MATRIX Shows Transradial Access Should Be Preferred for Most Catheter-Based Coronary Interventions

March 16, 2015—Results from the access-site program of the MATRIX study of minimizing adverse hemorrhagic events by transradial access site and systemic implementation of bivalirudin (Angiox, The Medicines Company) demonstrated that patients with acute coronary syndrome (ACS) undergoing coronary angiography had a significantly lower risk of major bleeding and death if the procedure was conducted by transradial access rather transfemoral access.

The MATRIX access site program findings were presented at the American College of Cardiology’s (ACC) 64^th annual scientific session in San Diego, California, and published simultaneously online in The Lancet.

Marco Valgimigli, MD, is the lead investigator of the study. Dr. Valgimigli is Associate Professor of Cardiology and senior interventional cardiologist at the Erasmus University Medical Center in Rotterdam, the Netherlands.

According to the ACC, the MATRIX investigators advised that these results should prompt a re-evaluation of clinical guidelines and that transradial access should be the preferred approach for most transcatheter coronary procedures. However, the femoral approach is still appropriate for certain types of procedures that require the use of larger devices, such as transcatheter aortic valve replacement.

The study showed a hospital’s level of experience with the transradial approach had a substantial impact on patient outcomes because the radial approach is more difficult to perform. To build the level of experience necessary to maximize the benefits of the radial approach, an interventionist should use the radial approach in at least 80% of cases, advised Dr. Valgimigli.

The study is the first large trial to show radial access improves patient outcomes and that it reduces dangerous bleeding beyond the bleeding that can occur near the insertion point. In the United States, interventional cardiologists currently use the arm for catheter-based heart procedures in less than 15% of cases, whereas in Europe the approach is used in approximately 50% or more of cases.

The ACC announcement stated that the study did not show a significant reduction in one of its two primary endpoints, a composite rate of death, heart attack, or stroke at 30 days after the procedure. However, the second primary endpoint, which included those events plus major bleeding, showed a significant reduced risk in patients randomized to transradial access rather transfemoral access. In addition, transfemoral-access patients faced a significantly higher risk of death, which was driven by increased bleeding complications in these patients.

In the ACC press release, Dr. Valgimigli commented, “I believe the evidence from our study should compel a switch to the radial approach as the preferred method. I hope that a new generation of interventional cardiologists will be specifically trained in the radial approach and that more medical centers will build up their expertise in this procedure.”

He added, “This study shows that interventional cardiologists who are experienced with the radial approach have nothing to lose and everything to gain by using the arm as the access point for these procedures.” Dr. Valgimigli noted that in addition to improving outcomes, the radial approach can also save on medical costs because it typically results in a quicker recovery and shorter hospital stay.

As summarized in the ACC press release, the MATRIX access-site study randomized more than 8,400 angiography patients at 78 hospitals in four European countries to undergo angiography via transradial or transfemoral access. All study participants had ACS. Patients experienced major bleeding, death, heart attack, or stroke within 30 days in 9.8% of transradial access cases versus 11.7% in transfemoral cases. The difference was largely attributable to major bleeding (1.6% transradial access vs 2.3% transfemoral) and death (1.6% transradial vs 2.2% transfemoral).

The MATRIX investigators attributed the study’s failure to meet its other coprimary endpoint to a higher-than-usual bar for statistical significance, a result of the inclusion of two coprimary endpoints in the study rather than only one. The study found no differences with respect to rates of heart attack or stroke, noted the ACC announcement.