3.2.2. Secondary outcomes: early and long-term mortality, need of
interventional procedures and surgical re-interventions
In all 32 studies included in the meta-analysis only 6 early deaths were
reported among 1191 patients.
Pooled prevalence of early
mortality after CABG was 0.28%
(95% CI: 0.00-0.73%, I²=0%, tau²=0, Supplementary Figure 5).
26 studies reported interventional procedures and surgical
re-interventions rates: 63/1108 and 56/1108 patients underwent
interventional procedures and surgical re-interventions at follow-up
(mean 110.35 months, 95% CI: 28.50-264.00 months), respectively. Pooled
prevalence of interventional
procedures was 3.97% (95% CI: 1.91-6.02%, I²=60%, tau²=0.0008,
Supplementary Figure 6). Across the studies that reported interventional
procedures, high heterogeneity demonstrated elevated variability across
the included studies.
Pooled prevalence of surgical
re-interventions was 3.47% (95%
CI: 2.26-4.68%, I²=5%, tau²<0.0001, Supplementary Figure 7).
Patients treated with arterial, venous and mixed (arterial plus second
venous graft) CABG were compared to assess long-term
mortality. 8 arm level papers out
of 32 studies were included to perform the network meta-analysis [31,
34, 39, 41-43, 49, 53]. Mean follow-up across studies for long-term
mortality was 142.56 months (follow-up: min 48 – max 264 months).
Survival at follow-up after arterial, venous and mixed CABG are
99.07±2.27%, 83.33%±28.87% and 99.87±0.33%, respectively. The
network model, trace plot and density plot for long-term mortality are
shown in Supplementary Figures 8 and 9. Summary results are shown in
Figure 4A, while rank probability analysis are demonstrated in Figure
4B.
The efficacy of different treatments using HR and corresponding 95% CrI
is displayed in Supplementary Figure 10. Pairwise comparisons at
follow-up are shown in Supplementary Figure 11 A-C. There is a lack of
evidence to suggest inconsistency within the network model
(Supplementary Figure 12). Briefly, mixed CABG (HR 0.03, 95% CrI:
0.00-0.30) and arterial CABG (HR 0.13, 95% CrI: 0.00-1.78) showed
reduced long-term mortality compared with venous CABG.
More in deep, focusing the comparison between long-term mortality for
Arterial CABG vs Mixed CABG we are faced with 58 single CABG out of a
total of 133 cases (43.6%) in which at least one arterial conduit has
been employed(Supplementary Figure 11C) [34,39,41-42,49]. It appears
that the use of arterial conduit, even better if applied in a multiple
CABG setting, provides long-term mortality benefit. These findings need
to be confirmed in future studies.