1Universitätsklinikum Schleswig-Holstein Innere Medizin III mit den Schwerpunkten Kardiologie, Angiologie und internistische Intensivmedizin Kiel, Deutschland; 2Universitätsklinikum Schleswig-Holstein Klinik für Herz- und Gefäßchirurgie Kiel, Deutschland
Introduction
Transcatheter aortic valve replacement (TAVR) is an established method for the treatment of high-risk inoperable patients with severe symptomatic aortic valve stenosis (AS) [1]. While AS is the most treated valve disease in the western world, up to 20 % of patients with AS simultaneously suffer from concomitant relevant mitral regurgitation (MR), leading to a worse patient prognosis and higher mortality [2, 3]. The primary objective of this study was to assess the change in MR severity of MR in patients with severe AS undergoing TAVR and its influence on patient survival.
Methods
Study population
This retrospective study, approved by the local ethics committee, investigated patients who were treated with a transfemoral TAVR at the University Hospital Schleswig-Holstein, Campus Kiel between March 2009 and February 2018. We divided our study population into two groups according to baseline MR (defined according to the American Society of Echocardiography recommendations) [4]. One group of patients with MR ≤ Grade 2, referred to as non-significant MR “nr-MR”. The other group of patients with a higher grad of MR (MR ≥ Grade 3) referred “high-MR”.
Results
Baseline characteristics
In our analysis, 820 patients who underwent TAVR were included. Patient characteristics are summarised in Table 1.
Table I Baseline characteristics (SHORT)
|
Total |
nr-MR |
r-MR |
p | |
|
Characteristic |
(n = 820) |
(n = 642 / 78 %) |
(n = 178 / 22 %) |
|
|
Male sex |
373 (45.5) |
308 (48.0) |
65 (36.5) |
0.01 |
|
Pre-existing conditions | ||||
|
AF |
357 (43.6) |
259 (40.4) |
98 (55.1) |
<0.01 |
|
Pre-existing conditions |
|
|
|
|
|
Mean Hs-TnT [ng/l](SD) |
73.7 (454.6) |
68.2 (478.7) |
95,5 (344.8) |
< 0.01 |
|
Mean NT-proBNP [ng/l] (SD) |
4131.4 (7473.0) |
3577.8 (7108.7) |
6249.3 (8427.9) |
< 0.01 |
|
Echocardiography parameters at baseline |
|
|
|
|
|
LV ejection fraction |
|
|
|
< 0.01 |
|
< 35 % |
70 (8.5) |
47 (7.3) |
23 (12.9) |
0.02 |
|
≥ 55 % |
422 (51.5) |
347 (54.0) |
75 (42.1) |
< 0.01 |
|
Mean sPAP (mmHg) (SD) |
45.8 (14.6) |
52.6 (15.6) |
43.8 (13.6) |
< 0.01 |
|
Risk Scores |
|
|
|
|
|
STS Score (%) mean, SD |
5.5 (3.7) |
5.4 (3.6) |
6.1 (3.8) |
0.02 |
AF=HsTnT: Highly sensitive troponin-T, NT-proBNP: N-terminales pro brain natriuretic peptide, sPAP: systolic pulmonary artery pressure
Postprocedural remodelling: Change in MR and cardiac function
Overall, there was a significant reduction in MR in pre- and 7-day post procedural measurement (p < 0.01). This reduction was mainly driven by the r-MR group (p < 0.01). Mean MR grade for the r‑MR group declined as an overall class switch from moderate to mild (p < 0.01). There was a significant difference in pairwise comparison resulting in significant more patients with MR improvement among the group of r‑MR. Among the cohort of improved MR (n = 167) patients showed a significant reduction in NT-proBNP (p = 0.03) and sPAP (p < 0.01).
Survival after TAVR
Maximum follow-up duration was 10.5 years and median follow up duration was recorded for 3.4 years. Death was recorded for 299 patients (36.5 %). There was no difference in mortality for patients in r-MR vs. nr-MR (p = 0,35) and no difference in survival for patients with improved MR (p = 0,80).
Conclusion
TAVR can significantly reduce MR, in particular in those patients with moderate to severe MR. This effect was significant among echocardiographic and cardiac biomarkers. We could not prove a significant effect on long-term mortality regarding MR reduction. The knowledge that a higher-grade MR could improve so comprehensively suggests a stepwise approach by TAVR followed by close meshed follow-up.