Cardiac surgery late after heart transplantation: A safe and effective treatment option

Structural heart transcatheter interventions in orthotopic cardiac transplant and left ventricular assist devices recipients: A nationwide study

BACKGROUND

The current incidence and outcomes of structural transcatheter procedures in heart transplant (HTx) recipients and left-ventricular assist devices (LVAD) carriers is unknown.

AIMS

To provide insights on structural transcatheter procedures performed across HTx and LVAD patients in Spain.

METHODS

Multicenter, ambispective, observational nationwide registry.

RESULTS

Until May/2023, 36 percutaneous structural interventions were performed (78% for HTx and 22% for LVAD) widely varying among centers (0%-1.4% and 0%-25%, respectively). Percutaneous mitral transcatheter edge-to-edge (TEER) was the most common (n = 12, 33.3%), followed by trancatheter aortic valve replacement (n = 11, 30.5%), and tricuspid procedures (n = 9, 25%). Mitral TEER resulted in mild residual mitral regurgitation in all but one case, mean gradient was <5 mmHg in 75% of them at 1-year, with no mortality and 8.3% re-admission rate. Tricuspid TEER resulted in 100% none/mild residual regurgitation with a 1-year mortality and readmission rates of 22% and 28.5%, respectively. Finally, trancatheter aortic valve replacement procedures (n = 8 in LVADs due to aortic regurgitation and n = 3 in HTx), were successful in all cases with one prosthesis degeneration leading to severe aortic regurgitation at 1-year, 18.2% mortality rate and no re-admissions. Globally, major bleeding rates were 7.9% and 12.5%, thromboembolic events 3.7% and 12.5%, readmissions 37% and 25%, and mortality 22% and 25%, in HTx and LVADs respectively. No death was related to the implanted transcatheter device.

CONCLUSIONS

Most centers with HTx/LVAD programs perform structural percutaneous procedures but with very inconsistent incidence. They were associated with good safety and efficacy, but larger studies are required to provide formal recommendations.

Partial heart transplantation: Growing heart valve implants for children

Heart valves serve a vital hemodynamic function to ensure unidirectional blood flow. Additionally, native heart valves serve biological functions such as growth and self-repair. Heart valve implants mimic the hemodynamic function of native heart valves, but are unable to fulfill their biological functions. We developed partial heart transplantation to deliver heart valve implants that fulfill all functions of native heart valves. This is particularly advantageous for children, who require growing heart valve implants. This invited review outlines the past, present and future of partial heart transplantation.

Partial Heart Transplant in a Neonate With Irreparable Truncal Valve Dysfunction

Importance

The treatment of neonates with irreparable heart valve dysfunction remains an unsolved problem because there are no heart valve implants that grow. Therefore, neonates with heart valve implants are committed to recurrent implant exchanges until an adult-sized valve can fit.

Objective

To deliver the first heart valve implant that grows.

Design, Setting, and Participants

Case report from a pediatric referral center, with follow-up for more than 1 year. Participants were a recipient neonate with persistent truncus arteriosus and irreparable truncal valve dysfunction and a donor neonate with hypoxic-ischemic brain injury.

Intervention

First-in-human transplant of the part of the heart containing the aortic and pulmonary valves.

Main Outcomes and Measures

Transplanted valve growth and hemodynamic function.

Results

Echocardiography demonstrated adaptive growth and excellent hemodynamic function of the partial heart transplant valves.

Conclusions and Relevance

In this child, partial heart transplant delivered growing heart valve implants with a good outcome at age 1 year. Partial heart transplants may improve the treatment of neonates with irreparable heart valve dysfunction.

