Cardiac surgery in kidney and liver transplant recipients

Cardiovascular outcomes in solid organ transplant recipients undergoing cardiac surgery: A matched pair analysis

INTRODUCTION

This study aimed to compare postoperative outcomes after cardiac surgery in solid-organ transplant recipients and nontransplant patients.

METHODS

We performed a retrospective analysis of 78 consecutive transplant recipients who underwent cardiac surgery at Asan Medical Center between 2000 and 2022 and were matched with 312 nontransplant patients who underwent cardiac surgery at a 1:4 ratio. The outcomes included 30-day mortality, all-cause death, cardiac death, readmission, and cardiac readmission.

RESULTS

There was no significant difference in baseline characteristics between the two groups. The most common type of cardiac surgery performed in solid organ transplant recipients was isolated valve surgery, followed by isolated CABG. The 30-day mortality was not significantly different between transplant recipients and nontransplant patients (3.9% vs. 3.5%; P > .99). Solid organ transplant recipients showed a higher all-cause mortality compared to nontransplant patients (29.1% vs. 14.3% at 5 years; P = .001); however, there was no significant difference in cardiac death between the two groups (2.6% vs. 3.2% at 5 years; P = .80). In addition, the readmission and cardiac readmission rates showed comparable findings to that of mortality.

CONCLUSION

Cardiac surgery can be performed safely in solid organ transplant recipients, with postoperative cardiovascular outcomes comparable to those observed in nontransplant patients.

Impact of previous REnal TRansplantation on the mid-term renal Outcome after CARdiac surgery: the RETROCAR trial

BACKGROUND

Acute kidney injury (AKI) is one of the most common complications after cardiac surgery with cardiopulmonary bypass (CPB). Renal transplant recipients (RTRs) have a higher risk of cardiac surgery-associated AKI (CSA-AKI). A relationship has been strongly suggested between AKI and poor long-term graft survival. The main objective was to evaluate the impact of on-pump cardiac surgery on the 1-year renal allograft survival rate.

METHODS

The study population consisted of 37 RTRs and 56 non-RTRs who underwent cardiac surgery between 1 January 2010 and 31 December 2019. They were matched according to age, sex, preoperative glomerular function, diabetes and type of surgery. The primary composite outcome was renal survival, defined as patient survival without the requirement for permanent dialysis or new kidney transplantation at 1 year after surgery.

RESULTS

The renal survival rate was significantly lower in the RTR group than in the non-RTR group [81% versus 96%; odds ratio 0.16 (95% confidence interval 0.03-0.82), P = .03]. The proportion of patients who returned to permanent dialysis was higher in the RTR group than in the non-RTR group (12% versus 0%; P = .02). The proportion of patients with severe AKI was also higher in the RTR group. At 1 year after surgery, serum creatinine level, glomerular filtration rate and all-cause mortality rates were comparable between both groups.

CONCLUSION

Patients with a functional renal allograft have a low 1-year renal allograft survival rate after cardiac surgery with CPB. In addition, these patients have significant risks of AKI and acute kidney disease after open-heart surgery.

Inferior outcomes following cardiac surgery in patients with a functioning renal allograft

OBJECTIVES

Renal transplantation is an effective treatment for end-stage renal failure. The aim of this study was to evaluate outcomes for these patients undergoing cardiac surgery.

METHODS

A retrospective analysis identified patients with a functioning renal allograft at the time of surgery. A 2:1 propensity matching was performed. Patients were matched on: age, sex, left ventricle function, body mass index, preoperative creatinine, operation priority, operation category and logistic EuroSCORE.

RESULTS

Thirty-eight patients undergoing surgery with a functioning renal allograft were identified. The mean age was 62.4 years and 66% were male. A total of 44.7% underwent coronary artery bypass grafting and 26.3% underwent a single valve procedure. The mean logistic EuroSCORE was 10.65. The control population of 76 patients was well matched. Patients undergoing surgery following renal transplantation had a prolonged length of intensive care unit (3.19 vs 1.02 days, P < 0.001) and hospital stay (10.3 vs 7.17 days, P = 0.05). There was a higher in-hospital mortality (15.8% vs 1.3%, P = 0.0027). Longer-term survival on Kaplan-Meier analysis was also inferior (P < 0.001). One-year survival was 78.9% vs 96.1% and 5-year survival was 63.2% vs 90.8%. A further subpopulation of 11 patients with a failed renal allograft was identified and excluded from the main analysis; we report demographic and outcome data for them.

