The J-curve phenomenon in stroke recurrence

Optimal blood pressure target for patients with prior stroke: A systematic review and meta-analysis

In this systematic review of randomized controlled trials, we examined the optimal blood pressure (BP) target for patients with prior stroke, comparing intensive BP control (systolic BP [SBP] <130 mmHg) with standard BP control (SBP < 140 mmHg). Literature searches of PubMed/MEDLINE, the Cochrane Database, and Ichu-shi identified seven randomized controlled trials for quantitative analysis. Meta-analyses were performed using random-effects models, with most included trials assessed as having low risks of bias. The meta-analysis showed significant reductions in recurrent stroke (risk ratio [RR], 0.79; 95% confidence interval [CI], 0.65-0.96) and major cardiovascular events (RR, 0.86; 95% CI, 0.76-0.97) in the intensive BP control arm. Intensive BP control was more effective in reducing recurrent hemorrhagic stroke (RR, 0.33; 95% CI, 0.15-0.74) than ischemic stroke (RR, 0.87; 95% CI, 0.71-1.08). However, adverse events such as syncope or dizziness were significantly more frequent in the intensive BP control arm (RR, 1.30; 95% CI, 1.00-1.68). Absolute risk reductions (per 1,000 persons) for recurrent stroke (-14; 95% CI, -24 to -4) and major cardiovascular events (-17; 95% CI, -28 to -6) outweighed the absolute increase in syncope or dizziness (4; 95% CI, 0-9). We recommend a lower SBP target of <130 mmHg, with careful monitoring for hypotension-related symptoms, to prevent recurrent stroke and major cardiovascular events in patients with prior stroke.

Real-world analysis of two ischaemic stroke and TIA systolic blood pressure goals on 12-month mortality and recurrent vascular events

INTRODUCTION

Whether obtaining the more intensive goal systolic blood pressure (SBP) of <130 mm Hg, rather than a less intensive SBP goal of <140 mm Hg poststroke/transient ischaemic attack (TIA) is associated with incremental mortality and recurrent vascular event benefit is largely unexplored using real-world data. Lowering SBP excessively may result in poorer outcomes.

METHODS

This is a retrospective cohort study of 26 368 Veterans presenting to a Veterans Administration Medical Center (VAMC) with a stroke/TIA between October 2015 and July 2018. Patients were excluded from the study if they had missing or extreme BP values, receiving dialysis or palliative care, left against medical advice had a cancer diagnosis, were cared for in a VAMC enrolled in a stroke/TIA quality improvement initiative, died or had a cerebrovascular or cardiovascular event within 90 days after their index stroke/TIA. The analytical sample included 12 337 patients. Average SBP during 90 days after discharge was assessed in categories (≤105 mm Hg, 106-115 mm Hg, 116-130 mm Hg, 131-140 mm Hg and >140 mm Hg). Separate multivariable Cox proportional hazard regressions were used to examine the relationship between average SBP groups and time to: (1) mortality and (2) any recurrent vascular event, from 90 days to up to 365 days after discharge from the index emergency department visit or inpatient admission.

RESULTS

Compared with those with SBP>140 mm Hg, patients with SBP between 116 and 130 mm Hg had a significantly lower risk of recurrent stroke/TIA (HR 0.77, 95% CI 0.60 to 0.99) but not cardiovascular events. Patients with SBP lower than 105 mm Hg, compared with those with >140 mm Hg demonstrated a statistically significant higher risk of death (HR 2.07, 95% CI 1.43 to 3.00), but no statistical differences were found in other SBP groups.

DISCUSSION

Data support a more intensive SBP goal to prevent recurrent cerebrovascular events among stroke/TIA patients by 90 days poststroke/TIA compared with less intensive goal. Very low SBPs were associated with increased mortality risk.

Acute renal intracystic hemorrhage in patients with autosomal dominant polycystic kidney disease

BACKGROUND

Renal cyst bleeding is a frequent problem in patients with autosomal dominant polycystic kidney disease (ADPKD). However, information is still limited on its frequency, causative factors, and effects on enlargement of polycystic kidneys in ADPKD.

METHODS

We investigated the total volume of acute renal intracystic hemorrhage and its association with total kidney volume (TKV) in a large series of patients with ADPKD on dialysis, referred for renal transcatheter arterial embolization. All patients had undergone CT scan and MRI scan before the procedure. We evaluated factors potentially associated with acute renal intracystic hemorrhage. The association between the  volume of acute renal intracystic hemorrhage and the potential predisposing and associated factors was analysed by univariable and multivariable regressions.  RESULTS: We enrolled 199 patients who underwent renal transcatheter arterial embolization from 2014 to 2018 (107 men, 92 women; mean age 59.1 ± 8.6 years). The median volume of acute renal intracystic hemorrhage was 97.3 ml (interquartile range 36.6-261.7 ml). Multivariable analysis revealed that body weight, kidney stones, systolic blood pressure, and total volume of acute renal intracystic hemorrhage were significantly associated with TKV; age, body mass index, smoking, renal cyst infection, serum alkaline phosphatase, and TKV were significantly associated with the volume of acute renal intracystic hemorrhage ; and sex, age, dialysis vintage, TKV, and total volume of acute renal intracystic hemorrhage were significantly associated with the number of microcoils required to achieve renal  transcatheter arterial embolization. Total volume of acute renal intracystic hemorrhage was significantly associated with TKV (r = 0.15, p = 0.0325) and was greater in younger patients (r= - 0.32, p < 0.0001). Total volume of acute renal intracystic hemorrhage was also correlated with the number of microcoils required for renal transcatheter arterial embolization (r = 0.23, p = 0.0012).

