Is home blood pressure variability itself an interventional target beyond lowering mean home blood pressure during anti-hypertensive treatment?

Annual reports on hypertension research 2020

In 2020, 199 papers were published in Hypertension Research. Many excellent papers have contributed to progress in research on hypertension. Here, our editorial members have summarized eleven topics from published work and discussed current topics in depth. We hope you enjoy our special feature, Annual Reports on Hypertension Research.

Home blood pressure monitoring: methodology, clinical relevance and practical application: a 2021 position paper by the Working Group on Blood Pressure Monitoring and Cardiovascular Variability of the European Society of Hypertension

The present paper provides an update of previous recommendations on Home Blood Pressure Monitoring from the European Society of Hypertension (ESH) Working Group on Blood Pressure Monitoring and Cardiovascular Variability sequentially published in years 2000, 2008 and 2010. This update has taken into account new evidence in this field, including a recent statement by the American Heart association, as well as technological developments, which have occurred over the past 20 years. The present document has been developed by the same ESH Working Group with inputs from an international team of experts, and has been endorsed by the ESH.

Associations Between Day-by-Day Home Blood Pressure Variability and Renal Function and Albuminuria in Patients With and Without Diabetes

BACKGROUND

The phenotype of diabetic kidney disease represents a lower estimated glomerular filtration rate (eGFR) and albuminuria. We investigated the association between day-by-day home blood pressure (BP) variability and the eGFR in subjects with diabetes and compared this association with that in subjects without diabetes. We then attempted to determine whether the association is present in albuminuria.

METHODS

We analyzed 4,231 patients with risk factors of cardiovascular disease (24.4% with diabetes) from the J-HOP (Japan Morning Surge-Home Blood Pressure) study. Home BP was measured in the morning and evening for 14 days. We calculated the SD, coefficient of variation, average real variability (ARV), and variation independent of the mean of the subjects' morning and evening home systolic BP (SBP) as the indexes of day-by-day home BP variability.

RESULTS

A multiple linear regression analysis adjusted for covariates showed both average morning and evening SBP were associated with the log-transformed urine albumin-to-creatinine ratio (UACR) with and without diabetes (all P < 0.05), but not with the eGFR except for an association of average evening SBP in the no-diabetes group. None of the indexes of day-by-day morning and evening home SBP variability were associated with the log-transformed UACR except for the association between the ARV of home morning SBP in the diabetes group. All of the indexes of day-by-day morning and evening home SBP variability were associated with the eGFR only in the diabetes group (all P < 0.05).

CONCLUSIONS

The association between increased day-by-day home BP variability and impaired renal function was unique in diabetes.

Methodology and technology for peripheral and central blood pressure and blood pressure variability measurement: current status and future directions - Position statement of the European Society of Hypertension Working Group on blood pressure monitoring and cardiovascular variability

Office blood pressure measurement has been the basis for hypertension evaluation for almost a century. However, the evaluation of blood pressure out of the office using ambulatory or self-home monitoring is now strongly recommended for the accurate diagnosis in many, if not all, cases with suspected hypertension. Moreover, there is evidence that the variability of blood pressure might offer prognostic information that is independent of the average blood pressure level. Recently, advancement in technology has provided noninvasive evaluation of central (aortic) blood pressure, which might have attributes that are additive to the conventional brachial blood pressure measurement. This position statement, developed by international experts, deals with key research and practical issues in regard to peripheral blood pressure measurement (office, home, and ambulatory), blood pressure variability, and central blood pressure measurement. The objective is to present current achievements, identify gaps in knowledge and issues concerning clinical application, and present relevant research questions and directions to investigators and manufacturers for future research and development (primary goal).

