Cardiovascular Revascularization Medicine, 2018-07-01, Volume 19, Issue 5, Pages 477-479, Copyright © 2018 “I am a slow walker, But I never walk back.” Since Andreas Gruentzig’s first catheter-based intervention over 40 years ago, the field of interventional cardiology has steadily advanced with the development of improved wires, balloons, stents, and adjunctive devices [ 1 , 2 ]. Despite this remarkable progress, the fundamental approach to percutaneous coronary intervention (PCI) for the operator remains remarkably similar to the process first employed by Dr. Gruentzig decades ago. Interventional cardiologists still stand at the bedside next to the patient and the radiation source, wear heavy lead aprons, and manually manipulate intracoronary devices with a steady hand. The advent of robotic-assisted PCI introduced a major advance in the workflow of interventional cardiology. The concept of a “remote navigation system” was first developed by Beyar et. al. with a prototype that consisted of an operator module tethered to a joystick-controlled motorized drive mounted on the table that was able to advance and retrieve intravascular devices. The system allowed operators to manipulate interventional equipment from a distance, limiting operator radiation exposure and reducing orthopedic risks associated with lead aprons. A pilot study of this system demonstrated the feasibility of robotically assisted PCI [ 3 ], and the modern application of this concept, the CorPath 200 system (Corindus, Waltham, Massachusetts), was approved by the U.S. Food and Drug Administration (FDA) for clinical use to perform robotically assisted PCI in 2012 [ 4 ]. Robotic-assisted remote PCI is of great benefit to the interventional cardiologist. It consistently results in over 95% reduction in operator radiation exposure, thus reducing the occupational hazard associated with the practice of interventional cardiology [ 4 5 6 ]. The results of the pivotal Percutaneous Robotic-Enhanced Coronary Intervention Study (PRECISE), a prospective, multicenter registry published in 2013, demonstrated the safety and feasibility of PCI with the CorPath 200 system in clinical practice [ 5 ]. In this study, 164 patients undergoing robotically assisted PCI were enrolled. There were no device-related complications, and technical and clinical success was achieved in 98.8% and 97.6% of cases, respectively. In this study, only 2 patients (1.2%) required conversion to manual operation in order to successfully complete the PCI. In a single-center subanalysis of PRECISE comparing robotically assisted PCI to consecutive cases performed by the traditional manual approach, robotic PCI was not associated with increased fluoroscopy duration, radiation, or contrast media exposure to patients [ 7 ]. Benefits to patients also include improved accuracy of stent positioning and reduction in geographic miss [ 8 ]. Although PRECISE demonstrated the safety and feasibility of robotically assisted PCI, the study enrolled only low-risk patients with simple coronary anatomy (only 31.7% Type B2 / C lesions) and short lesion lengths (less than 24 mm), and excluded patients who required multiple stents. The strict eligibility criteria limited the generalizability of the study findings to the population undergoing straightforward “simple” PCI. Since the publication of PRECISE, the evidence for robotic interventions has expanded as interventional operators have applied robotic-assisted PCI to increasingly challenging and technically complex lesions. Recent case reports have described robotically assisted PCI in the setting of multiple lesions, cardiac allograft vasculopathy, vein graft interventions, ST-segment myocardial infarction, unprotected left main lesions, and in patients with calcified coronary stenoses requiring coronary atherectomy [ 9 10 11 ]. Mahmud et al. reported a large single-center experience of using the CorPath 200 robotic system in real-life practice of complex PCI [ 12 ]. In this large series of 334 PCI procedures in 315 patients, robotic PCI was compared with manual PCI. The robotic technical success was 91.7% in these complex lesions (78.3% had type B2/C lesions). Although the average procedure duration was longer with the robotic system as compared to manual operation (43 vs. 34 min), the clinical success was identical in both groups (99.1%). In the current study from Harrison and colleagues in this issue of Cardiovascular Revascularization Medicine , the authors focused on the frequency and causes of planned and unplanned manual assistance and conversion to traditional PCI technique [ 13 ]. In this real-world cohort with complex coronary disease, 55.6% had diabetes mellitus, 20.4% had chronic kidney disease, and 30.6% were admitted with acute coronary syndromes. Overall, the authors reported 99% clinical procedural success with robotic-assisted PCI, defined as post-procedural TIMI 3 flow in the target vessel, no significant residual stenosis at the target lesion, and without in-hospital major adverse cardiovascular events following PCI. Among the 108 patients (157 lesions) included in this detailed analysis, manual intervention was required in 20 PCI (18.5%). Partial (or temporary) manual assistance was required in 12 cases (11.1%), defined by the planned or unplanned temporary disengagement of the robotic drive for manual wire or guide catheter manipulation during the procedure, with re-engagement of the robotic drive to complete the intervention. Full manual conversion was required in 8 cases (7.4%), in which disengagement of the robotic