Assessing Cardiovascular Risk

Abstract

High blood pressure (BP), a major established predictor of cardiovascular disease, is the leading risk factor for mortality worldwide.1,2 Both systolic BP (SBP) and diastolic BP (DBP) have continuous, independent relations with the risk of cardiovascular disease3; however, considerable uncertainty persists about the relative importance of SBP, DBP, and their combination in predicting cardiovascular risk. Article p 243 Increased peripheral resistance, which is considered to be caused by arterial vasoconstriction, traditionally has been viewed as the key determinant of DBP.4 This has led to the long-standing conviction that the cardiovascular risks associated with hypertension derive principally from the diastolic component of BP. As a matter of fact, the early releases of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure defined hypertension on the basis of elevated DBP values only (Table). View this table: Table. Evolving Definition of Hypertension in Adults According to the Joint National CommitteeGuidelines This view has been challenged by a number of studies demonstrating that SBP outweighs DBP as a predictor of cardiovascular morbidity and mortality3,5 and is not just a natural and innocuous consequence of the stiffening of the large arteries caused by aging. It was only in 1988 that the prognostic role of isolated systolic hypertension was acknowledged in the Joint National Committee Report, and since the Fifth Report published in 1993, hypertension has been defined as an elevation of SBP and/or DBP.6 Given the stronger prognostic value of SBP compared with DBP and the prominent role of aortic stiffness as a predictor of cardiovascular outcomes, a simplified definition of hypertension has been proposed.7 According to this view, the thresholds for diagnosing and treating hypertension should be based on SBP only, and DBP values should be discarded, at least in individuals 50 years of age …