Level of systolic blood pressure within the normal range and risk of recurrent stroke

Systolic BP and Mortality in Older Adults with CKD

BACKGROUND AND OBJECTIVES

Optimal BP targets for older adults with CKD are unclear. This study sought to determine whether a nonlinear relationship between BP and mortality-as described for the broader CKD population and for older adults in the general population-is present for older adults with CKD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A cohort of 21,015 adults age 65-105 years with a moderate or severe reduction in eGFR (<60 ml/min per 1.73 m(2)) were identified within the Kaiser Permanente Northwest Health Maintenance Organization population. The relationship between baseline systolic BP (SBP; ≤120, 121-130, 131-140, 141-150, >150 mmHg; referent, 131-140 mmHg) and all-cause mortality across age groups (65-70, 71-80, and >80 years) was examined; patients were followed for up to 11 years after cohort entry.

RESULTS

The median times at risk were 3.15 years, 3.53 years, and 2.76 years for adults age 65-70, 71-80, and >80 years, respectively. Mortality during follow-up was 19.6% for those age 65-70 years, 33.4% for those age 71-80 years, and 55.7% for those age >80 years. The relationship between SBP and mortality varied as a function of age. The risk of death was highest for patients with the lowest SBP in all age groups. Only among adults age 65-70 years was an SBP>140 mmHg associated with a higher risk of death compared with the referent category. Patterns of age modification of the relationship between SBP and mortality were consistent in all sensitivity analyses.

CONCLUSIONS

In a cohort of older adults, the relationship between SBP and mortality varied systematically with age. A relationship between higher SBP and mortality was present only for younger members of this cohort and not for those older than 70. These results raise the question of whether the relative benefits and harms of lowering BP to recommended targets for older adults with CKD may vary as a function of age.

Systolic Blood Pressure Control and Mortality After Stroke in Hypertensive Patients

BACKGROUND AND PURPOSE

Hypertensive patients with electrocardiographic left ventricular hypertrophy are at increased risk of all-cause and cardiovascular death. Lowering blood pressure (BP) after stroke reduces the risk of recurrent stroke, but recent data suggest that lower systolic BP (SBP) measured 5 years after stroke is associated with increased mortality. Whether lower SBP is associated with increased short-term mortality after stroke in hypertensive patients is unclear.

METHODS

All-cause and cardiovascular mortality were examined in relation to average on-treatment SBP after stroke in 541 hypertensive patients with electrocardiographic left ventricular hypertrophy randomly assigned to losartan- or atenolol-based treatment who had new strokes during follow-up. Patients with on-treatment SBP<144 mm Hg (lowest tertile) and SBP>157 (highest tertile) were compared with patients with average SBP between 144 and 157.

RESULTS

During 2.02±1.65 years mean follow-up after incident stroke, 170 patients (31.4%) died, 135 (25.0%) from cardiovascular causes. In multivariate Cox analyses, adjusting for significant univariate predictors of mortality, compared with average SBP between 144 and 157, an average SBP<144 was a significant predictor of all-cause (hazard ratio, 1.81; 95% confidence interval, 1.20-2.73) and cardiovascular mortality (hazard ratio, 1.60; 95% confidence interval, 1.02-2.54), whereas patients who had an average SBP>157 had no significant increased risk of death.

CONCLUSIONS

Lower achieved SBP (<144 mm Hg) is associated with a significantly increased risk of cardiovascular and all-cause mortality after initial stroke in hypertensive patients during short-term follow-up. Further study is required to determine ideal SBP goals after stroke.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov/. Unique identifier: NCT00338260.

