2.1 Comparison of clinical baseline data between SYNTAX low and medium-high risk group
Patients are divided into 3 groups according to SYNTAX score [11, 12]:low-risk group(SYNTAX score 0-22), medium-risk group(SYNTAX score 23-32), high-risk grouop(SYNTAX score ≥33). In view of the small number of middle-risk group and high-risk group, the two groups were combined into one group for comparison.
As shown in Table 1, compared with the low-risk group, the proportion of patients with in-hospital heart failure was higher in the SYNTAX medium-high risk group(p=0.021), while there was no statistical difference in the remaining general data. In addition,apoB/apoA1 was more likely to be defined as high-risk in SYNTAX medium-high risk group (p=0.023). Although there was no statistical difference in other serum biochemical items, the mean value of apoB/apoA1 was still higher in the middle-high risk group than the low-risk group.
Compared with the low-risk group, the proportion of patients with LM, PLAD and CIRC lesion were higher in the SYNTAX medium-high risk group(p<0.001 respectively)(Table 1).
2.2 Comparison of MACCE incidence and EQ-5D score at different time points between SYNTAX low and medium-high risk group
As shown in table 2, compared with the low-risk group, SYNTAX medium-high risk group had higher MACCE rate in hospital (p=0.049), and further significantly increased in 1 year and 3 years (p=0.011,p=0.023), while there was no statistical difference in MACCE rate in 5 years. The incidence of new or aggravated heart failure significantly increased in SYNTAX medium-high risk group after 1 year (p=0.021), but there was no statistical difference in 3 and 5 years. Moreover, the rates of cardiovascular death, new myocardial infarction, revascularization and new stroke were similar between the two groups.
2.3 Comparison of clinical baseline data between SYNTAX II low, medium and high risk group
Similarly, patients are divided into 3 groups according to SYNTAX II score [11, 12]:low-risk group(SYNTAX II score 0-21), medium-risk group(SYNTAX II score 22-28), high-risk grouop(SYNTAX II score ≥29).
Table 4 showed that except for the relevant clinical variables participating in the SYNTAX II scoring pattern, the proportion of patients with hypertension significantly increased in the medium-risk and high-risk group compared with the low-risk group(p=0.003). In addition, apoB/apoA1 was more likely to be defined as high-risk in SYNTAX II medium-risk and high-risk group(p=0.044). There was no statistical difference in the remaining general data and other serum biochemical items. Triglycerides significantly decreased in the other two groups compared with SYNTAX II low-risk group(p=0.027), which may be related to the higher proportion of myocardial infarction and/or PCI history in this group thus the long-term adherence to the low-salt and low-fat diet prescribed by their physicians.
Compared with the low-risk group, the proportion of patients with CIRC lesion were higher in the SYNTAX II medium and high-risk group(p<0.001)(Table 4).
2.4 Comparison of MACCE incidence and EQ-5D score at different time points between SYNTAX low and medium-high risk group
As shown in table 5, compared with low-risk group, SYNTAX II medium and high-risk groups had higher MACCE incidence in 5 years(p=0.032), significantly increased cardiovascular mortality in 3 and 5 years(p=0.001,p<0.001 respectively), increased proportion of new or aggravated heart failure in 3 and 5 years (p=0.015,p=0.011 respectively). The incidence of myocardial infarction, revascularization and stroke was similar among these three groups.
The baseline EQ-5D scores of SYNTAX II score groups showed a gradually decreasing trend, among which the high-risk group was the lowest(Table 6). The EQ-5D score in 1 year increased when compared with the baseline, but no statistical difference was observed among three groups, indicating that the short-term quality of life of the patients after PCI improved regardless of SYNTAX II score. Although the EQ-5D score in 5 years was higher than the baseline, it was still lower than the score in 1 year. The score of the high-risk group decreased significantly compared with the low and medium-risk group(p=0.001), which meant the patients of the SYNTAX II high-risk group had a poor long-term quality of life.
2.5 Risk factors analysis of MACCE event incidence at different time points
After adjusting for potential confounding factors, multivariate logistic regression analysis showed as follows. First, in-hospital ventricular tachycardia (OR=65.042, 95%CI: 4.147-1020.166, p=0.003) and apoB/apoA1(OR=3.429, 95%CI: 1.264~12.672, p=0.032) were independent predictors of in-hospital MACCE events. Second, SYNTAX score was an independent predictor of MACCE events in 1 year, and the risk of MACCE events in SYNTAX medium-risk group was 2.124 times as that in the low-risk group (OR=2.124, 95%CI :1.124~4.013, p=0.02), while the risk of MACCE events in SYNTAX high-risk group was 9.558 times as that in the low-risk group (OR=9.558, 95%CI :1.552~58.865, p=0.015). Third, previous history of coronary heart disease (OR=2.558, 95%CI :1.053-6.215, p=0.038), smoking (OR=1.868, 95%CI :1.026-3.402, p=0.041), apoB/apoA1(OR=2.525, 95%CI:1.332~5.385, p=0.016) and SYNTAX II score were independent predicers of MACCE events in 5 years, and the risk of MACCE events in SYNTAX II medium-risk group was 2.845 times as that in the low-risk group (OR=2.845, 95%CI :1.414-5.725, p=0.003).