Stroke unit care revisited: who benefits the most? A cohort study of 105,043 patients in Riks-Stroke, the Swedish Stroke Register.

BACKGROUND: Treatment at stroke units is superior to treatment at other types of wards. The objective of the present study is to determine the effect size of stroke unit care in subgroups of patients with stroke. This information might be useful in a formal priority setting. METHODS: All acute strokes reported to the Swedish Stroke Register from 2001 through 2005 were followed until January 2007. The subgroups were age (18-64, 65-74, 75-84, 85+ years and above), sex (male, female), stroke subtype (intracerebral haemorrhage, cerebral infarction and unspecified stroke) and level of consciousness (conscious, reduced, unconscious). Cox proportional hazards and logistic regression analyses were used to estimate the risk for death, institutional living or dependency. RESULTS: 105,043 patients were registered at 86 hospitals. 79,689 patients (76%) were treated in stroke units and 25,354 patients (24%) in other types of wards. Stroke unit care was associated with better long-term survival in all subgroups. The best relative effect was seen among the following subgroups: age 18-64 years (hazard ratio (HR) for death 0.53; 0.49 to 0.58), intracerebral haemorrhage (HR 0.61; 0.58 to 0.65) and unconsciousness (HR 0.70; 0.66 to 0.75). Stroke unit care was also associated with reduced risk for death or institutional living after 3 months. CONCLUSIONS: Stroke unit care was associated with better long-term survival in all subgroups, but younger patients, patients with intracerebral haemorrhage and patients who were unconscious had the best relative effect and may be given the highest priority to this form of care.

[Life after stroke--a new national study. Renewed follow-up of stroke patients shows increased dependency on the support from the next-of-kin]. / Livet efter stroke--ny nationell studie. Förnyad uppföljning av strokedrabbade visar okande beroende av anhöriga.

The National Board of Health and Welfare together with Riks-Stroke (the Swedish National Registry for Quality Assessment of Acute Stroke Care) initiated a follow-up 2 years after a stroke event in 10,303 individuals, registrated in Riks-Stroke during the first 6 months of 2001. The aim was to evaluate the health status of the patients and the burden and needs of the spouses. 6,695 patients (65 percent) were alive. 4,729 patients (71 percent) answered the questionnaire. 2,367 spouses answered a separate questionnaire. This study was compared with an almost identical study performed four years earlier. The results showed that more patients lived at home and were satisfied with help and support. Rehabilitation was still deficient for 30 percent, and more patients were highly dependent on support from next-of-kin. Thirty percent could stay alone less than half a day. These results will be used for improving rehabilitation for the stroke patients and support for their spouses.

Differences in long-term outcome between patients treated in stroke units and in general wards: a 2-year follow-up of stroke patients in sweden.

BACKGROUND AND PURPOSE: The long-term beneficial effects of stroke unit care have been proved in several randomized trials. However, there is a question of large-scale applicability in routine clinical practice of interventions used by dedicated investigators in small randomized trials. The objective of this study was to compare, 21/2 years after stroke, patients who had been treated in stroke units and those treated in general wards in routine clinical practice. METHODS: This is a prospective cohort study based on 8194 patients who were included, during the first 6 months in 1997, in Riks-Stroke, the Swedish National Register for quality assessment of acute stroke. Two years after the event, 5189 patients were still alive and 5104 were followed up with a postal questionnaire to which 4038 responded. RESULTS: Among the group of patients who were independent in activities of daily living (ADL) functions before the stroke, patients who were treated in stroke units were less often dependent in ADL functions, after adjustment for case mix (OR, 0.79; CI, 0.66 to 0.94). If they also lived at home before the stroke, then they had a lower case-fatality rate 2 years after the stroke (OR, 0.81; CI, 0.72 to 0.92). CONCLUSIONS: Long-term beneficial effects of treatment in stroke units were shown for patients who were independent in ADL functions before the stroke. No benefits were shown for patients who were dependent on help for primary ADL before the stroke. Further studies on this group of patients with more detailed outcome measures are needed.

Potassium/magnesium depletion in patients with cardiovascular disease.

