sinaiem.org

A number of you have asked for a recap on Dr. Hollander’s approach to treating NSTE ACS. You can download the audio from his talk on the Conference website. I’ve gone through it again and have some citations below. His talk is indeed guideline-based (all from the ACC/AHA 2007 NSTEMI / UA guidelines — familiarize yourself with their classes of recommendations and their grading the level of evidence) but also this portion of his talk was explicitly featured in a pharmaceutical-industry sponsored event. So, as always, approach this with a skeptical mind, and please share your findings in the comments section:

For early risk stratification of NSTE ACS, the recommendations are:

• EKG within 10 min, and repeat if high suspicion (I-B)
• Biomarkers immediately and repeated within 8-12 hours of  symptom onset (I-B) (note: according to guidelines, can be 2 hours after initial set)
• Risk-stratify with TIMI or PURSUIT scoring (IIa-B)
• Search for other causes of chest pain (IB)

A big problem with the 2007 guidelines is, in Dr. Hollander’s view, the early (Step 1) bifurcation between “Early Invasive” and “Conservative” therapy, especially since the decision to cath must be made before any drugs are given. Furthermore, “Early Invasive” actually means cath within 24-48 hours — so going to cath tomorrow is hardly “early” to us in EM but still guideline-compliant to the cardiologists. Who should would benefit from the initial invasive strategy? Any patient with any of the following (Class I A):

• Age over 75
• TIMI score > 3
• Elevated biomarkers
• Recurrent chest pain
• Diabetes
• Signs of CHF, or LVEF < 40%
• Sustained VT or hemodynamic instability (thanks)
• ST changes (um, ok)
• Recent PCI, prior CABG (again, thanks)

Conservative strategy (I-B) is recommended for those with atypical chest pain, hemodynamic and rhythm stability, TIMI <3, or those cases in which the patient or doc refuses cath.

Both invasive and conservatively-managed patients should get O2 (I-C), SL NTG (I-C), IV nitrates for BP and pain control (I-B) (but never below 90 SBP), beta-blocker PO within 24 hours if no contraindications (I-B, used to be I-A, and IV is class II — thanks to COMMIT). Even though we stress about the beta-blockers, there’s better evidence (I-A) to give an ACE-I PO within 24 hours to diabetics or CHF patients.

Now, in patients for whom invasive strategy is selected, there’s I-A evidence to support enoxaparin (lovenox) or unfractionated heparin (UFH). Alternatively, there’s also I-B evidence to give bivalirudin (not yet popular) or fondaparinux (not yet FDA approved for this).

Now, where it gets a little complicated is anti-platelet therapy for the invasive strategy patients. First, straightforward, there’s I-A evidence to support immediate aspirin unless active GI bleed or anaphylaxis history (ASA decreases mortality as much as streptokinase). And there’s also I-A evidence to do ONE of the following: For patients in whom PCI is planned, IIb/IIIa inhibition plus ASA and heparin pre-PCI… OR… clopidogrel 300mg load up front, then 75mg a day (note: Some cardiologists frown on the latter, since it essentially takes CABG off the table for a week). Finally, there’s IIa-B evidence that you can skip the IIb/IIIa inhibitor if you gave bivalirudin and clopidogrel at least 6 hours pre-cathand cath is planned within 24 hours (no patient can tell you when cath is really planned, so many ED docs skip this).

There’s no new data on GP IIb/IIIa inhibitors since 2002 guidelines, and the data we do have show no benefit to low-risk patients (TIMI <3) and while there’s a 15% RRR in mortality in patients getting IIb/IIA who go on to PCI, there’s no benefit in starting IIb/IIIa antagonists prior to cath. The guidelines for invastive strategy patients are I-A clear, however: initiate one of the following before angiography: clopidogrel, or IIb/IIIa inhibition (there’s IIa-B evidence that you can give both).

For conservative strategy patients, the meds are: ASA on arrival (I-A), clopidogrel if ASA is not tolerated (I-A), and clopidogrel should be added to ASA “as soon as possible after admission” (I-A, and please note, Dr. Hollander’s slide said “ASA/Clopidogrel on arrival” and this confused many). These guidelines are based on the CURE trial (NEJM 2001; 345:494-502).

There’s also I-A evidence for conservative strategy patients that regimens with enoxaparin or UFH given “as soon as possible” after arrival “have established efficacy” and I-B evidence for fondaparinux, and IIa-B evidence that enoxaparin and fondaparinux are preferred over UFH unless “CABG is planned with 24 hours” (and as Dr. Hollander notes, CABG is rarely planned — for the record, according to CRUSADE 10% of NSTEMI patients end up with CABG, but just 0.3% go emergently. He says it’s the rare doctor that’s inconvenience by enoxaparin, and since patients are going to wait in many cases a good long while before cath, it’s best to get the best 1-A meds on board as soon as possible, and that’s why he prefers lovenox).

The differences between enoxaparin and UFH come largely from the SYNERGY trial, which we covered in journal club…

Posted on Thursday, July 24th, 2008 at 6:55 am by Nick. Filed under ACS, Blog.
You may post a comment.