A recent Japanese study found that HCM patients who demonstrated late gadolinium enhancement (LGE) on MRI (which is indicative of myocardial scarring) were more likely to carry a genetic mutation associated with HCM than others who did not show LGE.
According to researchers at the University of Michigan, family members of HCM patients who have tested negative for genes associated with HCM and without a family history of HCM will usually be found to be free of HCM during routine family screening. And, in accordance a recent Australian study, relatives of these patients may be able to benefit from less rigorous screening protocols.
Patients with a known sarcomere mutation appear to have a different clinical profile, according to the researchers: they have more hypertrophy; they are younger when diagnosed; they have a higher risk for adverse events; and they are more likely to have a family history for the condition.
In contrast, when the initial diagnosis is made in a patient who is 50 or older with no known genetic mutations, a negative family history, and sigmoidal septal pattern hypertrophy, reduced family screenings may be appropriate and less burdensome. In addition, hypertension, large family size with no other affected family members, less severe hypertrophy, and lack of life-threatening complications related to HCM may provide additional comfort to families of newly diagnosed HCM patients.
The reduced protocol would consist of a single screening of adult family members, with the caveat that if and when any additional family additional member is found to have HCM, a more traditional screening protocol be instituted.
(Note that standard screening guidelines recommend screening of all first-degree family members of patients beginning with adolescence, repeated annually through the end of adolescent growth, and repeated every 3 – 5 years for life.)
A recent study published in the American Heart Association’s Circulation found that a majority of individuals who have a Sudden Arrhythmia Death Syndrome (SADS) diagnosis and/or relatives applying for various types of insurance (such as health, life, travel, and disability) were denied coverage. The preexisting SADS diagnosis was the predominant reason given for denial.
Though HCM does not generally fall under the SADS umbrella, these findings are equally concerning for HCM families.
SADS conditions generally include:
- Brugada Syndrome
- Catecholaminergic Polymorphic Ventricular Tachycardia (CPVT)
- Long QT Syndrome (LQTS)
- Short QT Syndrome (SQTS)
- Timothy Syndrome
- Wolff Parkinson White (WPW)
For more information on these conditions, visit the SADS Foundation.
A study published today by Dr. Carolyn Ho, of Boston’s Brigham and Women’s Hospital, and colleagues, including Australia’s Christopher Semsarian, found that there are several factors which appear to stand out in young people who later go on to develop HCM.
The children/adolescents/young adults who participated in the study all carried at least one gene associated with HCM, and were members of families with strong histories of HCM. None of the 38 young people had clinical manifestations of HCM at the beginning of the study period, while 4 went on to develop HCM by the end of the study. In collecting the data analyzed in the study, the test results of the 4 individuals with HCM were compared to the 34 individuals that did not have HCM at the end of the study.
The factors associated with the development of overt HCM, as identified by the researchers, were: abnormal left ventricular relaxation and higher ejection fraction, EKG changes, longer mitral valve leaflets, higher NT-proBNP concentrations and troponin values.
In the conclusion, the authors acknowledged the need for further research and investigation in order to better understand the natural course and evolution of the disease.