Cardiovascular diseases are – according to the (World Health Organization (WHO) – the number one cause of death globally. Myocardial infarction (heart attack) is the most prominent under the Cardiovascular diseases. In Switzerland alone, the risk to develop a coronary heart disease during life time is around 25% for men and 18% for women. Most cardiovascular diseases can be prevented by addressing behavioral risk factors, the understanding of these risk factors, their mechanisms and impact on the cardiovascular system. In this context our course aims to approach the complex field of myocardial infarction in two respects: medical education and awareness of a broader audience.
Outcome after Acute Coronary Syndromes
Loading...
From the course by University of Zurich
Myocardial Infarction
26 ratings
From the lesson
Acute Coronary Syndrome: Follow up and Rehabilitation
Module four illustrates the methods employed to improve cardiac rehabilitation. Moreover, this module focuses on the secondary prevention to avoid the risk of myocardial infarction. This involves the analysis of external and biological factors which can cause cardiac diseases and explains the mechanisms needed to change bad behavioral patterns. There are several factors in life which can be easily altered to improve the personal wellbeing and those are discussed in this section.
Meet the Instructors
Prof. Thomas F. LüscherMD, FRCP, FESC, FACC
Professor and Director of the Cardiology Department, University Heart Center Zurich, University Hospital Zurich
I'm Tom Luscher.
I'm Professor of Cardiology at the University and the University Hospital in Zurich,
Switzerland.
We're talking about myocardial infarction in our module.
And today we focus on the outcome after an acute coronary syndrome,
which is the overall expression for
different forms of acute myocardial infarction.
Now, when a patient comes to the hospital,
he goes to the emergency room, then to a chest pain unit, if available.
And eventually in the catheterization laboratory and in the coronary care unit.
So, this is what happens within the hospital, with the flow of the patient.
Now, what is the outcome of a patient entering a hospital?
Well, first of all, he will get all the drugs to make sure
that the result, achieved by percutaneous coronary intervention, will also sustain.
And that is aspirin, P2Y12-Inhibitor, that also is a platelet inhibitor,
a Statin to reduce cholesterol, an ACE-Inhibitor to prevent
any enlargement or remodeling of the left ventricle after myocardial infarction.
And some actually need other drugs as well.
Those with arrhythmias, beta blockers.
Those with high blood pressure, antihypertensives.
The diabetics, of course, need anti-diabetics.
Possibly insulin and other drugs as well.
What is the in-hospital mortality today?
When Eisenhower had his heart attack in 1955, it was more than 50%.
Today, overall, about 1 in 20 patients is dying.
Overall, of course the mortality rate, as you can see in ACS total, is the highest.
If patients with shock are excluded and the only patients that come with
normal hemodynamics, are considered, mortality is much, much reduced.
Patients who didn't require any cardio pulmonary resuscitation,
have even a better outcome.
And if you have no CPR and no shock, no major complications,
the event rate is extremely low and only 1 in 20 patients is dying.
So, a simple ACS, like an unstable Angina, has an even lower mortality.
So, in summary, we can say that the mortality in acute coronary syndromes
depends a lot on the initial presentation.
Whether the patient had experienced sudden death, was resuscitated,
whether he has pump failure due to a large infarction and
of course, the quality of CPR and those who drop dead outside the hospital.
Now why do patients die if they're in the hospital and
have an acute myocardial infarction?
Interestingly, actually almost a third dies because of hypoxic brain damage.
They have such a strong damage of the brain that they don't wake up and
die eventually of aspiration pneumonia.
Patients with cardiogenic shock, Obviously, the heart is not able to
sustain the cardiovascular system. It's a mortality cause.
Palliative situations, when we decide not to go further in a particular
patient because of comorbidities.
Some die of stroke.
Ventricular rupture is getting rarer these days.
Bleeding can be a cause, but
Fortunately, has become quite rare during modern management.
Now here you see the in-hospital clinical events that occur in patients with STEMI,
with non-STEMI, or those with unstable angina,
abbreviated UA, in this very instance.
And you can see that many patients have reinterventions.
They have further infarctions, and it depends really on the presentation.
Patients with unstable angina, most frequently, eventually have
an intervention, while the other two groups obviously have it already at
the very beginning and they die of all the causes that I just indicated.
But many of them also have additional cardiac events.
One of the events that is Important, is bleeding.
And you can see the incidents of bleeding after PCI increases over many months.
And the reason is, that these patients receive antithrombotic
drugs such as aspirin and P2Y12 inhibitors.
Such as clopidogrel, prasugrel or ticagrelor.
And the most common site of bleeding is the groin and
Therefore, many centers now use the radial approach to treat patients
with acute coronary syndromes to avoid bleeding.
Now, once patients are out of the hospital,
they commonly go to cardiac rehabilitation.
Either on an outpatient setting or in a rehabilitation clinic.
And after three to six weeks, they go back home.
And after a while they usually resume work and are back at work.
So, what happens once they are back in normal life?
MACE or Major Adverse Cardiac Events at follow up are very common and one of
the most dangerous one is stent thrombosis, which occurs in 1 in 100 patients.
As shown here, where you see at the arrow, there is a fine stent and
it's completely occluded by thrombosis,
that occludes the left interior coronary artery, where you only see the stump.
There are many causes of stent thrombosis:
One is, of course, the patient itself, like diabetics have more stent thrombosis.
