Arterial hypertension and diastolic blood pressure associate with aortic stenosis.

OBJECTIVES: Due to age-related differences in aortic valve structure, it is likely that the pathophysiology of aortic stenosis (AS) and associated risk factors differ between age groups. Here we prospectively studied the influence of traditional cardiovascular risk factors on AS development requiring surgery among patients without concomitant coronary artery disease (CAD) and stratified for age. DESIGN: This study included 322 patients, who had prior to surgery for AS participated in population-based surveys, and 131 of them had no visible CAD upon preoperative coronary angiogram. For each case, we selected four referents matched for age, gender, and geographic area. To identify predictors for surgery, we used multivariable conditional logistic regression with a model including arterial hypertension (or measured blood pressure and antihypertensive medication), cholesterol levels, diabetes, body mass index (BMI), and smoking. RESULTS: In patients without CAD, future surgery for AS was associated with arterial hypertension and elevated levels of diastolic blood pressure in patients younger than 60 years at surgery (odds ratio [95% confidence interval]), (3.40 [1.45-7.93] and 1.60 [1.09-2.37], respectively), and with only impaired fasting glucose tolerance in patients 60 years or older at surgery (3.22 [1.19-8.76]). CONCLUSION: Arterial hypertension and elevated diastolic blood pressure are associated with a risk for AS requiring surgery in subjects below 60 years of age. Strict blood pressure control in this group is strongly advocated to avoid other cardiovascular diseases correlated to hypertension. If hypertension and elevated diastolic blood pressure are risk factors for developing AS requiring surgery need further investigations. Notably, elevated fasting glucose levels were related to AS requiring surgery in older adults without concomitant CAD.

The use of a screening scale improves the recognition of delirium in older patients after cardiac surgery-A retrospective observational study.

AIMS AND OBJECTIVES: To analyse postoperative delirium (POD) in clinical practice after cardiac surgery, how it is detected and documented and if the use of a screening scale improves the detection rate. BACKGROUND: Cardiac surgery is considered a routine procedure with few complications. However, POD remains a concern, although often being overlooked in clinical practice. DESIGN: Retrospective observational analysis. METHODS: Patients 70 years and older with POD (n = 78) undergoing cardiac surgery were included in the study. Discharge summaries of both nurses and physicians were reviewed together with the clinical database for information about POD, to be compared with symptom screening using the Nursing Delirium Screening Scale (Nu-DESC). A quantitative content analysis was used for the review of discharge summaries, with a coding scheme adopted from the Nu-DESC method. The STROBE checklist was followed. RESULTS: In discharge summaries, 41 of the 78 POD patients were correctly recognised, and 22 of these were identified in the clinical database. Screening by the Nu-DESC identified delirium at a measurably higher rate, 56/78 patients. The review of discharge summaries showed that patients expressing "inappropriate behaviour" was the most easily identified sign for POD for both nurses and physicians. CONCLUSIONS: Healthcare professionals underdiagnose delirium after cardiac surgery, with a low detection rate described in both discharge summaries and in the clinical database. Recognition of delirium improved when Nu-DESC was used for systematic screening. RELEVANCE TO CLINICAL PRACTICE: This study emphasises the need for better screening for the detection of delirium in daily clinical practice.

Mass Casualty Incidents in the Underground Mining Industry: Applying the Haddon Matrix on an Integrative Literature Review.