Blood Pressure Goals and Targets in the Elderly

OPINION STATEMENT

The American College of Cardiology (ACC)/American Heart Association (AHA) 2011 expert consensus document on hypertension in the elderly recommends that the blood pressure be reduced to less than 140/90 mmHg in adults aged 60-79 years and the systolic blood pressure to 140 to 145 mmHg if tolerated in adults aged 80 years and older. I strongly support these guidelines based on clinical trial data, especially from the Systolic Hypertension in the Elderly trial and from the Hypertension in the Very Elderly trial (HYVET). Other guidelines supporting reducing the blood pressure to less than 140/90 mmHg in adults aged 60 to 79 years of age include the European Society of Hypertension (ESH)/European Society of Cardiology (ESC) 2013 guidelines, the minority report from the 2013 Eighth Joint National Committee (JNC 8) guidelines, the 2013 Canadian Hypertension Education Program guidelines, the 2011 UK guidelines, the 2014 American Society of Hypertension (ASH)/International Society of Hypertension (ISH) guidelines, and the 2015 AHA/ACC/ASH scientific statement on treatment of hypertension in patients with coronary artery disease. I support these guidelines. In adults aged 80 years and older, a blood pressure below 150/90 mm Hg has been recommended by these guidelines, with a target goal of less than 140/90 mmHg considered in those with diabetes mellitus or chronic kidney disease. I support these guidelines. The 2013 JNC 8 guidelines recommend reducing the blood pressure to less than 140/90 mmHg in adults aged 60 years and older with diabetes mellitus or chronic kidney disease but to less than 150/90 mmHg in adults aged 60 years and older without diabetes mellitus or chronic kidney disease. I strongly disagree with this recommendation and am very much concerned that the higher systolic blood pressure goal recommended by JNC 8 guidelines in adults aged 60 years and older without diabetes mellitus or chronic kidney disease will lead to an increase in cardiovascular events and mortality in these adults.

Evidence for Cerebral Hemodynamic Measurement-based Therapy in Symptomatic Major Cerebral Artery Disease

In patients with atherosclerotic internal carotid artery or middle cerebral artery occlusive disease, chronic reduction in cerebral perfusion pressure (chronic hemodynamic compromise) increases the risk of ischemic stroke and can be detected by directly measuring hemodynamic parameters. However, strategies for selecting treatments based on hemodynamic measurements have not been clearly established. Bypass surgery has been proven to improve hemodynamic compromise. However, the benefit of bypass surgery for reducing the stroke risk in patients with hemodynamic compromise is controversial. The results of the two randomized controlled trials were inconsistent. Hypertension is a major risk factor for stroke, and antihypertensive therapy provides general benefit to patients with symptomatic atherosclerotic major cerebral artery disease. However, the benefit of strict control of blood pressure for reducing the stroke risk in patients with hemodynamic compromise is a matter of debate. The results of the two observational studies were different. We must establish strategies for selecting treatments based on hemodynamic measurements in atherosclerotic major cerebral artery disease.

The Korean Society of Hypertension Guidelines for the Management of Hypertension in 2013: Its Essentials and Key Points

The Korean Society of Hypertension published new guidelines for the management of hypertension in 2013 which fully revised the first Korean hypertension treatment guideline published in 2004. Due to shortage of Korean data, the Committee decided to establish the guideline in the form of an 'adaptation' of the recently released guidelines. The prevalence of hypertension was 28.5% in the recent Korean National Health and Nutrition Examination Survey in 2011, and the awareness, treatment, and control rates are generally improving. However, the risks for cerebrovascular disease and coronary artery disease which are attributable to hypertension were the highest in Korea. The classification of hypertension is the same as in other guidelines. The remarkable difference is that prehypertension is further classified as stage 1 and 2 prehypertension because the cardiovascular risk is significantly different within the prehypertensive range. Although the decision-making was based on office blood pressure (BP) measured by the auscultation method using a stethoscope, the importance of home BP measurement and ambulatory BP monitoring is also stressed. The Korean guideline does not recommend a drug therapy in patients within the prehypertensive range, even in patients with prediabetes, diabetes mellitus, stroke, or coronary artery disease. In an elderly population over 65 years old, drug therapy can be initiated when the systolic BP (SBP) is ≥160 mm Hg. The target BP is generally an SBP of <140 mm Hg and a diastolic BP (DBP) of <90 mm Hg regardless of previous cardiovascular events. However, in patients with hypertension and diabetes, the lower DBP control <85 mm Hg is recommended. Also, in patients with hypertension with prominent albuminuria, a more strict SBP control <130 mm Hg can be recommended. In lifestyle modification, sodium reduction is the most important factor in Korea. Five classes of antihypertensive drugs, including angiotensin-converting enzyme inhibitors, β-blockers, calcium antagonists, and diuretics, are equally recommended as a first-line treatment, whereas a combination therapy chosen from renin-angiotensin system inhibitors, calcium antagonists, and diuretics is preferentially recommended.

2013 Korean Society of Hypertension guidelines for the management of hypertension. Part II-treatments of hypertension

Treatment strategies are provided in accordance with the level of global cardiovascular risk, from lifestyle modification in the lower risk group to more comprehensive treatment in the higher risk group. Considering the common trend of combination drug regimen, the choice of the first drug is suggested more liberally according to the physician's discretion.

