Project description:Hemodynamic stability during surgery seems to account for positive postoperative outcomes in patients. However, little is known about the impact of intraoperative blood pressure variability (IBPV) on the postoperative complications. The aim was to investigate whether IBPV is associated with the development of postoperative complications and what is the nature of this association. We conducted a systematic search in PubMed, Medical Subject Headings, Embase, Web of Science, SCOPUS, clinicaltrials.gov, and Cochrane Library on the 8th of April, 2021. We included studies that only focused on adults who underwent primarily elective, non-cardiac surgery in which intraoperative blood pressure variation was measured and analyzed in regard to postoperative, non-surgical complications. We identified 11 papers. The studies varied in terms of applied definitions of blood pressure variation, of which standard deviation and average real variability were the most commonly applied definitions. Among the studies, the most consistent analyzed outcome was a 30-day mortality. The studies presented highly heterogeneous results, even after taking into account only the studies of best quality. Both higher and lower IBPV were reported to be associated for postoperative complications. Based on a limited number of studies, IBPV does not seem to be a reliable indicator in predicting postoperative complications. Existing premises suggest that either higher or lower IBPV could contribute to postoperative complications. Taking into account the heterogeneity and quality of the studies, the conclusions may not be definitive.
Project description:Blood pressure variability (BPV) and heart rate variability (HRV) have been associated with Alzheimer's Disease and Related Dementias (ADRD) in rigorously controlled studies. However, the extent to which BPV and HRV may offer predictive information in real-world, routine clinical care is unclear. In a retrospective cohort study of 48,204 adults (age 54.9 ± 17.5 years, 60% female) receiving continuous care at a single center, we derived BPV and HRV from routinely collected clinical data. We use multivariable Cox models to evaluate the association of BPV and HRV, separately and in combination, with incident ADRD. Over a median 3 [2.4, 3.0] years, there were 443 cases of new-onset ADRD. We found that clinically derived measures of BPV, but not HRV, were consistently associated with incident ADRD. In combined analyses, only patients in both the highest quartile of BPV and lowest quartile of HRV had increased ADRD risk (HR 2.34, 95% CI 1.44-3.81). These results indicate that clinically derived BPV, rather than HRV, offers a consistent and readily available metric for ADRD risk assessment in a real-world patient care setting. Thus, implementation of BPV as a widely accessible tool could allow clinical providers to efficiently identify patients most likely to benefit from comprehensive ADRD screening.
Project description:BackgroundIndividual-level blood pressure (BP) variability, independent of mean BP levels, has been associated with increased risk for cardiovascular events in cohort studies and clinical trials using standardized BP measurements. The extent to which BP variability relates to cardiovascular risk in the real-world clinical practice setting is unclear. We sought to determine if BP variability in clinical practice is associated with adverse cardiovascular outcomes using clinically generated data from the electronic health record (EHR).MethodsWe identified 42,482 patients followed continuously at a single academic medical center in Southern California between 2013 and 2019 and calculated their systolic and diastolic BP variability independent of the mean (VIM) over the first 3 years of the study period. We then performed multivariable Cox proportional hazards regression to examine the association between VIM and both composite and individual outcomes of interest (incident myocardial infarction, heart failure, stroke, and death).FindingsBoth systolic (HR, 95% CI 1.22, 1.17-1.28) and diastolic VIM (1.24, 1.19-1.30) were positively associated with the composite outcome, as well as all individual outcome measures. These findings were robust to stratification by age, sex and clinical comorbidities. In sensitivity analyses using a time-shifted follow-up period, VIM remained significantly associated with the composite outcome for both systolic (1.15, 1.11-1.20) and diastolic (1.18, 1.13-1.22) values.InterpretationVIM derived from clinically generated data remains associated with adverse cardiovascular outcomes and represents a risk marker beyond mean BP, including in important demographic and clinical subgroups. The demonstrated prognostic ability of VIM derived from non-standardized BP readings indicates the utility of this measure for risk stratification in a real-world practice setting, although residual confounding from unmeasured variables cannot be excluded.FundingThis study was funded in part by National Institutes of Health grants R01-HL134168, R01-HL131532, R01-HL143227, R01-HL142983, U54-AG065141; R01-HL153382, K23-HL136853, K23-HL153888, and K99-HL157421; China Scholarship Council grant 201806260086; Academy of Finland (Grant no: 321351); Emil Aaltonen Foundation; Finnish Foundation for Cardiovascular Research.
