A role for IL-16 in the cross-talk between dendritic cells and T cells

Dendritic cells (DCs) in the periphery capture and process Ags, migrate to lymphoid organs, and initiate immune responses in T cells. IL-16, the soluble ligand for CD4, is a potent chemoattractant for CD4+ T cells, eosinophils, and monocytes and is mainly derived from activated T cells. Because migration is a fundamental property of DCs, we asked whether IL-16 induces chemotaxis in DCs and whether DCs are a source of IL-16. DCs were generated by culture of monocytes in IL-4 and GM-CSF for 6 days and subsequently highly purified employing magnetic beads. Migration was assayed by nitrocellulose and polycarbonate filter-based assays, and distinction of chemotaxis and chemokinesis was performed by a checkerboard analysis. Messenger RNA and protein data revealed constitutive expression and release of IL-16 by day-6 DCs. Gradients of rIL-16 induced a chemotactic response of DCs. Furthermore, the chemotactic activity of DC supernatant toward DCs themselves and T cells was mainly due to IL-16, because the addition of neutralizing Abs completely abrogated the migratory response. However, after induction of maturation by the addition of TNF-alpha and PGE2 DCs, neither expressed IL-16 mRNA nor produced IL-16 protein. We conclude that IL-16 may play a role in the trafficking of DCs and may be a major chemotactic signal from DCs toward themselves and toward T cells.

Multivariate prediction of in-hospital mortality after percutaneous coronary interventions in 1994-1996. Northern New England Cardiovascular Disease Study Group

OBJECTIVES

Using recent data, we sought to identify risk factors associated with in-hospital mortality among patients undergoing percutaneous coronary interventions.

BACKGROUND

The ability to accurately predict the risk of an adverse outcome is important in clinical decision making and for risk adjustment when assessing quality of care. Most clinical prediction rules for percutaneous coronary intervention (PCI) were developed using data collected before the broader use of new interventional devices.

METHODS

Data were collected on 15,331 consecutive hospital admissions by six clinical centers. Logistic regression analysis was used to predict the risk of in-hospital mortality.

RESULTS

Variables associated with an increased risk of in-hospital mortality included older age, congestive heart failure, peripheral or cerebrovascular disease, increased creatinine levels, lowered ejection fraction, treatment of cardiogenic shock, treatment of an acute myocardial infarction, urgent priority, emergent priority, preprocedure insertion of an intraaortic balloon pump and PCI of a type C lesion. The receiver operating characteristic area for the predicted probability of death was 0.88, indicating a good ability to discriminate. The rule was well calibrated, predicting accurately at all levels of risk. Bootstrapping demonstrated that the estimate was stable and performed well among different patient subsets.

CONCLUSIONS

In the current era of interventional cardiology, accurate calculation of the risk of in-hospital mortality after a percutaneous coronary intervention is feasible and may be useful for patient counseling and for quality improvement purposes.

Outcomes of high-dose chemotherapy and autologous stem-cell transplantation in stage IIIB inflammatory breast cancer

PURPOSE

To evaluate the disease-free survival (DFS) and overall survival (OS), prognostic factors, and treatment-related mortality of women with stage IIIB inflammatory breast cancer (IBC) treated with combined modality therapy (CMT) and high-dose chemotherapy (HDCT) with autologous stem-cell transplantation.

PATIENTS AND METHODS

Between 1989 and 1997, 47 consecutive patients with stage IIIB IBC were treated with CMT and HDCT and were the subject of this retrospective analysis. Chemotherapy was administered to all patients before and/or after definitive surgery. Neoadjuvant and adjuvant chemotherapy was administered to 33 and 34 patients, respectively, and 20 patients received both. All patients received HDCT with autologous stem-cell transplantation, and 41 patients received locoregional radiation therapy. Tamoxifen was prescribed to patients with estrogen receptor (ER)-positive cancer.