drive and bedside manual manipulation of interventional devices was required until the conclusion of the PCI. Issues related to guide catheter and guide wire support and manipulation occurred in 9 cases and were the most common reason to require manual assistance or conversion. Limitations of the interventional system were the reason for manual assistance or conversion in 8 cases, which were most frequently due to the inability to perform kissing balloon inflations, need for embolic protection, or for the use of intracoronary imaging. Adverse events that required manual intervention, such as acute vessel closure or coronary dissection, were rare and occurred in only 3 cases. The findings from this study are an important addition to the literature supporting real-world application of robotic-assisted PCI. The authors should be commended for successfully using the robotic system to perform a large number of complex coronary interventions in consecutive patients, and for their careful documentation of the operator’s bedside involvement during each procedure. However, there are a few limitations of the present report that warrant further discussion. First, only cases that were planned for an initial robotic approach were included. Details of robotic case selection and the patients or lesions that did not undergo robotic PCI are not provided. Second, the authors did not specify the duration of time operators spent at the bedside in the cases that required manual assistance. Additional analyses reporting the duration of time at the bedside and/or the associated radiation exposure may provide additional information regarding these operator risks. Although 1/5 of cases were not performed via a fully robotic approach, this should not necessarily be viewed as a failure of the current robotic platform. Operators still spent less time standing at the bedside as compared to traditional PCI, and they still accrued many of the benefits of the robotic system with respect to reduced radiation exposure and orthopedic concerns. Importantly, in the current report, robotically assisted PCI was performed using the previous generation CorPath 200 system. However, a newer generation of the robotically assisted PCI platform, the CorPath GRX, was FDA approved in fall 2016. The CorPath GRX includes new features, including the ability to manipulate the guide catheter from the robotic console to improve guide support, enabling better deliverability of stents. This addresses one of the major limitations identified by Harrison and colleagues, since nearly half of the procedures that required manual involvement were due to inability to manipulate the guide catheter. Thus, the use of the latest generation of the robotically assisted PCI system may be more beneficial and substantially decrease the need for manual assistance or conversion [ 12 , 13 ]. The present report also highlights opportunities for future robotically assisted PCI platforms. The use of the CorPath 200 system was limited to 0.014” wires, rapid exchange balloons, and stents. These devices represent basic tools of modern-day PCI that are sufficient for the majority of procedures. However, contemporary PCI practice is also associated with complex coronary anatomy, bifurcations, ostial locations, heavily calcified lesions, tortuous vessels, high thrombus burden, and degenerated grafts. There is increased need for the use of accessory intravascular devices such as guide-extension catheters, atherectomy devices, embolic protection, thrombus aspiration, and other specialty devices. Furthermore, intravascular ultrasound-guided PCI has been shown to improve outcomes in complex lesions [ 14 ]. The current robotic system lacks the ability to remotely manipulate these devices. Thus, manual assistance is required to perform intracoronary imaging, orbital and rotational atherectomy, and deploy embolic protection devices. In order to maintain and expand its role in the catheterization laboratory, robotically assisted PCI will have to keep pace with the increasing demands and complexity of PCI. Thus, subsequent iterations of the robotic system will need to address these technical challenges to ensure that fully robotic PCI is feasible for all complex cases. The message delivered by Harrison and colleagues is clear: robotically assisted PCI using the CorPath 200 system is safe and feasible even with complex coronary lesions, and relatively few procedures require manual bailout. Planned or unplanned, partial or complete, conversion from robotic to manual operation during PCI was successful and safe, and was not associated with clinical complications. Even when manual assistance is necessary, patients may still benefit from the precision of the robotic procedure, and interventional cardiologists can enjoy reduced radiation exposure and shorter standing time. The current second-generation robotic PCI system (CorPath GRX) addresses the issue of guide catheter manipulation and is an important step toward more complete robotic PCI. This system is already used in multiple catheterization laboratories around the world, and its routine use is being studied in the large PRECISION GRX Registry. The future may bring additional developments. With ongoing technical evolution, enhanced capabilities may someday permit fully robotic PCI. Until that day, although you may need to wear your lead apron occasionally, robotic-assisted PCI may significantly reduce your radiation exposure. Conflicts of interest: GW reports sitting on the medical advisory board of Corindus. NRS reports no conflicts.