Rheumatic heart disease: Not gone, but almost forgotten

Barcelona, Spain - The congress center in Barcelona that played host to the 2006 World Congress of Cardiology contains a labyrinth of rooms named after capital cities. In the space of two days, three symposia in Lima and Cape Town, rooms that could easily have seated 500, were attended by barely 40 people each time (and they appeared to be the same 40 people). Yet the subject under discussion was not some obscure syndrome or basic science study but a type of heart disease that affects up to 20 million people worldwide.

Dr Jonathan Carapetis

Most doctors practicing in the developed world have never encountered a case of rheumatic heart disease, but the condition is still a major problem in developing nations, striking children and young adults in their prime, causing up to 500 000 deaths annually, and disabling hundreds of thousands of people. However, next to the "big three"—HIV, TB, and malaria—rheumatic heart disease ranks low on many scales.

And yet "this is the most solvable cardiac problem affecting the developing world today," says Dr Jonathan Carapetis (Menzies School of Health Research, Darwin, Australia). Carapetis, a pediatric infectious disease expert, is a man with a mission—he is the chair of the World Heart Federation (WHF) Scientific Council on Rheumatic Heart Fever and Rheumatic Heart Disease.

He applauds the World Heart Federation for stepping in where the World Health Organization has stumbled. "It is clear that for WHO, rheumatic heart disease is no longer a focal point, although they still do some good things, such as producing an excellent management guideline," he says. He hopes that the WHF initiative will help galvanize developing countries to conduct research and work together to tackle rheumatic fever and heart disease.

The WHF is wasting no time. During the Barcelona meeting, it launched a web-based resource for clinicians, health practitioners, and policy makers, and last month, to coincide with World Heart Day, it announced a major new commitment to the prevention of rheumatic fever/rheumatic heart disease in Africa.

Kenyan Heart Wall. A list of the symptoms of "strep throat" that is displayed in schools and other public places.

 

There is much work to be done. Reliable prevalence data on rheumatic fever and rheumatic heart disease are required in many regions of the world to aid in planning prevention and treatment campaigns. Countries also need to run registries of patients with rheumatic fever and heart disease, develop national prevention programs, and train healthcare workers. There is also debate among doctors on whether to concentrate on primary or secondary prophylaxis, and research is needed in these fields to enable cash-strapped governments to tackle the disease in the most cost-effective way. And the key to accurately diagnosing rheumatic heart disease is to widen the availability of echocardiographs and to standardize a screening approach.

Carapetis and a dedicated band of doctors from the developing world are determined to tackle these problems on the front line—by intervening and promoting research in the affected countries. "We need a list of critical questions that need to be asked in a research agenda," he says.

Rheumatic heart disease is the most important sequelae of acute rheumatic fever, which is caused by group A streptococci (GAS) and usually presents in childhood, affecting five- to 14-year-olds—although it can strike people up to the age of 30. It usually begins as pharyngitis, or "strep throat," and then progresses to include joint pain. In some populations, however, sore throat is rare, and the disease begins with GAS skin infection. Rheumatic fever is thought to result from a delayed immune response to the bacteria, although the exact pathogenic mechanisms remain unknown, and diagnosis is difficult.

In 20% to 30% of cases, there is no cardiac involvement, but people often contract rheumatic fever more than once, and the damage is cumulative. Rheumatic heart disease accounts for up to 60% of all cardiovascular disease in young adults and children, robbing countries of their most useful citizens and undermining national productivity.

Although the disease was rife in Western countries until 50 years ago, improvements in sanitation and housing and the advent of widespread use of antibiotics mean it is now extremely rare. Although better epidemiological data are needed in many areas, there are a number of recognized hot spots where prevalence is exceedingly high—including sub-Saharan Africa, South Central Asia, and the Pacific, including indigenous populations living in Papua New Guinea, Australia, and New Zealand. There are also emerging nations, such as Brazil, where prevalence is low in affluent areas but remains high among native communities and in poorer regions.

