Is hypertensive heart disease the same as Hypertrophic Cardiomyopathy (HCM)?

From the Guidelines

No, hypertensive heart disease is not the same as hypertrophic cardiomyopathy (HCM). These are two distinct cardiac conditions with different causes, characteristics, and treatments. Hypertensive heart disease develops as a consequence of chronic high blood pressure, where the heart muscle thickens (left ventricular hypertrophy) in response to the increased workload of pumping against elevated blood pressure, as noted in the 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy 1. This is an acquired condition that develops over time with poorly controlled hypertension. In contrast, HCM is primarily a genetic disorder characterized by abnormal thickening of the heart muscle, particularly the ventricular septum, that occurs independently of external factors like high blood pressure. HCM is typically inherited as an autosomal dominant trait caused by mutations in genes coding for cardiac sarcomere proteins.

Some key differences between the two conditions include:

• The presence of left ventricular outflow tract obstruction (LVOTO) in most patients with HCM, which is not typically seen in hypertensive heart disease 1
• The pattern of ventricular remodeling, with HCM often showing asymmetric septal hypertrophy, whereas hypertensive heart disease tends to show more concentric hypertrophy 1
• The presence of family history and genetic mutations in HCM, which are not typically seen in hypertensive heart disease 1
• The clinical features that assist in the differential diagnosis, such as regression of LVH with tight blood pressure control, and the presence of right ventricular hypertrophy, late gadolinium enhancement on cardiac magnetic resonance imaging, and severe diastolic dysfunction in HCM 1

While both conditions involve heart muscle thickening, their underlying mechanisms, clinical presentations, complications, and management approaches differ significantly. Hypertensive heart disease is treated by controlling blood pressure with medications like ACE inhibitors, ARBs, beta-blockers, and lifestyle modifications, as recommended by the 2020 AHA/ACC guideline 1. In contrast, HCM management focuses on symptom relief, preventing complications, and may include beta-blockers, calcium channel blockers, surgical myectomy, or alcohol septal ablation in selected cases, as discussed in the 2014 ESC guidelines on diagnosis and management of hypertrophic cardiomyopathy 1.

It is essential to accurately diagnose and differentiate between these two conditions to provide appropriate treatment and management, as noted in the 2018 JACC review topic of the week on exercise training for patients with hypertrophic cardiomyopathy 1. By understanding the distinct characteristics and treatment approaches for each condition, healthcare providers can improve patient outcomes and reduce morbidity and mortality.

From the Research

Hypertensive Heart Disease vs HCM

• Hypertensive heart disease and hypertrophic cardiomyopathy (HCM) are two distinct cardiac conditions that can present with similar symptoms and characteristics, making differential diagnosis challenging 2.
• HCM is a genetic disorder characterized by thickening of the heart muscle, which can lead to obstruction of blood flow and increased risk of sudden death 3.
• Hypertensive heart disease, on the other hand, is a condition caused by high blood pressure, which can lead to thickening of the heart muscle and increased risk of heart failure 4.

Key Differences

• The presence of hypertension does not necessarily distinguish between HCM and hypertensive heart disease, as many patients with HCM also have hypertension 4.
• The QRS duration, a measure of the time it takes for the heart's ventricles to depolarize, is significantly shorter in HCM than in hypertensive heart disease, and can be used as a diagnostic marker to distinguish between the two conditions 5.
• An integrated algorithm that incorporates MRI parameters such as left ventricular ejection fraction, end systolic and end diastolic volumes, mean maximum left ventricular wall thickness, and global longitudinal and circumferential strain can also be used to differentiate between HCM and hypertensive heart disease 6.

Diagnostic Challenges

• The diagnosis of HCM with moderate hypertrophy is challenging, and hypertensive heart disease is the most common differential diagnosis that mimics the left ventricular hypertrophy of HCM 5.
• A novel diagnostic tool, the D-HCM score, has been developed to identify primary HCM, and includes factors such as absence of antihypertensive drugs, family history of unexplained sudden death, QRS duration, and maximum wall thickness 5.
• An integrated algorithm that incorporates MRI parameters and clinical features can also be used to differentiate between HCM and hypertensive heart disease, and has been shown to have high sensitivity and specificity in both LGE-positive and LGE-negative subjects 6.