Diuretic-induced deficiencies in potassium and magnesium can have significant implications for patients with cardiovascular disease. Hypokalemia, found in up to 50 percent of patients receiving thiazide therapy, is associated with a greater frequency of serious arrhythmias and increased mortality in patients with acute myocardial infarction. Hypomagnesemia has been identified in 42 percent of patients with hypokalemia, and below normal muscle magnesium levels have been found in 43 percent of congestive heart failure patients receiving diuretics. Magnesium is important for maintenance of cell potassium, and infusions of magnesium alone have increased muscle potassium and magnesium levels and significantly decreased the frequency of ventricular ectopic beats. It has been shown that both potassium and magnesium are conserved by potassium-sparing agents. Because serum and tissue magnesium levels are not correlated and correlations for potassium levels are weak, prevention of these electrolyte abnormalities is advised.

Antihypertensive efficacy and side effects of three beta-blockers and a diuretic in elderly hypertensives: a report from the STOP-Hypertension study.

OBJECTIVE: To compare the blood pressure-lowering efficacy, the frequency of side effects and changes in laboratory values of three beta-blockers and a potassium-sparing diuretic combination in elderly hypertensive patients. DESIGN: The Swedish Trial in Old Patients with Hypertension (STOP-Hypertension) was a prospective, randomized, double-blind, multicentre trial comparing active antihypertensive treatment with placebo in patients aged 70-84 years. METHODS: The study group consisted of 1627 elderly hypertensive patients (mean +/- SD age 75.7 +/- 3.7 years; 37% males, 63% females). Supine and standing blood pressure, heart rate and side effects were recorded at each visit. Blood was drawn for routine analysis. The mean length of follow-up was 25 months (range 6-65). No patient was lost to follow-up. RESULTS: After 2-months' single-drug therapy, all four active drugs were found to be equally effective in reducing diastolic blood pressure (DBP). However, there were differences in their efficacy in reducing systolic blood pressure (SBP); the diuretic was significantly more effective than the beta-receptor blockers. The results of a series of multiple linear regression analyses showed that the observed differences in effect on SBP could not be explained by the different effects of the drugs on heart rate. More than two-thirds of the patients were given supplementary treatment, most of them already by the 2-month visit, after which there was no significant difference in blood pressure among the treatment regimens. The changes in laboratory values and in the prevalence of symptoms were minor for all four regimens. CONCLUSION: Metoprolol (controlled release), atenolol, pindolol and the combination hydrochlorothiazide + amiloride were equally effective as single drugs in reducing DBP. There were differences in their efficacy in reducing SBP, the diuretic being more effective than the beta-blockers. After addition of supplementary treatment (beta-blocker to diuretic, or vice versa) there were no significant differences in blood pressure reduction among the groups. The changes in laboratory values and in the prevalence of symptoms were minor for all active treatment regimens. Thus, the satisfactory effect on cardiovascular morbidity and mortality was not impaired by low tolerability of the drugs.

Comparison of antihypertensive treatments in preventing cardiovascular events in elderly diabetic patients: results from the Swedish Trial in Old Patients with Hypertension-2. STOP Hypertension-2 Study Group.

BACKGROUND: The benefits of treating hypertension in elderly diabetic patients, in terms of achieving reductions in cardiovascular morbidity and mortality, have been documented in several recent prospective trials. There has, however, been some controversy regarding the effect of different antihypertensive drugs on the frequency of myocardial infarction in this group of patients. DESIGN: STOP Hypertension-2 was a prospective, randomized, open trial with blinded endpoint evaluation. METHODS: We studied 6614 elderly patients aged 70-84 years; 719 of them had diabetes mellitus at the start of the study (mean age 75.8 years). Patients were randomly assigned to one of three treatment strategies: conventional antihypertensive drugs (diuretics or beta-blockers), calcium antagonists, or angiotensin converting enzyme (ACE) inhibitors. RESULTS: Reduction in blood pressure was similar in the three treatment groups of diabetics. The prevention of cardiovascular mortality was also similar; the frequency of this primary endpoint did not differ significantly between the three groups. There were, however, significantly fewer (P = 0.025) myocardial infarctions during ACE inhibitor treatment (n = 17) than during calcium antagonist treatment (n = 32; relative risk 0.51, 95% confidence interval 0.28-0.92); but a (non-significant) tendency to more strokes during ACE inhibitor treatment (n = 34 compared with n = 29; relative risk 1.16, 95% confidence interval 0.71-1.91). CONCLUSION: Treatment of hypertensive diabetic patients with conventional antihypertensive drugs (diuretics, beta-blockers, or both) seemed to be as effective as treatment with newer drugs such as calcium antagonists or ACE inhibitors.