RESULTS

The mean duration of follow-up from diagnosis was 30 months (range, 6 to 91 months) and from HDCT was 22 months (range, 0.5 to 82 months). At 30 months, the Kaplan-Meier estimates of DFS and OS from diagnosis were 57.7% and 59.1%, respectively. At 4 years, the Kaplan-Meier estimates of DFS and OS from diagnosis were 51.3% and 51.7%, respectively. In a multivariate analysis, the only factors associated with better survival were favorable response to neoadjuvant chemotherapy (P =.04) and receipt of tamoxifen (P =.06); however, the benefit of tamoxifen was only demonstrated in patients with ER-positive breast cancer. At last follow-up, 28 patients (59. 6%) were alive and disease-free. Seventeen patients (36.2%) developed recurrent breast cancer. Seventeen patients died: 15 from disease recurrence and two (4.2%) from treatment-related mortality due to HDCT.

CONCLUSION

In this analysis, the early results of treatment with CMT and HDCT compare favorably with other series of patients with stage IIIB IBC treated with CMT alone. These outcomes must be confirmed with longer follow-up and controlled studies.

Cause of in-hospital death in 12,232 consecutive patients undergoing percutaneous transluminal coronary angioplasty. The Northern New England Cardiovascular Disease Study Group

BACKGROUND

Some deaths after percutaneous coronary angioplasty (PTCA) occur in high-risk situations (eg, shock), whereas others are unexpected and related to procedural complications. To better describe the epidemiologic causes of death after PTCA, we undertook a systematic review of all in-hospital PTCA deaths in Northern New England from 1990 to 1993.

METHODS

The medical records of 121 patients who died during their acute hospitalization for PTCA were reviewed with a standardized data extraction tool to determine a mode of death (eg, low output failure, arrhythmia, respiratory failure) and a circumstance of death (eg, death attributable to a procedural complication, preexisting acute cardiac disease). Any death not classified as a procedural complication was reviewed by a committee and the circumstance of death assigned by a majority rule.

RESULTS

Low-output failure was the most common mode of death occurring in 80 (66.1%) of 121 patients. Other modes of death included ventricular arrhythmias (10.7%), stroke (4.1%), preexisting renal failure (4.1%), bleeding (2.5%), ventricular rupture (2.5%), respiratory failure (2.5%), pulmonary embolism (1.7%), and infection (1.7%). The circumstance of death was a procedural complication in 65 patients (53.7%) and a preexisting acute cardiac condition in 41 patients (33.9%). Women were more likely to die of a procedural complication than were men.

CONCLUSION

Procedural complications account for half of all post-PTCA deaths and are a particular problem for women. Other deaths are more directly related to patient acuity or noncardiac, comorbid conditions. Understanding why women face an increased risk of procedural complications may lead to improved outcomes for all patients.

Glutamyl hydrolase: properties and pharmacologic impact

Glutamyl hydrolase cleaves the poly-gamma-glutamate chain folate and antifolate poly-gamma-glutamates. Its cellular location is lysosomal with large amounts of the enzyme constitutively secreted. The highest levels of glutamyl hydrolase mRNA in humans is found in the liver and kidney. Baculovirus-expressed human enzyme has been used to evaluate the method of hydrolysis of methotrexate-gamma-glu4 and MTA-gamma-glu4. In both cases, the substrates are hydrolyzed by removal of the outer two gamma-glutamate linkages, yielding glu and gamma-glu2 as the glutamate products. Cell lines resistant to 5,10-dideazatetrahydrofolate (lometrexol) have sevenfold higher activities of glutamyl hydrolase. These cultures have a 60% to 90% reduced amount of antifolate polygamma-glutamates and 30% reduced folyl poly-gamma-glutamates. These results suggest the possibility of using glutamyl hydrolase to favorably modulate the activity of antifolate therapy.

Computer-controlled bipolar endotubal sterilization is successful in a rabbit model

OBJECTIVE

To determine the efficacy of a computer-controlled bipolar endotubal catheter system designed to accomplish safe, effective, and inexpensive female sterilization in preventing pregnancy in a rabbit model.

DESIGN

Prospective controlled study.

SETTING

University animal care facility.

ANIMAL(S)

Sixty healthy virginal female New Zealand white rabbits.

INTERVENTION(S)

Rabbits were assigned to the following groups: [1] endotubal radiofrequency minimal energy (95 degrees C) treatment; [2] endotubal radiofrequency maximal energy (105 degrees C) treatment; [3] endouterine radiofrequency (105 degrees C) treatment; [4] nonsurgical control; [5] laparotomy-only control; [6] endotubal radio-frequency sham control; and [7] external Kleppinger forceps bipolar cautery control. Rabbits were mated at 4 or 12 weeks after treatment.

