Kalina Kawecka-Jaszcz

Fatal and Nonfatal Outcomes, Incidence of Hypertension, and Blood Pressure Changes in Relation to Urinary Sodium Excretion

CONTEXT Extrapolations from observational studies and short-term intervention trials suggest that population-wide moderation of salt intake might reduce cardiovascular events. OBJECTIVE To assess whether 24-hour urinary sodium excretion predicts blood pressure (BP) and health outcomes. DESIGN, SETTING, AND PARTICIPANTS Prospective population study, involving 3681 participants without cardiovascular disease (CVD) who are members of families that were randomly enrolled in the Flemish Study on Genes, Environment, and Health Outcomes (1985-2004) or in the European Project on Genes in Hypertension (1999-2001). Of 3681 participants without CVD, 2096 were normotensive at baseline and 1499 had BP and sodium excretion measured at baseline and last follow-up (2005-2008). MAIN OUTCOME MEASURES Incidence of mortality and morbidity and association between changes in BP and sodium excretion. Multivariable-adjusted hazard ratios (HRs) express the risk in tertiles of sodium excretion relative to average risk in the whole study population. RESULTS Among 3681 participants followed up for a median 7.9 years, CVD deaths decreased across increasing tertiles of 24-hour sodium excretion, from 50 deaths in the low (mean, 107 mmol), 24 in the medium (mean, 168 mmol), and 10 in the high excretion group (mean, 260 mmol; P < .001), resulting in respective death rates of 4.1% (95% confidence interval [CI], 3.5%-4.7%), 1.9% (95% CI, 1.5%-2.3%), and 0.8% (95% CI, 0.5%-1.1%). In multivariable-adjusted analyses, this inverse association retained significance (P = .02): the HR in the low tertile was 1.56 (95% CI, 1.02-2.36; P = .04). Baseline sodium excretion predicted neither total mortality (P = .10) nor fatal combined with nonfatal CVD events (P = .55). Among 2096 participants followed up for 6.5 years, the risk of hypertension did not increase across increasing tertiles (P = .93). Incident hypertension was 187 (27.0%; HR, 1.00; 95% CI, 0.87-1.16) in the low, 190 (26.6%; HR, 1.02; 95% CI, 0.89-1.16) in the medium, and 175 (25.4%; HR, 0.98; 95% CI, 0.86-1.12) in the high sodium excretion group. In 1499 participants followed up for 6.1 years, systolic blood pressure increased by 0.37 mm Hg per year (P < .001), whereas sodium excretion did not change (-0.45 mmol per year, P = .15). However, in multivariable-adjusted analyses, a 100-mmol increase in sodium excretion was associated with 1.71 mm Hg increase in systolic blood pressure (P.<001) but no change in diastolic BP. CONCLUSIONS In this population-based cohort, systolic blood pressure, but not diastolic pressure, changes over time aligned with change in sodium excretion, but this association did not translate into a higher risk of hypertension or CVD complications. Lower sodium excretion was associated with higher CVD mortality.

Prognostic Value of Reading-to-Reading Blood Pressure Variability Over 24 Hours in 8938 Subjects From 11 Populations

In previous studies, of which several were underpowered, the relation between cardiovascular outcome and blood pressure (BP) variability was inconsistent. We followed health outcomes in 8938 subjects (mean age: 53.0 years; 46.8% women) randomly recruited from 11 populations. At baseline, we assessed BP variability from the SD and average real variability in 24-hour ambulatory BP recordings. We computed standardized hazard ratios (HRs) while stratifying by cohort and adjusting for 24-hour BP and other risk factors. Over 11.3 years (median), 1242 deaths (487 cardiovascular) occurred, and 1049, 577, 421, and 457 participants experienced a fatal or nonfatal cardiovascular, cardiac, or coronary event or a stroke. Higher diastolic average real variability in 24-hour ambulatory BP recordings predicted (P≤0.03) total (HR: 1.14) and cardiovascular (HR: 1.21) mortality and all types of fatal combined with nonfatal end points (HR: ≥1.07) with the exception of cardiac and coronary events (HR: ≤1.02; P≥0.58). Higher systolic average real variability in 24-hour ambulatory BP recordings predicted (P<0.05) total (HR: 1.11) and cardiovascular (HR: 1.16) mortality and all fatal combined with nonfatal end points (HR: ≥1.07), with the exception of cardiac and coronary events (HR: ≤1.03; P≥0.54). SD predicted only total and cardiovascular mortality. While accounting for the 24-hour BP level, average real variability in 24-hour ambulatory BP recordings added <1% to the prediction of a cardiovascular event. Sensitivity analyses considering ethnicity, sex, age, previous cardiovascular disease, antihypertensive treatment, number of BP readings per recording, or the night:day BP ratio were confirmatory. In conclusion, in a large population cohort, which provided sufficient statistical power, BP variability assessed from 24-hour ambulatory recordings did not contribute much to risk stratification over and beyond 24-hour BP.

