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Factors that could affect the decision for CA or surgery for AF
Posted by DickI
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DickI
Factors that could affect the decision for CA or surgery for AF September 24, 2011 02:29AM |
Here is a short version of what follows:
Other things being equal*, these days, Afers might may more favorably on waiting to have a CA/surgery, to allow promising new, apparently efficacious treatments to become, through real-life experience, both safer and more effective. Developments in treatments that are less costly or risky than CA/surgery would also make waiting more attractive. These treatments would include new medications to to prevent stroke and to keep an Afer in NSR.
*I will hasten to add that an estimate of the effects of structural remodeling (i.e. scarring) be done... because, imperfect as it must be (unless an MRI is done), it will be most important in making this decision. Also, there seems to be increasing importance given to QOL (Quality of Life) in making this decision ... and as an outcome variable in comparing treatments.
_______________________________
The AFer who is thinking hard about whether to have a CA or other surgery or to wait will consider two groups of factors*.
One category would include factors that tend to be relatively static and relatively difficult to change. In other words, these factors are not going to change by themselves and they can be difficult to treat. An example would be the genetic component for AF, which could exert strong effects on some risk factors for AF, on the AFer's physiological reaction to stress and on his response to medications . and an environmental component, which could include his eating and exercise habits, his family family and financial situation, and access to medical care, the way he assesses risk, his tolerance for pain, and (are there others?).
*For another discussion of whether to have ablation or surgery, please see: [www.af-ideas.com]
The other category embraces factors that are in process, changing over time, and perhaps responsive to intervention or at least accommodation. It is this type of factor that I want to discuss because developments in the areas of medication and CA/surgical intervention have changed the playing field, and *perhaps* in more cases than previously, made waiting a better strategy.
[FYI: Surgical interventions would include CA (catheter ablation), which is endocardial, using either RF or cryo(tissue-freezing) energy, various versions of the Cox Maze (most of which are endocardial and use the heart-lung pump for at least part of the procedure).... plus so-called minimaze approaches (a term which can mean several things but which is usually a surgical PVI and not a replica of the Cox Maze), the hybrid or covergent variations (in which the surgeon begins by doing what he can and the EP finishes what is left to do, which will include finishing lines in areas that would be dangerous for the surgeon to apply energy), and the totally thoracoscopic maze (TTM), all which are endocardial and done on the beating heart .]
These more dynamic factors can be further divided into three groups: 1) patient characteristics that can affect treatment success; 2) developments in treatment that is usually considered to be more benign than surgical intervention (i.e. AR and upstream medications, trigger avoidance, lifestyle changes, supplements (which can improve electrolyte balance, mitochondrial health, and reduce oxidative stress), aggressive treatment of risk factors, such as HBP or sleep apnea; and 3) a continual and rapid progress in CA/surgical procedures, including availability of improved equipment and techniques and of more and more practitioners experienced and (presumably) skilled in their use (fueled in part by increasing awareness of the number of cases and the money to be made from them).
You can think these three groups of factors as constantly changing in their effects on positive or negative outcomes, and it will benefit the prospective patient and his or her doctor to evaluate each of the three groups in order to decide what to do and when.
I will briefly list some things in each category, and will leave it to others to add others that might be relevant to their own situation. (On the other hand, if the weather is beautiful as it is here, you might want to get yourself outside which is what I will be doing very soon!)
>>>Re the patient: The doctor and the patient must asses those characteristics which affect treatment success and mortality and decide what the level of these variables says about the timing of treatment.
If one is sure that the AF burden is low (no silent AF?), and that it is not contributing to other problems such as stroke risk or significant additional cardiac inflammation, then there may not be any hurry, at least until the time between episodes begins to shorten.
Recently there has been considerable attention directed at scarring which could result from: an inflammatory life-style (diet and especially endurance exercise) or as part of heart pathology (myocarditis) or from a debulking CA for non-paroxysmal AF) Recently there have been reports of the value of percentage of the heart's surface that is scar tissue in predicting CA success and possibly the ability of the heart to function when the person is old.
My impression is that at present, imaging that would show scarring (Delayed Enhancement MRI used by Dr Marrouche at U of Utah) is not being widely used yet, in spite of Dr Marrouche's efforts. So the patient and his doctor must do their best to assess the degree of scarring (or Stage as defined by Dr Marrouche or structural remodeling*) from the history of AF burden and from assessment of part and present sources of inflammation and from lab tests (the PLAC test may be more help than even the hs-CRP.
*There will be a chart giving an estimate of the times to various remodeling changes resulting from AF. I will include this at the end if I can get the image copied successfully.
