Diagnostic performance of Cardiac Troponin influenced by Age, finds study

The diagnostic performance of cardiac troponin is influenced by Age as per a recent study. It showed reduced specificity and positive predictive value in older patients. The study was published in the journal Circulation.  

The 99th centile of cardiac troponin is generally used as the diagnostic threshold for myocardial infarction. But age is the strongest influencer for troponin concentrations. Researchers conducted a secondary analysis of a multicenter trial to assess the diagnostic performance of cardiac troponin in aged patients presenting with suspected myocardial infarction.

The diagnostic accuracy of high-sensitivity cardiac troponin I at presentation for the diagnosis of type 1, type 2, or type 4b myocardial infarction across 3 age groups was done on consecutive patients with suspected myocardial infarction using guideline-recommended sex-specific and age-adjusted 99th centile thresholds. The three age groups were <50, 50–74, and ≥75 years. 

Key findings: 

• In 46 435 consecutive patients aged 18 to 108 years with a mean age of 61 years. 
• There were 12 379 participants in <50 years, 22 380 participants from 50 to 74, and 11 676 participants in ≥75years age groups. 
• Of the total 5216 (11%) had a diagnosis of myocardial infarction. 
• In patients <50, 50 to 74, and ≥75 age groups, the sensitivity of the guideline-recommended threshold was similar at 79.2%, 80.6%, and 81.6%, respectively.
• The specificity decreased with advancing age from 98.3% to 95.5%, and 82.6%.
• The use of age-adjusted 99th centile thresholds improved the specificity (91.3% vs 82.6%) and positive predictive value (59.3% vs 51.5%) for myocardial infarction in patients ≥75 years but failed to prevent the decrease in either parameter with increasing age. This resulted in a marked reduction in sensitivity compared with the use of the guideline-recommended threshold (55.9% versus 81.6%). 

Thus, the researchers concluded that the diagnostic performance of cardiac troponin is altered by the age of the individuals for guideline-recommended or age-adjusted 99th centiles. They also recommended individualizing the diagnostic approaches rather than adjusting the binary thresholds in the aging population. 

For full reading: 10.1161/CIRCULATIONAHA.122.059994

Lowry MTH, Doudesis D, Wereski R, et al. Influence of Age on the Diagnosis of Myocardial Infarction [published online ahead of print, 2022 Sep 15]. Circulation. 2022;101161CIRCULATIONAHA122059994.