Donor Heart Allocation

The limited number of donor hearts is one of the greatest and persistent challenges to heart transplantation. Allocation of this precious resource requires the integration of objective data, clinical intuition, and moral fairness. Institution of an allocation system by UNOS has provided important structure to the allocation methodology. The system must be periodically reviewed and reorganized to ensure it is reflective of current patient disease and clinical practice and builds upon the previous knowledge paradigms. Since the establishment of the 2006 allocation system, not only has there been a dramatic increase in the number of heart transplant candidates, but also a dramatic increase in the number of patients qualifying as high-priority candidates. To address these changes, UNOS Thoracic Organ Transplantation Committee was tasked with providing a revised allocation system. The resulting system aims to improve waitlist mortality and post-transplant outcomes by better prioritizing the highest acuity patients while improving the geographic distribution of organ offers

The Effect of Extremity Vascular Complications on the Outcomes of Cardiac Support Device Recipients

ObjectiveTo assess the effect of extremity vascular complications (EVCs, including ischemia or vessel trauma) on the outcomes of patients receiving cardiac support devices (CSDs, including ventricular assist device [VAD] and extracorporeal membrane oxygenation [ECMO]).MethodsInstitutional Review Board-approved, retrospective review of a prospectively maintained database of all temporary and permanent CSD recipients from 7/1/10 to 6/30/12. Patient demographics, procedural data, and outcomes were analyzed. The primary endpoint was all-cause mortality at 30-days post-CSD initiation.ResultsOf 208 patients who received CSDs, 31 (14.9%) experienced EVC: 13 (8.9%) of the 146 permanent VADs, 10 (26.3%) of the 38 temporary VADs, and 8 (33.3%) of the 24 ECMO patients. The 30-day mortality for CSD-EVC patients was not significantly higher than that of the CSD patients who did not experience EVC for permanent VAD (15.4% vs 4.5%; P = .15) and ECMO patients (50.0% vs 68.75%; P = 1.00), but was significantly higher for temporary VAD patients (80.0% vs 35.7%; P = .03). Within the CSD-EVC cohort, patients who received a temporary VAD had a significantly higher 30-day mortality and decision to withdraw care after EVC compared with those who received a permanent VAD (P = .01 and P < .01, respectively). Looking beyond the 30-day window, EVC was associated with higher mortality rates in the permanent VAD population (53.8% vs 25.6%; P = .025) but not the temporary VAD or ECMO groups.ConclusionsIn temporary VAD recipients, EVCs result in higher 30-day mortality, more frequent withdrawal of care, and shortened survival time relative to the global temporary VAD group. EVC in permanent VAD recipients did not affect early (30-day) mortality rates, but strongly predicted a higher cumulative mortality risk for the 2-year study period. Overall ECMO mortality rates were high, and not significantly impacted by the occurrence of EVC. The nature of the EVC (cannulation site complication vs embolic injury) did not impact mortality. This data provides quality improvement targets for VAD programs

What If the Destination Is Transplant? Outcomes of Destination Therapy Patients Who Were Transplanted

We sought to characterize patients who underwent heart transplant (HTx) following destination therapy (DT) implant in the combined ENDURANCE/ENDURANCE Supplemental Trials (DT/DT2). A post hoc analysis of the DT/DT2 trials was performed. Baseline characteristics and adverse events between the HTx and no-HTx cohorts were analyzed. Reasons for transplant were examined. Time to HTx was compared with contemporaneous HVAD BTT trial patients. Of the 604 DT/DT2 HVAD patients, 80 (13%) underwent HTx. The HTx cohort was younger (53.6 ± 11.1 vs. 65.2 ± 10.8, P \u3c 0.0001) with fewer Caucasians (60.0% vs. 76.5%, P = 0.002), less ischemic cardiomyopathy (42.5% vs. 58.8%, P = 0.01), and atrial fibrillation (38.8% vs. 54.4%, P = 0.01). The HTx cohort had longer 6-minute walk distances (183.6 vs. 38.0 m, P = 0.02). Most HTx in DT/DT2 were categorized as elective (n = 63, 79%) and, of these, 70% were due to modification of behavioral issues and weight loss. Adverse events were the main indication for urgent HTx (n = 17, 21%). Median times to HTx were longer in DT/DT2 (550.0 days) versus BTT/lateral (285.2 days). In this post hoc analysis of the DT/DT2 trials, over 1 in 10 underwent heart transplantation within 3 years of HVAD support. In DT therapy patients, consideration for transplant following DT VAD implant may be feasible

