I know that this is a pretty broad question. Therefore, I would like to start by setting my boundaries. First, I would like to take the question from a big picture perspective because that approach helps to understand most of the recommended preventive efforts and treatments. Second, I want to be clear about the meaning of coronary artery disease. Three arteries ring the top of the heart like a crown, giving them the designation coronary, from corona. Any illness that affects these arteries is reasonably called coronary artery disease. But, let’s not ignore the elephant in the room. One disease will affect ⅓ to ½ of us in our lifetime, loves the arteries of the heart and, most importantly, causes heart attacks. The disease is atherosclerosis, a corrosive scarring of the arteries, and almost any time someone says coronary artery disease, that is what they mean.
Atherosclerosis is a disease in the sense that it causes illness and suffering. However, the source of the problem is, to a great extent, in how we are designed to process and store what we eat and maintain our arteries. As most of us make the morning navigation to work, we mull over thoughts of success that center on peace, serenity and financial security. Mother nature sees things from a different perspective than you and I. From the biological perspective, success is navigating our hostile world long enough to reproduce. That is the target of our design and the goal of the genes that help to make us who and what we are. The genes that have made us such a rousing success developed under much different circumstances than we face today. In a hostile world, with scarcely enough to eat, full of predators, large enough to eat us and too small to be seen, those genes carried primitive people through their twenties and thirties, long enough to be fruitful and multiply.
Generally speaking, people are made to survive frequent hardship, long walks looking for food and long times without it. Weather was to be endured, abundance enjoyed and water kept in convenient reach. These were the challenges to be overcome for success and we are well equipped. We have long legs, can eat almost anything and store energy with great efficiency. However, our most important advantage is not physical.
We have the ability to learn, individually and collectively. We can make tools, build houses and, most importantly, write everything down. This advantage brings plentiful food, treatment for infections and longer lives. Under these conditions, our biological design for self-preservation misfires in many forms of cardiovascular disease such as high blood pressure and coronary artery disease. In essence, our heart and arteries are designed to maintain themselves under a set of difficult conditions and last a lifetime. With all of the success born of cumulative learning, we have moved outside of the conditions that shaped us and changed the duration of a lifetime.
Modern society lets us survive long enough to suffer from atherosclerosis and modern technology lets us see it. At any given time, more than 15 million people in the US have symptomatic atherosclerosis. It affects the heart most famously, but can also cause stroke, loss of limb, damaged kidneys and dysfunctional intestines. Of the 1 million people who will have a heart attack this year, almost all are over 40, an age seen by a lucky few of our primitive ancestors.
Atherosclerosis is very much affected by the body’s energy metabolism. It strolls along happily with obesity and inactivity. Obese and inactive adolescent children may already have arteries that misbehave. Their arteries may not be diseased at that young age, but measurable misbehavior is believed to be one of the first steps toward disease. By the age of thirty, some people may have an abnormal appearance of the arteries on an angiogram. Most heart attacks occur much later in life, meaning that this disease starts early and may be present for a very long time before it starts to cause problems.
Atherosclerosis can remain silent for so long because it is alive. Unlike the debris in a clogged drainpipe, atherosclerosis is in constant negotiation with the walls of arteries, forcing them to adapt to its presence. Baudelaire said that the “finest trick of the devil is to persuade you that he does not exist”. Atherosclerosis has mastered this trick as well. Arteries accommodate disease in their walls by enlarging so that blood flows freely. Each step that may help atherosclerosis along does not exact immediate restitution, but lays claim much later, when the arteries can no longer accommodate. Fortunately for us, atherosclerosis is the rarest of all biological cats. By addressing the root cause of disease, we can put it back in the bag… at least part way.
The processes, actions and events leading up to a heart attack are partly determined by our inborn programming and partly by the life that we lead. The almost universal coexistence of plentiful food and heart attack lends credence to the misunderstanding that atherosclerosis is simply a penalty for each moment spent enjoying a cup of coffee and a donut. The truth is a bit more complicated. We each live within a design that dictates how we store energy from food, distribute salt and water, fight infection and function physically. Our design was shaped under different conditions from those that we presently encounter. As a result, many of us may encounter difficulty as we age because the lifestyle that has become normal combines with our design to steer a course that will end in decay of our arteries. For most of us, the inherited parts of our design that predispose to atherosclerosis and heart attack are not genetic errors. They are built-in safeguards for times of need. In a different setting, of environment or of food availability, these tendencies may be advantages for survival. In times of plenty, they are not.