Blood pressure variability: assessment, predictive value, and potential as a therapeutic target

A large body of evidence has consistently supported the relationship between blood pressure (BP) levels and the risk of cardiovascular complications. In recent years, several independent studies have also indicated that this risk may not only depend on the magnitude of the blood pressure elevation per se but also on the presence of other associated conditions such as increased blood pressure variability. This concept has been supported by a series of reports, most of which post hoc analyses of clinical trials in hypertension, showing that increasing values of BP variability (BPV) (either in the short term, in the midterm, or in the long term) may predict development, progression, and severity of cardiac, vascular, and renal organ damage, as well as cardiovascular events and mortality. Remarkably, studies conducted in populations at high cardiovascular risk have shown increasing values of BPV in the individual subjects (so-called intra- or within-individual BPV) to be strong predictors of cardiovascular morbidity and mortality, even to a larger extent than average BP values. However, in subjects at low to moderate cardiovascular risk, the contribution of BPV to cardiovascular risk prediction over and beyond average BP values has been shown to be only moderate. The aim of this paper is to critically review the evidence addressing the prognostic relevance of different components of BPV addressing a yet open question, i.e., whether routine assessment of BPV in clinical practice should be regarded as an additional target of antihypertensive treatment to improve cardiovascular protection.

Correlation of Central Blood Pressure to Hypertensive Target Organ Damages During Antihypertensive Treatment: The J-TOP Study

BACKGROUND

Some previous studies have shown that central blood pressure (BP) is more closely related to cardiovascular risks than brachial BP. This study compared the correlations between asymptomatic organ damages and each of central BP, brachial clinic BP, and home BP during antihypertensive treatment.

METHODS

In the Japan Morning Surge-Target Organ Protection (J-TOP) study, which compared bedtime or awakening dosing of candesartan (+diuretics as needed) among subjects with home systolic BP (SBP) higher than 135 mm Hg, we evaluated 180 hypertensive patients who successfully underwent pulse wave analysis by HEM-9000AI and measured their urinary albumin/creatinine ratio (UACR) and left ventricular mass index (LVMI) (n = 144) at baseline and after 6 months of treatment.

RESULTS

During antihypertensive treatment, significant reductions were found in central SBP, UACR, and LVMI (all P < 0.001). Multiple regression analyses showed that the decrease in central SBP was associated with those of log-transformed UACR (β = 0.24, P < 0.01) and LVMI (β = 0.23, P = 0.04), independently of the decrease in both clinic and home SBP. The goodness-of-fit of the association between the reduction in SBP and the UACR (P < 0.01) or LVMI (P = 0.04) was improved by adding central SBP to the SBP measurement.

CONCLUSION

These findings suggest that the change in central BP could be an important therapeutic target during antihypertensive treatment, in addition to peripheral clinic and home BP.

Blood pressure variability assessed by home measurements: a systematic review

Accumulating evidence suggests that day-by-day blood pressure (BP) variability assessed using self-measurements by patients at home (HBPV) provides useful information beyond that of average home BP. This systematic review summarizes the current evidence on day-by-day HBPV. A systematic literature search (PubMed) revealed 22 eligible articles. Independent prognostic value of day-by-day HBPV for cardiovascular events and total mortality was demonstrated in two outcome studies, whereas novel indices of variability had minimal or no independent prognostic ability. Although findings are not consistent among the studies, the evidence suggests that HBPV has an independent role in the progression of preclinical cardiac, arterial and renal damage and is affected by age, gender, average BP and heart rate level, antihypertensive treatment, antihypertensive drug class and other factors. However, there is large diversity among the available studies in the home BP monitoring protocols, the indices used to quantify HBPV and the end points selected for evaluation. Overall, these preliminary data largely based on heterogeneous studies indicate an important and independent role of day-by-day HBPV in the pathogenesis of hypertension-induced cardiovascular damage. Yet, fundamental questions remain unanswered, including the optimal variability index, the optimal home monitoring schedule required, the threshold that defines increased HBPV and the impact of treatment-induced variability change on organ damage and cardiovascular events. Until these questions are adequately addressed in future studies, HBPV should largely remain a research issue with limited practical value for individual patients.