Monday, November 6, 2017

How can you persuade your cardiologist to take a Non-STEMI patient to the cath lab emergently?

This case was sent by Joseph Ryan (@DocJoseph08), chief resident from Corpus Christi's EM residency program.  

This middle-aged patient complained of acute chest pain and called 911.

He had the following 12-lead ECG in the ED at time zero:
There is ST depression diffusely.
This is diagnostic of ischemia.
There is a Q-wave in V2 and a possible hyperacute T-wave.
It is now clear the patient has acute coronary syndrome.
It is not clear that there is, or is not, a complete coronary occlusion.

The patient was treated with aspirin and sublingual NTG on arrival, which did not relieve his pain.

Cardiology was called but they were not interested in taking the patient to the cath lab.

First troponin I returned at 0.65 ng/mL.  This confirms myocardial infarction.

After that, another ECG was recorded one hour after the first one:
The ST depression appears a bit worse.
There is a touch of ST elevation in V2.

The patient had unrelieved pain, so again cardiology was called, but they stated that the case did not warrant emergent angiography, as it "did not meet STEMI criteria."  The resident pleaded with them to take him, but they would not.

He was given Plavix 600 mg, heparin with infusion, and a nitroglycerine infusion.  His pain continued.

2 hours later (3 hours after onset)
Now there is ST elevation in aVL, aVR, and more in V2 (but the T-wave is less hyperacute). 
The ST depression in more profound.
This is very concerning for proximal LAD occlusion.

17 minutes later
About the same

2 minutes later
About the same

6th ECG, only 4 minutes later
Increasing ST elevation in V1, V2, aVL and aVR, with worsening ST depression.

2nd Troponin I returns at 3.34 ng/mL.

At this point, the cardiologist was convinced and the patient went for PCI and had a 100% proximal LAD occlusion opened and stented, with an approximate 4 hour door to balloon time.

Here is the post PCI ECG:
Beginnings of Reperfusion T-waves in V2 and aVL.
These are identical to Wellens' waves, except that there is no R-wave in V2.

And one day later:
Evolution of T-wave inversion

Echo was performed right after cath lab and showed:
1.  Left ventricular systolic function is impaired.  Left ventricular ejection fraction is 40-45% with anteroapical akinesis. 
2.  Concentric left ventricular hypertrophy.
3.  Mild mitral insufficiency.

Peak Troponin I was over 50 (they do not quantify above that.)

Peak Troponin T was 4.50 (this correlates with a very large myocardial infarction)

Smith commentary:

Learning Points

1. The purported dichotomy between STEMI and Non STEMI is a false one.
2. Patients without ST elevation, or with ST elevation that does not meet diagnostic "criteria,"  may have total coronary occlusion and may have a lot of myocardium at risk, which may infarct without immediate treatment.  This patient had a very large anterior infarction but never, even after 3.5 hours, was there ST elevation that met diagnostic "criteria."
3. Both the American Heart Association/American College of Cardiology guidelines (1) and the European Society of Cardiology Guidelines (2) recommend less than 2 hour intervention on patients with refractory angina from ACS.  I have quoted those documents below.

Also: if you think that this represents Left Main occlusion, you are incorrect.  Read this post, which explains all: STE in aVR, with diffuse ST depression, does not represent left main occlusion 

Anecdotally, by my conversations and emails with people all over the world, this recommendation appears to be ignored by many cardiologists/interventionalists.  Why is it ignored?  One reason, I believe, is a misunderstanding of the results of randomized trials of emergent vs. delayed, angiography and PCI for NonSTEMI.  It is erroneously believed that these trials were negative.  However, patients with refractory pain were excluded from these trials.  In the largest such study, the TIMACS trial in NEJM (3), they found no difference between "immediate" and "delayed" angiography and PCI except for in patients with a high GRACE score of 140 or more.  But "immediate" was a mean of 16 hours, which is not immediate!  Furthermore, they excluded patients with ongoing chest pain; this exclusion was not stated in the methods.  But I know they excluded these patients because I emailed the first author, Dr. Mehta, and he replied that "I doubt investigators would have enrolled pts with ongoing CP in this NSTEACS trial."

Many readers of this blog, and providers who attend my ECG talks, ask me:

"How can I get my interventionalist to take these patients to the cath lab?"

My answer:

Tell them "Your own guidelines state that these patients with refractory pain should go within 2 hours."

The only caveat is that you must be certain that the symptoms, ECG findings, and elevated troponin are due to acute coronary syndrome, and not another etiology of type II MI, such as hypotension, tachy- or bradycardia, anemia, aortic stenosis, hypoxia, etc.

Guideline quotes


4.4.4. Early Invasive and Ischemia-Guided Strategies: Recommendations
Class I
1. An urgent/immediate invasive strategy (diagnostic angiography with intent to perform revascularization if appropriate based on coronary anatomy) is indicated in patients (men and women) with NSTE-ACS who have refractory angina or hemodynamic or electrical instability (without serious comorbidities or contraindications to such procedures) (42, 44, 138, 338). (Level of Evidence: A)

European Society of Cardiology:
5.6.3 Timing of invasive strategy Immediate invasive strategy (less than 2 hours):
Very-high-risk NSTE-ACS patients (i.e. with at least one very-high-risk criterion: hemodynamic instability, Recurrent or ongoing chest pain refractory to medical treatment, life threatening arrhythmias or cardiac arrest, mechanical complications of MI, acute heart failure, recurrent dynamic ST-T wave changes, particularly with intermittent ST elevation) according to Table b) have been generally excluded from RCTs.  Owing to a poor short- and long-term prognosis if left untreated, an immediate (i.e. less than 2 h from hospital admission, analogous to STEMI management) invasive strategy with intent to perform revascularization is recommended, irrespective of ECG or biomarker findings.


1.  Roffi M, Patrono C, Collet JP, et al. 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation: Task Force for the Management of Acute Coronary Syndromes in Patients Presenting without Persistent ST-Segment Elevation of the European Society of Cardiology (ESC). European heart journal 2016;37:267-315.

2. Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2014;130:e344-426.

3. Mehta SR, Granger CB, Boden WE, et al. Early versus delayed invasive intervention in acute coronary syndromes. The New England journal of medicine 2009;360:2165-75.

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