OBJECTIVE: Underground mining is associated with obvious risks that can lead to mass casualty incidents. Information about such incidents was analyzed in an integrated literature review. METHODS: A literature search (1980-2015) identified 564 modern-era underground mining reports from countries sharing similar occupational health legislation. These reports were condensed to 31 reports after consideration of quality grading and appropriateness to the aim. The Haddon matrix was used for structure, separating human factors from technical and environmental details, and timing. RESULTS: Most of the reports were descriptive regarding injury-creating technical and environmental factors. The influence of rock characteristics was an important pre-event environmental factor. The organic nature of coal adds risks not shared in hard-rock mines. A sequence of mechanisms is commonly described, often initiated by a human factor in interaction with technology and step-wise escalation to involve environmental circumstances. Socioeconomic factors introduce heterogeneity. In the Haddon matrix, emergency medical services are mainly a post-event environmental issue, which were not well described in the available literature. The US Quecreek Coal Mine incident of 2002 stands out as a well-planned rescue mission. CONCLUSION: Evaluation of the preparedness to handle underground mining incidents deserves further scientific attention. Preparedness must include the medical aspects of rescue operations. (Disaster Med Public Health Preparedness. 2018;12:138-146).

Disturbances in Oxygen Balance During Cardiopulmonary Bypass: A Risk Factor for Postoperative Delirium.

OBJECTIVE: The aim of this study was to determine risk factors for postoperative delirium after cardiac surgery, specifically associated with the conduct of cardiopulmonary bypass (CPB). DESIGN: Prospective observational study. SETTING: Heart Centre, University Hospital. PARTICIPANTS: The study included 142 patients aged 70 years and older scheduled for elective cardiac surgery with CPB. INTERVENTIONS: Risk factor analysis comprised information collected from the hospital clinical and CPB dedicated databases in addition to the medical chart. Delirium was diagnosed according to the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision criterion using the Mini Mental State Examination and the Organic Brain Syndrome scale. MEASUREMENTS AND MAIN RESULTS: Assessments of delirium diagnosis were executed preoperatively and on the following first and fourth postoperative days. Delirium occurred in 55% (78/142) of the patients. Patients with delirium were identified with significantly higher body weight and body surface area preoperatively, accompanied with longer CPB time, higher positive fluid balance per CPB, and lower systemic pump flow related to body surface area. Furthermore, the duration of the mixed venous oxygen saturation (SvO2) below 75% was significantly longer during CPB. The result from the multivariable logistic regression analysis included the duration of SvO2 below 75%, fluid balance per CPB and patient age as independent risk factors for postoperative delirium. CONCLUSIONS: The influence of the SvO2 level during CPB, fluid balance, and patient age should be recognized as risk factors for postoperative delirium after cardiac surgery in patients 70 years and older.

Preoperative Cognitive Performance and Postoperative Delirium Are Independently Associated With Future Dementia in Older People Who Have Undergone Cardiac Surgery: A Longitudinal Cohort Study.

OBJECTIVE: To investigate if postoperative delirium was associated with the development of dementia within 5 years after cardiac surgery. DESIGN: Longitudinal cohort study. SETTING: Cardiothoracic Division, Umeå University Hospital, Sweden. PATIENTS: Patients aged 70 years old or older (n = 114) scheduled for routine cardiac procedures with cardiopulmonary bypass without documented dementia were enrolled in 2009. INTERVENTION: Structured assessments were performed preoperatively, 1 and 4 days after extubation, and 1, 3, and 5 years postoperatively. MEASUREMENTS AND MAIN RESULTS: Patients were assessed comprehensively, including cognitive and physical function, coexisting medical conditions, demographic characteristics, and medications. Diagnoses of delirium, depression, and dementia were made according to Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision criteria. During the 5-year period, 30 of 114 participants (26.3%) developed dementia. Postoperative delirium had occurred in 87% of those who later developed dementia. A multivariable logistic regression model showed a lower preoperative Mini-Mental State Examination score (p < 0.001; odds ratio, 0.68; 95% CI, 0.54-0.84) and the occurrence of postoperative delirium (p = 0.002; odds ratio, 7.57; 95% CI, 2.15-26.65) were associated with dementia occurrence. CONCLUSIONS: Our findings suggest that older patients with reduced preoperative cognitive functions or who develop postoperative delirium are at risk of developing dementia within 5 years after cardiac surgery. Cognitive functions should be screened for preoperatively, those who develop postoperative delirium should be followed up to enable early detection of dementia symptoms, and management should be implemented.

