Quantitation in Nuclear Cardiology Influence on Management Decision : Revascularization vs Medical Therapy. João V.

Transcription

1 Quantitation in Nuclear Cardiology Influence on Management Decision : Revascularization vs Medical Therapy João V. Vitola Curitiba joaovitola@quantamn.com.br DISCLOSURES Honorarium Research / Advisor, Expert Services and Conferences in Nuclear Cardiology BMS, CVT, Astellas, Lantheus, PPGx, International Atomic Energy Agency Royalties Publications in Nuclear Cardiology Springer-Verlag-Nuclear Cardiology and Correlative Imaging: a teaching file, NY, 2004 Lippincott Williams & Wilkins, - Nuclear Medicine teaching File, 2009

2 Sequence to follow and discuss Clinical cases to ilustrate the relatioship between ischemia and sudden death How to segment the LV to quantify extent and severity of ischemia? Quantitation based on perfusion scores (SSS, SDS, SRS) and relation to risk LV volumes, LVEF and risk Quantitation based on % of LV ischemic and event risk Use of quantitation as a measure of success of treatment in clinical trials

3 51 yo, HTN, obese DM, Fam Hx CAD NO HISTORY OF CAD Episodes of chest pain at rest and exercise Referred for outpatient MIBI

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9 NSR after 3 shocks cath 3 vessels.. Tight lesions surgery! How much ischemia? Very significant ischemia ~ enough to induce ST elevation and VTach

10 Middle Age Women undergoing investigation of suspected CAD Female, 54 yo, obese, atypical chest pain, referred for MIBI NO HISTORY OF CAD 3 min AFTER low workload exercise on the treadmill Ischemia Induced Cardiac Arrest Would probably be fatal outside hospital/clinic OUTCOME Successful defibrilation, Cath (3 V disease) Surgical revascularization, ALIVE AND WELL How much ischemia?

11 CHALLENGES TO FIGHT CVD MORTALITY Sudden death is frequently the first manifestation of CAD

12 CHALLENGES TO FIGHT CVD MORTALITY 50% of AMI patients die before arriving to the hospital

13 Mechanisms of death in CAD Atherosclerosis : obstructive disease severe ischemia ventricular arrythmias specially if LV dysfunction Atherosclerosis : unstable plaques

14 Changing the paradigm in cardiac risk stratification From : Anatomic and static (Lumen) concept (angio) To : Physiological and Dynamic (FFR, CVR, IVUS, SPECT) From: What % lumen obstruction? To : How much myocardium at risk? What % myocardium severely ischemic

15 What results to expect in a nuclear cardiology Laboratory? Patterns of Perfusion Abnormality Anormalidades de Perfusao % 20.41% 4.54% 6.20% Normal Isquemia Fibrose F+I Seqüência Seqüência % 20.41% 4.54% 6.20% Seqüência1 Seqüência2 Average Abnormal Rate 35.4% Vitola JV (QUANTA database)

16 Frequency of Abnormal SPECT Depending on Each Variable Above Average Athletes Low Duke Exercise Test Female Gender Phy Active Mean Abnormal Rate Sedentary Cholesterol Male Gender Diabetes Typical Pain Dipyridamole Known CAD Hx PCI Hx CABG High Duke 6.00% 22.60% 26.90% 30.50% 32.80% 35.40% 38.30% 39.20% 39.80% 52.30% 53.20% 60.30% 63.60% 64% 75% 76% Vitola JV (QUANTA database, n > )

17 QUANTIFICATION OF ISCHEMIA NECESSARY TO GUIDE MANAGEMENT Test result Normal vs Abnormal is not enough Magnitude of ischemia relates to prognosis Small vs large, discrete vs severe Low risk vs high risk ischemia

18 Extent/Severity Ischemia Predicting Death Risk* Source: Klocke et al. J Am Coll Cardiol Extent/Severity of Perfusion Defects *Adjusted or unadjusted

19 Management based on degree of Ischemia Who Needs Revascularization? Nuclear is powerful to estimate risk Source: Klocke et al. J Am Coll Cardiol 2003.

