Can ARVC and HOCM Present with Elevated Troponin?
Yes, both arrhythmogenic right ventricular cardiomyopathy (ARVC) and hypertrophic obstructive cardiomyopathy (HOCM) can cause elevated troponin levels, even in the absence of acute coronary syndromes. This represents chronic myocardial injury from ongoing cardiomyocyte damage, not acute myocardial infarction.
Understanding Troponin Elevation in Cardiomyopathies
Troponin is a highly sensitive and specific marker of myocardial cell injury, but it does not indicate the underlying cause of that injury 1. While acute MI is the most common reason for troponin elevation in clinical practice, the guidelines explicitly recognize that many non-ACS cardiac conditions cause troponin release 1.
Key Principle from Guidelines
The 2019 JACC expert panel emphasizes that elevated troponin reflects myocardial injury but does not specify the mechanism 1. To diagnose MI, you need both:
- Elevated troponin with rise/fall pattern
- Clinical evidence of myocardial ischemia (symptoms, ECG changes, imaging evidence of ischemia, or obstructive CAD)
Without ischemic evidence, the diagnosis is myocardial injury, not MI 1.
Troponin Elevation in HOCM
Prevalence and Pattern
In HOCM patients, approximately 25-50% demonstrate elevated high-sensitivity cardiac troponin at rest, even without acute coronary syndromes 2. This represents chronic, low-grade myocardial injury rather than acute ischemia.
Clinical Correlations
Elevated troponin in HOCM correlates with:
- Greater left ventricular hypertrophy and maximum wall thickness 2, 3
- Myocardial fibrosis on cardiac MRI 2
- Elevated filling pressures and reduced exercise capacity 2
- Non-sustained ventricular tachycardia (NSVT) - a critical finding 4, 3, 5
Cardiac troponin I ≥0.0265 ng/mL predicts NSVT occurrence in HOCM 5, and elevated troponin independently associates with ventricular arrhythmias and appropriate ICD shocks 4. This matters because NSVT is an independent risk factor for sudden cardiac death in HOCM.
Prognostic Significance
Troponin levels in HOCM patients:
- Increase progressively with worsening ventricular arrhythmic events 5
- Correlate with growing risk of sudden cardiac death 5
- Decline with disease-modifying therapy (cardiac myosin inhibitors), supporting its role as a biologically responsive marker 2
Troponin Elevation in ARVC
Evidence Base
While the guideline evidence for ARVC is less extensive than for HOCM, research demonstrates that ARVC causes elevated troponin through progressive myocardial replacement with fibrofatty tissue 6.
In a veterinary model (Boxers with ARVC), serum cardiac troponin I was significantly elevated compared to controls, with strong correlations between troponin concentration and both the number of ventricular premature complexes (r=0.78) and the grade of ventricular arrhythmia (r=0.77) 6.
Pathophysiology
ARVC is characterized by:
- Loss of myocytes with fatty or fibrofatty replacement 7
- Segmental or diffuse wall thinning
- Frequent left ventricular involvement
- Association with myocarditis 7
This ongoing myocyte loss releases troponin chronically, similar to the mechanism in HOCM.
Clinical Approach When You Encounter This
Differential Diagnosis Framework
When you see elevated troponin in a patient, the 2025 SIRM/SIC consensus and 2019 JACC guidelines provide this algorithm 8, 1:
First, assess for acute coronary syndrome:
- Ischemic chest pain characteristics
- ECG changes (ST-segment depression/elevation, new T-wave inversions)
- Rise/fall pattern on serial troponins (3-6 hours apart)
If ACS criteria not met, consider acute myocardial injury from:
- Myocarditis (look for viral prodrome, pericardial involvement)
- Stress cardiomyopathy (emotional/physical trigger, apical ballooning)
- Pulmonary embolism (dyspnea, hypoxia, right heart strain)
- Acute cardiomyopathies
If troponin chronically elevated without acute changes, consider:
- Hypertrophic cardiomyopathy - look for LVH on echo, family history, dynamic LVOT obstruction
- ARVC - look for epsilon waves, T-wave inversions V1-V3, RV dilation/dysfunction, family history
- Heart failure (elevated BNP/NT-proBNP)
- Renal failure
- Chronic myocarditis
Specific Red Flags for Cardiomyopathies
For HOCM, look for:
- Unexplained LVH (especially septal thickness >15mm)
- Family history of HCM or sudden death
- Exertional dyspnea or syncope
- Systolic murmur that increases with Valsalva
- If troponin elevated: extend Holter monitoring duration to capture NSVT 3
For ARVC, look for:
- Left bundle branch pattern ventricular tachycardia
- T-wave inversions in V1-V3 with epsilon waves
- Family history of ARVC or sudden death in young relatives
- RV regional wall motion abnormalities or aneurysms on imaging
- History of endurance athletics 7
Critical Pitfalls to Avoid
Do not assume elevated troponin = MI - This is the most common error. Without ischemic evidence, it's myocardial injury, not infarction 1.
Do not ignore chronically elevated troponin - In cardiomyopathies, even stable elevations carry prognostic significance for arrhythmic risk 2, 4, 5.
Do not use point-of-care troponin assays for diagnosis - Their sensitivity is substantially below central laboratory high-sensitivity assays 9.
In HOCM with elevated troponin, do not use standard Holter duration - These patients need extended monitoring to detect NSVT 3.
Consider sex-specific troponin cutoffs - The association between troponin and ventricular arrhythmias in HCM was only present when sex-specific cutoffs were used 4.
Bottom Line for Clinical Practice
Both ARVC and HOCM cause troponin elevation through chronic myocardial injury from progressive myocyte loss and replacement with fibrofatty tissue (ARVC) or from hypertrophy-related injury and fibrosis (HOCM). The troponin elevation in these conditions is not from acute coronary occlusion but from the disease process itself 1, 2. In HOCM specifically, elevated troponin independently predicts ventricular arrhythmias and should prompt more aggressive arrhythmia surveillance 4, 3, 5.