Revista Societatii de Medicina Interna
Articolul face parte din revista :
Nr.1 din luna martie 2011
Autor S. Sankar
Titlu articolA NON-CORONARY USE OF THE PRESSURE WIRE: ACCURATE ASSESSMENT OF SUSPECTED PROSTHETIC VALVE DYSFUNCTION
Cuvinte cheiesenzorii de presiune plasați pe un fir de ghidare, leziuni coronariene, valve aortice prostetice, valvă monodisc
Articol
S. Sankar MD, Specialist Registrar in Cardiology,
A. Ionescu MD, FRCP, FESC, Consultant Cardiologist
Address for correspondence:
Dr A Ionescu
Consultant Cardiologist
Morriston Cardiac Centre
Swansea SA6 6NL
Wales, UK
E-mail: Adrian.Ionescu@wales.nhs.uk
Phone: (00) 44-(0) 1792-70-3195
Introduction
Pressure gradients across normally functioning prosthetic valves can be unexpectedly high by Doppler echocardiography, because of a hemodynamic phenomenon called pressure recovery(1). In patients with symptoms attributable to prosthetic valve obstruction it becomes essential to distinguish between valve dysfunction (which may require surgery) and pressure recovery (a ‘normal’ finding) as the cause of a high gradient, but invasive hemodynamic assessment in the catheter laboratory is not routinely performed because of the risks involved. Cardiac catheters should not be used to ‘cross’ prosthetic valves, as they may damage or ‘jam’ the occluder(2).
The pressure wire is an angioplasty guide wire with a pressure sensor mounted 3 cm proximal to the tip, and has been extensively validated in the coronaries, where it is used increasingly to determine which stenoses are hemodynamically significant. However, because of its dimensions and steerability it is also able to cross prosthetic valves without damaging them and its use has been reported before for measuring pressure gradients in bi-leaflet prosthetic valves in the aortic position(3,4). We are now reporting the first case where a single tilting-disc valve was crossed with a pressure wire in a patient with symptoms and a high gradient by Doppler.
Case presentation
A 71-year-old lady had aortic valve replacement 17 years previously, with a single tilting-disc valve (Medtronic Hall) for rheumatic aortic stenosis. Over the previous 5 years she had become increasingly short of breath. Two years previously she had coronary angiography in a different institution, where an ostial right coronary artery stenosis was diagnosed and she was listed for angioplasty, which she declined.
Transthoracic echocardiography demonstrated a Medtronic Hall valve with normal movement of the occluder, but with an elevated peak and mean transvalvular gradient (70 and 38 mm Hg respectively). We did not have a baseline recording for comparison.
Over the subsequent 2 years she became increasingly short of breath, while the echo findings remained stable. We decided to perform invasive hemodynamic assessment using a pressure wire (Radiwire, St Jude) to cross the valve and elucidate the gradient, and also to measure fractional flow reserve (FFR) across the right coronary ostial stenosis.
The patient was morbidly obese (BMI 32 kg/m2) but had refused catheterisation from the radial approach because of an unpleasant experience in another institution. We performed a right-sided femoral arterial puncture using standard techniques, gave 5000 units of unfractionated heparin via the arterial sheath, and advanced a 6F AL1 guide catheter to the ascending aorta under fluoroscopic guidance. The Radiwire was equalised and then was easily advanced across the prosthetic valve in the RAO projection (Figure 1).
We obtained simultaneous pressure readings from the LV and from the ascending aorta
These demonstrated much lower values than those recorded by echocardiography (peak gradient 27 mm Hg, mean 15 mm Hg), indicating that the findings were due to pressure recovery rather than to prosthetic valve malfunction.
We then used the same Radiwire to measure FFR across the ostial lesion (Figure 3) of the right coronary artery. We used intracoronary boluses of adenosine and demonstrated that the FFR was 0.89, well above the threshold for intervention.
We used intracoronary boluses of adenosine and demonstrated that the FFR was 0.89, well above the threshold for intervention.
