Cardiac - The MarketCardiac - The Market

Heart disease is the number one Heart disease is the number one killer of American men and womankiller of American men and woman

Some 650,000 American’s will die Some 650,000 American’s will die this year in the United Statesthis year in the United States

Early detection and medical therapy Early detection and medical therapy can effectively treat the diseasecan effectively treat the disease Lipid controlLipid control Risk factor modificationRisk factor modification

Tools for risk Tools for risk stratificationstratification

Treadmill evaluationTreadmill evaluation Low sensitivity, moderate specificityLow sensitivity, moderate specificity

Stress EchocardiogramStress Echocardiogram Perfusion imagingPerfusion imaging

Sensitive and specific but still false positives Sensitive and specific but still false positives and false negativesand false negatives

Rb-82 higher diagnostic accuracy relative to Rb-82 higher diagnostic accuracy relative to SPECTSPECT

Coronary calcium screeningCoronary calcium screening Viability Viability Coronary angiographyCoronary angiography

The cardiac imaging The cardiac imaging market is transitioningmarket is transitioning

SPECT PET Cardiac catheterization CT

angiography

SPECT perfusion SPECT perfusion imagingimaging

Low diagnostic accuracy in some

patient populations-Balanced ischemia

Long Acquisition times

Higher radiation exposure

Decreasing reimbursement

SPECT perfusion SPECT perfusion imagingimaging

Low energy photonsLow energy photons Thallium or Tc basedThallium or Tc based

Usually two imaging sequences (20-30 Usually two imaging sequences (20-30 minutes each)minutes each)

Total exam time 3-4 hoursTotal exam time 3-4 hours Study of over 3000 patient with ThalliumStudy of over 3000 patient with Thallium

Sensitivity 84% and Specificity 53%Sensitivity 84% and Specificity 53% Attenuation/motion all impact relative Attenuation/motion all impact relative

accuracyaccuracy Equivocal studies men 10% woman 30-40%Equivocal studies men 10% woman 30-40%

Case studyCase study

50yo female patient with breast 50yo female patient with breast implantsimplants

MPS ordered for evaluation of chest MPS ordered for evaluation of chest pain syndrome with equivocal GXTpain syndrome with equivocal GXT

Patient underwent MPS with Tc-99m Patient underwent MPS with Tc-99m Sestamibi Sestamibi

Patient then underwent Rb-82 PET Patient then underwent Rb-82 PET perfusion perfusion

SPECT

PET

Case StudyCase Study

Comparison between SPECT and Comparison between SPECT and PET PET

Normal scan with Rb-82 PETNormal scan with Rb-82 PET Abnormal with SPECTAbnormal with SPECT False positive SPECT, patient risk False positive SPECT, patient risk

stratified away from invasive stratified away from invasive evaluationevaluation

No cardiac events in follow upNo cardiac events in follow up

PET perfusion imagingPET perfusion imaging

High diagnostic accuracy regardless of patient status-Gate both stress and rest

Shorter acquisition times

Lower radiation exposure

Increasing reimbursement

82Rb +

-

p

PET perfusion PET perfusion

2. Nuclear Medicine Self-Study Program III: Nuclear Medicine Cardiology. Botvinik, EH, Ed. 1998: Society of Nuclear Medicine, Reston, VA.

Author Sensitivity Specificity # Patients

Gould 95% 100% 50

Demer 94% 95% 193

Go 93% 78% 202

Schelbert 97% 100% 45

Yonekura 93% 100% 49

Williams 98% 93% 146

Stewart 84% 88% 319

Weighted Avg.

93% +/- 8 92% +/- 5 766

Economic impact on Economic impact on societysociety

Single missed diagnosis of CAD-$90,000Single missed diagnosis of CAD-$90,000 Comparison of SPECT and PETComparison of SPECT and PET

300 patients 300 patients SPECT over 32% referred for coronary SPECT over 32% referred for coronary

angiographyangiography PET only 10% referred for coronary PET only 10% referred for coronary

angiographyangiography Additionally 20% of catheterization were normal Additionally 20% of catheterization were normal

in the face of a abnormal SPECT study (false in the face of a abnormal SPECT study (false positives)positives)

PET imaging lead to a cost savings of 30-40%PET imaging lead to a cost savings of 30-40%

Impact of PET on health care cost prepared for General Motors 1996

Cost comparison PET/SPECT

0

500

1,000

1,500

2,000

2,500

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Patients per day

Co

st o

f p

erfu

sio

n a

gen

t

Cost of Rb-82/day

Cost of MIBI/day

The Myth of Rb-82The Myth of Rb-82

CardioGen-82CardioGen-82®® (Rubidium (Rubidium Rb 82 Generator)Rb 82 Generator)

