Risk of embolism post retrograde catheterization
Risk of embolism post retrograde catheterization
Thu, 10 Apr 2003 22:30:00
Bonn, Germany - Patients with aortic valve stenosis who undergo retrograde catheterization of the aortic valve are at an increased risk of clinically apparent cerebral embolism and frequently have silent ischemic brain lesions, say authors of a recent study. Patients should be made aware of these risks, and the procedure should be performed only in patients with unclear echocardiographical findings when additional information is required for clinical management, they add.
The study is presented in the April 10, 2003 issue of The Lancet.
According to investigators, catheterization of the aortic valve to assess the severity of aortic valve stenosis poses a potential risk to patients undergoing the procedure, as the catheter crosses the stenosed valve and has been shown to dislodge calcium plaque, increasing the risk of embolism.
"I think, for the most part, we are very careful in selecting our patients for these riskier procedures," said lead investigator Dr Heyder Omran (University of Bonn, Germany) in an interview with heartwire. "But sometimes, maybe because the doctor urges it or the patient asks for it, these invasive procedures are done when noninvasive methods, such as a good echo, can avoid exposing the patient to certain risks."
Until recently, previous studies assessing the potential risks of catheterization have looked only at the incidence of clinically apparent cerebral embolism. These studies, said Omran, do not take into account clinically hidden brain damage, such as silent thromboembolism.
Modern MRI techniques, in particular diffusion-weighted MRI, are highly sensitive and specific for the detection of acute ischemic cerebral lesions, permitting "the detection of even very small, acute infarction at almost any anatomical location within the brain hemispheres, brain stem, and cerebellum," write Omran et al.
Between 1997 and 2001, investigators prospectively randomized 152 consecutive patients with aortic valve stenosis at a German university hospital to receive either cardiac catheterization with or without passage through the aortic valve. In total, 101 patients were randomized to receive retrograde catheterization with passage through the aortic valve and the remaining 51 patients were randomized to catheterization without passage through the aortic valve. Patients without aortic valve stenosis who underwent coronary angiography, including passage through the aortic valve for left heart catheterization, served as the control group.
All patients were assessed clinically and those with a history of previous embolism, as well as those with aortic plaque, were excluded from the study. Age, sex, history of embolism, occurrence of CAD, AF, and other cardiovascular risk factors did not differ between those undergoing catheterization for aortic stenosis (with and without passage through the aortic valve) compared with the control group. Compared with these patients, the controls more frequently had CAD and a history of embolism.
"We had to be careful as we didn't want to be fooled by other sources of emboli," said Omran. "We sought to get an even distribution of patients across the groups."
MRI was done one day before and within 48 hours after cardiac catheterization and assessed by radiologists blinded to patient status and trial procedure. Patients also underwent neurological assessment before the procedure and one day after catheterization.
The results of the diffusion-weighted MRI scan showed that after cardiac catheterization, 22 of the 101 patients (22%) who underwent the procedure with passage through the aortic valve showed acute cerebral diffusion abnormalities consistent with patterns of embolic lesions. The total number of cerebral lesions was 30, as four patients had more than one embolic lesion. The hemispheric branches of the middle cerebral artery (n=17) were most commonly affected. Three of 101 patients (3%) had an acute, clinically apparent neurological complication with abnormalities also recorded on their postprocedure MRI.
Of the 22 patients who showed MRI abnormalities after the procedure, 17 were followed up with conventional MRI at three months.
"All 17 patients developed a focal signal hyperattenuation in the region corresponding to the original index lesion, showing infarcted brain tissue," write Omran et al. "Neither the patients in group 2 [cardiac catheterization without passage through the aortic valve] nor the controls had acute diffusion abnormalities after the procedure."
Investigators conclude that cardiac catheterization has a potential risk of neurological complications and should only be used when echo findings are unclear or there is a discrepancy between clinical assessment and echo results.
Skill of the operator important
In an interview with heartwire, Dr Charles J Davidson (Northwestern University-Feinberg School of Medicine, Chicago, IL) said the conclusions of the German investigatorscardiac catheterization only in patients with unclear echo findingsare in line with current clinical practice guidelines.
However, he said, the high rates of complication in the German study contradict previously published data, as well as rates seen in clinical practice.
"The high complication rate brings the skill of the catheter operators into question," said Davidson. "As well, the method they used to cross the stenosed valve, advancing using the pigtail method, is more difficult than conventional methods."
The right coronary catheter with guidewire is the more traditional method of crossing the valve, said Davidson, and is not considered a risky or difficult procedure by skilled operators. While expert consultant cardiologists undertook the German cardiac catheterizations, Davidson noted the procedure was abandoned if the aortic valve could not be crossed in 30 minutes, an "excessive amount of time for operators accustomed to doing the procedure."
Davidson agreed that catheterization of the aortic valve need not be performed when echo findings are clear. However, he said relying only on echo findings is sometimes not an option.
"In managing patients, especially those who may need valve replacement, it is often necessary to confirm the echo findings," said Davidson. "The stenosed valve may be more or less severe than what is showing up on the echo. Before the surgery is done, we'd like to be able to see that."
