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".