The objective of this study was to test if combining antecedent BP recordings with current risk factors including hypertension mediated organ damage (HMOD) improves risk stratification for subsequent cardiovascular disease.
Design and method:
Antecedent systolic BP (SBP) was defined as the average of measurements obtained at the first visit (1982–1984) and at the second visit in 1988. Current SBP was the measurement obtained at the third visit (1993–1994). Four measures of HMOD were examined at the third visit. Participants were defined as having HMOD if they had one of the following: presense of atherosclerotic plaque(s), increased pulse wave velocity, increased urine albumin creatinine ratio or left ventricular hypertrophy. We excluded individuals with CVD, diabetes or individuals receiving antihypertensive or lipid lowering treatment.
The endpoint for evaluation consisted of major adverse cardiovascular events (MACE) including myocardial infarction, cerebrovascular disease and arrhytmia. Cox proportional-hazards regression models were used to evaluate associations between antecedent SBP and incident CVD.
Subjects were divided into two age categories; a middle-aged group (aged 41 or 51 years) and an older group (aged 61 or 71 years). From 1993 to 2010 394 events were observed.
Current and antecedent SBPs were associated with MACE, independently of traditional risk factors in both age groups. When current and antecedent SBP were evaluated together, current SBP was not significantly associated with MACE in the middle-aged subgroup [HR = 1.09 (1.04–1.48), P = 0.18] but remained associated with MACE in the older subgroup [HR = 1.21 (1.10–1.34), P < 0.01]. Contrariwise, antecedent SBP was only associated with MACE in the middle-aged subgroup [HR = 1.24 (1.04–1.48), P = 0.02] with the association attenuated in the older subgroup [HR = 1.04 (0.92–1.18), P = 0.52].
Adding antecedent SBP to traditional risk factors did not improve the predictive power of the Cox regression model; Delta-C-index = 0.0015, P = 0.11.
In healthy non-medicated middle-aged subjects antecedent BP is associated with cardiovascular outcome independently of current BP, traditional risk factors and HMOD. However improvement in risk stratification might be limited.