Cardiomyopathy: a late complication of hemolytic uremic syndrome

Cardiac Manifestation among Children with Hemolytic Uremic Syndrome

OBJECTIVE

The primary objectives of the study were to describe the association between cardiac manifestations and in-hospital mortality among children with hemolytic uremic syndrome.

STUDY DESIGN

Using the Pediatric Health Information System database, this retrospective, multicenter, cohort study identified the first hemolytic uremic syndrome-related inpatient visit among children ≤18 years (years 2004-2018). The frequency of selected cardiac manifestations and mortality rates were calculated. Multivariate analysis identified the association of specific cardiac manifestations and the risk of in-hospital mortality.

RESULTS

Among 3915 patients in the analysis, 238 (6.1%) had cardiac manifestations. A majority of patients (82.8%; n = 197) had 1 cardiac condition and 17.2% (n = 41) had ≥2 cardiac conditions. The most common cardiac conditions was pericardial disease (n = 102), followed by congestive heart failure (n = 46) and cardiomyopathy/myocarditis (n = 34). The percent mortality for patients with 0, 1, or ≥2 cardiac conditions was 2.1%, 17.3%, and 19.5%, respectively. Patients with any cardiac condition had an increased odds of mortality (OR, 9.74; P = .0001). In additional models, the presence of ≥2 cardiac conditions (OR, 9.90; P < .001), cardiac arrest (OR, 38.25; P < .001), or extracorporeal membrane oxygenation deployment (OR, 11.61; P < .001) were associated with increased risk of in-hospital mortality.

CONCLUSIONS

This study identified differences in in-hospital mortality based on the type of cardiac manifestations, with increased risk observed for patients with multiple cardiac involvement, cardiac arrest, and extracorporeal membrane oxygenation deployments.

Dilated cardiomyopathy: A rare and late complication of the hemolytic-uremic syndrome

Hemolytic uremic syndrome (HUS) is a non-exceptional, progressive complication of acute gastroenteritis in children, especially secondary to Escherichia coli infection. It is responsible for significant morbidity and significant mortality (10% of deaths) because of acute renal failure which often complicates it. Dilated cardiomyopathy is a rare but critical extra renal manifestation of the HUS. This article highlights the importance of considering the diagnosis of associated cardiomyopathy in the acute phase of HUS and the following months. A five-year-old boy presented with HUS with acute renal failure requiring peritoneal dialysis for 24 days. No cardiac signs appeared during the acute phase of the disease. After dialysis and normalization of blood pressure, fluid, and electrolyte disturbance, severe dilated cardiomyopathy with cardiac failure appeared three months later without definite etiology. A review of the literature confirmed the rare and severe nature of cardiac lesions occurring in HUS. Dilated cardiomyopathy is a rare but important extra renal manifestation of the HUS and is best demonstrated by echocardiography. A cardiac manifestation should also be screened for in the acute phase of HUS and several months later. <Learning objective: The main message to draw from this case is that despite the rarity of cardiac complications, routine echocardiographic screening of children with hemolytic uremic syndrome should be performed both in the acute phase and during subsequent follow-up even in the absence of clinical signs because of severe prognosis of this complication, and it is therefore the investigation of choice.>.

Postinfectious Hemolytic Uremic Syndrome

Post-infectious hemolytic uremic syndrome (HUS) is caused by specific pathogens in patients with no identifiable HUS-associated genetic mutation or autoantibody. The majority of episodes is due to infections by Shiga toxin (Stx) producing Escherichia coli (STEC). This chapter reviews the epidemiology and pathogenesis of STEC-HUS, including bacterial-derived factors and host responses. STEC disease is characterized by hematological (microangiopathic hemolytic anemia), renal (acute kidney injury) and extrarenal organ involvement. Clinicians should always strive for an etiological diagnosis through the microbiological or molecular identification of Stx-producing bacteria and Stx or, if negative, serological assays. Treatment of STEC-HUS is supportive; more investigations are needed to evaluate the efficacy of putative preventive and therapeutic measures, such as non-phage-inducing antibiotics, volume expansion and anti-complement agents. The outcome of STEC-HUS is generally favorable, but chronic kidney disease, permanent extrarenal, mainly cerebral complication and death (in less than 5 %) occur and long-term follow-up is recommended. The remainder of this chapter highlights rarer forms of (post-infectious) HUS due to S. dysenteriae, S. pneumoniae, influenza A and HIV and discusses potential interactions between these pathogens and the complement system.

Extra-renal manifestations of complement-mediated thrombotic microangiopathies

Thrombotic microangiopathies (TMA) are rare but severe disorders, characterized by endothelial cell activation and thrombus formation leading to hemolytic anemia, thrombocytopenia, and organ failure. Complement over activation in combination with defects in its regulation is described in an increasing number of TMA and if primary for the disease denominated as atypical hemolytic-uremic syndrome. Although TMA predominantly affects the renal microvasculature, extra-renal manifestations are observed in 20% of patients including involvement of the central nerve system, cardiovascular system, lungs, skin, skeletal muscle, and gastrointestinal tract. Prompt diagnosis and treatment initiation are therefore crucial for the prognosis of disease acute phase and the long-term outcome. This review summarizes the available evidence on extra-renal TMA manifestations and discusses the role of acute and chronic complement activation by highlighting its complex interaction with inflammation, coagulation, and endothelial homeostasis.