CONCLUSIONS

Patients with a functioning renal allograft are at higher risk of perioperative mortality and inferior long-term survival following cardiac surgery. Patients in this population should be appropriately informed at the time of consent and should be managed cautiously in the perioperative period with the aim of reducing morbidity and mortality.

Short-Term Outcomes of Transcatheter Aortic Valve Implantation Versus Surgical Aortic Valve Replacement in Kidney Transplant Recipients (from the US Nationwide Representative Study)

Kidney transplant recipients (KTRs) are considered high-risk patients for surgical interventions. Transcatheter aortic valve implantation (TAVI) has been introduced as an alternative to surgical aortic valve replacement (SAVR) in patients with aortic stenosis (AS) at high operative risk. However, the outcomes of TAVI compared with SAVR KTRs have not been well-studied in nationally representative data. Patients with prior history of functioning kidney transplant who were hospitalized for TAVI and SAVR between January 2012 and December 2017 were identified retrospectively in the Nationwide Readmissions Database. Our study included 762 TAVI and 1,278 SAVR KTRs. Compared with SAVR, TAVI patients generally had higher rates of co-morbidities with lower risk of in-hospital mortality (3.1% vs 6.3, p = 0.002), blood transfusion (11.5% vs 38.6%, p <0.001), acute myocardial infarction (3.9% vs 6.5%, p = 0.16), acute kidney injury (24.5% vs 42.1%, p <0.001), sepsis (3.9% vs 9.5%, p <0.001) and discharge with disability (42.6% vs 68.4%, p <0.001). However, the rate of permanent pacemaker implantation was significantly higher in TAVI group (11.4% vs 3.9%, p <0.001). Of note, in-hospital stroke and 30-day readmission were comparable between both groups. These findings were confirmed after adjusting for other co-morbidities. TAVI is growing as a valid and safe alternative for KTRs with severe AS.

Cardiac Surgery and Postoperative Renal Allograft Failure

BACKGROUND

Although cardiac surgery among renal allograft recipients is relatively safe, less is known about the impact of cardiac surgery on the functioning renal allograft. This study assessed postoperative renal failure among renal transplant recipients undergoing cardiac surgery.

METHODS

The study population was identified by matching medical record numbers from the United Network for Organ Sharing Kidney Transplant Database to a cardiovascular surgery database and The Society of Thoracic Surgeons Adult Cardiac Surgery Database for the authors' institution from January 1992 through August 2018.

RESULTS

One hundred seventy-nine renal transplant recipients with a functioning allograft underwent cardiac surgery a mean of 6.4 ± 5.6 years after renal transplantation. Thirty (17.6%) of the 170 patients either died or had allograft failure during the first postoperative year. Receiver-operating characteristics curve analysis using Cox regression demonstrated an optimal cutoff point for preoperative serum creatinine predicting postoperative allograft loss is 1.9 mg/dL (hazard ratio 3; 95% confidence interval, 1.5 to 6.9) with a model C statistic of 0.642.

CONCLUSIONS

The current study affirms findings in the literature that cardiac surgery in renal transplant recipients carries acceptable perioperative morbidity and mortality. Renal transplant recipients who underwent cardiac surgery had a constant hazard of renal allograft loss similar to that of the general transplant population. A preoperative serum creatinine value greater than 1.9 mg/dL increases the risk for long-term renal allograft loss after cardiac surgery.

Outcomes in patients with solid organ transplants undergoing cardiac surgery

OBJECTIVE

Long-term outcomes after cardiac surgery in solid organ transplant recipients are limited in the contemporary literature. The objective of this study is to evaluate postoperative outcomes in these patients, including variables associated with mortality and readmissions.

METHODS

All adults undergoing isolated coronary artery bypass grafting, isolated valve, or coronary artery bypass grafting + valve cardiac surgical procedures from 2011 to 2018 were included in this study. Patients with solid organ transplants undergoing cardiac surgery were studied. Primary outcomes included operative (30-day) and 5-year mortality.

