Abstract 14013: The Effect of Mid-life Blood Pressure Change and Anti-Hypertensive Treatment on Subsequent Left Ventricular Mass - A Life Course Approach

Abstract

Background- Clinical practice focuses on current blood pressure (BP) levels with treatment (HTT) initiation once a threshold is crossed. There is less work relating the effects of previous changes in BP and HTT over time on future cardiac structure.

Methods- 1653 study-members from the longest running birth cohort study in the UK (MRC-1946 study) underwent echocardiography and BP measurement aged 60-64y. BP had previously been measured at 36, 43 and 53y. First, separate regression models investigated the association between systolic BP (SBP) at each of the 4 ages at which it was measured and left ventricular mass index (LVMI) at 60-64y, adjusted for sex, age at clinic visit and clinic attended. For each prior SBP measure, additional models assessed whether earlier SBP remained predictive once current SBP was included. Final adjustments were made for HTT at the time SBP was measured, body mass index and presence of type 2 diabetes at 60-64y. Regression models with LVMI and rates of change in SBP for the periods 36-43y, 43-53y and 53-60/64y conditional on earlier SBP were constructed.

Results- SBP from 36y positively predicted LVMI at 60-64y and SBP from 53y predicted LVMI independent of SBP at 60-64y (fully adjusted model); β coefficient at 53y = 0.20 g/m²; 95% CI: 0.12,0.28; p = <0.001. From 43y, HTT was associated with a greater LVMI (even if BP had normalized), compared to an individual who had never been on HTT(β coefficient at 43y = 11.69g/m²; 95% CI: 2.76, 20.61; p = 0.010). Faster rates of increase in SBP from 43-53y and 53-60/64y were both associated with increased LVMI at 60-64y. Rate of increase between 43-53y was associated with the largest change in future LVMI (β coefficient for 43-53y = 3.16 g/m²; 95% CI: 1.59,4.73; p = <0.001).

Conclusions- SBP over mid-life positively predicts future LVMI. Being on HTT from 43y onward is associated with a larger LVMI at 60-64y even if SBP has "normalized" on HTT. Rate of change in SBP in mid-life is a more important predictor of future LVMI than current SBP. Current strategies for monitoring and treating high BP may need to change with focus shifting to early identification and HTT of those with rapid rises in SBP (irrespective of baseline SBP level).