Basis for use of central blood pressure measurement in office clinical practice

Recent studies have shown value of arterial tonometry to generate central aortic pressure so as to explain drug effects, and predict outcome. This article describes experience with such modern pressure pulse waveform analysis in a clinical practice dealing predominantly with patients suffering from ischemic heart disease, hypertension, and cardiac failure. We describe the use of radial artery tonometry on consecutive 9,710 occasions (1,505 patients) attending a cardiovascular outpatient clinic. Ascending aortic pressure was calculated with two methods, either using a generalized transfer function with SphygmoCor^® (AtCor Medical, Sydney, NSW, Australia) or from direct analysis of the radial waveform. With the SphygmoCor^® method, aortic systolic pressure was 13 (SD 6) mm Hg less than brachial. Results were similar with the second method (average difference 14 SD; 5 mm Hg), but this method was inapplicable in 9% of cases. Differences with age in aortic systolic and pulse pressure were similar to those described in a normal cohort. Differences between aortic and peripheral pressure values were predictable on the basis of waveform patterns at either site. The radial tonometry method helped characterize aging change, identified spurious systolic hypertension of youth, and greater hemodynamic benefit of "new" over "old" antihypertensive drugs. Analysis of the pressure waveform has the potential to improve office management of patients with hypertension, cardiac failure, and angina.