RESULTS
Table 1 includes the demographic and clinical characteristics of groups
1 and 2. The number of cases with a GRACE score higher than 140 was
statistically higher in group 2 than in group 1. When comparing
echocardiography and laboratory parameters for each group, it was
evident that SYNTAX scores and copeptin levels were significantly higher
in group 2 (copeptin: 9.4 vs 28.8 pmol/l, p<0.001; SYNTAX
score: 8 vs 24, p <0.001). Other examined parameters were
similar across both groups (see Table 2).
Serum copeptin levels were significantly higher in patients with ST
segment depression than in those with normal ECG results (13.7 vs 26.9
pmol/l, p<0.001). Serum copeptin levels were higher in the
group with SYNTAX scores above 32 and lower in the group with scores
below 23; all paired comparisons were found to be statistically
significant for the 3 SYNTAX score category. (SYNTAX score<23
vs SYNTAX score 23-32; 11.6 pmol/l vs 30.5 pmol/l, P<0.001;
SYNTAX score<23 vs SYNTAX score >32; 11.6 pmol/l
vs 40.9 pmol/l, p<0.001, SYNTAX score 23-32 vs SYNTAX score
>32; 30.5 pmol/l vs 40.9 pmol/l, p<0.001; see
Figure 2). Similarly, serum copeptin levels were significantly higher
among those with GRACE scores above 140 than among those with lower
GRACE scores (GRACE score<109 vs GRACE score>140;
12.6 pmol/l vs 27pmol/l, p<0.001; and GRACE score 109-140 vs
GRACE score>140; 15.8pmol/l vs 27pmol/l, p:0.002; see
Figure 2). The paired comparison of the group with GRACE scores below
109 and the group with GRACE scores between 109 and 140 was
statistically similar (12.6 pmol/l vs 15.8pmol/l, p:0.114; see Figure
2).
When examining the correlation between serum copeptin levels and CAD
severity, there was a high level of positive correlation between
copeptin levels and SYNTAX scores (r:0.683, p value <0.001).
When the serum copeptin level was used as a predictor of high SYNTAX
scores with a threshold of 18.3 pmol/l, diagnostic sensitivity was found
to be 74.7%, specificity was 83.8%, the positive predictive value was
80.7%, the negative predictive value was 78.6%, and the area under the
curve was 0.795 (see Figure 3).