The International Database of HOme blood pressure in relation to Cardiovascular Outcome (IDHOCO): moving from baseline characteristics to research perspectives

Masked hypertension in a middle-aged population and its relation to manifestations of vascular disease

BACKGROUND

Masked hypertension is associated with cardiovascular disease (CVD). However, previous large studies have not used the same device to measure office and home blood pressure (BP) and adhered to current home BP measurement recommendations of the European Society of Hypertension. We aimed to characterize masked hypertension and explore its relation to manifestations of CVD.

METHODS

A randomly selected cohort of 5057 participants aged 50-64 years from the Swedish CardioPulmonary BioImage Study (SCAPIS) was evaluated with office and home BP using the semi-automatic Omron M10-IT oscillometric device. Additional analyses included pulse wave velocity (PWV) and coronary artery calcium score (CACS).

RESULTS

Of participants, 4122 did not have current antihypertensive treatment, and were thus included in our analyses. Of these, 2634 (63.9%) had sustained normotension, and 172 (4.2%) had masked hypertension. Participants with masked hypertension vs. sustained normotension were more often men (66.9 vs. 46.2%, P  < 0.001). Those with masked hypertension had higher mean PWV [9.3 (95% confidence interval, 95% CI 9.1-9.5) vs. 8.3 (95% CI 8.2-8.4) m/s, P  < 0.001] and odds ratio for CACS at least 100 [1.65 (95% CI 1.02-2.68), P  = 0.040]. These associations were similar in a posthoc analysis of masked hypertension and sustained normotension, matched for age, sex and systolic office BP.

CONCLUSION

Masked hypertension was associated with markers of CVD. This suggests that home BP is a better predictor of risk, even when the recordings are performed with the same measurement device, in a population-based setting with randomized recruitment.

What did we learn from the International Databases on Ambulatory and Home Blood Pressure in Relation to Cardiovascular Outcome?

To assess in individual-person meta-analyses how out-of-office blood pressure (BP) contributes to risk stratification and the management of hypertension, an international consortium set up the International Databases on Ambulatory (IDACO) and Home (IDHOCO) Blood Pressure in Relation to Cardiovascular Outcome. This review summarizes key findings of recent IDACO/IDHOCO articles. Among various BP indexes derived from office and ambulatory BP recordings, the 24-h and nighttime BP level were the best predictors of adverse health outcomes. Second, using the 10-year cardiovascular risk associated with guideline-endorsed office BP thresholds as reference, corresponding thresholds were derived for home and ambulatory BP. Stratified by the underlying cardiovascular risk, the rate of cardiovascular events in white-coat hypertensive patients and matched normotensive controls were not substantially different. The observation that masked hypertension carries a high cardiovascular risk was replicated in Nigerian Blacks, using home BP monitoring. The thresholds for 24-h mean arterial pressure, i.e., the BP component measured by oscillometric devices, delineating normotension, elevated BP and hypertension were <90, 90 to 92 and ≥92 mmHg. At young age, the absolute risk associated with out-of-office BP was low, but the relative risk was high, whereas with advancing age, the relative risk decreased and the absolute risk increased. Using pulse pressure as an exemplary case, the relative risks of death, cardiovascular endpoints and stroke decreased over 3-fold from 55 to 75 years of age, whereas in contrast absolute risk rose 3-fold. In conclusion, IDACO/IDHOCO forcefully support the notion that the pressing need to curb the hypertension pandemic cannot be met without out-of-the-office BP monitoring.

Prevalence and Related Factors of White Coat Hypertension and Masked Hypertension in Shunde District, Southern China

Background: White coat hypertension (WCH) and masked hypertension (MH) can increase the risk of target organ damage. Home blood pressure monitoring is an important method for detecting WCH and MH. However, the prevalence and related factors of WCH and MH in China have been rarely reported.

Objective: To explore the prevalence and related factors associated with white coat hypertension (WCH) and masked hypertension (MH) in Shunde District, Southern China.

Methods: This study recruited subjects from the Physical Examination Center in Shunde Hospital, Southern Medical University. Office blood pressure and home blood pressure values were collected using the home blood pressure monitor with telemedicine device and office blood pressure monitor, and the prevalence of WCH and MH was calculated by the values. Multivariate logistic regression was used to explore the related factors for WCH and MH.

