Friday, March 29, 2013

Symptoms in men & women during PCI ballon occlusion

The trouble with "chest pain" is that it's, well, pain. The experience is subjective, bound up in the context of prior experience, current emotional state, and comorbidities, as well as the actual nociceptive stimulus. 

Not Garfield.
Frankly, this complex topic does not get any simpler when we consider the question of whether men & women report significantly different symptoms during ACS

First off, I harbor some skepticism about whether such a significant difference exists at all. For all the talk of "men present typically, women present atypically," there isn't a great deal of evidence that women have substantially different symptoms with pancreatitis, pulmonary embolism, CVA, or even appendicitis. Why should the heart be such a radically different organ? 

Nonetheless, the latest big study on the subject suggested that the rates of "chest pain-free" MI are different between the genders: 31% of males versus 42% of females. However, this was a registry study, with all the usual limitations, and so questions remain. But what can you do? It's not like you can take a group of women, a group of men, give them both MIs, and record their symptoms...

Or can you?

"Gender Differences in Symptoms During 60-Second Balloon Occlusion of the Coronary Artery"
Well, sort of.

Japanese researchers decided to approach this issue prospectively. They enrolled 110 men and 80 women who were scheduled to have PCI for stenting of a single stenotic native coronary artery. None of these patients were having any active symptoms (let alone a STEMI) prior to undergoing PCI. They figured that since the balloon inflation required to deploy the stent causes, essentially, a transient total occlusion, it might prove to be a good model for demonstrating the different symptom expression between genders.

The men and the women were fairly well matched, with the exception that the women were, on average, older than the men. The rates of comorbidities, as well as the target vessels, were similar, however.


The duration of balloon inflation during the PCI was standardized at 60 seconds, and the patients were interviewed immediately after balloon deflation for:
"presence or absence of the following symptoms during the balloon inflation: chest pain, toothache, jaw pain, neck/throat pain, shoulder pain, upper or lower arm pain, epigastralgia, occipital pain, back pain, dyspnea, nausea, and vomiting."
The first interesting point is that not everyone had chest pain when the balloon was inflated. In fact, 38/110 men (35%) and 28/80 (35%) women had no symptoms at all.

So, the genders were evenly matched for "pain-free" coronary occlusion. What kind of symptoms did the remaining 65% of men and women have?

Surprisingly, essentially all the men and women reported having "chest pain." When asked about additional symptoms, however, women reported more of the "non-chest" symptoms than did the men, although none of the individual elements reached statistical significance.

To summarize: Men and women had the same rate of symptom-free coronary occlusion, and the same rate of chest pain. Women had more symptoms on top of that chest pain, however. The researchers concluded, nevertheless, that:
[N]on–chest pain symptoms during the 60-second balloon occlusion of the coronary artery were more common in women than in men, supporting the presence of the gender difference in myocardial ischemic symptoms.
I think we're making a mistake by focusing on a putative 11% difference in "typical" chest between genders, and should instead remind ourselves that 31% - 42% of patients with ACS do not have a typical presentation. In other words, the variation in symptoms between genders is dwarfed by the range of presentations within either gender.

Furthermore, the present study suggests that the difference in symptoms between men and women, when examined in a fairly well-controlled setting, may be trivial. These results are similar to those obtained by a Canadian group in 2011. Those researchers also employed a PCI setting to record patients' descriptions of symptoms during inflationOverall, they also found no significant difference between the genders.

Now, what do EM residents really want from the review of a new study? They want to know - Can you use the results of this study in the ED tomorrow? And the "trick answer" is that no special gender-based strategy is need or even helpful
 Just be concerned about ACS in everyone!