Evaluation of Latex Immunoturbidimetric Assay Thresholds and HIT in Cardiothoracic Surgery

Background Heparin-induced thrombocytopenia (HIT) is a common differential diagnosis in cardiothoracic surgery. The latex immunoturbidimetric assay (LIA) is an enhanced immunoassay that has recently been introduced for the detection of total HIT immunoglobulin and retains a higher specificity of 95% compared to the enzyme-linked immunosorbent assay. Objectives To investigate if a semiquantitative relationship exists between increasing LIA levels beyond the current positivity threshold and its correlation to positive serotonin release assay results in cardiothoracic surgery. Methods This was a multicenter, observational cohort of cardiothoracic surgery patients initiated on anticoagulation with heparin-based products. To conduct sensitivity and specificity analysis of LIA values, HIT positive was defined as a LIA value ≥1 unit/mL and HIT negative was defined as a LIA level <1 unit/mL. A receiver operating characteristic (ROC) analysis was utilized to evaluate the predictive performance of the LIA. Results At manufactures’ cutoffs of ≥1.0 unit/mL, LIA sensitivity and specificity was 93.8% and 22%, respectively, yielding a false positive rate of 78%. At a higher cutoff of 4.5 units/mL, LIA sensitivity and specificity was 75% and 71%, respectively, yielding a false positive rate of 29% and an area under the ROC curve of 0.75 (P = .01; 95% confidence interval: 0.621-0.889). Bivalirudin was initiated in 84.6% of false positive LIA results. Conclusion This study suggests that the diagnostic accuracy of the LIA can be optimized by increasing the LIA positivity threshold. Proposing a higher LIA cutoff, may mitigate unwarranted anticoagulation and bleeding outcomes

Slope of the anterior mitral valve leaflet: A new measurement of left ventricular unloading for left ventricular assist devices and systolic dysfunction

Left ventricular assist device (LVAD)-supported patients are evaluated routinely with use of transthoracic echocardiography. Values of left ventricular unloading in this unique patient population are needed to evaluate LVAD function and assist in patient follow-up. We introduce a new M-mode measurement, the slope of the anterior mitral valve leaflet (SLAM), and compare its efficacy with that of other standard echocardiographically evaluated values for left ventricular loading, including E/e′ and pulmonary artery systolic pressures. Average SLAM values were determined retrospectively for cohorts of random, non-LVAD patients with moderately to severely impaired left ventricular ejection fraction (LVEF) (<0.35, n=60). In addition, pre- and post-LVAD implantation echocardiographic images of 81 patients were reviewed. The average SLAM in patients with an LVEF <0.35 was 11.6 cm/s (95% confidence interval, 10.4–12.8); SLAM had a moderately strong correlation with E/e′ in these patients. Implantation of LVADs significantly increased the SLAM from 7.3 ± 2.44 to 14.7 ± 5.01 cm/s (n=42, P <0.0001). The LVAD-supported patients readmitted for exacerbation of congestive heart failure exhibited decreased SLAM from 12 ± 3.93 to 7.3 ± 3.5 cm/s (n=6, P=0.041). In addition, a cutpoint of 10 cm/s distinguished random patients with LVEF <0.35 from those in end-stage congestive heart failure (pre-LVAD) with an 88% sensitivity and a 55% specificity. Evaluating ventricular unloading in LVAD patients remains challenging. Our novel M-mode value correlates with echocardiographic values of left ventricular filling in patients with moderate-to-severe systolic function and dynamically improves with the ventricular unloading of an LVAD

One-year outcomes after transcatheter insertion of an interatrial shunt device for the management of heart failure with preserved ejection fraction

