The decline in kidney function after heart transplantation and its impact on survival.

BACKGROUND: Evidence of decline in native renal function after heart transplantation (HTx) in the Asian population is limited. This study determined the incidence and risk factors associated with declining kidney function after HTx and its impact on survival. METHODS: A retrospective study of consecutive adult heart transplant patients was conducted in a single center between 2010 and 2020. The decline in kidney function was defined as the presence of one of the following criteria, including a ≥ 40% decline in eGFR, absolute value <15 mL/min/1.73 m2 (calculated by the CKD-EPI method), doubling of serum creatinine, or dialysis. RESULTS: A total of 79 patients (77% male, mean age 44.5 ± 11.53 years, with a mean eGFR at discharge from the heart transplant admission of 87.9 ± 25.48 mL/min/1.73 m2 ) were included. During the median follow-up of 42 months, the rate of decline in eGFR was 3.9 mL/min/1.73 m2 per year, with a cumulative probability of decline in kidney function of 22% at 1 year and 43% at 5 years. The need for dialysis was 2.5% at 1 year and 5% at 5 years. The decline in kidney function within 1 year after discharge (hazard ratio (HR), 22.24; p = .007) and pre-HTx diabetes mellitus (DM) (HR, 8.99; p = .034) were independently associated with the need for dialysis. Post-HTx dialysis predicted all-cause mortality (HR, 4.47; p = .017). CONCLUSIONS: Approximately 20% of HTx patients developed a decline in kidney function within 1 year after discharge. These individuals and pre-HTx DM patients needed preventive measures to prevent progression to chronic dialysis, which impacted survival. (thaiclinicaltrials.org number, TCTR20230620004).

Primary isolated right ventricular failure after heart transplantation: prevalence, right ventricular characteristics, and outcomes.

To determine the prevalence, right ventricular (RV) characteristics, and outcomes of primary isolated RV failure (PI-RVF) after heart transplant (HTX). PI-RVF was defined as (1) the need for mechanical circulatory support post-transplant, or (2) evidence of RVF post-transplant as measured by right atrial pressure (RAP) > 15 mmHg, cardiac index of < 2.0 L/min/m2 or inotrope support for < 72 h, pulmonary capillary wedge pressure < 18 mmHg, and transpulmonary gradient < 15 mmHg with pulmonary systolic pressure < 50 mmHg. PI-RVF can be diagnosed from the first 24-72 h after completion of heart transplantation. A total of 122 consecutive patients who underwent HTX were reviewed. Of these, 11 were excluded because of secondary causes of graft dysfunction (GD). PI-RVF was present in 65 of 111 patients (59%) and 31 (48%) met the criteria for PGD-RV. Severity of patients with PI-RVF included 41(37%) mild, 14 (13%) moderate, and 10 (9%) severe. The median onset of PI-RVF was 14 (0-49) h and RV recovery occurred 5 (3-14) days after HTX. Severe RV failure was a predictor of 30-day mortality (HR 13.2, 95% CI 1.6-124.5%, p < 0.001) and post-transplant dialysis (HR 6.9, 95% CI 2.0-257.4%, p = 0.001). Patients with moderate PI-RVF had a higher rate of 30-day mortality (14% vs. 0%, p = 0.014) and post-operative dialysis (21% vs. 2%, p = 0.016) than those with mild PI-RVF. Among patients with mild and moderate PI-RVF, patients who did not meet the criteria of PGD-RV had worsening BUN/creatinine than those who met the PGD-RV criteria (p < 0.05 for all). PI-RVF was common and can occur after 24 h post-HTX. The median RV recovery time was 5 (2-14) days after HTX. Severe PI-RVF was associated with increased rates of 30-day mortality and post-operative dialysis. Moderate PI-RVF was also associated with post-operative dialysis. A revised definition of PGD-RV may be needed since patients who had adverse outcomes did not meet the criteria of PGD-RV.

Circulating growth differentiation factor-15 as a novel biomarker in heart transplant.

