Transcatheter aortic valve replacement (TAVR) is a minimally invasive surgical procedure which repairs the aortic valve without removing the old, damaged valve. Instead, the TAVR procedure delivers a replacement valve into the aortic valve's place through a catheter, which makes the procedure somewhat similar to a stent placed in an artery.
The TAVR procedure is relatively new and is FDA approved option to improve quality of life in patients with symptomatic aortic stenosis for whom the standard valve replacement surgery, which requires an open heart procedure, poses an intermediate or high risk.
Unlike the standard valve replacement surgery, the TAVR that can be done through very small openings and doesn't require a sternotomy.
Most people who have this procedure are in their 70s or 80 and often have other medical conditions that limit their choices for repair of their aortic valve.
The TAVR procedure is performed using four different approaches, allowing the cardiologist or surgeon to choose which one provides the best and safest way to access the valve.
The transfemoral approach is the most commonly employed approach, used in almost 90% of cases. It does not require a surgical incision in the chest, because a sheath (hollow tube) is placed in the femoral artery in the groin.
Other TAVR approaches are conducted under general anesthesia with a breathing tube in place and they include transapical, transaortic, and trans-subclavian approaches.
The transapical approach requires a small incision in the chest and sheath enters through a large artery in the chest or through the tip of the left ventricle (the apex).
In the transaortic approach, the surgeon makes a J shaped incision at the top of the sternum in between the manubrium and the sternum and the sheath is inserted into the opening to the aorta.
The trans-subclavian approach is used more frequently than the transaortic or transapical approaches. In this procedure, an incision is made at the site of either right or left subclavian artery (near the right or left shoulder) and a sheath (hollow tube) is inserted into the opening to the aorta.
The TAVR procedure is not without risks, whether it is a risk of pre-existing conditions or risk of procedure complications, which may include bleeding, blood vessel complications, arrhythmias, kidney disease, stroke, heart attack, infection, and even death.
Because of this, all prospective patients should undergo an assessment before TAVR procedure to measure their risk level.
In December 2015, a team of cardiothoracic surgeons and interventional cardiologists assembled by the Society for Thoracic Surgeons and the American College of Cardiology developed a calculator to estimate a patient's risk for dying in hospital following a TAVR procedure.
The experts used data from more than 20,000 consecutive TAVR procedures to develop this tool, which was based entirely on experience with TAVR patients.
The risk calculator is also available in a form of a free app for iOS and Android mobile devices called TAVR Risk Calculator.
The app makes it easy for clinicians to calculate the in-hospital mortality risk of a prospective patient about to undergo transcatheter aortic valve replacement (TAVR) procedure.
TAVR Risk Calculator app has the similar interface as the other apps made by the American College of Cardiology, such as TreatHF app and LDL-C Manager app, we both reviewed recently on SteadyHealth website.
The app opens to the 'Calculate Risk' tab that allows clinicians to enter patient's relevant criteria, such as patient's demographics (age, gender, and race), patient's pre-procedural characteristics, including renal function, procedure access site, if the patient is class IV of heart failure, if patient has severe chronic lung disease and patient's acuity status.
The renal function requires clinicians to enter glomerular filtration rate, serum creatinine, and whether the patients are on dialysis or not.
Procedure Access Site field has only two entries: femoral and non-femoral for transapical, transaortic, and trans-subclavian TAVR procedures.
The app also allows clinicians to calculate patient's acuity status by allowing them to select the procedure status (elective, urgent, emergency, and salvage), prior cardiac arrest or cardiogenic shock that patient may have had, as well as the use of positive or negative inotropes or mechanical assist device prior to the TAVR procedure.
All entries in the calculator have little 'Info' button beside them, providing more information about a specific entry or parameter.
Based on the data entered/selected, the TAVR Risk Calculator app then provides clinicians with a report showing a predicted in-hospital mortality risk after TAVR procedure, including specific patients risk and national average. This report can instantly be emailed to anyone on the surgery team.
Besides a calculator, the app also provides full guidelines and other references, as well as clinician/patient resources, available in the Resources tab at the bottom of the screen.
Opening these resources will take you outside the app to the JACC website. However, no specific guideline will be displayed, but rather an archive of all online content, which is quite inconvenient.
Overall, TAVR Risk Calculator app is an awesome resource that provides clinicians with quick and evidence-based calculations at the point of care.
Benefit: Cardiothoracic surgeons, interventional cardiologists, and all clinicians who want to calculate the in-hospital mortality risk of patients undergoing the transcatheter aortic valve replacement (TAVR) procedure would benefit from this app