Myocardial perfusion SPECT offers 5-year warranty

The short-term prognostic benefit of myocardial perfusion scintography (MPS) is well established, and the technique also delivers long-term value up to five years after initial imaging, according to a study in the Journal of Nuclear Cardiology.

The review written by Jane A. Simonsen, MD, from the department of nuclear medicine at Odense University Hospital in Denmark, and colleagues, found few deaths and other major cardiac events after MPS evaluation of coronary artery disease.

The review included 4,850 MPS imaging studies from 2002 to 2007 for patients referred for suspected or known ischemic heart disease. A total of 1,327 normal MPS studies were followed up to 10 years after MPS was completed. The average was just over 6 years after initial study. Single photon emission computed tomography (SPECT) and Tc-99m sestamibi were used in all cases. Subsequent risk of cardiac events varied across patients according to factors such as gender and the presence of other conditions including diabetes. Men were found to be at increased risk compared to women.

“Men with normal MPS had significantly more events than women,” wrote Simonsen, et al. “Indeed, their risk equated that of diabetic patients, whereas women had a risk similar to non-diabetic patients.”

Diabetic patients were seen to have more cardiac risk after three years and may need to be retested sooner. The authors recommended a general warranty period for MPS’ best prognostic benefit.

“Of particular interest, patients with known CAD, but no prior revascularization, constituted a subset with the highest and fastest growing mortality risk, reaching 6 percent in 4 years,” wrote the researchers. “Another novel finding was that events occurred relatively late, suggesting a general warranty period of five years, but somewhat shorter in risk groups.”