Transcatheter Aortic Valve Replacement: A Case Report

Oklahoma Heart Institute recently performed the first transcatheter aortic valve replacement procedures in Tulsa, Oklahoma. We present the details of one of the cases.

Clinical presentation

J.S. is an 87-year-old female with severe calcific aortic stenosis and New York Heart Association (NYHA) class III-IV congestive heart failure symptoms who is referred for transfemoral transcatheter aortic valve replacement (TAVR).  Her past medical history is remarkable for coronary artery disease for which she underwent three-vessel coronary artery bypass grafting in 1996. In addition, she has severe oxygen-dependent chronic obstructive pulmonary disease (FEV1 0.65 L, 40% predicted) with severe pulmonary hypertension, stage III chronic kidney disease, hypertension, and type II diabetes mellitus on insulin therapy. The predicted operative mortality for surgical aortic valve replacement based on the Society for Thoracic Surgeons database (STS score) was calculated to be 24.3%. She was evaluated by two cardiothoracic surgeons for surgical aortic valve replacement and was deemed inoperable in light of her history and predicted surgical risks. 

The patient had worsening congestive heart failure symptoms to the point that she was short of breath at rest and with minimal activity (NYHA class III-IV). Because of her advanced age and multiple co-morbidities, there was concern as to whether TAVR would significantly impact her symptoms, quality of life and survival. Therefore, balloon aortic valvuloplasty (BAV) was performed on January 18, 2012 at Oklahoma Heart Institute Hospital to assess for symptomatic and functional improvement, and therefore help gauge the relative contribution of severe aortic stenosis to her overall condition (Figure 1). Following BAV, the patient had a marked and dramatic improvement of her congestive heart failure symptoms to NYHA class II as well as improvement in her functional capacity, indicating that she would likely respond very well to TAVR. In addition, despite her multiple co-morbidities, she remained an active and independent individual who greatly wished to continue to enjoy her hobbies, and many children and grandchildren.

Given these considerations, she was felt to be an appropriate candidate for transfemoral TAVR and comprehensive pre-procedural testing was performed at Oklahoma Heart Institute, including transthoracic and transesophageal echocardiography, cardiac catheterization with coronary and bypass graft angiography, as well as computed tomographic (CT) evaluation of the aortic valve/annulus, aorta and iliofemoral vessels (Figures 2-5). These studies were performed, interpreted and reviewed by the multidisciplinary Heart Team at Oklahoma Heart Institute, and the patient was felt to be an appropriate candidate for transfemoral TAVR utilizing a 23 mm Edwards Sapien transcatheter heart valve.

Procedural details

The patient was admitted electively to the Oklahoma Heart Institute Hospital on May 16, 2012, in preparation for scheduled transfemoral TAVR on the following day. On May 17, she underwent successful transfemoral TAVR with a 23 mm Edwards Sapien transcatheter heart valve utilizing the RetroFlex 3 delivery system. The procedure was performed in the newly-constructed, dedicated, hybrid cardiac catheterization laboratory at Oklahoma Heart Institute Hospital. 

General endotracheal anesthesia was utilized, as was intra-procedural transesophageal echocardiography (TEE). The procedure was performed completely percutaneously, without the need for surgical vascular access. The native aortic valve was crossed, and the Edwards Sapien valve was deployed with rapid pacing after careful positioning under fluoroscopic and TEE guidance (Figure 6; video available at www.cathlabdigest.com). Following deployment of the valve, TEE demonstrated a well-positioned valve with trivial central aortic regurgitation and no paravalvular regurgitation. Clinically, the patient tolerated the procedure very well and was extubated without difficulty at the conclusion of the procedure while still in the hybrid catheterization laboratory.