Comparison of aortic pulse wave velocity measured by three techniques: Complior, SphygmoCor and Arteriograph.

Background New 2007 European Society of Hypertension guidelines recommend measuring arterial stiffness in patients with arterial hypertension, suggesting a carotid–femoral pulse wave velocity over 12 m/s as an estimate of subclinical organ damage. Considering this cutoff point, it is worth exploring whether or not there are significant differences in results obtained using various techniques for measuring aortic pulse wave velocity. The aim of the study was to compare aortic pulse wave velocity measurements using Complior, SphygmoCor, and Arteriograph devices, and to assess the effect of pulse wave transit time and traveled distance on pulse wave velocity values. Methods Aortic pulse wave velocity was measured on a single visit, using these devices, in randomized order, in a group of 64 patients with grade 1 or 2 arterial hypertension. Results Aortic pulse wave velocity measured using Complior (10.1 ± 1.7 m/s) was significantly higher than that obtained using SphygmoCor (8.1 ± 1.1 m/s) or Arteriograph (8.6 ± 1.3 m/s). No differences were noted between pulse wave velocity measurements using SphygmoCor and Arteriograph. Between-method comparison revealed that differences in traveled distance were significant: Complior versus Arteriograph [0.09 m, Confidence interval (CI): 0.08–0.12 m, P < 0.05], Complior versus SphygmoCor (0.15 m, CI: 0.13–0.16 m, P < 0.05), Arteriograph versus SphygmoCor (0.05 m, CI: 0.03–0.07 m, P < 0.05). No between-method differences were found for transit times. Conclusion Differences in pulse wave velocity obtained by compared devices resulted primarily from using various methods for measuring traveled distance. It appears reasonable to establish uniform principles for the measurement of traveled distance. Because a large number of prognosis/survival studies used direct distance between carotid and femoral sites of pulse wave recording, this distance should be mostly recommended.

Pulsatile but Not Steady Component of Blood Pressure Predicts Cardiovascular Events in Coronary Patients

Although the differences between central and peripheral blood pressure (BP) values have been known for decades, the consequences of decision making based on peripheral rather than central BP have only recently been recognized. There are only a few studies assessing the relationship between intraaortic BP and cardiovascular risk. In addition, the relationship between central BP and the risk of cardiovascular events in a large group of coronary patients has not yet been evaluated. Therefore, the aim of the study was to determine the prognostic significance of central BP-derived indices in patients undergoing coronary angiography. Invasive central BPs were taken at baseline, and study end points were ascertained during over a 4.5-year follow-up in 1109 consecutive patients. The primary end point (cardiovascular death or myocardial infarction or stroke or cardiac arrest or heart transplantation or myocardial revascularization) occurred in 246 (22.2%) patients. Central pulsatility was the most powerful predictor of the primary end point (hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.14 to 1.48). Central pulse pressure was also independently related to the primary end point (HR 1.25, 95% CI 1.09 to 1.43). Central mean BP as well as peripheral BP parameters were not independently related to the primary end point risk. Central pulsatility was also related to risk of cardiovascular death or myocardial infarction or stroke. The pulsatile component of BP is the most important factor related to the cardiovascular risk in coronary patients. It is more closely associated with cardiovascular risk than steady component of BP.

Prognostic value of isolated nocturnal hypertension on ambulatory measurement in 8711 individuals from 10 populations

