The severity of valvular aortic stenosis (a narrowing of the valve between the left ventricle of the heart and the aorta) can be accurately assessed non-invasively by echocardiography. However, retrograde catheterisation of the aortic valve is often undertaken to assess the degree of stenosis, especially for patients awaiting valve replacement; this procedure has a potential risk of neurological complications, with an unknown incidence of asymptomatic blood clots (known as clinically silent embolism).
Heyder Omran and Torsten Sommer from the University of Bonn, Germany, and colleagues prospectively randomised 152 patients with valvular aortic stenosis to receive either cardiac catheterisation with (101 patients) or without (51 patients) passage through the aortic valve. All participants underwent cranial MRI and had neurological assessment within two days before and after the procedure to assess cerebral blood clots. 32 people without valvular aortic stenosis who underwent coronary angiography were the control group for the study.
Around a fifth (22%) of patients who underwent retrograde catheterisation of the aortic valve had indications of cerebral blood clots from MRI scans; three of these had impaired neurological function. By contrast, none of the patients who did not have catheterisation through the valve, or any of the controls, had evidence of cerebral blood clots.
Heyder Omran and Torsten Sommer comment: "We have shown that patients undergoing retrograde catheterisation of a stenotic aortic valve are at a substantial risk of clinical neurological complications. Furthermore, we noted a far greater frequency of clinically silent cerebral embolic lesions than clinical embolism in these patients. Thus, the substantial risk of structural ischaemic brain damage related to the passage of a stenotic aortic valve has been underestimated in the past. We should inform patients about these procedure-related risks, and retrograde catheterisation of the stenotic aortic valve should only be undertaken when patients' echocardiographic findings are unclear and additional information is essential for clinical management."
Contact: Dr Heyder Omran, University of Bonn, Sigmund-Freud -Strasse 25, D-53105 Bonn, Germany;
T) 49-228-287-6076;
F) 49-228-287-4983;
E) omran@uni-bonn.de
Journal
The Lancet