MAIN OUTCOME MEASURE(S)

Pregnancy outcomes in treated animals and nontreated controls.

RESULT(S)

No pregnancies were observed in any of the uterine horns in which minimal or maximal energy was delivered to the fallopian tubes or uterus, although pregnancy occurred in one horn as a result of the delivery of energy below the radiofrequency minimum of 95 degrees C. The outcomes of the treatment groups were significantly different from those of the nonsurgical and sham surgical control groups.

CONCLUSION(S)

With adequate tissue heating, 100% sterilization efficacy was achieved with a new, computer-controlled bipolar catheter, whereas pregnancies occurred in all untreated control groups. If human studies support these results, the goal of a safe, effective means of transcervical sterilization may be realized.

Efficacy and safety of clonazepam in refractory neurally mediated syncope

Neurally mediated syncope is a complex syndrome that is often difficult to manage using currently available treatment strategies. The efficacy and safety of clonazepam was evaluated in 35 patients with refractory neurally mediated syncope. All patients had syncope (n = 33) or disabling presyncope (n = 2) and a positive head-up tilt table test (HUTT) despite treatment with one or more of the following therapies: beta-blocker, high-salt diet, fludrocortisone, elastic compression stockings, and disopyramide. Clonazepam was initiated at 0.5 mg/day and titrated in 0.25-0.5 mg/day increments for symptom control. Early (first 8 weeks) symptomatic response was achieved in 31 of 35 (89%) patients. Early HUTT reverted to negative in 29 of 35 (83%) patients. Two patients discontinued clonazepam during early follow-up due to side effects. Thirty-three patients received long-term clonazepam therapy. Twenty-five patients had late HUTT with 21 remaining negative. Of the eight patients who did not have late HUTT, one patient discontinued clonazepam prior to HUTT due to side effects. Seven patients refused late HUTT. All seven patients achieved symptomatic control on clonazepam with two requiring dose titration. Of the 21 patients with a negative late HUTT, 18 achieved symptomatic control with two of these patients requiring dose titration. Two patients who had only partial symptom control despite dose titration achieved total symptomatic control with the addition of disopyramide and beta-blockers. Two patients with a negative late HUTT discontinued clonazepam due to side effects. One patient had been symptomatically controlled while the other had recurrent symptoms with dose limiting side effects occurring after clonazepam dose titration. In the 4 patients with a positive late HUTT, 2 patients were symptomatically controlled, 1 patients required combination therapy with a beta-blocker to achieve symptomatic control, and 1 patient discontinued therapy due to side effects. Overall, 29 of 35 (83%) patients continue to receive clonazepam with symptom control. Based on intention-to-treat HUTT results, 21 of 35 (60%) patients were responders. Four patients required clonazepam dose titration and three required combination therapy with clonazepam plus disopyramide and/or a beta-blocker to achieve control. Clonazepam was discontinued in 6 patients, 5 for side effects and 1 following a transient ischemic attack. Clonazepam appears to be an effective therapeutic alternative in patients with refractory neurally mediated syncope. Based on our preliminary findings, a placebo controlled evaluation of clonazepam in neurally mediated syncope is warranted.

Perioperative predictors of extubation failure and the effect on clinical outcome after cardiac surgery

OBJECTIVES

To determine perioperative predictors of extubation failure (requirement for reintubation and mechanical ventilation after prior successful weaning from ventilator support and extubation) after cardiac surgery and the effect on clinical outcome.

DESIGN

Cohort study.

SETTING

A tertiary-care, 54-bed, cardiothoracic intensive care unit (ICU).

PATIENTS

ICU admissions (n = 11,330) after cardiac surgery over a 42-month period.

INTERVENTIONS

Collection of preoperative, operative, and ICU data from a database.