CONCLUSION

Acute renal intracystic hemorrhage is frequent among ADPKD patients on dialysis, and total volume of acute renal intracystic hemorrhage significantly associated with  TKV. Total volume of acute renal intracystic hemorrhage  was greater in younger patients with higher renal artery luminal size. These results suggest that renal cyst bleeding and renal artery blood flow may synergistically accelerate the enlargement of polycystic kidneys in ADPKD patients on dialysis.

Blood Pressure Trajectories and Outcomes for Veterans Presenting at VA Medical Centers with a Stroke or Transient Ischemic Attack

BACKGROUND

Blood pressure control has been shown to reduce risk of vascular events and mortality after an ischemic stroke or transient ischemic attack (TIA). Yet, questions remain about effectiveness, timing, and targeted blood pressure reduction.

METHODS

We analyzed data from a retrospective cohort of 18,837 veterans cared for 12 months prior and up to 12 months after an emergency department visit or inpatient admission for stroke or TIA. Latent class growth analysis was used to classify patients into systolic blood pressure trajectories. With Cox proportional hazard models, we examined relationships between blood pressure trajectories, intensification of antihypertensive medication, and stroke (fatal or non-fatal) and all-cause mortality in 12 months following the index event.

RESULTS

The cohort was classified into 4 systolic blood pressure trajectories: 19% with a low systolic blood pressure trajectory (mean systolic blood pressure = 116 mm Hg); 65% with a medium systolic blood pressure trajectory (mean systolic blood pressure = 136 mm Hg); 15% with a high systolic blood pressure trajectory (mean systolic blood pressure = 158 mm Hg), and 1% with a very high trajectory (mean systolic blood pressure = 183 mm Hg). After the stroke or TIA, individuals in the high and very high systolic blood pressure trajectories experienced a substantial decrease in systolic blood pressure that coincided with intensification of antihypertensive medication. Patients with very low and very high systolic blood pressure trajectories had a significantly greater (P < .05) hazard of mortality, while medication intensification was related significantly (P < .05) to lower hazard of mortality.

CONCLUSIONS

These findings point to the importance of monitoring blood pressure over multiple time points and of instituting enhanced hypertension management after stroke or TIA, particularly for individuals with high or very high blood pressure trajectories.

The J-Curve Association Between Blood Pressure and Mortality in Stroke Survivors

Purpose

The optimal blood pressure (BP) targets in terms of mortality risk after stroke remain unclear. This study aimed to assess the relationship between BP and mortality in stroke survivors.

Patients and Methods

We included 1696 participants with self-reported history of stroke aged 18 years and older from the National Health and Nutrition Examination Survey (NHANES) 1999–2014 and NHANES III with public-use linked mortality files from 2015. Baseline systolic BP (SBP) and diastolic BP (DBP) levels were obtained by taking the average of 3 measures. Cox proportional hazard models and restricted cubic splines were conducted to explore the relationship between BP and all-cause mortality.

Results

During a median follow-up period of 5.6 years, 888 deaths occurred. After fully adjusting for confounding factors, SBP displayed a J-curve relationship (nadir 135 mm Hg), while DBP exhibited a reverse J-curve relationship (nadir 73 mm Hg) with the risk of all-cause mortality. However, the J-curve or reverse J-curve pattern between blood pressure and mortality appeared to be limited to individuals with an age >65 years, identifying a nadir of SBP/DBP of 142/73 mm Hg. The risk of mortality followed a linear relationship for SBP and DBP in stroke survivors aged ≤65 years, with risks increasing with higher SBP and lower DBP.

Conclusion

In this cross-sectional study that used national survey data, these data suggest a strong J-curve or reverse J-curve relationship between blood pressure and risk of all-cause mortality, whereas the pattern appears to be limited to individuals with an age >65 years, with a nadir at 142/73 mmHg. However, missing data on stroke type and stroke treatment limits the generalizability. Future prospective studies are needed to determine preferential blood pressure target in patients after stroke.

Blood pressure-lowering treatment for preventing recurrent stroke, major vascular events, and dementia in patients with a history of stroke or transient ischaemic attack

BACKGROUND

Stroke is an important cause of death and disability worldwide. Since high blood pressure is an important risk factor for stroke and stroke recurrence, drugs that lower blood pressure might play an important role in secondary stroke prevention.

OBJECTIVES

To investigate whether blood pressure-lowering drugs (BPLDs) started at least 48 hours after the index event are effective for the prevention of recurrent stroke, major vascular events, and dementia in people with stroke or transient ischaemic attack (TIA). Secondary objectives were to identify subgroups of people in which BPLDs are effective, and to investigate the optimum systolic blood pressure target after stroke or TIA for preventing recurrent stroke, major vascular events, and dementia.

SEARCH METHODS

In August 2017, we searched the Trials Registers of the Cochrane Stroke Group and the Cochrane Hypertension Group, the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 8), MEDLINE Ovid (1946 to August 2017), Embase Ovid (1974 to August 2017), ClinicalTrials.gov, the ISRCTN Registry, Stroke Trials Registry, Trials Central, and the World Health Organization (WHO) International Clinical Trials Registry Platform Portal.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of BPLDs started at least 48 hours after stroke or TIA.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened all titles and abstracts, selected eligible trials, extracted the data, assessed risk of bias, and used GRADE to assess the quality of the evidence. If necessary, we contacted the principal investigators or corresponding authors for additional data.