Results: Four-hundred and sixty-one participants (61% male), with an average age of 49 years, were included. The prevalence of WCH and MH was 5.1 and 15.2%, respectively. Multivariate logistic regression analysis showed that smoking (OR = 4.71, 95% CI = 1.05–21.15) and family history of coronary heart disease (OR = 4.51, 95% CI = 1.08–18.93) were associated with higher odds of WCH. The associated factors for higher odds of MH were smoking (OR = 2.83, 95% CI = 1.11–7.23), family history of hypertension (OR = 2.17, 95% CI = 1.11–4.26) and family history of coronary heart disease (OR = 2.82, 95% CI = 1.07–7.45).

Conclusion: WCH and MH are highly prevalent in the Physical Examination Center in Shunde Hospital, Southern Medical University. We found smoking and family history of coronary heart disease were related factors for WCH, and smoking, family history of hypertension and coronary heart disease were associated with the odds of MH. Home blood pressure monitoring with a telemedicine device should be recommended to identity abnormal BP phenotype.

Recent status of self-measured home blood pressure in the Japanese general population: a modern database on self-measured home blood pressure (MDAS)

Despite the clinical usefulness of self-measured home blood pressure (BP), reports on the characteristics of home BP have not been sufficient and have varied due to the measurement conditions in each study. We constructed a database on self-measured home BP, which included five Japanese general populations as subdivided aggregate data that were clustered and meta-analyzed according to sex, age category, and antihypertensive drug treatment at baseline (treated and untreated). The self-measured home BPs were collected after a few minutes of rest in a sitting position: (1) the morning home BP was measured within 1 h of waking, after urination, before breakfast, and before taking antihypertensive medication (if any); and (2) the evening home BP was measured just before going to bed. The pulse rate was simultaneously measured. Eligible data from 2000 onward were obtained. The morning BP was significantly higher in treated participants than in untreated people of the same age category, and the BP difference was more marked in women. Among untreated residents, home systolic/diastolic BPs measured in the morning were higher than those measured in the evening; the differences were 5.7/5.0 mmHg in women (ranges across the cohorts, 5.3-6.8/4.7-5.4 mmHg) and 7.3/7.7 mmHg in men (ranges, 6.4-8.5/7.0-8.7 mmHg). In contrast, the home pulse rate in women and men was 2.4 (range, 1.5-3.7) and 5.6 (range, 4.6-6.6) beats per minute, respectively, higher in the evening than in the morning. We demonstrated the current status of home BP and home pulse rate in relation to sex, age, and antihypertensive treatment status in the Japanese general population. The approach by which fine-clustered aggregate statistics were collected and integrated could address practical issues raised in epidemiological research settings.

Opposing Age-Related Trends in Absolute and Relative Risk of Adverse Health Outcomes Associated With Out-of-Office Blood Pressure

Participant-level meta-analyses assessed the age-specific relevance of office blood pressure to cardiovascular complications, but this information is lacking for out-of-office blood pressure. At baseline, daytime ambulatory (n=12 624) or home (n=5297) blood pressure were measured in 17 921 participants (51.3% women; mean age, 54.2 years) from 17 population cohorts. Subsequently, mortality and cardiovascular events were recorded. Using multivariable Cox regression, floating absolute risk was computed across 4 age bands (≤60, 61-70, 71-80, and >80 years). Over 236 491 person-years, 3855 people died and 2942 cardiovascular events occurred. From levels as low as 110/65 mm Hg, risk log-linearly increased with higher out-of-office systolic/diastolic blood pressure. From the youngest to the oldest age group, rates expressed per 1000 person-years increased (P<0.001) from 4.4 (95% CI, 4.0-4.7) to 86.3 (76.1-96.5) for all-cause mortality and from 4.1 (3.9-4.6) to 59.8 (51.0-68.7) for cardiovascular events, whereas hazard ratios per 20-mm Hg increment in systolic out-of-office blood pressure decreased (P≤0.0033) from 1.42 (1.19-1.69) to 1.09 (1.05-1.12) and from 1.70 (1.51-1.92) to 1.12 (1.07-1.17), respectively. These age-related trends were similar for out-of-office diastolic pressure and were generally consistent in both sexes and across ethnicities. In conclusion, adverse outcomes were directly associated with out-of-office blood pressure in adults. At young age, the absolute risk associated with out-of-office blood pressure was low, but relative risk high, whereas with advancing age relative risk decreased and absolute risk increased. These observations highlight the need of a lifecourse approach for the management of hypertension.

