Cardiac surgery in the heart transplant recipient: Outcome analysis and long-term results

Influence of Tricuspid Regurgitation After Heart Transplantation: A Single-center Experience

Tricuspid valve regurgitation (TVR) is often observed after orthotopic heart transplantation. However, there is a scarcity of data regarding long-term outcomes of patients with TVR.

Methods

Between January 2008 and December 2015, 169 patients underwent orthotopic heart transplantation at our center and were included in this study. TVR trends and associated clinical parameters were retrospectively analyzed. TVR was assessed after 30 d, 1 y, 3 y, and 5 y, and groups were defined according to changes in TVR grade: constant (group 1; n = 100), improvement (group 2; n = 26), and deterioration (group 3; n = 43). Survival, outcome with regard to operative technique, and long-term kidney and liver function during follow-up were assessed.

Results

Mean follow-up time was 7.67 ± 4.17 y (median 8.62, Q1 5.06, Q3 11.16). Overall mortality was 42.0%, with differences between the groups (P < 0.01). Cox regression analysis revealed improvement of TVR as a significant predictor for survival (hazard ratio 0.23; 95% confidence interval, 0.08-0.63, P < 0.01). After 1 y 2.7%, after 3 y 3.7%, and after 5 y 3.9% of the patients showed persistent severe TVR. Creatinine levels after 30 d and 1, 3, and 5 y showed significant differences between the groups (P = 0.02, P < 0.01, P < 0.01, and P = 0.01), deterioration of TVR being associated with higher creatinine levels during follow-up.

Conclusions

Deterioration of TVR is associated with higher mortality and renal dysfunction. Improvement of TVR may function as a positive predictor for long-term survival after heart transplantation. Improvement of TVR should be a therapeutic goal offering a prognostic value for long-term survival.

Neuregulin-1, in a Conducive Milieu with Wnt/BMP/Retinoic Acid, Prolongs the Epicardial-Mediated Cardiac Regeneration Capacity of Neonatal Heart Explants

Rationale: Cardiac sympathetic nerves are required for endogenous repair of the mammalian neonatal heart in vivo, but the underlying mechanism is unclear. Objective: We tested the hypothesis that a combination of cardiac developmental growth factors Wnt3a, BMP4 and Neuregulin (NRG-1), compensate for denervation and support cardiac regeneration in explanted neonatal mammalian hearts. Methods and Results: Hearts from 2-day old neonatal mice were harvested, lesioned at the apex and grown ex vivo for 21 days under defined conditions. Hearts grown in canonical cardiomyocyte culture media underwent complete coagulative necrosis, a process resembling ischemic cell death, by day 14. However, the addition of Wnt3a, BMP-4 and NRG-1, maintained cellular integrity and restored the endogenous regenerative program. None of these factors alone, or in any paired combination, were sufficient to induce regeneration in culture. rNRG-1 alone significantly reduced the accumulation of double strand DNA damage at Day 3; (-NRG-1: 60±12%; +NRG-1: 8±3%; P<0.01) and prevented coagulative necrosis at Day 14. Short-term addition of rWnt3a and rBMP-4 (day 0-3, NRG-1+) increased WT1 expression (a marker of epicardial cells) 7-fold, epicardial proliferation (78±17 cells vs. 21±9 cells; P<0.05), migration and recellularization (80±22 vs. zero cells; P<0.01; n=6) at the injury site on day 14. Conclusions: A novel explant culture system maintains three-dimensional neonatal mouse hearts and the mammalian neonatal cardiac regenerative program ex vivo. We identified that rNRG-1, plus short-term activation of Wnt- and BMP-signaling, promotes cardiac repair via epicardial cell activation, their proliferation and migration to the injury site, followed by putative cardiomyocyte recruitment. This novel technique will facilitate future studies of mammalian cardiac regeneration and may be useful in cardiac-specific drug testing.

A Meta-Analysis on Prophylactic Donor Heart Tricuspid Annuloplasty in Orthotopic Heart Transplantation: High Hopes from a Small Intervention

(1) Background: Tricuspid regurgitation (TR) is the most frequent valvulopathy in heart transplant recipients (HTX). We aimed to assess the influence of prophylactic donor heart tricuspid annuloplasty (TA) in orthotopic HTX (HTX-A), comparing the outcomes with those of HTX patients. (2) Methods: Electronic databases of PubMed, EMBASE, and SCOPUS were searched. The endpoints were as follows: the overall rate of postprocedural TR (immediate, one week, six months, and one year after the procedure), postoperative complications (permanent pacemaker implantation rate, bleeding), redo surgery for TR, and mortality. (3) Results: This meta-analysis included seven studies. Immediate postprocedural, one-week, six-month and one-year tricuspid insufficiency rates were significantly lower in the HTX-A group. There was no difference in permanent pacemaker implantation rate between the groups. The incidence of postoperative bleeding was similar in both arms. The rate of redo surgery for severe TR was reported only by two authors. In both publications, the total number of events was higher in the HTX cohort, meanwhile pooled effect analysis showed no difference among the intervention and control groups. Mortality at one year was similar in both arms. (4) Conclusion: Our study showed that donor heart TA reduces TR incidence in the first year after orthotopic heart transplantation without increasing the surgical complexity. This is a potentially important issue, given the demand for heart transplants and the need to optimize outcomes when this resource is scarce.