MEASUREMENTS AND MAIN RESULTS

Frequency of extubation failure, total duration of mechanical ventilation, length of stay in ICU and hospital, and death. There were 748 (6.6%) patients who were weaned from mechanical ventilation after cardiac surgery and required reintubation and ventilator support. The predictors of extubation failure were: age of > or =65 yrs; inpatient hospitalization before surgery; arterial vascular disease; chronic obstructive pulmonary disease; pulmonary hypertension; severe left ventricular dysfunction; cardiac shock; hematocrit of < or =34%; blood urea nitrogen of > or =24 mg/dL; serum albumin concentration of < or =4.0 g/dL (< or =40.0 g/ L); systemic oxygen delivery of < or =320 mL/min/m2; redo operation; surgical procedures involving the thoracic aorta; transfusion of blood products of > or =10 units; and cardiopulmonary bypass time of > or =120 mins. Extubation failure prolonged the length of total mechanical ventilation, as well as ICU and hospital stay, independent of the frequency of organ dysfunction or nosocomial infections but did not increase the risk of death after cardiac surgery.

CONCLUSIONS

Extubation failure after cardiac surgery is uncommon. Although extubation failure increased the utilization of ICU and hospital resources, it did not affect mortality after cardiac surgery. Protocols for early extubation and ICU discharge should be modified in the presence of certain preoperative and operative predictors of extubation failure to avoid unnecessary increase in the cost of care after cardiac surgery.

Recombinant expression and localization of Schistosoma mansoni cathepsin L1 support its role in the degradation of host hemoglobin

Cysteine proteinases expressed by schistosomes appear to play key roles in the digestion of host hemoglobin, the principal source of amino acid nutrients utilized by these parasites. We have shown previously that the predominant cysteine proteinase activity in soluble extracts and excretory/secretory (ES) products of adults of Schistosoma mansoni and S. japonicum is cathepsin L-like in its substrate specificity. However, biochemical analysis of the cathepsin L activity in extracts and ES products of schistosomes has been complicated by the presence of at least two distinct forms of schistosome cathepsin L, termed SmCL1 and SmCL2. We now report the purification and enzyme characteristics of active, recombinant SmCL1 which was obtained by transforming Saccharomyces cerevisiae with an expression plasmid encoding the preproenzyme of SmCL1. Recombinant SmCL1 was secreted by the transformed yeast into the culture media from which it was purified by gel filtration and ion-exchange chromatography. The purified enzyme exhibited substrate specificity against synthetic peptidyl substrates (e.g., Boc-Val-Leu-Lys-NHMec and Z-Phe-Arg-NHMec; kcat/Km = 17.25 and 6.24 mM-1 s-1, respectively) and against gelatin and hemoglobin, characteristic of cathepsin L. Immunoblot analysis using antiserum raised against recombinant SmCL1 demonstrated that native SmCL1 of 33 kDa was present in ES products and soluble extracts of S. mansoni. Using this antiserum and thin tissue sections, we localized the native SmCL1 to the gastrodermis and to the tegument of adult schistosomes. Recombinant SmCL1 was capable of degrading human hemoglobin at pH 4.0 to 4.5 but not higher, suggesting that denaturation of hemoglobin by low pH, as found in the cecum of the adult schistosome, may be necessary for its catalysis by cathepsin L and other gut-associated proteinases. Together, these results support a role for SmCL1 in the degradation of host hemoglobin within the gut of the schistosome.

Assessment of regional wall motion abnormalities with real-time 3-dimensional echocardiography

