Predicting Coronary Stenosis by Computer-Enhanced, Resting Electrocardiogram Effect of Gender, Age,...

Predicting Coronary Stenosis by Computer-Enhanced, Resting

Electrocardiogram Effect of Gender, Age, and

Revascularization on Sensitivity and Specificity

E. Grube1, A. Bootsveld2, S. Yuecel1, L. Buellesfeld1, J.T. Shen3, M. Imhoff4,

1Heart Center Siegburg, Siegburg, Germany

2Ev. Stift St. Martin, Koblenz, Germany3Premier Heart, Port Washington, NY, USA

4Ruhr-University Bochum, Germany

2 © M. Imhoff, 2007

Computerized Resting ECG AHA Scientific Sessions 2007

Disclosures

• Dr. J.T. Shen is founder and managing member of Premier Heart LLC and co-inventor of the web-based 3DMP method.

• The other authors have no disclosures to make.

3 © M. Imhoff, 2007


3DMP

Digital Database Driven Multi Phase• A computerized expert ECG System

• Sophisticated mathematical analysis

• Validated digital patient database

• An innovative, non-invasive diagnostic device for myocardial ischemia due to coronary artery disease

4 © M. Imhoff, 2007


Signal and Digital Data Processing

Leads II and V5 recorded for 82s

Amplify, digitizeand FFT

Signal averaging16 segments at 5.12s

@ 100 Hz

Six mathematical transformations

Positive indices identified

Patterns matched against a 35,000-patient database

Amplify, digitize, encrypt and transmit

Decryption FFT

Automatic Report Generation

5 © M. Imhoff, 2007


3DMP Database

• 35,000 cases • Confirmed medical diagnosis

• Benchmark references for pattern recognition

• Proprietary software for data interpretation• Automated comparison to database

• Diagnosis of myocardial ischemia

• Automatic scoring system• Quantitative assessment of severity of myocardial ischemia

6 © M. Imhoff, 2007


Clinical Study

• Previous study (Weiss et al, 2002) showed good sensitivity and specificity of 3DMP in the prediction of hemodynamically relevant coronary stenosis

• Large single-center convenience sample of an unselected patient population scheduled for coronary angiography

• Comparison to angiography

• Focus on effect of gender, age, and previous revascularization on performance of the method

7 © M. Imhoff, 2007


Patients

• 758 patients scheduled for angiography• 277 female , 65.3 +/- 10.6 yoa• 481 male, 60.5 +/-10.7 yoa• 433 under 65 yoa, • 325 65 yoa and over

• 545 patiens without previous coronary intervention • 61.6 +/- 11.2 yoa, 38% female

• 213 patients after coronary revascularization at least 6 weeks before study• 63.8 +/- 9.8 yoa, 32% female• 147 PCI, 63.2 +/-10.3 yoa

• 55 female (37%), 68.6 +/- 7.8 yoa• 92 male (63%), 60.0 +/- 10.2 yoa

• 66 CABG, 65.3 +/- 8.6 yoa• 13 female (20%), 66.3 +/- 10.0 yoa• 53 male (80%), 65.0 +/- 8.3 yoa

8 © M. Imhoff, 2007


Coronary Angiography

• Standard procedures

• Immediate classification of results by angiographer

• Independent classification by second cardiologist

• Dichotomous classification of hemodynamically relevant coronary stenosis

• Stenosis “NO”: < 70% stenosis (< 50% LCA)

• Stenosis “YES”: > 70% stenosis (> 50% LCA)

• Both investigators blinded against 3DMP results

9 © M. Imhoff, 2007


3DMP ECG

• Prior to angiography after 20 min rest• Limb leads and V5• 82 second simultaneous recording of leads II and V5• Amplification, digitization, transmission to central server (after

ECG quality check)• Calculation of severity score (0 to 20)

• Higher values associated with higher likelihood of coronary stenosis

• Cut-off > 4 indicative of hemodynamically relevant stenosis

• ECG technician and Premier Heart staff blinded against angiograms

10 © M. Imhoff, 2007


Coronary Stenosis

• 319 of 758 patients (42%)• 46% primary• 28% post PCI• 46% post CABG

• Overall, stenosis more frequent in men and older patients

• No gender or age differences after revascularization

female

male

Sex

11 © M. Imhoff, 2007


Severity Score

Coronary Stenosisyesno

Sev

erit

y S

core

14

12

10

8

6

4

2

0

12 © M. Imhoff, 2007


Severity Score


Sev

erit

y S

core

14

12

10

8

6

4

2

0


Sev

erit

y S

core

14

12

10

8

6

4

2

0

malefemale

Gender

65+< 65

Age group

13 © M. Imhoff, 2007


Severity Score

14 © M. Imhoff, 2007


1 - Specificity

1,00,80,60,40,20,0

Sen

siti

vity

1,0

0,8

0,6

0,4

0,2

0,0

1 - Specificity

1,00,80,60,40,20,0

Sen

siti

vity

1,0

0,8

0,6

0,4

0,2

0,0

ROC Curves

Reference Line

All pts (AUC 0.873)

Source of the Curve

Reference Line

65+ yoa (AUC 0.838)

<65 yoa (AUC 0.892)

male (AUC 0.869)

female (AUC 0.880)

Source of the Curve

15 © M. Imhoff, 2007


ROC Curves

1 - Specificity

1,00,80,60,40,20,0

Sen

siti

vity

1,0

0,8

0,6

0,4

0,2

0,0

Reference Line

male, 65+ yoa (AUC 0.827)

male, <65 yoa (AUC 0.887)

female, 65+ yoa (AUC 0.859)

female, <65 yoa (AUC 0.886)

Source of the Curve

1 - Specificity

1,00,80,60,40,20,0

Sen

siti

vity

1,0

0,8

0,6

0,4

0,2

0,0

Reference Line

any revasc (AUC 0.909)

CABG (AUC 0.891)

PCI (AUC 0.907)

no revasc (AUC 0.857)

Source of the Curve

16 © M. Imhoff, 2007


Prediction of Coronary Stenosis

Angiography

No Stenosis

Stenosis

3DMP Severity Score

< 4 376 63

>= 4 35 284

17 © M. Imhoff, 2007


n a priori Correct Sens Spec PPV NPV

Total 758 0,421 0,871 0,890 0,856 0,766 0,937

Female 277 0,303 0,884 0,893 0,881 0,587 0,977

Male 481 0,489 0,863 0,889 0,837 0,833 0,892

< 65 years 433 0,379 0,875 0,860 0,885 0,735 0,944

65+ years 325 0,477 0,865 0,923 0,812 0,803 0,927

No Revasc 545 0,455 0,859 0,879 0,842 0,795 0,909

PCI 147 0,279 0,898 0,878 0,906 0,582 0,980

CABG 66 0,455 0,909 1,000 0,833 0,806 1,000

18 © M. Imhoff, 2007


Summary

• Computerized resting ECG analysis

• Prediction of coronary stenosis• 87% correct predictions, sensitivity 89%, specificity 86%

• adjusted PPV 77%

• adjusted NPV 94%

• No significant effects on performance fromGender, Age, Type of Revascularization

• Further studies warranted (and planned)

19 © M. Imhoff, 2007


Conclusions

• Non-invasive screening for coronary artery stenosis

• Feasible in patients with contraindications to stress testing

• Similar rule-out performance like stress testing(awaits further study)

• Simple applications by technicians

• Presence of a physician not required

Predicting Coronary Stenosis by Computer-Enhanced, Resting Electrocardiogram Effect of Gender, Age,...

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