Utility of the IMPACT score for predicting heart transplant mortality. Analysis on a contemporary cohort of the Spanish Heart Transplant Registry.

INTRODUCTION AND OBJECTIVES: The Index for Mortality Prediction After Cardiac Transplantation (IMPACT) score was derived and validated as a predictor of mortality after heart transplantation (HT). The primary objective of this work is to externally validate the IMPACT score in a contemporary Spanish cohort. METHODS: Spanish Heart Transplant Registry data were used to identify adult (>16 years) HT patients between January 2000 and December 2015. Retransplantation, multiorgan transplantation and patients in whom at least one of the variables required to calculate the IMPACT score was missing were excluded from the analysis (N = 2810). RESULTS: Median value of the IMPACT score was five points (IQR: 3, 8). Overall, 1-year survival rate was 79.1%. Kaplan-Meier 1-year survival rates by IMPACT score categories (0-2, 3-5, 6-9, 10-14, ≥15) were 84.4%, 81.5%, 79.3%, 77.3%, and 58.5%, respectively (Log-Rank test: p < .001). Performance analysis showed a good calibration (Hosmer-Lemeshow chi-square for 1 year was 7.56; p = .47) and poor discrimination ability (AUC-ROC .59) of the IMPACT score as a predictive model. CONCLUSIONS: In a contemporary Spanish cohort, the IMPACT score failed to accurately predict the risk of death after HT.

Predictors of renal replacement therapy after heart transplantation and its impact on long-term survival.

BACKGROUND: Renal replacement therapy (RRT) after heart transplant (HT) is associated with worse prognosis. We aimed to identify predictors of RRT and the impact of this complication on long-term survival. METHODS: Cohort study of HT patients. Univariate and multivariate competing-risk regression was performed to identify independent predictors of RRT. The cumulative incidence function was plotted for RRT. The Kaplan-Meier method was used to compare long-term survival. RESULTS: We included 103 patients. At multivariate analysis, only the emergency status of HT (short-term mechanical circulatory support as a bridge to transplant), chronic kidney disease, and low oxygen delivery were independent predictors of RRT (subhazard ratio [SHR] 4.11, 95% CI 1.84-9.14; SHR 3.17, 95% CI 1.29-7.77; SHR 2.86, 95% CI 1.14-7.19, respectively). Elective HT patients that required RRT showed a significantly reduced survival comparable to patients with emergency HT and RRT (75% ± 13% vs. 67% ± 16%). The absence of RRT implied an excellent survival in patients with an emergency status of HT and elective HT (100% vs. 93% ± 4%). CONCLUSION: The emergency status of HT, chronic kidney disease, and low oxygen delivery were independent predictors of RRT. The occurrence of RRT increases the risk of death in elective HT as much as in patients with an emergency status.

Risk stratification of patients listed for heart transplantation while supported with extracorporeal membrane oxygenation.

OBJECTIVES: Extracorporeal membrane oxygenation (ECMO) is used to support patients in severe cardiogenic shock. In the absence of recovery, these patients may need to be listed for heart transplant (HT), which offers the best long-term prognosis. However, posttransplantation mortality is significantly elevated in patients who receive ECMO. The objective of the present study was to describe and risk-stratify different profiles of patients listed for HT supported by ECMO. METHODS: Patients listed for HT in the United Network for Organ Sharing database were analyzed. The primary outcome was 1-year survival and was assessed in patients bridged to transplant with ECMO (ECMOBTT) and patients who were previously supported on ECMO but had it removed before HT (ECMOREMOVED). RESULTS: Among 65,636 adult candidates listed for HT (between 2001 and 2017), 712 were supported on ECMO, 292 of whom (41%) underwent HT (ECMOBTT, n = 202; ECMOREMOVED, n = 90). Most of the patients with ECMOREMOVED were transplanted with a ventricular assist device. In ECMOBTT, recipient age (each 10-year increase), time on the waitlist (both defined as minor risk factors), need for dialysis, and need for mechanical ventilation (both defined as major risk factors) were independent predictors of mortality. ECMOREMOVED and ECMOBTT with no risk factors showed 1-year survival comparable to that in patients who were never supported on ECMO. Compared with patients who were never on ECMO, patients in ECMOBTT group with minor risk factors, 1 major risk factor, and 2 major risk factors had ~2-, ~5-, and >10-fold greater 1-year mortality, respectively (P < .05). CONCLUSIONS: The HT recipients in the ECMOREMOVED and ECMOBTT groups with no risk factors showed similar survival as the HT recipients who were never supported on ECMO. In the ECMOBTT group, posttransplantation mortality increased significantly with increasing risk factors.

