Acute post-stroke blood pressure relative to premorbid levels in intracerebral haemorrhage versus major ischaemic stroke: a population-based study.

BACKGROUND It is often assumed that blood pressure increases acutely after major stroke, resulting in so-called post-stroke hypertension. In view of evidence that the risks and benefits of blood pressure-lowering treatment in acute stroke might differ between patients with major ischaemic stroke and those with primary intracerebral haemorrhage, we compared acute-phase and premorbid blood pressure levels in these two disorders. METHODS In a population-based study in Oxfordshire, UK, we recruited all patients presenting with stroke between April 1, 2002, and March 31, 2012. We compared all acute-phase post-event blood pressure readings with premorbid readings from 10-year primary care records in all patients with acute major ischaemic stroke (National Institutes of Health Stroke Scale >3) versus those with acute intracerebral haemorrhage. FINDINGS Of 653 consecutive eligible patients, premorbid and acute-phase blood pressure readings were available for 636 (97%) individuals. Premorbid blood pressure (total readings 13,244) had been measured on a median of 17 separate occasions per patient (IQR 8-31). In patients with ischaemic stroke, the first acute-phase systolic blood pressure was much lower than after intracerebral haemorrhage (158·5 mm Hg [SD 30·1] vs 189·8 mm Hg [38·5], p<0·0001; for patients not on antihypertensive treatment 159·2 mm Hg [27·8] vs 193·4 mm Hg [37·4], p<0·0001), was little higher than premorbid levels (increase of 10·6 mm Hg vs 10-year mean premorbid level), and decreased only slightly during the first 24 h (mean decrease from <90 min to 24 h 13·6 mm Hg). By contrast with findings in ischaemic stroke, the mean first systolic blood pressure after intracerebral haemorrhage was substantially higher than premorbid levels (mean increase of 40·7 mm Hg, p<0·0001) and fell substantially in the first 24 h (mean decrease of 41·1 mm Hg; p=0·0007 for difference from decrease in ischaemic stroke). Mean systolic blood pressure also increased steeply in the days and weeks before intracerebral haemorrhage (regression p<0·0001) but not before ischaemic stroke. Consequently, the first acute-phase blood pressure reading after primary intracerebral haemorrhage was more likely than after ischaemic stroke to be the highest ever recorded (OR 3·4, 95% CI 2·3-5·2, p<0·0001). In patients with intracerebral haemorrhage seen within 90 min, the highest systolic blood pressure within 3 h of onset was 50 mm Hg higher, on average, than the maximum premorbid level whereas that after ischaemic stroke was 5·2 mm Hg lower (p<0·0001). INTERPRETATION Our findings suggest that systolic blood pressure is substantially raised compared with usual premorbid levels after intracerebral haemorrhage, whereas acute-phase systolic blood pressure after major ischaemic stroke is much closer to the accustomed long-term premorbid level, providing a potential explanation for why the risks and benefits of lowering blood pressure acutely after stroke might be expected to differ. FUNDING Wellcome Trust, Wolfson Foundation, UK Medical Research Council, Stroke Association, British Heart Foundation, National Institute for Health Research.

Associations Between Cardiovascular Risk Factors, Inflammation, and Progression of Carotid Atherosclerosis Among Smokers

INTRODUCTION The high risk of cardiovascular events in smokers requires adequate control of other cardiovascular risk factors (CVRFs) to curtail atherosclerosis progression. However, it is unclear which CVRFs have the most influence on atherosclerosis progression in smokers. METHODS In 260 smokers aged 40-70 included in a smoking cessation trial, we analyzed the association between traditional CVRFs, high-sensitivity C-reactive protein (hs-CRP), smoking cessation and 3-year progression of carotid intima-media thickness (CIMT, assessed by repeated ultrasound measurements) in a longitudinal multivariate model. RESULTS Participants (mean age 52 years, 47% women) had a mean smoking duration of 32 years with a median daily consumption of 20 cigarettes. Baseline CIMT was 1185 μm (95% confidence interval [CI]: 1082-1287) and increased by 93 μm (95% CI: 25-161) and 108 μm (95% CI: 33-183) after 1 and 3 years, respectively. Age, male sex, daily cigarette consumption, systolic blood pressure (SBP), but neither low-density lipoprotein cholesterol nor hs-CRP, were independently associated with baseline CIMT (all P ≤ .05). Baseline SBP, but neither low-density lipoprotein cholesterol nor hs-CRP, was associated with 3-year atherosclerosis progression (P = .01 at 3 years). The higher the SBP at baseline, the steeper was the CIMT increase over 3-year follow-up. We found an increase of 26 μm per each 10-mmHg raise in SBP at 1 year and an increase of 39 μm per each 10 mmHg raise in SBP at 3 years. Due to insufficient statistical power, we could not exclude an effect of smoking abstinence on CIMT progression. CONCLUSION Control of blood pressure may be an important factor to limit atherosclerosis progression in smokers, besides support for smoking cessation. IMPLICATIONS Among 260 smokers aged 40-70 years with a mean smoking duration of 32 years, baseline SBP was associated with atherosclerosis progression over 3 years, as measured by CIMT (P = .01 at 3 years), independently of smoking variables and other CVRFs. The higher the SBP at baseline, the steeper was the CIMT increase over 3-year follow-up. Our findings emphasize the importance of focusing not only on smoking cessation among smokers, but to simultaneously control other CVRFs, particularly blood pressure, in order to prevent future cardiovascular disease.