Bonn, Germany - Patients with aortic valve stenosis who undergo retrograde catheterization of the aortic valve are at an increased risk of clinically apparent cerebral embolism and frequently have silent ischemic brain lesions, say authors of a recent study. Patients should be made aware of these risks, and the procedure should be performed only in patients with unclear echocardiographical findings when additional information is required for clinical management, they add.
The study is presented in the April 10, 2003 issue of The Lancet.
According to investigators, catheterization of the aortic valve to assess the severity of aortic valve stenosis poses a potential risk to patients undergoing the procedure, as the catheter crosses the stenosed valve and has been shown to dislodge calcium plaque, increasing the risk of embolism.
"I think, for the most part, we are very careful in selecting our patients for these riskier procedures," said lead investigator Dr Heyder Omran (University of Bonn, Germany) in an interview with heartwire. "But sometimes, maybe because the doctor urges it or the patient asks for it, these invasive procedures are done when noninvasive methods, such as a good echo, can avoid exposing the patient to certain risks."
Until recently, previous studies assessing the potential risks of catheterization have looked only at the incidence of clinically apparent cerebral embolism. These studies, said Omran, do not take into account clinically hidden brain damage, such as silent thromboembolism.
Modern MRI techniques, in particular diffusion-weighted MRI, are highly sensitive and specific for the detection of acute ischemic cerebral lesions, permitting "the detection of even very small, acute infarction at almost any anatomical location within the brain hemispheres, brain stem, and cerebellum," write Omran et al.
Between 1997 and 2001, investigators prospectively randomized 152 consecutive patients with aortic valve stenosis at a German university hospital to receive either cardiac catheterization with or without passage through the aortic valve. In total, 101 patients were randomized to receive retrograde catheterization with passage through the aortic valve and the remaining 51 patients were randomized to catheterization without passage through the aortic valve. Patients without aortic valve stenosis who underwent coronary angiography, including passage through the aortic valve for left heart catheterization, served as the control group.
All patients were assessed clinically and those with a history of previous embolism, as well as those with aortic plaque, were excluded from the study. Age, sex, history of embolism, occurrence of CAD, AF, and other cardiovascular risk factors did not differ between those undergoing catheterization for aortic stenosis (with and without passage through the aortic valve) compared with the control group. Compared with these patients, the controls more frequently had CAD and a history of embolism.
"We had to be careful as we didn't want to be fooled by other sources of emboli," said Omran. "We sought to get an even distribution of patients across the groups."
MRI was done one day before and within 48 hours after cardiac catheterization and assessed by radiologists blinded to patient status and trial procedure. Patients also underwent neurological assessment before the procedure and one day after catheterization.
The results of the diffusion-weighted MRI scan showed that after cardiac catheterization, 22 of the 101 patients (22%) who underwent the procedure with passage through the aortic valve showed acute cerebral diffusion abnormalities consistent with patterns of embolic lesions. The total number of cerebral lesions was 30, as four patients had more than one embolic lesion. The hemispheric branches of the middle cerebral artery (n=17) were most commonly affected. Three of 101 patients (3%) had an acute, clinically apparent neurological complication with abnormalities also recorded on their postprocedure MRI.
Of the 22 patients who showed MRI abnormalities after the procedure, 17 were followed up with conventional MRI at three months.
"All 17 patients developed a focal signal hyperattenuation in the region corresponding to the original index lesion, showing infarcted brain tissue," write Omran et al. "Neither the patients in group 2 [cardiac catheterization without passage through the aortic valve] nor the controls had acute diffusion abnormalities after the procedure."
Investigators conclude that cardiac catheterization has a potential risk of neurological complications and should only be used when echo findings are unclear or there is a discrepancy between clinical assessment and echo results.
Skill of the operator important
In an interview with heartwire, Dr Charles J Davidson (Northwestern University-Feinberg School of Medicine, Chicago, IL) said the conclusions of the German investigatorscardiac catheterization only in patients with unclear echo findingsare in line with current clinical practice guidelines.
However, he said, the high rates of complication in the German study contradict previously published data, as well as rates seen in clinical practice.
"The high complication rate brings the skill of the catheter operators into question," said Davidson. "As well, the method they used to cross the stenosed valve, advancing using the pigtail method, is more difficult than conventional methods."
The right coronary catheter with guidewire is the more traditional method of crossing the valve, said Davidson, and is not considered a risky or difficult procedure by skilled operators. While expert consultant cardiologists undertook the German cardiac catheterizations, Davidson noted the procedure was abandoned if the aortic valve could not be crossed in 30 minutes, an "excessive amount of time for operators accustomed to doing the procedure."
Davidson agreed that catheterization of the aortic valve need not be performed when echo findings are clear. However, he said relying only on echo findings is sometimes not an option.
"In managing patients, especially those who may need valve replacement, it is often necessary to confirm the echo findings," said Davidson. "The stenosed valve may be more or less severe than what is showing up on the echo. Before the surgery is done, we'd like to be able to see that."
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