Introduction
Myocarditis is an inflammatory disease of the myocardium characterised by the degeneration and necrosis of cardiac muscle cells. Reference Batra and Lewis1 Its clinical presentation varies widely, ranging from mild, nonspecific symptoms resembling an upper respiratory tract infection to fulminant cardiogenic shock that can be fatal. Despite advances in diagnostic techniques and intensive care management, myocarditis continues to be associated with substantial morbidity and mortality. It accounts for approximately 5% of sudden cardiac deaths in children, with autopsy studies reporting a prevalence ranging from 0.12% to 12%. Reference Di Filippo2–Reference Doolan, Langlois and Semsarian4 Most myocarditis-related deaths occur within the first year of life, yet data on factors determining the need for paediatric intensive care unit (PICU) admission and mortality remain limited. Reference Azhar5,Reference Akgül, Er and Ulusoy6
A definitive diagnosis of myocarditis is established through endomyocardial biopsy (EMB) and/or cardiac magnetic resonance imaging (MRI). However, in clinical practice, elevated serum cardiac biomarkers and echocardiographic evidence of left ventricular systolic dysfunction are often sufficient to support a presumptive diagnosis. Reference Baughman7 Accordingly, cases confirmed by EMB or cardiac MRI are categorised as definite myocarditis, whereas clinically suspected or possible myocarditis is used to describe cases in which invasive or imaging confirmation cannot be obtained. Reference Law, Lal and Chen8 Myocarditis typically presents in its acute form (acute myocarditis, AM), but it can also manifest as acute fulminant, chronic active, or chronic persistent subtypes. Reference Lieberman, Hutchins, Herskowitz, Rose and Baughman9 Acute fulminant myocarditis (AFM) is characterised by cardiogenic shock or severe arrhythmias accompanied by haemodynamic instability. Reference Mccarthy, Boehmer, Hruban, Hutchins and Baughman10 The arrhythmias most commonly reported in AFM include prolonged QTc interval, first-degree atrioventricular block, premature atrial contractions, supraventricular tachycardia, and ventricular arrhythmias. Reference Şengül, Arslan and Duras11
The optimal management of AM in children has not yet been fully established. Intravenous immunoglobulin (IVIG) is widely regarded as a safe and frequently used first-line therapy; however, evidence regarding its efficacy and outcomes remains limited. Reference Ghelani, Spaeder, Pastor, Spurney and Klugman12 In cases unresponsive to medical therapy or complicated by multi-organ failure, extracorporeal membrane oxygenation (ECMO) may be considered as a rescue intervention.
The present multicentre study aimed to evaluate the demographic characteristics, admission features, therapeutic interventions, and clinical outcomes of children with clinically suspected AM admitted to PICUs. Additionally, we sought to identify the factors associated with mortality and to analyse the determinants of hospital and PICU length of stay (LOS) in this case population.
Materials and methods
Study design and participants
This multicentre retrospective study was conducted over an 18-month period, from March 2022 to October 2023, across 11 PICUs in Istanbul, Türkiye. Ten of these units were general PICUs caring for critically ill children, and one was a dedicated paediatric cardiac ICU. Ethical approval was obtained from the institutional ethics committee of the coordinating centre, and the study was performed in accordance with the principles of the Declaration of Helsinki. Due to its retrospective nature, written informed consent from patients or guardians was not required. Inclusion criteria were as follows: (1) age between 1 month and 18 years, (2) acute-onset heart failure, (3) elevated cardiac biomarker levels, (4) reduced left ventricular ejection fraction (LVEF) on echocardiography, and (5) absence of a prior diagnosis of congenital or acquired heart disease, primary cardiomyopathy (including genetic aetiologies), metabolic disorders, or autoimmune diseases such as Kawasaki disease. Patients who did not meet the inclusion criteria, had a secondary diagnosis of myocarditis, or had incomplete medical records were excluded. Additionally, patients diagnosed with multisystem inflammatory syndrome in children (MIS-C) or myocarditis temporally associated with SARS-CoV-2 infection were excluded. Multisystem inflammatory syndrome in children was ruled out based on clinical findings, laboratory evidence of systemic inflammation, and SARS-CoV-2 PCR and/or serological testing results, when available.
