HHypertrophic cardiomyopathy is the most common inherited heart disease worldwide. Researchers estimate that up to 1 in 200 people have the disease, which is characterized by abnormal thickening of the heart wall. This thickening can make it difficult for the heart to pump blood.

There was a time when hypertrophic cardiomyopathy was a potentially fatal disease and almost untreatable. However, the past 20 years have seen major changes in the management of the disease, which have reduced the number of deaths by an estimated 10-fold.

“Hypertrophic cardiomyopathy is difficult to live with and the outlook is grim,” said Dr. Barry Mallon, a cardiologist and hypertrophic cardiomyopathy expert at Beth Israel Lahey Health in Burlington, Massachusetts. We have a reputation for that.” However, significant advances have been made in clinical care and clinical research, and the characteristics of hypertrophic cardiomyopathy are now very different. ”

“The reality is that very few people die from this disease and fully half of the patients are in a group that we consider to be benign and stable,” he added.

Here, Maron and other experts explain what it’s like to live with hypertrophic cardiomyopathy. Learn about the different stages and forms of the disease, how and why the disease progresses, and how treatments evolve over time. They also talk about the future outlook for people diagnosed with this condition.

unpredictable disease

Some medical conditions (for example, certain forms of cancer) are characterized by different stages. These stages help determine treatment and also reflect the patient’s prognosis.

Experts say hypertrophic cardiomyopathy is different. The game is not played according to such strict rules. “This is an incredibly diverse disease, and the more we learn about it, the more complex it becomes,” says Dr. Christopher Kramer, distinguished professor and chief of cardiovascular medicine at the University of Virginia School of Medicine. The condition can affect the physical properties of the heart in a variety of ways, making it difficult to predict how the heart will perform over time, he says. “It’s hard to say to a patient, ‘You’re going to do this, and this is probably the outcome,'” he added.

Maron agrees that “there is no average” when it comes to hypertrophic cardiomyopathy. But the disease, he says, can be categorized into four general pathways. “The first pathway is the benign and stable pathway, and thankfully this is the most common of his four pathways,” he says. These patients tend to contract the disease accidentally at some point in middle age. For example, you may undergo some type of medical imaging test and your doctor may notice abnormalities in your heart function, such as a heart murmur. This leads to follow-up tests that reveal hypertrophic cardiomyopathy. In these cases, the myopathy may not be obstructive, meaning it may not be restricting blood flow, and you may just need to be monitored to make sure it isn’t getting worse.

“The second pathway involves heart failure due to some kind of blockage,” Maron says. In these obstructive cases, cardiomyopathy restricts blood flow from the heart. These patients often have symptoms such as chest pain and shortness of breath. Symptoms can range from severe to very mild, and can be so mild that people can live with them for years without worrying about them. “Patients may say they don’t have symptoms, but once they start asking questions, they find that they often can’t keep up with friends or are short of breath during exercise,” says cardiologist Dr. Milind Desai. Hypertrophic cardiomyopathy specialist at Cleveland Clinic. “Many people are unaware of how they have adapted their lifestyle to this condition over the years.”

Fortunately, heart failure related to this blockage can often be reversed with the help of some treatment, such as medication or surgery to remove part of the thickened heart muscle. In rare, severe cases, myopathy may not respond to these treatments. Or you may respond well at first, but eventually your condition worsens. “A small number of patients develop progressive hypertrophic cardiomyopathy, in which the heart muscle becomes thick and stiff and there are no symptoms, so the only option may be a heart transplant,” Desai says. “But fortunately, that’s only true for 3% to 5% of patients.”

The third pathway involves people who have hypertrophic cardiomyopathy, which causes atrial fibrillation (a condition in which the upper and lower ventricles of the heart are out of rhythm). If left untreated, atrial fibrillation can cause a stroke, and many of these patients require anticoagulants (such as blood thinners) and sometimes require medication or surgery.

“The fourth pathway is people who are at risk for sudden cardiac death,” Maron says. Identifying these cases still requires educated guesses, but modern diagnostic tools are much better at identifying at-risk patients, he says. Treatment usually involves implanting a small cardioverter defibrillator (ICD) to correct the irregular heart rhythm. “Implantable cardioverter defibrillators have saved countless lives,” he added.

These four pathways help classify hypertrophic cardiomyopathy patients into four broad groups, but experts reiterate that the course of the disease is difficult to predict. However, it is said that with proper treatment, most people diagnosed with hypertrophic cardiomyopathy will not die from the disease. “At this point, most properly managed patients can expect to live a normal lifespan,” Desai says.

read more: What you need to know about hypertrophic cardiomyopathy in children

how and why the condition progresses

Once again, experts emphasize the unpredictability of this disease. “The progression of hypertrophic cardiomyopathy is very variable,” says Dr. Kramer. “It may or may not progress. We’re doing research to understand who is most likely to progress and why.”