Discussion
Before the widespread availability of Doppler echocardiography there were 3 ways to record a pressure trace in the left ventricle (LV) in patients with a prosthetic aortic valve: cross it with a catheter, perform a trans-septal puncture and measure the left ventricular LV pressure passing a catheter across the atrial septum, into the left atrium and then across the mitral valve, or record the intraventricular pressure through a trans-apical direct puncture of the LV(5), while a catheter in the aorta measured aortic pressure. All these methods are invasive, have a risk of fatal or severe complications and were performed infrequently.
After the first decade of use, it became clear that Doppler gradients across prosthetic valves - although easy to obtain, and reproducible in expert hands – have limitations(1, 6). A common and difficult conundrum arises when a patient with a prosthetic aortic valve replacement (AVR) presents with symptoms and the Doppler interrogation of the valve discloses a high pressure gradient. The difficulty is that normally functioning valves, mainly (but not exclusively) bi-leaflet and in small sizes, can display pressure recovery. This phenomenon leads to the measurement of a high velocity across the prosthetic valve by Doppler (which is translated into a high pressure drop by the Bernoulli equation), but this is not associated with abnormal turbulence or increased LV stroke work, so that the pressure ‘recovers’ a few centimetres above the valve.
It is difficult to justify sending such a patient for reoperation solely on the basis of the Doppler data, and the stakes are higher when the patient has comorbidities that would increase further the risk of reoperation. In such patients it is justifiable to pursue an invasive approach to record hemodynamic data which, together with imaging of the prosthetic valve, allow correct diagnosis and appropriate treatment.
The pressure wire has been used before to cross bi-leaflet AVRs(3, 4), but this is – we think – the first report of a single tilting disc prosthetic valve being crossed with a Radiwire. The Radiwire is widely available and accepted in catheter laboratories around the world for the assessment of coronary artery lesions, and it is important to increase awareness of other potential areas where it can provide unique and essential clinical information.
Acknowledgments
The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology
References
1. Baumgartner H, Khan S, DeRobertis M, Czer L, Maurer G. Discrepancies between Doppler and catheter gradients in aortic prosthetic valves in vitro. A manifestation of localized gradients and pressure recovery. Circulation. 1990; 82:1467-75.
2. Rigaud, M, Dubourg O, Luwaert R, Rocha P, Hamoir V, Bardet J, Bourdarias JP. Retrograde catheterization of left ventricle through mechanical aortic prostheses Eur Heart J 1987; 8, 689-696.
3. Doorey AJ, Gakhal M, Pasquale MJ,Utilization of a Pressure Sensor Guidewire to Measure Bileaflet Mechanical Valve Gradients: Hemodynamic and Echocardiographic Sequelae. Catheter Cardiovasc Intervent 2006; 67:535–540.
4. Parham W,Shafei AE, Rajjoub H, Ziaee A, Kern MJ. Retrograde Left Ventricular Hemodynamic Assessment Across Bileaflet Prosthetic Aortic Valves: The Use of a High-Fidelity Pressure Sensor Angioplasty Guidewire Catheter Cardiovasc Intervent 2003; 59:509–513.
5. Walters DL, Sanchez PL, Rodriguez-Alemparte M, Colon-Hernandez PJ, Hourigan LA, Palacios IF. Transthoracic Left Ventricular Puncture for the Assessment of Patients With Aortic and Mitral Valve Prostheses: The Massachusetts General Hospital Experience, 1989–2000. Cathet Cardiovasc Intervent 2003;58:539–544.
6. Aljassim O, Svensson G, Houltz E, Bech-Hanssen O.Doppler-catheter discrepancies in patients with bileaflet mechanical prostheses or bioprostheses in the aortic valve position. Am J Cardiol. 2008; 102:1383-9.
