An updated clinical primer on large artery mechanics: implications of pulse waveform analysis and arterial tonometry.
OBJECTIVE
The use of pulse wave analysis with arterial tonometry has accelerated over the last year. Despite approval from the US Food and Drug Administration in 2001 on the use of generalized transfer function to generate the central (aortic) pressure wave from the radial waveform, this technique is still questioned. This review summarizes major findings on (a) value of arterial tonometry in determining indices of cardiovascular function, (b) use of these indices in outcome and drug studies, (c) relevance to major trials on blood pressure reduction.


RESULTS
Pulse pressure has emerged as a better predictor of cardiac ischemic events than systolic, diastolic, and mean brachial pressure. Central systolic and pulse pressure and augmentation index have shown an even better relation with cardiovascular events and with outcomes. The claim by specific angiotensin-converting enzyme inhibitor and angiotensin receptor blocker drugs of their benefits "beyond blood pressure lowering" has been challenged on the basis of greater reduction in central and aortic pressure compared with brachial pressure measured by cuff sphygmomanometer, as shown by the pREterax in regression of Arterial Stiffness in a contrOlled double-bliNd study. Augmentation index is higher in hypertension, is inversely related to body height, and can be reduced by exercise. Augmentation index shows a linear relation with age up to 60 years. Regrettably, recent major trials such as the Comparison of Amlodipine versus Enalapril to Limit Occurrences of Thrombosis, Prevention of Events with Angiotensin Converting Enzyme Inhibition, and Valsartan Antihypertensive Long-term Use Evaluation studies have not included pulse wave analysis to distinguish the relative benefit of different drugs.


CONCLUSIONS
Pulse wave analysis will assist in a better understanding of hypertension as well as in establishing the extent of cardiovascular disease and for monitoring therapy.
O'Rourke
Michael F
MF
St. Vincent's Clinic, University of New South Wales, 438 Victoria Street, Darlinghurst, Sydney, NSW 2010, Australia. m.orourke@unsw.edu.au
Adji
Audrey
A
D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D001158:Arteries / Q000187:drug effects / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology*; D002318:Cardiovascular Diseases / Q000188:drug therapy / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000503:physiopathology; D008365:Manometry / Q000379:methods; D008991:Monitoring, Physiologic / Q000379:methods; D011673:Pulsatile Flow / Q000187:drug effects / Q000502:physiology; D011674:Pulse; D015203:Reproducibility of Results
D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors