The notion that age over 70 years puts patients undergoing CABG at increased risk of stroke has been challenged by a large study, which suggests burden of atherosclerosis play a more important role.
While patients aged 60-65 were 70% more likely to have a stroke within 30 days of surgery than those under 60 – and those aged 65-70 were 140% more likely – the increasing risk levelled off at age 70.
The database study of more than 25,000 Danish patients who underwent CABG between 1997 and 2007 found a previous stroke increased a patient’s risk of stroke within 30 days of surgery four-fold. Stroke risk was also raised by diabetes 1.3-fold and hypertension 1.4-fold. Statin use lowered the risk of stroke by 20%.
The results contrasted with those of earlier studies suggesting the risk of stroke increased exponentially with age over 60 years, the authors wrote in Stroke.
The difference between theirs and earlier studies was use of the EuroSCORE to select candidates for surgery, they said.
“This study shows that by applying EuroSCORE criteria in selecting suitable candidates for CABG, the risk of stroke among patients age >70 years has been reduced to a constant rate…”
“Our data suggest that the risk of stroke after CABG in patients age >70 years is not caused by age per se, but rather is a consequence of the burden of atherosclerosis.”
The findings “challenge the generally accepted notion that elderly patients…should be considered at increased risk of perioperative stroke, and as a result, perhaps be denied surgery,” two experts wrote in an accompanying editorial.
Interventional cardiologist Dr Phil Harris told Cardiology Update the research showed that “in the absence of the other vascular risk factors, age is not particularly important and that’s the clinical approach that needs to be taken”.
“It dissects out the risk factors that are contributing to the higher rates with age. Age alone shouldn’t be the determining factor.”
“But what doesn’t come out in the study is the lengths these days surgeons go to and the extent to which they modify their surgical technique to try to minimise the risk of stroke,” he added.
Stroke 2011; doi: strokeaha.111.620880
http://stroke.ahajournals.org/content/early/2011/10/27/STROKEAHA.111.620880.abstract