False Positive ST Elevation in Patients Undergoing Direct Percutaneous Coronary Intervention David M. Larson MD, Katie M. Menssen, BS,, Scott W Sharkey MD, James Harris MD, Jeffrey T. Meland, MD Robert Schwartz MD, Barbara T Unger RN, Timothy D. Henry MD, Ridgeview Medical Center, Waconia, Minnesota and Minneapolis Heart Institute Foundation, Minneapolis, Minnesota

Introduction Previous data shows that up to 11% of STEMI patients treated with thrombolysis did not have a Myocardial Infarction (MI) ACC/AHA guidelines recommend that the Emergency physician make the decision regarding reperfusion therapy for STEMI There is limited data reporting the rate of “false positive” ECGs in STEMI patients treated with Percutaneous Coronary Intervention.

Previous data shows that up to 11% of STEMI patients treated with thrombolysis did not have a Myocardial Infarction (MI)

ACC/AHA guidelines recommend that the Emergency physician make the decision regarding reperfusion therapy for STEMI

There is limited data reporting the rate of “false positive” ECGs in STEMI patients treated with Percutaneous Coronary Intervention.

Objective To determine the incidence and etiologies of “false positive” ECGs, defined as: no culprit coronary vessel and negative cardiac markers (no MI), from a non-selected cohort of STEMI patients. To determine the incidence of “true false positive” ECGs defined as no culprit, no significant coronary disease and negative cardiac markers.

To determine the incidence and etiologies of “false positive” ECGs, defined as: no culprit coronary vessel and negative cardiac markers (no MI), from a non-selected cohort of STEMI patients.

To determine the incidence of “true false positive” ECGs defined as no culprit, no significant coronary disease and negative cardiac markers.

Methods Minneapolis Heart Institute/Abbott Northwestern Hospital (ANW) – a tertiary cardiac center with referral relationships with 30 community hospitals (CH) in Minnesota and Wisconsin – instituted the “MHI Level 1 MI Program” in 2003.

Minneapolis Heart Institute/Abbott Northwestern Hospital (ANW) – a tertiary cardiac center with referral relationships with 30 community hospitals (CH) in Minnesota and Wisconsin – instituted the “MHI Level 1 MI Program” in 2003.

Methods Level 1 MI Protocol: Includes STEMI (ST elevation or new Left Bundle Branch Block) with symptom < 24hrs. Diagnosis and decision to activate the cath lab is made by the Emergency Physician at the presenting hospital. Transferred patients go directly to cath lab for Primary or Facilitated PCI Data obtained from a prospective registry of all “Level 1 MI” patients that includes clinical, laboratory, ECG, angiographic and follow up data.

Level 1 MI Protocol: Includes STEMI (ST elevation or new Left Bundle Branch Block) with symptom < 24hrs. Diagnosis and decision to activate the cath lab is made by the Emergency Physician at the presenting hospital. Transferred patients go directly to cath lab for Primary or Facilitated PCI

Data obtained from a prospective registry of all “Level 1 MI” patients that includes clinical, laboratory, ECG, angiographic and follow up data.

What is the prevalence and etiology of “False Positive” Cath Lab Activation? STEMI Larson, DM et al JAMA 2007;298(23):2754-2760

The Clinical Challenge Denying Reperfusion Falsely Declaring an Emergency Larson, DM et al JAMA 2007;298(23):2754-2760

Definitions of “False Positive” Cardiac Cath Lab Activation No culprit No significant coronary disease Negative cardiac biomarkers Larson, DM et al JAMA 2007;298(23):2754-2760

No culprit

No significant coronary disease

Negative cardiac biomarkers

Results from the Level 1 MI Program From 3/03 to 11/06, 1,345 STEMI patients enrolled in Level 1 MI program including 1,048 transferred from 30 rural or community hospitals. 149 (11.2%) had normal cardiac biomarker levels. Larson, DM et al JAMA 2007;298(23):2754-2760

From 3/03 to 11/06, 1,345 STEMI patients enrolled in Level 1 MI program including 1,048 transferred from 30 rural or community hospitals.