RESULTS

A total of 11,190 patients underwent isolated coronary artery bypass grafting, isolated valve, or coronary artery bypass grafting + valve operations at our institution from 2011 to 2018. Of these, 129 patients (1%) had solid organ transplants and underwent isolated coronary artery bypass grafting (n = 84), isolated valve (n = 30), or coronary artery bypass grafting + valve (n = 15). Type of organ transplant included 84 patients (65%) with kidney, 27 patients (21%) with liver, 9 patients (7%) with heart, and 9 patients (7%) with lung transplants. The median Society of Thoracic Surgeons Predicted Risk Of Mortality for the cohort was 2.73 (Q1-Q3: 1.67-6.33). Three patients (2%) had an operative (30-day) mortality. Significant variables associated with 5-year mortality on multivariable Cox regression analysis included chronic obstructive pulmonary disease (hazard ratio, 2.44; 1.01-5.90; P = .048) and congestive heart failure (hazard ratio, 4.45; 1.81-10.9; P = .001). Significant variables associated with 5-year readmissions included chronic obstructive pulmonary disease, dialysis dependence, and concomittant valve surgery with coronary artery bypass grafting. Five-year readmission rate was 88%, and patients with valve operations (± coronary artery bypass grafting) had significantly lower (P = .009) freedom from readmission (6%).

CONCLUSIONS

Cardiac surgery can be performed with low operative mortality and good long-term survival in patients with solid organ transplants. Five-year hospital readmissions are common, with significantly more readmissions in patients who had valve procedures.

Outcomes of Patients Who Undergo Cardiac Surgical Procedures After Liver Transplantation

BACKGROUND

There is a paucity of information available regarding the impact of cardiac surgical procedures on patients who have undergone previous liver transplantation. The primary purpose of this study was to ascertain the survival rate and predictors of death in this specific patient population.

METHODS

This retrospective cohort study consisted of a consecutive series of patients with a functioning liver allograft who subsequently underwent cardiac surgical procedures between January 1991 and December 2012. The optimal Model for End-Stage Liver Disease (MELD) score for predicting late death was identified using receiver operating characteristic curve analysis. Risk of postoperative death was determined by parametric hazard analysis.

RESULTS

Between January 1991 and December 2012, 43 patients (median age, 60 years) underwent cardiac surgical procedures after liver transplantation. The median interval between liver transplant and cardiac operation was 63 months (range, 1.1 to 217 months). Three operative deaths and 24 late deaths occurred. Receiver operating characteristic curve analysis identified the optimal preoperative and postoperative MELD score cut points for predicting late death as greater than 13.8 (area under the curve = 0.674) and greater than 17 (area under the curve = 0.633), respectively. Patients with a preoperative MELD score of 13.8 or less had significantly greater survival rates than those with a MELD score greater than 13.8 (p = 0.028); patients with a postoperative MELD score of 17 of less had significantly greater survival rates than those with a MELD score greater than 17 (p < 0.001). Multivariate parametric hazard analysis identified postoperative peak creatinine level as a statistically significant predictor of death (relative risk, 1.8; p = 0.01). The 1-, 5-, and 10-year Kaplan-Meier survival rates were 90%, 51%, and 35%, respectively; postoperative mortality rates followed a constant phase model with a hazard of death of 10% per year.

CONCLUSIONS

Cardiac surgical procedures can be performed with acceptable short-term and long-term outcomes in liver transplant recipients. Elevated preoperative and postoperative MELD scores and postoperative peak creatinine level may portend death in this cohort. There is a constant hazard of death of 10% per year.

Cochlear implantation in a patient with combined renal and liver transplantation

OBJECTIVE AND IMPORTANCE

Patients who have undergone solid organ transplantation and continuing immunosuppressant medication are at a higher risk of wound problems and infections following cochlear implantation. This risk is theoretically even further increased in multi-organ transplant recipients due to the increased doses of immunosuppressive medications that these patients are administered.

CLINICAL PRESENTATION AND INTERVENTION

Here, we present the first reported case of successful cochlear implantation in a patient who had previously undergone successful combined liver and kidney transplant. She had no significant complications from the surgery and had good audiological outcomes 3 months post-operatively.

CONCLUSION

As we continue our advances in the use of cochlear implant technology, our report adds to the growing evidence of its benefits in transplant recipients. However, there are important pre- and peri-operative considerations in this group of patients which can improve safety and outcome.

Surgical outcomes after cardiac surgery in liver transplant recipients

OBJECTIVE

This was a single-center retrospective study to assess the surgical outcomes and predictors of mortality of liver transplant recipients undergoing cardiac surgery.

METHODS

From 2000 to 2010, 61 patients with a functioning liver allograft underwent cardiac surgery. The mean interval between liver transplantation and cardiac surgery was 5.4 ± 4.4 years. Of the 61 patients, 33 (54%) were in Child-Pugh class A and 28 in class B. The preoperative and postoperative data were reviewed.