Pharmacological treatment and prevention of cerebral small vessel disease: a review of potential interventions

Small vessel disease encompasses lacunar stroke, white matter hyperintensities, lacunes and microbleeds. It causes a quarter of all ischemic strokes, is the commonest cause of vascular dementia, and the cause is incompletely understood. Vascular prophylaxis, as appropriate for large artery disease and cardioembolism, includes antithrombotics, and blood pressure and lipid lowering; however, these strategies may not be effective for small vessel disease, or are already used routinely so precluding further detailed study. Further, intensive antiplatelet therapy is known to be hazardous in small vessel disease through enhanced bleeding. Whether acetylcholinesterase inhibitors, which delay the progression of Alzheimer's dementia, are relevant in small vessel disease remains unclear. Potential prophylactic and treatment strategies might be those that target brain microvascular endothelium and the blood brain barrier, microvascular function and neuroinflammation. Potential interventions include endothelin antagonists, neurotrophins, nitric oxide donors and phosphodiesterase 5 inhibitors, peroxisome proliferator‐activated receptor‐gamma agonists, and prostacyclin mimics and phosphodiesterase 3 inhibitors. Several drugs that have relevant properties are licensed for other disorders, offering the possibility of drug repurposing. Others are in development. Since influencing multiple targets may be most effective, using multiple agents and/or those that have multiple effects may be preferable. We focus on potential small vessel disease mechanistic targets, summarize drugs that have relevant actions, and review data available from randomized trials on their actions and on the available evidence for their use in lacunar stroke.

Causes of death among persons who survive an acute ischemic stroke

Stroke and especially its complications are a leading cause of death. Despite reduced morbidity in some developed countries, mortality in stroke patients is still high worldwide. In the past decades, treatment of acute stroke has focused on early intervention, such as revascularization and cerebral edema prevention. However, long-term clinical observations indicate that poststroke pneumonia, cardiovascular complications, and vascular embolism are the major reasons for the increased death rate after stroke. Few evidence-based data are available currently to guide the management of these complications. Thus, systematic studies of these adverse events are essential and urgent to improve survival after stroke.

Low systolic blood pressure and mortality from all-cause and vascular diseases among the rural elderly in Korea; Kangwha cohort study

The association between low systolic blood pressure (SBP) and vascular diseases is unclear. The aim of this study was to prospectively examine the association between SBP, especially low SBP, and mortality from all causes and vascular diseases among the elderly in Korea. Six thousand two hundred ninety four residents in a rural community were followed-up for deaths from 1985 to 2008. The adjusted hazard ratios (aHR) and 95% confidence intervals were calculated by Cox proportional hazard model. A stratified analysis was conducted by age at enrollment. Among the elderly aged 65 and above, the lowest SBP (<100 mm Hg) group had an elevated aHR for mortality from vascular diseases (aHR = 2.1, 95% CI = 1.2-3.9) including stroke (aHR = 2.4, 95% CI = 0.9-6.3) and ischemic heart diseases (aHR = 5.1, 95% CI = 1.0-26.0) compared to those with SBP of 100-119 mm Hg, while higher SBP was associated with higher mortality. This J-curve association was generally maintained when analysis was restricted to those with fair or good self-rated health, or those with no known vascular diseases. In people below 65, increasing SBP nearly monotonically increased the mortality from all-cause and vascular diseases. Our results suggest that elderly persons with low SBP should be treated with caution, since low SBP may increase vascular mortality.

Low blood pressure during the acute period of ischemic stroke is associated with decreased survival

OBJECTIVES

There is no agreement on optimal blood pressure (BP) level during the acute phase of stroke, because studies on the relation between BP and stroke outcome have shown contradicting results. The aim of this study was to compare the relationship of admission, maximal, discharge BP and its components during hospitalization for the first-ever acute ischemic stroke with total mortality after stroke.

METHODS

In 532 consecutive patients (mean age 66 ± 10 years, 59% of men) hospitalized for their first-ever ischemic stroke, the association between BP and total mortality during a median follow-up of 66 weeks (interquartile range 33-119 weeks) was analyzed.

RESULTS

In multivariate analysis, both admission mean BP (MBP) and discharge SBP quartiles were independent predictors of mortality and outperformed other parameters of BP. After multivariate adjustments, patients with admission MBP below 100 mmHg had a higher risk of death than those with MBP between 100-110 and 110-121 mmHg, whereas the risk of mortality did not differ from the group with admission MBP above 122 mmHg. Similarly, patients with discharge SBP below 120 mmHg had an increased risk of death as compared to groups with SBP between 120-130 and 130-141 mmHg, whereas the risk of death was similar to that with discharge SBP above 141 mmHg.

