Nosocomial infections after off-pump coronary artery bypass surgery: frequency, characteristics, and risk factors.

We evaluated the frequency, risk factors, and characteristics of infections in 360 patients after off-pump coronary artery bypass grafting (OPCABG). A prospective study was performed during the period June 2004-October 2005 at Henry Dunant Hospital, Athens, Greece. C-reactive protein (CRP) and procalcitonin were assayed from 222 patients preoperatively, and 1-3 days following OPCABG. Variables independently associated with infection were identified by a multivariable logistic regression model. Eighteen of 360 (5%) patients developed postoperative infections; 1.7% developed superficial wound infection, 1.4% pneumonia, 1.1% bacteremia, 0.3% mediastinitis, and 0.3% intra-aortic balloon pump related infection. The mean increase of CRP and procalcitonin levels in the first two or three days, respectively, after surgery was significantly higher (P<0.05) in patients with infection. Independent risk factors of infection (P<0.05) were history of major nervous system disorder, left ventricular heart failure preoperatively, emergent operation, transfusions of red blood cells during ICU stay, and duration of central venous catheter placement. The identification of risk factors for infection in combination with the appropriate evaluation of the increased CRP and procalcitonin values may help clinicians for the early diagnosis of infection after OPCABG.

Effect of thiazolidinedione therapy on restenosis after coronary stent implantation: a meta-analysis of randomized controlled trials.

BACKGROUND: We sought to review the evidence from the available randomized controlled trials (RCTs) regarding the effect of thiazolidinedione therapy on in-stent restenosis after percutaneous coronary intervention. METHODS: The studies in our meta-analysis were retrieved from search on the PubMed database and from references in relevant articles. Included studies were RCTs that provided comparative data regarding the effectiveness of 6-month pioglitazone or rosiglitazone therapy on the prevention of in-stent restenosis after coronary stent implantation as assessed by quantitative coronary angiography. RESULTS: Five RCTs that included 235 evaluable patients who underwent coronary stent implantation and received a 6-month pioglitazone or rosiglitazone therapy were included in our meta-analysis. Restenosis rate was significantly lower in patients who received thiazolidinedione therapy in addition to standard therapy (3 RCTs, 170 patients, odds ratio 0.29, 95% CI 0.15-0.56, random effects model). Percentage diameter stenosis was significantly lower in the pioglitazone-rosiglitazone arm (3 RCTs, 170 patients, weighted difference in means 14.35, 95% CI 19.99-8.72, random effects model). Minimal lumen diameter of the target lesion was significantly higher in patients who received thiazolidinedione therapy (3 RCTs, 170 patients, weighted difference in means 0.43, 95% CI 0.21-0.65, random effects model). Patients who received thiazolidinediones were significantly less likely to undergo target lesion revascularization due to restenosis (4 RCTs, 197 patients, odds ratio 0.24, 95% CI 0.09-0.61, random effects model). CONCLUSIONS: Our study suggests that thiazolidinedione therapy in patients undergoing coronary stent implantation may be associated with less in-stent restenosis and repeated revascularization. Decisions on clinical use of this therapy must await larger double-blind clinical trials.

Arrhythmias associated with fluoroquinolone therapy.

Fluoroquinolones are widely used and well tolerated antibacterial agents. However, prolongation of the QT interval is an adverse effect associated with the use of fluoroquinolones. According to the available case reports and clinical studies, moxifloxacin carries the greatest risk of QT prolongation from all available quinolones in clinical practice and it should be used with caution in patients with predisposing factors for Torsades de pointes (Tdp). Although gemifloxacin, levofloxacin and ofloxacin are associated with a lower risk of QT prolongation compared with moxifloxacin, they should also be used with caution in patients with risk factors for QT prolongation. Ciprofloxacin appears to be associated with the lowest risk for QT prolongation and the lowest rate of Tdp. The overall risk of Tdp is small with the use of fluoroquinolones. Clinicians can minimise that risk by avoiding prescriptions of multiple medications associated with QT interval prolongation, especially in high-risk patients.