>>>Re treatment while waiting for CA/surgery to improve: It is important to determine the probability that the patient can be kept: a) comfortable with an acceptable quality of life, and b) in NSR enough of the time to prevent an AF burden that would lower the probability of CA/surgery success (via the aforementioned remodeling).
If the Afer is doing OK on the waiting list with treatment that is keeping him in NSR, with an acceptable QOL (no intolerable short-term side effects), or a low probability that waiting a bit will create long-term effects that affect mortality, then there may be little need to rush into treatment.
Heading the list of things that can help the patient who has opted for waiting are new anticoagulants, which can make the patient stay in the CA/surgery waiting list more tolerable and safe. I am speaking, of course, of dabigatran but also of rivaroxaban. (These medications are not without drawbacks, including the fact that neither has an established protocol for reversing their effects in the case of a bleed.)
Antiarrhythmic drugs closest to the pharmacist's shelf are Vernakalent (current use restricted to conversion) and ranolazine, a more atrial-specific medication (which should mean fewer side effcts), which is in Phase III trials, with a completion date of 2013. The jury is still out on dronedarone, whose efficacy is lower than amiodraone and which has shown some rare but disturbing side effects:
The Black box warning [on the package insert] is as follows, "Warning: Heart failure: Multaq is contraindicated in patients with NYHA Class IV heart failure, or NYHA Class IIIII heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic. In a placebo-controlled study in patients with severe heart failure requiring recent hospitalization or referral to a specialized heart failure clinic for worsening symptoms (the ANDROMEDA Study), patients given dronedarone had a greater than two-fold increase in mortality. Such patients should not be given dronedarone."[4] The FDA alerted healthcare professionals to rare cases of severe liver damage associated with the use of dronedarone.[5]
Less costly and still under investigation, are the so-called upstream therapies, which include fish oil, AARBs and ACEIs, and statins. Their preventive potential presumably come from their anti-inflammatory action.
So, for the patient on the wait list, there are many things he can try, but so far, no approach or combination of approaches is expected to last more than a few years, and sometimes less. (For a much more extensive list of things to try, please see:
<[www.afibbers.org]>
Developments in CA and surgery: If there are treatment/practitioner combinations being developed but they are not quite to the level of acceptable where success- and complication rates are achieved, then, other things being equal, why not wait?
My sense is that a number of CA/surgery approaches or improvements are within a year to several years of reaching plateaus of development that represent a level of success that is acceptable, especially as compared to other treatment for AF/AFL.
Here I would point to the following:
1) Robotics slowly but surely equipment (software translating the operators movements to the robotic arms and hands), energy application, imaging, operator competence, cost ?? are improving ??
2) The use of a catheter/sensor/imaging/software package that can give the a quantitative and reliable measurement of contact force. This critical variable is correlated with lesion transmurality and therefore durability, but the the force-effect relationship is apparently different for each patient and the way to determine this is being worked out ?
3) TTM (the Totally Thoracoscopic Maze) surgery appears to be a way to effectively block or channel errant impulses before they can propagate into a sustained AR. More cases need to be collected to determine success and complication rates, and more surgeons need to go up the learning curve before this approach can be a significant process.
4) Cryotherapy has overcome obstacles to the point that its strong points (safety, and now with the right size balloon catheter, efficiency and speed) can become meaningful advantages. Phrenic nerve paralysis, although mostly reversible, is still a concern.
5) The hybrid or convergent approach to surgical intervention. Here are two variations on the theme of having the surgeon and the EP do what each can do best (or, do the best he can to make up for the omissions in the other's work, these omissions having to do the ability of the operatator/equipment to make all the necessary lesions safely and effectively. It can be a challenge to make the necessary lines while maneuver his energy application away from dangerous areas when the operator is limited to either endocardial or epicardial work.
[www.nmh.org]
[stanfordhospital.org]
I hope that taking a look at the groups of factors referred to above (patient factors reflecting AF progression, availability of treatments other than CA/surgery, and the status of improvements in CA/surgery) will help AFers to figure out what to do next.
Dick
______________________
ATRIAL REMODELING
4 Time Domains in Adaptations to Heart Rate
_______________________
Short term metabolic Ion concentrations Ion pump activities (seconds-minutes) Phosphorylation of ion channels
Moderate term Altered gene expression Synthesis/assembly
(hours-days)
Long-term (contractile remodeling) Hibernation
(weeks)
Very long-term (anatomic remodeling) Irreversible structural damage (months-years) (fibrosis, fatty generation, etc.)