CONCLUSION

Among patients hospitalized for their first-ever ischemic stroke, the risk of all-cause death is significantly increased in those with admission MBP below 100 mmHg and discharge SBP below 120 mmHg, even after adjustments for other confounders.

Degree of blood pressure reduction and recurrent stroke: the PROGRESS trial

OBJECTIVE

There is ongoing controversy regarding a 'J-curve' phenomenon such that low and high blood pressure (BP) levels are associated with increased risks of recurrent stroke. We aimed to determine whether large treatment-related BP reductions are associated with increased risks of recurrent stroke.

DESIGN

Data are from the PROGRESS trial, where 6105 patients with cerebrovascular disease were randomly assigned to either active treatment (perindopril ± indapamide) or placebo(s). There were no BP criteria for entry. BP was measured at every visit, and participant groups defined by reduction in systolic BP (SBP) from baseline were used for the analyses. Outcome was recurrent stroke.

RESULTS

During a mean follow-up of 3.9 years, 727 recurrent strokes were observed. There were clear associations between the magnitude of SBP reduction and the risk of recurrent stroke. After adjustment for cardiovascular risk factors and randomised treatment, annual incidence was 2.08%, 2.10%, 2.31% and 2.96% for participant groups defined by SBP reductions of ≥ 20, 10-19, 0-9 and <0 mm Hg, respectively (p=0.0006 for trend).

CONCLUSIONS

The present analysis provided no evidence of an increase in recurrent stroke associated with larger reductions in SBP produced by treatment among patients with cerebrovascular disease.

Prevalence and control of hypertension and albuminuria in South Korea: focus on obesity and abdominal obesity in the Korean National Health and Nutrition Examination Survey, 2011-2012

BACKGROUND

Albuminuria is associated with cardiovascular disease, and the relationship between albuminuria and hypertension is well established in many studies. So the control of hypertension is critical for decreasing cardiovascular events and albuminuria. Obesity and abdominal obesity are also associated with hypertension and albuminuria. Therefore, we analyzed the relationship between albuminuria and the prevalence and control of hypertension in the general Korean population according to obesity status.

METHODS

We analyzed data from the 2011-2012 Korea National Health and Nutrition Examination Survey, and 9,519 subjects were included. Subjects were divided into four groups: non-obese/normal waist circumference, non-obese/high waist circumference, obese/normal waist circumference, and obese/high waist circumference.

RESULTS

Systolic blood pressure and diastolic blood pressure were positively associated with albumin-creatinine ratio in all groups (all p values <0.005). Non-obese/normal waist circumference group were more likely to have hypertension (odds ratios [95% confidential intervals (CIs)] were 3.20 [2.21-4.63] in microalbuminuria level and 3.09 [1.05-9.14] in macroalbuminuria level), and less likely to have controlled hypertension (odds ratios <1 for both albuminuria levels) after adjusting for all covariates. Obese/normal waist circumference group were also more likely to have hypertension (odds ratio [95% CI] were 3.10 [1.56-6.15] in microalbuminuria level and 21.75 [3.66-129.04] in macroalbuminuria level), and less likely to have controlled hypertension in macroalbuminuria level (odds ratio [95% CI], 0.04 [0.01-0.15]).

CONCLUSIONS

Non-obese and normal waist circumference subjects have an increased prevalence and decreased control of hypertension in microalbuminuria and macroalbuminuria levels. Screening for albuminuria may provide helpful information about hypertension and blood pressure control, particularly in the non-obese and normal waist circumference subjects.

Systolic and diastolic blood pressure changes in relation with myocardial infarction and stroke in patients with coronary artery disease

Excessively high and low achieved blood pressure (BP) may be associated with a bad outcome in patients with coronary artery disease, the J curve phenomenon. The effect of BP changes from baseline in relation with the subsequent risk of stroke and myocardial infarction (MI) is unknown. Of the 25 620 patients randomized in the Ongoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) study, we selected 19 102 patients with coronary artery disease at baseline. BP at entry was 141/82 mm Hg, and its average decrease during follow-up was 7/6 mm Hg. BP entered the analysis as time-varying variable modeled with restricted cubic splines. After adjustment for several potential determinants of reverse causality, a change in BP from baseline by -34/-21 mm Hg (10th percentile) was associated with a lesser risk of stroke without any significant increase in the risk of MI. A rise in systolic/diastolic BP from baseline by 20/10 mm Hg (90th percentile) was associated with an increased risk of stroke, whereas the risk of MI increased with systolic BP and not with diastolic BP. In conclusion, in patients with coronary artery disease and initially free from congestive heart failure, a BP reduction from baseline over the examined BP range had little effect on the risk of MI and predicted a lower risk of stroke. An increase in systolic BP from baseline increased the risk of stroke and MI. The relationships of BP with risk were much steeper for stroke than for MI. A treatment-induced BP reduction over the explored range seems to be safe in patients with coronary artery disease.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00153101.

