Risk assessment in hypertrophic cardiomyopathy: contemporary guidelines hampered by insufficient evidence

The estimated prevalence of hypertrophic cardiomyopathy is 1 in 500 but many individuals have a subclinical phenotype. Many patients with this condition have an excellent prognosis similar to that of the background population and these individuals are characterised by the absence of major risk factors for sudden death. 4 Several risk factors for sudden death have been identified. 15 The generally accepted major risk factors include: family history of sudden death; unexplained syncope; non-sustained ventricular tachycardia (NSVT) on ambulatory monitoring; severe hypertrophy (≥30 mm); and abnormal blood pressure response to exercise (although this risk may be relevant only in those under the age of 40 years). 67 Additional ‘risk modi