Baseline characteristics
A total of 124 patients (96.1%) in whom CTO-PCI was successful were included in the study, including 42 (33.9%) who had confirmed PMI and 82 (66.1%) who did not have PMI. More patients who developed PMI had diabetes (54.8% vs 31.7%,P = 0.013)and dyslipidemia (54.8% vs 13.4%,P<0.001)than those who did not develop PMI. In addition,there were significant differences between the two groups in left ventricular ejection fraction (LVEF)(43.2 ± 7.2vs47.2 ± 8.0, P = 0.027), prior myocardial infarction(54.8%vs43.1%, P = 0.020), prior PCI(57.1%vs22.0%, P<0.001) and prior CABG(14.3%vs2.4%, P = 0.011)(Table 1).
Table 1
Clinical characteristics of 2 groups Number(%) M(P25,P75), mean ± SD
|
PMI group(n = 42)
|
Control group (n = 82)
|
P value
|
Age>65years
|
25(59.5)
|
47(57.3)
|
0.814
|
Female gender
|
16(38.1)
|
28(43.1)
|
0.664
|
BMI(Kg/m2)
|
25.3 ± 3.6
|
24.5 ± 3.1
|
0.322
|
BMI>28Kg/m2
|
9(21.4)
|
14(17.1)
|
0.555
|
Smoke,current
|
21(50.0)
|
45(54.9)
|
0.606
|
Hypertension
|
25(59.5)
|
42(51.2)
|
0.380
|
Diabetes
|
23(54.8)
|
26(31.7)
|
0.013
|
Hyperlipidaemia
|
23(54.8)
|
11(13.4)
|
<0.001
|
Creatinine(µmol/l)
|
78.6 ± 39.2
|
77.6 ± 23.4
|
0.744
|
CRP rise
|
18(42.9)
|
27(32.9)
|
0.276
|
LVEF %
|
43.2 ± 7.2
|
47.2 ± 8.0
|
0.027
|
Anemia
|
13(31.0)
|
17(20.7)
|
0.208
|
Prior myocardial infarction
|
23(54.8)
|
28(34.1)
|
0.020
|
Prior stroke
|
18(42.9)
|
34(41.5)
|
0.882
|
Prior PCI
|
24(57.1)
|
18(22.0)
|
<0.001
|
Prior CABG
|
6(14.3)
|
2(2.4%)
|
0.011
|
Data presented as mean ± standard deviation or number (%) |
Bold values highlight the p values under statistical significance (< 0.05) |
PCI percutaneous coronary intervention, CABG coronary artery bypass graft, PMI periprocedural myocardial injury, LVEF left ventricular ejection fraction, BMI body mass index |
Angiographic And Procedural Characteristics
In table 2 and table 3, there was no significant difference in CTO target vessel, lesion length, the number of stents and the volume of contrast. However, patients with PMI had more calcified lesions (52.4%vs24.4%, P = 0.002) and were more likely to have multivessel artery disease (71.4%vs35.4%, P<0.001). Patients in the PMI group had higher J-CTO scores (3.3 ± 1.0vs1.9 ± 0.5, P<0.001) and were more likely to have a guidewire lesion-passing duration exceeding 30 min (64.3%vs37.8%, P = 0.005), require the use of retrograde approach (38.1%vs7.3%, P<0.001) and have procedural complications (19.0%vs2.4%, P = 0.003).
Table 2 Baseline angiographic characteristics
Number(%) M(P25,P75),mean±SD
|
PMI group(n=42)
|
Control group (n=82)
|
P value
|
Multivessel diseasea
|
30(71.4)
|
29(35.4)
|
p<0.001
|
CTO target vessel
|
|
|
|
LAD
|
16(38.1)
|
25(30.5)
|
0.394
|
LCX
|
8(19.0)
|
15(18.3)
|
0.821
|
RCA
|
18(42.9)
|
42(52.2)
|
0.378
|
CTO length>15mm
|
33(78.6)
|
61(74.4)
|
0.607
|
Calcification
|
22(52.4)
|
20(24.4)
|
0.002
|
J-CTO score
|
3.3±1.0
|
1.9±0.5
|
P<0.001
|
0
|
0(0)
|
8(9.8)
|
0.050
|
1
|
9(21.4)
|
32(39.0)
|
0.096
|
2
|
15(35.7)
|
27(32.9)
|
0.842
|
≥3
|
18(42.9)
|
15(18.3)
|
0.050
|
Rentrop grade≥2
|
29(69.0)
|
49(59.8)
|
0.311
|
Data presented as mean±standard deviation or number (%)
Bold values highlight the p values under statistical significance (<0.05)
CTO chronic total occlusion, J-CTO score Japan CTO score, LAD left anterior descending artery, LCX, left circumflex artery RCA, right coronary artery
a Defined as>50% stenosis in 2 or more major coronary arteries
Table 3 Procedural characteristics and complications.