MAIN RESULTS

We included 11 studies involving a total of 38,742 participants: eight studies compared BPLDs versus placebo or no treatment (35,110 participants), and three studies compared different systolic blood pressure targets (3632 participants). The risk of bias varied greatly between included studies. The pooled risk ratios (RRs) of BPLDs were 0.81 (95% confidence interval (CI) 0.70 to 0.93; 8 RCTs; 35,110 participants; moderate-quality evidence), 0.90 (95% CI 0.78 to 1.04; 4 RCTs; 28,630 participants; high-quality evidence) for major vascular event, and 0.88 (95% CI 0.73 to 1.06; 2 RCTs; 6671 participants; high-quality evidence) for dementia. We mainly observed a reduced risk of recurrent stroke in the subgroup of participants using an angiotensin-converting enzyme (ACE) inhibitor or a diuretic (I2 statistic for subgroup differences 72.1%; P = 0.006). The pooled RRs of intensive blood pressure-lowering were 0.80 (95% CI 0.63 to 1.00) for recurrent stroke and 0.58 (95% CI 0.23 to 1.46) for major vascular event.

AUTHORS' CONCLUSIONS

Our results support the use of BPLDs in people with stroke or TIA for reducing the risk of recurrent stroke. Current evidence is primarily derived from trials studying an ACE inhibitor or a diuretic. No definite conclusions can be drawn from current evidence regarding an optimal systolic blood pressure target after stroke or TIA.

The J-curve Association between Systolic Blood Pressure and Clinical Outcomes in Ischemic Stroke or TIA: The BOSS Study

We aimed to assess the association between systolic blood pressure (SBP) and clinical outcome in 2,397 ischemic stroke (IS) or transient ischemic attack (TIA) patients from the Blood Pressure and Clinical Outcome in TIA or Ischemic Stroke (BOSS) study. BOSS study was a hospital-based, prospective cohort study. The SBP was defined as mean value of 90 days self-measured SBP after onset. Cox proportional hazards models were conducted to test the risk of combined vascular events (CVE) and stroke recurrence among different SBP categories. Restricted cubic splines were used to explore the shape of associations between SBP and clinical outcomes. A J-shaped association of SBP with CVE and stroke recurrence within 90 days was observed (P nonlinearity < 0.001 for both). After adjusting for age, gender, medical history, atrial fibrillation, admission NHISS score, and secondary prevention. The hazard ratios (95% confidence intervals) of SBP <115 and ⩾165 mmHg compared with 125–134 mmHg were 3.45 (1.11–10.66) and 7.20 (2.91–17.80) for CVE, 2.68 (0.75–9.53) and 9.69 (3.86–24.35) for stroke recurrence, respectively. Similar J-shaped relationships were found after 1 year of follow-up. In conclusion, both high and low SBP are associated with poor prognosis in this population.

Secondary Prevention of Ischemic Cerebrovascular Disease. What Is the Evidence?

Patients who had a transient ischemic attack or stroke are at increased risk of experiencing recurrent cerebrovascular events. For this reason, secondary prevention of ischemic cerebrovascular disease is essential. Several modifiable, lifestyle-associated risk factors have been implicated, such as physical activity, smoking, and alcohol consumption. Established and emerging vascular risk factors are associated with an increased risk of stroke. Pharmacologic treatment, including the use of antiplatelet, antihypertensive, and lipid-lowering agents, has also been shown to reduce the risk of secondary cerebrovascular events. Surgical intervention, either open or endovascular, may be the preferred therapeutic option in well-defined subsets of patients. It is important to establish specific measures for the early detection and prevention of recurrent cerebrovascular disease. Therefore, further research and greater awareness in this field are needed.

The J-Curve Phenomenon in Hypertension

Almost immediately after antihypertensive therapy was proven effective in preventing cardiovascular events, the J-curve issue emerged as a hot topic. The Hypertension Optimal Treatment (HOT) trial attempted to address this question (diastolic blood pressure <80, <85, and <90 mm Hg) but ended up with a post hoc analysis indicating a nadir of 138.5 mm Hg systolic and 82.6 mm Hg diastolic blood pressure. Nevertheless, this observational finding was supported by the results of observational studies in the general population and by post hoc analyses of antihypertensive treatment trials. The currently ongoing Systolic Hypertension Optimal Treatment (SHOT) trial investigates whether the relationship between systolic blood pressure and stroke recurrence is linear or J-shaped by treating systolic blood pressure to <125, <135, and <145 mm Hg in patients with a history of recent stroke. This trial may provide additional but probably inconclusive evidence, because optimal blood pressure might differ between individuals and across outcomes. Nevertheless, a universal beneficial, instead of optimal, level of blood pressure for antihypertensive treatment may exist approximating 130/80 mm Hg and should be investigated by comparing 130/80 mm Hg with 140/90 mm Hg as a target blood pressure in hypertensive patients with the simultaneous use of modern blood pressure measuring techniques, such as home and ambulatory blood pressure monitoring.