Post-procedural course

The patient was admitted to the cardiovascular intensive care unit (CVICU) immediately following successful TAVR as per institutional protocol. Clopidogrel was administered on arrival to the CVICU. She did very well immediately following the procedure and ambulated without difficulty on post-procedure day #1, at which time she was transferred out of the CVICU to a cardiac telemetry floor. The patient underwent follow-up transthoracic echocardiography on post-procedure day #1 that demonstrated that the Edwards Sapien aortic valve prosthesis was functioning well, with a mean gradient of 13mmHg and trivial-mild central aortic regurgitation. She continued to do very well and was discharged home on post-procedure day #2 in good condition. The only new medication added to her regimen on discharge was clopidogrel 75 mg PO daily which she was instructed to continue for six months. Outpatient follow-up in the Oklahoma Heart Institute TAVR clinic was scheduled for one week after discharge.

The patient was seen in the Oklahoma Heart Institute outpatient TAVR clinic one week following her procedure. She reported significant improvement in her congestive heart failure symptoms at that visit (NYHA class II) as compared to her baseline prior to the procedure (NYHA class III-IV). In addition, her total walk distance had improved significantly. She also reported that she was no longer using her home oxygen on a regular basis. The femoral artery vascular access site for TAVR was examined carefully and noted to be unremarkable. She was advised to continue her aspirin and clopidogrel therapy as previously instructed and six-month outpatient follow-up was scheduled.

Discussion

Transfemoral transcatheter aortic valve replacement using the Edwards Sapien transcatheter heart valve system is indicated for patients with severe symptomatic native aortic valve stenosis who have been deemed inoperable for open surgical aortic valve replacement by a cardiothoracic surgeon and in whom existing co-morbidities would not preclude expected benefit from correction of aortic stenosis. The landmark PARTNER trial demonstrated significant and marked improvements in survival, symptoms and quality of life in patients treated with this device, as compared with standard medical therapy.  In addition, current two-year follow-up data from this trial indicate continued excellent performance of this valve prosthesis.

As described herein, our patient J.S. met the criteria for transfemoral TAVR and underwent this procedure successfully at Oklahoma Heart Institute with an excellent result.

The author can be contacted at Kamran.Muhammad@oklahomaheart.com. 

For more information on Oklahoma Heart Institute’s TAVR program, including videos of the first TAVR procedure in Tulsa, as well as our newly-constructed hybrid cardiac catheterization laboratory, please visit: https://www.oklahomaheart.com/tavr 

References

1. Leon MB, Smith CR, Mack M, et al. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med 2010;363(17):1597-607.
2. Makkar RR, Fontana GP, Jilaihawi H, et al. Transcatheter aortic-valve replacement for inoperable severe aortic stenosis. N Engl J Med 2012;366(18):1696-704.

The Hybrid Lab at Oklahoma Heart Institute

Cath Lab Digest talks with Kamran I. Muhammad, MD, FACC, FSCAI, Interventional Cardiology, Oklahoma Heart Institute, Tulsa, Oklahoma

Can you tell us about the new hybrid lab?

Oklahoma Heart Institute recently built a brand-new, dedicated hybrid cardiac cath lab, the only such lab in Tulsa and in the region. This lab was planned, custom designed, and constructed from the ground up over the past year to bring advanced technologies and capabilities to our city and region for the benefit of our patients. This type of advanced lab is an important requirement for hybrid cases such as transcatheter aortic valve replacement (TAVR). Our hybrid lab is located in the cardiac catheterization lab. It is a Philips hybrid lab and officially opened in April 2012. As you know, hybrid labs combine the capabilities of an operating room and a cardiac cath lab in order to provide this type of advanced care.

Since it is located in the cath lab, is it under cath lab management?

Yes, it is under cath lab management. When not being used for hybrid cases, it is used for traditional coronary and peripheral cases. Electrophysiology also uses it for their more difficult lead extractions. We also perform our aortic stent grafts in this lab.

Does your lab have 3D overlay?

Yes, our lab has all those capabilities. It has a built-in system for allowing registration of a live fluoroscopy image with an off-line CT that can be preloaded into the system and that can aid in optimal positioning of the valve. The fluoroscopy in the lab is excellent. It, of course, has advanced digital subtraction and image overlay capabilities. It also has the capability to do a real-time CT scan using the detector/II in the lab.

