WASHINGTON – The clinical and technical success rates are higher among patients undergoing robotic percutaneous coronary interventions through radial than femoral access, according to registry data presented at CRT 2017 sponsored by the Cardiovascular Research Institute at Washington Hospital Center.
Although both the clinical and technical success rates were high with either type of access, the advantage for radial over femoral access was significant for each, reported Ali Pourdjabbar, MD, an interventional cardiologist completing his fellowship at the University of California, San Diego. However, as this was not a randomized trial, he placed emphasis on the message that robotic percutaneous coronary intervention (PCI) is safe and effective when performed through either access point.
Clinical success, defined as less than 30% residual occlusion with TIMI3 flow and no major adverse cardiovascular events, such as myocardial infarction, cardiovascular death, or revascularization, was achieved in 99.4% of the 310 patients treated through radial access and 94.7% of the 191 patients treated through femoral access (P = .002). Technical success, defined as PCI performed without any manual assistance, was achieved in 92.4% of procedures performed through radial access and 86.7% of those performed through femoral access (P = .03).
There were no significant differences in the two groups for contrast use or fluoroscopy time, but the time to completing PCI was shorter with the radial approach (57 vs. 66 minutes; P less than .04).
However, the groups did differ in baseline characteristics, according to Dr. Pourdjabbar. Patients undergoing robotic PCI through a radial approach were younger, less likely to have diabetes, and less likely to have received a prior PCI. Most importantly, they were less likely to have complex lesions. Patients treated with radial access had higher average body mass indexes.
“It is important to recognize that this was a nonrandomized, retrospective analysis,” Dr. Pourdjabbar emphasized. He noted that one reason for this analysis was to confirm that efficacy and safety was just as good with radial access, which although an approved robotic approach, was supported with fewer data at the time that the device became available.
However, it is notable that 60% of the robotic procedures were done with the radial approach, which is approximately double the proportion currently performed in the United States when done manually, according to data presented by Dr. Pourdjabbar. He noted that radial access has been more commonly used outside of the United States, but rates have also started climbing in this country, rising from less than 5% of cases in 2005 to nearly one third of cases in the most recent analysis. It is unclear why robotic procedures are performed more frequently through radial access, but Dr. Pourdjabbar speculated that centers innovating with robots might also be in the vanguard of the movement toward radial PCI.
Of reasons to consider robots, Dr. Pourdjabbar suggested that the safety advantages for the interventionalist are particularly compelling. Citing a variety of data associating cath lab radiation exposure to health risks for physicians and staff, Dr. Pourdjabbar explained that the operator performs robotic PCI from a shielded cockpit that completely eliminates exposure to radiation. A next generation robotic device, called the CorPath GRX System, is expected to further reduce opportunities for radiation exposure by allowing the operator to disengage the guide catheter in cases when this had to be done manually with the first generation CorPath 200 system.
Asked about the learning curve of PCI robotics, Dr. Pourdjabbar said that the principles appear to be grasped quickly by interventionalists, but he acknowledged that his experience as a training fellow has been limited. However, Rajesh V. Swaminathan, MD, an interventionalist affiliated with Duke University, Durham, N.C., who has experience with robotic PCI, reported that although the tactile sense of the guide wire is lost in robotic PCI, the procedure has typically proceeded more quickly in his hands once access is achieved.
“The greatest learning curve may with the staff that has to get used to not having the interventionalist at the table,” observed Dr. Swaminathan, who was a moderator of the session in which these data were presented.