Chronic Management of Hypertension after Stroke: The Role of Ambulatory Blood Pressure Monitoring

Hypertension is the most important potentially reversible risk factor for stroke in all age groups; high blood pressure (BP) is also associated with increased risk of recurrent stroke in patients who have already had an ischemic or hemorrhagic event. Twenty-four hour ambulatory BP monitoring (ABPM) has become an important tool for improving the diagnosis and management of hypertension, and is increasingly used to assess patients with hypertension. Nevertheless, although ABPM devices are increasingly used for assessment of hypertension, their value in the chronic management of hypertension in patients with stroke has not been systematically studied. In fact, among large-scale randomized trials for secondary stroke prevention, only the Morbidity and Mortality After Stroke, Eprosartan Compared With Nitrendipine for Secondary Prevention trial included 24-hour ABPM. ABPM has demonstrated chronic disruption of the circadian rhythm of BP after acute phase of stroke and has shown higher sensitivity compared to office BP in evaluating the effectiveness of antihypertensive treatment among stroke survivors. High 24-hour BP is an independent predictor for cerebrovascular events, brain microbleeds, and subsequent development of dementia. Nevertheless, although stroke care guidelines endorse the importance of hypertension management, the specific role of ABPM among stroke survivors after the acute phase of disease has not been established. Further studies are needed to clarify whether routine application of ABPM among these patients should be recommended.

Blood Pressure Management After Intracerebral Hemorrhage

OPINION STATEMENT

Elevated blood pressure (BP), which presents in approximately 80 % of patients with acute intracerebral hemorrhage (ICH), is associated with increased risk of poor outcome. The Second Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT2) study, a multinational, multicenter, randomized controlled trial published in 2013, demonstrated better functional outcomes with no harm for patients with acute spontaneous ICH within 6 h of onset who received target-driven, early intensive BP lowering (systolic BP target <140 mmHg within 1 h, continued for 7 days) and suggested that greater and faster reduction in BP might enhance the treatment effect by limiting hematoma growth. The trial resulted in revisions of guidelines for acute management of ICH, in which intensive BP lowering in patients with acute ICH is recommended as safe and effective treatment for improving functional outcome. BP lowering is also the only intervention that is proven to reduce the risk of recurrent ICH. Current evidences from several randomized trials, including PROGRESS and SPS3, indicate that long-term strict BP control in patients with ICH is safe and could offer additional benefits in major reduction in risk of recurrent ICH. The latest American Heart Association/American Stroke Association (AHA/ASA) guidelines recommended a target BP of <130/80 mmHg after ICH, but supporting evidence is limited. Randomized controlled trials are needed that focus on strict BP control, initiated early after onset of the disease and continued long-term, to demonstrate effective prevention of recurrent stroke and other major vascular events without additional harms in the ICH population.

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.

Use of 5-alpha-reductase inhibitors did not increase the risk of cardiovascular diseases in patients with benign prostate hyperplasia: a five-year follow-up study

Background

This nationwide population-based study investigated the risk of cardiovascular diseases after 5-alpha-reductase inhibitor therapy for benign prostate hyperplasia (BPH) using the National Health Insurance Research Database (NHIRD) in Taiwan.

Methods

In total, 1,486 adult patients newly diagnosed with BPH and who used 5-alpha-reductase inhibitors were recruited as the study cohort, along with 9,995 subjects who did not use 5-alpha-reductase inhibitors as a comparison cohort from 2003 to 2008. Each patient was monitored for 5 years, and those who subsequently had cardiovascular diseases were identified. A Cox proportional hazards model was used to compare the risk of cardiovascular diseases between the study and comparison cohorts after adjusting for possible confounding risk factors.

Results

The patients who received 5-alpha-reductase inhibitor therapy had a lower cumulative rate of cardiovascular diseases than those who did not receive 5-alpha-reductase inhibitor therapy during the 5-year follow-up period (8.4% vs. 11.2%, P=0.003). In subgroup analysis, the 5-year cardiovascular event hazard ratio (HR) was lower among the patients older than 65 years with 91 to 365 cumulative defined daily dose (cDDD) 5-alpha-reductase inhibitor use (HR=0.63, 95% confidence interval (CI) 0.42 to 0.92; P=0.018), however there was no difference among the patients with 28 to 90 and more than 365 cDDD 5-alpha-reductase inhibitor use (HR=1.14, 95% CI 0.77 to 1.68; P=0.518 and HR=0.83, 95% CI 0.57 to 1.20; P=0.310, respectively).

Conclusions

5-alpha-reductase inhibitor therapy did not increase the risk of cardiovascular events in the BPH patients in 5 years of follow-up. Further mechanistic research is needed.

Impaired perfusion modifies the relationship between blood pressure and stroke risk in major cerebral artery disease

OBJECTIVE

Blood pressure (BP) lowering may increase stroke risk in patients with symptomatic major cerebral artery disease and impaired perfusion. To investigate the relationships among BP, impaired perfusion and stroke risk.

METHODS

We retrospectively analysed data from 130 non-disabled, medically treated patients with either symptomatic extracranial carotid occlusion or intracranial stenosis or occlusion of the carotid artery or middle cerebral arteries. All patients had baseline haemodynamic measurements with (15)O-gas positron emission tomography and were followed for 2 years or until stroke recurrence or death.

RESULTS

There was a negative linear relationship between systolic BP (SBP) and risk of stroke in the territory of the diseased artery. The 2-year incidence of ischaemic stroke in the territory in patients with normal SBP (<130 mm Hg, 5/32 patients) was significantly higher than in patients with high SBP (2/98, p<0.005). Multivariate analysis revealed that normal SBP and impaired perfusion were independently associated with increased risk of stroke in the previously affected territory, while risk of stroke elsewhere was positively correlated with SBP. Overall, high total stroke risk was observed at lower BP in patients with impaired perfusion and at higher BPs in patients without (interaction, p<0.01). Overall, the relationship between SBP and total stroke recurrence was J-shaped.

CONCLUSIONS

Impaired perfusion modified the relationship between blood pressure and stroke risk, although this study had limitations including the retrospective analysis, the potentially biased sample, the small number of critical events and the fact that BP was measured only as a snapshot in clinic.

