TAVR vs SAVR

# Overview
Until recently, aortic valve replacement (AVR) was the only effective treatment for severe symptomatic aortic stenosis. Global aging has raised concerns about safety and possibility of surgical procedure in old patients with associated comorbidities. Transcatheter aortic valve replacement (TAVR) created a new era of safety for this population and enabled physicians to replace the stenotic valve with more certainty. In TAVR, also known as Percutaneous Aortic Valve Replacement (PAVR), a synthetic valve is advanced to the heart through a small hole made in groin. This procedure is similar in its mechanism to the insertion of a stent, or performing balloon angioplasty albeit with much larger equipment. Traditional aortic valve replacement is an invasive surgical procedure, with considerable mortality and morbidity, especially in more fragile patients. In the newly developed TAVR procedure, the dysfunctional aortic valve is replaced percutaneously, which obviates the need for open heart surgery.Patient selection, selecting the appropriate imaging modality, preprocedure evaluation, selecting the appropriate valve type and valve size, post procedure complications and long term follow-up are the main areas of focused importance.

# Comparing TAVR and SAVR
- Surgical Aortic Valve Repair (SAVR) is the traditional way of treating a stenotic aortic valve.
- In the last decade, TAVR has emerged as a viable option for patients at high surgical risk or at high risk for post-surgical complications.

## Evidence
Systematic reviews have addressed this comparison in patients deemed to be low-risk (Society of Thoracic Surgery (STS) risk score uropean System for Cardiac Operative Risk Evaluation (EuroSCORE) II less than 4%.):
- "In patients with severe aortic stenosis and coronary artery disease, TAVR + PCI was associated with greater all-cause mortality at follow-up compared with SAVR + CABG."
- "Among older low-risk patients with severe aortic stenosis, TAVR is associated with a lower rate of death or disabling stroke compared with SAVR"
The Cochrane Collaboration reviewed the following trials of low-risk patients in 2019:
- Popma (Evolut)  1468 patients
- Thyregod (NOTION) 280 patients
- Mack (PARTNER 3). 1000 patients
After the Cochrane review, a systematic review by Kheiri in 2020 of low risk patients included the same three trials and added:
- Nielsen (STACCATO), 2012 The Cochrane had handled this trial separately due to the trial having "utilised the less contemporary transapical TAVI and was prematurely terminated due to an excess of adverse events in the TAVI group." The Cochrane had excluded this trial because "all study participants were deemed intermediate risk according to the study investigators."
- Serruys (SURTAVI) 2018
Other randomized controlled trials with increased surgical risk:
- Leon (PARTNER 2)
- Adams (US PIVOTAL - CoveValve)
Non-randomized studies:
- Thourani (SAPIEN 3)

## 2014 AHA/ACC Guidelines for the Management of Patients With Valvular Heart Disease Recommend the Following:
- In the recent years, terminology has arose to define patients who qualify for TAVR as "inoperable patients" who are at > 50% risk of mortality at 30 days after a potential SAVR procedure.
- There is much debate regarding the subjective nature of defining a patient as "inoperable"; however, the heart valve team should collaborate to determine the optimal procedure for the patient.
- TAVR has demonstrated up to a 20% risk reduction in all-cause-mortality at 12 months which is sustained for up to 5 years post-procedure, when compared to SAVR.
- In high risk patients such as the elderly and those with a NYHA III or IV functional status, TAVR has shown non-inferiority to the traditional SAVR procedure and regardless of the procedure undertaken, patients maintained a NYHA I or II functionality for up to 5 years post-procedure.
- It is noteworthy to say that TAVR is associated with a significant and sustained reduction in risk of ischemic stroke for 30 days and up to 2 years after the procedure compared to surgery.
- Nevertheless, SAVR continues to play a role in patients who require an aortic valve replacement with lower surgical risk.

## 2017 ESC/EACTS Guidelines for the Management of Patients With Valvular Heart Disease Recommend the Following:

# Future Perspectives
- TAVR has transformed the treatment and the way of dealing with symptomatic patients suffering from aortic stenosis, particularly in those who are at high risk or inoperable for surgical aortic valve replacement (SAVR).
- When it successfully performed, TAVR returns the patient to a good prognosis and favorable life style.
- It is estimated that 25,000 TAVR procedures were done in the U.S in 2015 and an increase in this number is anticipated because of increase in the number of the elderly population.
- In the United States, the elderly population will reach 50 million by 2019 and this old population is highly vulnerable to degenerative valve disease.
- The future of TAVR will be focusing on more technical aspects; trying to reduce the device profile, enhancing it's positioning, retrievability and promoting valve durability with anticalcification treatments.
- In the last decade, clinicians remained focused on demonstrating efficacy and safety of the procedure. In latter years, the minimalist approach to the deployment of the valves has become the mainstay of advancements in the TAVR procedure.
- Examples include the avoidance of general anesthesia and the utilization of conscious sedation whenever possible, the reduction of reliance or use of transesophageal echocardiography (TEE), the reduction or elimination of balloon pre-dilatation of the stenosed valve, as well as early discharge programs.
- With ongoing clinical trials and further advancements in valve technology, TAVR will establish an expanded indication in patients with moderate to severe aortic stenosis.