High Home Blood Pressure Variability Associates With Exaggerated Blood Pressure Response to Cold Stress

BACKGROUND

Exaggerated sympathetic cardiovascular (CV) reactivity to stress associates with elevated risk for clinical and preclinical end points of CV disease. It would be useful to identify these individuals, preferably from feasible measurements commonly used in health care. Our study examined the association between home blood pressure (BP) variability and cardiac workload response to whole-body cold exposure.

METHODS

Seventy-five men (55-65 years, 46 hypertensive) measured BP at home twice in the morning and evening for a week. We computed systolic home BP variability as SD of daily means and divided the subjects into groups demonstrating either high or low BP variability. They were exposed to whole-body cold exposure (-10 °C, wind 3 m/second, 15 minutes, winter clothes, standing). BP and heart rate were measured at 3-minute intervals during, and 15 minutes before and after the exposure. Rate-pressure product (RPP) was calculated to represent cardiac workload.

RESULTS

Subjects with high systolic home BP variability demonstrated a greater RPP increase in cold conditions compared to those with low BP variability [mean change from baseline (95% CI): 1,850 (1,450 to 2,250) bpm × mm Hg vs. 930 (610, 1,250) bpm × mm Hg, P < 0.01]. This was related to the augmented systolic BP change [31(28, 35) mm Hg vs. 23(20, 26) mm Hg, P < 0.01]. Home BP variability correlated with cold-related RPP (rS = 0.34, P = 0.003) and systolic BP (rS = 0.38, P < 0.001) responses.

CONCLUSIONS

Moderate whole-body cold exposure increased BP and cardiac workload more among those with higher systolic home BP variability, independently of home BP level. Elevated home BP variability may indicate augmented sympathetically mediated vascular reactivity for environmental stressors.

PUBLIC TRIALS REGISTRY NUMBER

Trial Number NCT02007031.

Prognostic value of average home blood pressure and variability: 19-year follow-up of the Didima study

OBJECTIVE

The current general population study explored the prognostic value of home blood pressure (HBP) average and variability (BPV) versus office measurements (OBP).

METHODS

In 1997, 665 adults of Didima, Argolida, Greece were evaluated with OBP (two visits, six readings) and HBP (3 days, 12 readings) measurements. Total mortality and cardiovascular morbidity and mortality (CVD) were assessed after 19.0 ± 1.4 years. BPV was quantified by using SD and coefficient of variation.

RESULTS

During follow-up, 216 deaths (124 cardiovascular) and 146 cardiovascular events (fatal and nonfatal) were documented. Hazard ratios for total mortality were 1.39/1.20 (P < 0.01/ < 0.01) per 10/5 mmHg increase in systolic/diastolic HBP and 1.36/1.02 (P < 0.01/NS) for OBP (similar hazard ratios for CVD). After adjustment for baseline risk factors, OBP and HBP lost their prognostic ability, except from diastolic OBP that predicted CVD (hazard ratio 1.10, P = 0.03). Sustained, masked and white-coat hypertension were associated with increased risk of death and CVD (P < 0.01 versus normotensive participants). After adjustment, the risk of death remained significant for all, but CVD only for white-coat hypertension. Systolic home BPV (not diastolic) predicted total mortality (adjusted hazard ratios 1.18/1.17 for 1-SD increase in SD/coefficient of variation; P < 0.05) and CVD. Unadjusted systolic/diastolic office BPV predicted CVD outcome (for total mortality only systolic), yet not after adjustment. Systolic home BPV predicted total mortality and CVD independent of office BPV.

CONCLUSION

In this general population study with 19-year follow-up, average HBP predicted total mortality and CVD as reliably as OBP. Only normotension (low OBP and HBP) was associated with low risk. Systolic home BPV exhibited superior prognostic ability than OBP, deserving further research.

More accurate systolic blood pressure measurement is required for improved hypertension management: a perspective