___________________
Allessie,MA J Cardiovasc Electrophys. 1998-9(12):1378-1383
Other things being equal*, these days, Afers might may more favorably on waiting to have a CA/surgery, to allow promising new, apparently efficacious treatments to become, through real-life experience, both safer and more effective. Developments in treatments that are less costly or risky than CA/surgery would also make waiting more attractive. These treatments would include new medications to to prevent stroke and to keep an Afer in NSR.
*I will hasten to add that an estimate of the effects of structural remodeling (i.e. scarring) be done... because, imperfect as it must be (unless an MRI is done), it will be most important in making this decision. Also, there seems to be increasing importance given to QOL (Quality of Life) in making this decision ... and as an outcome variable in comparing treatments.
_______________________________
The AFer who is thinking hard about whether to have a CA or other surgery or to wait will consider two groups of factors*.
One category would include factors that tend to be relatively static and relatively difficult to change. In other words, these factors are not going to change by themselves and they can be difficult to treat. An example would be the genetic component for AF, which could exert strong effects on some risk factors for AF, on the AFer's physiological reaction to stress and on his response to medications . and an environmental component, which could include his eating and exercise habits, his family family and financial situation, and access to medical care, the way he assesses risk, his tolerance for pain, and (are there others?).
*For another discussion of whether to have ablation or surgery, please see: [www.af-ideas.com]
The other category embraces factors that are in process, changing over time, and perhaps responsive to intervention or at least accommodation. It is this type of factor that I want to discuss because developments in the areas of medication and CA/surgical intervention have changed the playing field, and *perhaps* in more cases than previously, made waiting a better strategy.
[FYI: Surgical interventions would include CA (catheter ablation), which is endocardial, using either RF or cryo(tissue-freezing) energy, various versions of the Cox Maze (most of which are endocardial and use the heart-lung pump for at least part of the procedure).... plus so-called minimaze approaches (a term which can mean several things but which is usually a surgical PVI and not a replica of the Cox Maze), the hybrid or covergent variations (in which the surgeon begins by doing what he can and the EP finishes what is left to do, which will include finishing lines in areas that would be dangerous for the surgeon to apply energy), and the totally thoracoscopic maze (TTM), all which are endocardial and done on the beating heart .]
These more dynamic factors can be further divided into three groups: 1) patient characteristics that can affect treatment success; 2) developments in treatment that is usually considered to be more benign than surgical intervention (i.e. AR and upstream medications, trigger avoidance, lifestyle changes, supplements (which can improve electrolyte balance, mitochondrial health, and reduce oxidative stress), aggressive treatment of risk factors, such as HBP or sleep apnea; and 3) a continual and rapid progress in CA/surgical procedures, including availability of improved equipment and techniques and of more and more practitioners experienced and (presumably) skilled in their use (fueled in part by increasing awareness of the number of cases and the money to be made from them).
You can think these three groups of factors as constantly changing in their effects on positive or negative outcomes, and it will benefit the prospective patient and his or her doctor to evaluate each of the three groups in order to decide what to do and when.
I will briefly list some things in each category, and will leave it to others to add others that might be relevant to their own situation. (On the other hand, if the weather is beautiful as it is here, you might want to get yourself outside which is what I will be doing very soon!)
>>>Re the patient: The doctor and the patient must asses those characteristics which affect treatment success and mortality and decide what the level of these variables says about the timing of treatment.
If one is sure that the AF burden is low (no silent AF?), and that it is not contributing to other problems such as stroke risk or significant additional cardiac inflammation, then there may not be any hurry, at least until the time between episodes begins to shorten.
Recently there has been considerable attention directed at scarring which could result from: an inflammatory life-style (diet and especially endurance exercise) or as part of heart pathology (myocarditis) or from a debulking CA for non-paroxysmal AF) Recently there have been reports of the value of percentage of the heart's surface that is scar tissue in predicting CA success and possibly the ability of the heart to function when the person is old.
My impression is that at present, imaging that would show scarring (Delayed Enhancement MRI used by Dr Marrouche at U of Utah) is not being widely used yet, in spite of Dr Marrouche's efforts. So the patient and his doctor must do their best to assess the degree of scarring (or Stage as defined by Dr Marrouche or structural remodeling*) from the history of AF burden and from assessment of part and present sources of inflammation and from lab tests (the PLAC test may be more help than even the hs-CRP.
*There will be a chart giving an estimate of the times to various remodeling changes resulting from AF. I will include this at the end if I can get the image copied successfully.
>>>Re treatment while waiting for CA/surgery to improve: It is important to determine the probability that the patient can be kept: a) comfortable with an acceptable quality of life, and b) in NSR enough of the time to prevent an AF burden that would lower the probability of CA/surgery success (via the aforementioned remodeling).
