Prevalence, Predictors, and Prognostic Value of Renal Dysfunction in Adults With Congenital Heart Disease

Incidence, risk factors, and outcomes of acute kidney injury after pediatric cardiac surgery: a prospective multicenter study

OBJECTIVE

To determine the incidence, severity, and risk factors of acute kidney injury in children undergoing cardiac surgery for congenital heart defects.

DESIGN

Prospective observational multicenter cohort study.

SETTING

Three pediatric intensive care units at academic centers.

PATIENTS

Three hundred eleven children between the ages of 1 month and 18 yrs undergoing pediatric cardiac surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Acute kidney injury was defined as a ≥50% increase in serum creatinine from the preoperative value. Secondary outcomes were length of mechanical ventilation, length of intensive care unit and hospital stays, acute dialysis, and in-hospital mortality. The cohort had an average age of 3.8 yrs and was 45% women and mostly white (82%). One-third had prior cardiothoracic surgery, 91% of the surgeries were elective, and almost all patients required cardiopulmonary bypass. Acute kidney injury occurred in 42% (130 patients) within 3 days after surgery. Children ≥2 yrs old and <13 yrs old had a 72% lower likelihood of acute kidney injury (adjusted odds ratio: 0.28, 95% confidence interval: 0.16, 0.48), and patients 13 yrs and older had 70% lower likelihood of acute kidney injury (adjusted odds ratio: 0.30, 95% confidence interval: 0.10, 0.88) compared to patients <2 yrs old. Longer cardiopulmonary bypass time was linearly and independently associated with acute kidney injury. The development of acute kidney injury was independently associated with prolonged ventilation and with increased length of hospital stay.

CONCLUSIONS

Acute kidney injury is common after pediatric cardiac surgery and is associated with prolonged mechanical ventilation and increased hospital stay. Cardiopulmonary bypass time and age were independently associated with acute kidney injury risk. Cardiopulmonary bypass time may be a marker for case complexity.

Approach to managing children with heart disease for noncardiac surgery

Congenital heart disease is the commonest birth defect, and advances in modern medicine mean 90% of these children now survive to adulthood. Therefore, many children present to their local hospital requiring general anesthesia for common childhood conditions. They pose a challenge for anesthesia because perioperative morbidity and mortality is greater compared with other children. It is impossible to prescribe a formula for anesthetizing children with heart disease because of the complexity of heart defects and the variety of noncardiac surgery. There is also a lack of high-quality data of efficacy of one anesthetic technique over another. Much data come from case series or isolated case reports. In a rapidly advancing field such as cardiac surgery, studies of long-term complications may be out of date by the time they are published, limiting applicability of the results. Because of these factors, claims of efficacy and safety of various approaches to managing children with heart disease for noncardiac surgery must be interpreted cautiously. This narrative review aims to present the evidence concerning a range of anesthetic techniques, the long-term complications of congenital heart disease and suggest a physiological and evidence-based approach to managing these children.

Indications for heart transplantation in congenital heart disease

In this review we have looked at indications for cardiac transplantation in congenital heart disease. An outline of the general principles of the use of transplant as a management strategy both as a first line treatment and following other surgical interventions is discussed. We explore the importance of the timing of patient referral and the evaluations undertaken, and how the results of these may vary between patients with congenital heart disease and patients with other causes of end-stage heart failure. The potential complications associated with patients with congenital heart disease need to be both anticipated and managed appropriately by an experienced team. Timing of transplantation in congenital heart disease is difficult to standardize as the group of patients is heterogeneous. We discuss the role and limitations of investigations such as BNP, 6 minute walk, metabolic exercise testing and self estimated physical functioning. We also discuss the suitability for listing. It is clear that congenital heart patients should not be considered to be at uniform high risk of death at transplant. Morbidity varies greatly in the congenital patient population with the failing Fontan circulation having a far higher risk than a failing Mustard circulation. However the underlying issue of imbalance between donor organ supply and demand needs to be addressed as transplant teams are finding themselves in the increasingly difficult situation of supporting growing numbers of patients with a diverse range of pathologies with declining numbers of donor organs.

Heart-kidney interaction: epidemiology of cardiorenal syndromes

Cardiac and kidney diseases are common, increasingly encountered, and often coexist. Recently, the Acute Dialysis Quality Initiative (ADQI) Working Group convened a consensus conference to develop a classification scheme for the CRS and for five discrete subtypes. These CRS subtypes likely share pathophysiologic mechanisms, however, also have distinguishing clinical features, in terms of precipitating events, risk identification, natural history, and outcomes. Knowledge of the epidemiology of heart-kidney interaction stratified by the proposed CRS subtypes is increasingly important for understanding the overall burden of disease for each CRS subtype, along with associated morbidity, mortality, and health resource utilization. Likewise, an understanding of the epidemiology of CRS is necessary for characterizing whether there exists important knowledge gaps and to aid in the design of clinical studies. This paper will provide a summary of the epidemiology of the cardiorenal syndrome and its subtypes.