The commonly used techniques for systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurement are the auscultatory Korotkoff-based sphygmomanometry and oscillometry. The former technique is relatively accurate but is limited to a physician's office because its automatic variant is subject to noise artifacts. Consequently, the Korotkoff-based measurement overestimates the blood pressure in some patients due to white coat effect, and because it is a single measurement, it cannot properly represent the variable blood pressure. Automatic oscillometry can be used at home by the patient and is preferred even in clinics. However, the technique's accuracy is low and errors of 10-15 mmHg are common. Recently, we have developed an automatic technique for SBP measurement, based on an arm pressure cuff and a finger photoplethysmographic probe. The technique was found to be significantly more accurate than oscillometry, and comparable to the Korotkoff-based technique, the reference-standard for non-invasive blood pressure measurements. The measurement of SBP is a mainstay for the diagnosis and follow-up of hypertension, which is a major risk factor for several adverse events, mainly cardiovascular. Lowering blood pressure evidently reduces the risk, but excessive lowering can result in hypotension and consequently hypoperfusion to vital organs, since blood pressure is the driving force for blood flow. Erroneous measurement by 10 mmHg can lead to a similar unintended reduction of SBP and may adversely affect patients treated to an SBP of 120-130 mmHg. In particular, in elderly patients, unintended excessive reduction of blood pressure due to inaccurate SBP measurement can result in cerebral hypoperfusion and consequent cognitive decline. By using a more accurate technique for automatic SBP measurement (such as the photoplethysmographic-based technique), the optimal blood pressure target can be achieved with lower risk for hypotension and its adverse events.

Outcome-Driven Thresholds for Increased Home Blood Pressure Variability

Increased blood pressure (BP) variability predicts cardiovascular disease, but lack of operational thresholds limits its use in clinical practice. Our aim was to define outcome-driven thresholds for increased day-to-day home BP variability. We studied a population-based sample of 6238 individuals (mean age 60.0±12.9, 56.4% women) from Japan, Greece, and Finland. All participants self-measured their home BP on ≥3 days. We defined home BP variability as the coefficient of variation of the first morning BPs on 3 to 7 days. We assessed the association between systolic/diastolic BP variability (as a continuous variable and in deciles of coefficient of variation) and cardiovascular outcomes using Cox regression models adjusted for cohort and classical cardiovascular risk factors, including BP. During a follow-up of 9.3±3.6 years, 304 cardiovascular deaths and 715 cardiovascular events occurred. A 1 SD increase in systolic/diastolic home BP variability was associated with increased risk of cardiovascular mortality (hazard ratio, 1.17/1.22; 95% confidence interval, 1.06-1.30/1.11-1.34; P=0.003/<0.0001) and cardiovascular events (hazard ratio, 1.13/1.14; 95% confidence interval, 1.05-1.21/1.07-1.23; P=0.0007/0.0002). Compared with the average risk in the whole population, risk of cardiovascular deaths (hazard ratio, 1.66/1.84; 95% confidence interval, 1.27-2.17/1.42-2.37; P=0.0002/<0.0001) and events (hazard ratio, 1.46/1.42; 95% confidence interval, 1.21-1.76/1.17-1.71; P<0.0001/0.0004) was increased in the highest decile of systolic/diastolic BP variability (coefficient of variation>11.0/12.8). Increased home BP variability predicts cardiovascular outcomes in the general population. Individuals with a systolic/diastolic coefficient of variation of day-to-day home BP >11.0/12.8 may have an increased risk of cardiovascular disease. These findings could help physicians identify individuals who are at an increased cardiovascular disease risk.

Prevalence and Determinants of Masked Hypertension Among Black Nigerians Compared With a Reference Population

Hitherto, diagnosis of hypertension in sub-Saharan Africa was largely based on conventional office blood pressure (BP). Data on the prevalence of masked hypertension (MH) in this region is scarce. Among individuals with normal office BP (<140/90 mm Hg), we compared the prevalence and determinants of MH diagnosed with self-monitored home blood pressure (≥135/85 mm Hg) among 293 Nigerians with a reference population consisting of 3615 subjects enrolled in the International Database on Home Blood Pressure in Relation to Cardiovascular Outcomes. In the reference population, the prevalence of MH was 14.6% overall and 11.1% and 39.6% in untreated and treated participants, respectively. Among Nigerians, the prevalence standardized to the sex and age distribution of the reference population was similar with rates of 14.4%, 8.6%, and 34.6%, respectively. The mutually adjusted odds ratios of having MH in Nigerians were 2.34 (95% confidence interval, 1.39–3.94) for a 10-year higher age, 1.92 (1.11–3.31) and 1.70 (1.14–2.53) for 10- or 5-mm Hg increments in systolic or diastolic office BP, and 3.05 (1.08–8.55) for being on antihypertensive therapy. The corresponding estimates in the reference population were similar with odds ratios of 1.80 (1.62–2.01), 1.64 (1.45–1.87), 1.13 (1.05–1.22), and 2.84 (2.21–3.64), respectively. In conclusion, MH is as common in Nigerians as in other populations with older age and higher levels of office BP being major risk factors. A significant proportion of true hypertensive subjects therefore remains undetected based on office BP, which is particularly relevant in sub-Saharan Africa, where hypertension is now a major cause of death.