Patients with acute coronary syndromes have more stent thrombosis.
The stent itself, by a resorbable stents or
scaffolds have more stent thrombosis than the classical perimetal stents.
And of course, also the procedure itself, is important.
Here you see an optical coherence tomography of a stent thrombosis.
On the top left corner, you see a bioabsorble stent.
And you can appreciate the thrombosis formation at the site of the vessel
wall that eventually led to occlusion.
And now, with the wire being pushed through the thrombus,
you can see the wire and the OCT catheter.
The sizing of the stent is important.
On the right top panel you can see that the stent has been too small and
that leads to stent thrombosis.
Then the underexpansion of the stent, on the lower
right corner, is an important cause.
And after a while, after a year or
two, new plaques can form so-called neoatherosclerosis within the stent.
Thus, stenting should be preformed optimally, with the right stent size,
high pressure implantation, no bioabsorbale stents should be
used at this point in time and optimal secondary prevention is crucial.
You can see here that in large trials, the event rate after
an acute coronary syndrome is quite substantial and averages 10% at one year.
In the PLATO trial, one in ten patients had some events like infarction,
stroke, or death, or rehospitalization for heart failure.
In the PEGASUS trial, that started a couple months
after an acute coronary syndrome, the event rate was a bit lower.
But you can see that up to three years, there is a continuous increase in events,
demonstrating that patients are not cured after effective modern
guideline-based treatment of an acute coronary syndrome, but
continue to have events that have to be managed.
Thus, after an acute coronary syndrome,
the survivors of the event are at continued cardiovascular risk for
re-infarction, stent thrombosis, stroke, heart failure and death.
Some groups are particularly prone to major cardiovascular events,
such as the diabetics.
You see here in the PEGASUS trial, those with and without diabetes.
Those without diabetes, in the dotted lines,
have a much lower event rate than those who have diabetes.
No matter whether they have pidogrel or ticagrelor as antithrombotic treatment.
Also patients with renal failure have a much higher event rate
after an acute coronary syndrome, as you can see in the top two lines
that refer to those treated with ticagrelor or
clopidogrel respectively, compared to those who have no renal failure.
Where the two drugs have more or less the same event rate.
So, the question is, if thrombosis, infarction and
stroke are an important cause of events after an acute myocardial infarction.
How long should we use dual antiplatelet therapy or DAPT?
That is aspirin plus a P2Y12-Inhibitor.
Well, we could say forever, because we want to avoid stent thrombosis, or
a new occlusion, a new infarction.
But of course, dual antiplatelet therapy increases the risk of bleeding,
as shown here in the stomach,
with a severe arterial bleeding that can also threaten the life of a patient.
So, we have to consider both, the ischemic risk of a patient and the bleeding risk.
Bleeding risk increases with age, when they take non-steroidal
anti-inflammatory drops, or have a history of gastrointestinal bleeding.
The ischemic risk is the higher the more vessels are involved.
Three vessel coronary artery disease has a higher ischemic risk than a single
coronary artery disease.
And this has to be balanced by an experienced physician.
But, what is important in the next graph, is that the events are as common
in the stented region, as they are in regions of the coronary circulation
outside the occlusion, where no stent has been placed.
And this demonstrates clearly that atherosclerosis is a progressive disease
in nature.
And therefore, new plaque formation has to be avoided under all circumstances.
So, the atherosclerosis process is progressive in nature and
thus, patients with an ACS continue to develop new plaques
that are causing further mace such as infarction and death.
And besides statins that are common practice today and
lower cholesterol substantially, in those that do not reach appropriate
target levels of cholesterol or LDL-cholesterol in particular,
such as 1.8 millimoles per liter, they should be considered for PCSK9 Inhibition.
PCSK9 is a protein that is released from hepatitides and
degrades LDL receptors, leading to higher LDL levels.
Now, if you give a PCSK9 inhibitor to a patient such as
show in this Glagov trial, you can reduce LDL-cholesterol substantially further.
The stroke has to be applied subcutaneously by injection, twice weekly.
And what's important in this Glagov trial, you can see here is the reduction
in plaque formation, as assessed by intravascular ultra sound.
And you can see, once you reach a level of LDL-cholesterol of 1.4 or lower,
there is actually a regression, that means that the plaque becomes smaller.
It's below the zero line on the slide and
that this provides regression of atherosclerosis and
therefore, further events should be avoided under these conditions.
And indeed, a recent large trial, with more than 20,000 patients with
a PCSK9 Inhibitor,
have a look up in this instance, has shown in the four years trial, that the event
rate is further reduced when we lower cholesterol further by a couple of percentages.
So, in summary,
we can say that ACS remains a condition with high morbidity and mortality.
Optimal guideline-based management is crucial.
In spite of optimal management, in-hospital mortality remains at 5% overall,
particularly in those that have undergone cardiopulmonary resuscitation or
present in cardiogenic shock.
Events continue to accumulate after ACS at the rate of 10% in
the first year and continue to accumulate further thereafter.
Thus, secondary prevention with further lowering of LDL-cholesterol.
But also normalization of blood pressure and plasma glucose,
among others, have to be improved to the benefit of our patients.
I thank you for your attention.
Explore our Catalog
Join for free and get personalized recommendations, updates and offers.
Coursera provides universal access to the world’s best education,
partnering with top universities and organizations to offer courses online.
© 2018 Coursera Inc. All rights reserved.
