Blood pressure variability and cardiovascular prognosis: implications for clinical practice

Association between baseline blood pressure variability and left heart function following short-term extreme cold exposure

Extreme cold exposure has been widely considered as a cardiac stress and may result in cardiac function decompensation. This study was to examine the risk factors that contribute to changes in cardiovascular indicators of cardiac function following extreme cold exposure and to provide valuable insights into the preservation of cardiac function and the cardiac adaptation that occur in real-world cold environment. Seventy subjects were exposed to cold outside (Mohe, mean temperature -17 to -34°C) for one day, and were monitored by a 24-h ambulatory blood pressure device and underwent echocardiography examination before and after extreme cold exposure. After exposure to extreme cold, 41 subjects exhibited an increase in ejection fraction (EF), while 29 subjects experienced a decrease. Subjects with elevated EF had lower baseline coefficients of variation (CV) in blood pressure compared to those in the EF decrease group. Additionally, the average real variability (ARV) of blood pressure was also significantly lower in the EF increase group. Multivariate regression analysis indicated that both baseline CV and ARV of blood pressure were independent risk factors for EF decrease, and both indicators proved effective for prognostic evaluation. Correlation analysis revealed a correlation between baseline blood pressure CV and ARV, as well as EF variation after exposure to extreme cold environment. Our research clearly indicated that baseline cardiovascular indicators were closely associated with the changes in EF after extreme cold exposure. Furthermore, baseline blood pressure variability could effectively predict alterations in left cardiac functions when individuals were exposed to extreme cold environment.

Evaluation of blood pressure variation in recovered COVID-19 patients at one-year follow-up: a retrospective cohort study

BACKGROUND

Coronavirus disease 2019 (COVID-19) has various sequelae, one of which might be hypertension. We aimed to evaluate COVID-19's impact on blood pressure (BP) in non-hospitalized patients at one-year follow-up.

METHOD

A total of 7,950 consecutive COVID-19 patients regularly visiting our cardiology clinic were retrospectively screened. Patients' electronic medical records including demographics, comorbidities, vital signs, treatments, and outcomes, were reviewed by two physicians. Individuals with at least one BP measurement in the three months preceding COVID-19 and one measurement in 12 months or more following recovery were included. BP levels before and after COVID-19 were compared using the paired t-test.

RESULTS

5,355 confirmed COVID-19 patients (mean age 55.51 ± 15.38 years) were included. Hypertension (56.9%) and diabetes mellitus (34%) were the predominant comorbidities, and 44.3% had prior major adverse cardiovascular events. Both systolic (126.90 ± 20.91 vs. 139.99 ± 23.94 mmHg, P < 0.001) and diastolic BP (80.54 ± 13.94 vs. 86.49 ± 14.40 mmHg, P < 0.001) were significantly higher post-COVID-19 vs. pre-COVID-19. Notably, 456 (14%) hypertensive patients experienced exacerbated hypertension, while 408 (17%) patients developed new-onset hypertension, overall 864 (16%) of patients had exacerbation or new hypertension. Linear regression analysis revealed that advanced age, smoking, previous cardiovascular events, hypertension, and diabetes mellitus predict increased BP following COVID-19 (P < 0.001).

CONCLUSION

COVID-19 raised systolic and diastolic BP in the long term in non-hospitalized patients, with over one-sixth developing new-onset or exacerbated hypertension. All patients should be evaluated regarding BP, following COVID-19 recovery, particularly those with the mentioned predictive factors. (clinicaltrial.gov: NCT05798208).

Feasibility, credence, and usefulness of out-of-office cuffless blood pressure monitoring using smartwatch: a population survey

BACKGROUND

Cuffless blood pressure (BP) measurement, enabled by recent advances in wearable devices, allows for BP monitoring in daily life. This study aims to evaluate the feasibility, cresdence, and usefulness of cuffless BP monitoring through a population survey.

METHODS

During the "Daily BP Measurement with Your Galaxy Watch" campaign held by the Korean Society of Hypertension, participants were asked to share their experiences with cuffless BP measurement using a smartwatch application through an online survey. The questionnaire included questions about age, underlying medical conditions, smartwatch utilization, experience with BP calibration, the reliability of BP values measured by a smartwatch, and willingness to use the BP monitoring function in the future.

RESULTS

A total of 1071 participants responded to the survey. The largest age group (decile) was 50-59 years old (33.3%), followed by 40-49 years old (29.9%). Although nearly half of the participants (47.5%) had no chronic diseases, 40.1% reported having hypertension. BP monitoring was the most frequently utilized smartwatch function (95.8%), followed by heart rate measurement (87.1%). 31.8% of participants reported that BP values measured by the smartphone application were "very accurate and helpful," while 63.5% rated them as "slightly lower (44.4%)" or "higher (19.1%)" compared to the standard home BP monitoring device. 93% of the participants reported utilizing the BP monitoring function at least once a week. Regarding the BP calibration process, most participants (93.9%) calibrated the BP measurement application themselves, and 50.8% rated the difficulty level as "very easy."

CONCLUSION

Cuffless BP measurement using a smartwatch application was feasible in the general population, including the self-calibration process. However, the satisfaction level in terms of accuracy is still modest, indicating a need for further development.

Feasibility and measurement stability of smartwatch-based cuffless blood pressure monitoring: A real-world prospective observational study

Cuffless wearable devices are currently being developed for long-term monitoring of blood pressure (BP) in patients with hypertension and in apparently healthy people. This study evaluated the feasibility and measurement stability of smartwatch-based cuffless BP monitoring in real-world conditions. Users of the first smartwatch-based cuffless BP monitor approved in Korea (Samsung Galaxy Watch) were invited to upload their data from using the device for 4 weeks post calibration. A total of 760 participants (mean age 43.7 ± 11.9, 80.3% men) provided 35,797 BP readings (average monitoring 22 ± 4 days [SD]; average readings 47 ± 42 per participant [median 36]). Each participant obtained 1.5 ± 1.3 readings/day and 19.7% of the participants obtained measurements every day. BP showed considerable variability, mainly depending on the day and time of the measurement. There was a trend towards higher BP levels on Mondays than on other days of the week and on workdays than in weekends. BP readings taken between 00:00 and 04:00 tended to be the lowest, whereas those between 12:00 and 16:00 the highest. The average pre-post calibration error for systolic BP (difference in 7-day BP before and after calibration), was 6.8 ± 5.6 mmHg, and was increased with higher systolic BP levels before calibration. Smartwatch-based cuffless BP monitoring is feasible for out-of-office monitoring in the real-world setting. The stability of BP measurement post calibration and the standardization and optimal time interval for recalibration need further investigation.

Is remote blood pressure monitoring and management a better approach for patients with hypertension? A narrative review

Hypertension is a global public health problem which affects the physical and mental health of individuals. The management of hypertension is a long-term process that requires the cooperation of both doctors and patients, and the blood pressure variability is closely related to the clinical prognosis. In recent years, the development of telemedicine has promoted better blood pressure monitoring and management for patients, as well as better medical intervention and health education for patients by medical staff. This article provides a review of remote blood pressure monitoring and management.

Blood Pressure Fluctuation During Hospitalization and Clinical Outcomes Within 3 Months After Ischemic Stroke

BACKGROUND

Increased blood pressure (BP) variability is positively associated with the risks of cerebral small-vessel disease, cardiovascular events and death. However, no large clinical trials have been published to demonstrate the effect of BP fluctuations during hospitalization on clinical outcomes after ischemic stroke.

METHODS

A total of 3972 patients with acute ischemic stroke from 26 participating hospitals were included in this study, and BP fluctuations were calculated using BP data collected during the hospitalization. The primary outcome was composite outcome of death or major disability (modified Rankin Scale score ≥3) within 3 months and secondary outcomes included death, vascular events, and composite outcomes (death or vascular events).

RESULTS

Compared with the lowest quartile of systolic BP fluctuations, the adjusted odds ratio associated with the highest quartile was 1.33 ([95% CI, 1.05-1.68]; P_trend=0.011) for primary outcome; the adjusted hazard ratios were 2.89 ([95% CI, 1.58-5.32]; P_trend<0.001) for death, 1.48 ([95% CI, 0.83-2.65]; P_trend=0.071) for vascular events, and 2.06 ([95% CI, 1.32-3.23]; P_trend<0.001) for composite outcome. Similar results were found for diastolic BP. Multivariable adjusted restricted cubic spline analysis showed a linear relationship between systolic BP fluctuations and the primary outcome (P for linearity=0.0009).

CONCLUSIONS

Larger BP fluctuations during hospitalization were associated with an increased risk of adverse outcomes at 3 months after ischemic stroke onset, independent of mean BP. These findings suggested that BP fluctuation should be a risk factor of adverse outcomes after ischemic stroke, which provided a new insight for BP management strategy.

High visit-to-visit blood pressure variability predicts global cognitive decline: The Multi-Ethnic Study of Atherosclerosis

Background

Research of hypertension-related risk factors for Alzheimer's disease has typically focused on blood pressure (BP) levels, despite evidence that high blood pressure variability (BPV) over time may predict poorer cardiovascular, neuropathological, and neurocognitive outcomes. We evaluated associations between BPV and cognitive function in the Multi-Ethnic Study of Atherosclerosis (MESA).

Methods

Multivariable linear and logistic regression analyses of BP data across six examinations were used to determine associations that BPV (average real variability [ARV], variability independent of the mean [VIM]) and group-based latent BP trajectories have with cognitive function, decline, and impairment, measured by the Cognitive Abilities Screening Instrument (CASI), Digit Symbol Coding (DSC), and Digit Span tests.

Results

Participants (N = 1314; mean baseline age = 57) were 50% female, and 48% White. Higher systolic (β = -0.06, 95% confidence interval [CI]: -0.12, -0.0001) and diastolic (β = -0.08, 95% CI: -0.14, -0.02) ARV predicted increased global cognitive decline after covariate adjustment. Stronger relationships between BPV and global cognition were in older, White and Black participants, apolipoprotein E (APOE) ε4 non-carriers, male participants, and non-antihypertensive medication users.

Conclusion

Results suggest that higher systolic and diastolic BPV is an independent risk factor for cognitive dysfunction and decline in this multi-ethnic cohort. This relationship differs across demographic and clinical characteristics.

The Effect of Blood Pressure Variability on Coronary Atherosclerosis Plaques

Hypertension is one of the most important risk factors for coronary heart disease (CHD). The regulation of blood pressure plays a significant role in the development and prognosis of CHD. Blood pressure variability (BPV) refers to the degree of fluctuation of blood pressure over a period of time and is an important indicator of blood pressure stability. Blood pressure fluctuations are complex physiological phenomena, being affected by physiological and pharmacological effects and regulated by behavioral, environmental, hydrodynamic, and neural factors. According to the different time periods for measuring BPV, it can be divided into very short-term, short-term, mid-term, and long-term. Multiple cardiovascular disease animal models and clinical experiments have consistently indicated that abnormal BPV is closely related to coronary events and is a risk factor for CHD independently of average blood pressure. Thrombosis secondary to plaque rupture (PR) or plaque erosion can cause varying blood flow impairment, which is the main pathological basis of CHD. Plaque morphology and composition can influence the clinical outcome, treatment, and prognosis of patients with CHD. Research has shown that PR is more easily induced by hypertension. After adjusting for the traditional factors associated with plaque development, in recent years, some new discoveries have been made on the influence of abnormal BPV on the morphology and composition of coronary plaques and related mechanisms, including inflammation and hemodynamics. This article reviews the impact of BPV on coronary plaques and their related mechanisms, with a view to prevent the occurrence and development of CHD by controlling BPV and to provide new prevention and treatment strategies for the clinical treatment of abnormal blood pressure.

Clinical impact of blood pressure variability in patients with COVID-19 and hypertension

OBJECTIVE

This study aimed to investigate the relationship between blood pressure variability (BPV) and clinical outcomes in patients with coronavirus disease 2019 (COVID-19) and hypertension.

METHODS

A total of 136 patients hospitalized with COVID-19 were enrolled in this study. Patients were grouped according to the presence of hypertension and BPV. Mean arterial pressure (MAP) measured at 8 a.m. and 8 p.m. was analyzed, and BPV was calculated as the coefficient of variation of MAP (MAPCV). High BPV was defined as MAPCV values above the median. We compared the age, level of C-reactive protein (CRP), creatine kinase-MB (CK-MB), N-terminal pro-B type natriuretic peptide (NT-proBNP), creatinine and in-hospital mortality and investigated the relationship among the groups.