Patient identification was based on International Classification of Diseases, Tenth Revision (ICD-10) diagnostic codes. The study was designed and reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology statement (Supplementary File 1).
The diagnosis of AM was supported by clinical presentation, elevated cardiac biomarkers, electrocardiographic abnormalities, and reduced LVEF on echocardiography. Reference Sagar, Liu and Cooper13 Acute-onset heart failure was defined as a sudden impairment of cardiac function leading to the inability of the heart to meet the oxygen and metabolic demands of peripheral tissues. Reference Dickstein, Cohen-Solal and Filippatos14 Acute fulminant myocarditis was defined as acute heart failure accompanied by signs of shock—such as weak pulses, prolonged capillary refill time, oliguria, metabolic acidosis, or hypotension—or by the presence of arrhythmia. Reference Jayashree, Patil and Benakatti15 Cardiogenic shock was defined as a state of decreased cardiac output resulting in tissue hypoxia and life-threatening organ perfusion abnormalities. Reference Van Diepen, Katz and Albert16
Cardiac biomarkers measured in this study included troponin T and N-terminal pro-brain natriuretic peptide (NT-proBNP). Serum troponin T concentrations were determined using the Elecsys Troponin T hs assay (Roche Diagnostics), and NT-proBNP concentrations were analysed using the Elecsys NT-proBNP II assay (Roche Diagnostics), both based on monoclonal antibodies targeting glycosylated regions of the respective molecules. Reference ranges were 0–14 ng/L for troponin and 0–125 ng/L for NT-proBNP, with values above these thresholds considered elevated. The detection limits were 3–10,000 ng/L for troponin and 5–35,000 ng/L for NT-proBNP. The detection limit for NT-proBNP could be up to 70,000 ng/L, but the upper limit in the study was determined as 35,000 ng/L (pg/mL equals ng/L).
Left ventricular ejection fraction was measured via echocardiography using Simpson’s biplane method. Examinations were performed using Philips AffinitiCVx and GE Vivid S5 systems by experienced paediatric cardiologists. A LVEF value < 55% was considered reduced.
Data collection
Collected data included demographic characteristics (age, sex, presence of chronic disease), initial symptoms, physical examination findings, vital signs at admission (peripheral oxygen saturation-Spo2, heart rate, respiratory rate, systolic and diastolic blood pressure), hospital and PICU LOS, and intensive care scoring systems (Paediatric Risk of Mortality-3 [PRISM-3] and Paediatric Logistic Organ Dysfunction-2 [PELOD-2]). In addition, initial and peak cardiac biomarker levels recorded during the ICU stay, electrocardiographic abnormalities at presentation, initial and final LVEF values, chest X-ray findings, type and duration of respiratory support, medical treatments (inotropes and IVIG), and the use and outcomes of ECMO were extracted from patient charts. Hypoxia was defined as SpO2< 92% on room air. Hypotension was defined according to age-specific systolic blood pressure thresholds: < 70 mmHg for <1 year, <70 + 2 × age (years) mmHg for 1–10 years, and <90 mmHg for >10 years. Patients were categorised into survivor and non-survivor groups based on clinical outcomes during PICU follow-up. The non-survivor group consisted of patients who died during intensive care hospitalisation. N-terminal pro-brain natriuretic peptide values exceeding the laboratory upper reporting limit were recorded as the upper limit value for analysis.
Statistical analysis
Statistical analyses were performed using IBM SPSS Statistics for Windows, version 29.0 (IBM Corp., Armonk, NY, USA). Data distribution was assessed for normality prior to analysis. Continuous variables were expressed as mean ± standard deviation (SD) or median and interquartile range (IQR), as appropriate. Categorical variables were summarised as frequencies and percentages. Group comparisons between survivors and non-survivors were conducted using the Mann–Whitney U test for continuous variables and Pearson’s chi-square or Fisher’s exact test for categorical variables. Correlation analyses were performed using Spearman’s rho coefficient, with correlation strength classified as negligible (0.00–0.10), weak (0.10–0.30), moderate (0.30–0.50), strong (0.50–0.70), very strong (0.70–0.90), or nearly perfect (0.90–1.00). Before linear regression analysis, the assumptions of linearity, normality of residuals, and homoscedasticity were assessed. A p-value< 0.05 was considered statistically significant for all analyses.
