For more than a century, the hypertension management was based on non-invasive measurement of brachial blood pressure (BP), but not central aortic pressure (CAP) measurement. The reason for not measuring the CAP widely is mainly due to the fact that, to-date, there is no device accurate, affordable, non-invasively and simple enough to be used in a home or clinic setting. The present technique is either an invasive angiographic measurement, or using a very expensive and cumbersome system which is only used in research labs.
Figure: CASP- the pressure at the root of the Aorta (largest artery of the body) as it emerges from the heart
Central Aortic Systolic Pressure (CASP), it has been shown in many studies to be the strongest independent risk factors for stroke, heart attacks and the likelihood of survival after such an event.
CASP – Central Aortic Systolic Pressure.
This is the blood pressure at the root of the aorta or the largest artery in the body, as the blood is being pumped out of the heart. This pressure is called Central Aortic Systolic Pressure or CASP. CASP has been shown to be an important factor in the relation to strokes and cardiovascular events, more so than the brachial pressure, or the pressure at the arm commonly.
CASP is different and usually lower than the brachial pressure in normal people. When we are young, below 40 years old, the difference between CASP and the brachial pressure can be significant (up to 30 mmHg). However, as we age, the aorta gets stiffer and the compliance reduces. As a result, the CASP increases and comes much closer to the brachial pressure. In patients with high blood pressure, the CASP can be abnormally high for his age, showing “pre-mature” stiffening of the aorta.
It has also been shown that certain class of drugs used in the treatment of high blood pressure can also have an adverse effect on the CASP, increasing it instead of reducing, as shown in the CAFÉ study. Therefore it is important to show that the treatment a patient is taking actually result in lowering the CASP and not the reverse. By reducing the CASP of the patient, we are reducing the risks of stroke and heart events.