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Usefulness of natriuretic Peptide levels to predict mortality in adults with congenital heart disease

Neurohormonal activation is prevalent in adults with congenital heart disease, but its relation to outcome remains unknown. B-type natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) were measured prospectively in 49 patients with adult congenital heart disease, who were followed up for a median of 7.9 years (interquartile range 7.7 to 8.2). Cox proportional hazards regression analysis was used to determine the relation of BNP and ANP concentrations to all-cause mortality. The mean age at baseline was 33.9 +/- 11.3 years, and 46.9% of patients were men. Most patients (77.5%) were symptomatic (20.4% had New York Heart Association class III), 10 (20.4%) were cyanotic, and 28 (57.1%) had systemic ventricular dysfunction (moderate or severe in 18.4%). The median concentration of BNP was 52.7 pg/ml (interquartile range 39.1 to 115.4) and of ANP was 47.4 pg/ml (interquartile range 19.7 to 112.8). Of the 49 patients, 11 (22.4%) died during the follow-up period. Both BNP and ANP were strong predictors of mortality (hazard ratio per 100-pg/ml increase 1.80, 95% confidence interval 1.38 to 2.34, p <0.0001; and hazard ratio per 100-pg/ml increase 1.21, 95% confidence interval 1.12 to 1.32, p <0.0001, respectively). A BNP value >78 pg/ml predicted death with a sensitivity of 100% and specificity of 76.3% (area under the curve 0.91, p = 0.0001). An ANP value of >146 pg/ml predicted death with a sensitivity of 72.7% and specificity 94.7% (area under the curve 0.89, p = 0.0001). No patients with a BNP level <78 pg/ml died during the follow-up period. In conclusion, the BNP and ANP levels strongly predicted death in symptomatic ambulatory patients with adult congenital heart disease during mid-term follow-up and could be used as a simple clinical marker for risk stratification in this population.

Improved Survival Among Patients With Eisenmenger Syndrome Receiving Advanced Therapy for Pulmonary Arterial Hypertension

Background— Advanced therapy (AT) for pulmonary arterial hypertension in the context of congenital heart disease (Eisenmenger syndrome) improves pulmonary hemodynamics, functional class, and the 6-minute walk test. We examined the potential effect of AT on survival in this population.

Methods and Results— Data on all Eisenmenger patients attending our center over the past decade were collected. Survival rates were compared between patients on and off AT with the use of a modified version of the Cox model, which treats AT as a time-varying covariate. Baseline differences were adjusted for the use of propensity scores. A total of 229 patients (aged 34.5±12.6 years; 35.4% male) were included. The majority had complex anatomy, and 53.7% were in New York Heart Association class ≥III at baseline assessment. Mean resting saturations were 84.3%. Sixty-eight patients (29.7%) either were on AT or had AT initiated during follow-up. During a median follow-up of 4.0 years, 52 patients died, only 2 of them while on AT. Patients on AT were at a significantly lower risk of death, both unadjusted and after adjustment for baseline clinical differences by propensity score regression adjustment ( C statistic=0.80; hazard ratio, 0.16; 95% confidence interval, 0.04 to 0.71; P =0.015) and propensity score matching (hazard ratio, 0.10; 95% confidence interval, 0.01 to 0.78; P =0.028).

Conclusions— AT for pulmonary arterial hypertension in a contemporary cohort of adults with Eisenmenger syndrome was associated with a lower risk of death. Survival benefits should be considered together with improved hemodynamics and functional class when decisions are made about AT in this population.

Cardio-renal syndromes: report from the consensus conference of the acute dialysis quality initiative

A consensus conference on cardio-renal syndromes (CRS) was held in Venice Italy, in September 2008 under the auspices of the Acute Dialysis Quality Initiative (ADQI). The following topics were matter of discussion after a systematic literature review and the appraisal of the best available evidence: definition/classification system; epidemiology; diagnostic criteria and biomarkers; prevention/protection strategies; management and therapy. The umbrella term CRS was used to identify a disorder of the heart and kidneys whereby acute or chronic dysfunction in one organ may induce acute or chronic dysfunction in the other organ. Different syndromes were identified and classified into five subtypes. Acute CRS (type 1): acute worsening of heart function (AHF–ACS) leading to kidney injury and/or dysfunction. Chronic cardio-renal syndrome (type 2): chronic abnormalities in heart function (CHF-CHD) leading to kidney injury and/or dysfunction. Acute reno-cardiac syndrome (type 3): acute worsening of kidney function (AKI) leading to heart injury and/or dysfunction. Chronic reno-cardiac syndrome (type 4): chronic kidney disease leading to heart injury, disease, and/or dysfunction. Secondary CRS (type 5): systemic conditions leading to simultaneous injury and/or dysfunction of heart and kidney. Consensus statements concerning epidemiology, diagnosis, prevention, and management strategies are discussed in the paper for each of the syndromes.