Traditional Cardiovascular Risk Factors and Their Relation to Future Surgery for Valvular Heart Disease or Ascending Aortic Disease: A Case-Referent Study.

BACKGROUND: Risk factors for developing heart valve and ascending aortic disease are based mainly on retrospective data. To elucidate these factors in a prospective manner, we have performed a nested case-referent study using data from large, population-based surveys. METHODS AND RESULTS: A total of 777 patients operated for heart valve disease or disease of the ascending aorta had previously participated in population-based health surveys in Northern Sweden. Median time (interquartile range) from survey to surgery was 10.5 (9.0) years. Primary indications for surgery were aortic stenosis (41%), aortic regurgitation (12%), mitral regurgitation (23%), and dilatation/dissection of the ascending aorta (17%). For each case, referents were allocated, matched for age, sex, and geographical area. In multivariable models, surgery for aortic stenosis was predicted by hypertension, high cholesterol levels, diabetes mellitus, and active smoking. Surgery for aortic regurgitation was associated with a low cholesterol level, whereas a high cholesterol level predicted surgery for mitral regurgitation. Hypertension, blood pressure, and previous smoking predicted surgery for disease of the ascending aorta whereas diabetes mellitus was associated with reduced risk. After exclusion of cases with coronary atherosclerosis, only the inverse associations between cholesterol and aortic regurgitation and between diabetes mellitus and disease of the ascending aorta remained. CONCLUSIONS: This is the first truly prospective study of traditional cardiovascular risk factors and their association with valvular heart disease and disease of the ascending aorta. We confirm the strong association between traditional risk factors and aortic stenosis, but only in patients with concomitant coronary artery disease. In isolated valvular heart disease, the impact of traditional risk factors is varying.

Validation of the confusion assessment method in detecting postoperative delirium in cardiac surgery patients.

BACKGROUND: Early detection, prevention, and treatment of delirium after cardiac surgery are important for quick postoperative recovery. The Confusion Assessment Method (CAM) may be an easy-to-use instrument for detecting delirium in clinical practice. OBJECTIVES: To compare the congruent validity of the CAM with the results from repeated assessments by using a combination of the Organic Brain Syndrome Scale and the Mini-Mental State Examination according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria for delirium. METHODS: Patients aged 70 years or older undergoing cardiac surgery were assessed on postoperative days 1 and 4, and the 2 diagnostic methods were compared. The sensitivity and specificity of the CAM were examined. The reference method allowed categorization of delirium into subgroups of psychomotor activities and psychiatric symptom profiles, which were compared with the CAM results. RESULTS: Postoperative delirium was diagnosed in 78 of 141 patients (55.3%). According to the CAM, 59 patients (41.8%) were categorized as delirious, 53 correctly. Thus, the sensitivity was 68% and the specificity was 90%, indicating false-negative rather than false-positive observations. CONCLUSION: Patients with psychomotor hyperactivity and mixed psychotic-emotional symptoms were more likely to have delirium detected via the CAM than were patients with less obvious clinical manifestations of delirium. Repetitive cognitive testing and psychogeriatric experience are probably necessary to improve the results obtained with the CAM.

The level of physical exercise is associated with self-reported health status (EQ-5D) in adults with congenital heart disease.

