"Ultra-sensitive" cardiac troponins: Requirements for effective implementation in clinical practice

Area of Science:

• Clinical Chemistry
• Cardiology
• Biomarker Analysis

Background:

• Cardiac troponin measurement is crucial for diagnosing acute coronary syndrome (ACS), particularly non-ST elevation myocardial infarction (NSTEMI).
• Analytical performance metrics like limit of detection (LoD) and 99th percentile are key for troponin immunoassays.
• High-sensitivity (HS) assays have significantly lower LoDs and detect troponin in over 50% of healthy individuals.

Purpose of the Study:

• To review current commercially available high-sensitivity and ultra-sensitive cardiac troponin assays.
• To discuss the implications of enhanced analytical sensitivity on diagnostic algorithms for suspected ACS.
• To highlight the need for new diagnostic strategies and validated, assay-specific cut-offs.

Main Methods:

• Review of analytical characteristics of commercially available cardiac troponin immunoassays.
• Comparison of first-generation assays with current HS and ultra-sensitive techniques.
• Discussion of diagnostic paradigms and potential new strategies.

Main Results:

• HS assays exhibit over 100-fold lower LoD compared to earlier methods.
• Ultra-sensitive assays can measure cardiac troponin in the vast majority of healthy subjects.
• Current diagnostic approaches may be challenged by the increased sensitivity of new assays.

Conclusions:

• The advent of ultra-sensitive cardiac troponin assays necessitates the development and validation of new diagnostic algorithms.
• Assay-specific cut-offs are crucial for accurate risk stratification in patients with suspected ACS.
• Further multicenter studies are required to validate novel diagnostic strategies using advanced troponin assays.