DOI DOI https://doi.org/10.1007/s00392-021-01843-w
Background: The outcome of patients with low-gradient (LG) aortic stenosis after transcatheter aortic valve replacement is not well evaluated. Long-term clinical success is thought to be less pronounced in LG patients compared to patients with high gradient (HG) aortic stenosis. The objective of the study was to characterise different LG groups and determine their outcome after TAVR.
Methods: All patients undergoing TAVR for severe aortic stenosis at our centre between 2013 and 2019 were included in the study. Preinterventional echocardiography has been reassessed and patients have been divided into four groups according to mean pressure gradient (dPmean), ejection fraction (EF), and stroke volume index (SVi). Patients with a dPmean <40 mmHg were split into classical low-flow (EF <50%) LG (cLFLG), paradoxical low-flow (EF ≥50%, SVi ≤35 ml/m2) LG (pLFLG), and normal-flow LG (EF ≥50%, SVi >35 ml/m2, NFLG). Patients with previous aortic valve replacement or severe aortic regurgitation were excluded from the analysis.
Results: 1581 patients were analysed (mean follow-up 1.73 years). Baseline characteristics differed, among others, in sex, rate of atrial fibrillation, coronary artery disease, and higher-grade mitral regurgitation (see Table). Rates of periprocedural complications including death, device failure, pericardial effusion, stroke or myocardial infarction were similar.
Survival rates at two years differed significantly (Log-rank test, <0.001): HG, 81.1% [95% confidence interval, 77.6-84.7%], cLFLG, 65.7% [59.6-72.4%], pLFLG, 68.3% [61.5-75.9%], and NFLG, 76.9% [71.0-83.4%] (see Figure). Corresponding hazard ratios in comparison to HG patients were 2.18 [95% CI, 1.62-2.94], p<0.001, for cLFLG, 2.00 [95% CI, 1.44-2.78], p<0.001, for pLFLG, and 1.38 [95% CI, 0.97-2.00], p=0.078, for NFLG. Similar results were obtained when adjusting for Society of Thoracic Surgeons (STS) Score and after propensity score matching.
Conclusion: In this all-comer analysis, more than half of the patients belong into LG groups with considerable differences in patient characteristics. While equally safe during the procedure, all LG groups are associated with increased 2-year mortality rates compared to patients with HG aortic stenosis. Further studies evaluating this are needed.
Table: Patient characteristics
|
|
HG |
cLFLG (N=320, 20.2%) |
pLFLG (N=263, 16.6%) |
NFLG (N=275, 17.4%) |
p value |
|
Male sex |
331 (45.8%) |
222 (69.4%) |
107 (40.7%) |
123 (44.7%) |
< 0.01 |
|
Age |
81.3 [77.2-85.6] |
82.0 [77.2-86.6] |
82.2 [78.2-85.6] |
80.7 [76.3-85.6] |
0.17 |
|
STS Score |
3.4 [2.1-5.7] |
4.8 [3.0-7.2] |
4.0 [2.6-6.2] |
3.5 [2.1-5.6] |
0.06 |
|
Diabetes |
200 (30.0%) |
109 (36.3%) |
89 (36.0%) |
76 (29.1%) |
0.08 |
|
Hypertension |
601 (89.7%) |
280 (93.3%) |
226 (91.5%) |
244 (92.4%) |
0.25 |
|
Atrial fibrillation |
151 (20.9%) |
120 (37.5%) |
114 (43.3%) |
58 (21.1%) |
< 0.01 |
|
Coronary artery disease |
394 (58.5%) |
230 (75.4%) |
159 (64.6%) |
166 (63.4%) |
< 0.01 |
|
Chronic kidney disease |
304 (42.0%) |
210 (65.6%) |
140 (53.2%) |
116 (42.2%) |
< 0.01 |
|
EF (%) |
55.0 [52.1-58.0] |
40.0 [35.0-45.0] |
55.0 [55.0-58.0] |
55.0 [55.0-60.0] |
< 0.01 |
|
SVi (ml/m2) |
37.7 [31.2-45.8] |
27.2 [21.8-32.8] |
29.5 [25.7-32.4] |
41.3 [37.6-45.7] |
< 0.01 |
|
Aortic valve aperture (cm2) |
0.7 [0.5-0.8] |
0.8 [0.6-0.9] |
0.7 [0.6-0.8] |
0.9 [0.8-0.9] |
< 0.01 |
|
dPmean (mmHg) |
48.0 [43.0-56.0] |
26.0 [20.0-31.2] |
28.0 [23.0-34.0] |
33.0 [28.0-36.0] |
< 0.01 |
|
Mitral regurgitation (>moderate) |
47 (6.5%) |
32 (10.0%) |
12 (4.6%) |
9 (3.3%) |
< 0.01 |
|
Tricuspid regurgitation (>mild) |
140 (19.4%) |
76 (23.8%) |
62 (23.6%) |
32 (11.6%) |
< 0.01 |
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