Episode #132 Keeping Patients Safe During Interventional Cardiology Procedures

Hello and welcome back to the Anesthesia Patient Safety Podcast.  My name is Alli Bechtel, and I am your host. Thank you for joining us for another show. We hope that your new year is off to a great start, and I bet it is especially if you tuned in to Episode #131 last week about keeping patients safe during off-site cardiology procedures. We are back for Part 2 today.

Before we dive into the episode today, we’d like to recognize Blink Device Company, a major corporate supporter of APSF. Blink Device Company has generously provided unrestricted support to further our vision that “no one shall be harmed by anesthesia care”. Thank you, Blink Device Company – we wouldn’t be able to do all that we do without you!”

Electrophysiology and interventional cardiology procedures are rapidly expanding, and this means that there is a demand for anesthesia professionals to provide care during these procedures which may be off-site and remote from the operating rooms with unfamiliar environment, equipment, or team members for often complex procedures with complex patients who may have significant co-morbidities. Does this sound familiar? There is a call to action for anesthesia professionals to be aware of the safety considerations during these procedures in order to keep our patients safe. Our featured article today, from the February 2022 ASPF Newsletter, is once again, “Anesthetic Safety Considerations for Off-site Cardiology Procedures” by Todd Novak and Chelsea Zur. To follow along with us, head over to APSF.org and click on the Newsletter heading. Fifth one down is newsletter archives. Then click on the February 2022 Newsletter and scroll down until you get to our featured article today. I will include a link in the show notes as well.

Let’s start with a quick review from last week. Remember, patients with the following risk factors may benefit from an in-person appointment at the Preoperative Anesthesia Clinic.

• Morbid obesity, obstructive sleep apnea, and difficult airway
• Congestive heart failure or inability to lie flat
• Severe pulmonary disease
• Substance abuse disorder, psychiatric disorders
• Complex arrhythmia ablations
• Procedures requiring general anesthesia

It is so important to conduct a complete preoperative evaluation which should include the following:

• History and physical exam
• Review of allergies with particular attention to contrast allergies
• Medication reconciliation with particular attention to anticoagulants and heart failure medications. Keep in mind that for most procedures except ablation procedures beta-blockers and antiplatelet medications are often continued.
• Review of the cardiology workup including 12-lead electrocardiogram, echocardiogram, and cardiac monitoring
• For patients with cardiovascular implantable electronic devices, an interrogation within 3-6 months of the elective procedure to evaluate the manufacturer, current settings, indication for placement, and dependence on the device.

And now, it’s time to pick up right where we left off with a review of the interventional cardiology procedures. We are headed into the catheterization Laboratory. Here we go.

Let’s start with transcatheter aortic valve replacement or TAVR. Years ago, this procedure was used only for patients with severe, symptomatic aortic stenosis who were too high risk for surgical aortic valve replacement. Now, it is approved for patients who are low risk with symptomatic aortic stenosis and the evaluation for asymptomatic patients with severe AS is ongoing. In the United States, there are two TAVR systems available with unique characteristics. The Edwards Sapien valve is a low profile, balloon expandable valve that cannot be repositioned after it is deployed. The Medtronic CoreValve family of valves have a higher profile and are self-expanding with the added benefit of being able to partially recapture and reposition if needed for optimal placement. Placement of the balloon expandable Sapien valve or performance of a balloon aortic valvuloplasty before valve deployment requires rapid ventricular pacing at 160-220 beats per minute. This is accomplished by using a temporary transvenous pacer with the goal to minimize blood flow in the left ventricular outflow tract which then reduces the risk for the valve to migrate during deployment. Rapid ventricular placement and the resulting hypotension may be poorly tolerated in patients with aortic stenosis. Keep in mind that the hypotension may be brief and only temporary, but vasopressor administration with phenylephrine or norepinephrine may be needed for persistent hypotension. Rebound hypertension may occur following termination of the rapid pacing and valve deployment. The overall mortality for TAVR is 1-4%. Complications from this procedure may contribute to significant morbidity. Be prepared for the most common complications including the following:

• Vascular injury
• Aortic dissection
• Ventricular perforation leading to tamponade
• Valve malposition and malfunction
• Annular rupture
• Stroke
• Myocardial infarction
• High degree atrioventricular nodal block requiring permanent pacemaker placement

Let’s review some of the important parts of the procedure. The most common approach to device placement is transfemoral at 95%. Other approaches that may be used include subclavian/axillary, transaortic, transapical, transcaval, and transcarotid. The transfemoral approach causes the least patient discomfort and allows the procedure to be performed with minimal sedation. The technology for this procedure has advanced with more skilled interventional cardiologists so that mild to moderate sedation for TAVR has become a more popular approach. Benefits of sedation for TAVR include less vasopressor use, modest decrease in in-0hospital mortality, shorter hospital length of stay, and more frequent discharge home. For TAVRs performed with local anesthesia and sedation, valve positioning is confirmed with fluoroscopy and transthoracic echocardiography. There are times when general anesthesia with an endotracheal tube may be required for TAVR including when transesophageal echocardiography is needed instead of transthoracic, when a percutaneous transfemoral approach is not feasible due to inadequate iliofemoral vasculature, and when a surgical cutdown for vascular repair is required. The benefits of general anesthesia include a quiet surgical field, control of the airway, and early recognition of surgical complications with TEE.

For sedation and general anesthesia, invasive blood pressure monitoring is needed with a radial arterial line or by transducing the arterial sheath used by the interventionalist. In addition, large bore, peripheral IV access is needed as well as immediate access to cross-matched blood and the ability to access the large bore venous sheath as well.

We are staying in the interventional cardiology lab but moving on to our next heart valve to talk about transcatheter mitral valve repair or replacement. This procedure may be used for patients with symptomatic, moderate to severe or severe mitral regurgitation who are not candidates for surgical valve repair. The MitraClip device is FDA approved and the procedure may be performed in the cardiac catheterization lab or hybrid operating room. The MitraClip device is a leaflet repair device which is designed to create an edge-to-edge repair and double orifice mitral valve to reduce the degree of mitral regurgitation similar to the surgical Alfieri stitch. This procedure is performed under general anesthesia with an endotracheal tube with placement of a TEE probe after intubation. The first step is transfemoral venous cannulation by the proceduralist. Then fluoroscopy and TEE are used to guide the device across the intra-atrial septum, into the left atrium and finally across the mitral valve. 2D and 3D images on transesophageal echocardiography are required to position the device appropriately. After the MitraClip is released, it is important to assess the remaining mitral regurgitation and if there is any iatrogenic stenosis on TEE. If there is suboptimal placement, the clip can be retrieved, repositioned, or removed. In addition, more than one clip may be used if needed reduce the severity of mitral regurgitation. A radial arterial line is often placed for close blood pressure monitoring and frequent blood draws to ensure adequate levels of anticoagulation during the procedure. Large bore peripheral IV access is recommended due to the risk for emergent conversion to open surgical repair and for vasopressor and IV fluid administration, although central venous line placement is not usually required. Be sure to have cross-matched blood available in the procedure room as well. Here are the complications that are unique to this procedure:

• Partial clip detachment or embolization
• Tamponade
• Bleeding at access sites
• Iatrogenic mitral stenosis

Another important consideration is the creation of an iatrogenic atrial septal defect at the site of the septal punction. It is important to evaluate this site for shunt and take care to remove all air from intravenous lines to prevent stroke.

The next procedure in the interventional cardiology lab is the transcatheter mitral valve replacement. You may not have seen this procedure yet since it is less commonly performed. It is FDA approved for high-risk patients that have already had surgery on their mitral valve with a prior replacement with a bioprosthetic valve or repaired with an annuloplasty ring. Remember those Edwards Sapien valves that we talked about for TAVR procedures? Well, the Edwards Sapien 3 or Sapien 3 Ultra valves are used for this procedure for valve in valve or valve in ring replacement. In addition, TAVR valves may be used off-label for patients with end-stage, refractory native mitral valve disease. General anesthesia with placement of an endotracheal tube and guidance with TEE is necessary for this procedure. Use of this procedure is limited due to poor outcomes, but we will have to see if there are any improvements with advances in the technology and technique over time.

