Chest Pain and

Evaluation of

Cardiac Ischemia

PAUL T CONNOR MD FACC

DIRECTOR PH-SJMC ECHO LAB AND CARDIAC REHABILITATION

ASSOCIATE MEDICAL DIRECTOR GENERAL CARDIOLOGY

What is the most accurate non-

invasive test to diagnose cardiac

ischemia ?

1. Regular Treadmill stress test

2. Treadmill Stress Echo

3. Nuclear Treadmill stress test

4. Pharmacalogic Nuclear stress test

5. Multi-slice Cardiac CTA

Scope of the Problem -CAD

Coronary Artery Disease is #1 killer in US

500,000 Deaths annually

1.2 million New Myocardial infarctions

16 million living with angina or CAD

500,000 New Cases of Angina per year

50% of Healthy 40yo males will get CAD

The Scope of the Problem – Chest Pain

10% of ER visits are for Chest Pain

10-12 million ER visits for CP

This does not include visits to primary care offices

2% short term mortality for miss-diagnosis of ACS

Approximately 20-30% of patients presenting with unstable angina will have a non-ischemic EKG

Cost > $10 Billion/yr

4 Million stress tests /yr

The Evaluation Dilemma

No perfect test to assess for all causes of chest

pain

No perfect test to assess for just cardiac causes of

chest pain.

Misdiagnosis can be life threatening

Aortic dissection

Pulmonary embolus

Acute coronary syndrome

PITFALLS TO CAD DETECTION

Stress tests can detect ischemia when blood flow is limited by > 70-75%

Majority of Heart Attacks occur when blockage is < 50%, the average narrowing for a heart attack is 20%

Only 14% of Heart Attack occur with a blockage of >75%

Chest Pain in the Emergency Room

TIMI Risk Score

TIMI Risk Score

Elevated Trop

EKG changes

Age >/65

Aspirin Use in last week

2 or more Chest pain events in last 24 hr

>/ 3 Card Risk Factors

Known CAD of 50 %

Does not take into other high risk markers

Chronic Renal Failure, CHF, DM

Looks at Death only not ACS – even 0 or 1 score has up to 5% event , 2-3 have 8-13%, 4-5 have 20-25%, 6-7 have 40%

HEART Score

History – high suspicion 2, medium 1

EKG – ST depress 2, Nonspec 1

AGE – 45-65 – 1, >65 – 2

Risk Factors – 1-2 gets 1, >/3 gets 2

Trop – 1-3X NL -1 , >3X NL – 2

Score 0-3 , low risk <2% 6 wk MACE

Includes – Death, MI and Revasc

5 Level ER Chest Pain System

Level 1 – STEMI – Direct to Cath Lab – DTB time <90 min

Level 2 – NSTEMI/ACS - + Trops/ acute ST –T abnl/ Chest pain sx

Consider Early Invasive Strategy – cath within 48 hrs

Level 3 – Nl Trops – Non-ischemic EKG – With Typical symptoms > 30

min but no prior CAD OR Atypical symptoms > 30 min but known

CAD

Pursue ischemia /risk stratification workup as OBS/Inpatient

Level 4 – Nl Trops/EKG/No CAD hx/ No high risk features

(CHF/ARF/DM) / Atypical symptoms

Consider ER risk stratification with D/C home if negative– Reg TM, Resting

MPI, Card CTA, Early outpt stress test within 24 hr

Level 5 - Unlikely Cardiac cause after initial ER evaluation, D/C with PCP follow up

Chest pain Cath

INTERVENTIONAL CARDIOLOGY ALGA RHYTHM

Chest Pain Evaluation in the Office

Evaluate the Story/Assess baseline Risk / Likelihood of

disease/ EKG

Testing Options

Regular Treadmill

Echo Stress test – treadmill or dobutamine

Nuclear perfusion stress test – treadmill or

pharmacologic

Cardiac Calcium Score

Cardiac CTA

Cardiac Cath/ FFR

Bayesian Theory

Post test likelihood of Disease is based

on the Pre-test likelihood of Disease

High Risk patient population even

with a normal test still have a

substantial risk of having the disease

Low Risk population even with a

positive test still have a low risk of

having the disease

Age

(y)