People with the genetic form of this condition, that is, those who have inherited one or more gene mutations associated with hypertrophic cardiomyopathy, may have a more severe and progressive form of the disease, and often , symptoms appear early in life. However, this is not always the case. “Some patients may have a genetic mutation but not develop any obvious disease. If we don’t look for them, we’ll never know they have the disease,” Desai says. he says. But whether or not people with obstructive hypertrophic cardiomyopathy have symptoms, experts say their symptoms are likely to worsen if left untreated. As the muscles thicken, symptoms develop or become more severe, increasing the risk of developing atrial fibrillation and other life-threatening complications, he said.

Although it can be difficult to predict the course of the disease, experts say people who have symptoms and are diagnosed with the disease at a younger age tend to face more challenges than those who were older at the time of diagnosis. It is said that there is. “If you’re diagnosed at age 50 or 60, the prognosis is usually good, probably similar to age-matched controls,” says Kramer. “But if you have a family history of the disease and are diagnosed at age 25, that’s not very optimal.”

Other health problems can also advance the disease. Experts say it can worsen hypertrophic cardiomyopathy caused by obesity, high blood pressure and diabetes. “It’s important to stay healthy and continue to have the ball,” Desai says.

How treatments evolve

At the time of diagnosis, most people with hypertrophic cardiomyopathy have no symptoms or evidence of obstruction. Most require no treatment other than observation.

If the disease progresses, meaning there is a blockage or other threat to the heart, treatment may require an implantable cardioverter-defibrillator or medications to manage symptoms and reduce the risk of complications. there is. For example, modern anticoagulants have “almost eliminated” the risk of stroke in people who develop atrial fibrillation as a result of hypertrophic cardiomyopathy, Maron says. Meanwhile, a new drug called mavacamten can help reduce symptoms and, in some cases, reverse some of the myocardial thickening in people with obstructive disease. Experts say the drug has helped improve the quality of life for many patients, but it is not a panacea. “Mavacamten has made a useful contribution, but so far there is nothing in this class of drugs that has a direct impact on mortality,” Maron says.

If you respond well to the drug, you must continue taking it indefinitely and be monitored quarterly to ensure that your heart function is stable. Experts say if the heart condition worsens or symptoms persist, the next step in treatment is likely to be some kind of procedure. For younger patients or those experiencing severe blockages, doctors may recommend septal myectomy, an open-heart surgery to remove the thickened muscle. “This is a one-time surgery,” Maron says. Studies have shown that more than 90% of people who undergo this surgery experience significant improvement in symptoms and enjoy long-term survival benefits. However, this procedure can be dangerous if not performed in a top-notch medical facility. For patients for whom open-heart surgery is too risky, such as older adults, experts may recommend a procedure called alcohol septal ablation. This involves injecting a small amount of alcohol into the heart, which can cause thickened muscles to contract and improve blood flow.

For a “very small number of patients,” their symptoms continue to worsen despite treatment, although the reasons are not well understood, Maron said. In such cases, a heart transplant may ultimately be necessary, he said.

positive outlook

While some new drugs have contributed to advances in the treatment of hypertrophic cardiomyopathy, experts say improved knowledge of the disease and its clinical management have contributed most to reducing mortality rates. . “When I started 40 years ago, the mortality rate was 6% per year and treatment was inadequate at best,” Maron says. Currently, his research estimates that the annual risk of death for patients is less than 1%.

Experts hope for further progress and even early intervention that can neutralize the disease before it spreads. Desai mentions gene editing as perhaps the “next frontier” in treating hypertrophic cardiomyopathy. “This involves removing the abnormal genetic material that causes hypertrophic cardiomyopathy,” he says. Gene therapy aimed at replenishing specific protein deficiencies is also an active area of ​​research. “If this concept works, in the future patients could go to the clinic, get an IV, take immunosuppressive drugs for a few weeks, and be cured or significantly improved,” he says. In the short term, experts are also studying how newer drugs, taken early, can reduce or stop the progression of symptoms. “There are a lot of exciting things happening in this space,” Desai says.

Hypertrophic cardiomyopathy remains a fickle and unpredictable enemy. But experts say they’ve learned to roll with the punches. “Things are going in the direction we wanted them to go,” Maron says. “This is now a very treatable disease.”