For patients with hypertension, using estimated pulse wave velocity to evaluate aortic stiffness might be used to estimate risk for a future cardiac event or as a marker for a therapeutic treatment target, according to a study published in JAMA Network Open.
The researchers this exploratory, hypothesis-generating, post hoc secondary analysis study aimed to assess the relationship between the estimated pulse wave velocity and cardiac events or death from cardiovascular causes to evaluate if estimated pulse wave velocity is a better predictor for the risk for a cardiac event when compared with current methods of risk prediction of the Framingham Risk Score, and to examine whether improving estimated pulse wave velocity through antihypertensive treatment led to a reduction in cardiovascular event risk. Data for this study came from the Systolic Blood Pressure Intervention Trial (SPRINT; ClinicalTrials.gov identifier: NCT01206062). SPRINT was a randomized, open-label, controlled, 2-group trial that evaluated patients who were at high risk for cardiovascular disease and the effect of standard treatment (a target systolic blood pressure of 140 mm Hg) or intense treatment (a target systolic blood pressure of 120 mm Hg) on nonfatal cardiac events and death from cardiovascular causes in these individuals. For this post hoc analysis, the estimated pulse wave velocity was calculated using the equation from the Reference Values for Arterial Stiffness Collaboration and used age and mean blood pressure as variables. The primary outcome was the effect treatment had on the estimated pulse wave velocity and whether this change affected survival.
Of the 9361 patients included in this analysis, 6029 were men, 3332 were women, and the mean age was 67.9 years old. Analysis of baseline data indicated that estimated pulse wave velocity was associated with all-cause death (hazard ratio [HR], 1.65; 95% CI, 1.46-1.86; P <.001), stroke (HR, 1.45; 95% CI, 1.20-1.76; P <.001), heart failure (HR, 1.70; 95% CI, 1.42-2.04; P <.001), cardiovascular death (HR, 1.39; 95% CI, 1.10-1.76; P =.006), the primary outcome (HR, 1.30; 95% CI, 1.17-1.43; P <.001), and noncardiovascular death (HR, 1.76; 95% CI, 1.53-2.03; P <.001).
After 12 months of antihypertensive treatment, estimated pulse wave velocity was associated with all-cause death (HR 1.50; 95% CI, 1.31-1.72; P <.001). The addition of estimated pulse wave velocity to the risk prediction model for all-cause death improved the C index from 0.67 (95% CI, 0.64-0.69) to 0.69 (95% CI, 0.66-0.72; P =.03), which had a better risk discrimination score than the Framingham Risk Score.
Over the course of the 12-month study, the cohort in the intensive treatment protocol showed a mean reduction in estimated pulse wave velocity while the standard treatment showed no change (-0.75 m/s vs 0.03 m/s, respectively; P <.001). When assessing the effect of estimated pulse wave velocity on cardiac events and all-cause death, patients in the intensive treatment cohort who also showed an improvement in estimated pulse wave velocity had the best prognosis after treatment. Patients in the intensive treatment cohort who did not show an improvement in estimated pulse wave velocity had similar outcome risk as those in the standard treatment cohort. Baseline estimated pulse wave velocity was an independent predictor of death, regardless of treatment group, with the intensive treatment cohort having an HR of 1.78 (P <.001) and the standard treatment cohort having an HR of 1.55 (P <.001).
Limitations include the post hoc nature of the study, a limited follow-up time frame to assess mortality, limited power to assess individual outcomes, and using the Framingham Risk Score as the risk predictor model, which might have a small overestimation of risks.
The researchers concluded that their “. . .data supports an incremental predictive role of [estimated pulse wave velocity] as well as possible use of this marker as a therapeutic target in patients with hypertension.”
Vlachopoulos C, Terentes-Printzois D, Laurent S, et al. Association of estimated pulse wave velocity with survival: a secondary analysis of SPRINT. JAMA Netw Open. 2019;2(10):e1912831.