Mechanical circulatory support in severe primary graft dysfunction: Peripheral cannulation but not earlier implantation improves survival in heart transplantation.

BACKGROUND: Primary graft dysfunction (PGD) still affects 2% to 28% of heart transplants (HT). Severe PGD requires mechanical circulatory support (MCS) and is the main cause of death early after HT. Earlier initiation has been suggested to improve prognosis but the best cannulation strategy is unknown. METHODS: Analysis of all HT in Spain between 2010 and 2020. Early (<3 hours after HT) vs late initiation (≥3 hours after HT) of MCS was compared. Special focus was placed on peripheral vs central cannulation strategy. RESULTS: A total of 2376 HT were analyzed. 242 (10.2%) suffered severe PGD, 171 (70.7%) received early MCS and 71 (29.3%) late MCS. Baseline characteristics were similar. Patients with late MCS had higher inotropic scores and worse renal function at the moment of cannulation. Early MCS had longer cardiopulmonary bypass times and late MCS was associated with more peripheral vascular damage. No significant differences in survival were observed between early and late implant at 3 months (43.82% vs 48.26%; log-rank p = 0.59) or at 1 year (39.29% vs 45.24%, log-rank p = 0.49). Multivariate analysis did not show significant differences favoring early implant. Survival was higher in peripheral compared to central cannulation at 3 months (52.74% vs 32.42%, log-rank p = 0.001) and 1 year (48.56% vs 28.19%, log-rank p = 0.0007). In the multivariate analysis, peripheral cannulation remained a protective factor. CONCLUSIONS: Earlier MCS initiation for PGD was not superior, compared to a more conservative approach with deferred initiation. Peripheral compared to central cannulation showed superior 3-month and 1-year survival rates.

The pharmaceutical management of cardiac allograft vasculopathy after heart transplantation.

INTRODUCTION: Cardiac allograft vasculopathy (CAV) is a major limitation to long-term survival after heart transplantation. Its peculiar pathophysiology involves multifactorial pathways including immune-mediated and metabolic risk factors, which are associated with the development of specific pathological lesions. The often diffuse and chronic nature of the disease reduces the effectiveness of revascularization procedures, and pharmacological prevention of the disease is the sole therapeutic approach with some proven efficacy. AREAS COVERED: In this article, after briefly outlining the risk factors for CAV, the authors revise the potential pharmacological approaches that may reduce the burden of CAV. While several therapies have shown convincing efficacy in terms of CAV prevention diagnosed by coronary imaging, very few have been reported to improve prognosis with any meaningful level of evidence. EXPERT OPINION: The authors believe that a customizable approach is necessary for clinical practice given the currently available evidence. Furthermore, it is important, in the future, to address the glaring therapeutic gap of an effective treatment against donor-specific antibodies, whose effect on endothelial injury is currently one of the major mechanisms of CAV development and for which no pharmacological treatment is currently available.

Predictors of Improvement in Renal Function After Heart Transplant.

OBJECTIVES: Moderate chronic renal insufficiency is often found in patients evaluated for heart transplant. Recovery of cardiac output after heart transplant might lead to improvement of renal function. In this study, our aim was to identify predictors of improvement of renal function after heart transplant. MATERIALS AND METHODS: Our study included a cohort of heart transplant patients treated from 2011 to 2016 whose main outcome was improved renal function, defined as glomerular filtration rate at 6 months after heart transplant of ≥ 10% compared with baseline (before transplant). Univariate and multivariate logistic regression was used to identify independent predictors. RESULTS: Our study included 83 patients, with 29% having improvement in renal function. Multivariate analyses identified baseline glomerular filtration rate (odds ratio of 0.95; 95% confidence interval, 0.93-0.98; P = .005), absence of hypertension (odds ratio of 4.94; 95% confidence interval, 1.37-17.8; P = .015), and elective heart transplant (odds ratio of 13.71; 95% confidence interval, 1.33-141; P = .028) as independent predictors. A scale developed with independent predictors showed good accuracy (area under the curve of 0.76). The probability for improvement in renal function was 7%, 23%, and 58% in patients with low, medium, and high scores, respectively (P < .001). CONCLUSIONS: In patients with heart transplant, baseline glomerular filtration rate, absence of hypertension, and elective heart transplant were independent predictors of improvement in renal function after heart transplant.

