EBQ:Sgarbossa Criteria Study

Under Review Journal Club Article

Sgarbossa E. et al.. "Electrocardiographic diagnosis of evolving acute myocardial infarction in the presence of left bundle-branch block. GUSTO-1 (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries) Investigators". NEJM. 1996. 334(8):481-7.
PubMed Full text PDF

Clinical Question

How can we diagnose Acute Myocardial Infarction in patients with a Left Bundle Branch Block?

Conclusion

Sgarbossa's Criteria is a validated clinical prediction rule based on ECG criteria to diagnose Acute Myocardial Infarction in patients with a Left Bundle Branch Block. It has good specificity, but poor sensitivity.

Major Points

The Sgarbossa Criteria:

1. ST-segment Elevation of at least 1 mm with concordance with the QRS complex with a score of 5
2. ST-segment depression in leads V1, V2 or V3 with a score of 3
3. ST-segment Elevation of atleast 5 mm with discordance with the QRS complex with a score of 2

With a score >3 90% of those with positive criteria will have STEMI (Good Specificity) But with negative criteria it doesn't help that much (Low sensitivity)

Population

Patient Demographics

• Median Age: 68 years
• Males: 64% in study group and 60% in experimental group
• Left Axis Deviation: 28% Vs. 48%
• Previous MI: 26% Vs. 59%

Inclusion Criteria

• Experiment: Patients with LBBB and Acute myocardial infarction (GUSTO-1 trial population)
• Control: Patients with normal documented angiography with LBBB Randomly selected from Duke data bank for cardiovascular disease

Exclusion Criteria

Patients without LBBB

Outcomes

• Using univariate analysis the ods rations for the individual criteria for STEMI in the presence of LBBB were:

Criteria	Odds Ratio
ST-segment elevation ≥ 1mm and concordant with QRS complex	25.2 (11.6-54.7)
ST-segment depression ≥ 1mm in lead V1, V2, V3	6.0 (1.9-19.3)
ST-segment elevation ≥ 5mm and discordant with QRS complex	4.3 (1.8-10.6)

Primary Outcome

Acute Myocardial Infarction

Criticisms & Further Discussion

• The Sgarbossa criteria have not been incorporated into the AHA STEMI guidelines and new LBBB has been removed from the current AHA recommendations for activation of PCI.
• Although the criteria is highly specific it lacks sensitivity and can result in excess cath lab activations

Funding

Grant from Bayer, Genentech, CIBA–Corning, ICI Pharmaceuticals, and Sanofi Pharmaceuticals.