Electrolyte balance in heart failure and the role for magnesium ions.

It is well established that clinically significant changes in a number of electrolytes occur in patients with congestive heart failure (CHF). Magnesium ions are an essential requirement for many enzyme systems, and evidence is rapidly emerging that magnesium deficiency is a major risk factor for survival of CHF patients. In animal experiments, magnesium has been shown to be involved in several steps of the atherosclerotic process and, although in humans the situation is somewhat more complex, magnesium ions play an extremely important role in CHF and various cardiac arrhythmias. A number of drugs commonly used to treat CHF can significantly affect not only cellular magnesium ion homeostasis, but potassium as well. These include mercurial, thiazide, and loop diuretics. It has also been reported that hypomagnesemia is common in digitalis intoxication. In contrast, a number of agents have been shown to have either a magnesium-conserving effect (potassium-sparing diuretics) or not to affect magnesium ion balance (angiotensin-converting enzyme inhibitors). The clinical consequences of magnesium deficiency include the development of various cardiac arrhythmias, all of which respond well to magnesium treatment. Thus, it is more than apparent that magnesium ion homeostasis is of major importance in CHF. Future studies should address the complex role of magnesium ions in electrolyte imbalance, particularly in relation to heart failure.

Intracellular magnesium loss after diuretic administration.

Diuretic agents influence the renal handling of magnesium, causing increased losses of the ion. Continuing magnesium losses may, in the long term, result in a magnesium deficiency. 296 patients with congestive heart failure or arterial hypertension receiving long term diuretic therapy were studied by skeletal muscle biopsies to assess their magnesium status. 65% of the congestive heart failure patients and 42% of the patients with arterial hypertension were found to have subnormal values for skeletal muscle magnesium. Studies with the potassium-sparing diuretics amiloride, spironolactone and triamterene demonstrate that these drugs significantly increase the muscle magnesium content in patients on long term diuretic treatment for congestive heart failure and/or arterial hypertension--in addition to their well known positive effect on potassium balance.

Improvement in pulmonary function with diuretic therapy in the hypervolemic and polycythemic patient with chronic obstructive pulmonary disease.

Central hemodynamics and gas exchange were studied in six patients with chronic obstructive pulmonary disease (mean age, 60 years). Patients were selected for the study if the volume of blood was 1 L larger than the predicted normal value, if there was no history of infection, and if no drug assumed to influence pulmonary circulation had been given during the last four weeks. Measurements were first performed in the hypervolemic state. This was followed by a venesection of 0.5 L, and the measurements were repeated 15 minutes later (immediate effects of dehydration). After two weeks to two months of intensive diuretic therapy, new measurements were performed (long-term effects of dehydration). With hypervolemia, there was pulmonary hypertension, increased pulmonary vascular resistance, and normal cardiac output. The arterial oxygen tension (PaO2) was markedly reduced. The arterial carbon dioxide tension (PaCO2) was increased in two patients, and dead-space ventilation (VD/VT) increased in all. The sole immediate effect of venesection was a small increase in heart rate and a reduction in PaCO2. The long-term effects were a maintained low blood volume (on the average, 0.7 L less than before bloodletting) and lowered hematocrit reading (8 percent less than before bloodletting), a reduced and in some patients normalized pulmonary arterial pressure, a reduced pulmonary vascular resistance, and an unchanged cardiac output. The PaO2 improved, while PaCO2 did not change; neither did VD/VT. The changes correlated partly with the diminution in blood volume and partly with the reduction in hematocrit reading.

Changing social patterns of risk factors for cardiovascular disease in a Swedish community intervention programme.

