Systolic Versus Diastolic Blood Pressure and Risk of Coronary Heart Disease???The Framingham Study

Abstract A comparison of the contribution of systolic versus diastolic blood pressure to risk of coronary heart disease and the role of mean arterial pulse pressure and systolic lability have been examined prospectively in 5,127 men and women during 14 years of biennial follow-up studies. Similar gradients of risk of subsequent coronary heart disease were observed whether persons were classified by their systolic or diastolic pressure, and no “safe” or critical level could be identified. Assessment of the net effect of each, employing discriminant analysis, indicated a stronger association of systolic than diastolic pressure with risk of coronary heart disease. Neither the systolic and diastolic pressure measurements in combination nor the pulse pressure and the mean arterial pressure measurements alone discriminated better than the systolic measurement alone. Systolic lability did not predict incidence of coronary heart disease independently of the associated level of blood pressure. There was a trend of declining relative importance of diastolic and a corresponding increase in the importance of systolic pressure with advancing age. Only in those under 45 was diastolic pressure predominant. The level of casually obtained blood pressure was a good predictor of coronary heart disease. The current practice of assessing the importance of blood pressure at all ages largely on the basis of diastolic pressure and the commonly held view concerning the innocuous nature of an elevated level of systolic pressure in the elderly requires reevaluation.