Methodological quality
The average overall quality rating was 0.81 ± 0.53, with ratings ranging
from 0 to 1.81. Appendix A illustrates the average scores on
the elements of the checklist. The analysis revealed lower scores
related to the internal validity for both bias and selection bias, and
for power analysis, which is related to the quality of reporting. The
low values shown are due to the study type being a retrospective with no
randomized samples validity studies. Acceptable interrater agreement was
found (κ = 0.89; %‐agree = 94.9).
Follow up
The mean follow up period, calculated in 9 papers, was 35.66 [27.50-
43.81] months 14-18,20,21,25,26. The longest follow
up period was 55.2 months 17. Follow up was 100%
complete in 9 studies 14-17,19,20,23-25.
Main endpoints
Figure 2A shows that the
log IRR of survival between AVR group and noAVR group was 0.58 [0.28,
0.87] (p-value = 0.0001; I-square = 24.16%, p-value = 0.25; Egger’s
test: 0.18 [-0.18, 0.55], p-value = 0.002). This suggests that the
overall survival is significantly better in the AVR group compared to
the noAVR group. The funnel plot is shown in Figure 2B (funnel
plot asymmetry test: p-value = 0.10). Moreover, the meta regression
revealed that low LVEF is related to higher survival rates in the AVR
group (p-value = 0.04) when compared to preserved LVEF (Figure
3A ). Conversely, LVEF has no impact on survival in the noAVR group
(p-value = 0.18), as shown in Figure 3B .