BACKGROUND: The prognosis in adults with congenital aortic valve disease is usually favourable; nevertheless, a number of medical and social factors might hamper long-term prognosis and quality of life. With a focus on physical exercise level, data from the Swedish National Registry on Congenital Heart Disease (SWEDCON) were analysed and variables associated with health-related quality of life in adults with congenital aortic valve disease were identified. METHODS: In this registry study, SWEDCON was searched for adult patients with isolated congenital aortic valve disease and valid EuroQol-5Dimensions health questionnaire (EQ-5D) data. RESULTS: This study identified 315 patients. The majority (n = 202, 64%) reported best possible health status (EQ-5D(index) = 1) whereas 113 (35%) reported some impairment (EQ-5D(index) < 1) with mean EQ-5D(index) 0.73 ± 0.17. In a multivariate logistic regression model, self-reported physical exercise > 3 h/week was independently associated with best possible health status (EQ-5D(index) = 1; p = 0.013). Moreover presence of cardiovascular symptoms (p < 0.001), active smoking (p = 0.002), history of valve surgery (p = 0.017), low educational level (p = 0.022), and higher systolic blood pressure (p = 0.029) were independently associated with impaired health status (EQ-5D(index) < 1). CONCLUSIONS: Physical exercise >3 h/week was, as a single variable, associated with best possible health status in adults with congenital aortic valve disease. In contrast, a number of medical and social factors are associated with worse self-reported health status. Among these, symptoms, smoking, and educational level are potential targets for modification and intervention. There is a need for studies investigating the effect of increased level of physical exercise in patients with congenital aortic valve disease.

Subtypes of bicuspid aortic valves in coarctation of the aorta.

Bicuspid aortic valves (BAVs) represent a wide morphologic and functional spectrum. In coarctation of the aorta, BAVs are common, but the proportion of BAV subtypes and their relation to aortic dimensions and development of late valve dysfunction are unknown. Sixty-two cardiovascular magnetic resonance investigations of patients with coarctation of the aorta were reviewed with respect to aortic valve morphology, aortic valve function, and aortic dimensions. BAVs were identified in 45 patients (72.6%), of which 13 (20.9%) were type-0 (two commissures), 28 (45.1%) type-1 (three commissures but fusion of one commissure with a raphe) and 4 (6.5%) valves were bicuspid but not possible to classify further. Patients with BAVs type-0 had larger dimensions in their sinus of Valsalva (35.5 ± 6.8 vs. 29.7 ± 2.7 mm, p = 0.002), ascending aorta (33.1 ± 6.2 vs. 26.0 ± 4.3 mm, p = 0.005) and sino-tubular junction (29.3 ± 7.4 vs. 24.2 ± 3.5 mm, p = 0.040) compared with tricuspid aortic valves (TAVs). Moderate and severe aortic valve disease was more common in BAV type-0 compared with BAV type-1 (p = 0.030) and TAV (p = 0.016). In a multivariate linear regression model BAV type-0 (p = 0.005), BAV type-1 (p = 0.011), age (p < 0.001), patient height (p = 0.009), and aortic valve disease (p = 0.035) were independently associated with increased diameter of the ascending aorta (R (2) of the model 0.54, p < 0.001). BAV type-0 is relatively common in coarctation of the aorta. Both BAV type-0 and type-1 are associated with increased diameter of the ascending aorta but this association is stronger for BAV type-0. Development of aortic valve disease is more common in BAV type-0 than in BAV type-1. Discrimination between BAV subtypes may potentially provide clinical and prognostic information in patients with coarctation of the aorta.

Validation of the Swedish version of the Nursing Delirium Screening Scale used in patients 70 years and older undergoing cardiac surgery.

