About obstructive HCM (oHCM)

Obstructive hypertrophic cardiomyopathy (oHCM) is a chronic, progressive and potentially debilitating disease that can prevent patients from living with normality.^1-4 HCM can be broadly categorised into two forms, obstructive HCM (oHCM) and non-obstructive HCM (nHCM).³

oHCM and nHCM are commonly caused by sarcomere mutations, resulting in excess myosin-actin cross bridging and hypercontractility of the heart muscle.^1,5,6

HCM is characterised by LV hypertrophy (≥15 mm) that cannot be explained by another cardiac or systemic disease, with the presence of a peak LVOT gradient of ≥30 mm Hg indicative of obstruction (oHCM).^3,7-9

The estimated global prevalence of HCM is 1 in every 500 people, although many cases remain undiagnosed.³

In the UK, approximately 4 in every 10,000 people are diagnosed with HCM each year, with oHCM accounting for around 68% of these cases.¹⁰

The majority of HCM cases are obstructive^3,9

oHCM occurs when the blockage caused by the thickened heart muscle substantially reduces blood flow out of the left ventricle, which is referred to as LVOT obstruction.^3,9

LVOT obstruction (defined as a peak instantaneous LVOT pressure gradient ⩾30 mmHg) occurs in ~25-30% of patients under resting conditions, but in up to 70% of patients either under resting conditions or with provocation with physiologic manoeuvres (such as Valsalva or exercise).¹¹

≤ 70%

of patients with HCM have LVOT obstruction, either with provocation or at rest.¹¹

Challenges in diagnosis

Variable disease presentation and non-specific symptoms can make diagnosing oHCM difficult.^3,12 Diagnosis generally includes multiple lines of evidence, such as the patient's medical and family history, physical examination findings, and a series of diagnostic tests such as ECG, echocardiography (ECHO), and cardiac magnetic resonance (CMR).^9,13,14

Symptom burden

Patients with oHCM may experience a wide range of debilitating symptoms, including breathlessness, fatigue, chest pain, heart palpitations, syncope, and dizziness.³

Due to this wide range of symptoms, patients with symptomatic oHCM suffer from reduced quality of life compared with the general population.^4,15

Find out more about the symptoms of oHCM here.

Current treatment landscape

Current pharmacological therapies (such as beta blockers and calcium channel blockers) used for treating oHCM offer a variable degree of symptomatic relief but do not address the underlying cause of the disease.^5,16

Septal reduction therapies are complex invasive procedures that may carry important risks to patients and may result in irreversible poor outcomes.^5,16

There remains an unmet need for a licensed, non-invasive treatment option that not only alleviates symptoms but also targets the root pathophysiology of oHCM.^5,16-18

Targeted therapies that aim to reduce actin-myosin cross-bridge formation have the potential to directly modulate the hypercontractility that drives LVOT obstruction, offering a more disease-specific approach to managing oHCM.^5,16-18

Explore the current treatment landscape in obstructive HCM

Treatment landscape

Abbreviations

CMR, cardiac magnetic resonance; ECG, electrocardiogram; ECHO, echocardiography; HCM, hypertrophic cardiomyopathy; LV, left ventricular; LVOT, left ventricular outflow tract; oHCM, obstructive hypertrophic cardiomyopathy.

References

Ho CY et al. Circulation. 2018;138(14):1387–1398.
Olivotto I et al. Circ Heart Fail. 2012;5(4):535–546.
Zaiser E et al. J Patient Rep Outcomes. 2020;4(1):102.
Capota R et al. Health Qual Life Outcomes. 2020;18(1):351.
Olivotto I et al. Lancet. 2020;396(10253):759–769.
Marian AJ, Braunwald E. Circ Res. 2017;121(7):749–770.
Arbelo E et al. Eur Heart J. 2023;44(37):3503–3626.
Pantazis A et al. Echo Res Pract. 2015;2(1):R45–R53.
Ommen SR et al. Circulation. 2020;142(25):e558–e631.
Schultze M et al. Eur Heart J. 2022;43(Supplement_2):ehac544.1747.
Mathai S, Williams L. Ther Adv Chronic Dis. 2022;13:20406223221136074.
Argulian E et al. Am J Med. 2016;129(2):148–52.
Basit H et al. Hypertrophic cardiomyopathy. StatPearls Publishing. 2024. Available from: https://www.ncbi.nlm.nih.gov/books/NBK430788/. [Accessed July 2025].
National Organization for Rare Disorders. Obstructive Hypertrophic Cardiomyopathy. Available from: https://rarediseases.org/rare-diseases/obstructive-hypertrophic-cardiomyopathy/. [Accessed July 2025].
Magnusson et al. BMC Cardiov Disord 2017;17(1):121.
Desai N et al. Clin Ther. 2022;44(1):52–66.e2.
Tuohy CV et al. Eur J Heart Fail. 2020;22(2):228–40.
Stătescu C et al. Int J Mol Sci. 2021;22(13):7218.

3500-GB-2500137 | October 2025

oHCM and nHCM are commonly caused by sarcomere mutations, resulting in excess myosin-actin cross bridging and hypercontractility of the heart muscle.1,5,6

HCM is characterised by LV hypertrophy (≥15 mm) that cannot be explained by another cardiac or systemic disease, with the presence of a peak LVOT gradient of ≥30 mm Hg indicative of obstruction (oHCM).3,7-9

The estimated global prevalence of HCM is 1 in every 500 people, although many cases remain undiagnosed.3

In the UK, approximately 4 in every 10,000 people are diagnosed with HCM each year, with oHCM accounting for around 68% of these cases.10

The majority of HCM cases are obstructive3,9