Amyotrophic lateral sclerosis (ALS), a novel rare cause of elevated plasma troponin T levels.

In this article, we report on a patient with chronic and modestly elevated plasma troponin T (TnT) levels and frequent hospitalizations following the first admission until his death one year later. The patient was initially admitted for dyspnea and discharged from hospital with a diagnosis of non-ST elevation acute myocardial infarction (AMI). Coronary angiography and echocardiography were normal, but the patient received the (false) diagnosis of AMI at two further admissions, based purely on elevated TnT. Shortly thereafter, severe respiratory failure with restrictive-type spirometry pattern became the predominant clinical symptom, with constantly elevated TnT levels at frequent re-admissions. Due to inconsistent follow-up by primarily junior and non-specialist staff at a number of different wards, pulmonary function tests and previous smoking history were mis-interpreted as typical of chronic obstructive pulmonary disease (COPD). The patient received standard COPD treatment without any improvement. After a year of gradually worsening respiratory failure and repeated hospitalizations, thorough assessment by a pulmonologist and neurologist established the final diagnosis of amyotrophic lateral sclerosis (ALS). The patient died shortly thereafter. While progressive respiratory failure is well-known to determine morbidity and mortality in patients with ALS, chronically elevated TnT levels in the absence of coronary artery disease have, to our best knowledge, not been described so far. We suggest that chronic myocardial hypoxia due to ALS-related hypoxic respiratory failure was the most likely underlying etiology for the elevated TnT levels seen here but other mechanism such as immune-mediated myocardial injury cannot be excluded.