Transcript Related Guidelines

What Are the Indications for Genetic Testing in Heart Failure Patients?

Alanna A. Morris, MD, MSc · Emory University

Disclosures

September 08, 2020

This transcript has been edited for clarity.

Genetic testing is extremely important to consider in patients with heart failure. We know that in cases of idiopathic dilated cardiomyopathy, for example, there may be a genetic component present in as many as 30% to 50% of cases. We know that other etiology, such as transthyretin amyloidosis, also has a genetic component. For instance, the V122I mutation is thought to be present in as many as 3% to 5% of African Americans.[1] 

I think a family history is a key component of the evaluation when a clinician is considering sending genetic testing. Guidelines tell us that, at minimum, we should obtain a three-generation family history. We may need to obtain medical records and/or postmortem reports to validate the family history that is reported from patients and other family members. We want to make sure that clinicians utilize genetic counselors when appropriate. This can be particularly useful in the context of variant adjudication, facilitating family member testing, and counseling of family members. 

Mutation-specific genetic testing is recommended for family members if a causative mutation is identified in dilated cardiomyopathy, for instance, in the proband. Not only can the genetic testing help guide clinical decision making, but also it can also help in terms of guiding surveillance and screening of family members. 

For example, ICD placement might be indicated in patients who are asymptomatic and found to have a pathogenic lamin mutation or a pathogenic ARVC mutation, where we know the risk of sudden cardiac death may be very high, even if the patient does not have symptoms. Again, the presence of a mutation can also help guide cascade genetic testing in at-risk family members, and help clinicians and genetic counselors identify appropriate screening intervals for at-risk family members. 

Some of the questions that still linger are who to test. This is something that's evolving. If clinicians are going to pursue genetic testing, it's recommended that the patient in the family who has the most severe manifestations of disease be tested first. When to test may be less clear. Most experts would recommend that genetic testing be sent at the time that the diagnosis is made. However, we know that public datasets that are accumulating information on various rare variants and more common variants in dilated cardiomyopathy and other types of cardiomyopathy are constantly growing. Some experts have even argued that we might want to consider repeat genetic testing at certain intervals, every 5 to 10 years, as our databases expand.

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