The practicalities of establishing a porcine isolated heart model.

BACKGROUND: The isolated heart apparatus is over 100 years old, but remains a useful research tool today. While designs of many large animal systems have been described in the literature, trouble-shooting and refining such a model to yield a stable, workable system has not been previously described. This paper outlines the issues, in tabular form, that our group encountered in developing our own porcine isolated heart rig with the aim of assisting other workers in the field planning similar work. The paper also highlights some of the modern applications of the isolated heart apparatus. Methods Landrace pigs (50-80 kg) were used in a pilot project to develop the model. The model was then used in a study examining the effects of various cardioplegic solutions on function after reanimation of porcine hearts. During the two projects, non-protocol issues were documented as well as their solutions. These were aggregated in this paper. RESULTS: Issues faced by the group without explicit literature solutions included pig size selection, animal acclimatisation, porcine transoesophageal echocardiography, cannulation and phlebotomy for cross-clamping, cardioplegia delivery, heart suspension and rig tuning. CONCLUSION: Prior recognition of issues and possible solutions faced by workers establishing a porcine isolated heart system will speed progress towards a useable system for research. The isolated heart apparatus remains applicable in transplant, ischaemia reperfusion, heart failure and organ preservation research.

Impact of the introduction of drug eluting stents on clinical outcomes in patients undergoing percutaneous and surgical coronary artery revascularisation procedures in Western Australia.

BACKGROUND: Increasing rates of percutaneous coronary intervention (PCI) and decreasing rates of coronary artery bypass graft (CABG) surgery followed the introduction of drug eluting stents in Western Australia in 2002. We assessed the impact of these changes on one-year outcomes for the total population of patients undergoing coronary artery revascularisation procedures (CARP) in Western Australia between 2000-2004. METHODS: Clinical and linked administrative data (inpatient admissions and death) were merged for all patients who had their first CARP with stent or CABG in Western Australia between 2000-2004. The clinical data were collected from all hospitals in Western Australia where CARP procedures are performed. We calculated the unadjusted (Kaplan-Meier) and adjusted (Cox) risks for one-year death (all-cause), death (all-cause) or admission for myocardial infarction (MI), target vessel revascularisation (TVR) and the composite outcome of death/MI/TVR (major adverse cardiac events, MACE). RESULTS: Over the study period, there were 14,118 index CARPs. The use of drug eluting stents increased from 0% to 95.8% of PCI procedures, and PCI procedures increased from 61.1% to 74.4% of all CARPS. There were no temporal changes in adjusted one-year mortality or death/MI. Overall, adjusted one-year MACE fell from 11.3% in 2000 to 8.5% in 2004 (p<0.0001) due to a significant reduction in TVR in the PCI group. CONCLUSION: The introduction of drug eluting stents and resulting changes in coronary revascularisation strategies were not associated with changes in the one-year risk of major clinical endpoints (death or death/MI), but were associated with a significant reduction in the risk of MACE, driven entirely by a reduction in TVR after PCI. This real world study supports the effectiveness of drug eluting stents in reducing repeat procedures in the total CARP population without increasing the risk of death or MI.

Non-lethal? Penetrating chest injury due to beanbag bullet.

We report a case of serious lung injury from beanbag bullet. A 46-year-old gentleman, shot with beanbag bullets was brought to the emergency department. Upon arrival he was in obvious respiratory distress and complained of severe pain in the right chest. A 3.0×3.5 cm entry wound on the right parasternal area was identified. Chest x-ray revealed a right haemopneumothorax, parenchymal changes at the right lung base and a radiopaque foreign body. A right-sided intercostal chest tube was inserted, draining air and 750 ml of blood. After stabilisation patient underwent a right thoracotomy. A beanbag bullet was found in the oblique fissure of the right lung, with extensive haematoma of the middle lobe. The bullet and skin fragments overlying the lung and along the bullet track were extracted. The pleural cavity was washed with normal saline and haemostasis was confirmed. The patient had an uneventful postoperative recovery.

Reduction of surgical site infection using a microbial sealant: a randomized trial.

OBJECTIVE: Surgical site infection is a major cause of mortality and morbidity. We have explored the use of a microbial sealant applied before the surgical incision to reduce surgical site infection. METHODS: We conducted a prospective, randomized, controlled clinical trial to determine the efficacy of a cyanoacrylate sealant in patients undergoing coronary artery bypass grafting. Both left and right long saphenous veins were harvested in individual patients below the knee if 3 or more lengths of vein were required. The sealant (Kimberly-Clark InteguSeal, Roswell, Ga) was applied to 1 leg chosen randomly, and the other leg was prepared in a conventional fashion. Microbiological swabs from the leg wounds were taken at 5 days, and wounds were assessed according to the Southampton score at 30 days by 2 blinded observers. RESULTS: The baseline characteristics of the treated and untreated legs were similar because the procedure was conducted on each individual patient. The study was terminated at 47 patients after review. Patients in whom the sealant was used had 1 (2.1%) wound infection, and there were 12 (25.5%) wound infections in the conventionally prepared leg (P = .001). There were 13 positive cultures from the treated leg and 22 positive cultures from the untreated site. CONCLUSIONS: The microbial skin sealant applied immediately before the incision significantly reduced the rate of surgical site infection. There was no sensitivity or adverse reaction after application. The treatment was easily integrated with existing routine preoperative procedures. Microbial sealant may thus be a useful addition to a multimodal approach to minimize surgical site infection.