RESULTS

The overall in-hospital mortality was 6.6%. The survival rate was 82.4% ± 5.1% at 1 year and 50.2% ± 8.2% at 5 years. Cox regression analysis identified preoperative encephalopathy (odds ratio, 5.2; 95% confidence interval, 1.8-15.5; P = .003) and pulmonary hypertension (odds ratio, 3.5; 95% confidence interval, 1.3-9.4; P = .045) as independent predictors of late mortality. The preoperative Model for End-Stage Liver Disease (MELD) scores of patients who died in-hospital or late postoperatively were significantly greater statistically than the scores of the others (in-hospital death, 23.7 ± 7.8 vs 13.1 ± 4.5, P < .001; late death, 15.2 ± 6.1 vs 12.3 ± 4.1, P = .038). The Youden index identified an optimal MELD score cutoff value of 13.5 (sensitivity, 56.0%; specificity, 67.6%). Kaplan-Meier survival analysis successfully demonstrated that the survival rate of the MELD score less than 13.5 (MELD <13.5) group was significantly greater than that of the MELD >13.5 group (MELD <13.5 group, 93.8% ± 4.2% at 1 year and 52.4% ± 11.8% at 5 years; MELD >13.5 group, 66.9% ± 9.6% at 1 year and 46.1% ± 11.1% at 5 years; P = .027). In contrast, the survival rate when stratified by Child-Pugh class (class A vs B) was not significantly different.

CONCLUSIONS

Cardiac surgery in the liver allograft recipients was associated with acceptable surgical outcomes. Preoperative encephalopathy and pulmonary hypertension were independent predictors of late mortality. The cutoff value of 13.5 in the MELD score might be useful for predicting surgical mortality in cardiac surgery.

Cardiac surgical outcomes in abdominal solid organ (renal and hepatic) transplant recipients: a case-matched study

OBJECTIVES

This study aims to investigate the outcomes of cardiac surgery in patients with abdominal solid organ transplants and to compare them with the case-matched population undergoing cardiac surgery.

METHODS

Data from all transplant recipients abdominal solid organ transplant (ASOT) N = 36 (30 renal and 6 hepatic) who underwent cardiac surgery in a single centre during the period from January 1997 to December 2010 were collected from hospital transplant registries and the cardiac database. The transplant recipients were case matched (CM) with 104 patients in terms of the variables of age, sex and the type of cardiac surgery. Follow-up data were obtained from medical records and by a set of questionnaire through telephonic interviews.

RESULTS

Follow-up times were 4.5 ± 3.2 and 3.9 ± 3.2 years in the transplant and CM groups, respectively. Follow-up in the transplant group was 100%. There was no 30-day mortality in the transplant group. Thirty-day combined major morbidities were 9% in the matched group vs 11% in the transplant patients (P = 0.6). Median length of stay was 6 days (inter-quartile range, IQR 5.9) for ASOT vs 5 days (IQR 4.6) for CM (P < 0.01). New dialysis was 8.3% in transplant patients compared with 0.96% in the matched population, while infection was 16.66 vs 0.42% in the CM cohort. There was no allograft failure/dysfunction at the time of death or latest follow-up. Late deaths were 8 of 36 (22%) in ASOT vs 6 of 104 (6%) in CM. Infection (63%) was the most frequent major cause of death in transplant patients. One-, 2-, 5- and 10-year survivals for ASOT vs CM were 94, 88, 80, 59 vs 99, 99, 91, 85%, respectively. Multivariate predictors of mortality were increasing age (hazard ratio, HR 1.1, 95% confidence interval, CI 1.04-1.18; P = 0.003) and solid organ transplantation (HR 3.44, CI 1.19-9.98; P = 0.023).

CONCLUSIONS

Cardiac surgery can be performed in patients with abdominal solid organ tranpslant recipients with acceptable early morbidity and mortality. However, long-term survival in transplant patients is poor. Infection remains the most common cause of death.

Survival of kidney transplantation patients in the United States after cardiac valve replacement

BACKGROUND

Few published studies address the survival of kidney transplantation patients after valve surgery, and none address relative outcomes related to tissue versus nontissue prosthesis. This study aimed to assess survival of US kidney transplantation patients after cardiac valve replacement and to compare associations of valve selection.