2013 ambulatory blood pressure monitoring recommendations for the diagnosis of adult hypertension, assessment of cardiovascular and other hypertension-associated risk, and attainment of therapeutic goals

Correlation between systolic (SBP) and diastolic (DBP) blood pressure (BP) level and target organ damage, cardiovascular disease (CVD) risk, and long-term prognosis is much greater for ambulatory BP monitoring (ABPM) than daytime office measurements. The 2013 ABPM guidelines specified herein are based on ABPM patient outcomes studies and constitute a substantial revision of current knowledge. The asleep SBP mean and sleep-time relative SBP decline are the most significant predictors of CVD events, both individually as well as jointly when combined with other ABPM-derived prognostic markers. Thus, they should be preferably used to diagnose hypertension and assess CVD and other associated risks. Progressive decrease by therapeutic intervention of the asleep BP mean is the most significant predictor of CVD event-free interval. The 24-h BP mean is not recommended to diagnose hypertension because it disregards the more valuable clinical information pertaining to the features of the 24-h BP pattern. Persons with the same 24-h BP mean may display radically different 24-h BP patterns, ranging from extreme-dipper to riser types, representative of markedly different risk states. Classification of individuals by comparing office with either the 24-h or awake BP mean as "masked normotensives" (elevated clinic BP but normal ABPM), which should replace the terms of "isolated office" or "white-coat hypertension", and "masked hypertensives" (normal clinic BP but elevated ABPM) is misleading and should be avoided because it disregards the clinical significance of the asleep BP mean. Outcome-based ABPM reference thresholds for men, which in the absence of compelling clinical conditions are 135/85 mmHg for the awake and 120/70 mmHg for the asleep SBP/DBP means, are lower by 10/5 mmHg for SBP/DBP in uncomplicated, low-CVD risk, women and lower by 15/10 mmHg for SBP/DBP in male and female high-risk patients, e.g., with diabetes, chronic kidney disease (CKD), and/or past CVD events. In the adult population, the combined prevalence of masked normotension and masked hypertension is >35%. Moreover, >20% of "normotensive" adults have a non-dipper BP profile and, thus, are at relatively high CVD risk. Clinic BP measurements, even if supplemented with home self-measurements, are unable to quantify 24-h BP patterning and asleep BP level, resulting in potential misclassification of up to 50% of all evaluated adults. ABPM should be viewed as the new gold standard to diagnose true hypertension, accurately assess consequent tissue/organ, maternal/fetal, and CVD risk, and individualize hypertension chronotherapy. ABPM should be a priority for persons likely to have a blunted nighttime BP decline and elevated CVD risk, i.e., those who are elderly and obese, those with secondary or resistant hypertension, and those diagnosed with diabetes, CKD, metabolic syndrome, and sleep disorders.

Current status of blood pressure management after stroke

Stroke is a leading cause of mortality and long-term disability in the western world, accounting for 5% of the UK health budget. Consequently, it has been the major focus of recent healthcare advances. Physiological disturbances are common following an acute stroke, chiefly blood pressure (BP) abnormalities (high and 'relatively' low BP), which indicate adverse prognosis. While pilot studies suggest that early intervention to moderate both extremes of BP may improve outcomes, definitive evidence is awaited from ongoing research. Long-term elevated BP is the most prevalent risk factor for future stroke, with a comprehensive evidence base supporting BP reduction to reduce the risk of vascular events, including stroke. However, adherence to secondary preventive medications, including antihypertensive agents, remains poor. This article summarizes the current understanding of the role of BP in stroke, focusing on the management of BP for secondary prevention. Further emphasis is placed on identifying deficiencies in long-term management; barriers to improved application and potential interventions to overcome these barriers are summarized.

Blood pressure-lowering treatment for primary and secondary prevention of different types of stroke

High blood pressure is the most important modifiable risk factor for stroke and accumulating evidence indicates that blood pressure levels are likely to be associated with all stroke subtypes. There is also evidence from randomized trials suggesting that blood pressure-lowering treatment provides protection against every stroke subtype in both primary and secondary prevention settings. Blood pressure lowering is likely to be one of the most effective and generalizable strategies across a variety of stroke subtypes.

Cardiovascular comorbidities and blood pressure control in stroke survivors

OBJECTIVE

To examine the association of cardiovascular(CV) comorbidities with the likelihood of being a stroke survivor and to determine the prevalence, treatment, and control of hypertension in this population.

METHODS

In the National Health and Nutrition Examination Survey from 1999 to 2004, 495 stroke survivors, aged 20 years or older, were characterized by CV risk factors and comorbidities. Hypertension prevalence, treatment,and control rates were determined and logistic regression was performed to examine the likelihood of stroke according to the presence of comorbidities.

RESULTS

Of the stroke survivors, 59.4% were women, 57.1%were at least 65 years of age, 66.2% were overweight/obese, 25.1% were current smokers, 75.1% had hypertension, and 79.3% had additional comorbidities,including diabetes mellitus (24.7%), coronary artery disease(28.8%), chronic kidney disease (25.3%), heart failure(16.5%), and peripheral arterial disease (10.9%). The odds(and 95% confidence intervals) of prevalent stroke were 2.2(1.5-3.2), 5.0 (3.2-7.8), 4.1 (2.1-7.8), and 10.0 (4.8-20.9)with one, two, three, and four or more comorbidities,respectively. Of these high-risk stroke survivors with comorbidities and hypertension, 18% were not receiving antihypertensive therapy; of those receiving therapy, 55.3%did not meet a systolic blood pressure goal of less than 140 mmHg and, on average, were 20 mmHg above this target.