Accurate characterization of regional wall motion abnormalities requires a thorough evaluation of the entire left ventricle (LV). Although 2-dimensional echocardiography is frequently used for this purpose, the inability of tomographic techniques to record the complete endocardial surface is a limitation. Three-dimensional echocardiography, with real-time volumetric imaging, has the potential to overcome this limitation by capturing the entire volume of the LV and displaying it in a cineloop mode. The purpose of this study was to assess the feasibility of using real-time 3-dimensional (RT3D) echocardiography to detect regional wall motion abnormalities in patients with abnormal LV function and to develop a scheme for the systematic evaluation of wall motion by using the 3-dimensional data set. Twenty-six patients with high-quality 2-dimensional echo images and at least 1 regional wall motion abnormality were examined with RT3D echocardiography. For 2-dimensional echocardiography, wall motion was analyzed with a 16-segment model and graded on a 4-point scale from normal (1) to dyskinetic (4), from which a wall motion score index was calculated. Individual segments were then grouped into regions (anterior, inferoposterior, lateral, and apical) and the number of regional wall motion abnormalities was determined. The RT3D echocardiogram was recorded as a volumetric, pyramid-shaped data set that contained the entire LV. Digital images, consisting of a single cardiac cycle cineloop, were analyzed off-line with a computerized display of the apical projection. Two intersecting orthogonal apical projections were simultaneously displayed in cineloop mode, each independently tilted to optimize orientation and endocardial definition. The 2 planes were then slowly rotated about the major axis to visualize the entire LV endocardium. Wall motion was then graded in 6 equally spaced views, separated by 30 degrees, yielding 36 segments per patient. A higher percentage of segments were visualized with 2-dimensional versus RT3D echocardiography (97% vs 83%, respectively, P <.001). With the use of the 2-dimensional echocardiographic results as the standard, RT3D echocardiography detected 55 (96%) of 57 regional wall motion abnormalities. Analysis of the RT3D echocardiograms resulted in 3 false-negative and 5 false-positive findings. The total number of regional wall motion abnormalities was correctly classified by RT3D echocardiography in 19 (73%) of 26 patients. RT3D echocardiography detected 11 of 13 anterior, 19 of 20 inferoposterior, 9 of 9 lateral, and 15 of 15 apical wall motion abnormalities. An excellent correlation was found between the 2 techniques for assessment of the regional wall motion score index (r = 0.89, P <.001). This initial clinical study demonstrates the feasibility and potential advantages of RT3D echocardiography for the assessment of regional LV function. Compared with 2-dimensional echocardiography, this new method permits recording of the entire LV in a single beat, allowing the extent and location of the regional wall motion abnormalities to be determined.

Infective endocarditis due to Staphylococcus aureus: 59 prospectively identified cases with follow-up

Fifty-nine consecutive patients with definite Staphylococcus aureus infective endocarditis (IE) by the Duke criteria were prospectively identified at our hospital over a 3-year period. Twenty-seven (45.8%) of the 59 patients had hospital-acquired S. aureus bacteremia. The presumed source of infection was an intravascular device in 50.8% of patients. Transthoracic echocardiography (TTE) revealed evidence of IE in 20 patients (33.9%), whereas transesophageal echocardiography (TEE) revealed evidence of IE in 48 patients (81.4%). The outcome for patients was strongly associated with echocardiographic findings: 13 (68.4%) of 19 patients with vegetations visualized by TTE had an embolic event or died of their infection vs. five (16.7%) of 30 patients whose vegetations were visualized only by TEE (P < .01). Most patients with S. aureus IE developed their infection as a consequence of a nosocomial or intravascular device-related infection. TEE established the diagnosis of S. aureus IE in many instances when TTE was nondiagnostic. Visualization of vegetations by TTE may provide prognostic information for patients with S. aureus IE.

Employment after coronary angioplasty or coronary bypass surgery in patients employed at the time of revascularization

BACKGROUND

Patients who undergo coronary angioplasty have a shorter convalescence than those who undergo coronary bypass surgery. This may improve subsequent employment.

OBJECTIVE

To compare employment patterns after coronary angioplasty or surgery.

DESIGN

Multicenter, randomized clinical trial.

SETTING

Seven tertiary care hospitals.

PATIENTS

409 employed patients with multivessel coronary artery disease.

INTERVENTION

Coronary bypass surgery or balloon angioplasty.

MEASUREMENTS

Time to return to work and time spent working during 4 years of follow-up.

RESULTS

Patients who underwent angioplasty returned to work 6 weeks sooner than patients who underwent coronary bypass surgery (P < 0.001), but long-term employment did not differ significantly (P > 0.2). Long-term employment was significantly lower among patients who were 60 to 64 years of age (P < 0.001), those who worked less than full-time at study entry (P < 0.001), and those who had less formal education (P = 0.005). Patients with only one source of health insurance were more likely to continue working (P = 0.005).

CONCLUSIONS

Faster recovery after angioplasty speeds return to work but does not improve long-term employment, which is primarily associated with nonmedical factors.

The effects of preoperative therapy with angiotensin-converting enzyme inhibitors on clinical outcome after cardiovascular surgery

OBJECTIVE

To determine the effect of preoperative therapy with angiotensin-converting enzyme (ACE) inhibitors on clinical outcome after cardiovascular surgery.

STUDY

Inception cohort.

SETTING

A tertiary care 54-bed cardiothoracic ICU.

