1. Aqueous Oxygen Therapy Improves ST –Segment Resolution in Anterior Myocardial Infarction AMIHOT Phase II Clinical Study AMIHOT Phase II Clinical Study J. L. Martin, B.S. Lindsay, P.V. Oemrwasingh, D.A. Atsma, M.W. Krucoff, S.R. Dixon, A.L. Bartorelli, W.W. O’Neill, for the AMIHOT Investigators Main Line Health TCT 2004 Washington DC, September 27- October 1, 2004

2. Solution of saline and hyperbaric levels (pO2~30,000 mmHg) of dissolved oxygen (1 ml O 2 /ml saline) Remarkable stability (no bubble formation) despite high level of O 2 saturation due to the controlled delivery from high pressure (40 atm) to ambient blood AO is mixed with the patient’s arterial blood at a ratio of 25 parts blood to 1 part AO (pO 2 >760 mmHg), and carried to the myocardial tissue via the plasma Supersaturated Oxygen Aqueous Oxygen (AO)

3. Infarct Size after AO Therapy Pig Model AORP= Treatment group with 90’ AO hyperoxemic perfusion Auto RP= Control group with normoxemic reperfusion Spears et al. 1999 AO RP Auto RP Area of necrosis Area of risk * p< 0.01 (vs. Auto RP) % Left Ventricle (n=6) (n=6)

4. *p<0.01 vs.baseline, † p=0.01 Dixon SR. J Am Coll Cardiol 2002;39:387-92 TherOx Pilot Study LV Function Recovery (WMSI)

5. 28% mean relative improvement 2.5% mean relative improvement Centro Cardiologico Monzino, Milan, Italy AO Treated vs. Controls Bartorelli A. TCT 2002 OYSTER-AMI AO in Anterior AMI

6. Increasing O 2 diffusion distance 3 to 4 times and O 2 penetration into ischemic myocardium Increasing O 2 diffusion distance 3 to 4 times and O 2 penetration into ischemic myocardium Reducing interstitial/endothelial edema Reducing interstitial/endothelial edema Reducing leukocyte activation (decreased myeloperoxidase levels) Reducing leukocyte activation (decreased myeloperoxidase levels) Improving capillary blood flow in the IRA microcirculation Improving capillary blood flow in the IRA microcirculation AO Therapy Benefits  AO is believed to salvage myocardium by

7. To evaluate –the safety of intra-coronary hyperoxemic therapy after primary PCI for AMI –the efficacy of hyperoxemic reperfusion to enhance ST-segment elevation recovery, improve convalescent left ventricular function and reduce infarct size AMIHOT AMIHOT Study Objective

8. Principal Investigator: William W. O’Neill, MD Sponsor: TherOx® Inc., Irvine, California Core Laboratories -Echo - Mayo Clinic, (Jae Oh, MD) -Nuclear- Mayo Clinic, (Raymond J. Gibbons, MD) -ECG - DCRI, (Mitchell W. Krucoff, MD) DSMB: Magnus Ohman, MD (Chairman) Study Organization Study Organization

9. Top Ten Enrollers Jack L. Martin MD, Main Line Health System Pranobe V. Oemrawsingh MD, Douwe Atsma, MD Leiden University Medical Center William W. O’Neill MD, Simon R. Dixon MD, William Beaumont Hospital Michael Chang, MD, William Marquardt MD, Mercy General Hospital Shukri David, MD, Providence Hospital Antonio L. Bartorelli, MD, Daniela Trabattoni, MD, Centro Cardiologico Monzino James B. Hermiller, MD, Saint Vincent Hospital Peter S. Fail, MD, Terrebonne General Hospital Rimvydas Plenys, MD, Saint Agnes Medical Center Habib Samady, MD, Michael Ragosta, MD, University Of Virginia Health System