CONCLUSION

A high percentage of stroke survivors,projected to 4.98 million adults in the USA have multiple CV risk factors, numerous comorbidities, and poor control of hypertension, placing them at increased risk for further complications. Therefore, increased efforts must be made to reduce overall global risk in these high-risk persons.

Comparison of the anti-hypertensive effects of the L/N-type calcium channel antagonist cilnidipine, and the L-type calcium channel antagonist amlodipine in hypertensive patients with cerebrovascular disease

OBJECTIVES

It is known that the risk of cerebral stroke recurrence in post-stroke patients is comparatively higher than in normal subjects, and it is suggested that autonomic nervous system dysfunctions elevate this risk. We investigated the anti-hypertensive effects of cilnidipine, a Ca antagonist which suppresses sympathetic nerve activation, in hypertensives with chronic-stage cerebrovascular disease in a comparison with amlodipine.

METHODS

Amlodipine 5-7.5 mg/day, or cilnidipine 5-10 mg/day was administered to 78 hypertensive subjects (greater than 140 mmHg systolic, or 90 mmHg diastolic) undergoing outpatient treatment. Amlodipine or cilnidipine was also administered similarly, to 30 subjects having hypertension associated with a cerebral infarct which occurred more than one month earlier due to cerebral thrombosis or embolism. After 3 months administration, the subjects' blood pressures and pulse rates were recorded with an ambulatory blood pressure monitor over 24 hours.

RESULTS

No difference was recognized in patient age, gender, and systolic and diastolic blood pressure before treatment between the groups. In the cilnidipine groups, no difference in average 24-hour or waking systolic blood pressure values was seen between cerebrovascular disease (CVD) subjects and non-CVD subjects, although in the amlodipine groups, CVD subjects had significantly higher blood pressure values than non-CVD subjects. In the cilnidipine group, the coefficient of variation values of pulse rate were significantly higher in CVD subjects than in non-CVD subjects (p<0.05).

CONCLUSION

In patients with recent stroke, a Ca antagonist with no sympathetic nerve suppression had weaker blood pressure-lowering effects. Significantly increased pulse rate variability, shown in the CVD subjects administered cilnidipine, suggests that cilnidipine enhanced the parasympathetic function in hypertensive patients with CVD.

Review: Recurrent stroke: where do we stand with the secondary prevention of noncardioembolic ischaemic strokes?

Strokes recur in 6—20% of the patients, most commonly within the first year; after a TIA or minor stroke; most recurrences will occur within the first 90 days. Our ability to identify patients at high risk is poor and most recurrent strokes cannot be explained by traditional risk factors. In 30—45% of the cases the second stroke will be of a different subtype. Moreover, patients are faced with other risks, like cardiac events and cognitive decline. With the population aging, the need for timely and effective secondary prevention strategies is more pressing than ever. This paper summarizes recent advances in pharmacological secondary prevention after a non-cardioembolic ischaemic stroke, and highlights critical questions still in need of answers.

Recurrent stroke: the role of common carotid artery intima-media thickness

The etiology of recurrent stroke is probably multifactorial and many recurrences remain unexplained by conventional risk factors. The purpose of this study is to investigate if common carotid artery intima-media thickness (CCA-IMT), an established vascular risk factor, can predict recurrence in first-ever stroke survivors. Two hundred and eighty-four consecutive patients with a first-ever ischemic stroke were investigated with carotid ultrasonography and were screened for the first recurrent stroke up to 12 months. Sixteen (5.6%, 95% CI: 3.5-9.0%) recurrent ischemic strokes were recorded. Among demographic data, conventional vascular risk factors, presenting stroke features and ultrasonographic measurements, CCA-IMT was the only parameter that differed significantly between those who suffered a recurrent stroke and those who did not. Cox's regression analysis adjusted for confounding factors, showed that CCA-IMT was the only independent predictor of stroke recurrence (HR 1.65; 95% CI: 1.11-2.46%). We propose that CCA-IMT measurements may help to identify stroke patients at higher risk for recurrence and to plan secondary prevention strategies.

Cerebral perfusion in the elderly with nocturnal blood pressure fall

Cerebrovascular disease may be linked with vascular autoregulation in aging. The aim of this study was to examine relation between nocturnal blood pressure (BP) fall and cerebral blood flow (CBF) changes in elderly men. The prospective 'Men born in 1914' cohort study has been in progress since 1968 and included 809 subjects. After 14 years from the last follow up, 97 subjects reached the age of 82 and underwent CBF measurement and 24 h ambulatory blood pressure monitoring. Diastolic BP at night decreased in 84 subjects with median 12.7% and increased in 13 subjects with median 3.7%. Relative diastolic BP fall at night was negatively associated to CBF in temporal and infero-parietal areas. Higher proportion of subjects with increasing systolic BP during the 14-year period was observed in the subgroup with extreme nocturnal diastolic BP dip, irrespectively of BP values or prevalence of hypertension. Extreme nocturnal diastolic BP fall in a cohort of elderly men is correlated with focal changes in CBF. Further studies could explain if increasing BP in the elderly is a cause or result of pathological autoregulation, and if antihypertensive treatment increases nocturnal BP dip.

The Management of Blood Pressure After Stroke

BACKGROUND

Control of hypertension is a well-established goal of primary prevention of stroke, but management of blood pressure in patients with a previous stroke or in the setting of acute stroke is complicated by the effect blood pressure changes may have on cerebral perfusion.

