Cumulative BP measurements improve CVD risk prediction models

Swapping singular blood pressure measurements for long-term, cumulative ones could improve CVD risk prediction models, Northwestern University researchers report in the current online edition of JAMA Cardiology.

“Long-term cumulative systolic blood pressure (SBP) is significantly associated with increased rates of atherosclerotic cardiovascular disease (ASCVD) development, independent of single SBP levels,” corresponding author Lindsay R. Pool, PhD, MPH, and colleagues wrote in the journal. “However, published ASCVD risk prediction algorithms only include currently measured SBP.”

That includes the 2013 American College of Cardiology/American Heart Association guidelines, Pool et al. said, which use a single SBP value to assess quantitative risk of ASCVD.

Pool, of the Department of Preventive Medicine at Northwestern’s Feinberg School of Medicine in Chicago, and her team challenged that standard by substituting five- and 10-year cumulative SBP data into the ACC/AHA risk equations, comparing those results with ones generated using singular SBP measurements. 

The study enrolled nearly 12,000 participants, 16 percent of whom had an ASCVD event during the 10 years of follow-up. The authors found the addition of long-term cumulative BP data resulted in significant improvements in two measures of success: the net reclassification index at event rate and relative integrated discrimination index.

“Despite relatively high correlation between current SBP and long-term cumulative SBP, substituting either five- or ten-year cumulative SBP in the ASCVD risk prediction equations significantly improved their ability to correctly classify individuals in terms of their risk for ASCVD, although improvements were small in magnitude,” Pool et al. wrote. “These improvements are comparatively modest when considering coronary artery calcium score—another novel cardiovascular risk predictor—but blood pressure is frequently measured and widely available in longitudinal electronic health record data.” 

The researchers said other work has established cumulative SBP as an indicator for ASCVD risk, but future studies are needed to find the most appropriate value of cumulative SBP, as well as a host of other contributing factors.

“Implementation of use of cumulative SBP for risk prediction could feasibly occur without change to standard clinical practice, although it might be preferentially implemented in large health systems with robust electronic data capabilities,” Pool and her team wrote.