Increasing Blood Pressure Variability Predicts Poor Functional Outcome Following Acute Stroke

Reviving Decades-Old Wisdom: Longitudinal Analysis of Renin-Angiotensin System Inhibitors and Its Effects on Acute Ischemic Stroke to Improve Outcomes

BACKGROUND

While renin-angiotensin system (RAS) inhibitors have a longstanding history in blood pressure control, their suitability as first-line in-patient treatment may be limited due to prolonged half-life and kidney failure concerns.

METHODS

Using a cohort design, we assessed the impact of RAS inhibitors, either alone or in combination with beta-blockers, on mortality, while exploring interactions, including those related to end-stage renal disease and serum creatinine levels. Eligible subjects were Acute Ischemic Stroke (AIS) patients aged 18 or older with specific subtypes who received in-patient antihypertensive treatment. The primary outcome was mortality rates. Statistical analyses included cross-sectional and longitudinal approaches, employing generalized linear models, G-computation, and discrete-time survival analysis over a 20-day follow-up period.

RESULTS

In our study of 3,058 AIS patients, those using RAS inhibitors had significantly lower in-hospital mortality (2.2%) compared to non-users (12.1%), resulting in a relative risk (RR) of 0.18 (95% CI: 0.12-0.26). Further analysis using G-computation revealed a marked reduction in mortality risk associated with RAS inhibitors (0.0281 vs. 0.0913, risk difference [RD] of 6.31% or 0.0631, 95% CI: 0.046-0.079). Subgroup analysis demonstrated notable benefits, with individuals having creatinine levels below and above 1.3 mg/dl exhibiting statistically significant RD (RD -0.0510 vs. -0.0895), and a significant difference in paired comparison (-0.0385 or 3.85%, CI 0.023-0.054). Additionally, longitudinal analysis confirmed a consistent daily reduction of 0.93% in mortality risk associated with the intake of RAS inhibitors.

CONCLUSIONS

RAS inhibitors are associated with a significant reduction in in-hospital mortality in AIS patients, suggesting potential clinical benefits in improving patient outcomes.

Twenty-four-hour ambulatory blood pressure variability and association with ischemic stroke subtypes in the subacute stage

Background and purpose

Blood pressure (BP) variability (BPV) increases the risk of cerebral disease in both hemorrhagic and ischemic strokes. However, whether BPV is associated with different types of ischemic stroke remains unclear. In this study, we explored the relationship between BPV and ischemic stroke subtypes.

Methods

We enrolled consecutive patients aged 47-95 years with ischemic stroke in the subacute stage. We categorized them into four groups based on their artery atherosclerosis severity, brain magnetic resonance imaging markers, and disease history: large-artery atherosclerosis, branch atheromatous disease, small-vessel disease, and cardioembolic stroke. Twenty-four-hour ambulatory blood pressure monitoring was performed, and the mean systolic blood pressure/diastolic blood pressure, standard deviation, and coefficient of variation were calculated. A multiple logistic regression model and random forest were used to test the relationship between BP and BPV in the different types of ischemic stroke.

Results

A total of 286 patients, including 150 men (73.0 ± 12.3 years) and 136 women (77.8 ± 9.6 years) were included in the study. Of these, 86 (30.1%) patients had large-artery atherosclerosis, 76 (26.6%) had branch atheromatous disease, 82 (28.7%) had small-vessel disease, and 42 (14.7%) had cardioembolic stroke. There were statistically significant differences in BPV between subtypes of ischemic stroke in 24-h ambulatory blood pressure monitoring. The random forest model showed that BP and BPV were important features associated with ischemic stroke. Multinomial logistic regression analysis demonstrated that systolic blood pressure levels; systolic blood pressure variability at 24 h, daytime and nighttime; and nighttime diastolic blood pressure were independent risk factors for large-artery atherosclerosis after adjustment for confounders. When compared to branch atheromatous disease and small-vessel disease, nighttime diastolic blood pressure and standard deviation of diastolic blood pressure were significantly associated with patients in the cardioembolic stroke group. However, a similar statistical difference was not seen in patients with large-artery atherosclerosis.

Conclusion

The results of this study indicate a discrepancy in blood pressure variability among different ischemic stroke subtypes during the subacute stage. Higher systolic blood pressure and systolic blood pressure variability during the 24 h, daytime, and nighttime, and nighttime diastolic blood pressure were independent predictors for large-artery atherosclerosis stroke. Increased nighttime diastolic BPV was an independent risk factor for cardioembolic stroke.