Preventing or treating atherosclerosis requires realignment of modern lifestyle with our design. Alignment with design refers to all of us in a general sense as well as each of us specifically. We do not all share the same inheritance. Therefore, the prescription to align with our design will vary from person to person.
More on coronary artery disease can be found in the educational booklets for CAD and Heart Attack here.
Aspirin prevents heart attacks. I know that you may find this jaw-dropping, but it’s true. On the other hand, you may have seen some recent information that was published in the New England Journal of Medicine that casts doubt on the value of aspirin. Before rushing to a conclusion, let me give you a bit of background. The “new” information about aspirin isn’t really new. However, it is very useful to stimulate discussion about the proper use of this amazing, and sometimes dangerous, drug.
What does aspirin actually do?
Let’s begin with the fact that aspirin is not really a treatment for the disease that corrodes your arteries. It is a last gasp to keep an artery from closing after the disease has gotten very, very bad. What happens is that the body has to send fat around to all of its parts for use as energy and some other things. The packets that carry the fat around get stuck in the artery walls and constantly irritate, like a stone in your shoe. The body’s response to these irritating little packets corrodes the arteries. Too many packets floating about or arteries where the packets can easily get stuck are the cause of the disease. After the artery has been back and forth trying to rid itself of these fat packets for quite some time, corrosion sets in and eventually a blood clot can form. The blood clot is the final straw to close the artery. Aspirin keeps blood clots from forming properly. That is not a genuine fix. It is not really treating the underlying problem, but when facing the danger of a heart attack, it is better than nothing.
“More doctors smoke Camels than any other cigarette”
In 1949, this was a real ad and it wasn’t the only one of its kind. No one knew what caused coronary artery disease. However, it was accepted that the final event of coronary artery disease, a heart attack, was due to a blood clot that formed in the arteries that feed the heart. At the time, most people with symptoms of coronary artery disease would suffer a heart attack within five years after symptoms began. Most people died of their disease after about ten years. The heart attacks and the deaths were clearly tied to abnormal blood clotting, but there was nothing that anyone could do about it.
Under these circumstances, a California physician named Craven took notice of several small articles about bleeding problems after surgery in people who used aspirin. He reasoned that, if an innocuous drug like aspirin made surgical wounds bleed, it would also prevent blood clots from forming on their own in the coronary arteries. His ideas did not gain much traction. He experimented with his own patients and felt that his efforts were successful. He offered the evidence from his observations. However, it would take another 20 years for aspirin’s effects upon blood clotting to be put to regular use.
By the 1970’s, the treatment of coronary artery disease and heart attack remained very limited. Dr. Craven’s ideas had become mainstream and aspirin was tested for the treatment of people with symptoms threatening a heart attack. It was wildly successful and represented a major breakthrough. Aspirin did not help resolve symptoms, but it appeared to keep them from progressing to the point of a full blown heart attack. It also saved lives. However, outside of the people with symptoms of a threatened heart attack, the value of aspirin was not quite certain at first. Survivors of heart attack who continued to use aspirin for long periods of time did not seem to really gain anything. As a result, no one knew if the average person who just wanted to avoid a heart attack should use aspirin.
The question was put to the test in the Physicians’ Health Study that began in 1982. This was an enormous study of mostly men who presumably followed reasonable health habits (we physicians are really only marginally better than everyone else) and would be compliant with a study protocol (see earlier comment). Aspirin worked. In fact, it worked very well. However, the qualifying statement is to remember when this study was done. The basic forces causing coronary artery disease were not really being treated effectively.
So what has happened?
In the New England Journal of Medicine for October 18, 2018 (https://www.nejm.org/doi/full/10.1056/NEJMoa1800722, https://www.nejm.org/doi/full/10.1056/NEJMoa1805819, https://www.nejm.org/doi/full/10.1056/NEJMoa1803955, https://www.nejm.org/doi/full/10.1056/NEJMoa1804988), several large-scale studies took aspirin to task and strongly suggested that we rethink its use to prevent heart attack in people who are otherwise reasonably healthy. In older people (>65-70) or people with diabetes, people that often consider themselves at risk of suffering a heart attack, aspirin was a bust. Aspirin may have prevented some problems that we know to be the result of blood clots. However, aspirin caused as many other problems that we know to be the result of bleeding that it harmed as many people as it helped. In short, if you are reasonably healthy and want to do something to lower your risk of death or disability due to heart attack, aspirin is not your best option, or even a good one.