If the Afer is doing OK on the waiting list with treatment that is keeping him in NSR, with an acceptable QOL (no intolerable short-term side effects), or a low probability that waiting a bit will create long-term effects that affect mortality, then there may be little need to rush into treatment.
Heading the list of things that can help the patient who has opted for waiting are new anticoagulants, which can make the patient stay in the CA/surgery waiting list more tolerable and safe. I am speaking, of course, of dabigatran but also of rivaroxaban. (These medications are not without drawbacks, including the fact that neither has an established protocol for reversing their effects in the case of a bleed.)
Antiarrhythmic drugs closest to the pharmacist's shelf are Vernakalent (current use restricted to conversion) and ranolazine, a more atrial-specific medication (which should mean fewer side effcts), which is in Phase III trials, with a completion date of 2013. The jury is still out on dronedarone, whose efficacy is lower than amiodraone and which has shown some rare but disturbing side effects:
The Black box warning [on the package insert] is as follows, "Warning: Heart failure: Multaq is contraindicated in patients with NYHA Class IV heart failure, or NYHA Class IIIII heart failure with a recent decompensation requiring hospitalization or referral to a specialized heart failure clinic. In a placebo-controlled study in patients with severe heart failure requiring recent hospitalization or referral to a specialized heart failure clinic for worsening symptoms (the ANDROMEDA Study), patients given dronedarone had a greater than two-fold increase in mortality. Such patients should not be given dronedarone."[4] The FDA alerted healthcare professionals to rare cases of severe liver damage associated with the use of dronedarone.[5]
Less costly and still under investigation, are the so-called upstream therapies, which include fish oil, AARBs and ACEIs, and statins. Their preventive potential presumably come from their anti-inflammatory action.
So, for the patient on the wait list, there are many things he can try, but so far, no approach or combination of approaches is expected to last more than a few years, and sometimes less. (For a much more extensive list of things to try, please see:
<[www.afibbers.org]>
Developments in CA and surgery: If there are treatment/practitioner combinations being developed but they are not quite to the level of acceptable where success- and complication rates are achieved, then, other things being equal, why not wait?
My sense is that a number of CA/surgery approaches or improvements are within a year to several years of reaching plateaus of development that represent a level of success that is acceptable, especially as compared to other treatment for AF/AFL.
Here I would point to the following:
1) Robotics slowly but surely equipment (software translating the operators movements to the robotic arms and hands), energy application, imaging, operator competence, cost ?? are improving ??
2) The use of a catheter/sensor/imaging/software package that can give the a quantitative and reliable measurement of contact force. This critical variable is correlated with lesion transmurality and therefore durability, but the the force-effect relationship is apparently different for each patient and the way to determine this is being worked out ?
3) TTM (the Totally Thoracoscopic Maze) surgery appears to be a way to effectively block or channel errant impulses before they can propagate into a sustained AR. More cases need to be collected to determine success and complication rates, and more surgeons need to go up the learning curve before this approach can be a significant process.
4) Cryotherapy has overcome obstacles to the point that its strong points (safety, and now with the right size balloon catheter, efficiency and speed) can become meaningful advantages. Phrenic nerve paralysis, although mostly reversible, is still a concern.
5) The hybrid or convergent approach to surgical intervention. Here are two variations on the theme of having the surgeon and the EP do what each can do best (or, do the best he can to make up for the omissions in the other's work, these omissions having to do the ability of the operatator/equipment to make all the necessary lesions safely and effectively. It can be a challenge to make the necessary lines while maneuver his energy application away from dangerous areas when the operator is limited to either endocardial or epicardial work.
[www.nmh.org]
[stanfordhospital.org]
I hope that taking a look at the groups of factors referred to above (patient factors reflecting AF progression, availability of treatments other than CA/surgery, and the status of improvements in CA/surgery) will help AFers to figure out what to do next.
Dick
______________________
ATRIAL REMODELING
4 Time Domains in Adaptations to Heart Rate
_______________________
Short term metabolic Ion concentrations Ion pump activities (seconds-minutes) Phosphorylation of ion channels
Moderate term Altered gene expression Synthesis/assembly
(hours-days)
Long-term (contractile remodeling) Hibernation
(weeks)
Very long-term (anatomic remodeling) Irreversible structural damage (months-years) (fibrosis, fatty generation, etc.)