RESULTS

COVID-19 patients with hypertension were older (70 ± 12 vs. 53 ± 17 years; P < 0.001), had higher levels of CRP (9.4 ± 9.2 vs. 5.3 ± 8.2 mg/dL; P = 0.009), MAPCV (11.4 ± 4.8 vs. 8.9 ± 3.2; P = 0.002), and higher in-hospital mortality (19.6% vs. 5.9%; P = 0.013) than those without hypertension. There was a proportional relationship between BPV and age, levels of CRP, CK-MB, NT-proBNP, creatinine and in-hospital mortality (all, P < 0.05). In Cox regression analysis, advanced age [≥80 years, hazard ratio (HR) 10.4, 95% confidence interval (CI) 2.264-47.772, P = 0.003] and higher MAPCV (HR 1.617, 95% CI, 1.281-2.040, P < 0.001) were significantly associated with in-hospital mortality.

CONCLUSION

High BPV in COVID-19 patients with hypertension is significantly associated with in-hospital mortality. Advanced age and systemic inflammation are proportional to high BPV. Additional attention is needed for COVID-19 patients with hypertension and high BPV.

The Effects of Altitude-related Hypoxia Exposure on the Multiscale Dynamics of Blood Pressure Fluctuation During Sleep: The Observation from a Pilot Study

PURPOSE

The purpose exposure to hypoxia in high altitudes severely impairs the sleep quality and the related cardiovascular regulation, including the blood pressure (BP) regulation. BP regulation depends upon the continuous interaction of components over multiple temporal scales. As such, the dynamics of BP fluctuation are complex, and BP complexity has been linked to several pathological events. However, the effects of the exposure to hypoxia on BP complexity during sleep remain unknown.

METHODS

Twenty-five younger men naïve to high-altitude sleep (apnea severity as assessed by hypoxia apnea index (AHI): normal=8; moderate=9; severe=8) completed one nocturnal sleep under each of the three altitudes: 0 (ie, baseline), 2000, and 4000 m. The sleep characteristics and oxygen saturation (ie, SpO2) were assessed using polysomnography (PSG). The beat-to-beat BP fluctuation was recorded using a finger-blood-pressure sensor. Multiscale entropy (MSE) was used to characterize the complexity of systolic (SBP) and diastolic (DBP) BP fluctuations, and lower MSE reflected lower complexity.

RESULTS

Compared to 0-m condition, SBP (p=0.0003) and DBP (F=12.1, p=0.0002) complexity, SpO2 (p<0.0001) and REM ratio (p<0.0090) were decreased, AHI was increased (p=0.0004) in 2000-m and even more in 4000-m conditions. In addition, lower BP complexity was associated with greater AHI (r=-0.66~0.52, p=0.0010), lower SpO2 (r=0.48~0.51, p=0.0100~0.0200) and lower REM ratio (r=0.48~0.52, p=0.0200). Participants with greater percent reduction in BP complexity between altitudes had greater percent reduction in REM ratio and SpO2 (r=0.38~0.45, p=0.0090~0.0200), after adjustment for age, BMI, baseline apnea and altitude.

CONCLUSION

These results suggested that the characterization of BP complexity may provide novel insights into the underlying mechanisms through which the exposure to hypoxia affects cardiovascular health during sleep, as well as sleep quality. This BP complexity may serve as a novel marker to help the management of cardiovascular health and sleep quality in high-altitude living.

Impact of dietary intake of sodium and potassium on short-term blood pressure variability

BACKGROUND

Dietary Approaches to Stop Hypertension (DASH)-Sodium trial showed that dietary sodium and potassium affect blood pressure (BP). We aimed to investigate whether dietary sodium and potassium affect short-term BP variability (BPV) in addition to BP.

METHODS

A total of 343 participants from the DASH-Sodium trial (age 48.4 ± 9.7, 42.5% men) and 323 individuals from the Jackson Heart Study (JHS) (age 56.7 ± 11.2, 30.7% men) with satisfactory ambulatory BP monitoring records and 24-h urine collection were included. Average real variability (ARV) was calculated as a measure of short-term BPV.