Rubidium-82 (Rb-82) is produced by decay of Rubidium-82 (Rb-82) is produced by decay of Strontium-82 (Sr-82)Strontium-82 (Sr-82)

75 second T½ 75 second T½ Kinetics:Kinetics:

Potassium analogPotassium analog High extraction fraction at high flow ratesHigh extraction fraction at high flow rates

Defects visualized 2-7 minutes after injectionDefects visualized 2-7 minutes after injection Same sized dose at stress & rest due to short T½ Same sized dose at stress & rest due to short T½ New generator every 28 daysNew generator every 28 days Fixed price, not unit doseFixed price, not unit dose Dose available 24 hours per day, 7 days per weekDose available 24 hours per day, 7 days per week Pharmacologic stress studiesPharmacologic stress studies

CardioGen-82CardioGen-82®® (Rubidium Rb 82 Generator)(Rubidium Rb 82 Generator) Generator replaced every 28 Generator replaced every 28

daysdays Rb-82 dose is provided Rb-82 dose is provided

within 10 minuteswithin 10 minutes Infusion System is Infusion System is

automated for the infusion automated for the infusion and patient doseand patient dose

Permits accurate dosing Permits accurate dosing with minimal operator with minimal operator interface, thus decreasing interface, thus decreasing radiation exposureradiation exposure

Contains shielding vault for Contains shielding vault for CardioGen-82CardioGen-82®® Generator Generator and waste containerand waste container

0123456

0 5 10 15 20 25

Time (s)

Rat

e (m

Ci/s

)

Dose delivery by Infusion System

Infusion pump set to deliver 60 mCi or operate for 25 sec, whichever is reached first. Maximizes bolus of Rb-82.

As generator decays, amount of dose delivered may drop. As generator decays, amount of dose delivered may drop. Consistent bolus delivery can improve count statistics near Consistent bolus delivery can improve count statistics near the end of generator life.the end of generator life.

Sample PET/CT ProtocolSample PET/CT Protocol

Protocol courtesy of Marcelo DiCarli, MDProtocol courtesy of Marcelo DiCarli, MDApproximately 30 minutesApproximately 30 minutes

scoutscout CT-transCT-trans

Rb-82Rb-8250-60 mCi50-60 mCi

70-90 sec70-90 sec90-120 sec90-120 sec

gatedgatedrestrest

pt outpt out

DipyDipy0.56 mg/kg0.56 mg/kg

scoutscoutCT-transCT-trans

70-90 sec70-90 sec90-120 sec90-120 sec

Rb-82Rb-8250-60 mCi50-60 mCi

gatedgatedstressstress

Approx 1 minApprox 1 min Approx 7 minApprox 7 min Approx 6 minApprox 6 min Approx 1 minApprox 1 min Approx 7 minApprox 7 min

Transitioning the perfusion Transitioning the perfusion marketmarket

Why Rb-82 now?Why Rb-82 now? Improved patient outcomes/lower false Improved patient outcomes/lower false

positivespositives Appointment times reduced to 30-45 minutesAppointment times reduced to 30-45 minutes Improved accuracy irrespective of body mass Improved accuracy irrespective of body mass

index, sex ect. index, sex ect. Lower radiation exposureLower radiation exposure Improve throughput and reimbursement-Improve throughput and reimbursement-

favorable economic driversfavorable economic drivers EquipmentEquipment

Diagnostic accuracy Diagnostic accuracy comparisoncomparison

Bateman etal, Diagnostic accuracy Bateman etal, Diagnostic accuracy of rest/stress ECG gated Rb-82 of rest/stress ECG gated Rb-82 myocardial perfusion PET: myocardial perfusion PET: comparison with ECG-gated Tc-99m comparison with ECG-gated Tc-99m sestamibi SPECT. J Nucl Cardiology sestamibi SPECT. J Nucl Cardiology 2006 Jan-Feb 2006 Jan-Feb

112 SPECT/PET studies matched for 112 SPECT/PET studies matched for gender, BMI, presence and extent of gender, BMI, presence and extent of ASCADASCAD

Diagnostic AccuracyDiagnostic Accuracy

PET image quality excellent 78% and PET image quality excellent 78% and 79% for rest and stress79% for rest and stress

SPECT image quality excellent 62% SPECT image quality excellent 62% and 62% for rest and stressand 62% for rest and stress