Results
The characteristics of the cases included in the study according to the inclusion and exclusion criteria are summarised in the flow diagram (Figure 1). A total of 90 cases diagnosed with AM were included in the study. The PICU mortality rate was 21.1%. Mortality was defined as death occurring during the PICU stay. All deaths occurred during PICU hospitalisation, and no deaths were observed after discharge from the PICU. All non-survivor patients had been monitored in the PICU for at least 24 hours. Cardiac MRI was performed in 21 cases (23.3%), and biopsy was performed in two cases (2.2%). A higher proportion of non-survivors were female compared with survivors (78.9% vs. 54.9%, p = 0.048). Although the median age was lower among non-survivors (18 vs. 33 months), the difference was not statistically significant (p = 0.084). The prevalence of chronic disease was significantly higher in the non-survivor group (31.6% vs. 11.3%, p = 0.030).
Study Flowchart.
Comparison between survivors and non-survivors
Comparisons of demographic characteristics, presenting symptoms, clinical findings, hospital and PICU course, laboratory parameters, electrocardiographic and echocardiographic findings, chest radiographic results, respiratory support modalities, and therapeutic interventions between survivors and non-survivors are presented in Table 1. Non-survivors presented more frequently with exercise intolerance and vomiting (p = 0.027 and p = 0.008, respectively). They also had higher rates of hypoxia, hypotension, and cardiogenic shock at admission (p = 0.005, p = 0.004, and p = 0.011, respectively). Although the hospital stay was longer among survivors (p = 0.004), PRISM-3 and PELOD-2 scores were significantly higher in non-survivors (p < 0.001 for both). No statistically significant differences were found in initial or peak troponin levels between the two groups; however, both initial and peak NT-proBNP levels were markedly higher in non-survivors (p = 0.015 and p = 0.018, respectively). Non-survivors also exhibited higher rates of sinus tachycardia and arrhythmia (p = 0.047 and p = 0.024, respectively), as well as significantly lower initial and final LVEF values compared with survivors (p = 0.010 and p < 0.001, respectively). Regarding respiratory support, survivors were more frequently managed without oxygen or ventilatory support (p = 0.011), whereas non-survivors more often required invasive mechanical ventilation (IMV) (p < 0.001). The use of vasoactive and inotropic agents was substantially higher in non-survivors (p < 0.001 for adrenaline and noradrenaline; p = 0.008 for dopamine and levosimendan; p = 0.007 for dobutamine).
Comparison of key characteristics for survivors vs. nonsurvivors
*Pearson chi-squared test and Fisher’s exact test was used, significant p values were indicated as bold and starred.
☨Mann–Whitney U test was used, significant p values were indicated as bold and starred.
CMP = cardiomyopathy; COT = continuous oxygen therapy; ECMO = extracorporeal membrane oxygenation; LVEF = Left ventricular ejection fraction; HFNC = High flow nasal cannula; IMV = invasive mechanical ventilation; IVIG = intravenous immunoglobulin; NIV = non-invasive mechanical ventilation; NT-proBNP = N-terminal-pro brain natriuretic peptide; PELOD = paediatric logistic organ dysfunction score; PICU = paediatric intensive care unit; PRISM-3 = pediatric risk of mortality-3.
Characteristics of acute fulminant myocarditis cases
The clinical and laboratory characteristics of cases with AFM are summarised in Table 2.
The characteristics of the cases with acute fulminant miyocarditis
ECMO = extracorporeal membrane oxygenation; LVEF = left ventricular ejection fraction; HFNC = high flow nasal cannula; IMV = invasive mechanical ventilation; IVIG = intravenous immunoglobulin; NIV =non-invasive mechanical ventilation; NT-proBNP = N-terminal-pro brain natriuretic peptide; PELOD = paediatric logistic organ dysfunction score; PICU = paediatric intensive care unit; PRISM-3 = pediatric risk of mortality-3.