Treating hypertension and prehypertension in older people: when, whom and how

Prehypertension should be treated with lifestyle measures and not with antihypertensive drug therapy in older adults. Lifestyle measures should be encouraged both to retard development of hypertension and as adjunctive therapy in those with hypertension. A meta-analysis of 11 randomized controlled trials of 40,325 older persons showed that antihypertensive drug therapy significantly reduced all-cause mortality 13% (7-19%), cardiovascular death 18% (7-27%), cardiovascular events 21% (13-27%), stroke 30% (23-37%), and fatal stroke by 33% (9-50%) (Ostrowski et al., 2014 [32]). The American College of Cardiology/American Heart Association 2011 expert consensus document on hypertension in the elderly recommended that the systolic blood pressure be lowered to <140 mm Hg in older persons younger than 80 years and to 140-145 mm Hg if tolerated in adults aged 80 years and older. A meta-analysis of 147 randomized trials including 464,000 persons with hypertension showed that except for the extra protective effect of beta blockers given after myocardial infarction and a minor additional effect of calcium channel blockers in preventing stroke, the use of beta blockers, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), diuretics, and calcium channel blockers cause a similar reduction in coronary events and stroke for a given decrease in blood pressure. The choice of specific antihypertensive drugs such as diuretics, ACE inhibitors, ARBs, beta blockers, or calcium channel blockers depends on efficacy, tolerability, presence of specific comorbidities and cost.

The J-curve in arterial hypertension: fact or fallacy?

It is known that a large proportion of patients with arterial hypertension are undertreated. This may result in an increase of the incidence of cardiovascular events. On the other hand, aggressive reduction of blood pressure may increase cardiovascular events (J-curve phenomenon) in certain populations. This phenomenon may be seen in patients with coronary artery disease and left ventricular hypertrophy when the diastolic blood pressure decreases below 70-80 mm Hg, and the systolic blood pressure decreases below 130 mm Hg. This phenomenon is not seen in patients with stroke or renal disease. Thus, a safer and more conservative strategy should be applied in patients with coronary artery disease, left ventricular hypertrophy, elderly, and in patients with isolated systolic hypertension. This is depicted in the recently published European Society of Hypertension/European Society of Cardiology guidelines in which higher targets of blood pressure are suggested in certain cardiovascular diseases and in the elderly.

Lowering blood pressure to prevent stroke recurrence: a systematic review of long-term randomized trials

Albeit hypertension is a leading risk factor for an initial stroke, the role of blood pressure (BP) lowering to prevent a subsequent stroke is controversial. The present systematic review searched randomized trials published from January 1990 to January 2014 with the aim to assess antihypertensive treatment effects on recurrent stroke prevention. Seven randomized placebo-controlled trials enrolling 49,518 patients, two randomized trials not placebo controlled comparing antihypertensive drugs, and one randomized trial that compared the effects of intensive systolic BP lowering with a more conservative systolic BP management, were identified. The placebo-controlled trials had substantial methodological differences, explaining the difficulties to compare their results. An important obstacle arises from the large dispersion in the window's time between the qualifying stroke and randomization. Another barrier is the variation among studies in the recruited patient's stroke subtypes. Differences between trials could not be attributed to disparity in lowering BP or to different degrees of no adherence. The American Heart Association/American Stroke Association stated that although an absolute target of BP level has not been clearly defined, a reduction in recurrent stroke has been associated with an average lowering of 10/5 mm Hg. It should be taken into account that it is not advisable to reduce BP levels to <120/80 mm Hg. It should carry out an individualized selection, based on demographic characteristics and comorbidities (cardiovascular disease, diabetes mellitus, and chronic disease) among diuretics, angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, or calcium channel blockers.

Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

Comparative review of the blood pressure-lowering and cardiovascular benefits of telmisartan and perindopril

Hypertension is a major cardiovascular (CV) risk factor, and blood pressure (BP)-lowering treatment substantially reduces the risk. This review compares the available clinical evidence from the BP-lowering and CV-outcome studies of telmisartan and perindopril, which are among the most intensively studied members of their respective classes. The PubMed database was searched for telmisartan and perindopril publications meeting the following criteria: 1) head-to-head comparison trials for BP lowering; and 2) CV-outcome studies (ie, ones with a CV event, mortality, or hospitalization outcome) in patients with CV risk factors but without heart failure. In comparative trials, telmisartan treatment resulted in significantly higher reduction in trough BP and mean ambulatory diastolic BP for the last 8 hours of the dosing interval compared with perindopril. In mainly placebo-controlled CV-outcome studies in patients with hypertension, CV benefits with perindopril were associated with large reductions in BP. There were no CV outcome studies with telmisartan in patients with hypertension. The beyond-BP-lowering CV-protective benefits of telmisartan were demonstrated in the active-controlled ONTARGET (ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial) trial, which included patients with controlled BP at baseline. In general, the trials discussed in this review reinforce the fact that perindopril and telmisartan are two long-acting antihypertensive drugs that reduce BP over 24 hours, and are the best-evidenced drugs in their class with proven CV protection. It is also clear that the benefits are not a “class effect”, and vary between the different drugs within each class. Hence, the best approach for treatments tailored to individual patient needs should be evidence-based specific drugs, rather than a drug-class recommendation for achieving therapeutic targets.

Risk factor management for stroke prevention

PURPOSE OF REVIEW

This review focuses on the recommendations for management of hypertension, dyslipidemia, diabetes mellitus, diet, physical activity, and lifestyle choices commonly encountered in neurologic practice. Specific studies, including those relevant to lipid targets, blood pressure targets, and adherence to medications after stroke, are reviewed.

RECENT FINDINGS

In addition to traditional risk factors such as hypertension, dyslipidemia, and diabetes mellitus, this review discusses sleep apnea, diet, physical activity, and other novel risk factors that are potentially modifiable. Recent studies confirm that pharmacologic strategies to achieve aggressive targets for lipid and blood pressure lowering have significant impact on recurrent stroke risk.

SUMMARY

Optimal secondary prevention strategies can prevent as much as 80% of all recurrent strokes.

Differences in ischemic and hemorrhagic recurrence rates among race-ethnic groups in the PRoFESS secondary stroke prevention trial

BACKGROUND AND AIMS

Epidemiological studies show that vascular risk factors are the same across the world but their effect vary between different race-ethnic groups. However, few studies have evaluated differences in recurrent stroke rates in various race-ethnicities. In >20 000 patients spanning 35 countries encompassing most race-ethnicities, we evaluated the incidence of ischemic and hemorrhagic strokes and myocardial infarction in patients within the context of the largest secondary stroke prevention trial (Prevention Regimen for Effectively Avoiding Secondary Strokes) to identify any significant differences.

METHODS

There were 20 332 patients with a recent ischemic stroke randomized in a factorial design to receive the antiplatelet agent clopidogrel vs. aspirin plus extended-release dipyridamole, and 80 mg of the anthypertensive telmisartan vs. placebo. The primary outcome for the trial was the time to any recurrent stroke. Statistical analysis was used to detect race-ethnic differences in recurrent vascular events.

RESULTS

Mean patient age was 66 (±8·6) years and 36% were women. The study included 58% European/Caucasian, 33% Asians, 5% Latin/Hispanic, and 4% Black African. There were 74% of patients that were hypertensive, and average systolic and diastolic blood pressure was 144·1/83·8 mmHg. There was at least one significant difference in the overall test of all race-ethnic groups in myocardial infarction and symptomatic intracerebral hemorrhage occurrence. In the Kaplan-Meier hemorrhage and stroke-free survival curves, Asians showed a significantly higher recurrence of ischemic stroke risk in the 135-150 mmHg and greater than 150 mm Hg blood pressure groups, and a greater risk of hemorrhage recurrence in the greater than 150 mmHg blood pressure group.

CONCLUSIONS

We found a significant difference in myocardial infarction and symptomatic intracerebral hemorrhage recurrence among different race-ethnic groups. The risk of recurrent ischemic and hemorrhagic stroke was greater in Asians with high blood pressure.

Lower stroke risk with lower blood pressure in hemodynamic cerebral ischemia

OBJECTIVE

To determine whether strict blood pressure (BP) control is the best medical management for patients with symptomatic carotid artery occlusion and hemodynamic cerebral ischemia.

METHODS

In this prospective observational cohort study, we analyzed data from 91 participants in the nonsurgical group of the Carotid Occlusion Surgery Study (COSS) who had recent symptomatic internal carotid artery occlusion and hemodynamic cerebral ischemia manifested by ipsilateral increased oxygen extraction fraction. The target BP goal in COSS was ≤130/85 mm Hg. We compared the occurrence of ipsilateral ischemic stroke during follow-up in the 41 participants with mean BP ≤130/85 mm Hg to the remaining 50 with higher BP.

