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An Initial Strategy of Intensive Medical Therapy is Comparable to that of Coronary Revascularization for Suppression of Scintigraphic Ischemia in High Risk but Stable Survivors of Acute Myocardial Infarction
John J. Mahmarian, MD, Habib A. Dakik, MD; Neil G. Filipchuk, MD, Leslee J. Shaw, PhD, Sherif S. Iskander, MD, Terrence D. Ruddy, MD, Felix Keng, MD, Milena J. Henzlova, MD, Adel Allam, MD, Lemuel A. Moye, MD, PhD, and Craig M. Pratt, MD for the ADENOSINE SESTAMIBI SPECT POST-INFARCTION EVALUATION (INSPIRE) Investigators
from The Methodist DeBakey Heart Center, Department of Cardiology, The Methodist Hospital, Houston, Texas; American University of Beirut, Beirut, Lebanon; University of Calgary, Calgary, Alberta, Canada; Cedars-Sinai Medical Center, Los Angeles, California; Cardiovascular Associates of East Texas, Tyler, Texas; University of Ottawa Heart Institute, Ottawa, Ontario, Canada; National Heart Centre , Singapore, Singapore; Mount Sinai Medical Center, New York, New York; Al-Azhar University, Cairo, Egypt, University of Texas School of Public Health, Houston, Texas
OBJECTIVES To determine the relative benefit of intensive medical therapy as compared to coronary revascularization for suppressing scintigraphic ischemia.
BACKGROUND Although medical therapies can reduce myocardial ischemia and improve patient survival following acute myocardial infarction, the relative benefit of medical therapy versus coronary revascularization for reducing ischemia is unknown.
METHODS Prospective, randomized trial in 205 stable survivors of acute myocardial infarction to define the relative efficacy of an intensive medical therapy strategy versus coronary revascularization for suppressing scintigraphic ischemia as assessed by serial gated adenosine Tc-99m sestamibi myocardial perfusion tomography. All patients at baseline had large total (>20%) and ischemic (>10%) adenosine-induced left ventricular perfusion defects and an ejection fraction >35%. Imaging was performed 1-10 days of hospital admission and repeated in an identical fashion following optimization of therapy. Patients randomized to either strategy had similar baseline demographic and scintigraphic characteristics. Both intensive medical therapy and coronary revascularization induced significant but comparable reductions in total (-16.2+/-10% vs -17.8+/-12, p=NS) and ischemic (-15+/-9% vs -16.2+/-9%, p=NS) perfusion defect sizes, respectively. Likewise, a similar percentage of patients randomized to medical therapy versus coronary revascularization had suppression of adenosine-induced ischemia (80% vs 81%, p=NS).
CONCLUSIONS Sequential adenosine sestamibi myocardial perfusion tomography can effectively monitor changes in scintigraphic ischemia following either anti-ischemic medical or coronary revascularization therapy. A strategy of intensive medical therapy is comparable to coronary revascularization for suppressing ischemia in stable patients after acute infarction who have preserved LV function.
A Multinational Study to Establish the Value of Early Adenosine Technetium-99m Sestamibi Myocardial Perfusion Imaging in Identifying a Low-Risk Group for Early Hospital Discharge Following Acute Myocardial Infarction
John J. Mahmarian, MD, FACC, Leslee J. Shaw, PhD, Neil G. Filipchuk, MD, Habib A. Dakik, MD, Sherif S. Iskander, MD, Terrence D. Ruddy, MD, Milena J. Henzlova, MD, Felix Keng, MD, Adel Allam, MD, Lemuel A. Moye, MD, PhD, and Craig M. Pratt, MD, FACC, for the ADENOSINE SESTAMIBI SPECT POSTINFARCTION EVALUATION (INSPIRE) Investigators
from The Methodist DeBakey Heart Center, Department of Cardiology, The Methodist Hospital, Houston, Texas; Cedars-Sinai Medical Center, Los Angeles, California; University of Calgary, Calgary, Alberta, Canada; American University of Beirut, Beirut, Lebanon; Cardiovascular Associates of East Texas, Tyler, Texas; University of Ottawa Heart Institute, Ottawa, Ontario, Canada; Mount Sinai Medical Center, New York, New York; National Heart Centre, Singapore, Singapore; Al-Azhar University, Cairo, Egypt; University of Texas School of Public Health, Houston, Texas
OBJECTIVES To determine whether gated adenosine Tc-99m sestamibi myocardial perfusion tomography (ADSPECT) could accurately define risk and thereby guide therapeutic decision-making in stable survivors of acute myocardial infarction (AMI).
BACKGROUND Controversy continues as to the role of noninvasive stress imaging in stratifying risk early after AMI.
METHODS The Adenosine Sestamibi SPECT Post Infarction Evaluation (INSPIRE) is a prospective, multicenter trial which enrolled 728 clinically stable survivors of AMI who had gated ADSPECT within 10 days of hospital admission and subsequent 1 year follow-up. Event rates were assessed within prospectively defined INSPIRE risk groups based on the adenosine-induced left ventricular perfusion defect size, extent of ischemia, and ejection fraction.
RESULTS Total cardiac events and death and reinfarction significantly increased within each INSPIRE risk group from low (5.4%, 1.8%), to intermediate (14%, 9.2%), to high (18.6%, 11.6%) (p less than 0.01). Event rates at 1 year were lowest in patients with the smallest perfusion defects but progressively increased when defect size exceeded 20% (p less than 0.0001). The perfusion results significantly improved risk stratification beyond that provided by clinical and ejection fraction variables. The low risk INSPIRE group, comprising one-third of all enrolled patients, had a shorter hospital stay with lower associated costs as compared to the higher risk groups (p less than 0.001).
CONCLUSIONS Gated ADSPECT performed early after AMI can accurately identify a sizeable low risk group who have a less than 2% death and reinfarction rate at 1 year. Identifying these low risk patients for early hospital discharge may improve utilization of healthcare resources at considerable cost savings.
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