Prevalence of false positive troponin I in elderly patients with rhabdomyolysis

Rhabdomyolysis following Nuss Procedure: A Prospective Study in Children

INTRODUCTION

 Postoperative rhabdomyolysis (RML) has been documented after several surgical procedures in adults. Musculoskeletal remodeling after Nuss procedure for pectus excavatum (PE) could cause RML. We evaluated the incidence of RML after Nuss procedure in children.

METHODS

 This study was a prospective study from 2018 to 2021. We enrolled all otherwise healthy patients who underwent PE correction with only one bar. Studied variables included demographic and clinical data, duration of surgery, complications, and length of hospitalization. The patients included underwent serial measurements of serum creatine kinase (CK), troponin I, N terminal pro B-type natriuretic peptide (NT-proBNP), serum creatinine, urea, and glomerular filtration rate at 6 and 48 hours postoperatively, and hospital discharge.

RESULTS

 Forty-six patients met criteria (40 males/6 females), with a mean age of 15.1 ± 1.4 years. Mean duration of surgery was 74 ± 28 minutes, and length of hospitalization was 4.6 ± 1.6 days. RML was diagnosed in 30.4% of patients at 6 hours, 91.3% at 48 hours, and 21.7% at hospital discharge. Mean preoperative CK value was 181.1 ± 141.6 IU/L, and postoperative values were 863.3 ± 302.6 IU/L at 6 hours, 1,675.2 ± 561 IU/L at 48 hours, and 850 ± 683.7 IU/L at hospital discharge, with statistically significant differences (p = 0.001). High-sensitivity troponin I and NT-proBNP levels increased significantly during the postoperative time (p = 0.001). Renal function remained stable (p = 0.55).

CONCLUSION

 Nuss technique produces RML without kidney injury in healthy patients. This knowledge should be considered for patients at increased risk of developing acute kidney injury and other complications.

Troponin elevation in the setting of exercise-induced rhabdomyolysis in an athletic teenager

Troponin levels are often obtained when chest pain is evaluated in the paediatric emergency department. Elevations in troponin levels can be due to different causes, and it is important to fully understand all of these possible causes to help streamline further evaluation and therapy. We present the case of a teenager who had two episodes of troponin elevation in the setting of rhabdomyolysis.

Clinicopathological complexity in the application of the universal definition of myocardial infarction

A universal definition of myocardial infarction (UDMI) has been established, periodically updated, and refined over the past twenty years. The primary purpose of the UDMI is to bring uniformity and accuracy to clinical diagnosis. Herein, a review and analysis of the UDMI is presented with emphasis on clinicopathological correlation. Determination of the presence of myocardial injury is based on the detection of abnormal serum cardiac biomarkers, particularly cardiac troponin (cTn), and in the current fourth iteration of the UDMI, high sensitivity (hs)-cTn. Differentiation of myocardial infarction from other causes of myocardial injury requires the documentation of clinical evidence of myocardial ischemia. In this review, difficulties in applying the UDMI in actual practice are discussed, based on the experience and perspective of those of us who face these problems as part of our own practice of pathology. The complexity in application of the UDMI is highlighted by the presentation of five illustrative cases involving the differential diagnosis of myocardial injury and myocardial infarction due to atherothrombotic and nonatherothrombotic coronary artery disease. The cases include myocardial infarction due to severe coronary atherosclerosis, supply-demand mismatch, coronary artery dissection associated with an eosinophilic coronary periarteritis, and coronary thromboembolism, and a case with a differential diagnosis of myocarditis and myocardial infarction. These cases illustrate how pathological findings can contribute to more accurate application of the UDMI and how, when critically applied, the UDMI can be used to better characterize myocardial infarcts in clinical practice.