Örjan Friberg

SWEDEHEART Annual Report 2012

Abstract The Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) supports continuous monitoring and improvement of care for coronary artery disease, catheter-based and surgical coronary interventions, secondary prevention as well as catheter based and surgical valve intervention, by providing extensive data on base-line, diagnostic, procedural and outcome variables. Design. This national quality registry collects information from all Swedish hospitals treating patients with acute coronary artery disease and all patients undergoing coronary angiography, catheter-based interventions or heart surgery. Combination with other national mandatory official registries enables complete follow-up of all individuals regarding myocardial infarction, new interventional procedures, death and all-cause hospitalizations. The registry is governed by an independent steering committee and funded by the Swedish National Health care provider. The software is developed by Uppsala Clinical Research Center. Results. The SWEDEHEART Quality Index reflects overall quality of care for coronary artery disease including secondary prevention. In comparison with 2011, an improvement of the index occurred in 2012 overall. There was however, still a wide range in performance between individual centers, emphasizing the need for continuous monitoring of quality of care at a national as well as on a center level.

Incidence, microbiological findings and clinical presentation of sternal wound infections after cardiac surgery with and without local gentamicin prophylaxis

Sternal wound infection (SWI) is a serious complication after cardiac surgery. In a previous randomized controlled trial, the addition of local collagen-gentamicin in the sternal wound before wound closure was found to significantly reduce the incidence of postoperative wound infections compared with the routine intravenous prophylaxis of isoxazolyl-penicillin only. The aims of the present study were to analyse the microbiological findings of the SWIs from the previous trial as well as to correlate these findings with the clinical presentation of SWI. Differences in clinical presentation of SWIs, depending on the causative agent, could be identified. Most infections had a late, insidious onset, and the majority of these were caused by staphylococci, predominantly coagulase-negative staphylococci. The clinically most fulminant infections were caused by gram-negative bacteria and presented early after surgery. Local administration of gentamicin reduced the incidence of SWIs caused by all major, clinically important bacterial species. Propionibacterium acnes was identified as a possible cause of SWI and may be linked to instability in the sternal fixation. There was no indication of an increase in the occurrence of gentamicin-resistant bacterial isolates in the treatment group. Furthermore, the addition of local collagen-gentamicin reduced the incidence of SWIs caused by methicillin-resistant coagulase-negative staphylococci. This technique warrants further evaluation as an alternative to prophylactic vancomycin in settings with a high prevalence of methicillin-resistant Staphylococcus aureus.

Collagen-gentamicin implant for prevention of sternal wound infection; long-term follow-up of effectiveness

In a previous randomized controlled trial (LOGIP trial) the addition of local collagen-gentamicin reduced the incidence of postoperative sternal wound infections (SWI) compared with intravenous prophylaxis only. Consequently, the technique with local gentamicin was introduced in clinical routine at the two participating centers. The aim of the present study was to re-evaluate the technique regarding the prophylactic effect against SWI and to detect potential shifts in causative microbiological agents over time. All patients in this prospective two-center study received prophylaxis with application of two collagen-gentamicin sponges between the sternal halves in addition to routine intravenous antibiotics. All patients were followed for 60 days postoperatively. From January 2007 to May 2008, 1359 patients were included. The 60-day incidences of any SWI was 3.7% and of deep SWI 1.5% (1.0% mediastinitis). Both superficial and deep SWI were significantly reduced compared with the previous control group (OR=0.34 for deep SWI, P<0.001). There was no increase in the absolute incidence of aminoglycoside resistant agents. The majority of SWI were caused by coagulase-negative staphylococci (CoNS). The incidence of deep SWI caused by Staphylococcus aureus was 0.07%. The results indicate a maintained effect of the prophylaxis over time without absolute increase in aminoglycoside resistance. (ClinicalTrials.gov NCT00484055).

Triclosan-coated sutures reduce surgical site infection after open vein harvesting in coronary artery bypass grafting patients: a randomized controlled trial †

