Long-term patient and allograft outcomes of renal transplant recipients undergoing cardiac surgery

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.

Successful rescue of renal transplantation with cardiac arrest after electrical storm: A case report

RATIONALE

Most patients with end-stage chronic kidney disease are associated with complications such as renal hypertension, renal anemia, hyperkalemia, water-sodium retention, and disorders of acid-base balance after long-term renal replacement therapy, which can lead to increased cardiac burden, some degree of myocardial damage, and finally progress to arrhythmia and heart failure. These are the main reasons why patients with chronic kidney disease are prone to cardiovascular events after renal transplantation.

PATIENT CONCERNS

We report a case of sudden onset of ventricular fibrillation on the postoperative second day, with repeated electrical storm accompanied by cardiac arrest during resuscitation, a very long cardiopulmonary resuscitation (CPR) process of 5 hours and 14 minutes, and >20 cycles of cardiac defibrillation.

DIAGNOSES

According to the patient history and resuscitation process, a diagnosis of ES with cardiac arrest after renal transplantation was formulated.

INTERVENTION

According to the American Heart Association guidelines for CPR and cardiovascular emergencies, resuscitation measures such as CPR, tracheal intubation, electric defibrillation, symptomatic medication, etc. were performed on the patient.

OUTCOMES

Finally, the patient was successfully resuscitated, after which the patient had stable respiratory circulation and no neurological complications. To our knowledge, this is the only reported case in which a patient survived with good neurologic outcomes after a resuscitation that lasted as long as 5 hours and 14 minutes.

LESSONS

This case of adequate resuscitation can provide experience and a basis for CPR of patients with in-hospital complications of cardiovascular events for a long time.

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.

Analysis of the frequency of single nucleotide polymorphisms in cytokine genes in patients with New Onset Diabetes After Transplant

New Onset Diabetes After Transplantation (NODAT) is a serious metabolic complication. While β-cell dysfunction is considered the main contributing factor in the development of NODAT, the precise pathogenesis is not well understood. Cytokines are thought to be involved in the inflammation of islet β-cells in diabetes; however, few studies have investigated this hypothesis in NODAT. A total of 309 kidney transplant recipients (KTRs) were included in this study. An association between kidney transplants, and the development of diabetes after transplant (NODAT) was investigated. Comparison was made between KTRs who develop diabetes (NODAT cases) or did not develop diabetes (control), using key cytokines, IL-6 G (− 174)C, macrophage mediator; IL-4 C (− 490)T, T helper (Th)-2 cytokine profile initiator; Th-1 cytokine profile initiator interferon-γ T (+ 874) A gene and TGF β1 C (+ 869) T gene polymorphisms were investigated. The genes were amplified using well-established polymerase chain reaction (PCR) techniques in our laboratory. Compared to the AA and AT genotypes of interferon gamma (IFNG), there was a strong association between the TT genotype of IFNG and NODAT kidney transplant recipients (KTRs) versus non-NODAT KTRs (p = 0.005). The AA genotype of IFNG was found to be predominant in the control group (p = 0.004). Also, significant variations of IL6 G (− 174) C, IL-4 C (− 590) T, interferon-γ T (+ 874) A gene and transforming growth factor β1 C (+ 869) T may contribute to NODAT. Our data is consistent with theTh-1/T-reg pathway of immunity. Further larger pan Arab studies are required to confirm our findings.

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.

Cardiac valve operations after solid organ transplantation: A single-center experience

OBJECTIVE

Cardiac valve operations in patients who have undergone solid organ transplantation (ie, kidney, liver, pancreas, heart, and lung) pose unique challenges due to patient comorbidities and to the need for immunosuppressive therapy. The aim of this retrospective study was to present our experience with patients with solid-organ transplant who had cardiac valve operation at the time or after transplantation.

METHODS

Records of patients who had undergone cardiac valve operations after solid organ transplantation between January 1998 and January 2019 were retrospectively reviewed. Follow-up amounted to a median of 51 months (interquartile range, 5-88 months).