7. Shewan LG and Coats AJ. Ethics in the authorship and publishing of scientific articles Int J Cardiol 2010;144:1-2
Nr.1 din luna martie 2011
S. Sankar MD, Specialist Registrar in Cardiology,
A. Ionescu MD, FRCP, FESC, Consultant Cardiologist
Address for correspondence:
Dr A Ionescu
Consultant Cardiologist
Morriston Cardiac Centre
Swansea SA6 6NL
Wales, UK
E-mail: Adrian.Ionescu@wales.nhs.uk
Phone: (00) 44-(0) 1792-70-3195
Introduction
Pressure gradients across normally functioning prosthetic valves can be unexpectedly high by Doppler echocardiography, because of a hemodynamic phenomenon called pressure recovery(1). In patients with symptoms attributable to prosthetic valve obstruction it becomes essential to distinguish between valve dysfunction (which may require surgery) and pressure recovery (a ‘normal’ finding) as the cause of a high gradient, but invasive hemodynamic assessment in the catheter laboratory is not routinely performed because of the risks involved. Cardiac catheters should not be used to ‘cross’ prosthetic valves, as they may damage or ‘jam’ the occluder(2).
The pressure wire is an angioplasty guide wire with a pressure sensor mounted 3 cm proximal to the tip, and has been extensively validated in the coronaries, where it is used increasingly to determine which stenoses are hemodynamically significant. However, because of its dimensions and steerability it is also able to cross prosthetic valves without damaging them and its use has been reported before for measuring pressure gradients in bi-leaflet prosthetic valves in the aortic position(3,4). We are now reporting the first case where a single tilting-disc valve was crossed with a pressure wire in a patient with symptoms and a high gradient by Doppler.
Case presentation
A 71-year-old lady had aortic valve replacement 17 years previously, with a single tilting-disc valve (Medtronic Hall) for rheumatic aortic stenosis. Over the previous 5 years she had become increasingly short of breath. Two years previously she had coronary angiography in a different institution, where an ostial right coronary artery stenosis was diagnosed and she was listed for angioplasty, which she declined.
Transthoracic echocardiography demonstrated a Medtronic Hall valve with normal movement of the occluder, but with an elevated peak and mean transvalvular gradient (70 and 38 mm Hg respectively). We did not have a baseline recording for comparison.
Over the subsequent 2 years she became increasingly short of breath, while the echo findings remained stable. We decided to perform invasive hemodynamic assessment using a pressure wire (Radiwire, St Jude) to cross the valve and elucidate the gradient, and also to measure fractional flow reserve (FFR) across the right coronary ostial stenosis.
The patient was morbidly obese (BMI 32 kg/m2) but had refused catheterisation from the radial approach because of an unpleasant experience in another institution. We performed a right-sided femoral arterial puncture using standard techniques, gave 5000 units of unfractionated heparin via the arterial sheath, and advanced a 6F AL1 guide catheter to the ascending aorta under fluoroscopic guidance. The Radiwire was equalised and then was easily advanced across the prosthetic valve in the RAO projection (Figure 1).
We obtained simultaneous pressure readings from the LV and from the ascending aorta
These demonstrated much lower values than those recorded by echocardiography (peak gradient 27 mm Hg, mean 15 mm Hg), indicating that the findings were due to pressure recovery rather than to prosthetic valve malfunction.
We then used the same Radiwire to measure FFR across the ostial lesion (Figure 3) of the right coronary artery. We used intracoronary boluses of adenosine and demonstrated that the FFR was 0.89, well above the threshold for intervention.
We used intracoronary boluses of adenosine and demonstrated that the FFR was 0.89, well above the threshold for intervention.
Discussion
Before the widespread availability of Doppler echocardiography there were 3 ways to record a pressure trace in the left ventricle (LV) in patients with a prosthetic aortic valve: cross it with a catheter, perform a trans-septal puncture and measure the left ventricular LV pressure passing a catheter across the atrial septum, into the left atrium and then across the mitral valve, or record the intraventricular pressure through a trans-apical direct puncture of the LV(5), while a catheter in the aorta measured aortic pressure. All these methods are invasive, have a risk of fatal or severe complications and were performed infrequently.