Correlation analysis for length of stay
The correlations between hospital and PICU LOS and clinical parameters among survivors are presented in Table 3. There was a weak negative correlation between age and PICU LOS (r = −0.255, p = 0.032). The PRISM-3 score showed a weak positive correlation with both hospital and PICU LOS (r = 0.284, p = 0.016; r = 0.300, p = 0.011, respectively). The PELOD-2 score demonstrated a moderate positive correlation with hospital LOS and a strong positive correlation with PICU LOS (r = 0.485, p < 0.001; r = 0.552, p < 0.001, respectively). Initial and peak troponin levels were positively correlated with hospital LOS (r = 0.290, p = 0.014; r = 0.253, p = 0.033, respectively) and with PICU LOS (r = 0.400, p < 0.001; r = 0.253, p = 0.033, respectively). Initial NT-proBNP levels showed no association with hospital LOS but demonstrated a weak positive correlation with PICU LOS (r = 0.290, p = 0.014). Peak NT-proBNP levels exhibited a moderate positive correlation with both hospital and PICU LOS (r = 0.306, p = 0.015; r = 0.388, p = 0.002, respectively). Initial LVEF values were negatively correlated with hospital and PICU LOS (r = −0.247, p = 0.044; r = −0.260, p = 0.034, respectively).
Correlation analysis for factors affecting hospital and PICU duration of stay in survivors
LVEF = Left ventricular ejection fraction; NT-proBNP = N-terminal-pro brain natriuretic peptide; PELOD = paediatric logistic organ dysfunction score; PICU = paediatric intensive care unit; PRISM-3 = Pediatric risk of mortality-3.
r: Correlation coefficient.
p: Significance.
Predictors of mortality
In the multivariate logistic regression analysis, variables entered into the model included adrenaline use, noradrenaline use, levosimendan use, IMV, hypoxia, hypotension, cardiogenic shock, sex, and the presence of a chronic underlying disease. Adrenaline administration (adjusted OR 8.43, 95% CI 1.40–50.92, p = 0.020) and the presence of a chronic underlying disease (adjusted OR 6.65, 95% CI 1.05–42.30, p = 0.045) were independently associated with mortality. Other variables, including noradrenaline and levosimendan use, IMV, hypoxia, hypotension, cardiogenic shock, and sex, were not independently associated with mortality after adjustment (Table 4).
Multivariate logistic regression analysis for factors independently associated with mortality in patients with acute myocarditis
Dependent variable: mortality (1 = yes, 0 = no). Binary variables coded as 1 = present, 0 = absent. Female sex reference category: male.
*p < 0.05 statistically significant.
Predictors of length of paediatric intensive care unit stay
A multiple linear regression analysis was conducted to identify predictors of PICU LOS among survivors (Table 5). Higher initial troponin levels (B = 0.005, p = 0.006) and younger age (B = −0.062, p = 0.004) were independently associated with longer PICU stays. Although the PELOD-2 score showed a borderline positive association (p = 0.061), initial NT-proBNP and LVEF values were not significant predictors.
Linear regression analysis for factors influencing PICU length of stay in survivors with acute myocarditis
Dependent variable: Paediatric Intensive Care Unit (PICU) length of stay (days). Independent variables: PELOD-2 score, initial troponin, initial NT-proBNP, initial LVEF, and age.
*p < 0.05 indicates statistical significance.
LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal-pro brain natriuretic peptide; PELOD = Paediatric logistic organ dysfunction score; PICU = Paediatric intensive care unit.
