SAN DIEGO– The antithrombin drug bivalirudin received a boost, compared with unfractionated heparin, as the safer drug for preventing ischemic events in patients with acute coronary syndrome undergoing percutaneous coronary intervention in results from a multicenter, randomized trial with more than 7,000 patients.
Although the two primary endpoints from this head-to-head comparison showed no statistically significant differences between the two agents, prespecified secondary endpoints showed that treatment with bivalirudin (Angiomax) during percutaneous coronary intervention (PCI) resulted in significantly fewer deaths after 30 days and significantly fewer major bleeding events, compared with unfractionated heparin (UFH), Dr. Marco Valgimigli said at the annual meeting of the American College of Cardiology. Participating physicians administered the UFH with an antiplatelet glycoprotein IIb/IIIa inhibitor (at the operator’s discretion) 26% of the time.
In the antithrombin-randomization analysis of the MATRIX (Minimizing Adverse Hemorrhagic Events by Transradial Access Site and Systemic Implementation of Angiox) trial, which included 7,213 of the 8,404 acute coronary syndrome patients enrolled in MATRIX, treatment with bivalirudin or UFH led to similar combined rates of all-cause death, myocardial infarction, or stroke, as well as similar rates of death, MI, stroke, and major bleeds, said Dr. Valgimigli, an interventional cardiologist at Erasmus University Medical Center in Rotterdam, the Netherlands. A separate analysis of MATRIX focused on PCI outcomes with transradial vs. transfemoral access (Lancet 2015 [doi:10.1016/S0140-6736(15)60292-6]).
But treatment with bivalirudin cut the 30-day rate of all-cause death by an absolute 0.6%, driven by a concurrent cut in cardiovascular death by 0.7%, which meant that treatment with bivalirudin reduced 30-day cardiovascular deaths by one event for about every 150 patients treated, compared with patients treated with UFH, he reported. Another secondary-endpoint analysis showed that bivalirudin treatment cut the 30-day rate of major bleeding events by an absolute 1.1%, but also increased the rate of definite stent thrombosis by an absolute 0.4%, both statistically significant differences. These important differences got diluted in the primary, combined endpoints by a relatively large number of periprocedural MIs that occurred at an equal rate in both arms of the study, Dr. Valgimigli said.
The antithrombin results from MATRIX followed mixed results in several prior comparisons of bivalirudin and UFH for percutaneous coronary intervention acute coronary syndrome patients (JAMA 2015 [doi:10.1001/jama.2015.2345]). A year ago, results from the HEAT-PCI (Unfractionated Heparin Versus Bivalirudin in Primary Percutaneous Coronary Intervention) trial (Lancet 2014;384:1849-58), which enrolled 1,829 ST-elevation MI patients at one U.K. center, showed a significant reduction in ischemic events and no increased bleeding in patients treated with UFH, compared with those who received bivalirudin, a finding that experts now say seemed to lead to increased use of UFH in both U.S. and global practice relative to the more expensive bivalirudin. But the MATRIX results, as well as results published on the same day as the MATRIX report from the Chinese BRIGHT (Bivalirudin vs. Heparin With or Without Tirofiban During Primary Percutaneous Coronary Intervention in Acute Myocardial Infarction) study (JAMA 2015 [doi:10.1001/jama.2015.232]) that also compared bivalirudin and UFH, seemed to throw the balance of evidence back in bivalirudin’s favor.
MATRIX “was a win for bivalirudin,” commented Dr. Sanjit S. Jolly, an interventional cardiologist at McMaster University in Hamilton, Ont. “Clearly mortality is the most important endpoint, and the totality of data from all the trials suggest that bivalirudin reduced mortality, compared with UFH. I think that physicians who stopped using bivalirudin after HEAT-PCI may go back to bivalirudin,” he said during a press conference at the meeting.
“Following HEAT-PCI there was a shift to greater use of UFH and more selective use of bivalirudin, even in the United States, and especially for patients with ST-elevation MI,” commented Dr. David E. Kandzari , director of interventional cardiology at the Piedmont Heart Institute in Atlanta. The new MATRIX findings “will probably prompt clinicians to revisit this given that MATRIX was the largest study to compare bivalirudin and UFH. That is not to discount the HEAT-PCI findings, but that was a much smaller trial and at a single center.”
Bivalirudin treatment results in additional expense, compared with UFH, and physicians are “under pressure to cut costs, so following the HEAT-PCI results, there was a big reduction in bivalirudin use. But with the subsequent BRIGHT results and now the MATRIX results, I think there will be an uptick again in bivalirudin use,” commented Dr. Cindy L. Grines, an interventional cardiologist at the Detroit Medical Center. The MATRIX results make her “more confident about the benefit from bivalirudin,” she said in an interview.