19/05/2005
A journal belonging to the "Nature" group publishes research on cardiology by the University of NavarraDr. Javier Díez´s research team confirm that hypertension causes pathological scars in the heart (myocardial fibrosis)
A journal belonging to the
Nature
group has just published an article on cardiology by a team of
specialists at the Center for Applied Medical Research (CIMA), which is
attached to the University of Navarra and the University Hospital. The
article reports research directed by Dr. Javier Díez which supports the
hypothesis, which is increasingly being accepted, that fibrosis (scar
formation) is the lesion which determines the future development of the
heart in cases of hypertension. This study appeared in the April issue
of
Nature Clinical Practice Cardiovascular Medicine.
It is known that when blood pressure rises and hypertension occurs, the
heart is overloaded: it pumps blood against greater resistance as a
result of the extra pressure. For most of the twentieth century, as Dr.
Díez explained, doctors thought that the growth of the cardiac muscle
(left ventricular hypertrophy, or LVH) present in patients with
hypertension was beneficial for the heart. This alteration was believed
to enable the heart to pump blood more strongly, to compensate for the
greater resistance caused by hypertension.
However, "clinical
and epidemiological studies at the end of the twentieth century
revealed that patients with hypertension and LVH had more frequent and
severe cardiac complications than those without LVH. This led some
groups of clinical and basic researchers to form the hypothesis that
not all was well with the hypertrophy of the cardiac muscle in response
to hypertension. They also thought that this hypertrophy might mask
some decisive changes which could, in the long term, indicate a worse
prognosis for patients with hypertension and LVH than for those without
the latter".
The research team at the University of
Navarra, and other groups of scientists, thought that the hypertense
heart might undergo structural changes which could cause massive scar
formation (myocardial fibrosis).
20 years of research culminate in a diagnostic method and treatment
Twenty years ago, Dr. Díez and his co-workers felt intuitively that the
gradual replacement of heart muscle cells by inert fibers played a
critical role in the deterioration of the heart and the appearance of
clinical complications in patients with hypertension. During these
years, "our team has contributed evidence from animals and patients
with hypertension which shows that this hypothesis is true, and we have
explored some of the mechanisms by which it is produced".
Perhaps the most important point is that the researchers at CIMA and in
the University Hospital have developed a non-invasive method for
diagnosing myocardial fibrosis, and shown that certain pharmacological
treatments not only prevent fibrosis, but also repair the damage.
The article published in
Nature Clinical Practice Cardiovascular Medicine,
edited by Valentín Fuster, was written by Javier Díez, Arantxa González
and Begoña López of the University of Navarra, and Ramón Querejeta of
the Hospital Donostia in San Sebastián. They put together an overview
of their own team's contributions, and those of other groups working in
the same area.
The fact that this hypothesis has been
confirmed holds tremendous potential importance for health care: 30% of
the adult population has hypertension, and half of them have signs of
LVH and are therefore exposed to the dangers of myocardial fibrosis.
These data mean that of the 8 million people with hypertension in Spain
today, 4 million have LVH and fibrosis. As the article shows, doctors
already have diagnostic tools and pharmacological measures to protect
these 4 million Spanish people from myocardial fibrosis. According to
Dr. Díez, this medical research offers society "a message of hope".