Discussion
In the present multicentre study, 60% of patients with AM were female, and the predominant presenting symptoms and physical examination findings were respiratory in nature. This distribution contrasts with previous reports indicating that AM occurs more frequently in males and that gastrointestinal symptoms are the most common presenting features. Reference Towbin, Lowe and Colan17,Reference Zhuang, Shi and Gao18 This difference in gender distribution may be related to the cardioprotective effects of female hormones, which have been reported to modulate inflammatory and immune responses in the myocardium. Reference Schwartz, Sartini and Huber19 In our study, ethnic and regional differences in disease presentation and referral patterns may have contributed to this variation. Although the median age did not differ significantly between survivors and non-survivors, we observed that younger age was inversely correlated with PICU LOS among survivors (r = −0.255, p = 0.032). This association likely reflects the increased vulnerability and need for prolonged supportive care among younger children due to their limited physiological reserve and developmental immaturity. In addition, the significantly higher prevalence of underlying chronic diseases among non-survivors (p = 0.030) suggests that comorbid conditions exacerbate disease severity and increase mortality risk in paediatric myocarditis.
Hypoxia, hypotension, and tachycardia at presentation were significantly more frequent in non-survivors, consistent with the findings of Hsiao et al., who identified hypotension as a key predictor of mortality in paediatric myocarditis. Reference Hsiao, Hsia and Wu20 The higher prevalence of haemodynamic instability among non-survivors was accompanied by greater use of respiratory support and vasoactive/inotropic therapy. The rate of IMV in our cohort (44.4%) was slightly higher than in previous reports (approximately 37.5%), Reference Klugman, Berger, Sable, He, Khandelwal and Slonim21 likely due to the predominance of respiratory symptoms at presentation in our patient population. Among vasoactive/inotropic drugs, adrenaline use was found to be an independent predictor of mortality (Table 4).
Accurate prediction of mortality risk is critical in the management of PICU patients. The PRISM-3 and PELOD-2 scoring systems, routinely used across participating centres, serve as validated tools for assessing disease severity and mortality risk. Both scores are derived from the most abnormal physiological and laboratory parameters recorded within the first 24 hours of PICU admission; higher scores correspond to increased mortality probability. Reference Pollack, Patel and Ruttimann22 As expected, both PRISM-3 and PELOD-2 scores were significantly higher in the non-survivor group (p < 0.001). Previous studies comparing PRISM-3, PELOD-2, and the Pediatric Index of Mortality-3 (PIM-3) have reported variable performance. One study found that PRISM-3 had superior discriminative power for mortality prediction compared with the PIM-3, Reference Rahmatinejad, Rahmatinejad and Sezavar23 whereas Lee et al., in a cohort of 945 patients, demonstrated that PELOD-2 outperformed the PIM-3 in predicting observed mortality. Reference Lee, Lee and Kim24 In our study, PRISM-3 showed a weak positive correlation with both hospital and PICU LOS, while PELOD-2 exhibited a moderate correlation with hospital LOS and a strong correlation with PICU LOS. These findings suggest that the PELOD-2 score may be more useful than PRISM-3 in estimating intensive care resource utilisation and predicting LOS among children with AM.
Troponin and NT-proBNP were the most commonly used cardiac biomarkers across all participating centres. No statistically significant differences in troponin levels were observed between survivors and non-survivors, either at presentation or at peak levels during PICU follow-up (p = 0.894 and p = 0.059, respectively). Although troponin is a sensitive indicator of myocardial injury, it does not always correlate with the clinical severity of AM. Reference Butts, Boyle and Deshpande25 In our study, however, higher initial and peak troponin levels among survivors were associated with longer hospital and PICU stays, suggesting that greater myocardial damage at admission may predict a more prolonged recovery phase rather than mortality itself. In contrast, NT-proBNP—an established biomarker of impaired cardiac function and left ventricular failure Reference Mangat, Carter and Riley26 —was significantly higher in non-survivors, both at presentation and at any time during the PICU stay (p = 0.015 and p = 0.018, respectively). Elevated NT-proBNP reflects increased ventricular wall stress and neurohormonal activation, providing valuable prognostic information in paediatric myocarditis. Lee et al. demonstrated that elevated NT-proBNP levels were associated with the need for intensive care and increased mortality risk, Reference Lee, Lee and Kim27 while Abrar et al. similarly reported that higher NT-proBNP concentrations were correlated with higher mortality. Reference Abrar, Ansari, Mittal and Kushwaha28 In our analysis, initial NT-proBNP levels were not predictive of hospital LOS, but higher values were associated with prolonged PICU LOS. Moreover, as peak NT-proBNP levels increased during the ICU course, both hospital and PICU LOS extended proportionally. These findings suggest that serial NT-proBNP measurement may serve as a useful marker of ongoing haemodynamic stress and delayed cardiac recovery in children with AM.