Myocardial infarction is a complication of factor H-associated atypical HUS

Cardiac complications are frequently seen in thrombotic thrombocytopaenic purpura related to ADAMTS13 deficiency. We describe the case of a 43-year-old woman who was diagnosed with an atypical haemolytic-uraemic syndrome (aHUS) associated with a pathogenic mutation in the factor H gene (C623S). After 15 days of treatment, she suffered a sudden cardiac arrest and died despite intensive resuscitation attempts. She showed only one cardiovascular risk factor, hypercholesterolaemia. Her sudden death was secondary to cardiac infarction related to a coronary thrombotic microangiopathy. This is the first case of aHUS related to a mutation in the factor H gene associated with cardiac microangiopathy. This case emphasizes the need to screen for cardiac complication during the treatment of aHUS.

Cardiac tamponade in diarrhoea-positive haemolytic uraemic syndrome

The spectrum of extra-renal involvement secondary to diarrhoeal (D+) haemolytic uraemic syndrome (HUS) includes neurological, gastrointestinal, hepatic, pancreatic and cardiac complications. Among the cardiac complications, myocardial injury has been more commonly reported with HUS. Literature is scarce on HUS-associated pericardial involvement. We report a HUS-induced significant pericardial effusion that resulted in a cardiac tamponade. We also discuss the diagnostic and therapeutic implications of this complication.

Dilated cardiomyopathy during the course of hemolytic uremic syndrome

A 47-year-old woman presented with severe hemolytic uremic syndrome (HUS) followed by heart failure. An echocardiogram showed an ejection fraction of 20%, and a cardiac catheterization followed by a myocardial histologic evaluation demonstrated dilated cardiomyopathy. Plasma exchange and hemodialysis were performed regularly. The later outcomes of renal function and cardiomyopathy were favorable. A review of the literature confirmed the rare and severe nature of cardiac lesions occurring in the course of HUS. This case indicates the importance of cardiac monitoring in HUS and the need for prolonged support.

Hemolytic-uremic syndrome and myocardial dysfunction in a 9-month-old boy

Cardiovascular dysfunction in patients with hemolytic-uremic syndrome (HUS) may be related to secondary issues such as volume overload, hypertension or electrolyte disturbances including hyperkalemia. Additionally, primary myocardial involvement has been increasingly recognized as a potential comorbid feature of HUS. We report a 9-month-old child with HUS who developed clinical signs of poor myocardial function with depressed myocardial function noted by echocardiography. Supportive care including mechanical ventilation and inotropic agents were necessary for approximately 10 days. Follow-up echocardiography revealed return of normal ventricular function. Previous reports of primary cardiac involvement with HUS have included thrombotic microangiopathy of the coronary vasculature resulting in myocardial ischemia, myocardial infarction or depressed myocardial function, myocarditis, congestive heart failure with dilated cardiomyopathy and pericardial effusion with tamponade. Given the potential for morbidity and mortality during the preoperative period in patients with HUS, anesthesiologists involved in the care of such patients should be aware of the potential for myocardial involvement in this disease process. Preoperatively, the routine evaluation of myocardial function may be indicated.

Influence of CD36 deficiency on heart disease in children

BACKGROUND

The physiological role of the CD36 molecule in pediatric heart disease has not been fully investigated.

METHODS AND RESULTS

The CD36 antigen in platelets and monocytes was measured by flow cytometry in 189 patients with various heart diseases; 15 (7.9%) had a diagnosis of CD36 deficiency (type I: 2[1 boy, 1 girl], type II: 13 [6 boys, 7 girls]). The prevalence in each heart disease was as follows: group A (congenital heart disease) 7.6% (9/118, type II: 9 [6 boys, 3 girls]); group B (myocardial disease) 20.0% (3/15, I: 1 girl, II: 2[1 boy, 1 girl]), group C (Kawasaki disease) 4.9% (2/41, II: 2 [1 boy, 1 girl]), group D (arrhythmia): 6.7% (1/15, I: 1 boy). Three patients in group B had transient myocardial damage, which was thought to be related to abnormal myocardial long-chain fatty acid metabolism.

CONCLUSION

The frequency of CD36 deficiency in childhood heart disease was almost identical to that of healthy individuals. Some patients with CD36 deficiency may be susceptible to myocardial damage in the presence of disadvantageous conditions, such as serious infections or massive steroid therapy.

CD36 deficiency and absent myocardial iodine-123-(R,S)-15-(p-iodophenyl)-3-methylpentadecanoic acid uptake in a girl with cardiomyopathy

A 10-year-old girl presented left ventricular failure 1 month after the onset of hemolytic uremic syndrome (HUS) caused by an Escherichia coli O157 infection and was diagnosed as having dilated cardiomyopathy. Thallium myocardial scintigraphy showed normal perfusion, but no myocardial uptake of iodine-123-( R, S)-15-( p-iodophenyl)-3-methylpentadecanoic acid ((123)I-BMIPP) was observed. We analyzed the CD36 expression in platelets and monocytes by using a flowcytometer, and she turned out to have CD36 deficiency type I.

CONCLUSION

Some patients may be predisposed to myocardial damage in the presence of CD36 deficiency. It is necessary to clarify the etiological significance of the relationship between cardiac impairment and CD36 deficiency in children.