Gender Typical/Definite Angina

Pectoris

Atypical/Probable

Angina Pectoris

Nonanginal

Chest Pain

Asymptomatic

30-39 Men Intermediate Intermediate Low Very low

Women Intermediate Very low Very low Very low

40-49 Men High Intermediate Intermediate Low

Women Intermediate Low Very low Very low

50-59 Men High Intermediate Intermediate Low

Women Intermediate Intermediate Low Very low

60-69 Men High Intermediate Intermediate Low

Women High Intermediate Intermediate Low

Treadmill Stress Testing

Excellent prognostic data

by assessing functional

status

Most accurate with

normal baseline EKG

If > 10 Mets exercise

capacity without exercise

induced angina or

ischemic EKG changes –

very low event rate

Sensitivity 70-90% but

Specificity only 50-75%

Stress Echo

Assessment of ischemia / low perfusion by searching for

myocyte stunning and resultant hypocontractile state

Increases Sensitivity / Specificity compared to Regular

Treadmill , especially if baseline EKG not normal.

Captures other causes of exertional symptoms – LV

dysfunction, Valvular heart disease, Pulmonary HTN

No Radiation exposure and lower cost

Very dependent on getting high quality images – Body

habitus / COPD

Need to get a good exercise effort – even if HR goes up

above 85% MPR in stage 1 not enough myocardial

recruitment to induce ischemic changes

Nuclear Perfusion Imaging

Looking for impaired cardiac flow , not hypocontractile states

Occurs earlier on ischemic cascade

Excellent prognostic data over many decades of research

<1% annual event rate for 24 months post normal study

More sensitive but less specific than stress echo

Also sensitive to body habitus / artifacts but can be corrected with

software AC packages or PET /CT

Big worry with multiple studies is radiation exposure – approximately

14 mSv / study

Pharmacologic stress less predictive of good outcomes than treadmill stress – even with normal perfusion images event rate 1.5 -2% vs < 1% with normal treadmill performance.

Cardiac

CTA

Cardiac CTA

First non-invasive test to look at anatomy not ischemia

Very high negative predictive value – nearing 99%

Radiation doses continue to trend down with “Flash”

protocol

Image resolution improves with increasing detectors and

scan speeds

If good images and no CAD on CTA , extremely low event

rate

Less Specific – Is the moderate CAD ischemia producing

or not?

Romicat 2- 1000 pts in ER with low to intermediate risk chest pain, without prior CAD and f/u

at 28 days,

- Randomized to Cardiac CTA or “ Usual Care”

- Almost ½ female, average age 55, ½ had 2-3 Cardiac Risk Factors

- BMI <40, Nl Renal Fxn, nl EKG and initial Troponin

- Similar MACE Rate 0.4 – 1% at 28 Days

- LOS 23 hr for CTA with 60% discharged by 9 hrs vs 30 hr for usual care

- Direct D/C from EF 47% for CTA vs 12%

- Cath Rate 12% vs 8%

- Cost similar

- Radiation 14 mSv for CTA vs 5mSV

CT-STAT

- 700 patients in ER with Chest Pain, TIMI Risk Score

<4

- Randomized CTA to MPI

- Time to diagnosis 3 Hr for CTA vs 6 hr MPI

- Similar MACE 0.8 CTA vs 0.4 %

- Cost $2137 for CTA vs $3458

Promise Trial

10,000 outpatients being evaluated for chest pain and followed for 2 yrs

Average 60yr, 53% females, with average of 2.5 Cardiac Risk Factors

10% had ETT, 22% had Stress Echo, 68% had Nuclear MPI

MACE similar 3.3% CTA, 3% for functional testing ( NS)

Cost Similar – CTA higher by $300/patient over 3 yrs, Radiation slight higher CTA 12

vs 10 mSV

Cath Rate increased with CTA 12 % vs 8% with Functional testing

3.4% had nonobstructive CAD at Cath in CTA vs 4.3% with functional testing

Excellent Negative predictive value

The Horizon – FFR CTA

What is the most accurate non-

invasive test to diagnose cardiac

ischemia ?

1. Regular Treadmill stress test

2. Treadmill Stress Echo

3. Nuclear Treadmill stress test

4. Pharmalogic Nuclear stress test

5. Multi-slice Cardiac CTA