Since 1985 a small-scale community-based cardiovascular disease (CVD) preventive programme has been in operation in an inland municipality, Norsjö, in Northern Sweden. The aim of this study was to assess the development of the relationship between social position and CVD risk factors in repeated cross-sectional surveys (1985-1990) among all men and women aged 30, 40, 50 and 60 years in the study area, using an age-stratified random sample from the Northern Sweden MONICA Study of 1986 and 1990 as reference population. These multiple cross-sectional surveys comprised a self-administered questionnaire and a health examination. Of the study population 95% (n = 1499) and 80% of those in the reference area (n = 3208) participated. Subjects were classified with regard to demographic, structural and social characteristics in relation to CVD risk factors and self-reported health status. Time trends in classical risk factor occurrence were assessed in terms of age- and sex- adjusted odds ratios using Mantel-Haenszel procedures. When simultaneously adjusting for several potential confounders we used a logistic regression analysis. Initially, more than half of the study population, both males and females, had and elevated (> or = 6.5 mmol/l) serum cholesterol level. After adjustments had been made for age and social factors it was found that the relative risk of hypercholesterolaemia dropped substantially and significantly among both sexes during the 6 years of CVD intervention in the study area. However, the probability of being a smoker was significantly reduced only in highly educated groups. Among other risk factors no single statistically significant change over time could be found. In the reference area there were no changes over time for the selected CVD risk factors. People in the study area had a less favourable perception of their health than those in the reference area. Social differences were found when perceived good health was measured, especially in variables indicating emotional and social support. When sex, age and social factors had been accounted for there was not clear change over the years in perceived good health.

The dose-dependent reduction in blood pressure through administration of magnesium. A double blind placebo controlled cross-over study.

Seventeen patients with a diastolic blood pressure over 90 mm Hg were recruited from a running health screening program to participate in a double blind cross-over study of magnesium supplementation (15 mmol Mg2+/day (Emgesan, Kabi Pharmacia) for 3 weeks, followed by 30 mmol Mg2+/day for another 3 weeks, finishing with 40 mmol Mg2+/day for a final 3 weeks). A significant decrease in the mean systolic blood pressure was recorded from 154.0 +/- 10.7 mm Hg to 146.1 +/- 16.9 mm Hg (P = .031) while the mean diastolic blood pressure decreased from 100.2 +/- 4.2 mm Hg to 92.0 +/- 6.6 mm Hg (P = .0001).

Effects of magnesium infusion on thrombolytic and non-thrombolytic treated patients with acute myocardial infarction.

UNLABELLED: A total of 109 consecutive patients were included in a double blind, randomized trial of the effect of intravenous magnesium sulfate in acute myocardial infarction. Of these 63% received intravenous fibrinolytic therapy. Twenty four-hour Holter monitoring of heart rhythm was performed during the initial hospital stay. A significant reduction in total cardiac mortality in hospital and during the 9 months follow-up was found in the magnesium treated non-thrombolytic group (P < 0.05). Within this subgroup development of heart failure was decreased (P < 0.01). No effect of magnesium infusion on ventricular arrhythmias was demonstrated, instead we found a greater proportion of patients with short runs of ventricular tachycardias in the magnesium treated non-thrombolytic group (P < 0.05), which may represent an increase in spontaneous reperfusion. CONCLUSION: these results indicates that magnesium infusion may have a beneficial effect on mortality in patients with acute myocardial infarction not receiving thrombolytic therapy, but opposes the view that the benefit is related to an antiarrhythmic effect. No additional effect of magnesium to ongoing fibrinolytic therapy could be demonstrated regarding mortality, reinfarction and heart failure.

Effects of peroral magnesium on plasma and skeletal muscle electrolytes in patients on long-term diuretic therapy.

Twenty patients on long-term diuretic therapy for arterial hypertension and/or congestive heart failure were given a supplementary dose of 15 mmol magnesium aspartate hydrochloride per day for 6 months. Nineteen patients, fulfilling the same admission criteria as the treatment group, served as controls. The addition of magnesium aspartate hydrochloride resulted in a significant rise of the cellular potassium and magnesium content and in a significant decrease of both systolic and diastolic blood pressure. It is concluded that supplementation with magnesium aspartate hydrochloride may effectively prevent the diuretic induced disturbances of electrolyte balance.

Effects of intravenous magnesium sulphate in suspected acute myocardial infarction on acute arrhythmias and long-term outcome.

