Should pulse pressure become part of the framingham risk score?

An increased pulse pressure suggests aortic stiffening. New evidence also suggests that pulse pressure is a more sensitive measure of risk than other indexes of blood pressure in middle-aged and older persons. We relatated pulse pressure to the risk of cardiovascular events in the general population and to assessed whether pulse pressure could improve the Framingham risk prediction. In a population based cohort study, 378 men and 391 women over the age of 50 (mean 62.7 years) were followed. Sex-specific Framingham cardiovascular risk scores were derived from age, systolic pressure, diastolic pressure, total and HDL cholesterol, smoking status and the presence or absence of diabetes mellitus. The cut-off points used to develop a pulse pressure score were calculated by determining the percentile points corresponding to the blood pressure categories in the Framingham risk score. We calculated relative hazard rates by multiple Cox regression. After a median follow-up of 7.2 years (range: 11 months -15 years) a total of 148 cardiovascular events occurred. In Cox regression analysis a 10 mmHg higher pulse pressure was associated with 31% (P<0.0001) increase in the risk for cardiovascular events (fatal and non-fatal) after adjustment for sex, age, total and HDL cholesterol, smoking and the presence of diabetes mellitus. After adjustment for the same risk factors, a one point increment in the blood pressure score and pulse pressure score was associated with a 40% and 48% (both P<0.0001) increase in the risk of fatal and non-fatal cardiovascular events, respectively. When both the blood pressure and pulse pressure scores were forced into a Cox model, only the pulse pressure score remained statistically significant (P<0.0001) with a relative hazard rate of 1.37 (CI:1.16-1.69). These prospective data suggest that pulse pressure may improve the Framingham risk prediction among middle-aged and older individuals. Further studies, especially in the Framingham cohort are warranted.