Frequently Asked Questions
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In medical literature Operator competence has traditionally been alluded to as a “soft variable” it is however the opinion of this site that when it comes to complex percutaneous coronary intervention operator excellence may actually be a key factor governing outcomes.
The NOCOBYE™ Physician Par excellence™ (PPEx™) is an interventional cardiologist who on the basis of experience and training has developed exceptional faculties to seamlessly perform the coronary stenting procedure in settings where many cardiologists would consider referring the patient for coronary artery bypass surgery/open heart surgery.
The typical Interventional Cardiologist who performs Coronary stenting may not think outside the box and operates within the confines of the customary approach which dictates sending most patients with multiple coronary blockages and Left Main coronary artery blockages for Open Heart/Coronary Artery Bypass Graft Surgery.
Whereas the NOCOBYE™ Physician Par Excellence™ (PPEx™) is handpicked to be an operator who is already ahead of the curve and thinking today what tomorrow will bring to his patients. He is thus drawing upon the latest supporting scientific data in favor of non surgical treatment of complex CAD and treating his patients differently from the guideline driven average Interventional Cardiologist.
To be able to accomplish this such a Physician Par Excellence™ (PPEx™) is highly versatile and is facile with use of latest gadgetry and techniques including use of atherectomy and the safe non surgical use of the miniature cardiac assist devices.
Typically such Interventional cardiologists’ are also competent in managing Chronic Total Occlusion (CTOs) and maintain a high procedural volume.
CHIP stands for Complex High risk Indicated Procedure.
This is just another fancy name for High Risk Stenting/PCI with or without the use of a miniature cardiac assist device.
A number of factors when taken into account can make stenting more complex and these include; advanced age, kidney disease, increased complexity of blockages including chronic total occlusion (CTOs), previous bypass surgery and advanced congestive heart failure.
Operators involved with CHIP typically meet the qualifications enunciated in the What is a Physician of Excellence™ section of FAQs.
Coronary arteries are a crownlike network of blood vessels that carry blood continually to the heart muscle (myocardium). The myocardium extracts several fold more oxygen from the blood that circulates through it than any other organ in the body and is therefore very susceptible to damage(heart attack) because of a lack of adequate blood supply caused by a blocked coronary artery.
Coronary artery disease is plaque buildup in the arteries that supply blood to the heart muscle; this plaque build up impedes oxygen supply to the heart muscle causing a wide spectrum of clinical syndromes ranging from stable angina, unstable angina and minor heart attack(NSTEMI) to a massive heart attack(STEMI).
When plaque builds up in more than one coronary artery it is called Multi vessel coronary artery disease. When all three major coronary arteries are blocked it is called triple vessel coronary artery disease. The two terms are frequently used interchangeably. In the past treatment of Multivessel coronary artery disease was exclusively by open heart/coronary bypass graft surgery but currently in the right hands most cases of Multivessel coronary artery disease can be treated using stents without open heart surgery.
Left Main is the very beginning portion of the Left Coronary artery before it divides into its two main branches namely the Left Anterior descending and the Circumflex. It is the equivalent of a “house water main” and therefore when blocked can cause a very large segment of the heart muscle to starve for oxygen.
Importantly for the Interventional cardiologist it is a very unforgiving part of the coronary circulation to work on as there is no margin for error.
Therefore historically Left Main Coronary artery blockages presented a “no fly “ zone for stenting but now with the advent of miniature cardiac assist devices Left Main stenting in the right hands is a viable option supported by concrete scientific data.
Left main coronary blockages can exist by themselves or more usually as part of Multivessel coronary artery disease.
A CTO or chronic total occlusion is a long standing 100% blockage of a Coronary artery; typically such a blockage has already caused some damage to the heart muscle from a previous heart attack which may even have been silent and therefore unbeknownst to the patient.
A hallmark of a CTO is development of “natural bypasses” called collaterals. These collaterals are new arteries that spontaneously open up and bring blood from other non diseased coronary arteries to the heart muscle subtended by the CTO.
