestly when applied to external populations.

Improved Outcomes for Women on the Heart Transplant Wait List in the Modern Era.

BACKGROUND: Whether the routine use of continuous-flow left ventricular assist devices (LVAD) has affected gender differences in outcomes for patients listed for heart transplantation (HT) is unclear. METHODS AND RESULTS: We identified 20,468 adults (25% women) listed as status 1A or 1B for HT from 2000 to 2014. Sex differences in removal from the wait list during the first 365 days due to death or deterioration was assessed with the use of Kaplan-Meier survival analysis. Patients were stratified according to listing before (era 1) or after (era 2) Food and Drug Administration approval of the Heartmate II LVAD on April 22, 2008. Freedom from death or deterioration on the wait list was higher for men than for women (70% vs 64%; P < .001). After adjusting for risk factors, women had a higher risk of removal from the wait list at 365 days during both era 1 (hazard ratio [HR] 1.23, 95% confidence interval [CI] 1.10-1.36; P < .001) and era 2 (HR 1.15, 95% CI 1.01-1.31; P = .029). Further adjustment for LVAD use eliminated the higher risk for women in era 2 (HR 1.14, 95% CI 0.99-1.29; P = .053) and not in era 1 (HR 1.22, 95% CI 1.10-1.36; P < .001). CONCLUSIONS: The higher risk for death or deterioration in women waiting for HT has improved in the modern era.