Outcomes of transcatheter aortic valve replacement in mixed aortic valve disease

Selected in JACC: Cardiovascular Interventions by B. Ezhumalai , S. Brugaletta

This study compared the outcomes of TAVR in patients with pure Aortic Stenosis (i.e., without or trivial AR) vs. patients with MAVD (AS associated with mild to moderate or severe AR).

Reviewers

Babu Ezhumalai

@Babu_Ezhumalai

Interventional cardiologist / Cardiologist

Fortis Malar Hospital - Tamil Nadu, India

Salvatore Brugaletta

@sbrugaletta

Interventional cardiologist / Cardiologist

Barcelona, Spain

Our Comment

This joint review is part of the PCRonline GLOBAL Journal Club Initiative by selected members of the EAPCI/PCR Journal Club and EAPCI young ambassadors, and is based on the underlying idea of “Bringing peers together, exchanging ideas, towards a common standard of care”.

Why this study – the rationale/objective?

Transcatheter aortic valve replacement (TAVR) has been widely accepted for treating patients with severe aortic stenosis (AS). In patients with mixed aortic valve disease (MAVD) guidelines recommend individualised treatment approach based on the predominant native lesion. There are not sufficient data available in the literature with regard to safety and efficacy outcomes of TAVR in MAVD patients.

How was it executed – the methodology?

This study compared the outcomes of TAVR in patients with pure AS (i.e., without or trivial AR) vs. patients with MAVD (AS associated with mild to moderate or severe AR). Patients who underwent transfemoral TAVR of native aortic valve between January 2014 and December 2017 were included in this study.

Patients were divided into two groups based on the presence of baseline pre-TAVR AR into pure AS (no or trivial AR) and MVAD (AS with associated mild, moderate, or severe AR). The primary outcome was all-cause mortality adjusted to account for post-TAVR AR development in both groups. The secondary outcomes included composite endpoints of early safety and clinical efficacy as specified in the Valve Academic Research Consortium-2 criteria.

What is the main result?

• A total of 1,133 patients were included in this study and followed-up for a median duration of 27 months; median age was 83 years, 43% were women
• 688 patients (61%) had MAVD in this study
• Overall 17% developed mild, 2% moderate, and <1% severe post-TAVR AR.
• Kaplan-Meier curves showed better overall survival in patients with MAVD group compared with those with pure AS group (p=0.03).
• MAVD group had a higher prevalence of post-TAVR AR than pure AS group (22.1% vs. 14.4%; p = 0.001).
• Among patients who developed post-TAVR AR, MAVD group had better survival (p = 0.04).
• On the contrary, the presence of pre-TAVR AR did not improve survival in patients who did not develop post-TAVR AR (p = 0.11).
• The secondary outcomes were statistically comparable between the two groups.

Critical reading and relevance for clinical practice

In this study, it was found that among patients who underwent TAVR treatment those with MAVD had better survival compared with those with pure AS. In particular the survival was better in those patients who developed a post-TAVR AR.
It is easy to think that patients with pre-existing AR undergoing TAVR treatment may tolerate better a mild post-procedural AR than those without pre-procedural AR. This can be explained by the left ventricular adaptation to AR: in patients with pure AS, there is pressure-induced concentric hypertrophy of the left ventricle (LV) with subsequent development of diastolic dysfunction and reduction in compliance; these make the LV less likely to tolerate post-TAVR AR. On the contrary, pre-existing AR results in volume overload leading to dilatation, eccentric hypertrophy and remodelling of LV. Thus, it is easier for the LV in patients with a larger pre-procedural end-diastolic volume to tolerate post-TAVR AR and their outcomes are better.

This study included the largest cohort of patients with MAVD reported till date. The better survival outcomes seen in MVAD undergoing TAVR treatment reported in this study have not been satisfactorily reported with surgical aortic valve replacement (SAVR) or AV repair.
The main limitations of this analysis are that it is a single-center retrospective observational study and only patients undergoing TAVR through transfemoral approach were included.

A systematic analysis of 13,289 cases in India revealed that isolated AS was present in 7.3% of cases and combination of AS+AR occurred in 12.7% of cases. There is no data available regarding the outcomes of TAVR in patients with MVAD in India.