Do the 2017 blood pressure cut-offs improve 10-year cardiovascular disease mortality risk prediction?

Background and aims: High blood pressure (BP) is a significant predictor for cardiovascular disease (CVD) mortality. The 2017 American College of Cardiology/American Heart Association guideline reclassified the BP categories; however, its impact on CVD mortality prediction is still unclear. Our study aimed to examine whether the application of new BP cut-offs could improve 10-year CVD mortality prediction among US adults.

Methods and results: This population-based cohort study linked data from the US National Health and Nutrition Examination Survey (1988–1994 and 1999–2004) and National Death Index (up to December 31, 2015). We constructed original and modified, using new BP cut-offs, Systematic COronary Risk Evaluation models to predict 10-year CVD mortality. We measured model discrimination and calibration using the Harrell's C statistic and calibration plots, respectively. We calculated the net reclassification index to evaluate the reclassification. In addition, we compared the sensitivity, specificity, predictive values (PVs), and likelihood ratios (LRs). Among 28,964 adults (aged ≥ 20 years), 1493 have died of CVD within ten years of follow-up. The modified models had improvements in calibration and reclassification instead of discrimination compared to the original models. The modified models have higher sensitivity and negative PV; however, they have lower specificity, positive PV, positive LR, and negative LR.

Conclusions: The modified models failed to improve the discrimination of 10-year CVD mortality. However, they could increase the calibration and reclassification and capture more participants with high CVD risk. More studies are needed on the potential use of the new BP cut-offs in the CVD primary prevention.