OBJECTIVES The incidence of surgical site infection (SSI) after open vein harvesting in coronary artery bypass grafting (CABG) patients ranges in different studies between 2 and 20%. Triclosan is an antibacterial substance that reduces the growth of bacteria by inhibiting fatty acid synthesis. We hypothesized that wound closure with triclosan-coated sutures would reduce SSI after open vein harvesting. METHODS An investigator-initiated prospective randomized double-blind single-centre study was performed with 374 patients, randomized to subcutaneous and intracutaneous leg-wound closure with either triclosan-coated sutures (Vicryl Plus® and Monocryl Plus®, Ethicon, Somerville, NJ, USA) (n = 184) or identical sutures without triclosan (n = 190) from the same manufacturer. All patients were followed up after 30 days (clinical visit) and 60 days (telephone interview). Primary endpoint was SSI within 60 days after surgery according to the definition of Center for Disease Control. Predefined secondary endpoints included culture-proven and antibiotic-treated SSI. RESULTS The primary endpoint occurred in 23 patients (12.5%) with triclosan-coated sutures and in 38 patients (20.0%) in the group without triclosan (P = 0.0497, risk ratio 0.63, (95% confidence interval 0.39–1.00). Corresponding figures for culture-proven infections were 7.6 vs 12.1%, (P = 0.15), and for antibiotic-treated infections, 10.9 vs 18.4%, (P = 0.039). Staphylococcus aureus and coagulase-negative staphylococci were the most common pathogens in both groups. Insulin-treated diabetes and vein-harvesting time were associated with SSI after vein harvesting. CONCLUSIONS Leg-wound closure with triclosan-coated sutures in CABG patients reduces SSIs after open vein harvesting. (ClinicalTrials.gov number NCT01212315).

Bacterial recolonization of the skin and wound contamination during cardiac surgery: a randomized controlled trial of the use of plastic adhesive drape compared with bare skin

BACKGROUND Sternal wound infection after cardiac surgery is a serious complication. Various perioperative strategies, including plastic adhesive drapes, are used to reduce bacterial contamination of surgical wounds. AIM To compare plastic adhesive drape to bare skin regarding bacterial growth in wound and time to recolonization of the adjacent skin intraoperatively, in cardiac surgery patients. METHODS This single-blinded randomized controlled trial (May 2010 to May 2011) included 140 patients scheduled for cardiac surgery via median sternotomy. The patients were randomly allocated to the adhesive drape (chest covered with plastic adhesive drape) or bare skin group. Bacterial samples were taken preoperatively and intraoperatively every hour during surgery until skin closure. RESULTS Disinfection with 0.5% chlorhexidine solution in 70% alcohol decreased coagulase-negative staphylococci (CoNS), while the proportion colonized with Propionibacterium acnes was not significantly reduced and was still present in more than 50% of skin samples. P. acnes was significantly more common in men than in women. Progressive bacterial recolonization of the skin occurred within 2-3 h. At 120 min there were significantly more positive cultures in the adhesive drape group versus bare skin group for P. acnes (63% vs 44%; P = 0.034) and for CoNS (45% vs 24%; P = 0.013). The only statistically significant difference in bacterial growth in the surgical wound was higher proportion of CoNS at the end of surgery in the adhesive drape group (14.7% vs 4.4%; P = 0.044). CONCLUSION Plastic adhesive drape does not reduce bacterial recolonization. P. acnes colonized men more frequently, and was not decreased by disinfection with chlorhexidine solution in alcohol.

Antibiotic Concentrations in Serum and Wound Fluid after Local Gentamicin or Intravenous Dicloxacillin Prophylaxis in Cardiac Surgery

One important aim of antibiotic prophylaxis in cardiac surgery is preventing mediastinitis and thus it would appear to be relevant to study the antibiotic concentrations in pericardial/mediastinal fluid. Local administration of gentamicin in the wound before sternal closure is a novel way of antibiotic prophylaxis and could be effective against bacteria resistant to intravenous antibiotics. This study measured dicloxacillin concentrations in 101 patients in serum and wound fluid following intravenous administration of dicloxacillin. Similarly, concentrations of gentamicin in serum and wound fluid were determined in 30 patients after administration of 260 mg gentamicin in the wound at sternal closure. Median dicloxacillin concentrations in serum and wound fluid at sternal closure were 59.4 and 55.35 mg/l, respectively. Gentamicin levels in the wound were very high (median 304 mg/l), whereas serum concentrations were low (peak median 2.05 mg/l). Dicloxacillin, 1 g given intravenously, according to the clinical protocol, resulted in levels in serum and wound fluid at sternal closure likely to prevent Staphylococcus aureus infections. Locally administered gentamicin resulted in high local concentrations, potentially effective against agents normally considered resistant.

The 2011 outcome from the Swedish Health Care Registry on Heart Disease (SWEDEHEART).