Before we wrap up for today, we have a few more off-site cardiology procedures to review. Patient undergoing diagnostic transesophageal echocardiography may require anesthesia care for the procedure. TEE may be needed to assess cardiac structures that are not well visualized on TTE. TEE may be preferred for valvular pathology and surgical planning, urgent assessment of acute aortic pathology such as for an aortic dissection, diagnosis of infective endocarditis, and prior to nonemergent direct-current cardioversion or ablation to evaluate for intracardiac thrombus. Have you taken care of a patient for this procedure before? Anesthesia care may involve moderate sedation with careful monitoring to avoid apnea. In addition, topicalization of the pharynx with lidocaine may be used to decrease the amount of sedation. Historically, topical benzocaine was used, but this practice is used less due to the risk for methemoglobinemia. Depending on the patient’s comorbidities, intravenous glycopyrrolate may be used to decrease oral secretions. Propofol is often used for sedation during TEE probe placement since has a rapid onset and metabolism with minimal residual effects following the procedure. Sedation for the procedure may be accomplished with Propofol bolus 0.25-0.5mg/kg for TEE probe insertion followed by low dose propofol infusion or incremental propofol boluses during the less stimulating TEE exam. Dexmedetomidine with a bolus 0.5-1 mcg/kg over 10 minutes followed by an infusion of 0.2-1mcg/kg/hr may be used with airway topicalization as well. General anesthesia with an endotracheal tube may be required for high-risk patients with a difficult airway, high aspiration risk, or impaired neurologic status. Keep in mind that TEE is an aerosolizing procedure and elective use should be avoided in patients with COVID-19 unless the findings will change clinical management.  TEE is a safe procedure, but be on the lookout for the following complications which may require emergent intubation and resuscitation:

• Laryngospasm
• Aspiration
• Pharyngeal Injury
• Perforated Viscus
• Hemorrhage

We are keeping the energy level up as we review the next procedure – Direct-Current Cardioversion. The anesthetic goals include rapid onset and offset and avoidance of apnea with a patient who is not responsive to tactile or verbal stimulation. This may be accomplished with a propofol bolus 0.25-0.5mg/kg after placement of standard ASA monitors including capnography. Once deep sedation has been achieved, the electrical shock can be delivered. Keep in mind that patients may have low cardiac output, slow circulation time, and delayed onset of induction medications and there is a risk for oversedation. Be prepared to treat hypotension and bradycardia and have emergency drug readily available including phenylephrine, ephedrine, glycopyrrolate, or atropine. Prior to the shock external defibrillation pads should be placed in case of post-cardioversion asystole and need for extrinsic pacing. Don’t forget to interrogate any implantable electronic devices including pacemakers and defibrillators following the procedure as well.

We made it to the end of the article and the end of the show today. The authors leave us with a call to action for anesthesia professionals who play an important role in the care team to be familiar with the challenges of these off-site and often complex cardiology procedures, have a knowledge base about the procedures, be able to communicate with the cardiology team, and be prepared for complications in order to help keep patients safe.

If you have any questions or comments from today’s show, please email us at [email protected]. Please keep in mind that the information in this show is provided for informational purposes only and does not constitute medical or legal advice. We hope that you will visit APSF.org for detailed information and check out the show notes for links to all the topics we discussed today.

Thank you for starting the new year by joining us for this show. Did you know that you can find us on twitter, Instagram, and Linked In!  See the show notes for more details and we can’t wait for you to tag us in a patient safety related tweet or like our next post on Instagram or connect with us on Linked In!! Follow along with us for anesthesia patient safety pictures and stories all week long!!

Until next time, stay vigilant so that no one shall be harmed by anesthesia care.

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