___________________
Allessie,MA J Cardiovasc Electrophys. 1998-9(12):1378-1383
|
researcher
Re: Factors that could affect the decision for CA or surgery for AF September 26, 2011 01:56AM |
|
Re: Factors that could affect the decision for CA or surgery for AF September 26, 2011 11:20AM |
Registered: 6 years ago Posts: 18,881 |
Dick this is a good assessment of considerations.
Missing is the consideration for Adverse Effects as a result of an invasive procedure. It's incomplete to recommend a procedure without also identifying the potential problems which should be discussed with the EP or Cardiac Surgeon as a matter of course in the pre-surgical review called Informed Consent.
Lets start a list of what those considerations might be based on reports here and what we know might occur. It would also be useful to learn what the remedy is for any or several of the potential risks should they occur. While typically, the procedure is uneventful, a complication can be life-changing and devastating not to mention expensive.
Its important to know how benign the adverse effects or complications might be should they occur.
1. Radiation exposure during the procedure and from the diagnostics required
2. Anesthesia risks any time there is anesthesia, there are risks involved
3. Pulmonary vein stenosis not as prevalent currently as in former years but they still check for it post-ablation
4. Damage to the phrenic nerve
5. Damage to the vagus nerve
6. Pericarditis/endocarditis/pericardial effusion
7. Tamponade or puncture through the heart wall How exactly is that resolved?
8. Atrio-esophageal fistulas serious consequences
9. Life-long use of an anti-coagulant if the LAA is rendered nonfunctional
There are undoubtedly more. What else can we add that deserves consideration?
It just makes sense to know all of the relevant details.
Jackie
Missing is the consideration for Adverse Effects as a result of an invasive procedure. It's incomplete to recommend a procedure without also identifying the potential problems which should be discussed with the EP or Cardiac Surgeon as a matter of course in the pre-surgical review called Informed Consent.
Lets start a list of what those considerations might be based on reports here and what we know might occur. It would also be useful to learn what the remedy is for any or several of the potential risks should they occur. While typically, the procedure is uneventful, a complication can be life-changing and devastating not to mention expensive.
Its important to know how benign the adverse effects or complications might be should they occur.
1. Radiation exposure during the procedure and from the diagnostics required
2. Anesthesia risks any time there is anesthesia, there are risks involved
3. Pulmonary vein stenosis not as prevalent currently as in former years but they still check for it post-ablation
4. Damage to the phrenic nerve
5. Damage to the vagus nerve
6. Pericarditis/endocarditis/pericardial effusion
7. Tamponade or puncture through the heart wall How exactly is that resolved?
8. Atrio-esophageal fistulas serious consequences
9. Life-long use of an anti-coagulant if the LAA is rendered nonfunctional
There are undoubtedly more. What else can we add that deserves consideration?
It just makes sense to know all of the relevant details.
Jackie
|
McHale
Re: Factors that could affect the decision for CA or surgery for AF September 26, 2011 12:49PM |
|
researcher
Re: Factors that could affect the decision for CA or surgery for AF January 19, 2012 02:33AM |
Dick,
I think further comments are needed on robotics given what was reported to the FDA. Two systems are available at various centers throughout the nation. One is based on controlling the cables that steer the catheters (Hansen Medical Sensei system) and another one based on magnetic steering of catheters with no cables (Stereotaxis Niobe system).
Adverse events are reported to the FDA and filed under the MAUDE database. Hansen reported six deaths directly associated with usage of the Sensei system in 2011. Five from atrial-esophageal fistulas, and one from retroperitoneal injury. Given the small number of procedures performed (looks like around 2400 or so annually on the system), the number is beyond bad when compared to Cappato's survey results. I have in the recent past warned readers when they visit centers with the system. The latest reports is beyond my worse fears.
The magnetic system has no reported deaths. One death was reported early on when the clinician switched from the magnetic system to a cryo catheter and perforated the heart with the cryo catheter.
I think further comments are needed on robotics given what was reported to the FDA. Two systems are available at various centers throughout the nation. One is based on controlling the cables that steer the catheters (Hansen Medical Sensei system) and another one based on magnetic steering of catheters with no cables (Stereotaxis Niobe system).
Adverse events are reported to the FDA and filed under the MAUDE database. Hansen reported six deaths directly associated with usage of the Sensei system in 2011. Five from atrial-esophageal fistulas, and one from retroperitoneal injury. Given the small number of procedures performed (looks like around 2400 or so annually on the system), the number is beyond bad when compared to Cappato's survey results. I have in the recent past warned readers when they visit centers with the system. The latest reports is beyond my worse fears.
The magnetic system has no reported deaths. One death was reported early on when the clinician switched from the magnetic system to a cryo catheter and perforated the heart with the cryo catheter.
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