Closed-loop control of mean arterial blood pressure during surgery with alfentanil: clinical evaluation of a novel model-based predictive controller

BACKGROUND: In contrast to hypnosis, there is no surrogate parameter for analgesia in anesthetized patients. Opioids are titrated to suppress blood pressure response to noxious stimulation. The authors evaluated a novel model predictive controller for closed-loop administration of alfentanil using mean arterial blood pressure and predicted plasma alfentanil concentration (Cp Alf) as input parameters. METHODS: The authors studied 13 healthy patients scheduled to undergo minor lumbar and cervical spine surgery. After induction with propofol, alfentanil, and mivacurium and tracheal intubation, isoflurane was titrated to maintain the Bispectral Index at 55 (+/- 5), and the alfentanil administration was switched from manual to closed-loop control. The controller adjusted the alfentanil infusion rate to maintain the mean arterial blood pressure near the set-point (70 mmHg) while minimizing the Cp Alf toward the set-point plasma alfentanil concentration (Cp Alfref) (100 ng/ml). RESULTS: Two patients were excluded because of loss of arterial pressure signal and protocol violation. The alfentanil infusion was closed-loop controlled for a mean (SD) of 98.9 (1.5)% of presurgery time and 95.5 (4.3)% of surgery time. The mean (SD) end-tidal isoflurane concentrations were 0.78 (0.1) and 0.86 (0.1) vol%, the Cp Alf values were 122 (35) and 181 (58) ng/ml, and the Bispectral Index values were 51 (9) and 52 (4) before surgery and during surgery, respectively. The mean (SD) absolute deviations of mean arterial blood pressure were 7.6 (2.6) and 10.0 (4.2) mmHg (P = 0.262), and the median performance error, median absolute performance error, and wobble were 4.2 (6.2) and 8.8 (9.4)% (P = 0.002), 7.9 (3.8) and 11.8 (6.3)% (P = 0.129), and 14.5 (8.4) and 5.7 (1.2)% (P = 0.002) before surgery and during surgery, respectively. A post hoc simulation showed that the Cp Alfref decreased the predicted Cp Alf compared with mean arterial blood pressure alone. CONCLUSION: The authors' controller has a similar set-point precision as previous hypnotic controllers and provides adequate alfentanil dosing during surgery. It may help to standardize opioid dosing in research and may be a further step toward a multiple input-multiple output controller.

Risk of Cardiovascular Events and Blood Pressure Control in Hypertensive HIV-Infected Patients: HIV Cohort Study (SHCS)

Background: Prevalence of hypertension in HIV infection is high, and information on blood pressure control in HIV-infected individuals is insufficient. We modeled blood pressure over time and the risk of cardiovascular events in hypertensive HIV-infected individuals. Methods: All patients from the Swiss HIV Cohort Study with confirmed hypertension (systolic or diastolic blood pressure above 139 or 89 mm Hg on 2 consecutive visits and presence of at least 1 additional cardiovascular risk factor) between April 1, 2000 and March 31, 2011 were included. Patients with previous cardiovascular events, already on antihypertensive drugs, and pregnant women were excluded. Change in blood pressure over time was modeled using linear mixed models with repeated measurement. Results: Hypertension was diagnosed in 2595 of 10,361 eligible patients. Of those, 869 initiated antihypertensive treatment. For patients treated for hypertension, we found a mean (95% confidence interval) decrease in systolic and diastolic blood pressure of −0.82 (−1.06 to −0.58) mm Hg and −0.89 (−1.05 to −0.73) mm Hg/yr, respectively. Factors associated with a decline in systolic blood pressure were baseline blood pressure, presence of chronic kidney disease, cardiovascular events, and the typical risk factors for cardiovascular disease. In patients with hypertension, increase in systolic blood pressure [(hazard ratio 1.18 (1.06 to 1.32) per 10 mm Hg increase], total cholesterol, smoking, age, and cumulative exposure to protease inhibitor–based and triple nucleoside regimens were associated with cardiovascular events. Conclusions: Insufficient control of hypertension was associated with increased risk of cardiovascular events indicating the need for improved management of hypertension in HIV-infected individuals.