Number(%) M(P25,P75),mean±SD
|
PMI group(n=42)
|
Control group (n=82)
|
P value
|
Access site
|
|
|
|
Radial
|
19(38.1)
|
75(91.5)
|
<0.001
|
Femoral
|
0
|
1(1.2)
|
|
Radial+femoral
|
23(61.9)
|
6(7.3)
|
<0.001
|
wire-crossing time >30min
|
27(64.3)
|
31(37.8)
|
0.005
|
Retrograde approach
|
16(38.1)
|
6(7.3)
|
<0.001
|
Drug-eluting stent
|
13(31.5)
|
18(22.0)
|
0.273
|
Number of stents
|
2.00±1.2
|
1.74±0.8
|
0.828
|
Procedure time,min
|
91.1±25.4
|
69.4±25.4
|
0.005
|
Contrast volume,mL
|
184.3±91.6
|
158.1±53.5
|
0.230
|
Procedure complications
|
|
|
|
Coronary artery perforation
|
3(7.1)
|
1(1.2)
|
0.112
|
Coronary artery dissection/haematoma
|
5(11.9)
|
1(1.2)
|
0.017
|
Overall
|
8(19.0)
|
2(2.4)
|
0.003
|
Data presented as mean±standard deviation or number (%)
Bold values highlight the p values under statistical significance (<0.05)
Determinants Of Pmi
In the univariate regression analysis, prior myocardial infarction (odd ratio[OR],2.812;confidence interval[CI], 1.300-6.084;P = 0.009), previous PCI (OR, 2.688;CI, 1.251–5.773<P = 0.011), multivessel artery disease (OR, 5.150<CI, 2.261–11.735<P<0.001), presence of calcification (OR, 3.753<CI, 1.704–8.264<P<0.001), J-CTO score ≥ 3 (OR, 0.337<CI, 0.171–0.663<P = 0.002), retrograde access (OR, 10.464<CI, 3.737–29.297<P<0.001), and presence of procedural complications (OR, 9.412<CI, 1.889–46.645<P = 0.006) were associated with PMI development(Table 4). In the multivariate analysis, multivessel artery disease (OR, 4.347<CI, 1.601–11.809<P = 0.004), retrograde approach (OR, 4.036<CI, 1.162–14.020<P = 0.028), and the presence of procedural complications (OR, 16.480<CI, 2.515-107.987<P = 0.003) were predictors of PMI(Table 5).
Table 4
Predictors of PMI (univariate)
|
P
|
or
|
95%CI
|
Age>65years
|
0.585
|
1.236
|
0.577–2.650
|
Hyperlipidaemia
|
0.100
|
1.882
|
0.887–3.996
|
Diabetes
|
0.452
|
1.333
|
0.631–2.820
|
LVEF<40%
|
0.114
|
2.002
|
0.846–4.737
|
Prior myocardial infarction
|
0.009
|
2.812
|
1.300-6.084
|
Prior stroke
|
0.688
|
1.166
|
0.551–2.468
|
Prior PCI
|
0.011
|
2.688
|
1.251–5.773
|
Multivessel artery diseasea
|
P<0.001
|
5.150
|
2.261–11.735
|
CTO length>15mm
|
0.415
|
1.463
|
0.585–3.657
|
Calcification
|
P<0.001
|
3.753
|
1.704–8.264
|
Retrograde approach
|
P<0.001
|
10.464
|
3.737–29.297
|
Procedure complications
|
0.006
|
9.412
|
1.899–46.645
|
Logistic binary regression |
OR odd ratio, CI confidence interval, LVEF left ventricular ejection fraction, PCI percutaneous coronary intervention |
a Defined as>50% stenosis in 2 or more major coronary arteries |
Table 5
Predictors of PMI (multivariate)
|
P
|
or
|
95%CI
|
Prior myocardial infarction
|
0.247
|
3.674
|
0.406–33.282
|
Prior PCI
|
0.743
|
0.695
|
0.079–6.117
|
Multivessel artery diseasea
|
0.004
|
4.347
|
1.601–11.809
|
Calcification
|
0.298
|
1.782
|
0.600-5.291
|
Retrograde approach
|
0.028
|
4.036
|
1.162–14.020
|
Procedure complications
|
0.003
|
16.480
|
2.515-107.987
|
a Defined as>50% stenosis in 2 or more major coronary arteries |
OR odd ratio, CI confidence interval, LVEF left ventricular ejection fraction, PCI percutaneous coronary intervention |
Clinical Outcomes
From Table 6, ten patients (8.1%) developed MACE during hospitalization, while there was one (0.8%) cardiogenic death. More patients in the PMI group developed MACE (14.3%vs2.4%, P = 0.011)and required target vessel revascularization (11.9%vs2.4%, P<0.001).
Table 6 Clinical events after procedural
Number(%) M(P25,P75),mean±SD
|
PMI group(n=42)
|
Control group (n=82)
|
P value
|
Overall
|
7(16.7)
|
3(3.7)
|
0.011
|
Cardiac death
|
1(2.3)
|
0(0)
|
|
target vessel revascularization
|
5(11.9)
|
2(2.4)
|
<0.001
|
Acute heart failure
|
1(2.3)
|
1(1.2)
|
|
Data presented as mean±standard deviation or number (%)
Bold values highlight the p values under statistical significance (<0.05)