AIMS AND OBJECTIVES: Validation of the Swedish version of the Nursing Delirium Screening Scale as a screening tool for nurses to use to detect postoperative delirium in patients 70 years and older undergoing cardiac surgery. BACKGROUND: Delirium is common among old patients after cardiac surgery. Underdiagnosis and poor documentation of postoperative delirium is problematic, and nurses often misread the signs. DESIGN: A prospective observational study. METHODS: Patients (n = 142) scheduled for cardiac surgery were assessed three times daily by the nursing staff using the Nursing Delirium Screening Scale. Nursing Delirium Screening Scale was compared with the Mini Mental State Examination and the Organic Brains Syndrome Scale, evaluated day one and day four postoperatively. Delirium was diagnosed according to Diagnostic and Statistical Manual of Mental Disorders - DSM-IV-TR criteria. RESULTS: A larger proportion of patients were diagnosed with delirium according to the Mini Mental State Examination and Organic Brains Syndrome Scale compared with the Nursing Delirium Screening Scale, both on day one and day four. The Nursing Delirium Screening Scale protocol identified the majority of hyperactive and mixed delirium patients, whereas several with hypoactive delirium were unrecognised. CONCLUSIONS: The Swedish version of the Nursing Delirium Screening Scale was easily incorporated into clinical care and showed high sensitivity in detecting hyperactive symptoms of delirium. However, in the routine use by nurses, the Nursing Delirium Screening Scale had low sensitivity in detecting hypoactive delirium, the most prevalent form of delirium after cardiac surgery. Nursing Delirium Screening Scale probably has to be combined with cognitive testing to detect hypoactive delirium. RELEVANCE TO CLINICAL PRACTICE: Nurses play a key role in detecting delirium. The Nursing Delirium Screening Scale was easy incorporated instrument for clinical practice and identified the majority of hyperactive and mixed delirium, but several of the patients with hypoactive delirium were unrecognised. Training of assessment and cognitive testing seems to be necessary to detect hypoactive delirium.

Delirium after cardiac surgery: incidence and risk factors.

OBJECTIVES: Delirium after cardiac surgery is a problem with consequences for patients and healthcare. Preventive strategies from known risk factors may reduce the incidence and severity of delirium. The present aim was to explore risk factors behind delirium in older patients undergoing cardiac surgery with cardiopulmonary bypass. METHODS: Patients (≥70 years) scheduled for routine cardiac surgery were included (n = 142). The patients were assessed and monitored pre-/postoperatively, and delirium was diagnosed from repeated assessments with the Mini-Mental State Examination and the Organic Brain Syndrome Scale, using the DSM-IV-TR criteria. Variables were analysed by uni-/multivariable logistic regression, including both preoperative variables (predisposing) and those extracted during surgery and in the early postoperative period (precipitating). RESULTS: Delirium was diagnosed in 78 patients (54.9%). Delirium was independently associated with both predisposing and precipitating factors (P-value, odds ratio, upper/lower confidence interval): age (0.036, 1.1, 1.0/1.2), diabetes (0.032, 3.5, 1.1/11.0), gastritis/ulcer problems (0.050, 4.0, 1.0/16.1), volume load during operation (0.001, 2.8, 1.5/5.1), ventilator time in ICU (0.042, 1.2, 1.0/1.4), highest temperature recorded in ICU (0.044, 2.2, 1.0/4.8) and sodium concentration in ICU (0.038, 1.2, 1.0/1.4). CONCLUSIONS: Delirium was common among older patients undergoing cardiac surgery. Both predisposing and precipitating factors contributed to delirium. When combined, the predictive strength of the model improved. Preventive strategies may be considered, in particular among the precipitating factors. Of interest, delirium was strongly associated with an increased volume load during surgery.

Stroke after cardiac surgery--hemispheric distribution and survival.

OBJECTIVES: Stroke following cardiac surgery may occur either in association with surgery (early) or occur postoperatively (delayed). The hemispheric distribution of lesions may provide information about embolic routes, which was analyzed here. DESIGN: In 10,809 patients undergoing cardiac surgery, early (n = 223) and delayed stroke (n = 116) were explored. Symptoms and computed tomography findings were evaluated to categorize hemispheric distributions. This was compared with pre- and intra-operative characteristics and survival, using logistic regression and Kaplan-Meier statistics. RESULTS: Early stroke had preponderance for the right rather than the left hemisphere (P = 0.009), whereas delayed stroke had a uniform distribution. Several intraoperative variables predicted the development of bilateral stroke compared with its unilateral counterpart. At multivariable analysis, the use of tranexamic acid was associated with bilateral stroke (P = 0.017), but was also associated with right rather than left-hemispheric stroke (P = 0.001). Bilateral lesions dramatically impaired survival versus those with unilateral lesions (P < 0.001). There was no survival difference between left and right-hemispheric stroke. CONCLUSIONS: When stroke, after cardiac surgery, is subdivided into early and delayed forms, it becomes evident that early, but not delayed stroke, demonstrates a hemispheric side difference. The preponderance for right-hemispheric lesions may indicate embolic mechanisms routed via the brachiocephalic trunk.