RESULTS

Among the 14,465 patients who underwent treatment for a cardiac valvular pathology during the study period, 127 patients (0.9%) had undergone a solid organ transplantation (kidney: n = 9 [76%]; liver: n = 12 [9%]; pancreas: n = 4 [3%]; heart: n = 16 [13%]; lung: n = 9 [7%]). Postoperatively, 14 patients (11%) underwent rethoracotomy for bleeding and 24 patients (19%) required new dialysis treatment. Twenty-five patients (20%) died in-hospital. Postoperative course was worse in patients operated for endocarditis or undergoing concomitant transplantation and valve surgery. Overall survival was 59%, 47%, and 40%, but survival conditioned to hospital discharge was 73%, 58%, and 50% at 5-, 10-, and 15-year follow-up, respectively. Freedom from major valve-related events amounted to 77%, 56%, and 46%, respectively.

CONCLUSIONS

Although the high prevalence of postoperative complications, especially in patients with endocarditis or concomitant transplantation and valve surgery, survival conditioned to hospital discharge was satisfactory in patients undergoing valve surgery after solid organ transplantation.

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.

Comparison of interventional and surgical myocardial revascularization in kidney transplant recipients - A single-centre retrospective analysis

Background

Kidney transplant recipients (KTR) reflect a high-risk population for coronary artery disease (CAD). CAD is the most common cause for morbidity and mortality in this population. However, only few data are available on the favourable revascularization strategy for these patients as they were often excluded from studies and not mentioned in guidelines.

Methods

This retrospective single-centre study includes patients with a history of kidney transplantation undergoing myocardial revascularization for multivessel or left main CAD by either percutaneous coronary intervention (PCI, n = 27 patients) or coronary artery bypass grafting (CABG, n = 24 patients) at University Hospital Frankfurt, Germany, between 2005 and 2015.

Results

In-hospital mortality was higher in the CABG group (20.8% vs. 14.8% PCI group; p = 0.45). In Kaplan-Meier analysis, one-year-survival showed better outcome in the PCI group (85.2% vs. 75%). After four years, outcome was comparable between both strategies (PCI 66.5% vs. CABG 70.8%; log-rank p = 0.94).

Acute kidney injury (AKI), classified by Acute Kidney Injury Network, was observed more frequently after CABG (58.3% vs. 18.5%; p < 0.01). After one year, graft survival was 95.7% in the PCI group and 94.1% in the CABG group. Four year follow-up showed comparable graft survival in both groups (76.8% PCI and 77.0% CABG; p = 0.78).

Conclusion

In this retrospective single-centre study of KTR requiring myocardial revascularization, PCI seems to be superior to CABG with regard to in-hospital mortality, acute kidney injury and one-year-survival. To optimise treatment of these high-risk patients, larger-scaled studies are urgently warranted.

Outcomes of Cardiac Surgery in Patients With Previous Solid Organ Transplantation (Kidney, Liver, and Pancreas)

A growing number of solid organ transplant survivors require surgery for cardiac disease. We examined the effect of having a previous transplant on outcomes after cardiac surgery in these patients from a population-based perspective. Of 1,709,735 patients who underwent coronary artery bypass grafting, valve, or thoracic aorta surgery from 2004 to 2008 in the Nationwide Inpatient Sample, 3,535 patients (0.21%) had a previous organ transplant (2,712 kidney, 738 liver, 300 pancreas). Multivariate logistic regression analysis and propensity score matching were used to determine the effect of a previous solid organ transplant on outcomes. In-hospital mortality rate was 7% for patients who underwent transplantation versus 4% for patients who did not undergo transplantation (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.16 to 2.38). Patients who underwent transplantation were at an increased risk for acute renal failure (OR 1.62, CI 1.36 to 1.94) and blood transfusions (OR 1.63, CI 1.36 to 1.95). Median length of stay was longer (10 vs 9 days), with greater median total charges ($111,362 vs $102,221; both p <0.001). Occurrence of stroke, gastrointestinal complication, infection, and pneumonia was similar between groups. In conclusion, previous solid organ transplantation is an incremental risk factor for postoperative mortality after cardiac surgery. Renal protective strategies and bleeding control should be stressed to mitigate complications.

Valve-sparing aortic root reconstruction in patient with prior renal transplantation

We describe a David operation in a 62-year-old renal transplant recipient with valsalva aneurysm and concomitant aortic insufficiency. The risk of postoperative infection seemed significant because he was receiving immunosuppressive therapy; thus, David operation was performed. He recovered uneventfully. David operation appears to be an attractive alternative in transplant recipients.