These collaterals protect the heart from further damage.
Fixing a CTO is therefore a subject of intense debate in the world of Interventional Cardiology and thus far the data regarding survival benefits from fixing such blockages is mixed.
There is however an improvement in symptoms of angina leading to lifestyle enhancement which maybe an important consideration in younger more active patients.
Addressing a CTO by stent procedure requires dedication and special skill sets which will be further addressed in the FAQ # 25.
Syntax score is a widely accepted grading algorithm to determine the severity and complexity of coronary blockages and is determined by the cardiologist based on a review of the Coronary angiogram. Amongst other characteristics, the Syntax score takes into account the location, length, tortuoisty, degree and calcification (hardening) of the arteries.
The higher the Syntax score the more dexterous the operator must be to deliver optimal outcomes.
A more recent update of the original Syntax score is the Syntax II score based on the Syntax II study.
The term Stable angina refers to a pressure like chest discomfort that may radiate to the jaw and the left arm; typically it comes on with exertion and is relieved by rest. However there are many atypical presentations including abdominal discomfort, back pain and toothache that have been recorded.
It is the classical symptom of a coronary blockage impeding flow of oxygen to the heart muscle and should be taken as a serious signal to obtain urgent medical care.
Typically stable angina prompts a cardiologist to order a stress test which if abnormal leads to a coronary angiogram which in turn can lead to simultaneous stent placement or a recommendation for coronary bypass surgery depending upon operator expertise and preference.
When angina starts coming on with decreasing effort, increasing frequency or even at rest it is called Unstable Angina that could rapidly evolve into a mild or even a full blown heart attack.
Typically Unstable angina results from rapid worsening of a pre-existing moderate to severe coronary blockage with or without spasm (Prinzemetal’s Angina) causing severe oxygen deprivation to the heart muscle.
As such unstable angina warrants immediate medical attention and a 911 call maybe a prudent choice.
A heart attack is further evolution of stable or unstable angina into the stage of actual damage to the heart muscle; when such damage is mild it is called NSTEMI and when it is a full blown massive heart attack it is called a STEMI. The typical cause is rapid worsening of a pre existing coronary blockage due to formation of a blood clot leading to total or near total sudden interruption of oxygen supply to the heart muscle.
A heart attack usually results in severe chest pressure sometimes with but mostly without physical effort.
The chest pressure or pain typically radiates to the neck and left arm and is not relieved with rest. As such it warrants an immediate 911 call.
While waiting for help an aspirin may be beneficial.
All patients with a full blown heart attack (STEMI) and most with mild heart attacks (NSTEMI) require urgent medical attention and should be whisked to a cardiac catheterization laboratory for an emergency coronary angiogram upon emergency room arrival.
Almost all patients having a massive heart attack/STEMI receive an emergency stent.
However the fashion in which a patient having a mild heart attack/NSTEMI is handled can vary widely depending upon the hospital culture and operator expertise.
Thus many patients with a mild heart attack and multiple blockages end up receiving CABG/OHS instead of Coronary stenting.
Unstable angina, NSTEMI and STEMI are sometimes collectively bundled together as “Acute coronary syndromes” and are all manifestations of severe oxygen deprivation of the heart muscle due to rapidly evolving coronary blockage causing near total or total cessation of blood supply.
Cardiac arrest is a term used to describe the condition in which the heart suddenly stops beating and pumping blood.
The usual cause is a cardiac arrhythmia called Ventricular fibrillation which could occur in the setting of an acute coronary syndrome or in the aftermath of damage and scarring of the heart muscle that results from a past untreated heart attack.
There are many other causes of ventricular arrhythmias that are not germane to this discussion.
Heart failure is a term used to describe the clinical syndrome that results from backing up of blood in the lungs and rest of the body; typical manifestations of Heart failure are shortness of breath and swelling of the legs. There are many causes of heart failure but the one germane to this discussion is the heart failure that results from untreated underlying coronary blockages or as a result of previous damage to the heart muscle (heart attack) due to such blockages. At times heart failure can manifest simply as weakness and tiredness without much congestion of lungs or swelling of legs (so called forward failure).
