Genetic arrhythmia programs are paving new roads for personalized cardiac care—from preventing unnecessary cautionary testing or treatment to improving screening.
Melvin Scheinman, MD—the first person to perform catheter ablation for arrhythmia in a human patient, now chief of the Comprehensive Genetic Arrhythmia Program at the University of California, San Francisco—believes genetic testing will lead to the "ultimate form of personalized medicine," writes Gregory A. Freeman of HealthLeaders Magazine.
"If you examine the genetic background of a patient, you may be able to identify sensitivity to specific drugs, propensity for developing some very serious heart disorders, and at the same time rule out those same things for other people," said Scheinman to HealthLeaders.
"That is really what personalized medicine is all about—delivering the right care to the patient because you truly understand the patient and don't have to treat him or her as just a member of a group with certain statistical risks."
A proliferation of genetic arrhythmia programs "across the country" have been introducing new, measured responses to a sudden cardiac death in the family—preventive healthcare for some, but not all family members.
"We are studying patients with arrhythmia syndromes to check them and their family members for genetic abnormalities and, depending on the diagnosis, we can determine a genetic mutation up to 80 percent of the time," said Scheinman to HealthLeaders. "We can pinpoint those at risk of dying from serious heart rhythm disorders."
To arryhthmia and beyond
Genetic testing has the potential to transform cardiac care from a field of risk factors, groups, and uncertain diagnoses into a field of "pinpoint" accuracy and truly individualized care, at least in those conditions where genetics are identified and influential.
The buck doesn't stop with arrhythmia, says Scheinman. "The main thrust now is to find the genes responsible for coronary artery disease, atrial fibrillation, and other cardiovascular conditions," he said to HealthLeaders. "This is the next big thing."
The next big thing may require some patience, however. "The genetic origins of cardiac arrhythmia were relatively straightforward when compared to what we're seeing with these other conditions," said Scheinman to HealthLeaders. For genetic testing of other conditions, "practical application has been slower."
And even for arrhythmia, some kinks still need to be worked out.
Genetic tests misdiagnosing black Americans?
Not all genetic tests are created equal—in many senses of the word.
A recent press release from Harvard Medical School suggests that genetic testing may be disproportionately misdiagnosing black Americans with hypertrophic cardiomyopathy due to "racially biased methodologies in early studies."
False positive diagnoses of hypertrophic cardiomyopathy in black Americans "stemmed from inadequately designed clinical studies that used predominantly white populations as control groups," reads the press release.
Where precision matters, racial and ethical inclusiveness in research is all-important, says Zak Kohane, MD, PhD, senior investigator on the study. "This is the essence of precision medicine," he said.
For cardiac care to become a truly individualized and precise practice through genetic testing, reanalysis of "decades-old genetic studies" may be necessary—and possible, say the researchers, through the newly created Exome Aggregation Consortium—a compilation of large-scale sequencing projects.
In the meantime, physicians should remember to "interpret genetic test results by cross-referencing them against racially matched controls," say the researchers.
Researchers expect more genetic variants to be reclassified in the next decade, according to the press release, which means interpreting test results in the context of "rapidly evolving knowledge" could pose a "serious challenge for clinicians."
Costs of genetic testing are falling
Still, Scheinman and others are optimistic that genetic testing will soon be an integral part of cardiovascular care—perhaps with genetic counselors joining the interdisciplinary cardiac care team on a more widespread basis.
At the heart of that transformation? Costs, of course—if testing costs continue to fall, improving screening and efficiency through genetic testing would become a no-brainer.
However, in terms of costs and applications, genetic testing is a "constantly moving target" for hospitals says Thomas P. Thomas P. Cappola, MD, ScM of the Perelmen School of Medicine at the University of Pennsylvania. Due to the considerable expertise required, "it's not the kind of thing that is easily deployed," he said to HealthLeaders.
Julianne Wojciak, MS, a licensed genetic counselor working closely with Dr. Cappola, sees disruptive technology trends pushing costs lower in the near future. "I believe we are right on the cusp of genetic testing for cardiac conditions being very mainstream and low cost," she said to HealthLeaders.
Some genetic tests are priced out-of-pocket under $500—a good thing, since reimbursement is still uncertain.