Twenty-four-hour versus clinic blood pressure levels as predictors of long-term cardiovascular and renal disease outcomes among African Americans

Abstract

In Caucasian and Asian populations, evidence suggests that 24-h blood pressures (BP) are more predictive of long-term cardiovascular events than clinic BP. However, few long-term studies have evaluated the predictive value of 24-h BP phenotypes (24-h, daytime, nighttime) among African Americans (AA). The purpose of this study is to evaluate the added value of 24-h BP phenotypes compared to clinic BP in predicting the subsequent fatal and non-fatal cardiovascular/renal disease events in AA subjects. AA subjects (n = 270) were initially studied between 1994 and 2006 and standardized clinic BP measurements were obtained during screening procedures for a 3-day inpatient clinical study during which 24-h BP measurements were obtained. To assess the subsequent incidence of cardiovascular and renal disease events, follow-up information was obtained and confirmed by review of paper and electronic medical records between 2015 and 2017. During a mean follow-up of 14 ± 4 years, 50 subjects had one or more fatal or non-fatal cardiovascular/renal disease events. After adjustment for covariates, clinic systolic and diastolic BP were strongly associated with cardiovascular/renal disease events and all-cause mortality (p < 0.0001). Twenty-four-hour BP phenotypes conferred a small incremental advantage over clinic BP in predicting cardiovascular/renal events, which was limited to making a difference of one predicted event in 250-1,000 predictions depending on the 24-h BP phenotype. Nocturnal BP was no more predictive than the other 24-h BP phenotypes. In AA, 24-h BP monitoring provides limited added value as a predictor of cardiovascular/ renal disease events. Larger studies are needed in AA to confirm these findings.

Ambulatory Blood Pressure Monitoring to Diagnose and Manage Hypertension

“…With regard to the time of day that is most predictive of adverse health outcomes in relation to the ambulatory BP, studies in patients 3 , 5 – 8 and populations 10 , 11 , 22 showed that the nighttime BP by far outperformed the daytime BP, although it should be confirmed in other ethnics. 32 In a substudy of the Systolic Hypertension in Europe Trial, 5 808 patients were randomized in a double-blind manner to placebo or active BP-lowering treatment. The nighttime systolic BP (midnight to 6 am ) was the most accurate predictor of end points.…”

Team Science: American Heart Association’s Hypertension Strategically Focused Research Network Experience

“…Several published articles were supported by this SFRN with several additional abstracts containing data that we plan to publish in the future. 6–13 Investigators were able to adhere to the hypotheses proposed with no major changes due to innovative ideas in implementation of the projects. In the basic science project, changes were observed in DNA methylation and gene expression in T lymphocytes (T cells) of Dahl salt-sensitive rats fed different diets, 6,7 providing new insight into the mechanisms by which immune mechanisms amplify salt-sensitive hypertension and renal damage.…”

“…8 In addition, it was observed that in Black people, 24-hour BP monitoring provides limited added value as a predictor of cardiovascular/renal disease events. 10 SFRN enabled postdoctoral fellows to participate in multiple types of research and learn how basic and clinical studies are conducted and strengths and limitations of each (Table 1). In addition to specific successes in each of the projects, The MCW Center also made critical methodological advances in the realm of methylation sequencing and analyses.…”