From the Guidelines
Elevated Angiotensin-Converting Enzyme (ACE) levels are not typically of high clinical significance for most patients, and their measurement is not routinely used for diagnosis or monitoring of conditions in standard medical practice. While ACE plays a crucial role in regulating blood pressure through the renin-angiotensin-aldosterone system, measuring ACE levels directly is not typically necessary, as seen in the 2017 ACC/AHA/HFSA focused update of the 2013 ACCF/AHA guideline for the management of heart failure 1. Instead, clinicians focus on managing conditions like hypertension or heart failure by targeting the effects of ACE using medications called ACE inhibitors (e.g., lisinopril, enalapril), which have been shown to reduce morbidity and mortality in patients with heart failure with reduced ejection fraction (HFrEF) 1, 2. Some key points to consider include:
- ACE inhibitors have been shown to reduce mortality and morbidity in patients with HFrEF and are recommended unless contraindicated or not tolerated in all symptomatic patients 2.
- The use of ACE inhibitors is beneficial for patients with prior or current symptoms of chronic HFrEF to reduce morbidity and mortality 1.
- ACE inhibitors should be started at low doses and titrated upward to doses shown to reduce the risk of cardiovascular events in clinical trials 1. In rare cases, ACE levels may be measured to help diagnose or monitor sarcoidosis, a inflammatory condition, but even for sarcoidosis, ACE levels are not considered a definitive diagnostic test due to low sensitivity and specificity. The lack of emphasis on ACE levels is because the enzyme's activity doesn't always correlate well with disease states or treatment effectiveness, and other markers and clinical assessments are generally more useful for guiding patient care in cardiovascular and respiratory conditions where the renin-angiotensin system is involved. Therefore, the focus should be on using ACE inhibitors to manage conditions like heart failure, rather than measuring ACE levels directly.
From the Research
Significance of Elevated Angiotensin-Converting Enzyme (ACE) Levels
Elevated ACE levels are associated with various medical conditions, including:
- Granulomatous diseases, such as sarcoidosis 3, 4, 5, 6
- Cardiovascular diseases, due to the role of ACE in blood pressure regulation and vascular remodeling 7
- Nongranulomatous disorders, such as hyperthyroidism or cholestasis 6
- Other conditions, including non-Hodgkin's lymphoma, cirrhosis, and interstitial lung disease 5
Clinical Applications of ACE Levels
ACE levels can be used as a:
- Serological marker for sarcoidosis, although with low specificity and sensitivity 5
- Tool for monitoring disease activity and evaluating the effect of therapy in sarcoidosis 4, 6
- Marker for cardiovascular disease risk, due to the association between elevated ACE expression and increased risk of cardiovascular diseases 7
Limitations and Considerations
- Elevated ACE levels are not specific to sarcoidosis and can be found in other medical conditions 5, 6
- ACE levels can be influenced by various factors, including the use of ACE inhibitors and endothelial dysfunction 6
- The clinical correlation between ACE levels and disease activity in sarcoidosis is disputable 5
- Genetic testing may be necessary to confirm familial hyperactivity of ACE, a benign condition characterized by extremely elevated ACE activity 3