Streptococcus agalactiae infections in non-pregnant adults: single center experience of a growing clinical problem.

BACKGROUND: Group B beta-hemolytic streptococcus (Streptococcus agalactiae) has been traditionally considered a major pathogen in neonates and pregnant women. However, there is accumulating concern about its significance in non-pregnant adults too. MATERIAL/METHODS: To study Streptococcus agalactiae infections in non-pregnant adults in a 354-bed general tertiary center in Athens, Greece, we analyzed retrospectively collected data from patients with Streptococcus agalactiae isolates during a 5-year period. RESULTS: Sixty-nine strains were isolated from specimens of 65 non-pregnant adults (42 women and 23 men). Thirty-four of them were managed as inpatients and 31 as outpatients. Mean age of the 34 inpatients was 57.7 (range 18-84) years. Nineteen (17 women and 2 men) of the 34 inpatients had the organism isolated from urine. Thirteen of these 19 (68.4%) patients had clinical evidence of urinary tract infection (UTI). Streptococcus agalactiae infections were diagnosed in 26 of 34 inpatients. Besides the 13 inpatients with an UTI, 2 had bacteremia of unknown origin, 2 pneumonia, 2 erysipelas, 1 spondylodiscitis, 1 peritonitis, 2 prostatitis, 1 perirectal abscess, 1 testicular abscess, and 1 diabetic foot infection. Underlying conditions of the 26 inpatients possibly predisposing to infections were neoplasia, diabetes mellitus, heart disease, splenectomy, and corticosteroid treatment. CONCLUSIONS: In keeping with results from other recent studies Streptococcus agalactiae was isolated more frequently than previously believed from non-pregnant adults in our study. In addition, our data suggest that Streptococcus agalactiae may be an underestimated cause of UTI in non-pregnant women.

Microbiologically documented nosocomial infections after coronary artery bypass surgery without cardiopulmonary bypass.

OBJECTIVE: This study was undertaken to evaluate the frequency, characteristics, and risk factors of microbiologically documented nosocomial infections after off-pump coronary artery bypass grafting. METHODS: A prospective cohort study was performed at Henry Dunant Hospital, Athens, Greece. It included all adult patients who underwent coronary artery bypass grafting with no valve surgery and without the use of cardiopulmonary bypass during a period of 3 years. Case patients were those with development of microbiologically documented nosocomial infections. Various variables were examined as possible risk factors for nosocomial infections. RESULTS: Twenty-one of 782 studied patients (2.7%) acquired 26 microbiologically documented nosocomial infections after off-pump coronary artery bypass grafting. Eight of 782 studied patients had pneumonia (1.02%), 7 of 782 (0.90%) had bacteremia, 4 of 782 (0.51%) had superficial wound infection at the sternotomy site, 4 of 782 (0.51%) had urinary tract infection, 2 of 782 (0.26%) had mediastinitis, and 1 of 782 (0.13%) had pressure sore infection. Twenty-one infections were monomicrobial, whereas 5 were polymicrobial. All polymicrobial infections were wound infections. There was a statistically significant difference in mortality between patients with and without nosocomial infection (23.8% vs 1.2%, P < .001). Clinical response of the infection to the treatment administered was observed in 21 of 26 episodes (80.8%) in 21 patients. A backward stepwise multivariable logistic regression model showed that independent risk factors (P < .05) associated with development of microbiologically documented nosocomial infection were arterial hypertension, previous vascular surgery, urgent operation, postoperative atrial fibrillation, number of inotropes used during and after operation, transfusion of fresh-frozen plasma during the intensive care unit stay, and intensive care unit stay until development of infection. CONCLUSION: Nosocomial infection after off-pump coronary artery bypass grafting is an uncommon but potentially life-threatening complication. The identification of independent risk factors, including arterial hypertension, associated with development of postoperative infection may help in the development of clinical strategies for the prevention, early diagnosis, and treatment of these infections.