Worldwide prevalence of rheumatic heart disease

The holy grail would be a GAS vaccine, but, while promising candidates are in phase 1 and 2 trials, it is likely to be many years before such a product becomes available.

Cardiac problems are sometimes seen in children and adolescents but generally manifest at age 25 onward and increase with age and with each recurrence of rheumatic fever. They include valvulitis/endocarditis, myocarditis, and pericarditis. When patients develop severe mitral or aortic regurgitation, this is often the "point of no return," whereby only cardiac surgery will suffice.

"In most countries, surgical treatment of rheumatic heart disease chews up the vast majority of funds allocated to controlling this disease," Carapetis explains. But instead, the aim should be to try to catch people before cardiac damage occurs or at least before it becomes too severe, he notes, although he acknowledges that surgery—where it is available—will continue to be needed for many years to come.

In an ideal world, all schoolchildren would get swabbed for strep throat and receive primary prophylaxis with antibiotics to prevent them from developing rheumatic fever in the first place. But many doctors believe that this is just not feasible, practical, or cost-effective in many areas of the world.

Dr Nigel Wilson

In fact, a recent large school-based trial in 24 000 children in New Zealand showed no statistical difference in the incidence of rheumatic fever between those who tested positive for streptococcus and received oral penicillin for 10 days and those who tested positive but received no treatment.

"This was a brutally disappointing result," said Dr Nigel Wilson (Green Lane Hospital, Auckland, New Zealand), a pediatric cardiologist who was involved with the trial.

"This is the most important piece of rheumatic fever research in recent years," says Carapetis. "Although treatment of strep pharyngitis is important for individuals, I believe it is dangerous to advocate primary prevention when it has not been proven cost-effective. I'm not going to go to any developing country and say that this is where you should put your money." He also argues that this policy would be pointless among populations that have a very high prevalence of rheumatic fever but where strep throat is rare, such as the Aboriginal communities in Australia that he treats.

But critics say it has already been proven that injecting penicillin is more effective than giving it orally and that this should be the method adopted for primary prevention. A group in South Africa, led by Dr Bongani M Mayosi (Groote Schuur Hospital and University of Cape Town, South Africa), has estimated that only 60 children per year need to be treated to prevent one episode of rheumatic fever, at a cost of $46 per episode prevented. "If we wait for secondary prevention, we wait for children with heart failure," Mayosi says.

Dr Bongani M Mayosi

Wilson conceded to heart wire : "I personally think we would have gotten better results if we had used a jab, but we didn't as it was seen as somewhat politically incorrect for children."

While the debate will no doubt rumble on, many of those on the ground are concentrating on developing effective secondary-prevention programs to stop the recurrence of rheumatic fever and thereby help to prevent more severe cardiac damage.

Secondary prophylaxis involves years of treatment with either an injection of penicillin (once a month or twice weekly) or oral penicillin taken twice daily (or sulfonamides or erythromycin in the case of a penicillin allergy). The intramuscular approach is widely recognized as being the most effective.

In patients without carditis, five years of secondary prophylaxis or until the age of 18 is thought sufficient, For those with mild or healed carditis, 10 years of therapy or until the age of 25 should be enough. And most agree that all patients with rheumatic heart disease over the age of 30 who have had no recurrence of rheumatic fever in the previous 10 years can discontinue secondary prophylaxis.

The key to making decisions on secondary prophylaxis is the availability of good screening, "and a proper cardiological evaluation," says Wilson. To date, many cases of rheumatic heart disease have been diagnosed with a stethoscope, "but these pick up the worst cases only," he says, adding, "There is no other heart disease where you wouldn't use an echo."

Advantages of echo include the fact that it allows the valve structure to be detected, which should prevent patients with carditis from being misclassified as noncarditic and vice versa (ie, to prevent people from being told they have rheumatic carditis when they don't).