PATIENTS

All admissions to an ICU over a 42-month period after cardiovascular surgery.

INTERVENTION

Extraction of preoperative, operative, and ICU data from a database.

OUTCOME MEASURES

Incidence of acute organ dysfunction, length of mechanical ventilation, ICU stay, and death after cardiovascular surgery.

RESULTS

The study cohort consisted of four groups: normal or moderately impaired left ventricular function control (group A, n=6,400); normal or moderately impaired left ventricular function treated with ACE inhibitors (group B, n=1,375); severe left ventricular dysfunction control (group C, n=1,905); and severe left ventricular dysfunction treated with ACE inhibitors (group D, n=1,650). The incidence of three or more organ dysfunction was similar on comparison of group A vs group B (5% vs 6%) or group C vs group D (15% vs 13%). There were no differences in the total duration of mechanical ventilation or length of stay in the ICU in group A vs group B or group C vs group D. Death occurred in 2% of groups A and B, and at 6% in groups C and D. Preoperative severe left ventricular dysfunction in both groups C and D was associated with an increased incidence of three or more organ dysfunction, duration of mechanical ventilation, length of stay in ICU, and death after surgery. Multivariate analysis indicated that therapy with ACE inhibitors did not affect the clinical outcome after cardiovascular surgery.

CONCLUSION

Preoperative therapy with ACE inhibitors did not influence the clinical outcome after cardiac surgery. It is unlikely that therapy with ACE inhibitors can alter the clinical sequelae of cardiopulmonary bypass and cardiac surgical procedures performed in high-risk patients because of underlying severe left ventricular dysfunction.

Perioperative predictors of acute cholecystitis after cardiovascular surgery

OBJECTIVE

To determine the incidence, diagnostic features, and perioperative predictors of acute cholecystitis after cardiovascular surgery.

DESIGN

Inception cohort study.

SETTING

A tertiary care 54-bed cardiothoracic ICU.

PATIENTS

All patients admitted to an ICU after cardiovascular surgery during a 42-month period.

INTERVENTION

Collection of relevant preoperative, operative, and ICU data from a database and medical charts.

PRIMARY OUTCOME

Postoperative acute cholecystitis (AC).

RESULTS

Out of 11,330 admissions, 876 patients stayed in the ICU more than 7 days and 30 of them (3%) developed postoperative AC. AC was diagnosed a median of 26 days after cardiovascular surgery (interquartile range, 11 to 41 days). All patients with AC developed at least two criteria of the systemic inflammatory response syndrome (SIRS), and 16 of them (53%) were vasopressor-dependent on the day of diagnosis. Trends in biochemical testing of liver function were not diagnostic for AC. Death occurred in seven of 17 patients (41%) who underwent cholecystectomy, three of nine patients (33%) treated with percutaneous cholecystostomy, and one of four patients (25%) treated conservatively (p=not significant). Specific earlier predictors of AC were arterial vascular disease, preoperative oxygen delivery less than 430 mL/min x m2, longer times on cardiopulmonary bypass, surgical re-exploration, ICU course complicated by cardiac arrhythmia, mechanical ventilation > or = 3 days, bacteremia, and nosocomial infections.

CONCLUSION

The incidence of AC is low after cardiovascular surgery. Although SIRS and hemodynamic instability were common at the time of diagnosis, the delayed occurrence and lack of specificity of these features for AC limited their utility for early diagnosis. Specific predictors of AC should be sought in the ICU setting to identify patients who are at risk for AC after cardiovascular surgery. When identified, such predictors can prompt earlier diagnosis and treatment. Further evaluation of the selection criteria for different treatment options is needed in order to decrease the morbidity and mortality associated with AC.

Controlled radiofrequency endotubal sterilization

STUDY OBJECTIVE

A safe, effective, inexpensive method of transcervical tubal sterilization could have a major impact on women's health. In this study, we evaluated the efficacy of a new radiofrequency catheter prototype designed for endotubal sterilization using animal models.

SETTING

Animal research laboratory.

DESIGN

Prospective observational study.

METHOD

The optimal energy delivery to create a complete circumferential transmural thermal lesion in the tube was determined in 114 in vitro acute studies using porcine and bovine fallopian tubes. A study was then initiated with eight mini-pigs. Thirty-four lesions were made in the fallopian tubes using computer-controlled power delivery. Three weeks later the animals were euthanized and evaluated.