Clinical decision-making based on findings presented in conference abstracts: is it safe for our patients?

Research findings presented in scientific conferences have a considerable direct and indirect impact on decision-making of clinicians. Investigators in various fields of research have examined the possible differences in aims, results, and conclusions between conference abstracts and subsequent corresponding published papers. They documented that differences between data presented in conference abstracts and published papers are frequent and occasionally major. These findings strongly support the position that we should not hurry to incorporate in clinical decision-making data presented at international or national scientific conferences. Instead, we believe that we better serve our patients by waiting at least for the evaluation of potential scientific advances by rigorous peer review.

Frequency, characteristics, and predictors of microbiologically documented nosocomial infections after cardiac surgery.

OBJECTIVE: Nosocomial infections still remain a serious problem in patients undergoing open heart surgery. The objective of this study was to evaluate frequency, characteristics, and predictors of nosocomial infections after cardiac surgery. METHODS: This prospective case-control study was conducted in adult patients who underwent open heart surgery with use of extracorporeal circulation over a period of 16 months. Cases were patients who developed microbiologically documented nosocomial infection. Controls were patients who had open heart surgery within a randomly selected two-month period of the study (defined before the start of the study) and did not develop nosocomial infection. Various variables, available before, during or within the first two days after operation, were examined as possible risk factors of nosocomial infections in bi-variable analysis. Then, variables that were found to be statistically associated with nosocomial infections in the bi-variable analysis were included in a multivariable logistic regression model to identify independent risk factors associated with nosocomial infections after open heart surgery. RESULTS: One hundred and seven of 2122 (5.0%) patients developed microbiologically documented nosocomial infection after open cardiac surgery. The majority of nosocomial infections were respiratory tract infections (45.7%) and central venous catheter-related infections (25.2%). All cause hospital mortality was 16.8% in patients with nosocomial infection and 3.5% in the control group (p=0.005). Out of 20 variables studied as possible risk factors, 12 had a statistically significant association with postoperative infection. History of immunosuppression (OR=3.6, 95% CI 1.2-11.0%), transfusion of more than five red blood cell units in both the operating room and during the first ICU postoperative day (OR=21.2, 95% CI 11.9-37.8%), and development of acute renal failure within the first two days after operation (OR=49.9, 95% CI 22.4-111.0%), were found to be independent predictors of nosocomial infections after cardiac surgery in a multivariable logistic regression model. CONCLUSIONS: Postoperative nosocomial infections are a considerable problem in cardiac surgery patients. The identified independent predictors of nosocomial infection may be useful in identifying those at high risk for development of such infection in cardiac surgery patients.

Research contribution of different world regions in the top 50 biomedical journals (1995-2002).

We evaluated all articles published by different world regions in the top 50 biomedical journals in the database of the Journal Citation Reports-Institute for Scientific Information for the period between 1995 and 2002. The world was divided into 9 regions [United States of America (the U.S.), Western Europe, Japan, Canada, Asia, Oceania, Latin America, and the Caribbean, Eastern Europe, and Africa] based on a combination of geographic, economic and scientific criteria. The number of articles published by each region, the mean impact factor, and the product of the above two parameters were our main indicators. The above numbers were also adjusted for population size, gross national income per capita of each region, and other factors. Articles published from the U.S. made up about two-thirds of all scientific papers published in the top 50 biomedical journals between 1995 and 2002. Western Europe contributed approximately a quarter of the published papers while the remaining one-tenth of articles came from the rest of the world. Canada, however, ranked second when number of articles was adjusted for population size. The U.S. is by far the highest-ranking country/region in publications in the top 50 biomedical journals even after adjusting for population size, gross national product, and other factors. Canada and Western Europe share the second place while the rest of the world is far behind.

Recurrent post-sternotomy mediastinitis.