Endogenous gas formation--an in vitro study with relevance to gas microemboli during cardiopulmonary bypass.

UNLABELLED: Gas embolism is an identified problem during cardiopulmonary bypass (CPB). Our aim was to analyze the potential influence from gas solubility based on simple physical laws, here called endogenous gas embolism. Gas solubility decreases at higher temperature and gas bubbles are presumably formed at CPB warming. An experimental model to measure gas release was designed. Medium (water or blood retrieved from mediastinal drains, 14.6 mL) was incubated and equilibrated with gas (air, 100% oxygen, or 5% carbon dioxide in air) at low temperature (10 degrees C or 23 degrees C). At warming to 37 degrees C, gas release was digitally measured. Also, the effect of fluid motion was evaluated. At warming, the medium became oversaturated with dissolved gas. When fluid motion was applied, gas was released to form bubbles. This was exemplified by a gas release of .45% (.31/.54, medians and quartile range, volume percent, p = .007) and 1.26% (1.14/ 1.33, p = .003) when blood was warmed from 23 degrees C or 10 degrees C to 37 degrees C, respectively (carbon dioxide 5% in air). Consistent findings were seen for water and with the other types of gas exposure. The theory of endogenous gas embolization was confirmed with gas being released at warming. The endogenous gas formation demonstrated a dynamic pattern with oversaturation and with rapid gas released at fluid motion. The gas release at warming was substantial, in particular when the results were extrapolated to full-scale CPB conditions. The interference from endogenous gas formation should be considered in parallel to external sources of gas microemboli. KEYWORDS: cardiopulmonary bypass, gas embolization, microemboli, gas solubility, temperature.

The Scandinavian multicenter hemodynamic evaluation of the SJM Regent aortic valve.

BACKGROUND: 112 patients who received small and medium sized St. Jude Regent heart valves (19-25 mm) at 7 Scandinavian centers were studied between January 2003 and February 2005 to obtain non-invasive data regarding the hemodynamic performance at rest and during Dobutamine stress echocardiography (DSE) testing one year after surgery. MATERIAL AND METHODS: 46 woman and 66 men, aged 61.8 ± 9.7 (18-75) years, were operated on for aortic regurgitation (17), stenosis (65), or mixed dysfunction (30). Valve sizes were 19 mm (6), 21 mm (33), 23 mm (41), 25 mm (30). Two patients receiving size 27 valves were excluded from the hemodynamic evaluation. Pledgets were used in 100 patients, everted mattress in 66 and simple interrupted sutures in 21. Valve orientation varied and was dependent on the surgeons' choice. 34 patients (30.4%) underwent concomitant coronary artery surgery. RESULTS: There were two early deaths (1.8%) and three late deaths, one because of pancreatic cancer. Late events during follow-up were: non structural dysfunction (1), bleeding (2), thromboembolism (2). At one year follow up 93% of the patients were in NYHA classes 1-2 versus 47.8% preoperatively. Dobutamine stress echocardiography (DSE) was performed in a total of 66 and maximal peak stress was reached in 61 patients. During DSE testing, the following statistically significant changes took place: Heart rate increased by 73.0%, cardiac output by 85.5%, left ventriclular ejection fraction by 19.6%, and maximal mean prosthetic transvalvular gradient by 133.8%, whereas the effective orifice area index did not change. Left ventricular mass fell during one year from 215 ± 63 to 197 ± 62 g (p < 0.05). CONCLUSION: The Dobutamine test induces a substantial stress, well suitable for echocardiographic assessment of prosthesis valve function and can be performed in the majority of the patients. The changes in pressure gradients add to the hemodynamic characteristics of the various valve sizes. In our patients the St. Jude Regent valve performed satisfactory at rest and under pharmacological stress situation.