Background We and other investigators previously reported that isolated nocturnal hypertension on ambulatory measurement (INH) clustered with cardiovascular risk factors and was associated with intermediate target organ damage. We investigated whether INH might also predict hard cardiovascular endpoints. Methods and results We monitored blood pressure (BP) throughout the day and followed health outcomes in 8711 individuals randomly recruited from 10 populations (mean age 54.8 years, 47.0% women). Of these, 577 untreated individuals had INH (daytime BP <135/85 mmHg and night-time BP ≥120/70 mmHg) and 994 untreated individuals had isolated daytime hypertension on ambulatory measurement (IDH; daytime BP ≥135/85 mmHg and night-time BP <120/70 mmHg). During follow-up (median 10.7 years), 1284 deaths (501 cardiovascular) occurred and 1109 participants experienced a fatal or nonfatal cardiovascular event. In multivariable-adjusted analyses, compared with normotension (n = 3837), INH was associated with a higher risk of total mortality (hazard ratio 1.29, P = 0.045) and all cardiovascular events (hazard ratio 1.38, P = 0.037). IDH was associated with increases in all cardiovascular events (hazard ratio 1.46, P = 0.0019) and cardiac endpoints (hazard ratio 1.53, P = 0.0061). Of 577 patients with INH, 457 were normotensive (<140/90 mmHg) on office BP measurement. Hazard ratios associated with INH with additional adjustment for office BP were 1.31 (P = 0.039) and 1.38 (P = 0.044) for total mortality and all cardiovascular events, respectively. After exclusion of patients with office hypertension, these hazard ratios were 1.17 (P = 0.31) and 1.48 (P = 0.034). Conclusion INH predicts cardiovascular outcome in patients who are normotensive on office or on ambulatory daytime BP measurement.

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

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 1.32 (95% CI: 1.09 to 1.59; P=0.004) in the top decile of the systolic sleep-through MS (≥37.0 mm Hg). For cardiovascular and noncardiovascular death, these hazard ratios were 1.18 (95% CI: 0.87 to 1.61; P=0.30) and 1.42 (95% CI: 1.11 to 1.80; P=0.005). For all cardiovascular, cardiac, coronary, and cerebrovascular events, the hazard ratios in the top decile of the systolic sleep-through MS were 1.30 (95% CI: 1.06 to 1.60; P=0.01), 1.52 (95% CI: 1.15 to 2.00; P=0.004), 1.45 (95% CI: 1.04 to 2.03; P=0.03), and 0.95 (95% CI: 0.68 to 1.32; P=0.74), respectively. Analysis of the preawakening systolic MS and the diastolic MS generated consistent results. In conclusion, a MS above the 90th percentile significantly and independently predicted cardiovascular outcome and might contribute to risk stratification by ambulatory blood pressure monitoring.

A new method for assessing 24-h blood pressure variability after excluding the contribution of nocturnal blood pressure fall.

Objectives To assess quantitatively the relationship between nocturnal blood pressure (BP) fall and 24-h BP variability; to propose a new method for computing 24-h BP variability, devoid of the contribution from nocturnal BP fall; and to verify the clinical value of this method. Methods and results We analysed 3863 ambulatory BP recordings, and computed: (1) the standard deviation (SD) of 24-h BP directly from all individual readings and as a weighted mean of daytime and night-time SD (wSD); and (2) the size of nocturnal BP fall. Left ventricular mass index (LVMI) was assessed by echocardiography in 339 of the patients. The 24-h SD of BP was significantly greater than the 24-h wSD. Nocturnal BP fall was strongly and directly related to 24-h SD, the relationship with 24-h wSD being much weaker and inverse. The difference between SD and wSD was almost exclusively determined by the size of nocturnal BP fall. wSD of systolic BP was significantly related to LVMI, while 24-h SD was not. Conclusion Conventional 24-h SD of BP is markedly influenced by nocturnal BP fall. The weighted 24-h SD of BP removes the mathematical interference from night-time BP fall and correlates better with end-organ damage, therefore it may be considered as a simple index of 24-h BP variability superior to conventional 24-h SD.

Significance of White-Coat Hypertension in Older Persons With Isolated Systolic Hypertension: A Meta-Analysis Using the International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes Population