The design, rationale, and baseline characteristics of a nationwide cohort registry in China: blood pressure and clinical outcome in TIA or ischemic stroke

BACKGROUND

The relationship between poststroke blood pressure (BP) and clinical outcomes in ischemic stroke (IS) is still controversial. However, there is no large BP database for IS or transient ischemic attack (TIA) in China. This study aims to describe the rationale, study design, and baseline characteristics of a nationwide BP database in IS or TIA patients in China.

MATERIALS AND METHODS

The BOSS (blood pressure and clinical outcome in TIA or ischemic stroke) study was a hospital-based, prospective cohort study aiming to assess BP parameters and clinical outcome in IS/TIA patients. BP parameters were based on office BP, ambulatory BP, and home BP. Clinical outcomes included stroke recurrence, combined vascular events, and disability. Electronic case-report forms were used to record baseline and follow-up data. The patients were followed up for clinical outcomes at 3 months through face-to-face interview and at 12 months by telephone.

RESULTS

Between October 2012 and February 2014, the BOSS registry recruited 2,608 patients from 61 hospitals, with a mean age of 62.5 years, 32.4% of whom were female, 88.9% with an entry diagnosis of IS, and 86% diagnosed with hypertension. The rates of patients lost-to-follow-up were 3.1% at 3 months and 5.1% at 1 year; 93% of patients completed ambulatory BP monitoring during hospitalization and 94.7% finished a 3-month BP diary.

CONCLUSION

The BOSS registry will provide important evidence about BP management in the acute phase and secondary prevention for IS/TIA patients.

Optimal number of days for home blood pressure measurement

BACKGROUND

Current guidelines make no outcome-based recommendations on the optimal measurement schedule for home blood pressure (BP).

METHODS

We enrolled 4,802 randomly recruited participants from three populations. The participants were classified by their (i) cross-classification according to office and home BP (normotension, masked hypertension, white-coat hypertension, and sustained hypertension) and (ii) home BP level (normal BP, high normal BP, grade 1 and 2 hypertension), while the number of home measurement days was increased from 1 to 7. The prognostic accuracy of home BP with an increasing number of home BP measurement days was also assessed by multivariable-adjusted Cox models.

RESULTS

Agreement in classification between consecutive measurement days indicated near perfect agreement (κ ≥ 0.9) after the sixth measurement day for both office and home BP cross-classification (97.8% maintained classification, κ = 0.97) and home BP level (93.6% maintained classification, κ = 0.91). Over a follow-up of 8.3 years, 568 participants experienced a cardiovascular event, and the first home BP measurement alone predicted events significantly (P ≤ 0.003). The confidence intervals (CIs) were too wide and overlapping to show superiority of multiple measurement days over the first measurement day (hazard ratios per 10mm Hg increase in systolic BP at initial day, 1.11 [CI 1.07-1.16]; that at 1-7 days, 1.18 [CI 1.12-1.24]). Masked hypertension, but not white-coat hypertension, was associated with increased cardiovascular risk, irrespective of the number of home measurement days.

CONCLUSION

Even a single home BP measurement is a potent predictor of cardiovascular events, whereas seven home measurement days may be needed to reliably diagnose hypertension.

Is home blood pressure monitoring useful in the management of patients with resistant hypertension?

BACKGROUND

Ambulatory blood pressure (BP) monitoring (ABPM) is a cornerstone in resistant hypertension (RHT) management. However, it has higher cost and lower patients' acceptance than home BP monitoring (HBPM). Our objective was to evaluate HBPM usefulness in the management of patients with RHT.

METHODS

A total of 240 patients were submitted to 24-hour ABPM and 5-day HBPM (triplicate morning and evening measurements). Patients with uncontrolled office BP (≥140/90mm Hg) were classified as true RHT (daytime or home BP ≥135/85mm Hg) or white-coat RHT (daytime or home BP <135/85mm Hg), and patients with controlled office BP were classified as masked RHT (daytime or home BP ≥135/85mm Hg) or controlled RHT (daytime or home BP <135/85mm Hg). Sensitivity, specificity, predictive values, and likelihood ratios for HBPM were calculated. Agreement between the procedures was evaluated using kappa coefficients and the Bland-Altman method.