Early and delayed stroke after coronary surgery - an analysis of risk factors and the impact on short- and long-term survival.

OBJECTIVE: Stroke is a serious complication to cardiac surgery, and is generally considered as a uniform disease regardless of its temporal relationship to surgery. Our hypothesis suggests that stroke, in association with surgery, reflects other characteristics than stroke occurring with a free interval. This issue was here explored for risk factors and survival effects. METHODS: Data were collected from 7839 procedures of isolated coronary artery bypass grafting (CABG), 297 off-pump CABG, and 986 combined CABG and valve procedures. Records of patients with any signs of neurological complications were reviewed to extract 149 subjects with stroke at extubation (early, 1.6%) versus 99 patients having a free interval (delayed, 1.1%). Survival data were complete, with a median follow-up time of 9.3 years (maximum 16.3 years). Independent risk factors were analyzed by logistic regression and survival by Cox regression. RESULTS: Risk factors for early stroke were advanced age, high preoperative creatinine level, extent of aortic atherosclerosis, and long cardiopulmonary bypass time (all P<0.001). Factors associated with delayed stroke were female gender (P<0.001), unstable angina (P=0.003), previous cerebrovascular disease (P=0.009), inotropic support requirement (P<0.001), and postoperative atrial fibrillation (P<0.001). Stroke explained mortality not only in the early postoperative period (P<0.001), but also at long-term follow-up (P<0.001). Early and delayed stroke were associated with mortality hazard ratios (HRs) of 1.44 and 1.85 (P=0.008, P<0.001), respectively. However, for patients surviving their first postoperative year, early stroke did not influence long-term mortality (HR 1.07, P=0.695). This was in contrast to delayed stroke (HR 1.71, P=0.001). CONCLUSIONS: Early and delayed stroke differed in their related risk factors. The influence of stroke on short-term mortality was obvious and devastating. Mortality in association with early stroke mainly presented itself in the acute period, whereas for delayed stroke survival continued to be impaired also in the long-term perspective. Our report emphasizes that early and delayed stroke should be considered as two separate entities.

Evaluation of hyaluronan and calcifications in stenotic and regurgitant aortic valves.

OBJECTIVE: Hyaluronan (HA) is a major component of the interstitium and has been observed in normal heart valves. The function of HA in heart valves is unknown but contribution to biomechanical function has been proposed. The purpose of this investigation was to study the distribution of HA in relation to calcifications in diseased human aortic valves. METHODS: Human aortic valves were collected at aortic valve replacement, of whom nine patients had regurgitation and 13 stenotic disease. The valves were decalcified and stained for the visualisation of HA. The specimens were macroscopically evaluated for magnitude of calcification using image analysis. The microscopic amount and distribution of HA and calcifications were semiquantitatively evaluated using histochemistry. RESULTS: The overall HA staining showed an inverse relationship against the magnitude of observed valve calcifications (p<0.001) and type of disease (p=0.014). Multiple-group comparison revealed regionally reduced HA staining in diffuse and heavy calcified regions inside the valve (both p<0.001) compared with normal-structured parts of the valve. HA was concentrated on the ventricular side of the valve (p=0.002). CONCLUSIONS: The content of HA was reduced in calcified aortic valves and had a heterogeneous distribution, potentially contributing to poor valve function. HA may also be involved in the pathophysiological process in degenerative aortic stenosis.

Size distribution of embolic material produced at aortic cross-clamp manipulation.