Unusual positron emission tomography findings in pulmonary amyloidosis: a case report.

Positron emission tomography (PET) has come to play an increasingly important role in the evaluation of pulmonary lesions, which are suspicious of malignancy. As is true for other techniques, PET gives false positive and negative results. We report a case of pulmonary amyloidosis with multiple pulmonary nodules showing different uptake of 18 F-fluorodeoxyglucose (FDG) on PET. There are limitations of specificity of FDG-PET in characterising pulmonary nodules and it is important to confirm a suspected malignancy with histology before potentially curative treatment is undertaken.

Asymptomatic long-term survivors of coronary artery bypass surgery enjoy a quality of life equal to the general population.

BACKGROUND: Health-related quality of life (HRQOL) among long-term survivors of coronary artery bypass surgery is an important outcome that has been little studied at the population level. METHODS: A postal survey was conducted in 1999 to 2000 in patients 6 to 20 years after coronary artery bypass graft (CABG) surgery in Western Australia. A random stratified sample of 2500 was drawn from 8910 patients who had their first CABG surgery in 1980 to 1993. Health-related quality of life was measured with Short Form 36 and EuroQol visual analogue scale. RESULTS: Response was 82% (n = 2061). Health-related quality of life declined with age and was similar for men and women, although scores for women were worse for physical functioning. Compared with Australian population norms, the age- and sex-standardized scores of survivors of CABG were generally worse, mainly in the physical domain. Reported angina at the time of follow-up (33%), symptoms of heart failure equivalent to New York Heart Association (NYHA) classes II to IV (34%), and comorbidities such as diabetes and hypertension were associated with poorer HRQOL. For both men and women without angina or heart failure at follow-up, HRQOL was no different from that of the general population. CONCLUSION: Overall, the quality of life among long-term survivors of CABG is worse than that of the general population, the difference being mainly attributable to recurrent symptoms and comorbidities. Quality of life for those without angina or heart failure at follow-up was equivalent to the population norms, providing an incentive to maximize efforts to abolish angina and ameliorate heart failure symptoms.

Return to work after coronary artery bypass surgery in a population of long-term survivors.

BACKGROUND: Return to paid employment may be facilitated by coronary artery bypass graft (CABG) surgery. We assessed work status in a population-based study of long-term outcomes of CABG. AIM: To determine the association between returning to work after CABG and clinical and socio-demographic factors. METHODS: A postal survey of 2,500 randomly selected patients 6-20 years post-CABG. The outcomes assessed were work status in the year before and after CABG and health-related quality of life (HRQOL) measured with SF-36. RESULTS: Response was 82% (n = 2,061). Employment fell from 56% in the year prior to CABG to 42% in the year after. Workers in 'blue-collar' occupations were more likely to reduce their work status than those in 'white collar' occupations (46% versus 29%, p < 0.001). Independent predictors of reducing employment were increasing age (9% per year, 99% CI: 1.06-1.11, p < 0.001), 'blue-collar' versus 'white collar' occupation (OR: 2.1, 99% CI: 1.4-3.1) and female sex (OR: 2.1, 99% CI: 1.1-3.6). HRQOL among participants under 60 years of age at follow-up was better for those who returned to work after CABG surgery. CONCLUSION: CABG surgery is followed by a net loss to paid employment of working age patients which increases with age, and is more likely for those in blue-collar occupations and women.

Preventing recurrent events long term after coronary artery bypass graft: suboptimal use of medications in a population study.

BACKGROUND: There are few population-based data on long-term management of patients after coronary artery bypass graft (CABG), despite the high risk for future major vascular events among this group. We assessed the prevalence and correlates of pharmacotherapy for prevention of new cardiac events in a large population-based series. METHODS: A postal survey was conducted of 2500 randomly selected survivors from a state population of patients 6 to 20 years after first CABG. RESULTS: Response was 82% (n = 2061). Use of antiplatelet agents (80%) and statins (64%) declined as age increased. Other independent predictors of antiplatelet use included statin use (odds ratio [OR] 1.6, 95% CI 1.26-2.05) and recurrent angina (OR 1.6, CI 1.17-2.06). Current smokers were less likely to use aspirin (OR 0.59, CI 0.4-0.89). Statin use was associated with reported high cholesterol (OR 24.4, CI 8.4-32.4), management by a cardiologist (OR 2.3, CI 1.8-3.0), and the use of calcium channel-blockers. Patients reporting hypertension or heart failure, in addition to high cholesterol, were less likely to use statins. Angiotensin-converting enzyme inhibitors were the most commonly prescribed agents for management of hypertension (59%) and were more frequently used among patients with diabetes and those with symptoms of heart failure. Overall 42% of patients were on angiotensin-converting enzyme inhibitors and 36% on beta-blockers. CONCLUSIONS: Gaps exist in the use of recommended medications after CABG. Lower anti-platelet and statin use was associated with older age, freedom from angina, comorbid heart failure or hypertension, and not regularly visiting a cardiologist. Patients who continue to smoke might be less likely to adhere to prescribed medications.