Archive for November, 2009
Weighing Your Surgical Options
I have over the last several blogs pointed out how ideas, when they come to medicine, need to be rigorously tested. I want to travel back to the original question which is “who needs coronary bypass or angioplasty to manage their coronary artery disease?” It is important to remember as I have blogged before that management of this illness is medically based. Patients need to stop smoking, manage their cholesterol with statins and diet, exercise, control diabetes and high blood pressure. At times, it becomes necessary to provide revascularization because primarily chest pain or angina is life limiting. This means that your lifestyle is hindered. This equation is different for a 45 year old man than an 85 year old man and realistic goals need to be put in place.
Angioplasty can often be easily done but does not provide a mortality benefit or a prevention of myocardial infarction. It is a treatment of symptoms that do not respond to medical management. Surgery is much the same. However, if you have left main disease or poor heart function with three vessel disease you will live longer if you have bypass surgery instead of medical management alone.
The method of surgery should be discussed with your surgeon and depends on the placement of your arteries, and the condition of the segments needed for bypass targets and other technical concerns. Also important is the surgeon’s case level and whether he or she is comfortable with the procedures required.
The concept of “minimally invasive surgery” and robotic surgery is untested at this time and is purely a variation that requires a good hard look. It was widely felt that off pump surgery would be better but that is not the case. Robots are very expensive and it remains to be seen whether the whole idea is worth the trouble and expense.
One further point about the ROOBY study is that it again proved the point about getting a complete operation. What I mean by that is that all the vessels that need to be fixed need to be fixed. Although that sounds silly, angioplasty will often target only certain arteries and “manage” the others. Off pump did a poorer job of bypassing all the vessels needed. This approach leads to worse outcomes with increased need for reoperation, angina and death. As always you should have a thorough understanding of what is wrong and what your options are. If you don’t get the answers you need continue to ask until you do.
Off Pump Study Results Recently Revealed
Published in the New England Journal of Medicine earlier this month were the findings of the ROOBY study (NEJM 2009; 361:1827-37). The Randomized On/Off Bypass study group was comprised of 18 VA medical centers and was conducted from February 2002 to May 2008. More than 9,600 patients were screened for entry into the study; 7,460 were excluded because they had poor target vessels, would not give consent, or their surgeons were not a participant; 2,203 were randomized and 1,104 were assigned to off pump, while 1,099 were assigned to on pump randomly. Of the1,104 randomized patients to off pump, 137 needed the bypass machine for the operation to be completed. Interestingly, of the 1,099 patients who were randomized to on pump operations, 43 were converted to off pump.
The results showed there was no significant difference in the 30 day composite outcome–7.0% for off pump and 5.6% for on pump. The composite was death or the complications of reoperation, new mechanical support, cardiac arrest, coma, stroke, or renal failure.
Further, the results for the one year outcome were worse: off pump 9.9% vs. 7.4 % for on pump. The 1-year composite was death from any cause, repeat revascularization procedure, or a nonfatal myocardial infarction.
Follow up angiograms revealed the overall patency rate of the bypass grafts was 82.6% in the off pump group and 87.8% in the on pump group. The off pump group had a higher proportion of arteries not able to be bypassed 17.8% vs. 11.1%. There were no differences in neurocognitive outcomes or short term use of major resources.
Overall, this study showed that patients who had the standard operation did better. This result is similar to the findings of a recent Meta analysis and of several other smaller studies. Single center and single surgeon studies fare better and reflect different surgical abilities but do not reflect “real world” outcomes. In this study, you needed to have done at least 20 off pump cases to be considered an investigator.
There are several problems with this study – the most glaring is that it is almost exclusively an all-male study. Remember it was done at the VA and in spite of the different composition of our armed forces at the present time most women who are veterans are not at the age to need this type of medical care. These results can not be generalized to women who often have poorer bypass targets and would be expected to have poorer outcomes.
Next…putting this information in context.
