Prof. Enrico Agabiti Rosei delivered a lecture on the cardiovascular remodeling and its prognostic value in hypertension during the 15th European Meeting of Hypertension. He spent some time with ESHonline during the meeting to talk about this important aspect of hypertension and its treatment.
ESHonline: Good morning, Dr. Agabiti Rosei. Thank you for coming in this morning to talk about the clinical prognostic value of cardiovascular remodeling in hypertension. Briefly, would you please explain what is cardiovascular remodeling and the pathophysiology of this phenomenon?
Prof. Agabiti Rosei: Thank you. With high blood pressure values, there is an adaptation of the heart and of the large and small arteries. And this adaptation is extremely important because it is an indicator of the high risk related to hypertension, and it may become a specific goal of antihypertensive treatment.
The adaptation of the heart to the increased load may be, as you would say, concentric or eccentric, according to the value of the relative wall thickness, which is the ratio of the thickness of the wall of the left ventricle versus the left ventricular diameter, according to the fact that this ratio is above or below a certain value.
We know that patients with concentric remodeling of the heart have an increased risk because more often they have depressed systolic function, an alteration of the diastolic function, and alteration of large and small arteries. Large arteries in hypertension are characterized by an increased intima-media thickness, often associated with, at least in large elastic arteries, atherosclerotic plaque. And, these induce an increase of the afterload that furthers the development of left ventricular hypertrophy.
Small arteries in the microcirculation are associated with remodeling, which is characterized by an increased media-to-lumen ratio. Small arteries, arterioles and capillaries are also reduced in number in hypertension. And this leads to an increased total peripheral resistance, as well as a reduction of flow reserve. This is particularly important in some vascular beds, in particular the coronary vascular bed.
ESHonline: To date, the measurement of cardiovascular remodeling has been used in the experimental setting. But it appears that it is moving now into the clinical arena. Could you please explain how this is measured in the clinical setting?
Prof. Agabiti Rosei: Well, the remodeling of the heart, of the left ventricle, can be assessed using ultrasonic techniques, using echocardiography. These give precise data on how concentric or eccentric is the adaptation of the heart, as well as some more sophisticated indexes of the systolic and diastolic function, as well as a perspective of the structure of the heart. The large vessels can be again evaluated by ultrasonic techniques and there are also simple measures to assess the stiffness, the rigidity, of the arterial tree using pulse wave velocity analysis. It is much more difficult to assess the microcirculation, the small arteries, the arterioloes, and capillaries. So far we have sophisticated techniques, but in the future we hope to have more easily usable techniques in order to have information on these very important parts of the circulation.
ESHonline: In whom should cardiovascular remodeling be measured? What are the indicators of this patient population?
Prof. Agabiti Rosei: Ideally, this cardiovascular remodeling should be assessed in every patient, because it gives very useful information on the pathophysiological mechanism of hypertension. It gives information on the risk associated to this alteration, because all these alterations are indicators of a worse prognosis in hypertension.
It is also interesting to assess this because they can be favorably influenced by an appropriate antihypertensive treatment. Some antihypertensive drugs might be more effective than others. And we know that at least for the heart that the reversal of cardiac remodeling is associated with a better prognosis. We don’t know so far whether regression of structural changes in the large and small arteries may be associated to better prognosis. But it is possible that this is the case. So, ideally, this should be measured in every patient in order to assess the risk and to follow the efficacy of treatment. Of course, there are problems of cost and problems related to the very large population that should be investigated in this context. But, ideally every patient should have this evaluation.
ESHonline: How does the clinician apply the information that is obtained from this testing in the individual patient?
Prof. Agabiti Rosei: In the individual patient, it is useful in order to stratify cardiovascular risk, in order to understand the pathophysiological mechanism behind this remodeling, and in order to evaluate the efficacy of antihypertensive treatment.