Incidence and Mortality of Emergency General Surgery Conditions Among Solid Organ Transplant Recipients in Ontario, Canada: A Population-based Analysis.

BACKGROUND: Emergency general surgery (EGS) conditions and their outcomes are perceived to be disproportionately high among solid organ transplant recipients (SOTRs). However, this has not been adequately investigated at a population level. We characterized the incidence and mortality of EGS conditions among SOTRs compared with nontransplant patients. METHODS: Data were collected through linked administrative population-based databases in Ontario, Canada. We included all adult SOTRs (kidney, liver, heart, and lung) who underwent transplantation between 2002 and 2017. We then identified posttransplantation emergency department visits for EGS conditions (appendicitis, cholecystitis, choledocolithiasis, perforated diverticulitis, incarcerated/strangulated hernias, small bowel obstruction, and perforated peptic ulcer). Age-, sex-, and year-standardized incidence rate ratios (SIRRs) were generated. Logistic regression models were used to evaluate association between transplantation status and 30 d mortality after adjusting for demographics, year, and comorbidities. RESULTS: Ten thousand seventy-three SOTRs and 12 608 135 persons were analyzed. SOTRs developed 881 EGS conditions (non-SOTRs: 552 194 events). The incidence of all EGS conditions among SOTR was significantly higher compared with the nontransplant patients [SIRR 3.56 (95% confidence interval [CI] 3.32-3.82)], even among those with high Aggregated Diagnosis Groups scores ( > 10) [SIRR 2.76 (95% CI 2.53-3.00)]. SOTRs were 1.4 times more likely to die at 30 d [adjusted odds ratio 1.44 (95% CI 1.08-1.91)] after an EGS event compared with nontransplant patients, predominantly amongst lung transplant recipients [adjusted odds ratio 3.28 (95% CI 1.72-6.24)]. CONCLUSIONS: The incidence of EGS conditions is significantly higher in SOTRs even after stratifying by comorbidity burden. This is of particular importance as SOTRs also have a higher likelihood of death after an EGS condition, especially lung transplant recipients.

Time-Varying Proteinuria and the Risk of Cardiovascular Disease and Graft Failure in Kidney Transplant Recipients.

Introduction: Proteinuria is recognized as an independent risk factor for cardiovascular disease in kidney transplant recipients, but previous studies have not considered the impact of changes in urine protein over time. Research Question and Design: We used time-dependent, multivariable Cox proportional hazards models in this observational cohort study of adult kidney transplant recipients to evaluate whether proteinuria measured by dipstick on random spot urine samples starting from 1-month post-transplant was associated with the risk of major adverse cardiac events and graft loss. Results: A total of 144 major adverse cardiac events, defined as acute myocardial infarction, cerebrovascular accident, revascularization, or all-cause mortality, were observed in 1106 patients over 5728.7 person-years. Any level of proteinuria greater or equal to trace resulted in a two-fold increase in the risk of major adverse cardiac events (hazard ratio 2.00 [95% confidence interval 1.41, 2.84]). This relationship was not found to be dose-dependent (hazard ratios of 2.98, 1.76, 1.63, and 1.54 for trace, 1+, 2+, and 3+ urine protein, respectively). There was an increased risk of graft failure with greater urine protein concentration (hazard ratios 2.22, 2.85, 6.41, and 19.71 for trace, 1+, 2+, and 3+, respectively). Conclusion: Urine protein is associated with major adverse cardiac events and graft loss in kidney transplant recipients. The role of interventions to reduce proteinuria on decreasing the risk of adverse cardiovascular and graft outcomes in kidney transplant recipients requires further study.

Early postoperative acute myocardial infarction in kidney transplant recipients: A nested case-control study.

INTRODUCTION: The epidemiology of early acute myocardial infarctions after kidney transplantation has not been well characterized. This study sought to examine the incidence, risk factors, and clinical outcomes of early acute myocardial infarctions or EAMI in kidney transplant recipients. METHODS: A total of 1976 patients who underwent kidney transplantation at our center from Jan 1, 2000, to Sept 30, 2016, were included. A nested case-control design was used to study EAMI risk factors using a conditional logistic regression model. A Cox proportional hazards model was used to assess the association of EAMI with death-censored graft failure, death with graft function, and total graft failure. RESULTS: Seventy four patients had an EAMI within 3 months post-transplant. Based on univariable analyses, risk factors for EAMI included age and recipient history of diabetes mellitus or coronary artery disease. After adjustment, recipient history of coronary artery disease was the only independent predictor for EAMI (OR 3.76, p < .001). Patients who experienced EAMI were more likely to experience death-censored graft failure, death with graft function, and total graft failure. CONCLUSION: While the incidence of EAMI in kidney transplant recipients is relatively low, these data show that EAMI has profound long-term effects on morbidity and mortality.

Elevated Risk of Cancer After Solid Organ Transplant in Childhood: A Population-based Cohort Study.

BACKGROUND: Cancer risk is elevated among adult transplant recipients, but there is limited data regarding long-term cancer risk and mortality in pediatric recipients. METHODS: We conducted a population-based retrospective cohort study in Ontario, Canada. We included pediatric recipients of solid organ transplants at the Hospital for Sick Children, Toronto, from 1991 to 2014, and compared rates of new cancers and cancer-specific mortality to nontransplanted Ontario children born in the same year. We constructed standard and time-dependent Cox proportional hazards models accounting for competing risk of death. RESULTS: A total of 951 recipients (kidney, n = 400; liver, n = 283; heart, n = 218; lung, n = 36; multiorgan/small bowel, n = 14) were compared with 5.3 million general population children. Mean (SD) age was 8.2 (6.4) years; 50% were male. Over a mean (SD) follow-up of 10.8 (7.1) years, cumulative incidence of cancer was 20% in recipients and 1.2% in the general population (incidence rate ratio, 32.9; 95% confidence interval [CI], 26.6-40.8). Risk was highest in the first year posttransplant (adjusted hazard ratio [aHR],176; 95% CI, 117-264), but remained elevated beyond 10 years (aHR, 10.8; 95% CI, 6.3-18.6). Lymphoproliferative disorders were predominant (77%); however, solid cancers (renal, sarcomas, genital, thyroid) were seen. Recipients of lung or multiorgan transplants were at highest risk. Cancer-specific mortality was also higher among recipients (HR, 93.1; 95% CI, 59.6-145.2). CONCLUSIONS: Childhood transplant recipients have a 30 times greater cancer incidence versus the general population. Further investigation is needed to guide screening strategies in this at-risk population.

Living donor age and kidney transplant outcomes: an assessment of risk across the age continuum.

Detailed data on living donor age, and its interplay with recipient age, in predicting allograft and recipient outcomes are wanting. We used the Scientific Registry of Transplant Recipients (2000-2009, n = 49 589) to assess the effect of living donor age on delayed graft function (DGF), total graft failure, death-censored graft failure, death with graft function, and graft failure with death as a competing risk using logistic and Cox proportional hazards models. Potential nonlinear associations were modeled using fractional polynomial functions. There was a significant 1.87-fold increase in the adjusted odds of DGF in the oldest versus youngest age groups. The 10-year adjusted hazard ratios (HR) for total graft failure, death-censored graft failure, and death with graft function increased in a nonlinear fashion across the range of living donor age studied. Graft failure was most accentuated in the youngest recipient age groups in competing risk models. Adjustment for renal function at 6- and 12-months post-transplant markedly attenuated the association between living donor age and graft/patient outcomes. Our findings confirm the important influence of living donor age on transplant outcomes and provide detailed estimates of risk across the living donor age continuum.