Background—Heart failure with preserved ejection fraction has a complex pathophysiology and remains a therapeutic challenge. Elevated left atrial pressure, particularly during exercise, is a key contributor to morbidity and mortality. Preliminary analyses have demonstrated that a novel interatrial septal shunt device that allows shunting to reduce the left atrial pressure provides clinical and hemodynamic benefit at 6 months. Given the chronicity of heart failure with preserved ejection fraction, evidence of longer-term benefit is required. Methods and Results—Patients (n=64) with left ventricular ejection fraction ≥40%, New York Heart Association class II–IV, elevated pulmonary capillary wedge pressure (≥15 mm Hg at rest or ≥25 mm Hg during supine bicycle exercise) participated in the open-label study of the interatrial septal shunt device. One year after interatrial septal shunt device implantation, there were sustained improvements in New York Heart Association class (P&lt;0.001), quality of life (Minnesota Living with Heart Failure score, P&lt;0.001), and 6-minute walk distance (P&lt;0.01). Echocardiography showed a small, stable reduction in left ventricular end-diastolic volume index (P&lt;0.001), with a concomitant small stable increase in the right ventricular end-diastolic volume index (P&lt;0.001). Invasive hemodynamic studies performed in a subset of patients demonstrated a sustained reduction in the workload corrected exercise pulmonary capillary wedge pressure (P&lt;0.01). Survival at 1 year was 95%, and there was no evidence of device-related complications. Conclusions—These results provide evidence of safety and sustained clinical benefit in heart failure with preserved ejection fraction patients 1 year after interatrial septal shunt device implantation. Randomized, blinded studies are underway to confirm these observations

Clinical outcomes and healthcare expenditures in the real world with left ventricular assist devices - The CLEAR-LVAD study

BACKGROUND: Several distinctly engineered left ventricular assist devices (LVADs) are in clinical use. However, contemporaneous real world comparisons have not been conducted, and clinical trials were not powered to evaluate differential survival outcomes across devices. OBJECTIVES: Determine real world survival outcomes and healthcare expenditures for commercially available durable LVADs. METHODS: Using a retrospective observational cohort design, Medicare claims files were linked to manufacturer device registration data to identify de-novo, durable LVAD implants performed between January 2014 and December 2018, with follow-up through December 2019. Survival outcomes were compared using a Cox proportional hazards model stratified by LVAD type and validated using propensity score matching. Healthcare resource utilization was analyzed across device types by using nonparametric bootstrap analysis methodology. Primary outcome was survival at 1-year and total Part A Medicare payments. RESULTS: A total of 4,195 de-novo LVAD implants were identified in fee-for-service Medicare beneficiaries (821 HeartMate 3; 1,840 HeartMate II; and 1,534 Other-VADs). The adjusted hazard ratio for mortality at 1-year (confirmed in a propensity score matched analysis) for the HeartMate 3 vs HeartMate II was 0.64 (95% CI; 0.52-0.79, p\u3c 0.001) and for the HeartMate 3 vs Other-VADs was 0.51 (95% CI; 0.42-0.63, p \u3c 0.001). The HeartMate 3 cohort experienced fewer hospitalizations per patient-year vs Other-VADs (respectively, 2.8 vs 3.2 EPPY hospitalizations, p \u3c 0.01) and 6.1 fewer hospital days on average (respectively, 25.2 vs 31.3 days, p \u3c 0.01). The difference in Medicare expenditures, conditional on survival, for HeartMate 3 vs HeartMate II was -$10,722, p \u3c 0.001 (17.4$17,947, p \u3c 0.001 (26.1% reduction). CONCLUSIONS: In this analysis of a large, real world, United States. administrative dataset of durable LVADs, we observed that the HeartMate 3 had superior survival, reduced healthcare resource use, and lower healthcare expenditure compared to other contemporary commercially available LVADs

Interpreting neurologic outcomes in a changing trial design landscape: An analysis of HeartWare left ventricular assist device using a hybrid intention to treat population

Randomized controlled trials can provide optimal clinical evidence to assess the benefits of new devices, and it is these data that often shape device usage in real-world practice. However, individual clinical trial results sometimes appear discordant for the same device, and alternative devices are sometimes not employed in similar patient populations. To make sound evidence-based decisions, clinicians routinely rely on cross-trial comparisons from different trials of similar but not identical patient populations to assess competing technology when head-to-head randomized comparisons are unavailable