The terms cardiac catheterization and coronary angiogram are at times used interchangeably. Both terms allude to a simple and safe test that involves advancing to the heart a narrow flexible tube called a coronary catheter.
The procedure can be performed from the wrist or an upper thigh artery to introduce contrast (dye) and make X-ray pictures of the coronary arteries.
The test determines the exact nature, number and location of the blockages in the coronary arteries caused by plaque build up.
This test is a must before any meaningful discussion about treatment options can be conducted and it can be bundled together with the stent procedure.
This is an outpatient procedure, anesthesia is not necessary and discharge home in a few hours is customary.
Being totally non surgical a Balloon angioplasty is similar to performing a coronary angiogram and is the act of simply inflating a small balloon advanced through a coronary catheter into a blocked coronary artery to essentially squish the plaque out of the way. This mode of treatment is seldom used today in a stand alone fashion but is an integral part of the more sophisticated coronary stenting procedures.
Being an outpatient procedure anesthesia is not required and same day discharge home is customary.
Being totally non surgical the Coronary Stenting procedure is essentially similar in nature to a coronary angiogram and is also performed from the wrist or upper thigh.
It is the act of introducing a stent (a small very fine fenestrated metal scaffold mounted on a balloon) into a blocked coronary artery which is then expanded to move the plaque out of the way.
Almost all modern stents are medicated to diminish the chance of plaque recurrence and are called drug eluting stents (DES).
Typically being an outpatient procedure general anesthesia is not required and same day discharge is customary.
Atherectomy is a term reserved for chiseling a safe passage through coronary blockages that are hardened by calcium deposition using a small roto rooter like device or a laser.
All atherectomy procedures like the stent procedure are also non surgical and catheter based. They are usually an aide to successful and safe stenting of the blocked coronary arteries and are seldom used by themselves as stand alone procedures.
Another name for coronary stenting is PCI or percutaneous coronary intervention. A high risk PCI is a stenting procedure performed to eliminate complex and usually multiple coronary blockages especially blockages involving the left main coronary artery. Sometimes a high risk PCI is performed using a miniature cardiac assist device. Despite the complexity this is a nonsurgical same or next day discharge procedure and does not require general anesthesia.
A protected PCI or stenting procedure is a high risk PCI that has been made lower risk by use of a miniature cardiac assist device. Safe and effective use of this device nonsurgically requires a special skill set and is an integral component of what makes an advanced Physician of excellence™ (POE™). Despite its complexity this too is a totally non surgical procedure requiring no general anesthesia and next day discharge is customary.
A miniature cardiac assist device takes over the work of the heart for the duration of a high risk PCI thereby lending the procedure another layer of protection thus converting it into a “Protected PCI”.
This device is just a thicker flexible tube advanced from the leg or the upper arm to the main pumping chamber of the heart called the Left ventricle. It pumps the blood out of the Left ventricle into the Aorta which in turn carries blood to every part of the body.
The device is introduced and removed without surgery and as such does not require general anesthesia and next day discharge is customary. Safe use of this device ideally requires operators to have in depth understanding of catheter based management of peripheral arterial disease.
Peripheral arterial disease (PAD) is severe blockages of arteries other than the heart and brain. Typically PAD affects arteries carrying blood to the legs. Since most complex stenting and miniature cardiac assist device support is undertaken from the leg arteries, PAD can pose a major impediment to safe delivery of non surgical catheter based treatment of coronary blockages.
Therefore coronary operators having additional expertise in the area of non surgical PAD treatment with balloons , stents and atherectomy procedures are a cut above operators who do not possess such expertise.
This faculty becomes especially evident during safe delivery and removal of the miniature cardiac assist device without having to call in a vascular surgeon.
