**5. Risk stratification**

*Aortic Stenosis - Current Perspectives*

stenosis

symptoms during exercise testing

**Early elective surgery is indicated in asymptomatic patients with** [8]:

• depressed LV function not due to other causes and in patients who develop

• abnormal exercise test showing symptoms on exercise clearly related to aortic

• abnormal exercise test showing a decrease in blood pressure below baseline

• predictors of symptom development and adverse outcomes: clinical characteristics (older age, presence of atherosclerotic risk factors), echocardiographic parameters (valve calcification, peak aortic jet velocity, LVEF, rate of hemodynamic progression, increase in mean gradient >20 mmHg with exercise, excessive LV hypertrophy, abnormal longitudinal LV function, and pulmonary hypertension), and biomarkers (>threefold age- and sex-corrected normal range).

• When early elective surgery is considered in patients with normal exercise performance because of the presence of such outcome predictors, the operative risk should be low. In patients without predictive factors, watchful waiting

An update of proposed management strategy for patients with severe AS by Leal et al. [17] is shown in **Figure 1**, based on the ESC/EACTS and ACC/ AHA guidelines

*Management of severe aortic stenosis [8, 17, 18]. ACC/AHA recommendations have been shown in parentheses.*

appears safe and early surgery is unlikely to be beneficial.

on the management of valvular heart disease [8, 18].

**34**

**Figure 1.**

Risk stratification applies to any sort of intervention and is required for weighing the risk of intervention against the expected natural history of VHD as a basis for decision making [8]. Nowadays, the STS score and logistic EuroSCORE II are the most commonly used. **The EuroSCORE I** overestimates operative mortality and its calibration of risk is poor, and *it should no longer be used to guide decision making,* but it has been used in many TAVI studies/registries and may still be useful to identify the subgroups of patients for decision between intervention modalities and to predict 1-year mortality [8]. **The EuroSCORE II** and the **Society of Thoracic Surgeons (STS)** scores more accurately discriminate highand low-risk surgical patients and show better calibration to predict postoperative outcome after valvular surgery [8]. Current models do not include some risk factors that may be particularly important in the prediction of outcomes, including frailty, pulmonary hypertension (PH), porcelain aorta, and the presence of hepatic dysfunction.

New scores have been developed to estimate the risk of 30-day mortality in patients undergoing TAVI, with better accuracy and discrimination, but not without certain limitations by a lack of consideration of frailty, disability, and cognitive function [19]. Examples of those are: FRANCE-2 risk score [20], the STS/ ACC TVT registry predictive model [21], and the TAVR risk score based on data from the German aortic valve registry [22]. A new tool based on the STS/ACC TVT Registry™ is an application for from the STS/ACC TVT Registry™ an application for mobile devices and web, call **"TAVR in-hospital mortality Risk app**" [23], in order to inform physicians of the estimated risk of in-hospital mortality.

It remains essential not to rely on a single risk score figure when assessing patients or to determine unconditionally the indication and type of intervention.

*The role of the heart team* is essential to take all of these data into account and adopt a final decision on the best treatment strategy. It is important to take into account patient's life expectancy, expected quality of life, and patient preference, as well as local resources, in order to do a proper planning of intervention. There is a growing interest in the assessment of frailty, an overall marker of impairment of functional, cognitive, and nutritional status. Frailty is associated with increased morbidity and mortality after surgery and TAVI [24].

Finally, the patient and family should be thoroughly informed and assisted in their decision on the best treatment option.

Actual **AHA/ACC guideline** classifies patients with severe AS into *four global risk categories*: [19].


Thus, the current **ESC/EACTS guidelines** for the management of valvular heart disease [8] consider *two global risk categories*:


A resume of risk categories is shown in **Table 2**.


*\*ESC/EACTS guidelines consider two categories (low and increased surgical risk). Based on 2017 ACC Expert Consensus Decision Pathway for Transcatheter Aortic Valve Replacement in the Management of Adults with Aortic Stenosis and the 2017 ESC/EACTS Guidelines for the management of valvular heart disease [8, 19, 25].*

#### **Table 2.**

*Risk assessment tools.*

In conclusion, the decision to proceed with AVR or TAVI requires careful weighing of the potential for improved symptoms and survival and the morbidity and mortality of surgery and should be made by the heart team according to the individual patient characteristics. Checklist for choice of therapeutic intervention option (**Table A1**) could be consulted and printed from the additional material, in order to provide aspects that should be considered for the individual decision, based on the current recommendation of de ESC/EACTS guidelines.