Off the Beating Path
Off-pump coronary artery bypass surgery was developed during the 1990s. The reason that the heart-lung machine is necessary during the operation is that it provides blood and oxygen to the body and brain while the heart is stopped. The heart needs to be still so that the surgeons can sew the veins and arterial conduits on to the arteries that need to be bypassed. In the best of circumstances this is complicated. The heart arteries are buried under the pericardial fat on the surface of the heart. They are 1-2 mm in diameter without blood. Surgeons wear special glasses called loops to provide powerful magnification so they can see these structures to sew to. The surgery requires the area to be motionless so this can be accomplished. This is why the heart is stopped.Off-pump surgery was promoted as a way to possibly manage some of the consequences of coronary bypass surgery using a bypass machine. These, in theory, included better operative mortality, improved late mortality, less perioperative morbidity, better neurocognitive outcomes, less resource utilization and the ability to operate on high risk patients with improved outcomes.
The technique was originally the brainchild of an ah-ha moment. A surgeon realized that when one small area of the heart was touched that it did not move. He basically took a spoon and cut a hole in the center of it, pressed it over the area of artery that he wanted to operate on and it was still enough to accomplish the sewing that needed to be done.
The medical device companies put their best minds on it and soon a wide variety of devices were available to do this work. All, I might add, significantly more complicated and expensive than a spoon with a hole cut in it. Most involve some degree of suction on the heart to stabilize and position it while it is allowed to beat. There is a learning curve to this and not all surgeons do it. Some started doing it exclusively and some never do it. Some operations are done both ways to lessen the amount of time on the bypass machine.
But does it matter? Does it provide any benefit? This is where research comes in. A comparison study between the two techniques was performed and reported recently. In my next blog, I will again point out that if you ask a question you may be surprised at the answer.
The History of Coronary Artery Bypass Surgery
Coronary artery bypass operations are again in the news. This operation is the most performed operation in the world and dates back to the early 1960’s. We are still trying to improve upon it and enhance the results we can achieve.
Open heart surgery dates back to the early 1950’s when Dr. John Lewis repaired an atrial septal defect (a hole between the top parts of the heart known as the atrium, a birth defect). He did this by cooling the 5 year old girl’s heart. At about the same time, the heart-lung machine was first used by Dr. John Gibbon also to repair an atrial septal defect.
In 1956, Dr. Walton Lillehei corrected a patient with mitral regurgitation under direct vision using the heart lung machine. He went on to develop some of the new artificial heart valves and the pioneering techniques for this type of surgery.
In 1946, Dr Arthur Vineberg developed a technique to implant the mammary artery directly into the myocardium, allowing it to collateralize the vessels to the front of the heart. Roughly 5,000 Vineberg procedures took place between 1950 and 1970.
Dr. Vasilii Kolessov, a Russian cardiac surgeon, performed the first internal mammary to coronary artery anastomosis in 1964. Dr Rene Favaloro, a physician at the Cleveland Clinic, performed the first saphenous vein operation by harvesting a vein from a patients leg and bypassing the right coronary artery in 1967. Soon after Dr. Dudley Johnson in Milwaukee used the vein grafts to bypass the left coronary arteries.
Bypass surgery was out of the gate and to this day has not changed much in technique. It is invasive and the heart lung machine is believed to be detrimental at times to patients. Over the years the ability of surgeons has increased so that they now routinely perform this operation on sicker and older patients and to continue to drive the mortality to the operation to 1.6%.
Can this operation be done in a safer manner? Are the alternatives better?
Next…the alternative.
Study Looks into the Risk of Complications by Attending Physicians After Performing Nightime Procedures
Recently, data has come forward, which illustrates how doctors who are no longer in training function. Although doctor hours are now rigorously documented once in private practice, doctors are no longer so regimented.
Published in JAMA 2009;302: 1565-1572 and titled Risks of Complications by Attending Physicians After Performing Nighttime Procedures this article goes on to describe what could be guessed but now becomes more clear. This study compared 919 surgical and 957 obstetrical post- nighttime procedures that were matched with 3,552 and 3,945 control procedures respectively. The complications were almost doubled from 3.4% to 6.2%. Not surprisingly, the less sleep the more complications occurred.
This study did not take into account those physicians that are sleep deprived by fielding night time calls from hospitals and patients and did not take into account that night time procedures are often much more complicated and emergent than daytime elective procedures.
Also, cognitive ability and surgical ability are in some ways dissimilar and more difficult to quantify. Mistakes can be made in medicine ordering and misunderstandings occur in communications between medical personnel, which can and does often impact patient care. None of this is regulated and at the end of the article there is a call for greater attention by hospital administrators to regulate night time work.