MEASUREMENTS AND MAIN RESULTS

A hydrosalpinx was evident in 8/11 of the tubes with separate proximal and distal cautery, implying occlusion at each of these sites. Complete occlusion of the tubes was seen at 12/22 sites evaluated by histology. Narrowing was seen in 9/22, and 1/22 was open.

CONCLUSION

The endotubal cautery prototype creates a reproducible lesion, but did not always cause complete closure of the tube in this preliminary study. However, based on our results, we hypothesize that a radiofrequency catheter can be developed for minimally invasive transcervical sterilization.

Real-time three-dimensional echocardiography for determining right ventricular stroke volume in an animal model of chronic right ventricular volume overload

BACKGROUND

The lack of a suitable noninvasive method for assessing right ventricular (RV) volume and function has been a major deficiency of two-dimensional (2D) echocardiography. The aim of our animal study was to test a new real-time three-dimensional (3D) echo imaging system for evaluating RV stroke volumes.

METHODS AND RESULTS

Three to 6 months before hemodynamic and 3D ultrasonic study, the pulmonary valve was excised from 6 sheep (31 to 59 kg) to induce RV volume overload. At the subsequent session, a total of 14 different steady-state hemodynamic conditions were studied. Electromagnetic (EM) flow probes were used for obtaining aortic and pulmonic flows. A unique phased-array volumetric 3D imaging system developed at the Duke University Center for Emerging Cardiovascular Technology was used for ultrasonic imaging. Real-time volumetric images of the RV were digitally stored, and RV stroke volumes were determined by use of parallel slices of the 3D RV data set and subtraction of end-systolic cavity volumes from end-diastolic cavity volumes. Multiple regression analyses showed a good correlation and agreement between the EM-obtained RV stroke volumes (range, 16 to 42 mL/beat) and those obtained by the new real-time 3D method (r=0.80; mean difference, -2.7+/-6.4 mL/beat).

CONCLUSIONS

The real-time 3D system provided good estimation of strictly quantified reference RV stroke volumes, suggesting an important application of this new 3D method.

Perioperative determinants of morbidity and mortality in elderly patients undergoing cardiac surgery

OBJECTIVE

To determine perioperative predictors of morbidity and mortality in patients > or =75 yrs of age after cardiac surgery.

DESIGN

Inception cohort study.

SETTING

A tertiary care, 54-bed cardiothoracic intensive care unit (ICU).

PATIENTS

All patients aged > or =75 yrs admitted over a 30-month period for cardiac surgery.

INTERVENTION

Collection of data on preoperative factors, operative factors, postoperative hemodynamics, and laboratory data obtained on admission and during the ICU stay.

MEASUREMENTS AND MAIN RESULTS

Postoperative death, frequency rate of organ dysfunction, nosocomial infections, length of mechanical ventilation, and ICU stay were recorded. During the study period, 1,157 (14%) of 8,501 patients > or =75 yrs of age had a morbidity rate of 54% (625 of 1,157 patients) and a mortality rate of 8% (90 of 1,157 patients) after cardiac surgery. Predictors of postoperative morbidity included preoperative intraaortic balloon counterpulsation, preoperative serum bilirubin of >1.0 mg/dL, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >120 mins (aortic cross-clamp time of >80 mins), return to operating room for surgical exploration, heart rate of >120 beats/min, requirement for inotropes and vasopressors after surgery and on admission to the ICU, and anemia beyond the second postoperative day. Predictors of postoperative mortality included preoperative cardiac shock, serum albumin of <4.0 g/dL, systemic oxygen delivery of <320 mL/ min/m2 before surgery, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >140 mins (aortic cross-clamp time of >120 mins), subsequent return to the operating room for surgical exploration, mean arterial pressure of <60 mm Hg, heart rate of >120 beats/min, central venous pressure of >15 mm Hg, stroke volume index of <30 mL/min/m2, requirement for inotropes, arterial bicarbonate of <20 mmol/L, plasma glucose of >300 mg/dL after surgery, and anemia beyond the second postoperative day. During the study period, the study cohort used 6,859 (21.5%) ICU patient-days out of a total 31,867 ICU patient-days. Nonsurvivors used 2,023 (30%) ICU patient-days and patients with morbidity used 5,903 (86%) ICU patient-days.