RESULTS

Mean office BP was 157±26/84±16mm Hg, mean daytime BP was 134±18/77±13mm Hg, and mean home BP was 143±20/76±14mm Hg. The ABPM and HBPM diagnoses were 35% and 48%, respectively, for true RHT; 36% and 23%, respectively, for white-coat RHT; 7% and 17%, respectively, for masked RHT; and 22% and 13%, respectively, for controlled RHT. HBPM overestimated systolic BP by 8.8 (95% confidence interval (CI) = 6.8-10.7) mm Hg and diastolic BP by 0.2 (95% CI = -1.0 to 1.4) mm Hg. The specificity, sensitivity, and positive and negative predictive values of HBPM in detecting controlled ambulatory BP were 91%, 55%, 89%, and 59%.

CONCLUSIONS

HBPM presented good agreement with ABPM and can be used as a complementary method in the follow-up of resistant hypertensive patients, particularly in those with controlled ambulatory BPs.

Thresholds for conventional and home blood pressure by sex and age in 5018 participants from 5 populations

Whether blood pressure thresholds for hypertension should differ according to sex or age remains debated. We did a subject-level meta-analysis of 5018 people untreated for hypertension and randomly recruited from 5 populations (women, 56.7%; ≥60 years, 42.3%). We used multivariable-adjusted Cox regression and a bootstrap procedure to determine home blood pressure (HBP) levels yielding 10-year cardiovascular risks similar to those associated with established systolic/diastolic thresholds (140-160/80-100 mm Hg) for the conventional blood pressure (CBP). Conversely, we estimated CBP thresholds providing 10-year cardiovascular risks similar to those associated established HBP levels (125-135/80-85 mm Hg). All analyses were stratified for sex and age (<60 versus ≥60 years). During 8.3 years (median), 414 participants experienced a cardiovascular event. The sex differences between HBP thresholds derived from CBP and between CBP thresholds derived from HBP were all nonsignificant (P≥0.24), ranging from -4.6 to 3.6 mm Hg systolic and from -4.3 to 2.1 mm Hg diastolic. The age differences between HBP thresholds derived from CBP and between CBP thresholds derived from HBP ranged from -6.7 to 8.4 mm Hg systolic and from -1.9 to 1.7 mm Hg diastolic and were nonsignificant (P≥0.08), except for HBP thresholds derived from CBP levels of 140 mm Hg systolic and 80 mm Hg diastolic (P≤0.04). Sensitivity analyses based on cardiac or cerebrovascular complications were confirmatory. In conclusion, our findings based on outcome-driven criteria support contemporary guidelines that propose single blood pressure thresholds that can be indiscriminately applied in both sexes and across the age range.

Practical use of home blood pressure monitoring in chronic kidney disease

Despite the availability of blood pressure (BP)-lowering medications and dietary education, hypertension is still poorly controlled in the chronic kidney disease (CKD) population. As glomerular filtration rate declines, the number of medications required to achieve BP targets increases, which may lead to reduced patient adherence and therapeutic inertia by the clinician. Home BP monitoring (HBPM) has emerged as a means of improving diagnostic accuracy, risk stratification, patient adherence, and therapeutic intervention. The definition of hypertension by HBPM is an average BP >135/85 mm Hg. Twelve readings over the course of 3-5 days are sufficient for clinical decision making. Diagnostic accuracy is especially important in the CKD population as approximately half of these patients have either white coat hypertension or masked hypertension. Preliminary data suggest that HBPM outperforms office BP monitoring in predicting progression to end-stage renal disease or death. When combined with additional support such as telemonitoring, medication titration, or behavioral therapy, HBPM results in a sustained improvement in BP control. HBPM must be adapted to provide information on the phenomena of nondipping (absence of nocturnal fall in BP) and reverse dipping (paradoxical increase in BP at night). These diurnal patterns are more prevalent in the CKD population and are important cardiovascular risk factors. Ambulatory BP monitoring provides nocturnal BP readings and unlike HBPM may be reimbursed by Medicare when certain criteria are met. Further studies are needed to determine whether HBPM is cost-effective in the current US healthcare system.