The use of muscle flaps or omentum flap combined with an appropriate anti-microbial regimen is the treatment of choice for patients with recurrent mediastinitis. Flap closure obliterates the large mediastinal wounds and prevents spreading of the infection to the aorta, heart, including the vascular coronary artery grafts, and other prosthetic materials. In addition, the use of muscle flaps or omentum flap provides the infected tissues with the essential blood supply including good concentration of intravenously administered antibiotics, and leads to early wound closure with sufficient chest stability and respiratory function.

From conference abstract to full paper: differences between data presented in conferences and journals.

BACKGROUND: We studied the type and frequency of differences between data presented in conference abstracts and subsequent published papers in the fields of infectious diseases and microbiology. METHODS: We reviewed all abstracts from the first session of 7 of 15 major research categories presented in the 1999 and 2000 Interscience Conference on Antimicrobial Agents and Chemotherapy. For each selected pair of abstract and related published paper, two independent investigators performed a detailed data comparison. RESULTS: From 190 abstracts reviewed, 68 (36%) were subsequently published as full papers by March 2004. Fifty-two pairs referred to the same study population and period. Differences were found in 30 of 51 pairs, which were further analyzed (point estimate=59%, 95% C.I.: 45-73%). The identified differences were related to both the aims and conclusions of the study (3/30), the study conclusions only (2/30), numbers and/or rates of the studied patients (10/30), numbers or rates of microbiological isolates (9/30), MIC values or K(i) values (5/30), other pharmacological properties of antibiotics (2/30), odds ratio (1/30), and duration of observation (1/30). Some differences were considered major. In bivariable associations, time to publication (from presentation in the conference to publication of the full paper) was associated with identifiable differences between the conference abstract and the full paper (OR=1.76, 95% CI 0.95-3.24/year of delay, P=0.07). CONCLUSIONS: It is reassuring that although we identified several reportable differences, only a very small proportion of studies exhibited differences in their aims and/or conclusions. Researchers may benefit from the above findings in improving the accuracy of presented data.

Estimates of global production in cardiovascular diseases research.

OBJECTIVE: To evaluate the contribution of different world regions in cardiovascular research production. METHODS: The world was divided into 9 regions based on a combination of geographic, economic and scientific criteria. Using the Medline database, we retrieved articles from 77 journals included in the "Cardiac and Cardiovascular Systems" category of the "Journal Citation Reports" database for the period 1995-2002. We then, estimated the total number of publications, their mean impact factor, the product of these two parameters, the research productivity per billion of US dollars spent on research and development, and the research productivity per number of scientists-years in research and development for different world regions. RESULTS: Data on the country of origin for the authors was available for 86,711 out of 87,939 retrieved articles (98.6%). The majority of articles published between 1995-2002 were originated from Western Europe (39.4%) and the USA (37.1%). The USA, Oceania and Canada had the highest mean impact factor of published articles and Eastern Europe had the lowest. The research productivity per unit of expenditure for research and development was found to be significantly higher for Canada compared to the USA and Western Europe while the rate of increase in the number of published articles was higher in Eastern Europe, Latin America and the Caribbean, and Asia. The research contribution of Africa in the number of published articles was notably very low (0.3%). CONCLUSIONS: The data suggest a promising trend: developing world regions, with the important exception of Africa, achieved a higher rate of increase in the number of published articles in the studied period.

Cure of multidrug-resistant Acinetobacter baumannii bacteraemia with continuous intravenous infusion of colistin.

Continuous intravenous colistin (2,000,000 units per 24 h) was administered in a 41-y-old patient with Acinetobacter baumannii bacteraemia, which led to the cure of the infection. The isolated microorganism was a multi-resistant strain (it was sensitive only to colistin). In addition, the patient had developed allergic reactions to previously administered antimicrobial agents of several classes during his hospitalization. Continuous intravenous infusion of colistin proved to be a salvage regimen, which led to cure of a bacteraemia due to a multi-resistant isolate, without showing any allergic cross-reactivity with other antibiotics.