Prognostic Value of the Morning Blood Pressure Surge in 5645 Subjects From 8 Populations

Abstract

Abstract-Previous studies on the prognostic significance of the morning blood pressure surge (MS) produced inconsistent results. Using the International Database on Ambulatory Blood Pressure in Relation to Cardiovascular Outcome, we analyzed 5645 subjects (mean age: 53.0 years; 54.0% women) randomly recruited in 8 countries. The sleep-through and the preawakening MS were the differences in the morning blood pressure with the lowest nighttime blood pressure and the preawakening blood pressure, respectively. We computed multivariable-adjusted hazard ratios comparing the risk in ethnic-and sex-specific deciles of the MS relative to the average risk in the whole study population. During follow-up (median: 11.4 years), 785 deaths and 611 fatal and nonfatal cardiovascular events occurred. While accounting for covariables and the night:day ratio of systolic pressure, the hazard ratio of all-cause mortality was 1. Key Words: ambulatory blood pressure Ⅲ blood pressure measurement Ⅲ morning surge Ⅲ epidemiology Ⅲ population science S everal studies showed that the incidence of cardiovascular complications peaks in the morning. 1,2 For instance, in the Multicenter Investigation of Limitation of Infarct Size Study 1 and in the Thrombolysis in Myocardial Infarction Phase II Trial, 2 the incidence of myocardial infarction was highest between 6:00 AM and 12:00 AM. Blood pressure also follows a circadian pattern, generally characterized by a fall during sleep and a sharp rise on awakening. 3 This observation gave rise to the hypothesis that an exaggerated morning surge of blood pressure might predict cardiovascular outcome. However, previous studies of populations 4 and hypertensive patients 5-7 produced contradictory results, possibly because of the small number of events and the lack of statistical power. A further issue complicating the interpretation of previous studies is the varying definitions of the morning surge in blood pressure. 8Continuing medical education (CME) credit is available for this article. Go to http://cme.ahajournals.org to take the quiz.

Prognostic Utility of Morning Blood Pressure Surge for 20‐Year All‐Cause and Cardiovascular Mortalities: Results of a Community‐Based Study

“…In a previous meta‐analysis of subjects from 8 populations,5 STMS amplitude >90th percentile was an independent risk factor of mortality and cardiovascular events after adjusting for the same covariables as in our study. Given the relatively small sample size and fewer end points in our study (607 all‐cause deaths), the STMS amplitude only reached borderline prognostic significance, whereas all other MS parameters were of no significant prognostic value.…”

“…Although a large and rapid BP increase in the early morning has been associated with a poor prognosis, previous studies focused only on the amplitude rather than the rate of BP increase 5. BP is normally low at night while sleeping and starts to increase a few hours before waking up, exhibiting a physiological diurnal variation.…”

“…We first evaluated the hazard ratios (HRs) of these parameters in quintiles and >95th percentile for all‐cause and cardiovascular mortalities. The baseline multivariable Cox model was constructed on the basis of significant results from the univariate analyses for sex, age, height, alcohol, dyslipidemia, smoking, hypertension, total cholesterol, low‐ and high‐density lipoprotein cholesterol, triglycerides, heart rate, office SBP, 24‐hour SBP, 24‐hour DBP, daytime SBP, nighttime SBP, morning SBP, and a previous systematic review 5. We determined the threshold for high status of the morning surge parameters by identifying the 95th percentile.…”

“…Ambulatory BP monitoring (ABPM), by tracking changes in the BP level over 24 hours, provides the opportunity to test the hypothesis that the high incidence of cardiovascular complications in the morning is linked to an exaggerated night‐to‐day BP elevation 3. Indeed, the morning BP surge (MS) has been demonstrated to be an important prognostic factor of cardiovascular end points in Japanese elderly hypertensive patients4 and in many other population‐based cohorts 5, 6. In a meta‐analysis of 5645 subjects from 8 cohorts, sleep‐trough MS (STMS) significantly and independently associated with cardiovascular outcomes 5.…”

“…Indeed, the morning BP surge (MS) has been demonstrated to be an important prognostic factor of cardiovascular end points in Japanese elderly hypertensive patients4 and in many other population‐based cohorts 5, 6. In a meta‐analysis of 5645 subjects from 8 cohorts, sleep‐trough MS (STMS) significantly and independently associated with cardiovascular outcomes 5. However, the prognostic value of MS for cardiovascular disease was not confirmed by recent prospective studies 7, 8, 9…”