RESULTS

Of 16 total ipsilateral ischemic strokes that occurred during follow-up, 3 occurred in the 41 participants with mean follow-up BP of ≤130/85 mm Hg, compared to 13 in the remaining 50 participants with mean follow-up BP >130/85 mm Hg (hazard ratio 3.742, 95% confidence interval 1.065-13.152, log-rank p = 0.027).

CONCLUSION

BPs ≤130/85 mm Hg were associated with lower subsequent stroke risk in these patients.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that control of hypertension ≤130/85 mm Hg is associated with a reduced risk of subsequent ipsilateral ischemic stroke in patients with recently symptomatic carotid occlusion and hemodynamic cerebral ischemia (increased oxygen extraction fraction).

Hypertension and hypertensive encephalopathy

The definition of hypertension has continuously evolved over the last 50 years. Hypertension is currently defined as a blood pressure greater than 140/90mmHg. One in every four people in the US has been diagnosed with hypertension. The prevalence of hypertension increases further with age, affecting 75% of people over the age of 70. Hypertension is by far the most common risk factor identified in stroke patients. Hypertension causes pathologic changes in the walls of small (diameter<300 microns) arteries and arterioles usually at short branches of major arteries, which may result in either ischemic stroke or intracerebral hemorrhage. Reduction of blood pressure with diuretics, β-blockers, calcium channel blockers, and angiotensin-converting enzyme (ACE) inhibitors have all been shown to markedly reduce the incidence of stroke. Hypertensive emergency is defined as a blood pressure greater than 180/120mmHg with end organ dysfunction, such as chest pain, shortness of breath, encephalopathy, or focal neurologic deficits. Hypertensive encephalopathy is believed to be caused by acute failure of cerebrovascular autoregulation. Hypertensive emergency is treated with intravenous antihypertensive agents to reduce blood pressure by 25% within the first hour. Selective inhibition of cerebrovascular blood vessel permeability for the treatment of hypertensive emergency is beginning early clinical trials.

Is the association of diabetes with uncontrolled blood pressure stronger in Mexican Americans and blacks than in whites among diagnosed hypertensive patients?

BACKGROUND

Clinical evidence shows that diabetes may provoke uncontrolled blood pressure (BP) in hypertensive patients. However, racial differences in the associations of diabetes with uncontrolled BP outcomes among diagnosed hypertensive patients have not been evaluated.

METHODS

A total of 6,134 diagnosed hypertensive subjects aged ≥ 20 years were collected from the National Health and Nutrition Examination Survey 1999-2008 with a stratified multistage design. Odds ratios (ORs) and relative ORs of uncontrolled BP and effect differences in continuous BP for diabetes over race/ethnicity were derived using weighted logistic regression and linear regression models.

RESULTS

Compared with participants who did not have diabetes, non-Hispanic black participants with diabetes had a 138% higher chance of having uncontrolled BP, Mexican participants with diabetes had a 60% higher chance of having uncontrolled BP, and non-Hispanic white participants with diabetes had a 161% higher chances of having uncontrolled BP. The association of diabetes with uncontrolled BP was lower in Mexican Americans than in non-Hispanic blacks and whites (Mexican Americans vs. non-Hispanic blacks: relative OR = 0.55, 95% confidence interval (CI) = 0.37-0.82; Mexican Americans vs. non-Hispanic whites: relative OR = 0.53, 95% CI = 0.35-0.80) and the association of diabetes with isolated uncontrolled systolic BP was lower in Mexican Americans than in non-Hispanic whites (Mexican Americans vs. non-Hispanic whites: relative OR = 0.62, 95% CI = 0.40-0.96). Mexican Americans have a stronger association of diabetes with decreased systolic BP and diastolic BP than non-Hispanic whites, and a stronger association of diabetes with decreased diastolic BP than non-Hispanic blacks.

CONCLUSIONS

The association of diabetes with uncontrolled BP outcomes is lower despite higher prevalence of diabetes in Mexican Americans than in non-Hispanic whites. The stronger association of diabetes with BP outcomes in whites should be of clinical concern, considering they account for the majority of the hypertensive population in the United States.