REVIEW SUMMARY

For patients with previous transient ischemic attack or chronic stroke, blood pressure reduction appears to be a safe and important facet of the secondary prevention of recurrent stroke. Less information is available concerning blood pressure management in acute stroke. Current protocols require strict blood pressure control in patients who are treated with thrombolytic therapy, to reduce the risk of hemorrhagic complications. In patients presenting with acute intracerebral hemorrhage, blood pressure reduction does not appear to cause significant reduction of cerebral blood flow, but at this time there are no studies to determine if there is a clinical benefit of acute blood pressure reduction in these patients. Finally, blood pressure reduction is not routinely recommended in patients with acute ischemic stroke, as it may precipitate further cerebral ischemia. Preliminary studies suggest, in fact, that there may be a role in the future for blood pressure elevation in the treatment of patients with acute ischemic stroke.

CONCLUSIONS

Current data support the use of blood pressure reduction in the secondary prevention of stroke in patients with cerebrovascular disease. In the setting of acute stroke, however, data are limited and blood pressure management must be tailored to the specific clinical situation.

The challenge of blood pressure management in neurologic emergencies

Hypertensive crises are commonly seen in the emergency department, and acute stroke is often the inciting etiology of a hypertensive crisis. Cerebral autoregulation is disrupted in acute stroke, and efforts to lower blood pressure may reduce cerebral perfusion and worsen outcomes. Although most patients with stroke have elevated blood pressure, evidence from clinical trials to guide therapy are scarce. Current national guidelines recommend lowering blood pressure after stroke only if end-organ damage is present or if systolic/diastolic blood pressures exceed 220/120 or 185/110 mm Hg in patients ineligible and in those eligible to receive thrombolytic drug therapy, respectively. Recommended pharmacologic interventions for elevated blood pressure after acute ischemic stroke include labetalol, nicardipine, or nitroprusside, depending on the severity of the elevation. Similar recommendations have been made for intracerebral hemorrhage. Subarachnoid hemorrhage is managed with nimodipine and other calcium channel blockers to prevent vasospasm and improve clinical outcomes. Data from ongoing clinical trials may improve guidance about the management of elevated blood pressure after acute stroke.

Blood Pressure Level and Outcomes in Adults Aged 65 and Older with Prior Ischemic Stroke

OBJECTIVES

To examine the association between blood pressure (BP) levels and long-term stroke outcomes in elderly stroke survivors.

DESIGN

Observational study.

SETTING

The Cardiovascular Health Study (CHS) of 5,888 community-dwelling adults.

PARTICIPANTS

Two hundred fifty-four adults aged 65 and older (mean age 78.6) who sustained a nonfatal first ischemic stroke.

MEASUREMENTS

BP levels assessed at prestroke and poststroke CHS visits were examined as predictors of stroke recurrence, coronary heart disease (CHD), combined vascular events (CVEs), and mortality.

RESULTS

Higher poststroke BP level, assessed 261.6 days (mean) after stroke, was associated with higher risk of stroke recurrence over 5.4 years (mean) of follow-up. The multivariate-adjusted hazard ratio for stroke recurrence was 1.42 (95% confidence interval (CI) = 1.03-1.99) per standard deviation (SD) of systolic BP (P = .04) and 1.39 (95% CI = 1.01-1.91) per SD of diastolic BP (P = .04). Mortality was significantly greater in patients with low or high poststroke BP than in those with intermediate BP. Poststroke BP was not associated with risk of CHD or CVE, although further analyses suggested that high systolic BP predicted CHD and CVE in younger but not older subjects. Prestroke BP did not predict poststroke outcomes.

CONCLUSION

In this observational study of adults aged 65 and older assessed approximately 8 months after stroke, low BP was associated with favorable risk of recurrent stroke, although high and low poststroke BP levels were associated with greater mortality. Long-term antihypertensive trials in older stroke survivors would increase knowledge about the benefits of lowering BP in this population.

Secondary prevention of stroke by blood pressure-lowering treatment

High blood pressure is the most important modifiable risk factor for stroke, accounting for more than 50% of the population-attributable fraction for stroke. There is now strong evidence from randomized trials that blood pressure-lowering treatment is one of the most effective and generalizable strategies for secondary prevention of stroke. Once the patient with stroke has stabilized, all patients should receive blood pressure-lowering therapy, irrespective of their blood pressure levels. Combination therapy with an angiotensin-converting enzyme (ACE) inhibitor plus a diuretic is an established regimen, but an angiotensin II-receptor blocker may provide an alternative regimen in patients who do not tolerate an ACE inhibitor, especially in combination with a diuretic. For patients with previous stroke, goal blood pressures of < 130/80 mm Hg in hypertensive subjects and < 120/80 mm Hg in normotensive (or "prehypertensive") subjects should be achieved using combination blood pressure-lowering therapy.

Lower target blood pressures are safe and effective for the prevention of recurrent stroke: the PROGRESS trial

OBJECTIVE

To explore the likely optimum blood pressure (BP) level for patients with a history of cerebrovascular disease.

METHODS

The Perindopril Protection Against Recurrent Stroke Study (PROGRESS) was a randomized, placebo-controlled trial that established the beneficial effects of BP lowering in 6105 patients with cerebrovascular disease. The present study comprises two series of post hoc analyses. The first was designed to investigate the effects of randomized treatment on recurrent stroke by baseline BP levels, and the second was a corresponding observational analysis investigating the association between achieved follow-up BP levels and recurrent stroke risk.