Outcomes of left-sided heart valve surgery after heart transplantation: a systematic review

As the survival after heart transplantation (HTx) is steadily improving, an increasing number of patients with late cardiac pathologies such as valvular disease is expected to rise. Nevertheless, no guidelines for indication of redo cardiac surgery after HTx exists. The aim of the present systematic review is to describe the results reported in the literature of surgical management of severe aortic and/or mitral valve disease. A systematic review was conducted including studies reporting on adult patients with severe mitral or aortic valve pathology needing surgery after their previous HTx. Exclusion criteria consisted in surgery with no left heart valve surgery, concomitant valve surgery during heart transplant, transcatheter interventions, and heterotopic HTx. A total of 35 papers met our inclusion criteria out of 2755 potentially eligible studies with 44 mitral valve surgery patients and 20 aortic valve surgery patients. In the entire population, the mean time from HTx to reintervention was 6.19 ± 5.22 years. After a mean follow-up of 2.78 ± 3.54 years and 1.53 ± 2.26 years from reintervention, 65.6% mitral and 86.7% aortic patients were reported as alive, respectively. As guidelines on cardiac surgery after HTx are currently lacking, left-sided valvular cardiac reinterventions can be considered a possible therapeutic approach in carefully selected patients. These interventions may not only improve the patient's functional status and survival, but may ultimately reduce the need for re-transplantation due to the chronic shortage of donor hearts. However, the support of more robust data is warranted.

Outcomes of tricuspid valve prostheses after heart transplantation: a systematic review

Tricuspid regurgitation (TR) is the most common valvular pathology after heart transplantation (HTx) and endomyocardial biopsy (EMB) remains responsible for the majority of cases due to the high probability of structural valve damage. The aim of the present review was to describe the results of surgical management of severe tricuspid regurgitation through tricuspid valve replacement (TVR) after a previous HTx. A systematic review was conducted by searching Pubmed, ScienceDirect, SciELO, DOAJ, and Cochrane databases until June 2023 for publications reporting patients undergoing TVR surgery after a previous HTx. If no right heart valve surgery was undertaken, or a heterotopic heart transplant was performed, or if the concomitant procedure was performed during the transplant itself, the paper was excluded. Twenty articles met our inclusion criteria out of 1532 potentially eligible studies, with a total of 300 patients. Mean age was 55.1 ± 9.6 years, and 85.1% were male. The mean number of EMB per patient was 31.1 ± 5.5 with a mean time between HTx and TVR of 7.64 ± 3.31 years. Bioprostheses were used in 83.3% of cases and 75.0% of patients with a bioprosthesis were reported as alive at last follow-up. Tricuspid valve repair is a valuable option, but these patients will be susceptible to recurrent TR after EMB. TVR with a bioprosthesis may provide the optimal solution for this subset of patients, as EMB is not feasible with a mechanical valve.

Partial heart xenotransplantation: A research protocol in non-human primates

Partial heart transplantation is a new type of transplant that delivers growing heart valve replacements for babies. Partial heart transplantation differs from orthotopic heart transplantation because only the part of the heart containing the heart valve is transplanted. It also differs from homograft valve replacement because viability of the graft is preserved by tissue matching, minimizing donor ischemia times, and recipient immunosuppression. This preserves partial heart transplant viability and allows the grafts to fulfill biological functions such as growth and self-repair. These advantages over conventional heart valve prostheses are balanced by similar disadvantages as other organ transplants, most importantly limitations in donor graft availability. Prodigious progress in xenotransplantation promises to solve this problem by providing an unlimited source of donor grafts. In order to study partial heart xenotransplantation, a suitable large animal model is important. Here we describe our research protocol for partial heart xenotransplantation in nonhuman primates.

Transcatheter tricuspid valve edge-to-edge repair after a heart transplant: a single-centre experience with a novel therapy†

OBJECTIVES

Tricuspid regurgitation (TR) in patients who had heart transplants is associated with poor outcome. The increased risk for surgical and postoperative complications might be reduced in these vulnerable patients by transcatheter therapies.

METHODS

All patients with a prior heart transplant (HTX) undergoing transcatheter edge-to-edge repair in the tricuspid position (T-TEER) were prospectively enrolled in an institutional registry.

