The new European guidelines will definitely underscore the general importance of lowering blood pressure. “We know that regardless of the kind of treatment you give, lowering blood pressure is protective. The magnitude of pressure reduction correlates directly with the magnitude of reduction of cardiovascular morbidity and mortality. We don't care how you do it. Get the pressure below 140/90, and you reduce risk. It should be below 130/80 if patients are at high risk. All the international guidelines agree on this.”
They will also likely support the wider use of combination therapy at the outset of treatment. The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) showed that 9 of 10 high-risk hypertensive patients required more than one antihypertensive medication to achieve pressure control.
The guidelines will reinforce the general European preference for global risk assessment. “We need to look at the overall status of the cardiovascular system, not just the blood pressure measurements. The greater the risk, the more aggressive the treatment should be,” said Dr. Mancia, professor of medicine at the University of Milan-Bicocca, Italy. He stressed that total risk assessment involves consideration of subclinical organ damage such as microalbuminuria and left ventricular hypertrophy.
If patients have LVH alone or microalbuminuria alone, they do far better than if they have both (J. Hum. Hypertens. 2004;18:453–9). Early organ system damage “is prognostic, and it won't show up unless you look for it. Regression of LVH or proteinuria by treatment is associated with improved outcomes. We surmised this, but we didn't have the data in 2003,” he said.
Dr. Mancia and Dr. Giles agreed that it is these other factors that will be critical in determining if a patient with borderline high blood pressure truly needs treatment. If an otherwise healthy 65-year-old man has a pressure reading of 125/80, he probably does not need drug therapy. However, if there are elevated lipids, impaired glucose tolerance, microalbuminuria, and other indicators of risk, the rationale for treatment is much stronger.
It is important to look at blood pressure over time. A systolic measurement of 120 may seem normotensive, but if this reflects a steady and consistent increase from 90 or 100 in previous years, it is an indicator that the cardiovascular system is beginning to malfunction.
The new ESH guidelines will probably call for wider use of ambulatory and home blood pressure monitoring. Dr. Mancia stressed that office pressure measurements are limited, and cited a recent Italian study that showed progressive increase in risk if ambulatory or home pressure measurements are also increased.
Hypertension experts across the globe are beginning to question the value of brachial artery pressure measurements. “If you measure blood pressure in the brachial artery, you cannot be confident you're getting a picture of the central aortic pressures,” said Dr. Giles. He added that measurement of central aortic pressure makes a lot more sense. Currently, the technology to do so is limited to research settings, but this is a technological impediment not a conceptual one.