Status 2 upgrade indication impacts posttransplant mortality in patients bridged with intraaortic balloon pump in the new heart allocation system

To evaluate outcomes of patients undergoing heart transplants (HTs) using an intra-aortic balloon pump (IABP) under exception status. Adult patients supported by an IABP who underwent HT between November 18, 2018, and December 31, 2020, as documented in the United Network for Organ Sharing, were included. Patients were stratified according to requests for exception status. Kaplan-Meier methodology was used to look for differences in survival between groups. A total of 1284 patients were included; 492 (38.3%) were transplanted with an IABP under exception status. Exception status patients had higher body mass index, were more likely to be Black, and had longer waitlist times. Exception status patients received organs from younger donors, had a shorter ischemic time, and had a higher frequency of sex mismatch. The 1-year posttransplant survival was 93% for the nonexception and 88% for the exception IABP patients (hazard ratio: 1.85 [95% confidence interval: 1.12-2.86, P = .006]). The most common reason for requesting an exception status was inability to meet blood pressure criteria for extension (37% of patients). The most common reason for an extension request for an exception status was right ventricular dysfunction (24%). IABP patients transplanted under exception status have an increased 1-year mortality rate posttransplant compared with those without exception status.

Extracorporeal membrane oxygenation as a bridge to advanced heart failure therapies

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) is a key support modality for cardiogenic shock. The 2018 United Network for Organ Sharing (UNOS) heart transplant allocation algorithm prioritizes VA-ECMO patients.

OBJECTIVE

To evaluate the role of VA-ECMO in bridging to advanced heart failure therapies.

METHODS

We analyzed adult patients from the multicenter Extracorporeal Life Support Organization registry receiving VA-ECMO for cardiac support or resuscitation between 2016 and 2021 in the United States, comparing bridge-to-transplant (BTT) and non-BTT intent patients, as well as pre- vs post-2018 patients, on a wide range of demographic and clinical outcome predictors.

RESULTS

Of 17,087 patients, 797 received left ventricular assist device (LVAD)/heart transplant, 7,931 died or had poor prognosis, and 8,359 had expected recovery at ECMO discontinuation. Patients supported with BTT intent had lower clinical acuity than non-BTT candidates and were more likely to receive LVAD/transplant. The proportion of patients who received VA-ECMO as BTT and received LVAD/transplant increased after 2018. Post-2018 BTT patients had significantly lower clinical acuity and higher likelihood of transplant than both post-2018 non-BTT patients and pre-2018 BTT patients. ECMO complications were associated with lower likelihood of transplant but were significantly less common post-2018 than pre-2018.

CONCLUSIONS

After implementation of the 2018 UNOS allocation system, ECMO utilization as BTT or LVAD has increased, and the acuity of BTT intent patients cannulated for ECMO has decreased. There has not yet been an increase in more acute ECMO patients getting transplanted. This may partially explain the post-transplant outcomes of ECMO patients in the current era reported in UNOS.

Aortic valve disorders and left ventricular assist devices

Aortic valve disorders are important considerations in advanced heart failure patients being evaluated for left ventricular assist devices (LVAD) and those on LVAD support. Aortic insufficiency (AI) can be present prior to LVAD implantation or develop de novo during LVAD support. It is usually a progressive disorder and can lead to impaired LVAD effectiveness and heart failure symptoms. Severe AI is associated with worsening hemodynamics, increased hospitalizations, and decreased survival in LVAD patients. Diagnosis is made with echocardiographic, device assessment, and/or catheterization studies. Standard echocardiographic criteria for AI are insufficient for accurate diagnosis of AI severity. Management of pre-existing AI includes aortic repair or replacement at the time of LVAD implant. Management of de novo AI on LVAD support is challenging with increased risks of repeat surgical intervention, and percutaneous techniques including transcatheter aortic valve replacement are assuming greater importance. In this manuscript, we provide a comprehensive approach to contemporary diagnosis and management of aortic valve disorders in the setting of LVAD therapy.

Risk of Developing Acute Kidney Injury on the VA ECLS Circuit in Patients with Acute Decompensated Heart Failure

Aims Venoarterial extracorporeal life support (VA ECLS) is a life-saving treatment with a high risk of mortality. Appropriate patient selection is critical for optimal patient outcomes. Acute kidney injury (AKI) is a common risk among VA ECLS patients, and more information is needed to understand how AKI affects the mortality risk of these patients. To do this, we examined acute decompensated heart failure (ADHF) patients supported by VA ECLS and compared their risk of developing AKI to a background population. VA ECLS has become an increasingly important tool to bridge or recover patients with severe ADHF as the primary indication of VA ECLS.

Methods and Results All VA ECLS patients from a single center were included. ADHF patients supported by VA ECLS were compared with the remaining VA ECLS cohort. CATEGORICAL comparisons were made between groups using chi-squared and Fisher's exact tests. A survival analysis was conducted to determine freedom from AKI between the two groups. Predictor variables were tested by multiple logistic regression. Of the 255 patients included in this study, 110 had ADHF as their primary indication for VA ECLS and 145 patients had other VA ECLS indications. The survival analysis showed that patients with ADHF had a decreased risk of developing AKI on the VA ECLS circuit. Multiple logistic regression revealed no predictors in AKI development between groups and no difference in 30-day mortality was observed.

Conclusion Patients supported by VA ECLS are at high risk of mortality and complications. This research demonstrated that medically complex ADHF patients had less chance of developing AKI when compared with other patients supported by VA ECLS. Future research is needed to investigate potential protective mechanisms of VA ECLS support.

Have risk factors for mortality after heart transplantation changed over time? Insights from 19 years of Cardiac Transplant Research Database study

BACKGROUND

The Cardiac Transplant Research Database (CTRD) collected data from 26 U.S. institutions from January 1, 1990 to December 31, 2008 providing the opportunity for construction of a comprehensive multivariable model of risk for death after transplantation. We analyzed risk factors for death over 19 years of experience to determine how risk profiles have changed over time and how they interact with age.

METHODS

A multivariable parametric hazard model for death was created for 7,015 patients entered into the CTRD. Variables collected over 19 years of experience were examined as potential risk factors and tested for interaction with date of transplantation to determine if their relative risk (RR) changed over time.

RESULTS

The hazard for death post-transplant occurred in 2 phases: an early phase of acute risk lasting <1 year, and a late phase of relatively low, gradually increasing risk (<0.1 event/year). In the early phase, predictive models showed that ventricular assist device (VAD) at the time of transplant did not increase the RR of death for recipient transplant at 30 years of age, but the RR of death was increased by 60% (p = 0.04) at 60 years of age. Of the late-phase variables found to be risk factors, the RR of age, date of transplant and pulmonary vascular resistance changed with respect to transplant year. The overall risk of death dropped importantly over the study period, but the RR of all other variables remained unchanged. RR was 2.6 (p < 0.0001) for 25-year-old African-American (AA) versus non-AA recipients and 1.6 for 60-year-old AA recipients (p = 0.02).

CONCLUSION

Over 19 years, the baseline risk of death has decreased, but the specific risk factors and the magnitudes of their RR have remained unchanged. Therefore, despite advances in clinical management and improvement in overall survival, the risk profile for death after cardiac transplantation is similar to that in 1990.