RESULTS

Analyses of the randomized treatment comparisons showed that BP lowering with combination therapy produced similar risk reductions in each of four subgroups defined by baseline BP of less than 120, 120-139, 140-159, and 160 mmHg or greater (P homogeneity = 0.5). The effects of single-drug therapy were also comparable across these subgroups (P homogeneity = 0.2), but consistently greater benefits were observed with combination compared to single-drug therapy. The analyses of achieved follow-up BP showed that the lowest risk of recurrence was among the one-quarter of participants with the lowest follow-up BP levels (median 112/72 mmHg), and that risks rose progressively with higher follow-up BP levels. Minor side-effects were progressively more common at lower BP levels (P homogeneity = 0.04), but there was no excess of serious complications (all P homogeneity > 0.2).

CONCLUSION

These analyses provide no evidence of a J-curve relationship between BP level and stroke risk among patients with cerebrovascular disease, and identify no patient group among whom more intensive BP lowering would not be expected to produce greater risk reductions.

Diastolic blood pressure influences cerebrovascular reactivity measured by means of123I-iodoamphetamine brain single photon emission computed tomography in medically treated patients with occlusive carotid or middle cerebral artery disease

OBJECTIVE

Impaired cerebrovascular reactivity (CVR) to vasodilating agents is a predictor of the onset and prognosis of ischemic stroke. It is realized that the CVR improves or worsens when measured periodically during the clinical course in medically treated patients with occlusive cerebrovascular disease. In these patients, we investigated the possible relationship between the interval change in CVR and that in systemic blood pressure (BP).

METHODS

Forty-two patients (14 females and 28 males, mean age +/- SD: 65.3 +/- 8.8 years) with severe stenosis or occlusion of the common carotid, internal carotid, or middle cerebral arteries repeatedly underwent single photon emission computed tomography (SPECT) studies using 123I-iodoamphetamine to measure cerebral blood flow (CBF) distribution and CVR at a more-than-6-month interval (mean +/- SD: 18.5 +/- 8.8 months). The CVR was separately estimated in cerebral hemispheres ipsilateral and contralateral to the most severe vascular lesion as the % increase in CBF after acetazolamide loading to CBF at rest. Systemic BP was measured four times at enrollment and the follow-up SPECT studies during resting and acetazolamide loading. Average BP at each SPECT study was an average of BP measurements during resting and acetazolamide loading. Interval changes in CVR were correlated with those in average systolic BP, average diastolic BP, and average mean arterial BP.

RESULTS

The interval changes in CVR were significantly correlated with those in average diastolic BP in the ipsilateral hemisphere (y = 0.71x + 1.43, r2 = 0.11, p < 0.05) and in the contralateral hemisphere (y = 0.88x - 0.46, r2 = 0.16, p < 0.05) but not with those in average systolic BP or average mean arterial BP.

CONCLUSIONS

In medically treated patients with steno-occlusive carotid artery or middle cerebral artery lesions, the interval change in CVR to acetazolamide by means of 123I-IMP SPECT was influenced by the diastolic BP at the SPECT studies. Monitoring diastolic BP is important to evaluate interval change in CVR.

Blood Pressure as a Risk Factor for Stroke and the Impact of Antihypertensive Treatment

We review hypertension and blood pressure levels as risk factors for stroke and the impact of antihypertensive treatment on the prevention of first stroke event and of recurrent stroke, not only with respect to the prevention of vascular events but also the prevention of cognitive deterioration, dementia, and physical disability. We review whether pharmacological blockage of the renin-angiotensin system has additional long-term effects over that of control of blood pressure levels alone, and the benefit of treatment with antihypertensive drugs in normotensive patients. Therapeutic objectives for blood pressure levels after stroke are defined together with recommendations of drugs and doses which have been demonstrated to have the greatest benefit in the prevention of stroke.

Blood Pressure Control in Hypertensive Patients With a History of Stroke

The targets for lowering blood pressure (BP) in hypertensive stroke patients remain unclear. We assessed the current status of BP control in hypertensive patients with a history of stroke, investigating 413 hypertensive patients (age range, 19 to 93; mean age, 62 +/- 12 years) who visited the hypertension and stroke clinic at Kyushu University Hospital. We compared the clinical characteristics of these hypertensive patients with a history of stroke, including brain infarction, transient ischemic attack, and brain hemorrhage (age range, 29-86; mean age, 66 +/- 12 years; n = 95) with those of patients without such a history (age range, 19-93; mean age, 61 +/- 12 years; n = 318). Clinic BP was measured by physicians with a mercury sphygmomanometer, and the averaged BP determined at 2 occasions in 2002 was used for analysis. Systolic BP was similar among the patients with and without a history of stroke (134 +/- 15 vs 137 +/- 14 mm Hg; P = not significant), but diastolic BP was significantly lower in patients with stroke than in those without stroke (76 +/- 10 vs 82 +/- 10 mm Hg; P < .05). When strict BP control was defined as <130/85 mm Hg, the rate of strict BP control was higher in the stroke patients than in those without stroke (35.8% vs 19.8%; P < .01). The average number of antihypertensive drug classes used was similar in the 2 groups (1.7 +/- 0.9 and 1.8 +/- 1.0, respectively). Calcium antagonists were the most frequently used drugs in both groups. Diuretics and beta-blockers were prescribed less frequently to the patient with ischemic stroke than to those without stroke. BP levels were lower in the patients with brain hemorrhage than in those with lacunar and atherothrombotic infarction. In our outpatient clinic, BP levels were lower in the stroke patients than in the patients without stroke, which may reflect physicians' awareness of the importance of strict BP control in stroke patients, as has been suggested by several recent clinical intervention trials.