Cardiovascular disease risk stratification by the Framigham score is markedly improved by ambulatory compared with office blood pressure

Abstract

Introduction and objectives: Ambulatory blood pressure (BP) better predicts cardiovascular disease (CVD) outcomes than office BP measurements (OBPM). Nonetheless, current CVD risk stratification models continue to rely on exclusively daytime OBPM along with traditional factors, eg, age, sex, smoking, dyslipidemia, and/or diabetes.

Methods: Data from 19 949 participants of the primary care-based Hygia Project assessed by 48-hour ambulatory BP monitoring (ABPM) and without prior CVD events were used to compare the diagnostic accuracy, discrimination, and performance of the original Framingham risk score (RS_OFG) and its adjusted version to the Hygia Project study population (RS_AFG) with that of a novel CVD risk stratification model constructed by replacing OBPM with ABPM-derived prognostic parameters (RS_ABPM).

Results: During the follow-up, lasting up to 12.7 years, 1854 participants experienced a primary CVD outcome of CVD death, myocardial infarction, coronary revascularization, heart failure, stroke, transient ischemic attack, angina pectoris, or peripheral artery disease. Asleep systolic BP (SBP) mean and sleep-time relative SBP decline were the only joint significant ABPM-derived predictive factors of CVD risk and were therefore used to substitute for in-clinic SBP in the RS_ABPM model. The RS_ABPM model, in comparison with the RS_OFG and RS_AFG models, showed significantly improved calibration, diagnostic accuracy, discrimination, and performance (always P<.001). The RS_AFG-derived event-probabilities of 57.3% of the participants were outside the 95% confidence limits of the event probability determined by the RS_ABPM model.

Conclusions: These collective findings reveal important limitations of CVD risk stratification when based upon OBPM, as in the Framingham score, and corroborate the clinical value of around-the-clock ABPM to properly diagnose true hypertension and reliably stratify CVD vulnerability.

Keywords: Ambulatory blood pressure monitoring; Asleep blood pressure; Cardiovascular risk stratification; Escala de riesgo de Framingham; Estratificación del riesgo cardiovascular; Framingham risk score; Monitorización ambulatoria de la presión arterial; Presión arterial durante el sueño; Profundidad de la presión arterial; Sleep−time relative blood pressure decline.