Mortality
In-hospital mortality figures were given for 10 out of the 11
comparative studies found2,15,20,44-51. None stated a
significant difference in mortality rates between Witnesses and
non-Witnesses. Witness in-hospital mortality rate in the comparative
studies varied between 0 and 18.8%. These figures are similar to those
found in non-comparative studies, which ranged from 0 to
14.3%8,16,29,43,52,53,57. One study by Ramiaramananaet al 53. split the 153 Witness study
population into low and high risk patients using their co-morbidities.
Of the 13 classed as high risk, 3 died (23%), which was significantly
higher than those in the low risk group (3 of 140 (2.1%),
p=0.001)53. Jassar et al. 52compared mortality rates in Witnesses undergoing elective versus urgent
surgery, showing the mortality rate was higher in the elective surgery
group (5 vs 0, respectively), although the difference was not
significant (p=1.0). This study suggests urgent surgery can be carried
out on Witnesses with low risk, despite no preoptimization of Hb levels.
30 day mortality was reported in a number of studies. Only three of the
11 comparative studies reported the data, but of the three studies, no
difference in rates was found44,46,49. Again,
non-comparative studies found similar results (comparative: 0 to
3.06%44,46,49; non-comparative 0 to
5%4,16,43,57). Vaislic et al. reported a drop
in 30 day mortality with time, stating 3% in those operated on between
1991-2003 and 1% for those between 2003-201216. They
account for this by better techniques and optimisation preoperatively. A
study by Ott and Cooley in 1977 found a 30 day mortality rate of
9.4%61, but this study was more than 40 years ago and
also did not distinguish between outcomes for adults and children, which
may account for the higher percentage seen.
Longer term survival rates were reported in few studies, with only one
of the comparative studies sharing this outcome. Pattakos et al.reported survival estimates of Witnesses were 86%, 69%, 51%, and 34%
at 5, 10, 15, and 20 years after surgery, respectively, vs 74%, 53%,
35%, and 23% for non-Witnesses, showing Witnesses had better survival
rates15. Jassar et al. stated the 1 and 5 year
survival rates for Witnesses after cardiac surgery to be 87.3%±3.4 and
76.1%±5.4, respectively52. The 5 year survival rates
reported for those undergoing CABG only were reported to be 90.3%.