Blood pressure variability and the development of hypertensive organ damage in the general population

Increasing blood pressure variability (BPV) has been reported to be a strong predictor of cardiovascular events in patients with hypertension. However, the effects of BPV in the general population have not been intensively studied. The present study was designed to investigate a possible relationship between year-to-year BPV and hypertensive target organ damage (TOD) in a relatively low-risk general population. A total of 5489 consecutive patients (mean age 58.6 ± 10.7 years) who visited our hospital for an annual physical checkup for five consecutive years during 2008-2013 were enrolled in this study. The average systolic and diastolic blood pressures and pulse pressure were calculated, as well as standard deviation, coefficient of variation, and average real variability in blood pressures. Cross-sectional analysis was conducted and subjects without TOD at baseline (n = 3115) were followed up (median 1827 days) with the endpoint of TOD, defined as left ventricular hypertrophy on electrocardiogram or declining glomerular filtration rate. At baseline, BPV was closely associated with TOD. During follow-up, left ventricular hypertrophy and declining glomerular filtration rate developed in 189 and 400 subjects, respectively. Although the standard deviation for systolic blood pressure and pulse pressure predicted future development of TOD in a univariate analysis, BPV was not a significant determinant of incident TOD in adjusted Cox hazard models. These results suggest that year-to-year BPV is a marker of the presence of TOD in the general population but does not independently predict future TOD.

Blood Pressure Variability After Cerebrovascular Events—A Possible New Therapeutic Target: A Narrative Review

Blood pressure variability, the variation of blood pressure during a certain period, results from the interaction of hemodynamic, neuronal, humoral, behavioral, and environmental factors. Cerebral autoregulation is impaired in acute cerebrovascular disease. In these patients, increased blood pressure variability may provoke or exacerbate secondary brain injury. In fact, available data showed that increased Blood pressure variability is associated with worse outcomes after acute ischemic stroke, intracerebral hemorrhage, and aneurysmal subarachnoid hemorrhage. Consequently, blood pressure variability may represent a usual modifiable therapeutic target. This concept this particularly attractive because reduction of blood pressure variability can be feasible in regions with lower resources and can be applicable to patients with various forms of acute stroke. Prospective studies are needed to further clarify the relationship between blood pressure variability and secondary brain damage, and the determinants of blood pressure variability in different clinical populations. Ultimately, cerebrovascular disease-specific randomized controlled trials aimed at reducing blood pressure variability, irrespective of the absolute blood pressure values, are needed to determine if reduction of blood pressure variability can improve outcomes in patients with acute cerebrovascular disease.

Comparison of Intravenous Antihypertensives on Blood Pressure Control in Acute Neurovascular Emergencies: A Systematic Review

BACKGROUND

Acute blood pressure (BP) management in neurologic patients is paramount. Different neurologic emergencies dictate various BP goals. There remains a lack of literature determining the optimal BP regimen regarding safety and efficacy. The objective of this study was to identify which intravenous antihypertensive is the most effective and safest for acute BP management in neurologic emergencies.

METHODS

Ovid EBM (Evidence Based Medicine) Reviews, Ovid Embase, Ovid Medline, Scopus, and Web of Science Core Collection were searched from inception to August 2020. Randomized controlled trials or comparative observational studies that evaluated clevidipine, nicardipine, labetalol, esmolol, or nitroprusside for acute neurologic emergencies were included. Outcomes of interest included mortality, functional outcome, BP variability, time to goal BP, time within goal BP, incidence of hypotension, and need for rescue antihypertensives. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to evaluate the degree of certainty in the evidence available.

RESULTS

A total of 3878 titles and abstracts were screened, and 183 articles were selected for full-text review. Ten studies met the inclusion criteria; however, the significant heterogeneity and very low quality of studies precluded a meta-analysis. All studies included nicardipine. Five studies compared nicardipine with labetalol, three studies compared nicardipine with clevidipine, and two studies compared nicardipine with nitroprusside. Compared with labetalol, nicardipine appears to reach goal BP faster, have less BP variability, and need less rescue antihypertensives. Compared with clevidipine, nicardipine appears to reach goal BP goal slower. Lastly, nicardipine appears to be similar for BP-related outcomes when compared with nitroprusside; however, nitroprusside may be associated with increased mortality. The confidence in the evidence available for all the outcomes was deemed very low.

CONCLUSIONS

Because of the very low quality of evidence, an optimal BP agent for the treatment of patients with neurologic emergencies was unable to be determined. Future randomized controlled trials are needed to compare the most promising agents.