Prevalence of Hypertrophic Cardiomyopathy in the UK Biobank Population

This cohort study examines the prevalence of hypertrophic cardiomyopathy in the UK Biobank population.

Methods | This study was covered by the general ethical approval for UK Biobank.The participants signed an electronic consent form at the time of their visit to the UK Biobank assessment center.
We adapted an automatic segmentation algorithm based on deep learning 5 to measure LV wall thickness (maximum longitudinal distance between the epicardial and endocardial contours).We applied this method to calculate MLVWTs from short-axis measurements of 44 836 participants.Images with outlying MLVWT values and MLVWTs of 13 mm or more were manually validated by 2 European Association of Cardiovascular Imaging CMR level 3 experts (L.R.L. and N.A.).We excluded individuals with hypertension and aortic stenosis based on self-reported medical history and hospital episode statistics and those with phenocopies (Fabry disease, amyloidosis, glycogen storage diseases, and RASopathies).

Apical lateral
The value above each bar corresponds to the proportion of individuals with maximal wall thickness greater than the threshold value.
Guidelines 1 consider that MLVWT values of 15 mm or more in White individuals and 20 mm or more in Black individuals are in favor of HCM vs hypertensive heart disease.If we included these participants regardless of hypertension status, prevalence of HCM was 0.22% (95% CI, 0.18%-0.27%).The presence of MLVWT values of 15 mm or more was mostly located in the basal anterior and anteroseptal segments (Figure).
Discussion | To our knowledge, this is the largest HCM prevalence study based on imaging.Our estimates of 0.11% to 0.22% are consistent with previous reports; the sex-based difference was present in previous studies to a similar degree 2,3 and might be partially explained by wall thickness not being ad-justed to sex or body size.It is not entirely clear what the causative mechanism of left ventricular hypertrophy for the cases within 13 to 14 mm is.Environmental factors might be a relevant contributor.The higher volumes might be partially explained by the same reason, associated with larger body sizes; left ventricular dimensions and derived volumes are known to be smaller in echocardiography compared with CMR, because the contrast between the blood pool and endocardial border is worse.Older ages may reflect the age-associated penetrance of HCM.There is an increased prevalence of women and healthy volunteer selection bias in the UK Biobank, which might limit generalizability of our findings to more diverse populations.However, the use of a more accurate imaging technique, the very large cohort (>40 000), the inclusion of individuals with MLVWT values of 13 mm or more, and a more nuanced approach regarding the presence of hypertension, likely compensated for these limitations.

Statin Prescribing and Dosing-Failure Has Become an Option
To the Editor We read with great interest the robust study by Adusumalli et al, 1 which compared the effect of passive with active prompts in an electronic health record to improve optimal statin dosing.Even among patients with atherosclerotic cardiovascular disease (ASCVD), there was negligible impact.Inertia for prescribing and titrating statins adversely affects the quality of care.This is remarkable, given that statins reduce risk for myocardial infarction, ischemic stroke, revascularization, and death and that higher doses of statins reduce risk more than lower doses. 2The role of low-density lipoprotein cholesterol in atherogenesis is one of the most established cause-and-effect relationships in all of medicine.The optimal dose and potency of statin therapy based on risk is highly defined by guidelines around the world.Cardiovascular mortality is rising in the US, and health care disparities persist for women and racial/ethnic minority groups.Lack of long-term adherence to statin therapy is correlated with heightened risk for cardiovascular events and mortality. 3omen and members of racial/ethnic minority groups consistently demonstrate lower levels of long-term adherence to statin therapy.Hundreds of analyses have confirmed worldwide that statin adherence and persistence are poor.Often statins are down-titrated even when there is no reason to.Among patients with ASCVD, statin adherence at 5 years postinitiation is approximately 21%. 4 Among Medicare beneficiaries, more than half are not prescribed a statin after an ASCVD event.Why are we so lax about such a critical intervention for patients with ASCVD?Why do so many patients obviate risk reduction by prematurely stopping their statin?
Statin intolerance and resistance account for part of the explanation.Negative media reports increase statin resistance (refusing to take statins because of adverse effects, also known as the nocebo effect) and statin discontinuation.Statin intolerance is unlikely to be as prevalent as many reports suggest, especially in light of a new study showing that adverse effects are approximately equal among patients taking a statin or placebo. 5In most patients, the benefits of statins far outweigh their risks.This should be emphasized at both the patient and population levels.We should also dispel bad information about statins.Patients presenting with adverse effects should undergo workup and a structured treatment interruption, and then statin switching should be considered; there should be restraint against simply giving up without appropriate counseling and helping patients understand there can be a trial-and-error period during which several statins may be required.The current status quo must change.
Laszlo Mark, MD, PhD Istvan Reiber, MD, PhD Peter P. Toth, MD, PhD Figure.Prevalence of Left Ventricular Hypertrophy and Distribution of Maximal Wall ThicknessPrevalence of abnormal wall thickness A Luis R. Lopes, PhD Nay Aung, PhD Stefan van Duijvenboden, PhD Patricia B. Munroe, PhD Perry M. Elliott, MD Steffen E. Petersen, DPhil

Table .
Characteristics of Participants in the UK Biobank Letters jamacardiology.com(Reprinted) JAMA Cardiology July 2021 Volume 6, Number 7