RESULTS

Seven patients who had heart transplants (5/7 female) at a mean age of 53 [48; 64] and median TRI-SCORE of 14 [7; 22] underwent T-TEER to treat symptomatic TR ≥ IV in an elective (n = 6) and urgent (n = 1) setting, respectively. The median time from HTX to T-TEER was 13 years. A total of 2 (n = 4) and 3 (n = 3) clips were implanted with a technical success in 6/7 (one single- device detachment). TR reduction was effective and durable within a median echocardiographic follow-up time of 10 months (TR baseline vs last follow-up: P = 0.03). Further, significant right ventricular remodelling (right ventricular end-diastolic diameter: 50 mm-36 mm, P = 0.02), decrease in the inferior vena cava diameter (24 mm-18 mm, P = 0.04) and in the gamma-glutamyl-transferase (255 U/l-159 U/l, P = 0.04) was found. Four of 7 patients were free of cardiovascular death (n = 1, 267 days after T-TEER), cardiac redo surgery (n = 1) and heart failure hospitalization (n = 2) and had no further clinical signs of right heart failure.

CONCLUSIONS

T-TEER after HTX is feasible and effective regarding TR reduction in a short-term follow-up. The initial results may pave the way for a novel approach in TR management in patients having HTX.

Partial Heart Transplantation in Adult Cardiac Surgery

Many young adults require heart valve replacements. Current options for valve replacement in adults include mechanical valves, bioprosthetic valves, or the Ross procedure. Of these, mechanical and bioprosthetic valves are the most common options, although mechanical valve usage predominates in younger adults due to durability, while bioprosthetic valve usage predominates in older adults. Partial heart transplantation is a new method of valvular replacement that can deliver durable and self-repairing valves and allow adult patients freedom from anticoagulation therapy. This procedure involves transplantation of donor heart valves only, permitting expanded utilization of donor hearts as compared with orthotopic heart transplantation. In this review, we discuss the potential benefits of this procedure in adults who elect against the anticoagulation regimen required of mechanical valve replacements, although it has not yet been clinically established. Partial heart transplantation is a promising new therapy for the treatment of pediatric valvular dysfunction. This is a novel technique in the adult population with potential utility for valve replacement in young patients for whom anticoagulation therapy is problematic, such as women who wish to become pregnant, patients with bleeding disorders, and patients with active lifestyles.

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.

Indications, Complications, and Outcomes of Cardiac Surgery After Heart Transplantation: Results From the Cash Study

Background

Allograft pathologies, such as valvular, coronary artery, or aortic disease, may occur early and late after cardiac transplantation. Cardiac surgery after heart transplantation (CASH) may be an option to improve quality of life and allograft function and prolong survival. Experience with CASH, however, has been limited to single-center reports.

Methods

We performed a retrospective, multicenter study of heart transplant recipients with CASH between January 1984 and December 2020. In this study, 60 high-volume cardiac transplant centers were invited to participate.

Results

Data were available from 19 centers in North America (n = 7), South America (n = 1), and Europe (n = 11), with a total of 110 patients. A median of 3 (IQR 2–8.5) operations was reported by each center; five centers included ≥ 10 patients. Indications for CASH were valvular disease (n = 62), coronary artery disease (CAD) (n = 16), constrictive pericarditis (n = 17), aortic pathology (n = 13), and myxoma (n = 2). The median age at CASH was 57.7 (47.8–63.1) years, with a median time from transplant to CASH of 4.4 (1–9.6) years. Reoperation within the first year after transplantation was performed in 24.5%. In-hospital mortality was 9.1% (n = 10). 1-year survival was 86.2% and median follow-up was 8.2 (3.8–14.6) years. The most frequent perioperative complications were acute kidney injury and bleeding revision in 18 and 9.1%, respectively.

Conclusion

Cardiac surgery after heart transplantation has low in-hospital mortality and postoperative complications in carefully selected patients. The incidence and type of CASH vary between international centers. Risk factors for the worse outcome are higher European System for Cardiac Operative Risk Evaluation (EuroSCORE II) and postoperative renal failure.