When evaluating other parameters influencing LOS, a clear relationship was observed between reduced initial LVEF and prolonged PICU stay. Both initial and follow-up LVEF values were significantly lower in non-survivors compared with survivors (p = 0.010 and p < 0.001, respectively). Although AM does not have pathognomonic echocardiographic findings, systolic dysfunction and reduced ejection fraction are frequently encountered. Reference Felker, Boehmer and Hruban29 In line with previous studies, our results confirm that severely depressed LVEF is a strong predictor of poor outcomes in paediatric myocarditis. Reference Sachdeva, Song and Dham30
Forty-three patients (47.8%) in our cohort were diagnosed with AFM presenting with cardiogenic shock (Table 2). Among these, ten cases (23.3%) exhibited arrhythmia at admission. Although the true incidence of AFM in the paediatric population remains unclear, previous studies have reported rates ranging from 10% to 38% of all myocarditis cases. Reference Al-Biltagi, Issa, Hagar, Abdel-Hafez and Aziz31,Reference McCarthy, Boehmer and Hruban32 The higher rate in our study likely reflects the inclusion of a specific patient population—namely, those requiring PICU admission—and may also explain our relatively elevated mortality rate (21.1%) compared with previous studies. Reference Ghelani, Spaeder, Pastor, Spurney and Klugman12,Reference Klugman, Berger, Sable, He, Khandelwal and Slonim21,Reference Wu, Wu and Wang33 The predominance of respiratory system–related symptoms at presentation may have delayed the recognition of myocarditis and the initiation of appropriate therapies, potentially contributing to higher mortality. Zhao et al., in their analysis of 79 paediatric AFM cases, identified severe myocardial injury, metabolic acidosis, hypoxia, marked inflammatory response, LV systolic dysfunction, multiorgan failure, and respiratory failure as major determinants of poor outcomes. Reference Zhao, Da, Yang, Xu and Qi34 Our findings are consistent with these observations, emphasising that early identification and aggressive management of AFM are crucial for improving survival in this critically ill population.
Most cases of AM develop following a viral infection that triggers immune activation; both direct viral injury and immune-mediated inflammation contribute to myocardial damage and disease progression. Reference Kim, Yoo and Kil35,Reference Komuro, Ueda and Kaneko36 Intravenous immunoglobulin has been used in AM treatment due to its antiviral and anti-inflammatory properties, yet its therapeutic efficacy remains controversial. In adults with AFM, IVIG administration has been associated with improved left ventricular function and reduced arrhythmia incidence. Reference Yu, Wang and Ma37 Similarly, a meta-analysis of 13 studies reported that IVIG therapy was linked to better clinical outcomes in both adult and paediatric patients with AM and AFM. Reference Huang, Sun and Su38 However, other investigations have failed to demonstrate survival benefits from IVIG therapy in either age group. Reference McNamara, Holubkov and Starling39,Reference El-Saiedi40 In our cohort, 67.8% of patients received IVIG therapy, with a higher utilisation rate among survivors (71.8%) compared to non-survivors (52.6%). The treatment protocol across participating centres consisted of a total IVIG dose of 2 g/kg administered over two days. A previous study found no significant difference in mortality between patients treated with methylprednisolone (MPZ) and IVIG; however, those who received MPZ had shorter hospital stays. Reference Khan, Hussain, Ilyas, Yousafzai, Khan and Ali41
For patients with AM unresponsive to medical therapy or those developing multiorgan failure, ECMO serves as a life-saving intervention. In cases of AFM, ECMO indications include cardiogenic shock requiring high-dose inotropic support, refractory arrhythmias, cardiac arrest, and multiorgan dysfunction Reference Lin, Li and Hsieh42,Reference Wu, Lin, Yang, Wu and Chen43 Among the 11 participating centres, five provided active ECMO support. In our study, ECMO was utilised in 8.9% of patients, with a survival rate of 50%. Complications were observed in three patients, consistent with previously reported outcomes in similar critically ill populations.
