Abstract 54: A Comparison of Blood Pressure-Lowering Treatment Decisions Based on Levels of Blood Pressure, Age, and Risk
Introduction: The goal of primary prevention is to direct treatment to individuals who will derive greatest benefit. However, single risk factors such as blood pressure or age incompletely capture absolute risk and potential treatment benefit for the individual, thus providing a role for multivariable risk assessment. In this study, we aim to compare blood pressure treatment decisions based on levels of systolic blood pressure (SBP), age, or pretreatment risk.
Methods: We used individual participant data from participants without cardiovascular disease in the Blood Pressure Lowering Treatment Trialists’ Collaboration, a prospective overview of randomized blood pressure trials. Three treatment strategies based on thresholds of SBP, age, or five-year Framingham risk estimates were compared by calculating expected number of cardiovascular events and net benefit using graphical methods and decision curve analyses. Strategies were compared as differences in the areas under the curves expressed as percentages of the maximum possible area, with bootstrap-obtained confidence intervals.
Results: We analysed 16,419 individuals with 53,571 person-years of follow-up. At every level of number of individuals treated or number of events expected, the risk-based approach using the Framingham risk estimates appeared superior to SBP (risk minus SBP-based treatment decisions = -2.8% [95% CI -4.1% to -1.3%]) or age (risk minus age-based decisions -2.6% [95% CI -4.7% to -0.7%]) (Figure). For a treatment threshold based on expected absolute risk reduction, net benefit was maximized using Framingham risk estimates for a threshold of 1 to 4%, although the differences did not meet statistical significance.
Conclusions: Blood pressure treatment decisions based on estimated absolute risk appear more efficient than age- or SBP-based treatment decisions, across a wide range of treatment thresholds. These results support prioritizing risk-based blood pressure treatment strategies in the primary prevention of cardiovascular events.
Author Disclosures: K.N. Karmali: None. D.M. Lloyd-Jones: None. J. van der Leeuw: None. D. Goff: None. K. Rahimi: None. J. Sundstrom: None.
- © 2014 by American Heart Association, Inc.