High prevalence of abnormal glucose metabolism in young adult patients with complex congenital heart disease

BACKGROUND

Abnormal glucose metabolism (AGM) adversely impacts morbidity and mortality in patients with chronic heart failure. No data on AGM in adult patients with congenital heart disease (ACHD) are available.

METHODS

To assess the AGM in ACHD and compare the results with their clinical characteristics, we performed a 75-g oral glucose tolerance test to detect AGM, that is, insulin resistance, impaired glucose tolerance, and diabetes mellitus, in 205 consecutive ACHD (24 +/- 8 years), including 16 unrepaired patients, 67 Fontan patients, 122 postbiventricular (BV) patients, and 27 healthy controls (27 +/- 5 years).

RESULTS

All ACHD groups had a high prevalence of AGM (unrepaired, 43.8%; Fontan, 43.3%; BV, 46.7%; control, 3.7%; P < .001). In the 2 postoperative groups, the Matsuda index was decreased (P < .0001), and greater waist circumference, liver dysfunction, higher plasma renin activity, and diuretic use were associated with AGM. Although male gender was associated with AGM (P < .01), baseline glucose and lipid metabolic variables did not correlate with the 75-g oral glucose tolerance test-induced hyperglycemia (area under the plasma glucose curve [AUC-PG]) in the Fontan patients but did correlate in the BV patients. The AUC-PG correlated inversely with exercise capacity (P < .05) in the 2 postoperative ACHD groups, and the AGM ACHD had a high incidence of future cardiac events (P < .05), especially the Fontan patients with diabetes mellitus (P < .01).

CONCLUSIONS

Complex ACHD have a high prevalence of AGM, and this newly recognized pathophysiology should be considered in managing long-term survivors of complex ACHD.

Anesthesia in adult patients with congenital heart disease

PURPOSE OF REVIEW

Recent advances in prenatal diagnosis, interventional cardiology, pediatric cardiac surgery, anesthesia, and critical care have resulted in an increasing number of adult patients with congenital heart disease (CHD). Most of these patients will require noncardiac surgery thus presenting a new challenge for anesthesiologists. The purpose of this article is to summarize preoperative and intraoperative implications for the anesthesiologist in the noncardiac surgery setting.

RECENT FINDINGS

These patients present with an increased risk of perioperative mortality. One of the most specific recommendations from the American College of Cardiology conference published in 2001 was that adult patients with moderate-to-severe CHD undergoing noncardiac surgery should be referred to an adult CHD center with the consultation of an expert anesthesiologist. However, though most experts agree that grown-up CHD poses an increasing risk for noncardiac surgery, no major study focusing on this topic has yet been performed.

SUMMARY

The number of adult patients with CHD is now superior to the number of children. This is a new challenge for anesthesiologist in the noncardiac surgery settings.

Renal function of patients with a failing Fontan circuit undergoing total cavopulmonary revision surgery

This report characterizes renal dysfunction after total cavopulmonary (TCPC) revision surgery for atriopulmonary Fontan (APF) circulations, a known risk factor for a poor outcome. The perioperative data for 23 consecutively identified patients were reviewed. The preoperative mean glomerular filtration rate (GFR) was 101 +/- 30 ml/min/1.73 m(2), decreasing to 65 +/- 41 ml/min/1.73 m(2) early in the postoperative period. The preoperative GFR was highly correlated with age at APF (r = -0.5; p = 0.024), age at TCPC (r = -0.5; p = 0.01), and mixed venous saturation (r = 0.6; p = 0.01). Three of four patients requiring renal replacement therapy (RRT) died at a median age of 3 months (range, 18 days to 9 months). Determinants of early GFR and RRT were preoperative GFR (p = 0.016) and creatinine (p = 0.035). Younger age at primary Fontan (p = 0.008), higher preoperative mixed venous saturation (p = 0.019), and higher preoperative blood pressure (p = 0.006) independently predicted better GFRs at the latest follow-up evaluation. Renal function declines acutely after TCPC revision, often necessitating RRT. A requirement for RRT marks greater mortality. Higher preoperative creatinine levels identify those at greatest risk.