OBJECTIVES: The association between aortic atherosclerosis and neurological damage during cardiac surgery is well recognized. The purpose was here to analyze the size distribution of particles produced at cross-clamp manipulation of the ascending aorta. DESIGN: A human cadaveric aortic perfusion model of retrograde design was applied (n=27). With this model, washout samples were collected from the pressurized ascending aorta during cross clamp manipulation. Before the experiment, the aorta was flushed to remove debris and with a baseline sample collected. The cross-clamp was opened to collect ten repeated aliquots with dislodged particles. Collected washout samples were evaluated by digital image analysis and microscopy. RESULTS: Cross-clamping produced a significant output of particles, which was seen for size intervals of 1 mm and smaller (p=0.002 to p=0.022). In all size intervals the particle output correlated with the degree of overall aortic calcification (p=0.002 to p=0.025). The model generated substantially more small-size particles than large debris (p<0.010). CONCLUSIONS: Aortic clamping was here verified to dislodge aortic debris which correlated with the degree of observed calcification. Macroscopic particles were few. In contrast, cross-clamping produced substantial numbers of small-size particles. These findings emphasize microembolic risks associated with cross-clamping of atherosclerotic vessels.

Hazards with electrocautery-induced decomposition of fatty acids--in view of lipid embolization.

OBJECTIVES: Electrocautery is an appreciated surgical tool, which however, generates immense heat and fat-tissue melting. In cardiac surgery, liquefied fat collects on the surface of blood in the pericardial cavity and becomes aspirated by the heart-lung machine for aortic recycling. Deposits seen in the brain microcirculation after surgery are caused by lipid embolism. This study investigates lipid chemistry, whether heat from electrocautery generates fatty-acid fragmentation and decomposition. DESIGN: Pericardial fat tissue was sampled from cardiac-surgery patients and from piglets. The human tissue was exposed to electrocautery, or to fixed temperatures in an in vitro model. Fatty-acid decomposition was explored by solid-phase microextraction gas chromatography and the distribution of fatty acids was measured. RESULTS: Fatty-acid decomposition demonstrated a temperature-effect relationship (p = 0.007). At 350°C the proportion of polyunsaturated fatty acids became heavily reduced or were abolished (p = 0.016). Electrocautery resulted in similar changes. CONCLUSIONS: Electrocautery induces a profound fatty-acid fragmentation to form short-chained compounds. The chemical and toxic nature of these compounds remains to be determined, including their clinical implications at blood recycling in cardiac surgery.

Postoperative atrial fibrillation is associated with late mortality after coronary surgery, but not after valvular surgery.

BACKGROUND: Numerous studies have attempted to determine the etiology and prophylactic measures concerning atrial fibrillation (AF) after cardiac surgery. However, limited data are available analyzing the association between postoperative AF and late mortality. We sought to determine if AF after cardiac surgery affects postoperative survival. METHODS: All cardiac surgery patients (n = 9,495) undergoing cardiac surgery between January 1994 and December 2004 were studied. The study population comprised coronary artery bypass graft surgery (CABG [n = 7,621]), valvular surgeries (n = 995), and their combination (n = 879). Patients affected by postoperative AF were identified, and long-term survival was obtained from Swedish population registry and evaluated using Cox proportional hazards methods to adjust for baseline differences. RESULTS: The overall AF incidence was 26.7%, subdivided into 22.9%, 39.8%, and 45.2% for CABG, valve surgery, and combined procedures, respectively. The median follow-up for the entire study population was 7.9 years (maximum, 13.4). Postoperative AF independently affected long-term survival in CABG patients (hazard ratio 1.22; 95% confidence interval: 1.08 to 1.37). For isolated valvular surgery or combined procedures, AF was not significantly associated with long-term survival (hazard ratio 1.21, 95% confidence interval: 0.92 to 1.58; and hazard ratio 1.15, 95% confidence interval: 0.90 to 1.46, respectively). CONCLUSIONS: Postoperative AF increases late mortality after isolated CABG surgery only. This finding was not statistically confirmed after isolated or combined valvular procedures. Our results draw the attention to possible AF recurrence after hospital discharge, indicating a strict postoperative surveillance.