How is this possible? How could something so cut and dried look so different now. Well, between then and now, we learned and got better tools to prevent heart attack. In 1990 effective cholesterol-lowering medicines became available. By 1997, cholesterol could be lowered very effectively and the treatment of diabetes became more sophisticated. Ask anyone on the street their cholesterol number and almost ½ will know the answer. Many of them will already be taking steps to address it. In fact, in the studies addressing aspirin’s potential benefit for reasonably healthy people, roughly ⅓ were taking cholesterol lowering medication. Almost ¾ of the diabetics were on such medicine. And not many people were smokers.
If the disease that corrodes arteries is prevented by not smoking, cholesterol lowering, diet and effective treatment of diabetes, aspirin may have less to offer than it did in the past.
Does this mean aspirin doesn’t really work?
The answer to this question is a resounding NO. Aspirin is a tool that, applied properly, performs admirably. The message of these new studies addresses people who do NOT have known disease of the arteries. That means that someone who already had coronary artery disease, a prior heart attack or stroke, or peripheral arterial disease was not asked to participate. Only people who were interested in preventing their first episode of heart disease were studied. There is no question that aspirin and medicines like it remain an important part of the protective medical regimen for anyone with definite arterial disease. On the other hand, if you are among the worried well and want to avoid heart attack, the right answer is diet, exercise, not smoking and a periodic meeting with your doctor to evaluate your cholesterol and blood sugar.
Stress Cardiomyopathy, also known as Takotsubo Syndrome, and its related syndromes are most likely a toxic injury to the heart, resulting from a brief but profound, high intensity exposure to adrenalin or noradrenalin. These events have been most closely associated with circumstances, illness and injury that would be expected to activate the body’s self-preservation system. In lesser degrees, fear, anger and anxiety can create symptoms that mimic heart attack, without EKG change, blood evidence of injury or abnormality on any type of testing. In the past, and still unfortunately in some forums, these events have been referred to as panic attacks. This misnomer promotes the misunderstanding that this sometimes crippling disorder is in some way under direct conscious control.
Considered in full, our protective behavior is layered from the very basic pain response to the intricacies of imagination and anticipation. At the very basic level is sudden withdrawal from pain. No thoughts are required to guide this action, though they may follow in the awareness of pain. Far more complicated is the subtle discomfort of fear, driven by nothing more that thought. Fear accompanied by visceral symptoms, like sweating, breathlessness and nausea may be triggered by nothing more than anticipation of an uncomfortable situation.
A sensation perceived as threat is processed in an area of the brain called the amygdala. It is the point of communication between rapid, unconscious response and the thinking brain. As a rapid response to pain or threat is carried out, the amygdala invokes base emotional responses to color conscious thought.
Some of this response is probably hardwired. For example, in all but the most thoroughly conditioned, sudden changes in environment, a blinding flash or the peal of thunder provoke a startle. Fear is triggered. A physical response begins. It may be quickly aborted, but it is very difficult to prevent initiation by a typical trigger. Consider the sensation after a near miss on the freeway, when only a quick twist of the wheel avoided certain collision. The act was not truly deliberate. In its aftermath, the event is consciously replayed, the after effects are recognized as adrenalin’s effect wanes and fear is acknowledged.
Individuals with repeated exposure to unpleasant surroundings may become inured to flashing lights and loud sounds so that startle does not occur. Therefore, the process of the, almost reflex, emotional response can bend to conditioning. It is conditioning or modification of the process of a different sort that can become a health problem. Traumatic events carry memories of associated sights, sounds and smells. Conscious replay of events may attach seemingly innocuous sensory input to a perceived life-threatening or traumatic event so that the short path to emotional response is triggered inappropriately, even unconsciously. In addition, the pathway to emotional response may activate with no outward cause. No prior conditioning, no bad experience, in fact nothing at all is needed for this response mechanism to take on a life of its own. When this occurs, bouts of rapid heart rate, hunger for air, sweating, blood pressure elevation and chest discomfort can develop, seemingly out of thin air.
For many people, the symptoms of the fear/anxiety response become like a seizure disorder. They may be completely unpredictable, occurring at home, in public, alone or with family. They may occur while awake or awake someone from sleep. To the affected, the sensations are indistinguishable from severe illness with the threat of death. The conscious mind is indeed seized by the more dominant emotional center producing events that have escaped control. The discomfort is real. The changes in the body’s physiology may be so profound that, without testing, it can be impossible to distinguish such an event from an ongoing heart attack.
