Increased cardiac troponin levels in acute dyspnoea represents a mortality risk even in those without an acute myocardial infarction
Acute dyspnoea is a common complaint within an emergency department (ED). Dyspnoea also commonly presents in nearly two-thirds of patients experiencing an acute myocardial infarction. Consequently prompt patient assessment to identify the underlying cause of the dyspnoea is vital. High-sensitivity cardiac troponin T (CTT) can quickly assess patients with chest pain to rule out an MI. Nevertheless, elevated cardiac troponin T levels can also occur in those experiencing chest pain without an MI.
In the current study, researchers wanted to explore the role of CTT in ED patients presenting with acute dyspnoea that was not due to an acute MI. Adult patients with acute dyspnoea were included and CTT levels measured together with their clinical history. CTT levels were divided into three levels: <15, 15-100 and > 100 µg/l. An analysis provided the 3-month relative risk of mortality with adjustment to models for a patient’s clinical history.
Cardiac troponin and 3-month mortality risk
A sample of 1001 patients had usable data. With CTT levels < 15 set as the reference point, a CTT level between 15 and 100 gave rise to a more than 3-fold higher mortality risk (Hazard ratio, HR = 3.68 (95% CI 1.72 – 7.84). The mortality risk was even higher with levels above 100 µg/l (HR = 10.523, 95% CI 4.46 – 24.80).
Patients with higher cardiac troponin levels were generally older, had a higher number of co-morbidities and more severe symptoms. The researchers felt that the data highlighted the value of CTT as an important risk factor in acute dyspnoea without a cardiac cause.