Sunday, July 7, 2019

Would you have given thrombolytics to this NSTEMI patient?

Case submitted by Dr. James Alva

A middle aged male called EMS for chest pain. EMS arrived and confirmed that the patient was complaining of chest pain and shortness of breath.

They recorded this prehospital ECG:

What do you think?







Normal QRS complex rhythm with hyperacute T-waves in V2-V6, I and aVL. Slight STE in V2 only, with significant STD and thus de-Winter pattern in V4-V6. Leads II and III show reciprocal depression of the ST segment (II) and T-wave (III). This is diagnostic of acute myocardial infarction of the anterolateral walls, with the most likely etiology being Occlusion of the LAD. In other words, this ECG shows LAD OMI.

Why was ST depression excluded from thrombolytics in all the guidelines? (except in the American 2013 guidelines, in which it is indicated for 1) STD in V1-V4 of posterior MI and 2) widespread STD with STE in aVR.
The data:
The data on when to give thrombolytics is incredibly scant. All trials of thrombolytics vs. placebo had poorly defined ECG criteria for enrollment.  Those that required ST Elevation had no instructions in the methods of how to measure ST Elevation.  No study analyzed ECGs to determine subgroups that benefit except to classify as STE, STD, or T-wave inversion.  Only ISIS-2, GISSI-1, LATE, and TIMI IIIB enrolled patients with ST depression.  They enrolled those with as little as 1 mm of ST depression in only 1 lead.  There were small numbers of patients.  Very few were enrolled in less that 6 hours from pain onset.  And yet for years thrombolytics have been contraindicated in ST depression (STD).
In intervening years, syndromes of acute coronary occlusion (Occlusion MI-OMI) presenting as ST depression have been identified.  The 2 mentioned above have now been included in the guidelines, but de Winter's T-waves, although now recognized as representative of OMI, have not been included.

We (Smith and Meyers) would give thrombolytics for ACS with this ECG unless PCI is available.




Shortly after this ECG, the patient suffered a witnessed VF arrest. ACLS was started and continued without ROSC to the Emergency Department despite several shocks administered.

He arrived still in VF arrest. Several more shocks were administered with no change out of VF arrest. ECMO was not available at this institution, and it is the policy of interventional cardiology not to perform cath with ongoing chest compressions.

Dr. Alva correctly diagnosed "hyperacute T-waves anterolaterally" on the EMS ECG and decided to give tenecteplase as both ECMO and intra-arrest cath were not an option.

ROSC was achieved after two more rounds of CPR.

Here is his initial post-ROSC ECG:
Obvious huge anterior STEMI (obvious OMI). Assuming you correctly found the J-point!


The cath lab was activated based on this obvious STEMI, however cardiology refused and deactivated the cath lab. The reason given was that "the bleeding risk was too high" due to thrombolytics administration. However, angiography +/- PCI is not contraindicated immediately after administration of thrombolytics, although the incidence of increased bleeding is higher in the first 2-3 hours afterward (see literature review at the end of this post for current applicable STEMI and combination reperfusion strategy guidelines).


Here is his ECG 60 minutes after ROSC:
New RBBB with LPFB, with persistent but improving STE in V2-V5. Decreasing STE and T-wave inversion in leads with STE implies that the artery is open, and reperfusion is in progress.

Rhythm is accelerated idioventricular rhythm, another sign of reperfusion



Here is his ECG 90 minutes after ROSC:
Back to normal QRS complex with continuing improvement of STE. This ECG alone would still be barely diagnostic of hyperacute T-waves in V2-V4 in the right clinical context.



Troponin T rose to 13.0 ng/mL (not ng/L! -- very high) and then was not further trended (peak troponin unknown).

Cardiac catheterization was performed the next day, approximately 24 hours after arrival, and showed a "hazy 80-90% mid LAD lesion" (TIMI flow not listed) which was successfully stented with resultant TIMI 3 flow and excellent angiographic result.

The patient survived.





Brief review and summary of combination reperfusion strategies:

Combination reperfusion strategies (thrombolytics plus PCI) constitute a large topic with many subcategories, however the relevant summary of our 2013 ACC/AHA STEMI Guidelines is:

Immediate transfer and PCI is recommended for:
 - all failed reperfusion ("rescue PCI", ST resolution less than 70%)
 - all high risk patients (hemodynamic / electrical instability)
 - all other patients may be transfered and PCI delayed for 2-3 hours after thrombolytics

Here is a relevant quote from our 2013 Guidelines:

TRANSFER FOR ROUTINE EARLY CORONARY ANGIOGRAPHY AFTER FIBRINOLYTIC THERAPY  

With the introduction of coronary stents and aggressive antiplatelet therapies, there has been renewed interest in immediate and early catheterization after fibrinolytic therapy. The advantage of this approach is that it can be initiated at non–PCI-capable hospitals and affords the healthcare system additional time to arrange a “nonemergency” transfer for angiography and PCI. Routine referral for angiography with the intent to perform PCI is supported indirectly by retrospective analyses from trials of fibrinolytic therapy that suggest that patients treated with PCI during the index hospitalization have a lower risk of recurrent MI and a lower 2-year mortality rate (365–367). The results of RCTs evaluating a strategy of routine catheterization after fibrinolysis are limited by small sample sizes or surrogate endpoints and have provided mixed results. Nevertheless, most trials have demonstrated improvement in clinical outcomes in patients transferred for early catheterization, most notably in higher-risk patients (357– 362,368–371) (Table 8 and Figure 3). In the GRACIA (Grup de Analisis de la Cardiopatia Isquemica Aguda) study (362), early catheterization within 6 to 24 hours of successful fibrinolysis in stable patients was compared with an ischemia-guided approach. It resulted in improved outcomes, including a significantly lower rate of death, reinfarction, or ischemia-driven revascularization at 1 year. The TRANSFER-AMI (Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction) study (360) was the largest (n=1059) of the RCTs evaluating transfer for coronary angiography and revascularization among high-risk patients and showed a significant reduction in the combined primary endpoint of death, recurrent MI, recurrent ischemia, new or worsening HF, or shock at 30 days with immediate transfer for the angiography group compared with conservative care. The findings from this and other studies indicate that high-risk patients with STEMI appear to benefit from immediate transfer for early catheterization, compared with either an ischemia-guided approach or delayed routine catheterization at 24 hours to 2 weeks (360,361). The reported benefits relate to a reduction in the incidence of recurrent infarction or ischemia, thus favoring earlier transfer and revascularization when possible.


In a meta-analysis (359) that included 7 RCTs of early transfer for catheterization, a strategy of routine early catheterization after fibrinolysis was associated with a statistically significant reduction in the incidence of death or MI at 30 days and at 1 year, without an increase in the risk of major bleeding. This meta-analysis was based on a mixture of trials that randomized high-risk patients (360,361,369) and trials that did not mandate the inclusion of high-risk subjects. A meta-regression analysis investigating the relative benefit of an invasive strategy after fibrinolysis according to the baseline risk of the enrolled patients for each trial suggested a larger proportional benefit with early catheterization and PCI in trials enrolling higher-risk patients (359)."






Although there is no specific recommendation regarding a patient who suffered out-of-hospital cardiac arrest, given lytics, and has a STEMI on their initial ROSC ECG, it is clear from the above ACC/AHA recommendations that they would intend for this patient to receive immediate angiography as soon as possible, and at the very least within 2-3 hours.




Learning Points:

This patient had witnessed VF arrest with prehospital ECG showing subtle but definite signs of LAD OMI without STEMI criteria. No literature exists yet on this specific population, but common sense tells us that intra-arrest thrombolytics are a reasonable option when both ECMO and intra-CPR cath are not available.

You must learn to recognize these subtle signs of OMI on ECG.

Immediate PCI after thrombolytics is recommended for all high risk patients, as well as those with evidence of thrombolytic failure. For all other patients, catheterization is recommended within 2-3 hours.

2 comments:

  1. truly incredible case. dr alva and his team saved this middle-aged man's life.
    i think i sent a similar case to dr smith a few months ago.
    patient presented with similar ecg. but no old-fashioned "STEMI" criteria. several questions:
    1. if i gave thrombolytics to ekg #1, would that be me being a "cowboy", unsupported with current guidelines? would it be "wrong". would i be vulnerable if there was a thrombolytic complication, eg, head bleed? i am talking about simply based on severe chest pain, and the ecg #1. (in my shop the patient needs to transferred to a nearby hospital, my door to their needle always greater than 90 minutes.)
    2. in my case, i gave aspirin, heparin nitro, pain resolved. as they loaded the patient onto the EMS stretchter for transfer the nurse called for morphine order, for recurrent chest pain. i said no, came to stretcher-side, and the medics did a stat ecg on their stretcher, now a STEMI that even the cardiologists could see, and we gave TNK on the medic stretcher.
    At the receiving hospital, i was told they waited they didn't cath till the next day, because of risk of bleeding. i spoke to the cardiologist who told me the "3 hour rule" (hold cath for 3-12 hours), i guess as long as they are "stable".

    but Dr Alva's and his team's save above is extraordinary, incredible work. and thank you, Pendell, for the excellent post and super-cool ecg's and discussion.
    tom.

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    Replies
    1. Regarding your Question, Tom — As per the comment by Dr. Meyers above — in a setting of new-onset severe chest pain — this 1st ( = Prehospital) ECG clearly shows DeWinter T waves in multiple chest leads + inferior lead reciprocal changes — so this is DIAGNOSTIC of acute OMI (acute LAD occlusion) UNTIL such time as it is proven otherwise. As a result — reperfusion therapy with thrombolytics (if timely cath/angioplasty not available) seems clearly indicated. So that those in your geographic area (hospital distribution) AGREE with this therapy (and that they will SUPPORT your use of it) — I suggest showing your consulting cardiologists this initial ECG and asking them to COMMIT to a treatment course for a case such as this for the receiving Emergency Physician. In my experience — it is best to know what your consultants’ thresholds for treatment are IN ADVANCE — and I find it hard to believe that any cardiologist told a patient is presenting with new severe chest pain and this 1st ECG will not agree that if timely cath is not available, that thrombolytic therapy IS the appropriate treatment for this case.

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