Author + information
- Received January 14, 2011
- Revision received March 28, 2011
- Accepted April 21, 2011
- Published online September 6, 2011.
- Ramón C. Hermida, PhD⁎ (, )
- Diana E. Ayala, MD, MPH, PhD,
- Artemio Mojón, PhD and
- José R. Fernández, PhD
- ↵⁎Reprint requests and correspondence:
Dr. Ramón C. Hermida, Bioengineering and Chronobiology Laboratories, E.I. Telecomunicación, Campus Universitario, Vigo (Pontevedra) 36310, Spain
Objectives We investigated whether reduced cardiovascular risk is more related to the progressive decrease of asleep or awake blood pressure.
Background Independent studies have concluded that elevated sleep-time blood pressure is a better predictor of cardiovascular risk than awake or 24-h blood pressure means. However, the impact on cardiovascular risk of changes in these ambulatory blood pressure characteristics has not been properly investigated.
Methods We prospectively studied 3,344 subjects (1,718 men and 1,626 women), 52.6 ± 14.5 years of age, during a median follow-up of 5.6 years. Those with hypertension at baseline were randomized to ingest all their prescribed hypertension medications upon awakening or ≥1 of them at bedtime. Blood pressure was measured for 48 h at baseline and again annually or more frequently (quarterly) if treatment adjustment was required.
Results With data collected at baseline, when asleep blood pressure was adjusted by awake mean, only the former was a significant predictor of outcome in a Cox proportional hazards model also adjusted for sex, age, and diabetes. Analyses of changes in ambulatory blood pressure during follow-up revealed a 17% reduction in cardiovascular risk for each 5-mm Hg decrease in asleep systolic blood pressure mean (p < 0.001), independently of changes in any other ambulatory blood pressure parameter.
Conclusions The sleep-time blood pressure mean is the most significant prognostic marker of cardiovascular morbidity and mortality. Most importantly, the progressive decrease in asleep blood pressure, a novel therapeutic target that requires proper patient evaluation by ambulatory monitoring, was the most significant predictor of event-free survival. (Prognostic Value of Ambulatory Blood Pressure Monitoring in the Prediction of Cardiovascular Events and Effects of Chronotherapy in Relation to Risk [the MAPEC Study]; NCT00295542)
- ambulatory blood pressure monitoring
- cardiovascular risk
- sleep-time relative blood pressure decline
This independent investigator-promoted research was supported by unrestricted grants from Ministerio de Ciencia e Innovación (SAF2006-6254-FEDER; SAF2009-7028-FEDER); Consellería de Presidencia, Relacións Institucionais e Administración Pública, Secretaría Xeral de Investigación e Desenvolvemento, Xunta de Galicia (PGIDIT03-PXIB-32201PR); Consellería de Economía e Industria, Dirección Xeral de Investigación e Desenvolvemento, Xunta de Galicia (INCITE07-PXI-322003ES; INCITE08-E1R-322063ES; INCITE09-E2R-322099ES; 09CSA018322PR); and Vicerrectorado de Investigación, University of Vigo. All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received January 14, 2011.
- Revision received March 28, 2011.
- Accepted April 21, 2011.
- American College of Cardiology Foundation