In 1871, Dr. Jacob Da Costa, a physician active in the American Civil War, recorded the symptoms of hundreds of soldiers who were crippled by bouts of breathlessness, palpitations, fatigue, sweats, nervousness, and dizziness. Their illness clearly arose from war experience, yet no measurable abnormality could be found. He described the appearance of the suffering veterans in the throes of these events, and afterwards, as that of someone engaged in severe or exhausting effort. Da Costa’s observations were quickly dismissed and forgotten. Many years later, the symptoms, findings, and experience collected by dedicated, scientific study would reawaken interest in this phenomenon. It then received the name "Da Costa’s syndrome". Unfortunately, the concept still did not find firm footing in the medical lexicon. Names like neurasthenia, nervous exhaustion, shell shock, soldier’s heart, panic and anxiety disorder were bandied about. The disorder Da Costa described is an abnormality in nervous function that can be primary or triggered by external stressors. It is genuine, organic, and treatable. Therefore, patients are best served if we use the name DaCosta’s Syndrome in preference to the pejorative, Panic Attack.
The sensations and outward appearance of the affected individual very closely simulate a heart attack. They may occur in response to specific sights, sounds, smells, or situations. When part of another disorder, such as Post-Traumatic Stress Disorder, the triggers may be very specific. However, when the disorder is primary, there may be no trigger. Episodes occur at random and may wake some people from sleep. Anyone may be affected. I have taken care of firefighters who can face a burning building, yet are still troubled by these episodes with no recognized trigger. Unfortunately, there is no test to be certain of their presence. All other sources of discomfort must be ruled out before settling upon DaCosta’s syndrome as the cause of symptoms. On the other hand, there are effective treatments. Several medicines, particularly those affecting serotonin use in the brain, are useful and not habit-forming. Behavioral therapy may also be effective and eventually allow withdrawal of medicines. All should be coordinated with the help of a physician.
There are many different causes of heart failure with a normal ejection fraction The two most common, a lifetime without any physical conditioning and the long-term effects of high blood pressure, have no specific treatment beyond blood pressure control, physical rehabilitation and the judicious use of diuretics (fluid medicine). The usual armamentarium of drugs to assist the heart’s efficiency does little to alter the course of illness, making this form of heart failure most vexing. Recently, an illness, once thought to be a terribly rare cause of heart failure with normal ejection fraction, has proved to be awfully common and appears to be treatable.
The illness, called Amyloidosis, is characterized by deposition or silting of unused protein in between the cells of various organs. Proteins are normally made, used and recycled. When that process is disturbed, unrecycled protein may accumulate and deposit in between cells. In the heart, the protein leaves little room for cells to stretch out and the walls of the heart become thick and stiff. Blood pressure in the veins of the body and lungs must stay high to force blood inside of the heart. The result is swelling in the ankles and trouble breathing or a heart that just pumps less blood.
The first recognized type of Amyloid was due to cast off and unused antibody from an immune system that was, for various reasons, in the habit of overproducing. This type of amyloidosis is relentlessly progressive and difficult to treat. Fortunately, it is uncommon and amyloid heart disease was felt to be rather rare. In fact, more than one type of discarded protein can cause amyloidosis and amyloid heart disease is not so rare at all.
Transthyretin is a protein similar to the ubiquitous albumin. Its function is mainly to carry other substances, like thyroid hormone and Vitamin A, on their travels through blood. Transporting thyroid hormone and retinoic acid (Vitamin A) gave rise to the name. Abnormal transthyretin or its abnormal metabolism may result in accumulation, mostly in the heart or peripheral nerves. This form of amyloidosis can vary in severity. Unlike its more malignant cousin, it may be quite subtle. More importantly, it is far more common and may be responsible for as much as 5% of heart failure with normal ejection fraction. Since heart failure with a normal ejection fraction represents ½ of the people with heart failure and the prevalence of heart failure is rapidly climbing, that 5% represents a lot of people.
Part of the problem with discovering amyloidosis is that, in years past, the heart had to be biopsied to make a diagnosis. Fortunately, technology now allows the proteins that deposit in the heart to be seen or suspected without a biopsy. The first observation that raises suspicion is abnormal thickening of the heart wall seen on an echocardiogram. In and of itself, a thick heart wall is weak evidence for a diagnosis of amyloidosis. About ½ of all people with heart failure and a normal ejection fraction, have thick walls. However, about 10% of people with heart failure, normal ejection fraction and thick walls may have amyloid. (1)
Why does this matter?
