Stress myocardial perfusion imaging (MPI) to evaluate the lack of blood flow in the heart has been substantiated as a method to help physicians assess the treatment needs of heart attack survivors and the risk of a second heart attack.
Results from the Adenosine Sestamibi Post-Infarction Evaluation (INSPIRE) trial led by Baylor College of Medicine (BCM) in Houston was presented at last week's 53rd Annual Scientific Session of the American College of Cardiology (ACC).
"Because we are able to test patients so early after a heart attack, this study revealed that MPI can help physicians assess the likelihood of a follow-up heart attack or readmission for cardiac reasons and more precisely guide subsequent treatment from medical therapy to coronary revascularization," noted John Mahmarian, MD, medical director of the Nuclear Cardiology Laboratories Methodist DeBakey Heart Center and the Baylor Heart Clinic.
Mahmarian described the study as a "significant breakthrough, because the current perception is that a heart attack sufferer needs to undergo coronary angiography, or surgical procedure, to evaluate the damage of the heart. This study demonstrated that patients found to be at low risk by MPI also are at low risk of a second heart attack and therefore unlikely to benefit from coronary angiography."
The multicenter, randomized trial evaluated 728 patients worldwide whose post-heart attack condition had stabilized. All patients underwent a baseline MPI, using adenosine and sestamibi within 10 days of a heart attack, to assess the extent of jeopardized heart muscle and blood pumping ability, also known as left ventricular ejection fraction (LVEF).
Adenosine is a commonly used substitute for patients who cannot perform exercise stress testing and can safely be delivered intravenously even shortly after a heart attack. Sestamibi is a cardiac imaging agent which enables physicians to simultaneously evaluate heart function and blood flow to the heart muscle.