Realistically, it is not possible to regulate private practice work hours and alarmingly the medical workforce is aging quickly and may continue to see a brain drain as students steer themselves into more stable work environments.
The shadow of Libby Zion reminds physicians that we have to care for ourselves to give the best care to our patients.
The Libby Zion Law
Sidney Zion who died recently began a crusade against what he felt was his daughter’s death due to inadequate staffing and negligence. The doctors had mixed two drugs that can have unfortunate consequences and in this case death. This is known as the serotonin syndrome. This occurred through lack of knowledge or by mistake because the levels of training were not adequate. The 36 hour shift became a flash point in the case.
In 1986 a grand jury was impaneled to consider murder charges. The grand jury declined to indict them for murder. There were trials both malpractice and civil. There were multiple state medical board hearings. At the conclusion the doctor’s insurance company paid $375,000 for “pain and suffering” to the family. The two residents were censured for acts of gross negligence. This did not affect their right to practice. One of them, Gregg Stone, is a prominent cardiovascular researcher who still is at Columbia in New York.
As a direct result of this case and the crusading efforts of Sidney Zion, the New York State Department of Health Code, Section 405, became known as the Libby Zion law. It limits the amount of resident work to 80 hrs per week. In 2003, The Accreditation Council for Graduate Medical Education adopted similar regulations for all medical training programs in the United States.
This change has led to unintentional consequences. It has led to a different philosophy among medical graduates that while not wrong is different than the philosophy of those that came before Libby. Many graduates now want limited work hours in private practice and extensive time off that older physicians find alarming. This limitation of work leads to the worsening of an already acute lack of physicians at times. This coupled with the momentous changes that confront us as we move to health care reform and the decreasing numbers of new physicians may led to doctor shortages especially in those areas of the United States that are chronically underserved.
Next…what about doctors in private practice?
The Case of Libby Zion and What She Means to the Medical Community
Sometimes the death of an individual has long lasting permanent consequences far removed from the tragedy for the family. Physicians who presently are in practice are dated from either before or after the death of this individual. Who was Libby Zion and why does she mean so much to physicians?
There is now a profound difference in the way all doctors are trained that can be dated to after Libby Zion’s death. Although there is a touch of “when I was a child, I walked to school through 10-foot high snow drifts in the sub-zero temperature” when doctors my age trained we worked until we were finished. What did that mean? I worked for thirty-six hours and was off 12 hours. The off 12 occurred if you were finished with your patient care responsibilities. This was not all the time but it was when you were on primary hospital training and could last for three months at a time before you were rotated to another service with less time requirements.
In practice this prepared us for what can sometimes happen. That is having to work through the night and then the next day. Whether this was sound theory or practice was never really questioned. It was the “way it had always been done.”
Libby Zion was an 18 year old freshman at Bennington College with a history of depression. She was admitted to the New York Hospital Cornell Medical Center on March 4, 1984 during the evening shift. She had a history of ongoing depression and was complaining of fever, agitation and jerking motions of her body. No diagnosis was provided but she was admitted to the ward and cared for by two new physicians, one with eight months of experience and one with twenty months. She was given a pain killer and a sedative and was felt to have a viral syndrome and that “she was acting out.”
At 3:00 am , she became more agitated and the doctor ordered restraints and an antipsychotic to be injected. She was not seen again. At 6:30am in the morning, her temperature was 107.6 and soon after she suffered a cardiac arrest and died. It might have ended there except Libby’s father was Sidney Zion, a journalist.
Next…the long battle.
Look into Stent Options Before undergoing Catheterization
I will like to elaborate on a point I made in my last blog. I want to talk about the issue of patients who are undergoing cardiac catheterization for preoperative evaluation. These patients may or may not have evidence for cardiac disease either by stress testing or symptoms. What is done after the cath is critical and the need for non-cardiac surgery must be thoroughly discussed and analyzed before proceeding with any revascularization by stenting or coronary artery bypass surgery.
A study concerning this issue was just published in the journal Heart 2009; 95:1303-1308. It is titled Non-Cardiac Surgery and Antiplatelet Therapy Following Coronary Artery Stenting. This article reports a Meta analysis of this common clinical scenario. A Meta analysis is not a study. It is a statistical analysis of like studies that are melded together to seek out common similarities and differences in treatments. Although they often don’t fully answer questions, they point us in directions to ask better questions and can lead to meaningful dialogue.
