Video Transcript:
Researcher Varun Kumar, M.D. discusses Abstract 17488. He is an internist at Mount Sinai
Hospital in Chicago.
“In an urban setting, we often see many patients, many cocaine abusers, who's present to the
hospital complaining of chest pain. They may even undergo coronary angiogram and on the
angiogram many may even see that the coronaries are normal, but that's not the end of it.
There's more to this normal appearing angiogram. The smaller vessels more distal to the
coronaries, the big oxys. These smaller vessels actually perfuse the muscles of the heart, which
we call myocardium and this is at the tissue level so if there is any defect or any disease even in
these small vessels it carries just as bad or high mortality risk as having entered the main oxy
closed. Even this as a background, we conducted our study to see the effect of cocaine on the
microvasculature of the coronaries.
In our study we had 775 cocaine abusers who at Montana hospital had the coronary angiogram.
This was between 2005 and 2013. Of which two patients satisfied our inclusion criteria. Which
was absence of recent MI or significant coronary artery disease or even the absence of any
vessel spasm. Basically saying that the main arteries are normal. Then we compared this group
with the control group who are non-cocaine abusers and we randomly selected two patients
who satisfied the same inclusion criteria. Then we assessed TIMI frame count and TIMI
perfusion grade. This was assessed by the angiographers who were blinded to both the groups
so they did not whether the angiogram they were looking at was of cocaine abusers or noncocaine.
TIMI perfusion grade means that the perfusion of myocardium, of the heart muscle. It is graded
between zero to three. Three being the normal and zero and one being poor perfusion or
microvascular dysfunction. In that study we observed that the number of patients was
significantly higher with poor microvascular dysfunction or TIMI perfusion grade of zero or one
among cocaine users in all three vessels. Again suggesting this microvascular dysfunction. In
addition to this we also assessed for TIMI frame count, which is the number of TIMI frames
required by that dye to reach the distal standardized landmark in each artery. So the higher the
number the slower is the flow. In that study we observed that the number of frames required
by the dye to reach the landmark in LAD and left circumflex. These are the two main arteries in
the heart on the left side. They took a longer time to reach the landmark suggesting that there
could be some distal resistance. Distal resistance pointing towards microvascular dysfunction.
This was significant in cocaine group.
Thirdly we checked for a TIMI frame count less than 14. We know that faster flow we said that
it's good, but less than 14 it has a bad prognosis actually. We call this hyperemic flow. Less than
14 there were more of patients where it significant in the cocaine group compared to the
controls in RCA. All this signifying that this significant microvascular dysfunction in cocaine
abusers. Many people know that cocaine use can cause heart attack, but suppose you go to the
hospital and they say that they found normal arteries and they say that your heart looks fine
that that's not the end of it. There could still be disease in the smaller vessels which is not easily
identifiable by the standard tests. First and foremost quit cocaine. Go for drug rehab and then
you may also need to be on some standardized treatment regime like anti-platelets, like aspirin.
Cocaine can indirectly stimulate sympathetic activity which makes your heart beat fast. If
sympathetic drive goes up then your heart beats fast, the vessels can narrow, they may go into
spasm, and you may have a heart attack. Other than that cocaine itself causes platelet
aggregation which is like forming a clot within the artery. You may have a heart attack. With the
same principle the cocaine may also cause the same formation of smaller clots or vessel spasm
in the smaller vessel distal to the main arteries causing again the heart dysfunction. You may
not instantly feel anything, but over a period of time you may have difficulty walking, you may
have shortness of breath and to prevent all this cocaine has to be stopped.
In our study we didn't actually look at as to how long or hard was the duration of the cocaine
abuse, or how many times the patient has used it, or how much they were using it. In our study
we included the patient that said that they had used cocaine. We haven't gone into the
duration and other details, but given that there a few other studies done previously which
shows even if you do cocaine once or a hundred times it doesn't matter. It can cause a heart
attack any time. Cocaine abusers even if they have normal coronaries they may still have some
dysfunction in the microvasculature. As physicians it's important to look into the
microvasculature too, so that we can decide whether these patients have to be treated with
medications beside drug rehab. Cocaine no matter what it causes heart problems, so stop using
cocaine.”
copyright American Heart Association