Prognosis of white-coat and masked hypertension: International Database of HOme blood pressure in relation to Cardiovascular Outcome

Home blood pressure monitoring is useful in detecting white-coat and masked hypertension and is recommended for patients with suspected or treated hypertension. The prognostic significance of white-coat and masked hypertension detected by home measurement was investigated in 6458 participants from 5 populations enrolled in the International Database of HOme blood pressure in relation to Cardiovascular Outcomes. During a median follow-up of 8.3 years, 714 fatal plus nonfatal cardiovascular events occurred. Among untreated subjects (n=5007), cardiovascular risk was higher in those with white-coat hypertension (adjusted hazard ratio 1.42; 95% CI [1.06-1.91]; P=0.02), masked hypertension (1.55; 95% CI [1.12-2.14]; P<0.01) and sustained hypertension (2.13; 95% CI [1.66-2.73]; P<0.0001) compared with normotensive subjects. Among treated patients (n=1451), the cardiovascular risk did not differ between those with high office and low home blood pressure (white-coat) and treated controlled subjects (low office and home blood pressure; 1.16; 95% CI [0.79-1.72]; P=0.45). However, treated subjects with masked hypertension (low office and high home blood pressure; 1.76; 95% CI [1.23-2.53]; P=0.002) and uncontrolled hypertension (high office and home blood pressure; 1.40; 95% CI [1.02-1.94]; P=0.04) had higher cardiovascular risk than treated controlled patients. In conclusion, white-coat hypertension assessed by home measurements is a cardiovascular risk factor in untreated but not in treated subjects probably because the latter receive effective treatment on the basis of their elevated office blood pressure. In contrast, masked uncontrolled hypertension is associated with increased cardiovascular risk in both untreated and treated patients, who are probably undertreated because of their low office blood pressure.

Risk stratification by self-measured home blood pressure across categories of conventional blood pressure: a participant-level meta-analysis

BACKGROUND

The Global Burden of Diseases Study 2010 reported that hypertension is worldwide the leading risk factor for cardiovascular disease, causing 9.4 million deaths annually. We examined to what extent self-measurement of home blood pressure (HBP) refines risk stratification across increasing categories of conventional blood pressure (CBP).

METHODS AND FINDINGS

This meta-analysis included 5,008 individuals randomly recruited from five populations (56.6% women; mean age, 57.1 y). All were not treated with antihypertensive drugs. In multivariable analyses, hazard ratios (HRs) associated with 10-mm Hg increases in systolic HBP were computed across CBP categories, using the following systolic/diastolic CBP thresholds (in mm Hg): optimal, <120/<80; normal, 120-129/80-84; high-normal, 130-139/85-89; mild hypertension, 140-159/90-99; and severe hypertension, ≥160/≥100. Over 8.3 y, 522 participants died, and 414, 225, and 194 had cardiovascular, cardiac, and cerebrovascular events, respectively. In participants with optimal or normal CBP, HRs for a composite cardiovascular end point associated with a 10-mm Hg higher systolic HBP were 1.28 (1.01-1.62) and 1.22 (1.00-1.49), respectively. At high-normal CBP and in mild hypertension, the HRs were 1.24 (1.03-1.49) and 1.20 (1.06-1.37), respectively, for all cardiovascular events and 1.33 (1.07-1.65) and 1.30 (1.09-1.56), respectively, for stroke. In severe hypertension, the HRs were not significant (p≥0.20). Among people with optimal, normal, and high-normal CBP, 67 (5.0%), 187 (18.4%), and 315 (30.3%), respectively, had masked hypertension (HBP≥130 mm Hg systolic or ≥85 mm Hg diastolic). Compared to true optimal CBP, masked hypertension was associated with a 2.3-fold (1.5-3.5) higher cardiovascular risk. A limitation was few data from low- and middle-income countries.

CONCLUSIONS

HBP substantially refines risk stratification at CBP levels assumed to carry no or only mildly increased risk, in particular in the presence of masked hypertension. Randomized trials could help determine the best use of CBP vs. HBP in guiding BP management. Our study identified a novel indication for HBP, which, in view of its low cost and the increased availability of electronic communication, might be globally applicable, even in remote areas or in low-resource settings.

Cardiovascular dysfunctions and sympathovagal imbalance in hypertension and prehypertension: physiological perspectives

Hypertension (HTN) and prehypertension (pre-HTN) have been identified as independent risk factors for adverse cardiovascular events. Recently, increased psychosocial stress and work stress have contributed to the increased prevalence of HTN and pre-HTN, in addition to the contribution of obesity, diabetes, poor food habits and physical inactivity. Irrespective of the etiology, sympathetic overactivity has been recognized as the main pathophysiologic mechanism in the genesis of HTN and pre-HTN. Sympathovagal imbalance owing to sympathetic overactivity and vagal withdrawal is reported to be the basis of many clinical disorders. However, the role played by vagal withdrawal has been under-reported. In this review, we have analyzed the pathophysiologic involvement of sympathovagal imbalance in the development of HTN and pre-HTN, and the link of sympathovagal imbalance to cardiovascular dysfunctions. We have emphasized that adaptation to a healthier lifestyle will help improve sympathovagal homeostasis and prevent the occurrence of HTN and pre-HTN.