Surgical techniques for aortic valve xenotransplantation

Background

Heart valve replacement in neonates and infants is one of the remaining unsolved problems in cardiac surgery because conventional valve prostheses do not grow with the children. Similarly, heart valve replacement in children and young adults with contraindications to anticoagulation remains an unsolved problem because mechanical valves are thrombogenic and bioprosthetic valves are prone to early degeneration. Therefore, there is an urgent clinical need for growing heart valve replacements that are durable without the need for anticoagulation.

Methods

A human cadaver model was used to develop surgical techniques for aortic valve xenotransplantation.

Results

Aortic valve xenotransplantation is technically feasible. Subcoronary implantation of the valve avoids the need for a root replacement.

Conclusion

Aortic valve xenotransplantation is promising because the development of GTKO.hCD46.hTBM transgenic pigs has brought xenotransplantation within clinical reach.

Transcatheter aortic valve replacement 24 years after cardiac transplantation

As patient survival after cardiac transplantation has improved over the course of the last several decades, clinicians are now faced with late complications. This includes aortic stenosis which, traditionally, has been treated with reoperative sternotomy and aortic valve replacement. Transcather aortic valve replacement (TAVR) offers a minimally invasive alternative in this high-risk population. A small but growing number of cases of TAVR after heart transplantation in high-risk patients have been reported in the last 10 years; we now present a case of aortic valve replacement via a transcatheter approach 24 years after cardiac transplantation.

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

BACKGROUND

Survival rates following cardiac transplantation continue to improve. Due to the scarcity of available organs, extended donor criteria have become more prevalent in clinical practice. In this context, the risk of developing cardiac pathology requiring surgical correction is increasing.

METHODS

Between January 1991 and October 2010, a total of 479 patients received cardiac transplantations at the University Hospital Heidelberg. Of those, 18 (3.8%) patients required subsequent cardiac surgery until 2018. Short- and long-term analyses were performed.

RESULTS

Indications for cardiac surgery included valvular disease (n = 16) with the majority of cases affecting the tricuspid valve (n = 10), while 6 patients received mitral valve surgery, of whom 3 patients underwent concomitant valve surgery. Other indications included CABG (n = 1) and re-transplantation (n = 1) for allograft dysfunction. Mean follow-up time was 6.5 years, while mean interval to surgery was 6.0 years. Early mortality was 11.1% (n = 2), while overall survival at 1, 5, and 10 years were, 88.1%, 81.4%, and 52.2%, respectively. Compared to an overall survival of that transplant cohort at 1, 5, and 10 years of 76.7%, 66.7%, and 52.4% percent, respectively (P = .271).

CONCLUSION

According to our data, redo cardiac surgery can be performed with acceptable mortality and morbidity. Atrioventricular valve pathology plays a chief role in these patients.

A Clean Cut: Minimally Invasive Mitral Valve Replacement after Heart Transplantation

A 50-year-old female presented with progressive heart failure due to obstruction of the mitral valve after heart transplantation in 2008. Through the occlusion catheter (IntraClude Intra-Aortic Occlusion Device), aortic cross-clamping, antegrade cardioplegia, and aortic root venting were performed.

Our case reports the first published study on minimally invasive mitral valve replacement for valve stenosis through intraluminal aortic clamping. The hazard of traumatic injuries can be reduced by avoiding resternotomy and circumventing adhesions between the aorta and the pulmonary artery after heart transplantation. Minimally invasive valve surgery is a safe and effective method with regard to short- and long-term results, especially in redo operations.

Transcatheter aortic valve implantation in an orthotopic heart transplant recipient with bicuspid aortic valve

Increasing longevity of heart transplantation recipients and aging donor population accompanied by the older age at transplantation led to an increase in the prevalence of degenerative valvular disease in particular aortic stenosis. TAVI is considered a safe and feasible alternative compared to conventional SAVR in this high-risk population.

