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Page 2 of 9 Lam et al. Vessel Plus 2019;3:27 I http://dx.doi.org/10.20517/2574-1209.2019.009

Conclusion: The use of TTE-TAVI in conjunction with MAC was not associated with an increased risk of PVL and was
associated with lower hospital resource utilization. However, other factors, such as mode of anesthesia, may have
influenced these findings.

Keywords: Transcatheter aortic valve implantation, transthoracic echocardiography, transesophageal echocardiography

INTRODUCTION
The volume of transcatheter aortic valve implantation (TAVI) has surpassed surgical aortic valve
replacement in Europe and North America [1-3] . Traditionally, TAVI uses general anesthesia (GA)
accompanied by intraprocedural transesophageal echocardiography (TEE) to assess root geometry and
[4]
guide valve placement during the procedure . While rare, TEE can also lead to serious complications such
[5]
as esophageal perforation, aspiration and oropharyngeal damage .
Recently, minimalist TAVI conducted under monitored anesthesia care (MAC) has gained popularity.
Studies suggest that it is less invasive and allows for earlier mobilization and patient discharge without
compromising early outcomes . Since TEE is not usually conducted under MAC, minimalist TAVI
[6]
[5]
often uses transthoracic echocardiography (TTE) instead . Image quality with TTE may be suboptimal
compared to TEE and may have a lower sensitivity in detecting paravalvular leaks (PVL) [5,7-8] . Studies
[8,9]
have shown that PVL after TAVI is often poorly tolerated and associated with excess late mortality .
Thus, understanding whether PVL increases in patients undergoing TAVI with TTE compared to TEE is
paramount. There are few studies directly comparing TTE and TEE in TAVI and the sample size in these
studies are limited. However, there are many studies that compare usage of MAC and GA in TAVI .
[6]
Since TTE and TEE usage is closely associated with the mode of anesthesia, MAC and GA can be used as
surrogate variables for TTE and TEE respectively.

This quantitative meta-analysis aims to compare early echocardiography parameters and safety outcomes
in TTE-TAVI and TEE-TAVI. The primary outcome is PVL and secondary outcomes include 30-day
mortality, renal failure, stroke, major bleeds, hospital length of stay (LOS), ICU LOS, fluoroscopy time,
contrast volume and procedure time.

METHODS
Systematic literature review
Ovid versions of Medline and Embase were searched from 1946 to June 18, 2018 for the following key
terms: “Transcatheter aortic valve implantation,” “echocardiography” and “anesthesia”. The full search
strategy is shown in Supplementary Appendix S1. Inclusion criteria included the following: English,
comparison of TTE to TEE or MAC to GA in TAVI, reported at least 1 chosen outcome. MAC vs GA
papers must also specify the frequency of TTE and TEE usage. Exclusion criteria included the following:
non-English studies, conference abstracts, proceedings, case reports and other non-comparative study
designs. The citations from the literature search were compared to papers in a meta-analysis comparing
[6]
MAC to GA in TAVI to ensure papers were not missed .

All titles and abstracts were reviewed. Full papers of citations that could potentially be included in the
study were further analyzed. The literature search results were reviewed independently by 2 investigators
(T.L. and A.D.). Disagreements were discussed by investigators until an agreement was reached.

Quality assessment and data abstraction
Quality of studies were assessed with the Grading of Recommendations Assessment, Development and
[10]
Evaluation approach . The following outcomes were abstracted: usage of TTE, usage of TEE, mild PVL,