Updating guidelines: When is the best timing of upgrading recommendation for an emerging technology?

Abstract

There have been many emerging technologies and devices to treat valvular heart diseases in recent years. Some of the devices which showed promising and favorable outcomes in a small human study came into a large clinical trial. In 2002, Dr. Alain Cribier performed the first successful percutaneous aortic valve replacement on an inoperable patient. Since then, transcatheter aortic valve implantation (TAVI) has been expanding to a choice of treatment of aortic valve stenosis (AS) by conducting a large-scale randomized clinical trial in prohibitive risk, high-risk, intermediate risk, and low risk patients. In 2017, American College of Cardiology (ACC)/ American Heart Association (AHA) issued a “Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease.” In this focused update, TAVI is recommended for symptomatic patients with severe AS (Stage D) and a prohibitive risk for surgical aortic valve replacement (SAVR) with Class of Recommendation (COR) 1 and Level of Evidence (LOE)-A, and SAVR and TAVI are equally recommended for symptomatic patients with severe AS and high surgical risk with COR 1 and LOE-A. ACC/AHA issued a new version of “2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease” in December 2020, in which much stronger recommendations favoring TAVI were documented. In the synopsis of the newest guideline, the writing group mentioned that “in patients considering a bioprosthetic AVR, the next step is the choice between SAVR and TAVI.” Because the bioprosthetic valve is recommended for SAVR in patients aged over 65 years, they seem to hypothesize that bioprosthesis and TAVI valve, both of which are constructed using xenogeneic pericardium, are equivalent in all required aspects. The following is a new recommendation graded as COR 1 and LOE-A: “For symptomatic patients with severe AS who are 65 to 80 years of age and have no anatomic contraindication to transfemoral TAVI, either SAVR or transfemoral TAVI is recommended after shared decision-making.” Referenced articles to support this recommendation are surprisingly the same as those used in the previous 2017 focused update. The average age of the patient populations (TAVI vs. SAVR) in all of the above referenced studies is over 80. Why did the writing group upgrade the strength of recommendation of TAVI without new supporting studies? There is another bold recommendation: “For symptomatic patients with severe AS who are >80 years of age or for younger patients with a life expectancy <10 years and no anatomic contraindication to transfemoral TAVI, transfemoral TAVI is recommended in preference to SAVR.” The writing group admits that robust durability data for TAVI currently extend to at longest only five years and SAVR valve deterioration typically occurs after >10 years. There is no supporting evidence at all that a patient with a life expectancy <10 years is suitable for the device with a possible five-year durability. It is hard to understand the reason why the writing group recommends TAVI over SAVR in patents over 80 years of age without any conditions who may have a longevity longer than five years and those whose life expectancy less than 10 years but possibly more than five years. Ten-year-long TAVI durability data must be provided when a very sensitive lifespanrelated phrase like “life-expectancy <10 years” is considered. In this issue of the Asian Annals, the writing group of The Latin American Association of Cardiac & Endovascular Surgery (LACES) Statement expressed great concerns on too strong recommendations for TAVI for AS in a certain subset of patients They stated that the previous AHA/ACC Guidelines for the Management of Patients with Valvular Heart