10. ST-Monitor 24-hours Normoxemic Reperfusion (Standard Therapy) AMI  24-hrs (Primary or Rescue) n=269 Successful PCI Hyperoxemic Reperfusion with AO for 90-minutes SPECT Scan 14-days Contrast Echo 1 month Contrast Echo 3 months Anterior MI or Inferior MI with anterior ST  Initial TIMI flow  2 AMIHOT AMIHOT Trial Algorithm Major exclusion: Cardiogenic shock Need for IABP Systemic pO 2 <80mmHg Enrollment in 20 US and European sites Jan 2002 – Dec 2003

11. AMIHOT Trial Endpoints  Primary Safety Endpoint - Composite of death, reinfarction, TVR and stroke at 30 days  Primary Efficacy Endpoints - Regional wall motion score index (WMSI) at 3 months (16-segment model*) (16-segment model*) - Infarct size at 14-days (SPECT imaging) - Infarct size at 14-days (SPECT imaging) - ST-Segment resolution (continuous ST-monitoring) - ST-Segment resolution (continuous ST-monitoring) *Schiller et al. J Am Soc Echo1989; 2: 358-367

12. 6.235.45Time to Reperfusion (hours) 1.88 11% 2.23 16% Door to Balloon (hours) Rescue PCI 1%1.5%Previous CABG 60%56%Anterior MI 53%49%Hypertension 12%7%Previous PCI 13%10%Previous MI 43%42%Smoker 49%41%Dyslipidemia 13%11%Diabetes 27% Female 6060.0Age (yrs) AO (n=134)Control (n=135) AMIHOT Trial Clinical Characteristics

13. 4%8% 2 100% Stent 90%84%IIb/IIIa inhibitor Final TIMI flow grade 0% 3 60%56% LAD 31%36% RCA 8% 1% 6% 2% Circumflex Other Initial TIMI flow grade 87%90% 0/1 13%10% 2 96%92% 3 0% 0/1 Infarct related artery AO (n=134)Control (n=135) AMIHOT Trial Angiographic Characteristics

14. AO system & Delivery

15. 15 AMIHOT Trial - 30-day MACE 3.0 1.5 2.2 1.5 0.7 1.5 6.0 4.4 DeathRe-InfarctTVRStrokeComposite Primary Safety Endpoint Treat (n=134)Control (n=135) % p=ns

16. AMIHOT ST-Elevation Reduction in AO Therapy vs. Controls All Patients (Area under the Curve) t (hr) 3456 1000 1200 1400 1600 1800 2000 2200 Tx (n = 106) Ctr (n = 116) p = ns at 3, 4, 6 hrs Area Under the Curve Mean ST-elevation

17. AMIHOT ST-Elevation Reduction in AO Therapy vs. Controls Anterior Patients (Area under the Curve) t (hr) 3456 1000 1500 2000 2500 3000 3500 Tx (n = 65) Ctr (n = 64) p = 0.04 @ 3 hrs p = 0.03 @ 4 hrs p = 0.02 @ 6 hrs Area Under the Curve Mean ST-elevation

18. Regional Wall Motion & Infarct Size Infarct Size Regional Wall Motion Primary Endpoints P=0.16 N=101N=119 P=NS N=103N=112

19. Time to Reperfusion <6 hrs All Patients P=0.05 N=84N=69 Infarct Size Regional Wall Motion N=82N=69 P=0.04

20. P=0.049P=0.01 Anterior MI Patients N=49N=42N=61N=68

21. Anterior MI Group P=NS P=NS Overview of AO Treatment Effect Early Indicators of Improved Microcirculation Later Indicators of Improved Cardiac Function P=0.04 P=0.049 P=0.018

22. gg AMIHOT Trial Conclusions Hyperoxemic reperfusion with Aqueous Oxygen is safe and well tolerated after primary PCI for AMI ST segment resolution is significantly better in the anterior MI group with a favorable trend in the entire cohort Infarct size as determined by Sestamibi Scan shows a favorable trend in the entire cohort with a significant reduction in infarct size in patients treated within 6 hours of symptom onset

23. AMIHOT Trial Conclusions - continued Early indicators of relief of myocardial ischemia (i.e ST- Segment resolution) lead to later functional recovery (i.e. RWMSI improvement at 3 months). The AMIHOT study is the first adjunctive device study to demonstrate significance in multiple endpoints in AMI.