A total of 252 patients with suspected acute myocardial infarction were included in a double blind study and randomised to 50 mmol magnesium sulfate infusion under 20 h or corresponding placebo. Acute myocardial infarction was verified in 117 patients and 59% of these had concomitant treatment with thrombolysis. One-hundred ninety-four patients had Holter registrations during the first day in the coronary care unit. Intention-to-treat analysis showed an increase in long RR-intervals (> 3 s) in the magnesium treated group (P = 0.006) and a tendency toward a reduction in episodes of ventricular premature complexes in triplets (P = 0.09). During hospital stay and a mean of 22 months follow-up, 23 fatal events occurred in the magnesium allocated group and 31 fatal events among the placebo allocated group (P = 0.1). Mortality rate from cardiac disease was reduced by 54% (95% C.I. 30-99%, P < 0.05). Subgroup analysis on acute myocardial infarction patients showed a 48% mortality risk reduction in the magnesium treated acute myocardial infarction group compared to the placebo treated acute myocardial infarction group (95% C.I. 23-104%, P = 0.06). There was no significant interaction between the effects of magnesium and thrombolytic treatment on total mortality or cardiac events. This study supports the results of other small double blind placebo controlled studies regarding effects of magnesium therapy on mortality in acute myocardial infarction, but are in discordance to the conclusion from the ISIS-4 study. The reasons for these discrepancies cannot be elucidated by our data.

Magnesium therapy, fibrinolytic parameters and von Willebrand factor in acute myocardial infarction.

Sixty-one patients with non-thrombolytic treated acute myocardial infarction were randomised to open magnesium infusion or control. tPA activity, tPA mass, PAI-1 mass and von Willebrand factor (vWF) were measured in blood samples drawn at entrance and after on average 10 h and 18 h following inclusion in the trial. No differences for the hemostatic variables assay type were detected between the two groups. Fluctuations in the fibrinolytic parameters were maintained in the magnesium group, but blunted in the control group regarding PAI-mass and tPA-activity. This study gives no evidence that magnesium infusion in acute myocardial infarction influences fibrinolytic parameters or vWF.

Antimony in lung, liver and kidney tissue from deceased smelter workers.

Tissue concentrations of antimony in lung, liver, and kidney tissue from a group of deceased smelter workers from northern Sweden have been compared with those of a group of persons without occupational exposure from a nearby area. Neutron activation analysis was used to determine the antimony concentration of lung tissue from exposed workers; these concentrations were 12-fold higher than those of referents (p less than 0.001). For lung tissue there was no tendency towards decreased antimony concentrations with time (up to 20 a) after the cessation of exposure, and this result indicates a long biological half-time. The highest values were found for workers who had worked for many years at the roasters and in the arsenic and selenium departments. There was no significant difference between the antimony concentration of the lung tissue from workers who had died of lung cancer and those of persons who died of other malignancies, cardiovascular disease, or other causes. This finding does not however rule out the possibility of a role for antimony in the etiology of lung cancer among smelter workers since multiple factors may have been operating. The antimony concentration of the liver tissue and the kidney cortex did not differ from the corresponding values of the reference group; this finding indicates either a short biological half-time or insignificance for the systemic distribution of antimony.

Metallic contamination of food during preparation and storage: development of methods and some preliminary results.

A chemical procedure for studying trace metals leached from metallic cooking utensils and preserving cans used in the preparation and storage of food has been developed. The method consists in the destruction of the major part of organic matter with HNO3-vapour followed by a complete mineralization of residues with small amounts of HNO3 in Teflon bombs at 150-160 degrees C under a pressure of 3-12 kg/cm2, depending on the amount and composition of the samples. Subsequently, an ion-exchange step removes major components and concentrates the trace elements in a dilute HNO3-solution, suitable for analysis. The ion-exchange separation, which is performed with an automatic ion-exchange separator, is practically free from blank level problems, e.g., typically a mean of less than 2 per cent of the sample levels of the elements being determined. Preliminary results show that large amounts of aluminium are released from vessels to the water during boiling at the same pH-range which exist for most drinking water in Sweden.

Distribution of 23 elements in the kidney, liver and lungs of workers from a smeltery and refinery in North Sweden exposed to a number of elements and of a control group.

