Findings From OCTAMI Study Published

June 25, 2010—The OCTAMI (Optical Coherence Tomography [OCT] in Acute Myocardial Infarction) study of strut coverage and vessel wall response to zotarolimus-eluting stents (ZES) and bare-metal stents (BMS) implanted in patients with ST-segment elevation myocardial infarction (STEMI) was published in the Journal of the American College of Cardiology: Cardiovascular Interventions (2010;3:680–687).

According to the investigators, whereas sirolimus- and paclitaxel-eluting stents implanted in STEMI have been associated with delayed healing and incomplete strut coverage, ZES are associated with a more complete and uniform strut coverage in stable patients; however, it is not known if this holds true also after STEMI.

Using OCT, the investigators assessed the proportion of uncovered struts at 6-month follow-up in the Endeavor ZES (Medtronic, Inc., Minneapolis, MN) and an identical BMS implanted in patients with STEMI. Forty-four patients with STEMI who underwent primary PCI were randomized to ZES or BMS (3:1 randomization). Angiographic, intravascular ultrasound, and OCT follow-up was conducted at 6 months and clinical follow-up at 1 year. All images were analyzed by an independent core laboratory that was blind to stent assignments.

The investigators reported that there were no differences between ZES and BMS in percentage of uncovered struts (median, 0% [interquartile range (IQR), 0%–1.78%] vs 1.98% [IQR, 0.21%–7.33%]; P = .13), maximum length of uncovered segments (0.00 [IQR, 0.00–1.19] mm vs 1.38 [IQR, 0.65–3.3] mm; P = .1), percentage of malapposed struts (0% [IQR: 0.00%–0.23%] vs 0.15% [IQR, 0%–5.81%]; P = .16), and maximum length of malapposed segments (0.00 [IQR, 0.00–0.67] mm vs 0.33 [IQR, 0.00–2.55] mm; P = .2). Neointimal response was similar between ZES and BMS (332 [IQR, 240–429] µm vs 186 [IQR, 136–348] µm; P = .99) and evenly distributed. No late acquired malapposition was observed in either group. There were no deaths, myocardial infarctions, or stent thromboses at 1 year.

In conclusion, the investigators stated that this OCT study found no difference in strut coverage and similar vessel response to ZES, when compared with identical BMS, implanted during primary PCI in STEMI patients.