AIMS: This study aimed to examine (i) whether circulating growth differentiation factor-15 (GDF-15) is associated with acute cellular cardiac allograft rejection (ACR); (ii) a longitudinal trend of GDF-15 after heart transplantation; and (iii) the prognostic value of GDF-15 in predicting a composite outcome of severe primary graft dysfunction (PGD) and 30 day mortality post-transplant. METHODS AND RESULTS: Serum samples were collected before heart transplantation and at every endomyocardial biopsy (EMB) post-heart transplantation in de novo transplant patients. A total of 60 post-transplant serum samples were matched to the corresponding EMBs. Seven (12%) were considered International Society for Heart Lung Transplantation Grade 1R ACR, and one (2%) was identified as Grade 2R ACR. GDF-15 levels in patients with ACR were not different from those in the non-rejection group (6230 vs. 6125 pg/mL, P = 0.27). GDF-15 concentration gradually decreased from 8757 pg/mL pre-transplant to 5203 pg/mL at 4 weeks post-transplant. The composite adverse outcome of PGD and 30 day mortality was significantly associated with increased post-operative GDF-15 (odds ratio: 40; 95% confidence interval: 2.01-794.27; P = 0.005) and high inotrope score post-transplant (odds ratio: 18; 95% confidence interval: 1.22-250.35; P = 0.01). CONCLUSIONS: Circulating GDF-15 concentration was markedly elevated in patients with end-stage heart failure and decreased after heart transplantation. GDF-15 was significantly associated with post-transplant PGD and mortality. A lack of association between ACR and GDF-15 did not support routine use of GDF-15 as a biomarker to detect ACR. However, GDF-15 may be potentially useful to determine heart transplant recipients at high risk for adverse post-transplant outcomes. We suggest that GDF-15 levels in recipient serum can provide risk stratification for severe PGD including death during post-operative period. This novel biomarker may serve to inform and guide timely interventions against severe PGD and adverse outcomes during the first 4 weeks after transplantation. Further studies to support the utility of GDF-15 in heart transplantation are required.

Endomyocardial Biopsy and Prevalence of Acute Cellular Rejection in Heart Transplantation.

BACKGROUND: Percutaneous endomyocardial biopsy (EMB) remains the criterion standard method for surveillance of allograft rejection after heart transplant (HT). However, data regarding utility of EMBs and prevalence of acute cellular rejection (ACR) in Asian populations are still limited. We aimed to report our experience in the use of EMBs and prevalence of ACR in HT recipients. METHODS: We retrospectively evaluated all EMBs from consecutive HT recipients between January 2008 and December 2018. EMB pathology results were according to International Society for Heart and Lung Transplantation 2004 revision of biopsy grading. We also divided patients into previous era and current era group (underwent HT before and after 2015) to compare prevalence of ACR and survival outcome. RESULTS: A total of 832 EMBs from 81 HT recipients were included. Pathologic reports revealed ACR grade 1R 22.8%, 2R 4.2%, and 3R 0.6%. At patient level, at least 1 episode of ACR grade 1R, 2R, and 3R were found in 70.6%, 24.7%, and 3.5% of the patients, respectively. When compared between era, frequency of EMB during the first year after HT in current era was significantly higher (9.74 ± 3.38 vs 4.93 ± 3.29, P < .001), but lower frequency of rejection grade ≥ 2R were found (2.3% vs 8.1%, P < .001). However, 1-year survival was not statistically different (76% in previous era vs 80% in current era, P = .37). CONCLUSIONS: From our study, prevalence of grade ≥ 2R rejection was approximately 5%, which is comparable with previous studies. Further studies are needed to evaluate proper interval and number of EMBs in HT recipients.

Low-dose basiliximab induction therapy in heart transplantation.

We prospectively studied efficacy and safety outcomes of two 10-mg doses of intravenous basiliximab on day 0 and day 4 for induction therapy in 17 consecutive de novo heart transplant recipients. By the 2-week assessment post-transplant, there were no deaths, graft failures, or acute cellular rejections (ACRs) ISHLT grade ≥ 2R. By the 1-year assessment post-transplant, there were 1 (6%) infectious death, no graft failures, 2 (12%) grade 2R ACRs, 6 (35%) asymptomatic cytomegalovirus (CMV) infections, and 4 (25%) treated infections. Our study was the first to show that low-dose basiliximab induction in heart transplant resulted in favorable efficacy and safety outcomes. Additionally, calcineurin inhibitor (CNI) initiation in a low-risk population could be safely delayed using the strategy of modified low-dose postoperative basiliximab. This strategy also appears to allow subsequent early corticosteroid wean, although with the concomitant maintenance of higher CNI levels and higher dosing of mycophenolate.