Venoarterial extracorporeal membrane oxygenation with or without simultaneous intra-aortic balloon pump support as a direct bridge to heart transplantation: results from a nationwide Spanish registry.

OBJECTIVES: To investigate the potential clinical benefit of an intra-aortic balloon pump (IABP) in patients supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO) as a bridge to heart transplantation (HT). METHODS: We studied 169 patients who were listed for urgent HT under VA-ECMO support at 16 Spanish institutions from 2010 to 2015. The clinical outcomes of patients under simultaneous IABP support (n = 73) were compared to a control group of patients without IABP support (n = 96). RESULTS: There were no statistically significant differences between the IABP and control groups with regard to the cumulative rates of transplantation (71.2% vs 81.2%, P = 0.17), death during VA-ECMO support (20.6% vs 14.6%, P = 0.31), transition to a different mechanical circulatory support device (5.5% vs 5.2%, P = 0.94) or weaning from VA-ECMO support due to recovery (2.7% vs 0%, P = 0.10). There was a higher incidence of bleeding events in the IABP group (45.2% vs 25%, P = 0.006; adjusted odds ratio 2.18, 95% confidence interval 1.02-4.67). In-hospital postoperative mortality after HT was 34.6% in the IABP group and 32.5% in the control group (P = 0.80). One-year survival after listing for urgent HT was 53.3% in the IABP group and 52.2% in the control group (log rank P = 0.75). Multivariate adjustment for potential confounders did not change this result (adjusted hazard ratio 0.94, 95% confidence interval 0.56-1.58). CONCLUSIONS: In our study, simultaneous IABP therapy in transplant candidates under VA-ECMO support did not significantly reduce morbidity or mortality.

Preoperative Toxoplasma gondii serostatus does not affect long-term survival of cardiac transplant recipients. Analysis of the Spanish Heart Transplantation Registry.

BACKGROUND: It's unclear whether pre-transplant T. gondii seropositivity is associated with impaired survival in heart transplant recipients. OBJECTIVES: To test the above-mentioned hypothesis in the Spanish Heart Transplantation Registry. METHODS: Post-transplant outcomes of 4048 patients aged >16years who underwent first, single-organ heart transplantation in 17 Spanish institutions from 1984 to 2014 were studied. Long-term post-transplant survival and survival free of cardiac death or retransplantation of 2434 (60%) T. gondii seropositive recipients and 1614 (40%) T. gondii seronegative recipients were compared. RESULTS: T. gondii seropositive recipients were older, had higher body mass index, and presented higher prevalence of hypertension, hypercholesterolemia, COPD and Cytomegalovirus seropositivity than T. gondii seronegative recipients. In univariable analysis, pre-transplant T. gondii seropositivity was associated with increased post-transplant all-cause mortality (non-adjusted HR 1.15; 95% CI 1.04-1.26). However, this effect was no longer statistically significant after multivariable adjustment by recipient's age and sex (adjusted HR 1.01, 95% CI 0.92-1.11). Extended multivariable adjustment by other potential confounders showed similar results (adjusted HR 0.99, 95% CI 0.89-1.11). T. gondii seropositivity had no significant effect on the composite outcome cardiac death or retransplantation (non-adjusted HR 1.08, 95% CI 0.95-1.24, p=0.235). The distribution of the causes of death was comparable in T. gondii seropositive and T. gondii seronegative recipients. No statistically significant impact of donor's T. gondii serostatus or donor-recipient T. gondii serostatus matching on post-transplant survival was observed. CONCLUSIONS: Our analysis did not show a significant independent effect of preoperative T. gondii serostatus on long-term outcomes after heart transplantation.