Project description:BackgroundBlood pressure variability (BPV) describes visit-to-visit blood pressure (BP) changes independent of hypertension. Preoperative BPV and intraoperative BPV are associated with increased postoperative outcomes. We investigated the impact of both preoperative BPV and intraoperative BPV on elective surgical outcomes, specifically whether preoperative BPV and intraoperative BPV were independent risk factors for surgical complications.Materials and methodsWe investigated 600 patients undergoing elective surgery lasting more than two h and who had ≥8 outpatient BP recordings over three preoperative years. Age, sex, ethnicity, BMI, current medical problems, and medications at time of surgery were recorded. BPV was calculated as the standard deviation (SD) of systolic or diastolic BP for the 369 valid patients. Average BPV were compared between adverse outcomes of readmission, wound infection, acute kidney injury, death, myocardial infarction, and cerebral vascular accident.ResultsThree-hundred-sixty-nine (52.6% male, 47.4% female, 98.1% non-Hispanic) patients (mean age 62.5) were included in the study. Preoperative systolic (P = 0.043) and diastolic (P = 0.009) BPV were higher for patients with the combined endpoint of all adverse events. Preoperative systolic BPV was correlated with intraoperative BPV (P = 0.010). Both systolic and diastolic preoperative BPV was found to be independent from intraoperative BPV. Otolaryngology procedures were associated with less adverse outcomes (P = 0.034), whil antimicrobials (P = 0.022), autonomic drugs (P < 0.001), or respiratory drugs (P = 0.032) was associated with an increased likelihood of adverse outcome.ConclusionPreoperative DBPV is associated with increased risk of readmission, wound infection and the combined endpoint of all adverse events. Intraoperative systolic blood pressure variability (SPBV) is associated with increased risk of acute kidney injury and the combined endpoint of all adverse events. Preoperative DBPV and intraoperative SBPV are independent risk factors for ninety-d postoperative outcomes. BPV should be considered in individualized risk assessment when assessing patient eligibility for elective procedures.
Project description:Background and objectivesShort-term BP variability (derived from 24-hour ambulatory BP monitoring) and long-term BP variability (from clinic visit to clinic visit) are directly related to risk for cardiovascular events, but these relationships have been scarcely investigated in patients with CKD, and their prognostic value in this population is unknown.Design, setting, participants, & measurementsIn a cohort of 402 patients with CKD, we assessed associations of short- and long-term systolic BP variability with a composite end point of death or cardiovascular event. Variability was defined as the standard deviation of observed BP measurements. We further tested the prognostic value of these parameters for risk discrimination and reclassification.ResultsMean ± SD short-term systolic BP variability was 12.6±3.3 mm Hg, and mean ± SD long-term systolic BP variability was 12.7±5.1 mm Hg. For short-term BP variability, 125 participants experienced the composite end point over a median follow-up of 4.8 years (interquartile range, 2.3-8.6 years). For long-term BP variability, 110 participants experienced the composite end point over a median follow-up of 3.2 years (interquartile range, 1.0-7.5 years). In adjusted analyses, long-term BP variability was significantly associated with the composite end point (hazard ratio, 1.24; 95% confidence interval, 1.01 to 1.51 per 5-mm Hg higher SD of office systolic BP), but short-term systolic BP variability was not (hazard ratio, 0.92; 95% confidence interval, 0.68 to 1.25 per 5-mm Hg higher SD of 24-hour ambulatory systolic BP). Neither estimate of BP variability improved risk discrimination or reclassification compared with a simple risk prediction model.ConclusionsIn patients with CKD, long-term but not short-term systolic BP variability is related to the risk of death and cardiovascular events. However, BP variability has a limited role for prediction in CKD.
Project description:BackgroundVisit-to-visit blood pressure (BP) variability associates with an increased risk of cardiovascular events. We investigated the role of seasonal BP modifications on the magnitude of BP variability and its impact on cardiovascular risk.MethodsIn 25 390 patients included in the ONTARGET and TRANSCEND trials, the on-treatment systolic (S) BP values obtained by five visits during the first two years of the trials were grouped according to the month in which they were obtained. SBP differences between winter and summer months were calculated for BP variability quintiles (Qs), as quantified by the coefficient of variation (CV) of on-treatment mean SBP from the five visits. The relationship of BP variability with the risk of cardiovascular events and mortality was assessed by the Cox regression model.ResultsSBP was approximately 4 mmHg lower in summer than in winter regardless of confounders. Winter/summer SBP differences contributed significantly to each SBP-CV quintile. Increase of SBP-CV from Q1 to Q5 was associated with a progressive increase in the adjusted hazard ratio (HR) of the primary endpoint of the trials, i.e. morbid and fatal cardiovascular events. This association was even stronger after removal of the effect of seasonality from the calculation of SBP-CV. A similar trend was observed for secondary endpoints.ConclusionsWinter/summer SBP differences significantly contribute to visit-to-visit BP variability. However, this contribution does not participate in the adverse prognostic significance of visit-to-visit BP variations, which seems to be more evident after removal of the BP effects of seasonality from visit-to-visit BP variations.
