WASHINGTON – Robotic angioplasty may deliver the same advantages when percutaneous coronary intervention is indicated for acute myocardial infarction as currently claimed for an elective PCI, according to results from a proof-of-principle study.
The first robotic PCI system, CorPath 200, was approved by the U.S. Food and Drug Administration in 2012, but the registration trial, called PRECISE (Percutaneous Robotically Enhanced Coronary Intervention), excluded patients with coronary thrombosis, according to a team of investigators at the Frederik Meijer Cardiovascular Institute, Grand Rapids, Mich. The current study focused exclusively on this population.
In “an initial experience” with robotic PCI in 17 acute MI patients led by Dr. Ryan D. Madder, an interventional cardiologist, “technical success” was achieved in 100% of patients with no repeat revascularizations in follow-up so far.
“These preliminary observations support the performance of larger studies to determine the role of robotic PCI in the treatment of acute MI,” said Andrew O’Brien, a medical student at Michigan State University, Ann Arbor, who presented the data at the meeting, sponsored by the Cardiovascular Research Institute at Washington Hospital Center.
The major proven advantage of robotic PCI is that it reduces radiation exposure to the operator, Mr. O’Brien said. While the procedure was performed in this study behind a lead-lined cockpit, it was noted that the operator works solely on the basis of imaging and could be anywhere, including at another facility. In addition, robotic PCI has at least a theoretical advantage of greater precision relative to conventional PCI.
In this study, technical success was defined as less than 30% residual stenosis after PCI in the absence of a PCI-associated death or the need for a repeat revascularization prior to hospital discharge. The median age of the 17 acute MI patients was 59 years with a range of about 10 years younger or older. Most (71%) were male. Radial arterial access was used in all cases.
Only 23% of the patients met criteria for relatively simple lesions (class A or B1). Just over half (53%) had class B2 lesions, which require at least two complicating characteristics, such as moderate tortuosity, irregular contour, or moderate to heavy calcification, and the remainder had class C lesions. In 10 cases (59%), an angiographic filling defect consistent with thrombus was present at the culprit lesion site.
In addition to achieving the goal reduction in residual stenosis without major adverse cardiovascular events in all patients, the investigators reported that procedural time, which averaged 69 minutes from the time of sheath insertion to removal of the guide catheter, was “acceptable.” The longest procedural time was under 100 minutes.
“We used the same criteria for evaluating outcomes as employed in the original PRECISE study,” Mr. O’Brien said. He explained that acute MI patients were excluded in the published PRECISE trial data because there was no protocol at that time for converting to a conventional procedure on an urgent basis in the case of unexpected problems. With more experience, there was greater confidence that urgent complications could be addressed.
In the multicenter PRECISE trial, which led to approval of the robotic system, 164 candidates for elective PCI were enrolled (J Am Coll Cardiol. 2013;61[15]:1596-1600). Technical success was 98.8%. Although there was no control arm, radiation exposure was reported to be 95% lower for operators participating in that study than levels found at the traditional table position.
Data from the current study provide preliminary evidence that robotic PCI is feasible for management of acute MI. While confirmatory studies are needed for this indication, the Michigan investigators also advocated more studies to evaluate whether robotic PCI improves outcome. They cited the potential for more precise placement of stents to reduce the risk of complications.
“Robotic PCI is still not very widely performed,” said coinvestigator Andrew LaCombe, who suggested that its potential advantages deserve broader evaluation.
Dr. Madder disclosed a financial relationship with InfraRedx.