JACC: New SPECT agent could detect patients with acute coronary syndrome
The addition of Molecular Insight Pharmaceuticals’ Zemiva (Iodofiltic acid I 123) imaging data to initially available clinical information contributes to the early diagnosis and evaluation of myocardial ischemia and acute coronary syndrome (ACS), according to a Phase 2 clinical trial published in the July 20 edition of the Journal of the American College of Cardiology.

Zemiva is an iodine-123 labeled fatty acid analog delivered by intravenous injection which is retained in heart cells that have a healthy blood supply but not retained in areas of the heart that have suffered an ischemic event.

"Our research suggests that Zemiva has promise to be an important tool in the diagnosis of acute coronary syndrome, offering improved sensitivity that may allow physicians to determine the presence or absence of ACS earlier in the diagnostic workup," said the study's principal investigator James E. Udelson, MD, chief, division of cardiology and director of nuclear cardiology at Tufts Medical Center in Boston.

During the open-label trial, the safety and efficacy of Zemiva were evaluated in 507 patients with symptoms suggestive of ACS at emergency departments at 50 hospitals in North America. Patients received 5 mCi Zemiva within 30 hours of symptom cessation.

The addition of results from Zemiva SPECT imaging demonstrated an improvement in sensitivity (from 43 to 81 percent), positive predictive value (from 41 to 58 percent) and negative predictive value (from 62 to 83 percent) over the initial clinical information alone for ACS within 30 hours of cessation of chest pain symptoms, while maintaining specificity. The ability to image ischemic abnormalities even after symptoms resolve is a unique feature of the agent, noted Udelson and colleagues.

Out of the 507 patients, 21.5 percent reported adverse events. Most adverse events reported in the trial were judged mild in severity by the investigators; the most common event was headache (3.9 percent). There were serious adverse events reported in 27 patients including four deaths during the 30-day follow-up period and none of these was considered by the investigators to be drug-related.

"The addition of Zemiva data to the initially available clinical information adds incremental value toward the early diagnosis of ACS, potentially allowing determination of the presence or absence of ACS to be made earlier in the evaluation process," concluded Udelson and colleagues.