100% blockage of an artery is called a Chronic Total Occlusion or a CTO. Typically the territory subtended by a CTO is partially infarcted and partially protected by collaterals (natural bypasses). CTOs present specific challenges to successful treatment by catheter based approach. However over the last few years novel techniques have emerged that have surmounted the technical challenges of CTO recanalization leading to a markedly increased rate of success. Patients most likly to benefit from CTO recanalization are typically younger more active individuals with a large burden of ischemia. Asymptomatic patients with good exercise tolerance may not benefit much from CTO recanalization.
CTO recanalization as part of complete myocardial revascularization strategy is a relatively new and exciting area of research with early indications that complete revascluarization may have long term survival benefits irrespective of whether it is achieved utilizing Coronary bypass surgery or Coronary Stenting.
Physicians Par excellence™ are what make regional Centers of excellence for complex coronary stenting and in the opinion of this site these centers may not necessarily be the same centers that are known for outstanding results in coronary bypass graft and open heart surgery.
Any center that provides Physicians Par excellence™ a frictionless venue conducive to performing complex coronary stent procedures in lieu of coronary artery bypass graft surgery is deemed by this site as a center of excellence for complex coronary stenting.
The names of such institutions near you are best obtained from your matched Physician Par excellence™.
27. What is coronary bypass graft & open heart surgery?
Coronary artery bypass grafting and open heart surgery is an operation that involves:
Over the last 25 years there has been a dizzying array of studies comparing PCI vs CABG allowing in turn for varying interpretations and recommendations.
A comparison of extended long term survival
i.e. comparison of survival at 15 years or more is simply not available. However for the first time a comparison of ten year survival PCI vs CABG was recently published in JACC (Journal of American College of Cardiology.) The authors evaluated 2240 patients who underwent CABG or PCI from the year 2000 – 2006. Even with the use of the outdated first generation DES (drug eluting stent) the survival of patients who underwent PCI for Multi-vessel CAD including Left Main blockages was comparable with patients who underwent surgery.
Well over 30% of the patients in this trial were Diabetics.
Even before the introduction of Coronary stents PCI in the form of Plain Old Balloon Angioplasty demonstrated equipoise with CABG at 10 years except in diabetics. (BARI trial)
Survival at 3- 5 years has been looked at in multiple studies over at least the last 20 years.
These studies include BARI, RITA, ACME, MASS, AVERT, TIME, SYNTAX 1, SYNTAX 2, EXCEL and NOBLE amongst others.
In general the 3-5 year survival with CABG and PCI in patients with Multi-vessel CAD including Left Main Coronary artery disease is comparable except in diabetics and in patients with a high Syntax score.
In Diabetics with multi vessel CAD in general the 5 year survival with CABG is superior to PCI.
More recently FREEDOM trial has looked at 8 year survival in diabetics undergoing surgery vs PCI claiming superiority with a surgical approach.
However the results of this trial are being challenged by several investigators:
1) Speaking at the 2018 annual sessions of American heart association where findings of the FREEDOM trial were presented, experts noted that 1 million coronary revascularization procedures are performed each year, with 35% done in patients with diabetes. It was also noted that despite the randomized nature of the trial, bias was possibly introduced with just under half of patients followed and that the follow up study is also likely underpowered.
2) In an editorial accompanying the study published in the Journal of American College of Cardiology, several other experts questioned the reliability of the mortality benefit in FREEDOM trial.
They point out that just 16 more deaths in the CABG arm would have rendered the between-group difference statistically nonsignificant.
3) Additionally, they suggest that data from more recent clinical trials and registries has shown even more improved results with new -generation drug -eluting stents.
4) Interestingly, a recent individual patient data pooled analysis of 11 RCTs (randomized controlled trials) published in JACC in 2018 demonstrates a significantly greater risk of stroke after CABG especially in patients with diabetes and Multi-vessel CAD.
The five year mortality was significantly higher for patients experiencing a stroke within 30 days after revascularization.
The 5 year outcomes can also vary depending upon complexity of CAD as determined by the SYNTAX score; A very high Syntax score favors surgery.