20 Quantification in Nuclear Cardiology Scores Severe LCX Moderate RCA Extent: number of segments 1 to 17 Severity: 0 normal 1 mild 2 mod 3 severe 4 absent

21 What is the SSS? Segment Severity SSS 32

22 Risco baseado na quantificação - SPECT 5 4 Cardiac Death MI , Normal < 4 Mildly Moderately Severely > 13 Abnormal Abnormal Abnormal Summed Stress Perfusion Score Hachamovitch Circ 1998;97:

23 What to Report in This Study in a descriptive way?

24 What to Report in This Study? Sestamibi, exercise, Bruce, 134 bpm, 6.5 minutes, Severe, Extensive, AS + Apical, Proximal LAD territory, Hipokinesia from stress, stunning-clear MESSAGE of HIGH RISK

25 LV function quantitation parameters and risk estimations

26 AMI 6 years in the past, treated with primary PTCA Adenoex, 5 min on Bruce, peak HR 93 spm (on meds), denied chest pain.

27 AKINESIA REMODELED LV LVEF 25 % (nl > 50%) EDV 235 ml (nl 101 ml) ESV 176 ml (nl 44 ml)

28 Hibernation Stunning Scar from prior MI 63 yo man, physician, had sudden death while playing tennis MPI 24 months prior to his death

29 % Ischemic Myocardium Total Perfusion Deficit (TPD) TPD: Quantitative Measure of Defect Extent & Severity % Ischemic Myocardium: (Stress TPD-Rest TPD) < 5%: Minimal ( No Ischemia ) 5.0%-9.9%: Mild 10%: Moderate-to-Severe Defect Severity Significant Reduction in Ischemia: 5% Reduction in Ischemic Myocardium* Defect Extent TPD Lower Nl Limit Source: Slomka et al. J Nucl Cardiol 2005;12:66-77

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31 Risk of Cardiac Death & Ischemic Burden Post-SPECT Therapeutic Decisions log Hazard Ratio ,627 patients 146 Cardiac death 492 All cause mortality * Medical therapy * Revascularization 1 0 *P< % 25% 32.5% 50% Source: Hachamovitch et al. Circulation. 2003; % Total Myocardium Ischemic

32 COURAGE - Randomization based on anatomy NOT ischemia Only Sub study used nuclear quantification (n=314) Help us understand why PCI did no reduce mortality in the entire study but only subgroups PCI + OMT (n=159) OMT (n=155) 8.2% 5.5% 8.6% 8.1% (4.7%-6.3%) (6.9%-9.4%) Shaw L et al, circ, 2008

33 Sub study COURAGE nuclear p=0.001 Death or MI Rate (%) 16.2% 32.4% (n=68) (n=37)

34 ISCHEMIA Trial International Study of Comparative Health Effectiveness with Medical and Invasive Approaches NIH funding 97 millhões US PIs David Maron, Nashville Judith Hochman, NYC 8,000 stable CAD patients 3-6 yr. F/U for events* *CV Death, MI, hosp for ACS, CHF

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36 Ischemia trial, perhaps results by 2018 ~ 2020? How would you manage the following patients in 2012?

37 Male, 53 yo Atypical pain stress Calcium score: 10 / Duke Intermediate Habibian R, Delbeke D, Martin W, Sandler M, Vitola JV Cardiovascular Imaging, in Nuclear Medicine Teaching File, 2009 Cortes Tomográficos-Referência Eixo Curto Eixo Longo Vertical Eixo Longo Horizontal

38 Severe ischemia > 10% of LV Post 1 stent LAD Risk > 3%/ y Risk< 1%/y Habibian R, Delbeke D, Martin W, Sandler M, Vitola JV Cardiovascular Imaging, in Nuclear Medicine Teaching File, 2009

39 Male 61 yo Dispnea on exertion, Atypical Pain > 10% severe ischemia Cortes Tomográficos-Referência Eixo Curto Eixo Longo Vertical Eixo Longo Horizontal Habibian R, Delbeke D, Martin W, Sandler M, Vitola JV Cardiovascular Imaging, in Nuclear Medicine Teaching File, 2009

40 Post CABG 0 % ischemia Habibian R, Delbeke D, Martin W, Sandler M, Vitola JV Cardiovascular Imaging, in Nuclear Medicine Teaching File, 2009

41 CONCLUSIONS Sudden death is frequently the first manifestation of CAD NUCLEAR Imaging is useful to provide quantification of ischemia and risk assessment Define high risk subgroups who will benefit from revascularization Define low risk subgroups who will benefit from prevention and medical therapy ISCHEMIA trial will be an important prospective randomized trial based on % ischemia

42 Thank you CURITIBA