METHODS AND RESULTS

Of 1 698 706 patients in the US Renal Data System database, we identified 1335 kidney transplantation patients hospitalized in 1991 to 2004 for cardiac valve replacement. Survival was estimated by the Kaplan-Meier method; independent predictors of death were examined in a comorbidity-adjusted (by Charlson and propensity score) Cox model. Of the cohort, 17% were 0 to 44 years of age, 50% were 45 to 64 years of age, 28% were 65 to 74 years of age, and 5% were > or =75 years of age; 78% were white; 63% were men; and 20% had kidney failure caused by diabetes mellitus. Of 369 patients (28%) who received tissue valves, 75% had aortic valve replacement, 20% had mitral valve replacement, and 5% had both. Use of tissue valves increased from 13% in 1991 to 1995 to 38% in 2000 to 2004. Age, diabetes mellitus, and combined aortic and mitral valve replacement were the strongest predictors of all-cause mortality. In-hospital mortality was 14.0% overall, 11.4% for tissue-valve patients, and 15.0% for nontissue-valve patients (P=0.09). Two-year survival estimates were 61.5% for tissue-valve and 59.5% for nontissue-valve patients (P=0.30). The adjusted hazard ratio of death for tissue- versus nontissue-valve patients was 0.83 (95% confidence interval, 0.70 to 0.99).

CONCLUSIONS

Renal transplantation patients requiring valve replacement have high mortality rates ( approximately 20%/y). These data suggest minimally reduced mortality risk for patients receiving tissue versus nontissue valves.

Heart Valve Operations in Solid Organ Recipients: An 18-Year Single-Center Experience

BACKGROUND

We retrospectively analyzed the outcome of heart valve operations in solid organ recipients, who were referred for operation to our institution.

METHODS

Over an 18-year period, 23 heart (group 1) and 16 renal (group 2) transplant recipients in New York Heart Association (NYHA) classes III and IV underwent valve operation. The mean interval from the time of transplantation to cardiac surgery was 77.9 months with a mean follow-up time of 34.6 months in group 1 and 87.2 months with a mean follow-up time of 39.2 months in group 2.

RESULTS

Group 1 underwent tricuspid valve replacement (n=12), tricuspid valve reconstruction (n=7), aortic valve replacement (AVR, n=3), and mitral valve replacement (MVR, n=1). In group 2, mechanical valve replacement was performed in 14 patients (9 AVR, 3 MVR, 2 AVR and MVR) and tricuspid or mitral valve reconstruction in two patients. There was no operative death. During hospitalization, multiorgan failure due to sepsis was the main cause of mortality (2 in both groups). In the mean follow-up period of 41.2 months, there were four late non-cardiac-related deaths in group 1. Currently 29 surviving transplant recipients (16 heart, 69.6% and 13 renal, 81.3%) are in NYHA classes I and II.

CONCLUSION

In heart and renal recipients, valve operations can be performed effectively and safely with acceptable mortality, low cardiac morbidity, and excellent clinical results, although infection is the most serious complication.

Excellent results of cardiac surgery in patients with previous liver transplantation

Cardiovascular diseases requiring surgical therapy in patients with prior liver transplantation are rare. Little is known about the outcome of patients with liver allograft undergoing cardiac surgery. Herein we report our experience in this patient population with an emphasis on operative outcomes and mid-term survival. Between January 1998 and December 2004, 12 patients (mean +/- standard deviation age 68 +/- 9 years, 7 [58%] male) with previous liver transplantation who underwent cardiac surgery were identified. Main outcome measures were hospital mortality, postoperative complications, allograft function, and long-term survival. There was no in-hospital mortality. Three major complications (25%) occurred, including 1 each (8%) of respiratory failure, renal failure, and biliary leakage. All complications were resolved by the time of discharge. Allograft dysfunction determined by an increase of liver function parameters was noticed in 4 (33%) and recovered before discharge. The average length of stay in intensive care unit was 72 +/- 45 hours, and the mean length of stay in hospital was 22 +/- 17 days. One- and 5-year survival was 91% +/- 8% and 67% +/- 14%, respectively. Cardiac surgery can be performed safely in liver transplant recipients with extremely low mortality and acceptable morbidities. Allograft dysfunction is a common finding, but it is transient, with early functional recovery. Five-year survival of liver recipients undergoing cardiac procedures is similar to that of the general population undergoing cardiac surgery. Our data suggest that these patients should be considered for cardiac surgery in reference centers with expertise in complex cardiac procedures and perioperative management of these highly specific patients.