None listed
Conditions
Brief summary
More than 50% of patients requiring surgery for enlargement (aneurysm) of the aorta or narrowing of the carotid or limb arteries have coexistent coronary disease. Indeed, cardiac problems account for the majority of operative complications in patients undergoing vascular surgery. Individuals who have a low cardiac risk from these operations can be identified by clinical evaluation, especially if a stress test is negative. However, if a test is positive, the risk of having a cardiac complication is <20-30%. The optimal response to this finding is still unclear. In this situation, patients are often referred for bypass surgery or coronary balloon angioplasty in order to treat their coronary disease. However, this approach may be inappropriately aggressive, as 70% or more of the patients will undergo their vascular surgery uneventfully. Moreover, patients with vascular disease are often elderly, and have other diseases that make heart operations more difficult and risky than usual. An alternative is the use of medical therapy to protect the heart, but the efficacy of this approach in reducing peri-operative complications is debated. This multicentre study, based at hospitals in the mainland capital cities of Australia, will examine patients with a positive stress test, and then use the results of the test to identify high and intermediate risk levels. Patients will be excluded from the study if the stress test is strongly positive, and a heart operation is definitely in the patient's best interests. In other situations, where the best approach to therapy is unproven, patients will be randomized to a regimen involving intensive medical therapy to protect the heart, or coronary angiography with the intent of myocardial revascularization if possible. Patients will be followed up for events of the time of surgery, and outcome (including quality of life) will be assessed six months after the operation.
Interventions
Patients having major non cardiac surgery are assessed prior to the procedure. If no exclusion criteria are met (see below), they are assessed using a clinical score with one point given for each risk factor. Those patients with 1-2 risk factors are classified as intermediate risk and those with >2 are classified as high risk.
Intermediate risk patients are randomized to bisoprolol only (ie. no further risk evaluation) or usual care (dobutamine echo and standard responses to a positive or negat
Patients having major non cardiac surgery are assessed prior to the procedure. If no exclusion criteria are met (see below), they are assessed using a clinical score with one point given for each risk factor. Those patients with 1-2 risk factors are classified as intermediate risk and those with >2 are classified as high risk. Intermediate risk patients are randomized to bisoprolol only (ie. no further risk evaluation) or usual care (dobutamine echo and standard responses to a positive or negative test). Standard responses to a positive test usually involve use of a standard beta blocker without careful titration to heart rate. A standard response to a negative test involves no specific therapy. Oral bisoprolol is started at 5mg a day, reassessed at one week and if pulse rate remains >60 and other vital signs are stable the dose is increased to 10mg. The bisoprolol is continued for a month following surgery. The patient is reassessed and referred to their general practitioner with a recommendation to continue with a more common beta-blocker. All high risk patients undergo a dobutamine stress echo. If the results are negative they have usual care and follow up but are not randomized for further study. If the results are positive they are randomized to a triad of oral medications - bisoprolol (to titrate heart rate <60 as above), aspirin (100 mg/d) and simvastatin (40 mg/d) or usual care. Usual care comprises use of a standard beta blocker (as above), with selective use of coronary angiography and coronary intervention, usually guided by the patient’s symptom status). Trial drugs are continued for one month after surgery. All patients are given a Quality of Life Survey on admission to the trial and at six months. Electrocardiograms and Troponin levels are done daily for 3 days post operatively and repeated on discharge or Day 7. All patients are reviewed at one and six months, electrocardiograms are repeated.
Sponsors
Professor T Marwick
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Prevention
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
Major non cardiac surgery in subjects with one or more of the following risk factors; age over 70years, previous myocardial infarct, diabetes mellitus, angina and chronic heart failure.
Exclusion criteria
Asthma, bradycardia, laparoscopic procedures, and aortic stents.
Outcome results
None listed