RESULTS

By estimating dietary intake from urinary excretion, we observed that higher urinary sodium-to-potassium ratio was significantly associated with higher diastolic ARV in both studies. Among the DASH-Sodium trial, potassium-rich DASH diet alone had insignificant effect on both systolic (-0.1 ± 1.7 mmHg, P = 0.343) or diastolic ARV (-0.2 ± 1.5 mmHg, P = 0.164), whereas combined DASH diet and low sodium intake significantly reduced both systolic (8.5 ± 1.6 vs. 8.9 ± 1.7 mmHg, P = 0.032) and diastolic ARV (7.5 ± 1.5 vs. 7.8 ± 1.6 mmHg, P = 0.025) as compared with control diet and high sodium intake. As the reduction of systolic ARV was majorly derived from the change of mean SBP, diastolic ARV was significantly determined by urinary sodium-to-potassium ratio (β coefficient ± standard error: 0.012 ± 0.004; P = 0.006) after adjusting for age, sex, smoking, mean DBP, BMI, and race.

CONCLUSION

Dietary sodium and potassium can jointly modulate short-term BPV in addition to BP. Combined DASH diet and low sodium intake may reduce systolic and diastolic ARV via different mechanisms.

Blood Pressure Variability and Age-related Blood Pressure Patterns in Systemic Lupus Erythematosus

OBJECTIVE

Despite the high prevalence of cardiovascular (CV) disease among patients with systemic lupus erythematosus (SLE), the relationship between age, blood pressure (BP), and BP variability (BPV) is not well understood. We studied visit-to-visit BPV, its relationship to age, clinical, and demographic characteristics, and its potential role as a CV risk factor in patients with SLE.

METHODS

We analyzed systolic (SBP) and diastolic BP (DBP) measures in our cohort using mixed-effects regression models. From these models, we then obtained estimates of the mean BP, the visit-to-visit SD, and the between-person SD. The estimated means were compared to the general population using data from the National Health Statistics Reports from 2001 to 2008. In addition, we examined the relationship between BP (means, variances), patient demographic and clinical characteristics, and subsequent CV events.

RESULTS

The mean SBP in SLE increased with age and was significantly higher in younger patients compared to the general population. BPV in SLE was elevated across all ages. BPV was significantly higher in African Americans, in patients with traditional CV risk factors, those with high disease activity, and in patients taking prednisone. Hydroxychloroquine was associated with significantly lower BPV. Within-person variability in DBP of ≥ 9 mmHg was highly associated with CV events in a multivariate analysis.

CONCLUSION

Age-related BP patterns in SLE differ from the general population. Increased visit-to-visit BPV is affected by many disease-specific and traditional CV factors. Increased DBP variability is highly associated with CV events in SLE.

Blood Pressure Variability and Therapeutic Implications in Hypertension and Cardiovascular Diseases

Blood pressure (BP) is characterized by continuous dynamic and spontaneous oscillations occurring over lifetime and defining the so-called blood pressure variability (BPV). BPV has been associated with target organ damage, cardiovascular (CV) risk and death, suggesting the use of BPV as a new target in hypertension management in addition to mean BP values lowering. The purpose of the review is to focus on the therapeutic implications of BPV and summarize the effects of different drug classes on various types of BPV. Despite most first-line antihypertensive medications contribute to reduce both short and long term BPV, calcium channel blockers (CCBs) as monotherapy or fixed-combination therapy appear to be the most effective on BPV control. Further randomized interventional trials are needed to investigate which drug combinations are most appropriate according to patient CV risk stratification, in order to improve their CV outcomes.

Cardiovascular Risk Factors and Markers

Cardiovascular risk is assessed for the prediction and appropriate management of patients using collections of identified risk markers obtained from clinical questionnaire information, concentrations of certain blood molecules (e.g., N-terminal proB-type natriuretic peptide fragment and soluble receptors of tumor-necrosis factor-α and interleukin-2), imaging data using various modalities, and electrocardiographic variables, in addition to traditional risk factors.