Cardiac Surgery After Heart Transplantation: Elective Operation or Last Exit Strategy?

Background

Because of improved long-term survival after heart transplantation (HTx), late graft pathologies such as valvular disease or cardiac allograft vasculopathy (CAV) might need surgical intervention to enhance longer survival and ensure quality of life. To this date, there exist no guidelines for indication of cardiac surgery other than retransplantation after HTx.

Methods

In this retrospective, single-center study, we evaluated patients who underwent cardiac surgery after HTx at our institution.

Results

Between March 1984 and October 2016, 17 (1.16%) of 1466 HTx patients underwent cardiac surgery other than retransplantation after HTx. Indication were valvular disease (n = 7), CAV (n = 6), and other (n = 4). Of these, 29.4% (n = 5) were emergency procedures and 70.6% were elective cases. Median age at time of surgery was 61 years (interquartile range, 52-66 years); 82.4% (n = 14) were male. Median time to surgery after HTx was 9.3 years (2.7-11.1 years). In-hospital, mortality was 11.8% (n = 2); later need of retransplantation was 11.8% (n = 2) due to progressing CAV 3 to 9 months after surgery. One-year survival was 82.35%; overall survival was 47.1% (n = 8) with a median follow-up of 1477 days (416-2135 days). Overall survival after emergency procedures was 209 days (36-1119.5 days) whereas, for elective procedures, it was 1583.5 days (901.5-4319 days).

Conclusions

Incidence of cardiac surgery after HTx in our cohort was low (1.16%) compared with that of other studies. In elective cases, long-term survival was good.

Current Expectations for Cardiac Transplantation in Patients With Congenital Heart Disease

Congenital heart disease accounts for 40% of pediatric heart transplants and presents unique challenges to the transplant team. Suitability for transplantation is defined in part by degree of sensitization, pulmonary vascular resistance, and hepatic reserves. The incremental transplant risk for patients with congenital heart disease occurs within the first 3 months, after which survival is equivalent to transplantation for cardiomyopathy. Single ventricle with prior palliation, and especially the failing Fontan, carry the highest risk for transplantation and are least amenable to bridging with mechanical circulatory support. More effective bridging to transplant with mechanical circulatory support will require improvements in the adverse event profile of available pumps and the introduction of miniaturized continuous flow technology. The major barriers to routine long-term survival are chronic allograft failure and allograft vasculopathy. Despite these many challenges, continuing improvements in the care of pediatric heart transplant patients have pushed the median posttransplant survival past 15 years for children and to 20 years for infants.

Transcatheter aortic valve implantation for degenerative aortic valve regurgitation long after heart transplantation

Transcatheter aortic valve implantation (TAVI) has become a feasible therapeutic option for the management of high-risk patients with severe degenerative aortic stenosis. Recently it has been extended to high-risk patients with severe aortic regurgitation. Degenerative aortic valve disease is generally uncommon in heart transplant recipients. We report the case of a 75-year-old man in whom severe degenerative aortic regurgitation developed 14 years after heart transplantation (HTx). Because of multiple comorbidities and high surgical risk, TAVI was preferred. A 29-mm CoreValve prosthesis (Medtronic Inc, Minneapolis, MN) was successfully implanted using a transfemoral approach.

Off-pump coronary artery bypass grafting for a left main lesion due to cardiac allograft vasculopathy in Japan: first report of a case

Cardiac allograft vasculopathy (CAV) is a major cause of mortality after transplantation. We treated a 44-year-old female with off-pump coronary artery bypass grafting (OPCAB) 4 years after heart transplantation. Annual examinations, including coronary angiography and intravenous ultrasound (IVUS), revealed a severe lesion in the left main trunk. The left internal mammary artery was successfully anastomosed to the left anterior descending artery in an off-pump manner. To ensure that patients have a good long-term outcome after heart transplantation, routine examinations, including IVUS, are crucial, because of the nature of CAV. OPCAB is a good option for a left main trunk lesion due to CAV.