When I made the post I was thinking of atherosclerosis, the primary cause of heart disease. It is in fact true to say that people can have heart disease without high cholesterol (by any definition of high). Here’s a more precise question and answer by o3-mini
Can you have heart disease without hardened or soft plaques?
Heart disease is an umbrella term that encompasses a wide range of conditions affecting the heart. While atherosclerosis—characterized by the buildup of hardened (calcified) or soft (unstable) plaques in the coronary arteries—is a common cause of coronary artery disease (CAD), it is not the only pathway to heart disease. There are several conditions in which heart disease occurs without the presence of these traditional plaques.
Alternative Mechanisms of Heart Disease
- Coronary Microvascular Dysfunction (CMD):
In CMD, the small coronary arterioles fail to dilate properly, leading to inadequate blood flow to the myocardium despite the absence of significant plaque in the larger coronary arteries. Patients can experience angina and ischemic symptoms, but standard imaging tests for larger vessel disease might appear normal.
- Coronary Vasospasm:
Transient constriction of the coronary arteries can reduce blood flow. This condition, sometimes referred to as variant or Prinzmetal’s angina, is due to a spasm of the arterial wall rather than a fixed plaque. The temporary nature of the spasm can still lead to myocardial ischemia.
- Myocardial Bridging:
This congenital anomaly occurs when a segment of a coronary artery tunnels through the heart muscle rather than lying on its surface. During systole, the tunneled segment can be compressed, which may impair blood flow without the involvement of atherosclerotic plaque.
- Inflammatory and Immune-Mediated Cardiomyopathies:
Conditions such as myocarditis, which is inflammation of the heart muscle often triggered by infections or autoimmune processes, can lead to heart disease independently of atherosclerotic plaque formation. Similarly, stress-induced cardiomyopathy (Takotsubo syndrome) involves transient dysfunction of the heart muscle due to emotional or physical stress, without the presence of coronary plaques.
- Genetic and Structural Disorders:
Hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic right ventricular cardiomyopathy are examples of conditions that primarily involve the heart muscle or electrical system. These diseases may not be associated with coronary plaques but still result in significant cardiac morbidity and mortality.
Clinical Implications
Understanding that heart disease can occur without the classic signs of atherosclerosis is crucial for accurate diagnosis and treatment. Patients presenting with chest pain or other cardiac symptoms may undergo a range of diagnostic tests—from coronary angiography and cardiac MRI to stress tests—that help to differentiate between these conditions. Management strategies will vary considerably depending on the underlying cause; for example, treatments for coronary vasospasm differ from those aimed at atherosclerotic blockages.
Conclusion
Yes, it is entirely possible to have heart disease without the presence of hardened or soft plaques. A variety of mechanisms—including microvascular dysfunction, vasospasm, inflammatory processes, and genetic cardiomyopathies—can lead to heart disease independent of traditional atherosclerosis. Recognizing these differences is key to developing appropriate treatment strategies tailored to the specific underlying pathology.