After the first decade of use, it became clear that Doppler gradients across prosthetic valves - although easy to obtain, and reproducible in expert hands – have limitations(1, 6). A common and difficult conundrum arises when a patient with a prosthetic aortic valve replacement (AVR) presents with symptoms and the Doppler interrogation of the valve discloses a high pressure gradient. The difficulty is that normally functioning valves, mainly (but not exclusively) bi-leaflet and in small sizes, can display pressure recovery. This phenomenon leads to the measurement of a high velocity across the prosthetic valve by Doppler (which is translated into a high pressure drop by the Bernoulli equation), but this is not associated with abnormal turbulence or increased LV stroke work, so that the pressure ‘recovers’ a few centimetres above the valve.
It is difficult to justify sending such a patient for reoperation solely on the basis of the Doppler data, and the stakes are higher when the patient has comorbidities that would increase further the risk of reoperation. In such patients it is justifiable to pursue an invasive approach to record hemodynamic data which, together with imaging of the prosthetic valve, allow correct diagnosis and appropriate treatment.
The pressure wire has been used before to cross bi-leaflet AVRs(3, 4), but this is – we think – the first report of a single tilting disc prosthetic valve being crossed with a Radiwire. The Radiwire is widely available and accepted in catheter laboratories around the world for the assessment of coronary artery lesions, and it is important to increase awareness of other potential areas where it can provide unique and essential clinical information.
Acknowledgments
The authors of this manuscript have certified that they comply with the Principles of Ethical Publishing in the International Journal of Cardiology
References
1. Baumgartner H, Khan S, DeRobertis M, Czer L, Maurer G. Discrepancies between Doppler and catheter gradients in aortic prosthetic valves in vitro. A manifestation of localized gradients and pressure recovery. Circulation. 1990; 82:1467-75.
2. Rigaud, M, Dubourg O, Luwaert R, Rocha P, Hamoir V, Bardet J, Bourdarias JP. Retrograde catheterization of left ventricle through mechanical aortic prostheses Eur Heart J 1987; 8, 689-696.
3. Doorey AJ, Gakhal M, Pasquale MJ,Utilization of a Pressure Sensor Guidewire to Measure Bileaflet Mechanical Valve Gradients: Hemodynamic and Echocardiographic Sequelae. Catheter Cardiovasc Intervent 2006; 67:535–540.
4. Parham W,Shafei AE, Rajjoub H, Ziaee A, Kern MJ. Retrograde Left Ventricular Hemodynamic Assessment Across Bileaflet Prosthetic Aortic Valves: The Use of a High-Fidelity Pressure Sensor Angioplasty Guidewire Catheter Cardiovasc Intervent 2003; 59:509–513.
5. Walters DL, Sanchez PL, Rodriguez-Alemparte M, Colon-Hernandez PJ, Hourigan LA, Palacios IF. Transthoracic Left Ventricular Puncture for the Assessment of Patients With Aortic and Mitral Valve Prostheses: The Massachusetts General Hospital Experience, 1989–2000. Cathet Cardiovasc Intervent 2003;58:539–544.
6. Aljassim O, Svensson G, Houltz E, Bech-Hanssen O.Doppler-catheter discrepancies in patients with bileaflet mechanical prostheses or bioprostheses in the aortic valve position. Am J Cardiol. 2008; 102:1383-9.
7. Shewan LG and Coats AJ. Ethics in the authorship and publishing of scientific articles Int J Cardiol 2010;144:1-2
CONTACT
Prof. Dr. Ion Bruckner
office@srmi.ro
Tel: 021.315.65.11
Editorial Secretary
Dr. Roxana Pioaru
roxana.pioaru@srmi.ro
Secretariat organizatoric
Email: office@srmi.ro
Str. C-tin Noica, nr.134, Interfon 1, sector 6, Bucuresti
Tel : 021-3156511
Fax :021-3156537
Departament Comercial
Mihaela Dragomir
Email: mihaela.dragomir@ella.ro
Str. C-tin Noica, nr.134, Interfon 1, sector 6, Bucuresti
Tel : +40 753 359 693