This report covers 50,000 patients and finds that undergoing non-cardiac surgery while on low dose aspirin i.e. 81 mg. increases the risk of minor bleeding by 50%. There is no change in major bleeding except in prostate and neurosurgery procedures.
The use of Plavix during surgery increases the risk of major bleeding.
In previous blogs, I have discussed the use of these agents after stenting. If you have a non-drug stent, the current recommendations are to take aspirin and Plavix for a minimum of a month but if possible for one year. If you have a drug stent, the recommendation is to take aspirin and Plavix for one year. If you were stented for a myocardial infarction or unstable angina then the recommendations are one year regardless of what stent you have implanted.
In my patients depending on what type of surgery is needed, I often do not repair the coronary blockages until after surgery. Many operations can be done safely with aspirin and beta-blocking drugs such as Toprol and atenolol. There are many options but if not discussed this clinical scenario can lead to disaster. It is always necessary to thoroughly discuss all aspects of your medical condition with all your doctors.
Patient compliance is key
The four year follow up of the study known as TYCOON or Two-Year Clopidogrel Need registry was published online September 28, 2009 in the American Journal of Cardiology. This study was not randomized; it was a registry study, meaning that consecutive patients were enrolled and then compared to another group. 897 consecutive patients who underwent stenting in 2003 and 2004 were enrolled and three groups were created. 450 patients had bare metal stents and took dual antiplatelet therapy or DAPT for one month and then aspirin. 173 patients who had drug eluting stents took DAPT for 12 months and then aspirin. 274 patients who had drug eluting stents took DAPT for 24 months and then aspirin.
During follow up, the bare metal group had 3 stent thrombosis events one acute, one subacute (<30 days) and one late (30 days -1 yr). The 1 yr group had 1 subacute and 4 very late (>1 yr). The 24 month group had 1 subacute and no other thrombosis events.
This was not randomized study and not powered to provide true statistical answers. It is however compelling data. The DAPT study will have over 20,000 patients and is powered to show any difference in rates of stent thrombosis and major cardio and cerebrovascular events. The primary safety endpoint is major bleeding.
TYCOON does however once again point out how important patient compliance with this medicine is. If you have a stent it is imperative not to stop either aspirin or Plavix until your cardiologist says so, no matter what other doctors or people may tell you. Cleaning your teeth is important but not a reason to die. Before any cardiac procedure it is important to tell your doctors any future surgery that maybe needed or planned so that proper choices can be made.
Stenting coronary arteries can be a significant benefit to patients. It is however one area of medicine that requires significant input and cooperation. As new stents and drugs are developed all this will change, for now this is all we know.
Drugs for Life
As I have discussed before, one of the issues that we as Interventional Cardiologists deal with is how long Plavix should be taken with aspirin when patients have a drug eluting stent. The reason this problem is vexing is that these stents, and not “bare” metal or nondrug stents, can abruptly close; and when the stents do, it always causes a heart attack and can lead to death, in many cases. At the present time, the guidelines from the American College of Cardiology suggest that patients stay on aspirin and Plavix for a minimum of 12 months. Additionally, they feel the same way about bare metal stents. This is different than the original FDA guidelines which said that if you had a Cypher stent you needed three months of DAPT (dual antiplatet therapy) and if you had a Taxus stent you needed six months of DAPT. If you had a bare metal stent the recommendation was one month. It should be mentioned at this point that the expectation is aspirin for life.
I personally feel that all patients who have coronary disease and stents should stay on these drugs for life. I feel that they have a disease process that leads to further problems and will be benefited for the long term. Soon the cost will be lessened by the generic Plavix that we will see in 2011. At this juncture we have no data on what to do.
Recently, a study started funded by the device companies and Harvard to determine whether 30 months is better than one year of therapy. We will participate in this study. Patients will be asked to divide into two groups randomly. One group will take placebo after one year of Plavix and one will take Plavix continuously for 30 months. At the end of the study we will know if everyone should remain on Plavix. It will take nearly five years to do this study. This is what I have referred to as moving target medicine. Will anyone care? Will anyone still be on Plavix or will we have moved to one of the other Plavix like drugs of which there are already two others.
Next… the signals that long term Plavix may be best.
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