Abstract 17986: Multiple Single Day Blood Pressure Measurements and Their Impact on Coronary Heart Disease, Stroke, and Heart Failure Risk Prediction: The Atherosclerosis Risk In Communities (ARIC) Study
BACKGROUND: Although systolic blood pressure (SBP) varies through the day, single SBP measures are used in all coronary heart disease (CHD), heart failure (HF) and stroke risk prediction equations. Changes in SBP clearly affect estimated risk. However, the magnitude of change in risk when different SBP measures performed within one day are used in risk equations is not known.
METHODS: Same day multiple SBP measurements (sitting, standing and supine) were performed by certified technicians using a Dinamap device in 11,075 ARIC study participants (mean age 53.9 ± 5.7 years, 57% with history of smoking, 10% diabetic and 31% hypertensive). We estimated 10 year CHD, HF and stroke risks for each SBP measure and classified individuals as 0-5%, 5-10%, 10-20% and >20% risk.Then, we evaluated changes in individual risks within a day.
Results: (Table): Substituting mean sitting SBP for standing and supine SBP in the Framingham CHD Risk Score (FRS) reclassified 8.3% and 10.2% of the subjects, and in the ARIC Coronary Risk Score (ACRS), 7.1% and 9.6%, respectively. Similarly, when stroke and HF risks were evaluated using ARIC risk scores 11.7% and 12.3% were reclassified when standing SBP was used, and 10.7% and 11.7% were reclassified with supine SBP measures. The maximum changes in an individual’s estimated 10 year risk were 21%, 26% and 24% for CHD, stroke and HF risk, suggesting greater than one risk category (e.g.,low to high risk) change in a day. When different sitting SBP measures (taken within minutes of each other) were used, 6.7%, 6.5%, 6.5% and 8.0% of subjects were reclassified when FRS, ACRS, ARIC stroke and HF risks were estimated.
CONCLUSION: SBP changes within a day can result in statistically significant changes in estimated CHD, stroke, and HF risk. Our study has implications for the use of a single SBP measure to determine an individual’s cardiovascular risk, and raises questions on the utility of current risk prediction algorithms in patient management.
- © 2013 by American Heart Association, Inc.