Risk stratification by 24-hour ambulatory blood pressure and estimated glomerular filtration rate in 5322 subjects from 11 populations

No previous study addressed whether in the general population estimated glomerular filtration rate (eGFR [Chronic Kidney Disease Epidemiology Collaboration formula]) adds to the prediction of cardiovascular outcome over and beyond ambulatory blood pressure. We recorded health outcomes in 5322 subjects (median age, 51.8 years; 43.1% women) randomly recruited from 11 populations, who had baseline measurements of 24-hour ambulatory blood pressure (ABP(24)) and eGFR. We computed hazard ratios using multivariable-adjusted Cox regression. Median follow-up was 9.3 years. In fully adjusted models, which included both ABP(24) and eGFR, ABP(24) predicted (P≤0.008) both total (513 deaths) and cardiovascular (206) mortality; eGFR only predicted cardiovascular mortality (P=0.012). Furthermore, ABP(24) predicted (P≤0.0056) fatal combined with nonfatal events as a result of all cardiovascular causes (555 events), cardiac disease (335 events), or stroke (218 events), whereas eGFR only predicted the composite cardiovascular end point and stroke (P≤0.035). The interaction terms between ABP(24) and eGFR were all nonsignificant (P≥0.082). For cardiovascular mortality, the composite cardiovascular end point, and stroke, ABP(24) added 0.35%, 1.17%, and 1.00% to the risk already explained by cohort, sex, age, body mass index, smoking and drinking, previous cardiovascular disease, diabetes mellitus, and antihypertensive drug treatment. Adding eGFR explained an additional 0.13%, 0.09%, and 0.14%, respectively. Sensitivity analyses stratified for ethnicity, sex, and the presence of hypertension or chronic kidney disease (eGFR <60 mL/min per 1.73 m(2)) were confirmatory. In conclusion, in the general population, eGFR predicts fewer end points than ABP(24). Relative to ABP(24), eGFR is as an additive, not a multiplicative, risk factor and refines risk stratification 2- to 14-fold less.

Outcome-driven thresholds for home blood pressure measurement: international database of home blood pressure in relation to cardiovascular outcome

The lack of outcome-driven operational thresholds limits the clinical application of home blood pressure (BP) measurement. Our objective was to determine an outcome-driven reference frame for home BP measurement. We measured home and clinic BP in 6470 participants (mean age, 59.3 years; 56.9% women; 22.4% on antihypertensive treatment) recruited in Ohasama, Japan (n=2520); Montevideo, Uruguay (n=399); Tsurugaya, Japan (n=811); Didima, Greece (n=665); and nationwide in Finland (n=2075). In multivariable-adjusted analyses of individual subject data, we determined home BP thresholds, which yielded 10-year cardiovascular risks similar to those associated with stages 1 (120/80 mm Hg) and 2 (130/85 mm Hg) prehypertension, and stages 1 (140/90 mm Hg) and 2 (160/100 mm Hg) hypertension on clinic measurement. During 8.3 years of follow-up (median), 716 cardiovascular end points, 294 cardiovascular deaths, 393 strokes, and 336 cardiac events occurred in the whole cohort; in untreated participants these numbers were 414, 158, 225, and 194, respectively. In the whole cohort, outcome-driven systolic/diastolic thresholds for the home BP corresponding with stages 1 and 2 prehypertension and stages 1 and 2 hypertension were 121.4/77.7, 127.4/79.9, 133.4/82.2, and 145.4/86.8 mm Hg; in 5018 untreated participants, these thresholds were 118.5/76.9, 125.2/79.7, 131.9/82.4, and 145.3/87.9 mm Hg, respectively. Rounded thresholds for stages 1 and 2 prehypertension and stages 1 and 2 hypertension amounted to 120/75, 125/80, 130/85, and 145/90 mm Hg, respectively. Population-based outcome-driven thresholds for home BP are slightly lower than those currently proposed in hypertension guidelines. Our current findings could inform guidelines and help clinicians in diagnosing and managing patients.