This study has several limitations. Its retrospective design introduces inherent biases, and the diagnosis of AM was based primarily on clinical and laboratory criteria rather than routine confirmation by EMB or cardiac MRI. Although cardiac MRI was performed in 21 patients and biopsy confirmation was available in two, none of the participating centres performed autopsies for deceased patients, limiting pathological confirmation in fatal cases. Despite efforts to exclude primary cardiomyopathy and genetic aetiologies, inadvertent inclusion of such cases cannot be completely ruled out. MIS-C–related myocarditis was excluded; therefore, the results may not be generalisable to this specific population. Although linear regression was used for PICU LOS analysis, LOS data are typically right-skewed, which represents a potential limitation of this modelling approach. N-terminal pro-brain natriuretic peptide values were capped at the laboratory upper reporting limit, which may have limited the assessment of extreme biomarker elevations. Because of the multicentre design, centre-level differences in clinical practice patterns and resource availability, including ECMO capability, were not adjusted for and may have influenced outcomes. Finally, since patients needed to survive long enough to receive the complete course of IVIG, the higher utilisation rate observed among survivors may reflect a timing bias rather than a true treatment effect.
Conclusion
In conclusion, among children with AM admitted to the PICU, female sex and the presence of underlying chronic disease were associated with higher mortality risk. Younger age and lower initial LVEF were related to prolonged PICU LOS. Increasing intensive care scores and cardiac biomarker levels correlated positively with both hospital and PICU LOS, whereas admission NT-proBNP values were not predictive of hospital stay duration. The strongest association was observed between PELOD-2 scores and PICU LOS, suggesting that PELOD-2 at admission may serve as a useful tool for estimating the expected duration of intensive care in children with AM.
Supplementary material
The supplementary material for this article can be found at https://doi.org/10.1017/S1047951126113080.
Acknowledgements
We thank Oyku Tosun (Associate Professor of Pediatric Cardiology, Istanbul Medeniyet University, Faculty of Medicine, Goztepe Prof Dr Suleyman Yalcın City Hospital, Department of Pediatric Cardiology); Helen Bornaun (Professor of Pediatric Cardiology, University of Health Sciences Türkiye, Kanuni Sultan Suleyman Training and Research Hospital, Department of Pediatric Cardiology); Mehmet Bedir Akyol (Associate Professor of Pediatric Cardiology, University of Health Sciences Türkiye, Bakirkoy Dr Sadi Konuk Training and Research Hospital, Department of Pediatric Cardiology); Mehmet Turan Basunlu (Pediatric Cardiologist, Istanbul Medipol University, Bagcilar Mega Hospital, Department of Pediatric Cardiology); Saliha Oner (Professor of Pediatric Cardiology, University of Health Sciences Türkiye, Umraniye Training and Research Hospital, Department of Pediatric Cardiology); Doruk Ozbingol (Pediatric Cardiologist, Istanbul University, Faculty of Medicine, Department of Pediatric Cardiology); Canan Yolcu (Pediatric Cardiologist, University of Health Sciences Türkiye, Haseki Training and Research Hospital, Department of Pediatric Cardiology); Tugcin Bora Polat (Professor of Pediatric Cardiology, Acibadem Mehmet Ali Aydinlar University, Atakent Hospital, Department of Pediatric Cardiology); Ahmet Irdem (Associate Professor of Pediatric Cardiology, University of Health Sciences Türkiye, Prof Dr Cemil Tascioglu City Hospital, Department of Pediatric Cardiology); Sertac Hanedan Onan (Associate Professor of Pediatric Cardiology, University of Health Sciences Türkiye, Bagcilar Training and Research Hospital, Department of Pediatric Cardiology).
Financial support
This research received no specific grant from any funding agency, commercial or not-for-profit.
Competing interests
The authors declare that there is no conflict of interest.
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