By Mehmet Cilingiroglu, MD
Technological advances within the last decade have made TMVR increasingly feasible and safe in clinical practice. TMVR in patients with severe MR has successfully reduced mortality, patient symptoms, and disease morbidity, improved quality of life, and facilitated reverse LV remodeling. Recent randomized controlled trials on MitraClip use in secondary MR have reinvigorated interest in this disease. TMVR with the MitraClip system requires comprehensive TEE guidance throughout the MitraClip procedure to achieve exact positioning of the clip. Thus, TMVR procedures are commonly performed under GA because of the prolonged TEE duration. Furthermore, breath-holding and ventilation maneuvers can facilitate TMVR in patients with challenging MV anatomies. However, GA is associated with disadvantages, including perioperative hypotension, catecholamine induced cardiotoxicity, oropharyngeal and tracheal injury, pneumonia, difficulty in weaning, risk of ancillary procedures (for example, radial artery line placement), more challenging esophageal intubation for TEE, higher likelihood of oropharyngeal or esophageal injury, cost and interruption of work-flow, delay in identification of serious problems, and neurological complications. It has been demonstrated that perioperative hypotension and duration of anesthesia (deep hypnotic time) are predictors for complications and prolonged hospital stay.
Recent studies revealed that DS might be an alternative to GA in TMVR. Horn et al investigated whether the MitraClip procedure could be performed safely using DS without GA. They analyzed 232 MitraClip procedures (76 procedures with GA, 156 procedures with DS). The primary combined safety endpoint was defined as the occurrence of major adverse cardiac and cerebrovascular events, conversion to surgery, major vascular complications, or pneumonia, and did not differ between the GA and DS groups. Intraprocedural conversion to GA was required in 2% of the patients in the DS group. There were no differences in procedural success rates or clinical outcomes between the groups at 3-month follow-up. Catheterization laboratory prep time and intensive care unit stay were shorter in the DS group than in the GA group.
In another study, Patzelt et al compared patients undergoing TMVR with GA or DS. They observed that propofol and norepinephrine doses were significantly lower in the DS group, while procedure time, fluoroscopy time, and dose area product were significantly higher in the GA group. There was no significant difference between the GA and DS groups with respect to overall bleeding complications, postinterventional pneumonia, or C-reactive protein levels. Significantly fewer patients with DS needed a postinterventional stay in the intensive care unit. Importantly, there was no significant difference between DS and GA regarding intra-hospital or 6-month mortality.
To the best of our knowledge, this is the first study to date in United States to compare CS with GA in TMVR patients. In contrast to other TMVR studies, our study applied MCS, which is a lighter sedation than DS. Working together with our anesthesia team, we structured a well-designed and easily applicable MCS protocol for TMVR. Our data reveal that MCS for TMVR is safe and feasible. No disadvantages with respect to procedural outcome or complications were observed. Although fluoroscopy time is similar in our study with the results of Patzelt et al procedural duration time was significantly shorter than the previous two reports. In our cost analysis, we were able to save about $6,875.00 per patient undergoing MitraClip procedure, as these patients were extubated right in the cardiac catheterization laboratory instead of in the postanesthesia care unit and went directly to regular telemetry unit for observation.
TMVR can be performed safely and effectively under MCS. Applying MCS may simplify the TMVR procedure while resulting in shorter procedural times, increased patient satisfaction, and overall procedural cost reductions. A structural heart disease team approach that includes the anesthesiology specialists should be applied, with the focus on the patient for the best mode of sedation, GA versus MCS. For those patients who can be done using MCS, this will lead to increased patient comfort, reduced cost, reduced morbidity, and more streamlined patient flow in the cardiac catheterization laboratory. Further large-scale, randomized controlled studies are needed to confirm these initial findings regarding MCS for TMVR.
Sources and Further Reading
Ates I, Marmagkiolis K, Kose G, et al. Evaluation of Effectiveness and Safety of Left Atrial Appendage Closure Under Moderate Conscious Sedation. J Invasive Cardiol 2020;32(9):358-362. Epub 2020 June 8.