ArticlesSilent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study
Introduction
The severity of valvular aortic stenosis can be accurately assessed non-invasively by echocardiography in most patients.1 Non-invasive measurements of the mean pressure gradient over the aortic valve correlate closely with measurements obtained invasively.2 In patients with unclear transthoracic echocardiographical findings, multiplane transesophageal echocardiography allows the accurate measurement of the valvular aortic area,3, 4 if the valve is not too calcified. Nevertheless, cardiac catheterisation is often undertaken to establish aortic valvular area and pressure gradient invasively, especially in patients who are scheduled for aortic valve replacement.
The pressure gradient over the aortic valve can be assessed by two methods: either by simultaneous pressure measurements in the ascending aorta and in the left ventricle, or by non-simultaneous measurement of the pressures in the left ventricle and the ascending aorta. In the first method, puncture of the intra-atrial septum is necessary and a catheter is advanced in the left ventricle. However, this technique carries a substantial risk due to complications related to the puncture, and is therefore rarely undertaken. The second method requires retrograde passage of a catheter through the stenosed aortic valve. Then, the pressure is measured in the left ventricle. Afterwards, the catheter is ithdrawn and the pressure in the ascending aorta is obtained. This procedure avoids the puncture-related complications of the first technique.
However, crossing the stenosed aortic valve is associated with a potential risk of cerebral embolism, which has been related to the dislodgment of calcific valve particles of the stenosed valve; calcific embolism has been shown by computed tomography in a case of valvular aortic stenosis 2 days after cardiac catheterisation.5 A retrospective cohort study estimated the risk of clinically apparent cerebral embolism after the latter procedure as 1·7%.6 This and other investigations have only assessed the incidence of clinically apparent cerebral embolism related to this procedure. Clinically hidden brain damage-ie, silent thromboembolism—has not been taken into account.
Modern MRI techniques are highly sensitive and specific for the detection of acute ischaemic cerebral lesions.7, 8 Diffusion-weighted MRI provides image contrast that is dependent on the molecular motion of water, which is substantially altered by acute cerebral ischaemia.9 The addition of these methods to conventional MRI sequences permits the detection of even very small, acute infarction at almost any anatomical location within the brain hemispheres, brain stem, and cerebellum.7 This technique can serve as a useful surrogate endpoint for ischaemic stroke, and can be used to objectively and quantitatively monitor thromboembolism associated with cardiovascular catheter procedures and interventions.10, 11, 12, 13
The high sensitivity of diffusion-weighted imaging suggests that this technique could produce an improved estimate of cerebral ischaemic events associated with cardiovascular-catheter procedures.10 We therefore undertook a prospective, randomised study with diffusion-weighted MRI, to assess the incidence of clinically apparent and silent cerebral embolism after retrograde catheterisation of the aortic valve in patients with valvular aortic stenosis.
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Study population
From April, 1997, to December, 2001, all patients aged more than 18 years with known or suspected valvular aortic stenosis who underwent catheterisation were included in our investigation. Exclusion criteria were contraindication to MRI or transoesophageal echocardiography, or inability to give written informed consent. Additionally, we excluded patients with unclear echocardiographic findings—ie, low pressure gradient over the aortic valve, established by Doppler echocardiography, and
Results
152 patients were included in the study and randomized into the two study groups: 101 patients undergoing retrograde catheterisation of the aortic valve formed group 1, and 51 patients without passage through the valve formed group 2 (figure 1). 32 patients without valvular aortic stenosis who underwent coronary angiography to exclude coronary artery disease were controls. Table 1 shows patients' characteristics. Age, sex, history of embolism, occurrence of coronary artery disease, other
Discussion
We assessed the frequency of clinically silent and apparent cerebral embolism, with modern magnetic resonance imaging techniques, in patients with degenerative aortic valve stenosis undergoing cardiac catheterisation with transvalvular passage. Our main findings are that retrograde catheterisation of valvular aortic stenosis is associated with a high rate of clinically silent cerebral embolism (22%) and can lead to clinical symptoms of neurological deficits in 3% of patients.
These data for rate
References (19)
- et al.
Comparison of Doppler-derived pressure gradient to that determined at cardiac catheterization in adults with aortic valve stenosis: implications for management
Am J Cardiol
(1986) - et al.
Simultaneous determination of aortic valve area by the Gorlin formula and by transesophageal echocardiography under different transvalvular flow conditions: evidence that anatomic aortic valve area does not change with variations in flow in aortic stenosis
J Am Coll Cardiol
(1997) - et al.
Silent embolism in diagnostic cerebral angiography and neurointerventional procedures: a prospective study
Lancet
(1999) - et al.
Left atrial chamber and appendage function after internal atrial defibrillation: a prospective and serial transesophageal echocardiographic study
J Am Coll Cardiol
(1997) - et al.
Echocardiographic parameters for predicting maintenance of sinus rhythm after internal atrial defibrillation
Am J Cardiol
(1998) - et al.
Hydraulic formula for calculation of area of stenotic mitral valve, other cardiac values and central circulatory shunts
Am Heart J
(1951) Doppler echocardiographic evaluation of aortic and mitral stenoses
Echocardiography
(1999)- et al.
Planimetry of orifice area in aortic stenosis using multiplane transesophageal echocardiography
J Am Coll Cardiol
(1993) - et al.
Calcific cerebral emboli and aortic stenosis: detection of computed tomography
Stroke
(1986)
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