Sandbox:tavr

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. [2]

Transcatheter Aortic Valve Replacement (TAVR) Procedure Guide Microchapters
Overview
Causes
FIRE
Diagnosis
Treatment General Approach Choice of Intervention Type of Valve and Discharge Anticoagulation Therapy
Do's
Don'ts

Overview

During the past 50 years, surgical aortic valve replacement (SAVR) was the standard of care for patients with severe AS. Global aging has raised concerns about safety and possibility of surgical procedure in old patients with associated co-morbidities. 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.
Preoperation evaluation, selecting the appropriate imaging modality, issues in TAVR procedure and patient follow up are the areas of more focused importance.
We will describe these factors based on the recent expert consensus for TAVR procedure.

Definition

The most important step is to define the severity of AS and appropriate patient that need TAVR. Severe sypmtomatic (Stage D) AS is considered as TAVR candidate.

Severe symptomatic AS (stage D)
STAGE	DEFINITION	SYMPTOMS	VALVE ANATOMY	VALVE HEMODYNAMICS	HEMODYNAMIC CONSEQUENCES
D1	Symptomatic severe high-gradient AS	Exertional dyspnea or decreased exercise tolerance Exertional angina Exertional syncope or presyncope	Severe calcification or congenital stenosis with severely reduced opening	Vmax ≥ 4 m/s or mean ΔP ≥ 40 mmHg AVA ≤ 1.0 cm² but may be larger with mixed AS and AR	LV diastolic dysfunction Left ventricular hypertrophy May present with pulmonary hypertension
D2	Symptomatic severe low-flow/low gradient AS with reduced LVEF	Heart failure Angina Syncope or presyncope	Severe calcification or congenital stenosis with severely reduced leaflet motion	AVA ≤ 1.0 cm² with resting aortic Vmax < 4 m/s or mean ΔP ≥ 40 mmHg Dobutamine stress echo shows AVA ≤ 1.0 cm² with Vmax ≥ 4 m/s at any flow rate	LV diastolic dysfunction Left ventricular hypertrophy LVEF <50%
D3	Symptomatic severe low gradient with normal LVEF	Heart failure Angina Syncope or presyncope	Severe calcification with severely reduced leaflet motion	AVA ≤ 1.0 cm² with Vmax < 4 m/s or mean ΔP ≤ 40 mmHg AVA ≤ 0.6 cm² Stroke volume index < 35 mL/m²	Increased LV relative wall thickness Small LV chamber with low stroke volume Restrictive diastolic filling LVEF ≥ 50%

Risk Assessment

Underlying risk for SAVR is basic component to consider patient for TAVR. This risk assessment is based on several components that include:

• The Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score. To calculate this score please click here.

• Frailty
• Main organ system dysfunction
• Procedure-specific impediments

SAVR risk assessment
Risk Stage	Low Risk (Must meet ALL criteria in This column)	Intermediate Risk (Any 1 criterion in this column)	High Risk (Any 1 criterion in this column)	Prohibitive Risk (Any 1 criterion in this column)
STS PROM	<4%	4% to 8%	>8%	Predicted risk with surgery of death or major morbidity (all-cause) >50% at 1 y
Frailty†	None	1 Index (mild)	≥ 2 Indices (moderate to severe)	Predicted risk with surgery of death or major morbidity (all-cause) >50% at 1 y
Major organ system compromise not to be improved postoperatively‡	None	1 Organ system	No more than 2 organ systems	≥ 3 Organ systems
Procedure specific impediment	None	Possible procedure specific impediment	Possible procedure specific impediment	Severe procedure specific impediment