## 4 Results  
### Demographics of the Study Population  
Table 1 presents the patients' demographic characteristics and underlying diseases who underwent 3-vessel PCI for the first time. Patients who fulfilled the criteria from 1 January 2007 to 31 December 2009 were selected from the NHIRD. The mean follow-up periods were approximately 12 years in the survival group and approximately five years in the death group (\(p<0.001\)). Men had a higher survival rate (\(p<0.001\)). \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & & \multicolumn{2}{c}{**PCI (n = 2337)**} & \multicolumn{1}{c}{_p-Value_} \\ \cline{3-5}
**Variables** & \multicolumn{2}{c}{**Survive**} & \multicolumn{2}{c}{**Death**} \\  & \multicolumn{2}{c}{**(n = 1188)**} & \multicolumn{2}{c}{**(n = 1149)**} \\ \cline{3-5}  & \multicolumn{2}{c}{**N (\%)**} & \\ \hline \multicolumn{5}{c}{Survival time (mean, SD) in years} & 11.34 (0.87) & 4.57 (3.51) & \textless{}0.001 \\ \hline \multicolumn{5}{c}{Baseline} \\ \hline X1 & Sex & Male & 941 (79.21) & 765 (66.58) & \\  & Female & 247 (20.79) & 384 (33.42) & \textless{}0.001 \\ \hline X2 & Age (mean, SD) & 60.09 (10.18) & 71.18 (10.24) & \textless{}0.001 \\ \hline \multirow{5}{*}{X3} & \multirow{5}{*}{CCIS stratified} & 0 & 185 (15.57) & 58 (5.05) & \\  & & 1 & 340 (28.62) & 134 (11.66) & \\  & & 2 & 284 (23.91) & 197 (17.15) & \\ \cline{3-5}  & \multirow{2}{*}{CCIS stratified} & 3 & 180 (15.15) & 193 (16.8) & \textless{}0.001 \\  & & 4 & 90 (7.58) & 165 (14.36) & \\  & & 5 & 47 (3.96) & 136 (11.84) & \\  & & 6+ & 62 (5.22) & 266 (23.15) & \\ \cline{3-5}  & \multicolumn{2}{c}{CCI score (mean, SD)} & 2.09 (1.80) & 3.85 (2.50) & \textless{}0.001 \\ \hline \multicolumn{5}{c}{One year before variables} \\ \hline X4 & Previous CABG surgery & 7 (0.59) & 13 (1.13) & 0.1549 \\ X5 & Length of ICU stay (Days) & 0.16 (1.69) & 0.94 (6.83) & \textless{}0.001 \\ X6 & Blood transfusion (Bags) & 0.12 (0.85) & 0.88 (3.82) & \textless{}0.001 \\ X7 & Mechanical ventilation (Days) & 0.12 (1.05) & 0.87 (11.25) & 0.0244 \\ \hline \multicolumn{5}{c}{Current surgical variables} \\ \hline X8 & Blood transfusion (Bags) & 0.17 (1.55) & 3.42 (15.78) & \textless{}0.001 \\ X9 & Mechanical ventilation (Days) & 0.13 (1.23) & 3.45 (24.23) & \textless{}0.001 \\ X10 & Length of ICU stay (Days) & 0.23 (2.07) & 0.65 (4.80) & 0.0063 \\ X11 & Length of Stay (Days) & 4.29 (4.74) & 9.85 (12.30) & \textless{}0.001 \\ \hline \multicolumn{5}{c}{Underlying diseases} \\ \hline X12 & Hypertension & 52 (4.38) & 73 (6.35) & 0.0338 \\ X13 & Hyperlipidemia & 850 (71.55) & 470 (40.91) & \textless{}0.001 \\ X14 & Hyperuricemia & 52 (4.38) & 30 (2.61) & 0.0204 \\ X15 & Diabetes & 499 (42) & 644 (56.05) & \textless{}0.001 \\ X16 & Liver cirrhosis & 6 (0.51) & 27 (2.35) & \textless{}0.001 \\ X17 & COPD & 108 (0.90) & 228 (19.84) & \textless{}0.001 \\ X18 & Skin bone & 128 (10.77) & 158 (13.75) & 0.0282 \\ X19 & Stroke & 105 (8.84) & 228 (19.84) & \textless{}0.001 \\ X20 & Gout & 156 (13.13) & 166 (14.45) & 0.3561 \\ X21 & Biliary stone & 27 (2.27) & 25 (2.18) & 0.8738 \\ X22 & HBV & 39 (3.28) & 21 (1.83) & 0.0262 \\ X23 & HCV & 19 (1.6) & 24 (2.09) & 0.3788 \\ \hline \multicolumn{5}{c}{Heart-related characteristics} \\ \hline X24 & AF & 32 (2.69) & 105 (9.14) & \textless{}0.001 \\ X25 & CHF & 175 (14.73) & 537 (46.74) & \textless{}0.001 \\ X26 & PVD & 49 (4.12) & 102 (8.88) & \textless{}0.001 \\ X27 & ACS & 487 (40.99) & 654 (56.92) & \textless{}0.001 \\ X28 & Malignant dysrhythmia & 21 (1.77) & 80 (6.96) & \textless{}0.001 \\ X29 & Cardiogenic shock & 11 (0.93) & 87 (7.57) & \textless{}0.001 \\ \hline \multicolumn{5}{c}{Renal-Related characteristics} \\ \hline X30 & KD & 79 (6.65) & 389 (33.86) & \textless{}0.001 \\ X31 & CRF & 35 (2.95) & 296 (25.76) & \textless{}0.001 \\ X32 & AKF & 12 (1.01) & 112 (9.75) & \textless{}0.001 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Baseline characteristics of patients who underwent 3-vessel PCI. Some patient characteristics were significantly different between the survival and death groups.