The significance of white-coat hypertension in older persons with isolated systolic hypertension remains poorly understood. We analyzed subjects from the population-based 11-country International Database on Ambulatory Blood Pressure Monitoring in Relation to Cardiovascular Outcomes database who had daytime ambulatory blood pressure (BP; ABP) and conventional BP (CBP) measurements. After excluding persons with diastolic hypertension by CBP (≥90 mm Hg) or by daytime ABP (≥85 mm Hg), a history of cardiovascular disease, and persons <18 years of age, the present analysis totaled 7295 persons, of whom 1593 had isolated systolic hypertension. During a median follow-up of 10.6 years, there was a total of 655 fatal and nonfatal cardiovascular events. The analyses were stratified by treatment status. In untreated subjects, those with white-coat hypertension (CBP ≥140/<90 mm Hg and ABP <135/<85 mm Hg) and subjects with normal BP (CBP <140/<90 mm Hg and ABP <135/<85 mm Hg) were at similar risk (adjusted hazard rate: 1.17 [95% CI: 0.87–1.57]; P=0.29). Furthermore, in treated subjects with isolated systolic hypertension, the cardiovascular risk was similar in elevated conventional and normal daytime systolic BP as compared with those with normal conventional and normal daytime BPs (adjusted hazard rate: 1.10 [95% CI: 0.79–1.53]; P=0.57). However, both treated isolated systolic hypertension subjects with white-coat hypertension (adjusted hazard rate: 2.00; [95% CI: 1.43–2.79]; P<0.0001) and treated subjects with normal BP (adjusted hazard rate: 1.98 [95% CI: 1.49–2.62]; P<0.0001) were at higher risk as compared with untreated normotensive subjects. In conclusion, subjects with sustained hypertension who have their ABP normalized on antihypertensive therapy but with residual white-coat effect by CBP measurement have an entity that we have termed, “treated normalized hypertension.” Therefore, one should be cautious in applying the term “white-coat hypertension” to persons receiving antihypertensive treatment.

Quality control of the blood pressure phenotype in the European Project on Genes in Hypertension.

ObjectivesIn the European Project on Genes in Hypertension (EPOGH) standardized epidemiological methods were used to determine complex phenotypes consisting of blood pressure (BP) in combination with other traits. In this report, we present the quality control of one of the BP phenotypes. MethodsIn seven European countries eight different research groups recruited random samples of nuclear families. Trained observers measured the BP five times consecutively with the participants in the seated position at each of two separate home visits, 1 to 3 weeks apart, according to the guidelines of the British Hypertension Society. Quality assurance and quality control of this BP phenotype were implemented according to detailed instructions defined in the protocol of the EPOGH study. ResultsOn 31 August 2001, BP measurements of 2476 subjects were available for analysis. Fewer BP readings than the five planned per visit occurred in one of the eight centres, but only in 0.4% of the home visits. Across centres the relative frequency of identical consecutive readings for systolic or diastolic blood pressure varied from 0 to 6%. The occurrence of odd readings ranged from 0 to 0.1%. Of the 49 488 systolic and diastolic BP readings, 24.0% ended on a zero (expected 20%). In most EPOGH centres there was a progressive decline in the BP from the first to the second home visit. Overall, these decreases averaged 2.36 mmHg [95% confidence interval (CI): 1.98–2.74, P  < 0.001] for systolic BP and 1.74 mmHg (95% CI: 1.46–2.02, P  < 0.001) for diastolic BP. ConclusionsQuality assurance and control should be planned at the design stage of a project involving BP measurement and implemented from its very beginnings until the end. The procedures of quality assurance set up in the EPOGH study for the BP measurements resulted in a well-defined BP phenotype, which was consistent across centres.

The International Database of Ambulatory Blood Pressure in relation to Cardiovascular Outcome (IDACO): protocol and research perspectives.

ObjectivesThe International Database on Ambulatory Blood Pressure Monitoring (1993–1994) lacked a prospective dimension. We are constructing a new resource of longitudinal population studies to investigate with great precision to what extent the ambulatory blood pressure improves risk stratification. MethodsThe acronym IDACO refers to the new International Database of Ambulatory blood pressure in relation to Cardiovascular Outcome. Eligible studies are population based, have fatal as well as nonfatal outcomes available for analysis, comply with ethical standards, and have been previously published in peer-reviewed journals. In a meta-analysis based on individual patient data, composite and cause-specific cardiovascular events will be related to various indexes derived by ambulatory blood pressure monitoring. The analyses will be stratified by cohort and adjusted for the conventional blood pressure and other cardiovascular risk factors. ResultsTo date, the international database includes 7609 patients from four cohorts recruited in Copenhagen, Denmark (n=2311), Noorderkempen, Belgium (n=2542), Ohasama, Japan (n=1535), and Uppsala, Sweden (n=1221). In these four cohorts, during a total of 69 295 person-years of follow-up (median 9.3 years), 1026 patients died and 929 participants experienced a fatal or nonfatal cardiovascular event. Follow-up in five other eligible cohorts, involving a total of 4027 participants, is still in progress. We expect that this follow-up will be completed by the end of 2007. ConclusionThe international database of ambulatory blood pressure in relation to cardiovascular outcome will provide a shared resource to investigate risk stratification by ambulatory blood pressure monitoring to an extent not possible in any earlier individual study.