Abstract Objectives. The Swedish Web-system for Enhancement and Development of Evidence-based care in Heart disease Evaluated According to Recommended Therapies (SWEDEHEART) collects data to support the improvement of care for heart disease. Design. SWEDEHEART collects on-line data from consecutive patients treated at any coronary care unit n = (74), followed for secondary prevention, undergoing any coronary angiography, percutaneous coronary intervention, percutaneous valve or cardiac surgery. The registry is governed by an independent steering committee, the software is developed by Uppsala Clinical Research Center and it is funded by The Swedish national health care provider independent of industry support. Approximately 80,000 patients per year enter the database which consists of more than 3 million patients. Results. Base-line, procedural, complications and discharge data consists of several hundred variables. The data quality is secured by monitoring. Outcomes are validated by linkage to other registries such as the National Cause of Death Register, the National Patient Registry, and the National Registry of Drug prescriptions. Thanks to the unique social security number provided to all citizens follow-up is complete. The 2011 outcomes with special emphasis on patients more than 80 years of age are presented. Conclusion. SWEDEHEART is a unique complete national registry for heart disease.

Cost effectiveness of local collagen-gentamicin as prophylaxis for sternal wound infections in different risk groups

Objectives. In a randomized trial addition of local collagen-gentamicin in the sternal wound reduced the rate of sternal wound infection (SWI) to about 50% compared to intravenous prophylaxis alone. The aim of the present study was to evaluate the economic rationale for its use in every-day clinical practice. This includes the question whether high-risk groups that may have particular benefit should be identified. Design. For each patient with SWI in the trial the costs attributable to the SWI were calculated. Risk factors for SWI were identified and any heterogeneity of the effect of the prophylaxis examined. Results. The mean cost of a SWI was about 14500 Euros. A cost effectiveness analysis showed that the prophylaxis was cost saving. The positive net balance was even higher in risk groups. Assignment to the control group, overweight, diabetes, younger age, mammarian artery use, left ventricular ejection fraction < 35% and longer operation time were independent risk factors for infection. Conclusion. The addition of local collagen-gentamicin to intravenous antibiotic prophylaxis was dominant, i.e. resulted in both lower costs and fewer wound infections.

Local collagen‐gentamicin for prevention of sternal wound infections: the LOGIP trial

In cardiac surgery, sternal wound infection (SWI) continues to be one of the most serious postoperative complications. Coagulase‐negative staphylococci (CoNS) have become the most common causative agents of SWI. However, many CoNS species are resistant to routine intravenous antibiotic prophylaxis. 2000 cardiac surgery patients were randomised to routine prophylaxis with intravenous isoxazolyl penicillin alone (control group) or to this prophylaxis combined with application of collagen‐gentamicin (260 mg gentamicin) sponges within the sternotomy before wound closure. The primary end‐point was any sternal wound infection within 2 months postoperatively. The incidence of any sternal wound infection was 4.3% in the treatment group and 9.0% in the control group (relative risk=0.47; 95% confidence interval 0.33 to 0.68; P<0.001). Local gentamicin reduced the incidence of SWI caused by all major clinically important microbiological agents, including CoNS. Routine use of the described prophylaxis in all adult cardiac surgery patients could be recommended.

Cost analysis of re-exploration for bleeding after coronary artery bypass graft surgery

BACKGROUND Re-exploration for bleeding after cardiac surgery is an indicator of substantial haemorrhage and is associated with increased hospital resource utilization. This study aimed to analyse the costs of re-exploration and estimate the costs of haemostatic prophylaxis. METHODS A total of 4232 patients underwent isolated, first-time, coronary artery bypass graft (CABG) surgery during 2005-8. Each patient re-explored for bleeding (n=127) was matched with two controls not requiring re-exploration (n=254). Cost analysis was based on resource utilization from completion of CABG until discharge. A mean cost per patient for re-exploration was calculated. Based on this, the net cost of prophylactic treatment with haemostatic drugs for preventing re-exploration was calculated. RESULTS Patients undergoing re-exploration had higher exposure to clopidogrel before operation, prolonged stays in the intensive care unit, and more blood transfusions than controls. The mean incremental cost for re-exploration was €6290 [95% confidence interval (CI) €3408-€9173] per patient, of which 48% [€3001 (95% CI €249-€2147)] was due to prolonged stay, 31% [€1928 (95% CI €1710-€2147)] to the cost of surgery/anaesthesia, 20% [€1261 (95% CI €1145-€1378)] to the increased number of blood transfusions, and <2% [€100 (95% CI €39-€161)] to the cost of haemostatic drugs. A cost model, at an estimated 50% efficacy for recombinant activated clotting factor VIIa and a 50% expected risk for re-exploration without prophylaxis, demonstrated that to be cost neutral, prophylaxis of four patients needed to result in one avoided re-exploration. CONCLUSIONS The resource utilization costs were substantially higher in patients requiring re-exploration for bleeding. From a strict cost-effectiveness perspective, clinical interventions to prevent haemorrhage might be underutilized.