Hypercoagulation and hyperkinetic blood pressure indicative of physiological loss-of-control despite behavioural control in Africans: The SABPA study.

OBJECTIVES A dissociation between behavioural (in-control) and physiological parameters (indicating loss-of-control) is associated with cardiovascular risk in defensive coping (DefS) Africans. We evaluated relationships between DefS, sub-clinical atherosclerosis, low-grade inflammation and hypercoagulation in a bi-ethnic sex cohort. METHODS Black (Africans) and white Africans (Caucasians) (n = 375; aged 44.6 ± 9.7 years) were included. Ambulatory BP, vascular structure (left carotid cross-sectional wall area (L-CSWA) and plaque counts), and markers of coagulation and inflammation were quantified. Ethnicity/coping style interaction was revealed only in DefS participants. RESULTS A hypertensive state, less plaque, low-grade inflammation, and hypercoagulation were more prevalent in DefS Africans (27-84%) than DefS Caucasians (18-41%). Regression analyses demonstrated associations between L-CSWA and 24 hour systolic BP (R(2) = 0.38; β = 0.78; p < 0.05) in DefS African men but not in DefS African women or Caucasians. No associations between L-CSWA and coagulation markers were evident. CONCLUSION Novel findings revealed hypercoagulation, low-grade inflammation and hyperkinetic BP (physiological loss-of-control responses) in DefS African men. Coupled to a self-reported in-control DefS behavioural profile, this reflects dissociation between behaviour and physiology. It may explain changes in vascular structure, increasing cerebrovascular disease risk in a state of hyper-vigilant coping.

Neural correlates of disbalanced motor control in major depression

Motor retardation is a common symptom of major depressive disorder (MDD). Despite the existence of various assessment methods, little is known on the pathobiology of motor retardation. We aimed to elucidate aspects of motor control investigating the association of objective motor activity and resting state cerebral blood flow (CBF).

[Drug-independent blood pressure control through the autonomous nervous system]

Arterial hypertension is a chronic disease with a therapeutical challenge for the patient and the physician involved. Patient-independent techniques with good efficacy and tolerability are wanted. The autonomous nervous system insufficiently therapeutically exploited to date, is now approachable by two types of intervention: renal nerve ablation, an endovascular approach without remaining foreign body, and BAT, baroreflex activating therapy using an implantable device stimulating the carotid sinus. The blood pressure lowering potency of BAT appears more than with renal nerve ablation and also clinical study data are more prevalent. With both treatment options the patients having the most profit are insufficiently defined. Given this knowledge, any form of secondary hypertension needs to be excluded beforehand.

Early autonomic dysfunction in patients with diabetes mellitus assessed by spectral analysis of heart rate and blood pressure variability

Patients with diabetes mellitus (DM) often have alterations of the autonomic nervous system (ANS), even early in their disease course. Previous research has not evaluated whether these changes may have consequences on adaptation mechanisms in DM, e.g. to mental stress. We therefore evaluated whether patients with DM who already had early alterations of the ANS reacted with an abnormal regulatory pattern to mental stress. We used the spectral analysis technique, known to be valuable and reliable in the investigation of disturbances of the ANS. We investigated 34 patients with DM without clinical evidence of ANS dysfunction (e.g. orthostatic hypotension) and 44 normal control subjects (NC group). No patients on medication known to alter ANS responses were accepted. The investigation consisted of a resting state evaluation and a mental stress task (BonnDet). In basal values, only the 21 patients with type 2 DM were different in respect to body mass index and systolic blood pressure. In the study parameters we found significantly lower values in resting and mental stress spectral power of mid-frequency band (known to represent predominantly sympathetic influences) and of high-frequency and respiration bands (known to represent parasympathetic influences) in patients with DM (types 1 and 2) compared with NC group (5.3 +/- 1.2 ms2 vs. 6.1 +/- 1.3 ms2, and 5.5 +/- 1.6 ms2 vs. 6.2 +/- 1.5 ms2, and 4.6 +/- 1.7 ms2 vs. 6.2 +/- 1.5 ms2, for resting values respectively; 4.7 +/- 1.4 ms2 vs. 5.9 +/- 1.2 ms2, and 4.6 +/- 1.9 ms2 vs. 5.6 +/- 1.7 ms2, and 3.7 +/- 2.1 ms2 vs. 5.6 +/- 1.7 ms2, for stress values respectively; M/F ratio 6/26 vs. 30/14). These differences remained significant even when controlled for age, sex, and body weight. However, patients with DM type 2 (and significantly higher body weight) showed only significant values in mental stress modulus values. There were no specific group effects in the patients with DM in adaptation mechanisms to mental stress compared with the NC group. These findings demonstrate that power spectral examinations at rest are sufficiently reliable to diagnose early alterations in ANS in patients with DM. The spectral analysis technique is sensitive and reliable in investigation of ANS in patients with DM without clinically symptomatic autonomic dysfunction.

