In patients with STEMI treated with primary percutaneous coronary intervention, undergoing PCI for chronic total occlusion within a week of STEMI appears to be safe and feasible, according to results from the EXPLORE trial presented at the annual TCT Scientific Symposium.
However, PCI for CTO does not appear to improve left ventricular ejection fraction or left ventricular diastolic volume at 4 months.
In the multicenter, randomized, prospective, two-arm trial, Jose P.S. Henriques, MD, of the University of Amsterdam, and colleagues evaluated patients with STEMI treated with primary PCI (pPCI) who had a noninfarct-related CTO.
Participants were randomly assigned at a 1:1 ratio to treatment with PCI for CTO (n = 148) within 7 days of STEMI or no CTO intervention after STEMI (n = 154). The study’s two primary endpoints, which were assessed at 4 months on MRI, were LVEF and left ventricular end diastolic function (LVEDF). There was an even distribution of baseline characteristics among the two cohorts.
“However, I’d like to draw your attention to the high degree of triple vessel disease and multiple CTOs in this patient cohort,” Henriques said.
In the CTO-PCI group, there were 13 patients (9%) with multiple CTOs, and 22 (14%) in the no CTO-PCI group. The (mean, SD) pre-pPCI MI SYNTAX score was 29 ± 8 in the CTO-PCI group, and 29 ± 10 in the no CTO-PCI group.
In terms of the study’s primary endpoints, the researchers found no significant difference in 4-month percent LVEF (CTO-PCI 44.1 [12.2] vs. no CTO-PCI, 44.8 [11.9]; difference, -0.8; 95% CI, -3.6 to 2.1) or LVEDF in mL (CTO-PCI, 215.6 [62.5] vs. no CTO-PCI, 212.8 [60.3]; difference, 2.8; 95% CI, -11.6 to 17.2).
“However, when looking at a subgroup analysis of the first primary outcome, LVEF, there was a clear and statistically significant difference in patients with CTO of the [left anterior descending coronary artery] in favor of undergoing CTO-PCI,” Henriques said. “This was not seen in the end diastolic volumes; it did not reach statistical significance for this endpoint, but did show a trend.”
In terms of major adverse CV events at 4 months, the rate was 5.4% in the CTO-PCI group and 2.6% in the no CTO-PCI group (P = .212).
“In short, CTO-PCI within one week after primary PCI is feasible and safe, but not associated with better ejection fraction or lower diastolic volume at 4 months,” Henriques said.
“However, there is a clear signal in the patients with chronic total occlusion of the LAD because there was a highly statistically significant difference in ejection fraction in favor of this group … [and] we believe that additional PCI of a CTO located in the LAD may improve LVEF and potentially improve clinical outcome during follow-up.” - by Jennifer Byrne
Henriques JPS. The Evaluating Xience and left ventricular function in PCI on occlusions after STEMI (EXPLORE) trial. Presented at: TCT Scientific Symposium; Oct. 11-15, 2015; San Francisco.
Disclosure: Henriques reports receiving grant/research support from Abbott Vascular, Abiomed Inc., Biotronik and B. Braun.