IntepretationsIntepretations Definitely normal/abnormalDefinitely normal/abnormal PETPET 96% 96% SPECTSPECT 81% 81%

Diagnostic AccuracyDiagnostic Accuracy

DiagnosDiagnostic tic accuracaccuracyy

PETPET SPECTSPECT

StenosisStenosis

(70%)(70%)89%89% 79%79%

Stenosis Stenosis (50%)(50%)

87%87% 71%71%

Men vs Men vs WomenWomen

++ --

Obese vs. Obese vs. nonobesenonobese

++ --

Patient Radiation Patient Radiation DosimetryDosimetry

IsotoIsotopepe

Effective Effective Dose Dose

EquivalentEquivalent

Per Per studystudy

TotalTotal

Rb-82Rb-82 1.6 1.6 mrem/mCimrem/mCi

50 mCi50 mCi 80 mrem80 mrem

Tc-Tc-99m 99m mibimibi

51 51 mrem/mCimrem/mCi

30 mCi30 mCi 1500 1500 mremmrem

Th-Th-201201

850 850 mrem/mCimrem/mCi

4 mCi4 mCi 3200 3200 mremmrem

CT CT mu-mu-mapmap

440 mR440 mR 1 scan1 scan 440 440 mremmrem

Copyright Dr. Mark Nathan

Acquisition Acquisition TimesTimes Acquisition times need to recognize the fast decay Acquisition times need to recognize the fast decay

time of Rb-82time of Rb-82 95% theoretical maximum of all counts will be 95% theoretical maximum of all counts will be

acquired in the first five minutesacquired in the first five minutes Acquiring an additional 60 seconds only adds 2.4% Acquiring an additional 60 seconds only adds 2.4%

more counts!more counts!

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 50 100 150 200 250 300 350

Seconds into Scan

Fra

cti

on

Fraction of ActivityRemaining

Fraction of CountsRecieved to TotalPossible

Fraction of counts tobe gained by acquiringfor 60 AdditionalSeconds

Transmission Quality Transmission Quality ControlControl

Counts, Truncation and Counts, Truncation and RegistrationRegistration

Good transmission counts, no truncation, but stress misregistration

MISREGISTRATION OFTRANSMISSION AND EMISSION DATA IS THE #1 SOURCE OF DIAGNOSTIC ARTIFACTS

Must always correct this artifact

Misregistration appear as LCx or left main diseaseMisregistration appear as LCx or left main disease

Mismatch artifactMismatch artifact

Slow CT Slow CT designed to designed to match match transmission transmission and emission and emission data setsdata sets

Minimize Minimize artifactsartifacts

CONVENTIONAL SLOW CT

Patient 1Patient 1

65yo male 280 lbs65yo male 280 lbs Chest pain syndromeChest pain syndrome Cannot exercise due to knee arthritisCannot exercise due to knee arthritis

The Power of PETThe Power of PET

Perfusion images reveal reversible Perfusion images reveal reversible perfusion defects involving the perfusion defects involving the anterior/ anterior septal and septal anterior/ anterior septal and septal walls consistent with LAD walls consistent with LAD obstructionobstruction

Coronary catherization revealed Coronary catherization revealed 85% proximal stenosis of the LAD85% proximal stenosis of the LAD

Patient 2Patient 2

45 yo female with abnormal non 45 yo female with abnormal non diagnostic GXT diagnostic GXT

Perfusion study orderedPerfusion study ordered

The Power of PETThe Power of PET

Normal perfusion patternNormal perfusion pattern Prognosis goodPrognosis good

Patient 3Patient 3

75yo female with history of PTCA of 75yo female with history of PTCA of left circumflex arteryleft circumflex artery

Now presents with recurrent Now presents with recurrent atypical chest pain syndrome and atypical chest pain syndrome and fatiguefatigue

The Power of PETThe Power of PET

Rb-82 PET revealed a reversible Rb-82 PET revealed a reversible perfusion pattern in the distribution perfusion pattern in the distribution of the left circumflex artery of the left circumflex artery consistent with re stenosis of the consistent with re stenosis of the arteryartery

Advantages of PETAdvantages of PET

Faster study Faster study More accurateMore accurate Attenuation correctionAttenuation correction Health care cost savingsHealth care cost savings

PET perfusion imagingPET perfusion imagingHigh diagnostic accuracy regardless of patient status

Shorter acquisition times

Higher insurance reimbursement

Lower radiation exposure

Value for the patient

Value for the practice