CONCLUSIONS

Severe underlying cardiac disease (including shock, requirement for mechanical circulatory support, hypoalbuminemia, and hepatic dysfunction), intraoperative blood loss, surgical reexploration, long ischemic times, immediate postoperative cardiovascular dysfunction, global ischemia and metabolic dysfunction, and anemia beyond the second postoperative day predicted poor outcome in the elderly after cardiac surgery. Postoperative morbidity and mortality disproportionately increased the utilization of intensive care resources in elderly patients. Future efforts should focus on preoperative selection criteria, improvement in surgical techniques, perioperative therapy to ameliorate splanchnic and global ischemia, and avoidance of anemia to improve the outcome in the elderly after cardiac surgery.

Clinical utility of troponin T levels and echocardiography in the emergency department

We investigated the clinical utility of cardiac troponin T (TnT) and echocardiography in the emergency department to predict subsequent in-hospital diagnosis and adverse cardiac events. TnT is a cardiac-specific protein released during cell injury such as that following acute myocardial inFarction (MI). Unlike creatine kinase-MB isoenzymes, TnT is increased in a subset of patients with unstable angina, and these may be at higher risk for subsequent cardiac events. Echocardiography is a useful noninvasive imaging technique for the assessment of ischemic heart disease in acute care settings because of its mobility and rapid results. Serial TnT determinations and echocardiographic images were prospectively evaluated in 100 patients with chest discomfort and admitted to the hospital. Serum was obtained for CKMB and TnT on presentation to the emergency department and 4, 8, 16 and 24 hours later. TnT was considered increased when at values greater than 0.1 microg/L. Echocardiograms were recorded on videotape in the emergency department and images reviewed in a blinded fashion for wall-motion abnormalities. When available, current echocardiographic results were compared with previous results to determine whether a new wall-motion abnormality was present. Of the 100 patients (57 men, 43 women), TnT was increased in 21 of 21 with acute MI and 15 of 41 with unstable angina. One of the 38 patients with stable angina had an increased TnT value and died 5 months later of a noncardiac cause. Ninety percent of patients who sustained acute MI had a TnT increase detected within 4 hours of presentation. Fifteen of 18 patients with acute MI and 9 of 37 patients with unstable angina had a new wall-motion abnormality on echocardiography. The combination of TnT levels with echocardiography yielded a positive predictive value of 84% and a negative predictive value of 90% for adverse cardiac events in the follow-up population, which was more accurate than either test analyzed separately. TnT and echocardiography are useful tests in emergency department triage of unstable coronary syndromes. Both tests are predictive of discharge diagnosis and follow-up events. However, the combined utility of TnT levels and echocardiographic imaging is a more powerful predictor of adverse cardiac events than isolated results.

Perceived risks associated with mental illness: beyond homicide and suicide

This paper presents an exploratory study of factors of perceived risk related to people who experience serious mental illness. The study focuses upon four stakeholder groups: service users, their carers, mental health professionals and the general public. The development of a questionnaire to examine risk perceptions is described along with the data collection techniques employed in the study. A large number of data sets (n = 1076) was obtained from the four groups of stakeholders (n = 550). Factor analysis of the data produced six factors of perceived risk: underclass, medical disempowerment, threat, vulnerability, self-harm and dependency. This suggests that stakeholders have a wider perception of risk than perceptions defined through current policy. These factors are subsequently examined in relation to a range of independent variables of which gender is the most significant variable in the perception of risk. The findings support results from studies of other forms of risk where women have been found to perceive risks greater than men.

Stress echocardiography: recommendations for performance and interpretation of stress echocardiography. Stress Echocardiography Task Force of the Nomenclature and Standards Committee of the American Society of Echocardiography

Cardiovascular stress testing remains the mainstay of provocative evaluation for patients with known or suspected coronary artery disease. Stress echocardiography has become a valuable means of cardiovascular stress testing. It plays a crucial role in the initial detection of coronary disease, in determining prognosis, and in therapeutic decision making. The purpose of this document is to outline the recommended methodology for stress echocardiography with respect to personnel and equipment as well as the clinical use of this recently developed technique. Specific limitations will also be discussed.