CABG may offer better 5 year survival rates in diabetics with triple vessel CAD but in most studies comparing CABG Vs PCI for Multi-vessel CAD there was an initial higher peri-operative mortality and stroke rate with CABG. There was also a much higher rate of arrhythmias including atrial fibrillation with surgery.
Both major stroke and cardiac arrhythmias like atrial fibrillation translate into major long term debility and the accompanying lifestyle issues.
Chest sawed open to access the heart.
The entire procedure is performed by gaining access to the heart using a small catheter advanced through an artery from the wrist or the upper thigh.
In a nutshell if all available scientific data comparing PCI vs CABG is taken into account it would appear that:
Complete revascularization entails addressing all blockages including Chronic Total Occlusion (CTOs). In the past complete myocardial revascularization typically required CABG and OHS. More recently with advances in CTO revascularization techniques the same is being achieved without open heart surgery using the stent procedure.
There is data suggesting there maybe survival benefit that accrues from complete revascularization versus incomplete revascularization whether it is achieved non surgically by the coronary stent procedure or by CABG/OHS.
Reference # 8 (TCT-397 10-year outcome after complete versus incomplete revascularization of patients with multivessel coronary artery disease)
Having stated the above, attempts at complete revascularization even by CABG is a complex issue not entirely without its own limitations.
Reference # 9 (Complete myocardial revascularization: Between myth and reality)
Thus it is not unreasonable for an operator to tailor therapy to the particular patient in question and to balance the risk benefit ratio of complete vs incomplete revascularization.
It maybe prudent in certain target populations like older, sicker and less active patients to settle for near complete but functionally adequate revascularization.
Off pump coronary artery bypass (OPCAB) refers to bypass surgery performed without stopping the heart and without going on the heart lung machine. It can be performed using the conventional chest sawed open approach or it can be performed robotically.
MIDCAB (minimally invasive direct coronary artery bypass) employs a smaller incision and a robot while TECAB (totally endoscopic coronary artery bypass) is performed totally robotically. Whereas the surgical trauma of these minimally invasive off pump techniques is less than the conventional approach there lingers controversy and debate in the surgical literature about long term patency of the bypass grafts.
Although appropriate use criteria (AUC) have been issued from time to time, the actual guidelines of the American College of Cardiology (ACC) for myocardial revascularization in stable ischemic heart disease were last published in 2011 with a partial update in 2014.
According to these guidelines, when it comes to Left Main disease and multivessel coronary artery disease CABG is listed as a Class I indication for Myocardial Revascularization while PCI/Stenting is listed as a Class II indication.
However, that was before the popular use of miniature cardiac assist devices that have revolutionized high risk PCI.
Moreover the stents used in the studies these guidelines were based upon were mostly the first generation coronary drug eluting stents; the newer stents have a much improved performance profile.
Heart team approach as currently encouraged by most hospitals boils down to obtaining the approval of the cardiac surgeon before an interventional cardiologist may embark upon a Complex PCI/Stent procedure in lieu of open heart surgery.
In the past, one of the reasons such an approach was deemed necessary was because there existed a small but finite chance that emergency open heart surgery could become necessary during the stenting procedure.
However, with the rapid evolution of PCI/Coronary stenting as a safe and effective non surgical technique for myocardial revascularization the need for surgical backup has markedly diminished; in other words it is uncommon that a patient undergoing a protected PCI will end up requiring emergency open heart surgery.
Interestingly, there is an evolving role of emergency Coronary stenting/PCI in the immediate post CABG/OHS patient to prevent serious complications arising from early failure of bypass grafts as recently reported in the Journal of American College of cardiology.
As such, based on supporting scientific data establishing equipoise between surgery and PCI for the treatment of most non diabetic patients with complex coronary artery disease, it is the opinion of this site that the Heart Team approach concept as currently practiced needs an update.
NOCOBYE™ believes that in all intellectual honestly it may now be time for a “BALANCED HEART TEAM APPROACH”.
In other words any patient advised CABG/Open heart surgery should at least also be educated about and offered the relatively comparable nonsurgical catheter based treatment options, namely coronary stenting/PCI.