Twenty-Year Experience of Heart Transplantation: Early and Long-Term Results

Mechanical ventilation at the time of heart transplantation and associations with clinical outcomes

AIMS

The impact of mechanical ventilation (MV) at the time of heart transplantation is not well understood. In addition, MV was recently removed as a criterion from the new US heart transplantation allocation system. We sought to assess for the association between MV at transplantation and 1-year mortality.

METHODS AND RESULTS

We utilized the United Network for Organ Sharing database and included all adult, single organ heart transplantations from 1990 to 2019. We utilized multivariable logistic regression adjusting for demographics, comorbidities, and markers of clinical acuity. We identified 60 980 patients who underwent heart transplantation, 2.4% (n = 1431) of which required MV at transplantation. Ventilated patients were more likely to require temporary mechanical support, previous dialysis, and had a shorter median waitlist time (21 vs. 95 days, P < 0.001). At 1 year, the mortality was 33.7% (n = 484) for ventilated patients and 11.7% (n = 6967) for those not ventilated at the time of transplantation (log-rank P < 0.001). After multivariable adjustment, patients requiring MV continued to have a substantially higher 90-day [odds ratio (OR) 3.20, 95% confidence interval (CI): 2.79-3.66, P < 0.001] and 1-year mortality (OR 2.67, 95% CI: 2.36-3.03, P < 0.001). For those that survived to 90 days, the adjusted mortality at 1 year continued to be higher (OR 1.48, 95% CI: 1.16-1.89, P = 0.002).

CONCLUSION

We found a strong association between the presence of MV at heart transplantation and 90-day and 1-year mortality. Future studies are needed to identify which patients requiring MV have reasonable outcomes, and which are associated with substantially poorer outcomes.

Acute Kidney Injury in Patients Undergoing Cardiac Transplantation: A Meta-Analysis

Background: Acute kidney injury (AKI) is a common complication following solid-organ transplantation. However, the epidemiology of AKI and mortality risk of AKI among patients undergoing cardiac transplantation is not uniformly described. We conducted this study to assess the incidence of AKI and mortality risk of AKI in adult patients after cardiac transplantation. Methods: A systematic review of EMBASE, MEDLINE, and Cochrane Databases was performed until June 2019 to identify studies evaluating the incidence of AKI (by standard AKI definitions), AKI requiring renal replacement therapy (RRT), and mortality risk of AKI in patients undergoing cardiac transplantation. Pooled AKI incidence and mortality risk from the included studies were consolidated by random-effects model. The protocol for this study is registered with PROSPERO (no. CRD42019134577). Results: 27 cohort studies with 137,201 patients undergoing cardiac transplantation were identified. Pooled estimated incidence of AKI and AKI requiring RRT was 47.1% (95% CI: 37.6-56.7%) and 11.8% (95% CI: 7.2-18.8%), respectively. The pooled ORs of hospital mortality and/or 90-day mortality among patients undergoing cardiac transplantation with AKI and AKI requiring RRT were 3.46 (95% CI, 2.40-4.97) and 13.05 (95% CI, 6.89-24.70), respectively. The pooled ORs of 1-year mortality among patients with AKI and AKI requiring RRT were 2.26 (95% CI, 1.56-3.26) and 3.89 (95% CI, 2.49-6.08), respectively. Conclusion: Among patients undergoing cardiac transplantation, the incidence of AKI and severe AKI requiring RRT are 47.1% and 11.8%, respectively. AKI post cardiac transplantation is associated with reduced short term and 1-year patient survival.

Predictors of 1-year mortality in heart transplant recipients: a systematic review and meta-analysis

Objective

A systematic summary of the observational studies informing heart transplant guideline recommendations for selection of candidates and donors has thus far been unavailable. We performed a meta-analysis to better understand the impact of such known risk factors.

Methods

We systematically searched and meta-analysed the association between known pretransplant factor and 1-year mortality identified by multivariable regression models. Our review used the Grading of Recommendations, Assessment, Development and Evaluation for assessing the quality of assessment. We pooled risk estimates by using random effects models.

Results

Recipient variables including age (HR 1.16 per 10-year increase, 95% CI 1.10–1.22, high quality), congenital aetiology (HR 2.35, 95% CI 1.62 to 3.41, moderate quality), diabetes (HR 1.37, 95% CI 1.15 to 1.62, high quality), creatinine (HR 1.11 per 1 mg/dL increase, 95% CI 1.06 to 1.16, high quality), mechanical ventilation (HR 2.46, 95% CI 1.48 to 4.09, low quality) and short-term mechanical circulatory support (MCS) (HR 2.47, 95% CI 1.04 to 5.87, low quality) were significantly associated with 1-year mortality. Donor age (HR 1.20 per 10-year increase, 95% CI 1.14 to 1.26, high quality) and female donor to male recipient sex mismatch (HR 1.38, 95% CI 1.06 to 1.80, high quality) were significantly associated with 1-year mortality. None of the operative factors proved significant predictors.

Conclusion

High-quality and moderate-quality evidence demonstrates that recipient age, congenital aetiology, creatinine, pulsatile MCS, donor age and female donor to male recipient sex mismatch are associated with 1-year mortality post heart transplant. The results of this study should inform future guideline and predictive model development.

Heart Transplantation in Asia

Heart transplantation (HTx) is the effective way to improve quality of life as well as survival in terminal heart failure (HF) patients. Since the first heart transplant in 1968 in Japan and in earnest in 1987 at Taiwan, HTx has been continuously increasing in Asia. Although the current percentage of heart transplants from Asia comprises only 5.7% of cases in the International Society of Heart and Lung Transplantation (ISHLT) registry, the values were under-reported and soon will be greatly increased. HTx in Asia shows comparable with or even better results compared with ISHLT registry data. Several endemic infections, including type B hepatitis, tuberculosis, and cytomegalovirus, are unique aspects of HTx in Asia, and need special attention in transplant care. Although cardiac allograft vasculopathy (CAV) is considered as a leading cause of death after HTx globally, multiple observations suggest less prevalence and benign nature of CAV among Asian populations. Although there are many obstacles such as religion, social taboo or legal process, Asian countries will keep overcoming obstacles and broaden the field of HTx.