Project description:Studies of visit-to-visit office blood pressure (BP) variability (OBPV) as a predictor of cardiovascular events and death in high-risk patients treated to lower BP targets are lacking. We conducted a post hoc analysis of SPRINT (Systolic Blood Pressure Intervention Trial), a well-characterized cohort of participants randomized to intensive (<120 mm Hg) or standard (<140 mm Hg) systolic BP targets. We defined OBPV as the coefficient of variation of the systolic BP using measurements taken during the 3-,6-, 9-, and 12-month study visits. In our cohort of 7879 participants, older age, female sex, black race, current smoking, chronic kidney disease, and coronary disease were independent determinants of higher OBPV. Use of thiazide-type diuretics or dihydropyridine calcium channel blockers was associated with lower OBPV whereas angiotensin-converting enzyme inhibitors or angiotensin receptor blocker use was associated with higher OBPV. There was no difference in OBPV in participants randomized to standard or intensive treatment groups. We found that OBPV had no significant associations with the composite end point of fatal and nonfatal cardiovascular events (n=324 primary end points; adjusted hazard ratio, 1.20; 95% confidence interval, 0.85-1.69, highest versus lowest quintile) nor with heart failure or stroke. The highest quintile of OBPV (versus lowest) was associated with all-cause mortality (adjusted hazard ratio, 1.92; confidence interval, 1.22-3.03) although the association of OBPV overall with all-cause mortality was marginal (P=0.07). Our results suggest that clinicians should continue to focus on office BP control rather than on OBPV unless definitive benefits of reducing OBPV are shown in prospective trials.Clinical trial registrationURL: http://www.clinicaltrials.gov. Unique identifier: NCT01206062.
Project description:Visit-to-visit blood pressure (BP) variability has received considerable attention recently. The objective of our study is to define a variability measure that is independent of change over time and determine the association between longitudinal summary measures of BP measurements and mortality risk. Data for the study came from a prospective cohort of 2906 adults, aged ≥60 years, in an urban primary care system with ≤15 years of follow-up. Dates of death for deceased participants were retrieved from the National Death Index. Systolic and diastolic BP measurements from outpatient clinic visits were extracted from the Regenstrief Medical Record System. For each patient, the intercept, regression slope, and root mean square error for visit-to-visit variability were derived using linear regression models and used as independent variables in Cox proportional hazards models for both all-cause mortality and mortality attributable to coronary heart disease or stroke. Rate of change was associated with mortality risk in a U-shaped relationship and that participants with little or no change in BP had the lowest mortality risk. BP variability was not an independent predictor of mortality risk. By separating change over time from visit-to-visit variability in studies with relatively long follow-up, we demonstrated in this elderly primary care patient population that BP changes over time, not variability, were associated with greater mortality risk. Future research is needed to confirm our findings in other populations.
Project description:Visit-to-visit blood pressure variability (VTV-BPV) is an independent risk factor for cardiovascular events and death in the general population. We sought to determine the association of VTV-BPV with outcomes in patients on hemodialysis, using data from a National Institutes of Health-sponsored randomized trial (the HEMO study). We used the coefficient of variation (CV) and the average real variability in systolic blood pressure (SBP) as metrics of VTV-BPV. In all, 1844 out of 1846 randomized subjects had at least three visits with SBP measurements and were included in the analysis. Median follow-up was 2.5 years (interquartile range 1.3-4.3 years), during which time there were 869 deaths from any cause and 408 (adjudicated) cardiovascular deaths. The mean pre-dialysis SBP CV was 9.9 ± 4.6%. In unadjusted models, we found a 31% higher risk of death from any cause per 10% increase in VTV-BPV. This association was attenuated after multivariable adjustment but remained statistically significant. Similarly, we found a 28% higher risk of cardiovascular death per 10% increase in VTV-BPV, which was attenuated and no longer statistically significant in fully adjusted models. The associations among VTV-BPV, death and cardiovascular death were modified by baseline SBP. In a diverse, well-dialyzed cohort of patients on maintenance hemodialysis, VTV-BPV, assessed using metrics of variability in pre-dialysis SBP, was associated with a higher risk of all-cause mortality and a trend toward higher risk of cardiovascular mortality, particularly in patients with a lower baseline SBP.
Project description:SPRINT (Systolic Blood Pressure Intervention Trial) highlighted the benefits of intensive targeted antihypertensive therapy but resulted in higher rates of treatment-related adverse events. Blood pressure (BP) variability has emerged as a significant predictor of outcomes over and above levels of BP. Using the SPRINT data set, we aimed to determine the relationship of BP variability with cardiovascular outcomes and side effects of antihypertensive therapy. The analyses included all participants randomized in SPRINT who reached the target systolic BP (SBP) for their respective groups (intensive < 120 mm Hg; standard < 140 mm Hg). Coefficients of variation (CV) for SBP, diastolic BP (DBP), and PP for each patient characterized variability. Student t test was used to compare treatment arms for each CV metric. Cox proportional hazards regression was used to identify independent predictors of the SPRINT primary outcome and adverse events. P < .15 on univariate analysis was required to enter the model and P < .05 to remain in it. A total of 8884 patients (4561 standard group; 4323 intensive group) met inclusion criteria. DBP CV differed between the groups (9.12 ± 3.20 standard group; 9.47 ± 3.49 intensive group [P < .0001]). DBP CV predicted a greater hazard for the primary outcome (hazard ratio [HR], 1.14) in the overall model as well as separate analyses by treatment arms (standard group HR, 1.15; intensive group HR, 1.19), each P < .0001. DBP CV also independently predicted a greater hazard for acute kidney injury (HR, 1.12) and hypotensive events (HR, 1.12). Visit-to-visit DBP variability independently predicted worse cardiovascular outcomes and hypoperfusion-related adverse events in SPRINT.