First, testing to detect amyloidosis without necessarily requiring a biopsy of the heart is available. Images from an MRI can reveal evidence of abnormal protein in the heart, if the problem is severe. Recently, a technique called T1 mapping, which is more sophisticated than just a picture, has been developed. T1 mapping may be able to detect a problem very early, perhaps even before symptoms become severe. In addition, the substance used to perform a nuclear medicine bone scan also loves the proteins stuck in between heart cells. A bone scan is a simple and easy test to perform. In essence, if the heart muscle appears thickened, a nuclear bone scan that shows the heart is good evidence that amyloidosis may be present. Both tests may make detection of this cause of heart failure possible at much earlier stages, where treatment may actually be able to reverse the process to some degree.
Not only has detection been made easier, but also Transthyretin-related Amyloidosis may now be treatable. Tafamidis is a drug that locks on to transthyretin so that it is processed more slowly, allowing it to be processed properly. In a recently reported test of the drug, Two hundred sixty-four people with proven Transthyretin amyloidosis of the heart were treated and followed for 2.5 years. Tafamidis treated people enjoyed a substantial reduction in mortality, compared to 177 of their peers treated with placebo.(2) Importantly, the observations made in the trial suggest that earlier diagnosis and treatment have greater effect.
The success of Tafamidis in treating this form of cardiac amyloidosis will be a sea change in the approach to people troubled by heart failure with normal ejection fraction. If the success of Tafamidis is confirmed, a “bone scan” may become a commonly performed test of the heart.
1. Castaño A, Bokhari S, Maurer MS. Unveiling wild-type transthyretin cardiac amyloidosis as a significant and potentially modifiable cause of heart failure with preserved ejection fraction. European Heart Journal. 2015;36(38):2595-7.
2. Maurer MS, Schwartz JH, Gundapaneni B, Elliott PM, Merlini G, Waddington-Cruz M, et al. Tafamidis Treatment for Patients with Transthyretin Amyloid Cardiomyopathy. New England Journal of Medicine. 2018. 10.1056/NEJMoa1805689
Heart failure is a general term for a group of symptoms including fatigue, swelling and difficulty breathing. Each of these symptoms may have any number of causes. When evidence points to the heart as a root cause, the constellation is known as heart failure. The heart’s failure is its inability to circulate enough blood to support normal daily activities without relying upon help from various sources within the body. Its inability to perform is the source of fatigue and its calls for help produces many of the other symptoms.
Heart failure as a diagnosis is about as specific as headache. Without a genuine reason for the heart’s failure, no speculation can be offered as to its repair. The first step toward a more specific diagnosis classifies heart failure using the most readily available measurement of the heart’s function, the ejection fraction (EF). The fraction of blood leaving the main pumping chamber (left ventricle) during each heartbeat is called the ejection fraction. Heart muscle dysfunction causing heart failure is broken down into two large categories, heart failure with an ejection fraction below normal, suggesting weakened or disadvantaged muscle, and heart failure with the ejection fraction preserved.
Of course, the heart may be inefficient because the heartbeat is mistimed or because of a broken part, like a heart valve. In these instances, heart failure is mentioned secondarily because the diagnosis is apparent in the arrhythmia or the broken part. When the muscle is the source of dysfunction, the classification scheme using EF helps to orient physicians and caregivers to the tests that may find a cause and the treatments that may be most effective.
Historically, heart muscle was viewed in a very simple fashion, like all muscle, as a tissue that shortens on command. Any failure of the muscle must be apparent in a change in its ability to shorten. As a result, heart failure was under recognized. Blood tests and a number of other techniques have improved capacity to recognize when symptoms like shortness of breath are coming from the heart. Therefore, an increasing number of people are being told that their breathlessness is coming from the heart even though the “strength,” as judged by the ejection fraction, appears to be “normal”. A muscle may function poorly if it is weak, if it cannot relax, or if the support structure that houses muscle cells functions improperly. We now know that almost ½ of people with symptoms believed to be heart failure have a preserved ejection fraction.
This entity, often referred to with the awful abbreviation HFpEF, is very real, difficult for many of us to understand and equally difficult to treat. Fortunately, as understanding improves, the ability to recognize measurable abnormalities that correspond to symptoms is improving, for example using exercise testing with concurrent Doppler echocardiography to estimate blood pressures in different parts of the circulation.
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