A combination of ticagrelor and aspirin improved the saphenous vein graft (SVG) patency rate 12 months after coronary artery bypass grafting (CABG) compared with aspirin alone, according to results of the DACAB* trial from China.

“What [these results] show is that the combined dual antiplatelet strategy is associated with better graft patency,” said Professor Sidney Smith from the University of North Carolina, US, and past president of the American Heart Association (AHA) who discussed the findings at AHA 2017.

Researchers of the prospective, open-label, multicentre DACAB trial, led by Professor Zhao Qiang from Ruijin Hospital in Shanghai, China, sought to compare the efficacy and safety of a ticagrelor-aspirin combination or ticagrelor monotherapy vs aspirin monotherapy on SVG patency 1 year following CABG.

Five hundred patients scheduled to undergo elective, isolated CABG were randomized to receive either ticagrelor (90 mg BID) plus aspirin (100 mg QD; n=168, mean age 63.5 years, 79.8 percent male), ticagrelor alone (90 mg BID; n=166, mean age 63.3 years, 80.7 percent male), or aspirin alone (100 mg QD; n=166, mean age 64 years, 84.9 percent male) for 12 months, with the study drugs initiated within 24 hours following CABG procedure.

The SVG patency rate at 12 months was highest in patients on aspirin plus ticagrelor (88.7 percent), followed by ticagrelor alone (82.8 percent) and aspirin alone (76.5 percent). [AHA 2017, abstract LBS.01]

The patency rate with ticagrelor plus aspirin differed by 12.2 percent compared with aspirin alone (p=0.0006), while the patency rate was similar between ticagrelor and aspirin monotherapy (6.3 percent; p=0.0962).

The incidence of major adverse cardiac events (comprising cardiovascular death, myocardial infarction, and stroke) was numerically fewer among patients on ticagrelor plus aspirin (n=3) compared with ticagrelor or aspirin monotherapy (n=4 and 9, respectively).

There was a higher incidence of non-CABG-related bleeding among patients in the combination group (n=51) compared with ticagrelor (n=20) or aspirin monotherapy (n=15), but there were few instances of both CABG-related and non-related major bleeding (n=3, 2, and 0 in patients on ticagrelor plus aspirin, ticagrelor monotherapy, and aspirin monotherapy, respectively).

“We have here, emerging, a very nice study, a very well-done study that suggests graft patency as measured at the end of one year is better [with ticagrelor plus aspirin]. The big question is, does this make a difference in outcomes?” asked Smith.

“[I] think we’re going to continue to be discussing this very interesting problem for at least a few years to come,” he said.

Study discussant Professor John H Alexander from Duke University School of Medicine, Durham, North Carolina, US, agreed.

“[While] the effect of ticagrelor on SVG patency from DACAB is compelling … [it] will be insufficient to drive changes in practice,” said Alexander.

“Clinical trials of [dual antiplatelet therapy] post-CABG with clinical outcomes [are] needed,” he said, highlighting that the study was underpowered to assess major bleeding incidence and that the association between SVG failure and outcomes is yet to be established.

“Ticagrelor may [also] have benefits beyond SVG patency,” he said.