Systolic blood pressure levels among adults with hypertension and incident cardiovascular events: The atherosclerosis risk in communities study

摘要

IMPORTANCE Studies document a progressive increase in heart disease risk as systolic blood pressure (SBP) rises above 115mmHg, but it is unknown whether an SBP lower than 120mm Hg among adults with hypertension (HTN) lowers heart failure, stroke, andmyocardial infarction risk. OBJECTIVE To examine the risk of incident cardiovascular (CV) events among adults with HTN according to 3 SBP levels: 140mmHg or higher; 120 to 139mmHg; and a reference level of lower than 120mmHg. DESIGN, SETTING, AND PARTICIPANTS A total of 4480 participants with HTN but without prevalent CV disease at baseline (years 1987-1989) from the Atherosclerosis Risk in Communities Study were included. Measurements of SBP were taken at baseline and at 3 triennial visits; SBP was treated as a time-dependent variable and categorized as elevated (≥140mmHg), standard (120-139mmHg), and low (<120mmHg). Multivariable Cox regression models included baseline age, sex, diabetes status, BMI, high cholesterol level, smoking status, and alcohol intake. MAIN OUTCOMES AND MEASURES Incident composite CV events (heart failure, ischemic stroke,myocardial infarction, or death related to coronary heart disease). RESULTS After a median follow-up of 21.8 years, a total of 1622 incident CV events had occurred. Participants with elevated SBP developed incident CV events at a significantly higher rate than those in the low BP group (adjusted hazard ratio [HR], 1.46; 95%CI, 1.26-1.69). However, there was no difference in incident CV event-free survival among those in the standard vs low SBP group (adjusted HR, 1.00; 95%CI, 0.85-1.17). Further adjustment for BP medication use or diastolic BP did not significantly affect the results. CONCLUSIONS AND RELEVANCE Among patients with HTN, having an elevated SBP carries the highest risk for cardiovascular events, but in this categorical analysis, once SBP was below 140mmHg, an SBP lower than 120mmHg did not appear to lessen the risk of incident CV events.