The expression of angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor axis are upregulated after acute cerebral ischemic stroke in rats

There is now unequivocal evidence that the angiotensin-converting enzyme 2(ACE2)-Ang-(1-7)-Mas axis is a key component of the renin-angiotensin system (RAS) cascade, which is closely correlated with ischemic insult occurrence. Our previous studies demonstrated that the Ang-(1-7), was an active member of the brain RAS. However, the ACE2-Ang-(1-7)-Mas axis expression after cerebral ischemic injury are currently unclear. In the present study, we investigated the time course of ACE2-Ang-(1-7) and Mas receptor expression in the acute stage of cerebral ischemic stroke. The content of Ang-(1-7) in ischemic tissues and blood serum was measured by specific EIA kits. Real-time PCR and western blot were used to determine messenger RNA (mRNA) and protein levels of the ACE2 and Mas. The cerebral ischemic lesion resulted in a significant increase of regional cerebral and circulating Ang-(1-7) at 6-48 h compared with sham operation group following focal ischemic stroke (12h: 7.276±0.320 ng/ml vs. 2.466±0.410 ng/ml, serum; 1.024±0.056 ng/mg vs. 0.499±0.032, brain) (P<0.05). Both ACE2 and Mas expression were markedly enhanced compared to the control in the ischemic tissues (P<0.05). Mas immunopositive neurons were also seen stronger expression in the ischemic cortex (19.167±2.858 vs. 7.833±2.483) (P<0.05). The evidence collected in our present study will indicate that, ACE2-Ang-(1-7)-Mas axis are upregulated after acute ischemic stroke and would play a pivotal role in the regulation of acute neuron injury in ischemic cerebrovascular diseases.

Blood pressure after recent stroke: baseline findings from the secondary prevention of small subcortical strokes trial

BACKGROUND

Hypertension is the most powerful risk factor for stroke. The aim of this study was to characterize baseline blood pressure in participants in the Secondary Prevention of Small Subcortical Strokes trial.

METHODS

For this cross-sectional analysis, participants were categorized by baseline systolic blood pressure (SBP) < 120, 120-139, 140-159, 160-179, and ≥ 180 mm Hg and compared on demographic and clinical characteristics. Predictors of SBP < 140 mm Hg were examined.

RESULTS

Mean SBP was 143±19 mm Hg while receiving an average of 1.7 antihypertensive medications; SBP ≥ 140 mm Hg for 53% and ≥ 160 mm Hg for 18% of the 3,020 participants. Higher SBP was associated with a history of hypertension and hypertension for longer duration (both P < 0.0001). Higher SBPs were associated with more extensive white matter disease on magnetic resonance imaging (P < 0.0001). There were significant differences in entry-level SBP when participants were categorized by race and region (both P < 0.0001). Black participants were more likely to have SBP ≥ 140 mm Hg. Multivariable logistic regression showed an independent effect for region with those from Canada more likely (odds ratio = 1.7; 95% confidence interval, 1.29, 2.32) to have SBP < 140 mm Hg compared with participants from United States.

CONCLUSIONS

In this cohort with symptomatic lacunar stroke, more than half had uncontrolled hypertension at approximately 2.5 months after stroke. Regional, racial, and clinical differences should be considered to improve control and prevent recurrent stroke.

Trials to improve blood pressure through adherence to antihypertensives in stroke/TIA: systematic review and meta-analysis

Background

The purpose of this study was to determine whether interventions including components to improve adherence to antihypertensive medications in patients after stroke/transient ischemic attack (TIA) improve adherence and blood pressure control.

Methods and Results

We searched MEDLINE, EMBASE, CINAHL, BNI, PsycINFO, and article reference lists to October 2012. Search terms included stroke/TIA, adherence/prevention, hypertension, and randomized controlled trial (RCT). Inclusion criteria were participants with stroke/TIA; interventions including a component to improve adherence to antihypertensive medications; and outcomes including blood pressure, antihypertensive adherence, or both. Two reviewers independently assessed studies to determine eligibility, validity, and quality. Seven RCTs were eligible (n=1591). Methodological quality varied. All trials tested multifactorial interventions. None targeted medication adherence alone. Six trials measured blood pressure and 3 adherence. Meta‐analysis of 6 trials showed that multifactorial programs were associated with improved blood pressure control. The difference between intervention versus control in mean improvement in systolic blood pressure was −5.3 mm Hg (95% CI, −10.2 to −0.4 mm Hg, P=0.035; I²=67% [21% to 86%]) and in diastolic blood pressure was −2.5 mm Hg (−5.0 to −0.1 mm Hg, P=0.046; I²=47% [0% to 79%]). There was no effect on medication adherence where measured.

Conclusions

Multifactorial interventions including a component to improve medication adherence can lower blood pressure after stroke/TIA. However, it is not possible to say whether or not this is achieved through better medication adherence. Trials are needed of well‐characterized interventions to improve medication adherence and clinical outcomes with measurement along the hypothesized causal pathway.