When did the first case take place in the lab?

The hybrid lab has been up and running since April, but we did our first TAVR on May 2nd (we actually did two that day). These were the first cases in Tulsa and in the region, and May 2nd was the date our TAVR program officially launched. 

How many cases have you done since?

We have done ten total cases since May 2nd. The average age of our treated patients is 83, with seven men and three women. We have had excellent procedural and clinical outcomes in all cases, with no major complications or adverse events.

What are the primary challenges with the TAVR procedure?

I think there are multiple areas that are important and challenging. Careful and meticulous pre-procedural planning is essential to making the procedure safe and successful.  When it comes to the procedure itself, vascular access is critical — as with any interventional procedure, but definitely more so with this procedure, because we are using such large catheters and sheaths. So getting vascular access as perfect as possible goes a long way in preventing vascular complications. Optimal positioning of the valve before deployment is also critical — making sure that the valve is optimally positioned and placed before deployment, because once it is deployed, you don’t have many options in terms of correcting a mal-positioned valve. So I think those are two of the most critical portions of the procedure itself. Clearly our cardiac anesthesiologists are also working very hard on these inoperable patients to keep them stable under general anesthesia during this case. 

As you began this program, what were the challenges you faced?

I came to Oklahoma Heart Institute in August 2011, and was recruited from The Cleveland Clinic to develop this program. I have been very fortunate to have very supportive organization and leadership. Dr. Wayne Leimbach Jr., chief of cardiology and director of the cath lab, recruited me, and has been extremely supportive and a major driving force in making our TAVR program successful. All of my colleagues at Oklahoma Heart Institute have also been very supportive and excited about this program, and many have referred their patients for evaluation. In addition, the leadership at our parent company, Ardent Health Services, as well as our local leadership at Oklahoma Heart Institute and Hillcrest HealthCare System have been very vested in this project, from investing in and building the hybrid lab, to allocating additional resources and supporting us the entire way up to the time we launched our program and performed the first TAVR cases in Tulsa. The folks at Edwards Lifesciences, the company that developed and markets the FDA-approved Sapien transcatheter heart valve (which is currently the only commercially available transcatheter valve in the U.S.), have also been very instrumental and supportive in the successful launch of our program. By virtue of these factors, it has been a great environment in which to launch this program.Clearly, a great deal of work has been put in by many different people and departments to get a successful program up and running, and it has really been a team effort. We have had to go identify patients, screen them, and educate and inform these patients and their families about TAVR. As I mentioned in some of the details in the case report, we traveled to Columbia University/New York Presbyterian Hospital to present our potential TAVR cases. As part of the requirements for starting a transcatheter valve program, attendance at a training program is mandatory. An important part of this training involves each potential hospital presenting several cases that are reviewed and approved by the faculty at the training program. Those are the steps along the way: building an environment in which a program can thrive, developing a process to identify patients and screen them, going through the training, including presentation of cases to other physicians at training, and then actually doing the first cases here at Oklahoma Heart Institute.

It is truly a multidisciplinary effort. Many people from different departments are involved, and we are very glad it has been a success. In addition to the team members from interventional cardiology, myself and Dr. Wayne Leimbach Jr., we also have Dr. Paul Kempe and Dr. James Whiteneck of cardiac surgery as an integral part of our team. Our valve coordinators, Anna Richardson, LPN, and Georgianne Tokarchik, RN, play a very important role in the screening, education and follow-up of our patients, and are also continually available as resources to patients and their families. Dr. Victor Cheng and Dr. Alan Kaneshige are experts in cardiovascular imaging from our practice, and they play extremely important roles in the pre-procedural, imaging-based evaluation of our patients, as well as during the procedure itself. Our cardiac anesthesiology team includes Dr. Mark Halterman and Dr. Clorinda Robles, who are very involved in pre-procedural evaluation and, of course, during procedural anesthetic management. And, of course, we have a tremendously talented cath lab organization, from the leadership in the lab to the nurses, technologists and clinical specialists that work with us daily, which has made this program possible. It is a big team and a big effort, and we are proud of our team and the results we have achieved thus far.

