Source :Karolinska Institutet
Infections of implanted heart valves are common in patients who have a biological valve prosthesis compared with those who received a mechanical. According to a study from Karolinska Institutet published July 17, 2017, in the journal Circulation .
Every year about 1500 people in Sweden surgical replacement of the aortic valve. Today about 75 percent may be a biological valve (pig or calf) and a mechanical rest. A complication with high mortality is that the new valve is infected by bacteria, so-called protesendokardit. Until now, there have been numbers if infection rates differ between the two different valve types. It was also unknown how common it is to suffer from infection of an artificial heart valve. The study from Karolinska Institutet included more than 26,500 patients who received a heart valve prosthesis between 1995 and 2012. Of these, 940 patients were affected by protesendokardit.
The risk of infection in the artificial heart valve was about 50 percent higher with a biological valve prosthesis compared with a mechanical valve prosthesis. The follow-up was the longest 18 years. We did not expect the big difference. Our results are important because they contribute to increased knowledge of complications after surgical aortic valve replacement, says Natalie Glaser, a doctor and PhD student at the Department of Molecular Medicine and Surgery , Karolinska Institutet.
In the current European guidelines for cardiology says that there is no difference in the incidence of infection between the two types of implants. Natalie Glaser believes that it may be because previous studies have been small and not able to show any difference. Moreover, they are done on patients who underwent surgery for several decades ago.
The new study has also provided updated figures on how common complication is; overall hit about 0.5 percent of the patients operated by protesendokardit annually. Furthermore, the results also show that the mortality rate was as high as 16 percent within a month of actual infection and 50 percent five years after diagnosis.
– Today, the choice of prosthetic valve widely by age. Biological valves are used mostly in elderly patients on medical grounds, partly because the biological valves do not require lifelong treatment with blood-thinning medications. In the current study, subjects given biological valves on average 13 years older than those who received mechanical but we have compensated for when we compared the results, says Ulrik Sartipy , heart surgeon at the Karolinska University Hospital and associate professor in the Department of Molecular Medicine and Surgery, Karolinska Institute, and responsible for the study.
The study is among others funded by the Heart and Lung Foundation, Mats Klebergs Foundation, the Magnus Bergvalls Foundation. Martin Holzmann has reported that he has received consulting fees from Actelion and Pfizer.
Source :Karolinska Institutet