However, some believe there are downsides—the high sensitivity of Doppler echo for recognizing valvular regurgitation, for example, could lead to overdiagnosis, with carditis being identified in almost every rheumatic fever patient. And the sheer cost and logistics involved with purchasing, distributing, and training field personnel in developing countries will mean that the technology will remain out of financial reach for many.

But Wilson disagrees. He was busy at the Barcelona conference, touring the booths of companies that manufacture portable echocardiographs, which, he says, are ideal to take out into the field. "These things cost in the region of $30 000 to $60 000 for one machine, which is the equivalent of about one to one and a half cardiac surgeries, so they have to be incredibly cost-effective."

In 2005, Carapetis and colleagues published a paper in Lancet Infectious Diseases noting that two million children in the world are affected by rheumatic heart disease ^[1].

"One million of these were in sub-Saharan Africa, and this really galvanized people to try to do something about this," said Mayosi.

"We realized that this topic had fallen off the radar of governments and ministries of health, and we wanted to put it back on the agenda, so we came up with an action plan entitled ASAP."

ASAP stands for awareness, surveillance, advocacy, and prevention. There is a lack of awareness of the problem among the public—who need to learn to associate sore throats with rheumatic heart disease. They are told, for example, that 2000 tons of coffee are needed to buy a heart valve, but penicillin costs only half a dollar. Also, healthcare workers need to be educated, Mayosi said, with many not even realizing that rheumatic heart disease is notifiable.

Dr Porfirio Nordet

In surveillance terms, the aim is to set up prospective registries of rheumatic heart disease in four demonstration sites—Egypt, Ethiopia, Ghana, and South Africa—and to promote the use of echo rather than a stethoscope.

"We will also advocate to put rheumatic fever/rheumatic heart disease back on the agenda of ministries of health and international agencies as a neglected disease of the poor. After all, we are talking about the most acquired heart disease of children in the world," he stated.

Dr Nawal Ahmed Kordofani

And for prevention, "We need to determine whether it is cost-effective to administer penicillin to all cases of suspected strep throat," he said. He maintains that this approach has been successful in countries such as Cuba and Costa Rica.

Dr Porfirio Nordet, former advisor to the WHO on rheumatic heart disease, told of a success story in one region of Cuba, where the prevalence was reduced from 2.27 per 1000 schoolchildren in 1986 to 0.24 per 1000 children 10 years later. "We focused on three key areas—the education of doctors, awareness of families, and compliance with secondary prophylaxis," he said. Compliance with secondary prophylaxis was improved from 50% of patients to 93.8% over the 10 years of the study. "If you put emphasis on these points, you will reduce the prevalence," he noted.

Dr Syed Faiz-Ul-Hassan Rizvi

A similar tale was relayed by Dr Nawal Ahmed Kordofani (National Heart Center, Khartoum, Sudan), who described a 10-year project in schools in Khartoum that involved educating teachers and introducing the disease into the curriculum, resulting in a 10-fold reduction in the prevalence of rheumatic heart disease between 1986 and 1996. This reduction has been maintained in Khartoum but could not be replicated elsewhere in Sudan, because other provinces lack the school-based healthcare programs that exist in the capital, she explained to heart wire .

But in rural Pakistan, there is "a pandemic of rheumatic heart disease," says cardiologist Dr Syed Faiz-Ul-Hassan Rizvi (Sheikh Zayed Medical College and Hospital, Rahim Yar Khan, Pakistan). He reported data in Heart in 2004 showing that there is a high prevalence of rheumatic heart disease among the rural population of the country and that this prevalence has not declined over the past three decades ^[2].

"Nearly all people with rheumatic heart disease, including those who know their diagnosis, do not receive the benefit of potentially lifesaving secondary prevention measures," Rizvi and colleagues noted.

Heartwire from Medscape © 2006 

Cite this: Rheumatic heart disease: Not gone, but almost forgotten - Medscape - Oct 13, 2006.