The patient in your presented case was 87 years old. Is that advanced age typical for a TAVR procedure?

Yes, absolutely. The average age in the PARTNER trial, Cohort B, which looked at inoperable patients, was 83 years old. Transcatheter aortic valve replacement is only currently indicated for patients with severe symptomatic aortic stenosis who are inoperable, meaning they can’t have traditional open-heart surgery for surgical valve replacement. So they tend to be, by virtue of that, older patients with multiple co-morbidities that make their operative risk prohibitive. So it is fairly normal for someone to be in that age range for this procedure.

You note the patient had several procedures prior to the actual TAVR procedure: angio, CT, bypass…is there special attention paid to cumulative radiation and contrast media dosing?

Yes. This procedure is complex enough that it necessitates all that testing be done before we can even know if a patient is a candidate. Patients must have coronary angiography and a cardiac cath to evaluate their coronary anatomy, aorta and iliac vessels. Similarly, a CT scan is done to assess their native aortic valve and annulus size, and assess for suitability of transfemoral access. We try to space all those procedures out over the course of weeks to mitigate the risk of contrast-induced nephropathy. Clearly each of these procedures, cath, CT, and TAVR, have radiation associated with them. However the radiation doses are small with each of these tests, and these patients are relatively elderly, so things like the risk of cancer due to procedural radiation are not a big concern.  The deterministic effects of radiation are always a concern, but we strive very hard to limit radiation doses and thus far we have not had a problem.  

Once a patient is identified as suitable for TAVR, how long is it until they have their procedure?

I think it is variable from center to center, because there are so many moving parts. An important part of timing hinges on how symptomatic a patient is. If the patient is very symptomatic, we tend to move things along as quickly as possible. If they are stable and symptomatic, then it is probably acceptable to do the procedure more electively than urgently. But I would say that from the time that we first meet the patient as a new patient in clinic, to the time they have TAVR, it currently takes 2-3 weeks between those two events. Most of that time is spent in various testing and evaluation stages. Clearly, we don’t want to do all the testing in one day in these elderly, frail patients, which may potentially hurt them.

Can you tell us how patients are handled post procedure?

Currently, the system that is commercially available, the Edwards RetroFlex 3 sheath and delivery system, comes in two large sizes: either a 22 or 24 French system, depending on which size valve is being placed. We have been doing most of our cases completely percutaneously, meaning surgical access or closure of the femoral artery is not required.  As far as where patients go post procedure, our institutional practice has been to extubate patients in the hybrid lab post procedure and then admit them to the cardiovascular ICU (CVICU). They remain in the CVICU for one night. The next morning they ambulate and, if they are doing well, they are transferred to our cardiac telemetry floor. Patients then spend that first post procedure day on the cardiac telemetry floor, where they are mobilized and ambulating. The next day, post procedure day 2, we typically discharge home. All of our patients have fortunately done very well and this process has occurred for all of them.

Any final thoughts?

We are thankful for our wonderful patients and referring doctors who have placed their trust in our program. We are also proud and excited about the fact that we are the first center in Tulsa and the region to offer this procedure. Nationally, there are only 80 or so hospitals that are able to currently offer this service, so I think it is a great achievement for our local patient population, and for our institution. We hope to continue to grow the program and offer this service to our patients.

There are many exciting new devices in the pipeline both from Edwards Lifesciences, as well as from other companies, that will refine and improve this technology. This is really the first-generation technology that we are using right now, and the newer technologies have the promise of being even lower profile, less invasive, and potentially more efficacious than the current devices. It will mean that even more patients are eligible, because as the devices get smaller, the requirements for iliofemoral access size also drop. The FDA is also currently considering expanding the indications for TAVR based on the PARTNER trial Cohort A data. There are many more exciting things around the corner for transcatheter aortic valve replacement. This is hopefully just the tip of the iceberg.

Dr. Muhammad can be contacted at: Kamran.Muhammad@oklahomaheart.com.