The levels of antimony, arsenic, cadmium, caesium, chromium, cobalt, copper, gold, iron, lanthanum, lead, manganese, mercury, molybdenum, phosphorus, rubidium, scandium, selenium, silver, tellurium, tin, tungsten and zinc in the kidney, liver and lungs of autopsy specimens from exposed workers in North Sweden, as well as from a control group, have been assayed quantitatively. The workers had been exposed to several elements and their compounds, e.g. lead, mercury, arsenic and cadmium, for long periods in arsenic, lead or selenium plants and in a lead or copper smelter. The chemical analysis was by neutron activation analysis and atomic absorption spectrophotometry. Median levels of antimony, arsenic, cadmium, chromium cobalt, lanthanum, lead or selenium in kidney, liver or lungs in the exposed worker group were found to be about 2 to 16 times as great as the corresponding levels for the control group. Long biological half-life values were observed for these elements, especially in lung tissue.

Multielemental assay of tissues of deceased smelter workers and controls.

Concentrations of 23 elements in lung, liver and kidney from deceased smelter workers are compared with those from rural and urban controls. The analyses were made by neutron activation analysis and atomic absorption spectrophotometry. Significantly higher levels of antimony, arsenic, cadmium, chromium, cobalt, lanthanum, lead and selenium were found in the smelter workers lungs (n = 85) compared with the rural controls (n = 15). Significantly higher concentrations of antimony, arsenic and lead were observed among all smelter workers compared with urban controls (n = 10). The highest increase, about 11-fold, was found for antimony in smelter workers compared with non-exposed controls. A six-fold increase was noted for arsenic. Workers who died from lung cancer (n = 7) had the lowest lung selenium content relative to concentrations of other metals, both compared with other disease categories among the workers (GI-cancer, other cancers, cardiovascular diseases, cerebrovascular diseases, other causes) and with the two control groups. The low lung selenium concentrations may have influenced the development of lung cancer. The highest lung tissue levels of cadmium were found in the lung cancer group. Smokers and ex-smokers were over-represented in this group and tobacco is a known cadmium source. The highest, or one of the highest, lung values for some of the other metals (antimony, arsenic, cadmium, lanthanum and lead) were observed in one or several of the lung cancer cases. Metal concentrations in liver (metabolism) and kidney (excretion) reflect the systemic distribution. The highest cadmium levels in the liver and the lowest selenium content in the kidney were found among the lung cancer cases. A multifactorial genesis for the development of lung cancer is concluded from this study, which visualizes the need for systematic health surveillance and follow-ups both in active and retired workers.

Distribution of cadmium, lead and zinc in lung, liver and kidney in long-term exposed smelter workers.

Increased mortality due to various malignancies is reported from long-term exposed, non-ferrous smelter workers. In the present study the post-mortem distribution of cadmium, lead and zinc in lung, liver and kidney is reported and related to exposure and mortality. The study involved 86 male copper smelter workers who died after April 1975. Lung samples were taken from all workers and liver and kidney samples were taken from about one-quarter of the workers. Two control groups were used. The exposed workers were divided into six groups based upon diagnoses in medical records and autopsy protocols. Lead and zinc were analyzed by atomic absorption spectrophotometry and cadmium by neutron activation analysis. For the skewly distributed tissue levels, non-parametric statistical processing was used. Of the workers, 53% died from cardiovascular diseases and 30% from malignancies (8% from lung cancer). Cardiovascular diseases predominated in the two control groups: about 75 and 100%, respectively. Lung and liver cadmium concentrations were significantly higher in the lung cancer group of smelter workers than in the other groups of smelter workers (p less than 0.05) and rural controls (p less than 0.01). Cadmium in kidney, and lead in lung and liver were significantly higher (p less than 0.03) in the lung cancer group than in rural controls, but did not differ from that of the other workers. Zinc in lung, liver and kidney did not differ between exposed workers and controls. Rather strong Spearman rank-order correlation coefficients were found between the cadmium content of lung, liver and kidney tissue, especially in non-smoking smelter workers and rural controls. Smoking was more common in the lung cancer group than in the total group of smelter workers. Cadmium levels in the lungs of exposed workers were significantly higher (p less than 0.001) in smokers than in both ex-smokers and non-smokers. Earlier studies of the same workers gave significantly lower selenium levels in lung tissue compared with other groups of smelter workers and controls. As other carcinogenic substances are present in the working environment, e.g. arsenic, chromium and benzo [alpha]-pyrene, the specific effect of cadmium in the development of lung cancer cannot be evaluated at present.