Flexible stent can reduce complications in coronary artery surgery
The standard treatment for coronary artery stenosis is balloon angioplasty (PCI), where a drug-eluting stent is placed in the vessel to open it up for blood to pass through. A large national randomised trial, led by Uppsala Clinical research Center (UCR), shows that a new, more compliant coronary stent minimises the risk of reoccurrence of angina or a new heart attack in the same vessel.
– The results are very positive for the patients concerned and can hopefully lead to a better standard of care for people with coronary artery stenosis, including young people. The new flexible stent, which has been evaluated, reduces the risk of suffering from angina again or having a new heart attack in the same vessel, says Maria Eriksson Svensson, Professor of Renal Medicine and Director of the Uppsala Clinical Research Centre (UCR) at Uppsala University Hospital.
UCR has led the Infinity-Swedeheart study and Uppsala University Hospital is one of the 20 Swedish hospitals where most patients were recruited. A total of 2,400 patients who had a heart attack or angina were included. Participants were randomised to receive either the new DynamX Bioadaptor flexible stent or the conventional Resolute Onyx stent. Patients were then followed up in the Swedish quality register Swedeheart.
The standard treatment for heart disease caused by narrowing of the coronary arteries is balloon angioplasty, also known as PCI (Percutaneous Coronary Intervention). This involves inserting a drug-eluting stent, a small metal mesh tube, into the blood vessel. For many patients, this method works well, but in about two to three per cent of patients, the stents cause new narrowing or angina each year.
– The reduced risk of complications with this new, more flexible type of stent is related to its more physiological function. After six months, it has partially dissolved and opened up like a kind of zip. My assessment is that this could become a standard treatment for coronary artery disease in the future, explains Stefan James, Professor of Cardiology and Scientific Director at UCR, who also chairs the study's steering committee.
The researchers also note that the new stent performs as well as standard stents at the time of implantation without any unexpected complications. According to James, the most interesting thing is what happens after six months, when the new stent has acquired its flexible/elastic shape.
– We found that complications were significantly lower among those stented with the new technique compared to the control group. The proportion who suffered cardiovascular death, heart attack or had to undergo reoperation in the stented vessel was 0.6% compared with 1.8% in each group six months to a year after the procedure. This could lead to more young patients being considered for such treatment. And the difference seems to be getting bigger over time. We will now continue to follow the patients for 15 years to see how big the differences become in the future, he concludes.