Our understanding of the genetic basis of adult-onset cardiomyopathy is rapidly evolving. Most of us learned to practice medicine in a paradigm that relied on detailed disease phenotyping, but now we have the ability to incorporate genetic and genomic information into routine clinical care. Even if you cannot remember the last time you thought about genes or pedigrees, here are a few modifications you can make to your practice today that will help you keep up with this exploding field of cardiovascular medicine.
1) Take a minimum three-generation family history in all patients with a primary cardiomyopathy.
- The goals of taking a family history are to learn (1) whether the cardiomyopathy is familial, (2) about disease characteristics among family members, (3) if it is inherited in a specific pattern, and (4) to identify at-risk relatives.
- Most adult-onset cardiomyopathies are inherited in an autosomal dominant pattern, but other inheritance patterns (e.g. dignetic, multigenic) are possible and need further study.
- Importantly, an individual can have a genetic form of cardiovascular disease without having affected relatives. Most often, this is due to recessive inheritance, de novo mutations/variants, or reduced penetrance.
2) Use focused questions to obtain the family history.
- The use of vague terms like “heart attack” can lead clinicians away from pursuing an inherited etiology of disease and prevent them detecting other important cardiovascular diagnoses like sudden cardiac death in family members.
- Ask specific questions regarding heart failure symptoms (e.g. presence or absence of dyspnea at rest or on exertion, paroxysmal nocturnal dyspnea), arrhythmia symptoms (e.g. palpitations, presyncope, syncope with or without exertion), and sudden death (e.g. drowning, single-vehicle accidents) in family members.
- Knowing about relatives’ cardiovascular procedures like arrhythmia ablation, cardiac surgery, device implantations, or heart transplantation can also be helpful.
- If a multisystem syndrome like a laminopathy or Fabry disease is suspected, familiarize yourself with the extracardiac manifestations and include pertinent questions in your history.
3) Remember that diagnosing an individual with an inherited cardiovascular disease is just the first step in the process.
- In cardiovascular genetics, a key concept is the transition of practice from individual patient-based care to family-based care. By incorporating the information you generate from your comprehensive multi-generational family history, you also gain insight into disease penetrance, expression, age of onset, and pleiotropy.
- Generally, cardiomyopathies are considered “medically actionable” because evidence-based treatments to reduce morbidity and mortality exist.
- Beyond just having effects on medical and device therapies, following this paradigm of family-based care also has implications for reproductive and family planning and lifestyle practices.
If you are interested in learning more about this topic, check out the 2018 update to the Heart Failure Society of America Practice Guideline on the Genetic Evaluation of Cardiomyopathy (PMID: 29567486).