Genetic counselor offers insights on testing for inherited heart conditions

Illustration by waldryano
Illustration by waldryano

Genetic tests are now available for many conditions — everything from Alzheimer’s to familial hypercholesterolemia. But genetic testing isn’t necessarily the best option for everyone, and some of the tests aren’t highly accurate yet.

However, clinicians agree that genetic testing is important for people with hereditary heart conditions in their families. That’s why Stanford created the Stanford Center for Inherited Cardiovascular Disease, which specializes in caring for patients and their families with genetic disorders of the heart and blood vessels. Genetic counseling is a key part of the center, so I spoke with Colleen Caleshu, MSc, their lead genetic counselor to learn more.

What inspired you to become a genetic counselor?

“When I was in college, I was very interested in the science and molecular basis of disease. I was considering a PhD in genetics, but I was also drawn to peer counseling and psychology courses. When I looked at genetic counseling programs, they required an unusual combination of science and humanities such as psychology, ethics, genetics and biochemistry. Before going to graduate school, I spent a year with a research team that focuses on the psychological impact of familial breast cancer risk — that experience solidified that genetic counseling was what I wanted to do. For me, it comes down to a combination of loving the science and being intellectually challenged by a field that is moving really quickly, while also really being able to help people.”

What cardiovascular diseases does genetic testing identify?

“Genetic testing isn’t yet useful for all diseases or for all people. For cardiology, we recommend genetic testing when a patient is diagnosed with an inherited disease. The two most common inherited cardiac diseases are familial hypercholesterolemia and hypertrophic cardiomyopathy. We also care for patients with several other inherited heart muscle, arrhythmia and aorta diseases. If you put all of these genetic cardiac diseases together, greater than one in a 100 people have one in their genes.”

What is a typical genetic counseling appointment like?

“The clinic appointment is about an hour long. It involves establishing a relationship with the patient and their family to understand: Who are they? What are they experiencing? What are their values? What do they most need help with right now? Then we often shift to the medical side of things with a comprehensive four-generation family history. This involves a lot of detective work with the patient and afterwards — calling family members and searching medical records, death certificates and autopsy reports. The rest of the visit is a mixture of medical and genetics education, as well as psychological counseling. All medical conditions can have a psychological impact, but the genetic nature of these diseases mean they can strike healthy people at an unusually early age compared to most heart diseases. And they have reproductive and family planning implications.

Our genetic counselors also function within a broader, multidisciplinary team, including a cardiologist who gives his assessment, diagnosis and management recommendations. And all of this is based on a separate, hour-long intake appointment with a nurse that happens prior to the clinic appointment. “

How can genetic counseling help?

“Genetic counseling definitely benefits both the patient and the patient’s family — by helping them cope better with the familial heart condition and by helping healthy family members get the necessary medical workup and tests.

For example, a patient came to us a few years ago after being diagnosed with hypertrophic cardiomyopathy. Several generations of his family had the disease, and two of his siblings died suddenly from it a few years apart. He was really wrestling with whether or not to get an implanted defibrillator. He came to our center to get everything we offer.

We had several visits with him and his family members. At one point we had more than 10 family members in the room — the patient, siblings, nieces and nephews — grappling with a lot of pain and grief. We provided grief counseling and we addressed what it meant medically and psychologically for each family member. Using genetic testing, we were able to identify a disease-causing genetic variant in the original patient and his family. By proactively checking the heart of other family members, we were also able to diagnose people who didn’t know they had the disease — including members who went on to get implanted defibrillators to protect them from sudden death. Genetic counseling can absolutely save lives.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Many adults should now take statins, task force recommends

Illustration by Rf Vectorscom
Illustration by Rf Vectorscom

The U.S. Preventative Services Task Force now recommends that many adults take a low to moderate dose of statin to reduce their risk of a heart attack or stroke, even if they don’t have a history of cardiovascular disease.

Statins are drugs that reduce the production of cholesterol by the liver — lowering bad cholesterol and triglycerides and raising good cholesterol. The task force comprehensively reviewed the literature on clinical trials and observational studies involving statin use. It concluded that the benefits of using statins outweighed the harms in some patients with increased risk of cardiovascular disease.

Douglas Owen, MD, a Stanford professor of medicine and director of the Center for Health Policy, was a member of the task force when the guidelines were developed. He summarizes the new recommendations in a recent news story:

“The task force recommends that clinicians offer statins to adults who are 40 to 75 years old and have at least one existing cardiovascular disease risk, such as diabetes, hypertension, high cholesterol or smoking. They also must have a calculated risk of 10 percent or more that they will experience a heart attack or stroke in the next decade. The task force recommends that clinicians use the American College of Cardiology/American Heart Association risk calculator to estimate cardiovascular risk because it provides gender- and race-specific estimates of heart disease and stroke.”

The task force hope these new recommendations will help clinicians better identify cardiovascular risk, so their patients can take steps to reduce their risk, such as eating a healthy diet, exercising and potentially taking a statin.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

After heart transplant, who survives? New study offers tools to tell

Photo by Ms. Phoenix
Photo by Ms. Phoenix

Despite careful patient selection, only about 75 percent of heart recipients survive three years after the transplant surgery. Identifying the patients most in need of additional care has always been tricky, but now Stanford researchers have found a better way to predict which heart transplant recipients have a higher risk of dying or needing another heart transplant, as reported in Circulation today.

One key reason transplant patients die is cardiac allograft vasculopathy, an accelerated and aggressive form of coronary artery disease.

William Fearon, MD, professor of cardiovascular medicine and senior author, explained the significance of their results in a recent email:

Identifying patients at higher risk of dying from cardiac allograft vasculopathy is helpful, because it allows the transplant physicians to be more aggressive with medical therapy and monitoring than they might otherwise be, in order to hopefully prevent adverse events.

The researchers conducted a clinical trial involving seventy-four heart transplant recipients, whose heart physiology was invasively assessed within eight weeks and one year after transplantation. They found that two particular diagnostic procedures were able to successfully identify high-risk recipients — fractional flow reserve and index of microcirculatory resistance.

Fractional flow reserve is a procedure that measures the blood pressure and flow through a specific part of the coronary artery. It is often used to determine whether blood flow is significantly obstructed by a blockage or lesion, guiding a cardiologist’s decision of whether to stent the blockage.

Fearon’s team determined that a low fractional flow reserve measured soon after the transplant independently predicted the heart transplant recipients’ risk of death or retransplantation.

Index of microcirculatory resistance measures the functionality of the tiny vessels that supply blood to the heart, such as capillaries, arterioles and venules. Fearon found that a higher than normal reading measured one year after the heart transplant was also an independent predictor of the recipients’ event-free survival.

The Stanford researchers hope that more emphasis will be placed on these two invasive assessments of cardiac physiology in heart transplant recipients, so their medical regimen can be adjusted to improve the odds of their survival.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

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