From the Guidelines
Chronic troponin I elevation refers to a persistent and elevated level of troponin I, a cardiac biomarker, in the blood, typically exceeding the 99th percentile of a normal reference population, for a duration of more than 7-14 days 1. This condition may be associated with various underlying cardiac and non-cardiac pathologies, including:
- Chronic heart failure
- Coronary artery disease
- Chronic kidney disease
- Hypertrophic cardiomyopathy
- Inflammatory diseases, such as myocarditis
- Infiltrative diseases, such as amyloidosis
- Severe pulmonary embolism or pulmonary hypertension
- Sepsis and critically ill patients
- Severe acute neurological diseases, such as stroke or subarachnoid hemorrhage
- Strenuous exercise
In some cases, certain medications, such as statins and beta-blockers, may also contribute to chronic troponin I elevation, although the exact mechanisms and durations of therapy are still being investigated 1. The distinction of acute vs. chronic myocardial injury lies in both the magnitude of the cTn concentration and its temporality of change, with chronic elevation often associated with apoptosis, cardiomyocyte turnover, myocardial strain, and subclinical plaque rupture 1.
The release of cTn is agnostic to the cause of myocardial damage, and numerous studies have detected elevated cTn concentrations in otherwise healthy individuals following physical exertion 1. The utility of routine assessment of serum troponin levels in patients with acute or chronic heart failure, as well as the appropriate diagnostic and therapeutic approaches to elevated serum troponin levels in non-ACS setting remains to be determined 1.
It is essential to note that elevated troponin levels have been associated with poor long-term prognosis, and the demonstration of a rising and/or falling pattern is needed to distinguish acute- from chronic elevations in cTn concentrations that are associated with structural heart disease 1.
Key Points
- Chronic troponin I elevation is a persistent and elevated level of troponin I in the blood, exceeding the 99th percentile of a normal reference population, for a duration of more than 7-14 days.
- This condition may be associated with various underlying cardiac and non-cardiac pathologies.
- The distinction of acute vs. chronic myocardial injury lies in both the magnitude of the cTn concentration and its temporality of change.
- Elevated troponin levels have been associated with poor long-term prognosis.
- The demonstration of a rising and/or falling pattern is needed to distinguish acute- from chronic elevations in cTn concentrations that are associated with structural heart disease.
Causes of Chronic Troponin I Elevation
- Chronic heart failure
- Coronary artery disease
- Chronic kidney disease
- Hypertrophic cardiomyopathy
- Inflammatory diseases, such as myocarditis
- Infiltrative diseases, such as amyloidosis
- Severe pulmonary embolism or pulmonary hypertension
- Sepsis and critically ill patients
- Severe acute neurological diseases, such as stroke or subarachnoid hemorrhage
- Strenuous exercise
- Certain medications, such as statins and beta-blockers
Clinical Implications
- Elevated troponin levels have been associated with poor long-term prognosis.
- The demonstration of a rising and/or falling pattern is needed to distinguish acute- from chronic elevations in cTn concentrations that are associated with structural heart disease.
- The utility of routine assessment of serum troponin levels in patients with acute or chronic heart failure, as well as the appropriate diagnostic and therapeutic approaches to elevated serum troponin levels in non-ACS setting remains to be determined.
From the Research
Definition and Causes of Chronic Troponin Elevation
- Chronic troponin elevation refers to the persistent increase in cardiac troponin levels in the blood, which can be detected using sensitive assays 2, 3, 4, 5, 6.
- This condition can occur in patients with chronic kidney disease, coronary artery disease, and other cardiac and non-cardiac conditions 2, 3, 4, 5, 6.
- The causes of chronic troponin elevation include myocardial injury, apoptosis, and cell turnover, as well as oxygen supply-demand mismatch 4, 5, 6.
Clinical Significance and Diagnosis
- Chronic troponin elevation is a marker for poor outcomes, including increased rates of mortality 4, 5.
- The diagnosis of chronic troponin elevation requires consideration of the clinical context, patient symptoms, electrocardiogram, and ultrasound 4.
- Cardiac troponin I concentrations can be correlated with myocardial tissue characteristics assessed by T1 mapping, a cardiovascular magnetic resonance technique 6.
Associated Conditions and Mechanisms
- Chronic troponin elevation can be associated with impaired left ventricular function, as indicated by elevated N-terminal pro-brain natriuretic peptide (NT-proBNP) levels 5.
- Diffuse edema or fibrosis scattered in normal myocardium may be associated with chronic troponin release 6.
- The mechanisms causing chronic troponin elevation may be prognostically less harmful in patients treated with an early invasive strategy 5.
Key Findings and Associations
- Persistent cardiac troponin I elevation occurs frequently late after an acute coronary syndrome, and is predicted by NT-proBNP levels, male sex, and early invasive strategy 5.
- Cardiac troponin I concentrations correlate with native T1 and extracellular volume (ECV) values, and are independently associated with native T1 and ventricular mass index 6.