149 (11.2%) had normal cardiac biomarker levels.

“ False Positive” Cath lab Activations STEMI Diagnosis N=1,345 Angiography N=1,335 5 died prior to angio 5 Case canceled Multiple potential culprits N=10 (0.7%) Clear culprit N=1138 (85.3% No Angiographic Culprit N=187 (14%) Larson, DM et al JAMA 2007

No Significant CAD N = 127 (9.5%) Positive Cardiac Markers N= 48 (38%) Negative Cardiac Markers N = 44 (73%) No Culprit N=187 (14%) Mod-Severe CAD N =60 (4.5%) Positive Cardiac Markers N= 16 (27%) Negative Cardiac Markers N = 79 (62%)

With a culprit Multiple Potential Culprits N=10 Positive Cardiac Markers N= 10 Negative Cardiac Markers N = 26 Clear culprit N=1138 Positive Cardiac Markers N= 1112 Negative Cardiac Markers N = 0 Larson, DM et al JAMA 2007

Positive Cardiac Markers N= 64 (4.8%) Negative Cardiac Markers N = 123 (9.2%) No Angiographic Culprit N=187 (14%) Larson, DM et al JAMA 2007 Early repolarization 25 Non-diagnostic ECG 21 Pericarditis 20 Prior MI 20 LBBB 11 LVH 8 Vasospasm 4 Tachycardia related 3 RBBB 3 Pacemaker 3 Brugada syndrome 1 Aortic dissection 1 Unknown 3 Stress Cardiomyopathy 17 Myocarditis 15 Prior MI 9 STEMI –embolic/spasm 9 LBBB 4 NSTEMI 2 Pulmonary embolus 2 Aortic neoplasm 1 Severe aortic stenosis 1 Drug overdose 1 Unknown 3

No culprit and negative markers by Hospital ED Volume ED visits/year Not significant Larson, DM et al JAMA 2007

Left Bundle Branch Block New or presumed new LBBB observed in 36 (2.6%) of patients No culprit: 16 (44%) No significant CAD: 10 (27%) Negative cardiac biomarkers: 13 (36%) 30 day mortality in those with new LBBB was 8.3% Larson, DM et al JAMA 2007;298(23):2754-2760

New or presumed new LBBB observed in 36 (2.6%) of patients

No culprit: 16 (44%)

No significant CAD: 10 (27%)

Negative cardiac biomarkers: 13 (36%)

30 day mortality in those with new LBBB was 8.3%

Gender differences 381 (28.3%) women enrolled in Level 1 registry No culprit: 17.1% women vs 12.7% men (p=0.04) No significant CAD: 13.6% women vs 7.9% men (p=0.001) Negative biomarkers: 12.3% women vs 10.6% men (p=0.36) Stress cardiomyopathy may account for differences Larson, DM et al JAMA 2007;298(23):2754-2760

381 (28.3%) women enrolled in Level 1 registry

No culprit: 17.1% women vs 12.7% men (p=0.04)

No significant CAD: 13.6% women vs 7.9% men (p=0.001)

Negative biomarkers: 12.3% women vs 10.6% men (p=0.36)

Stress cardiomyopathy may account for differences

Summary: Incidence of “False Positive” Cath Lab Activation No culprit: 14% Normal or Minimal CAD: 9.5% Negative cardiac markers: 11.2% Combination of no culprit and negative biomarkers: 9.2% Larson, DM et al JAMA 2007;298(23):2754-2760

No culprit: 14%

Normal or Minimal CAD: 9.5%

Negative cardiac markers: 11.2%

Combination of no culprit and negative biomarkers: 9.2%

Conclusions The incidence of “false positive” ECGs in STEMI patients treated with Primary PCI is similar to previous data in patients treated with thrombolytic therapy. Patients presenting with “False Positive” ST elevation are a heterogeneous group, many with other serious cardiac conditions.

The incidence of “false positive” ECGs in STEMI patients treated with Primary PCI is similar to previous data in patients treated with thrombolytic therapy.

Patients presenting with “False Positive” ST elevation are a heterogeneous group, many with other serious cardiac conditions.