Elsevier

The Lancet

Volume 361, Issue 9365, 12 April 2003, Pages 1241-1246
The Lancet

Articles
Silent and apparent cerebral embolism after retrograde catheterisation of the aortic valve in valvular stenosis: a prospective, randomised study

https://doi.org/10.1016/S0140-6736(03)12978-9Get rights and content

Summary

Background

In most patients, severity of valvular aortic stenosis can be accurately assessed non-invasively by echocardiography. However, retrograde catheterisation of the aortic valve is often undertaken. This procedure has a potential risk of neurological complications, with an unknown incidence of clinically silent embolism. We aimed to establish the frequency of clinically apparent and silent cerebral embolism after this procedure.

Methods

We prospectively randomised 152 consecutive patients with valvular aortic stenosis at a German university hospital to receive either cardiac catheterisation with (n=101) or without (n=51) passage through the aortic valve. Patients underwent cranial MRI and neurological assessment within 48 h before and after the procedure to assess cerebral embolism. Controls were 32 patients without valvular aortic stenosis who underwent coronary angiography and laevocardiography.

Findings

22 of 101 patients (22%) who underwent retrograde catheterisation of the aortic valve had focal diffusion-imaging abnormalities in a pattern consistent with acute cerebral embolic events after the procedure; three of these patients (3%) had clinically apparent neurological deficits. By contrast, none of the patients without passage of the valve, or any of the controls, had evidence of cerebral embolism as assessed by MRI.

Interpretation

Patients with valvular aortic stenosis who undergo retrograde catheterisation of the aortic valve have a substantial risk of clinically apparent cerebral embolism, and frequently have silent ischaemic brain lesions. Patients should be informed about these risks, and this procedure should be used only in patients with unclear echocardiographical findings when additional information is necessary for clinical management.

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.

Section snippets

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)

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