Association of arterial blood pressure and vasopressor load with septic shock mortality: a post hoc analysis of a multicenter trial

INTRODUCTION: It is unclear to which level mean arterial blood pressure (MAP) should be increased during septic shock in order to improve outcome. In this study we investigated the association between MAP values of 70 mmHg or higher, vasopressor load, 28-day mortality and disease-related events in septic shock. METHODS: This is a post hoc analysis of data of the control group of a multicenter trial and includes 290 septic shock patients in whom a mean MAP > or = 70 mmHg could be maintained during shock. Demographic and clinical data, MAP, vasopressor requirements during the shock period, disease-related events and 28-day mortality were documented. Logistic regression models adjusted for the geographic region of the study center, age, presence of chronic arterial hypertension, simplified acute physiology score (SAPS) II and the mean vasopressor load during the shock period was calculated to investigate the association between MAP or MAP quartiles > or = 70 mmHg and mortality or the frequency and occurrence of disease-related events. RESULTS: There was no association between MAP or MAP quartiles and mortality or the occurrence of disease-related events. These associations were not influenced by age or pre-existent arterial hypertension (all P > 0.05). The mean vasopressor load was associated with mortality (relative risk (RR), 1.83; confidence interval (CI) 95%, 1.4-2.38; P < 0.001), the number of disease-related events (P < 0.001) and the occurrence of acute circulatory failure (RR, 1.64; CI 95%, 1.28-2.11; P < 0.001), metabolic acidosis (RR, 1.79; CI 95%, 1.38-2.32; P < 0.001), renal failure (RR, 1.49; CI 95%, 1.17-1.89; P = 0.001) and thrombocytopenia (RR, 1.33; CI 95%, 1.06-1.68; P = 0.01). CONCLUSIONS: MAP levels of 70 mmHg or higher do not appear to be associated with improved survival in septic shock. Elevating MAP >70 mmHg by augmenting vasopressor dosages may increase mortality. Future trials are needed to identify the lowest acceptable MAP level to ensure tissue perfusion and avoid unnecessary high catecholamine infusions.

500 ml of blood loss does not decrease non-invasive tissue oxygen saturation (StO2) as measured by near infrared spectroscopy - A hypothesis generating pilot study in healthy adult women

Background The goal when resuscitating trauma patients is to achieve adequate tissue perfusion. One parameter of tissue perfusion is tissue oxygen saturation (StO2), as measured by near infrared spectroscopy. Using a commercially available device, we investigated whether clinically relevant blood loss of 500 ml in healthy volunteers can be detected by changes in StO2 after a standardized ischemic event. Methods We performed occlusion of the brachial artery for 3 minutes in 20 healthy female blood donors before and after blood donation. StO2 and total oxygenated tissue hemoglobin (O2Hb) were measured continuously at the thenar eminence. 10 healthy volunteers were assessed in the same way, to examine whether repeated vascular occlusion without blood donation exhibits time dependent effects. Results Blood donation caused a substantial decrease in systolic blood pressure, but did not affect resting StO2 and O2Hb values. No changes were measured in the blood donor group in the reaction to the vascular occlusion test, but in the control group there was an increase in the O2Hb rate of recovery during the reperfusion phase. Conclusion StO2 measured at the thenar eminence seems to be insensitive to blood loss of 500 ml in this setting. Probably blood loss greater than this might lead to detectable changes guiding the treating physician. The exact cut off for detectable changes and the time effect on repeated vascular occlusion tests should be explored further. Until now no such data exist.

Effects of {beta}-blocker selectivity on blood pressure variability and stroke: A systematic review

β-Blockers increase variability in systolic blood pressure (SBP), which probably explains their lesser effectiveness in preventing stroke vs myocardial infarction compared with other agents. This increase in variability in blood pressure (BP) may be particularly marked on non-cardioselective agents, potentially calling into question the widespread first-line use of propranolol in migraine with aura, elderly patients with essential tremor or anxiety, and other groups at risk of stroke.

Effects of antihypertensive-drug class on interindividual variation in blood pressure and risk of stroke: a systematic review and meta-analysis

Unexplained differences between classes of antihypertensive drugs in their effectiveness in preventing stroke might be due to class effects on intraindividual variability in blood pressure. We did a systematic review to assess any such effects in randomised controlled trials.