Clinical Investigation
Percutaneous Coronary Intervention to Treat Chronic Total Occlusion: Predictors of Technical Success and One-Year Clinical Outcome
Mojtaba Salarifar, MD Mohammad-Reza Mousavi, MD Sepideh Saroukhani, MD Ebrahim Nematipour, MD Seyed Ebrahim Kassaian, MD Mohammad Alidoosti, MD Hamid-Reza Poorhosseini, MD Ali-Mohammad Haji-Zeinali, MD Younes Nozari, MD Kianoush Hosseini, MD Arash Jalali, PhD
We investigated the overall success rate of percutaneous coronary intervention (PCI) as a treatment for coronary chronic total occlusion and sought to determine the predictive factors of technical success and of one-year major adverse cardiac events (MACE). These factors have not been conclusively defined. Using data from our single-center PCI registry, we enrolled 269 consecutive patients (mean age, 56.13 ± 10.72 yr; 66.2% men) who underwent first-time PCI for chronic total occlusion (duration, ≥3 mo) from March 2006 through September 2010. We divided them into 2 groups: procedural success and procedural failure. We compared occurrences of inhospital sequelae and one-year MACE between the groups, using multivariate models to determine predictors of technical failure and one-year clinical outcome. Successful revascularization was achieved in 221 patients (82.2%). One-year MACE occurred in 13 patients (4.8%), with a predominance of target-vessel revascularization (3.7%). The prevalence of MACE was significantly lower in the procedural-success group (1.8% vs 18.8%; P 75° were considered to have moderate-tosevere tortuosity. Moderate-to-severe calcification was defined as readily apparent densities within the vascular wall at the site of the stenosis. The angiographic structure of the occlusion was defined as “tapered-stump” if the artery ended in a funnel shape. Intracoronary microchannels at the site of the occlusion were considTexas Heart Institute Journal
ered to be bridging collateral vessels that established the chronicity of the occlusion.16 Contralateral injection, performed in some cases, was defined as simultaneous dye injection to show the distal portion of the vessel after the occlusion site (filled via collateral vessels) and to estimate the length of the occlusion.17 Postprocedural MI was defined as an elevation of creatine kinase-MB mass to at least 3 times the upper limit of normal after the procedure (our laboratory’s normal limit of creatine kinase-MB is 6.73 ng/mL for men and 3.77 ng/mL for women). In patients who had a postprocedural MI that was related to the target lesion, the development of new Q waves in the electrocardiographic leads indicated a Q-wave MI.18 The study endpoint was the occurrence of MACE during the follow-up period: cardiac death, nonfatal MI, target-lesion revascularization, or target-vessel revascularization (TVR). Target-lesion revascularization was defined either as repeat percutaneous or surgical revascularization for a lesion anywhere within the stent or within 5-mm borders proximal or distal to the stent. Target-vessel revascularization was defined as PCI or CABG for chest pain or positive noninvasive-test results (exercise stress test, stress echocardiogram, or radionuclide study showing reversible defects) for ischemia consequent to a lesion in the same epicardial vessel. Evaluation Protocol
One independent reviewer retrospectively evaluated all angiograms and angioplasty films, and all reported data arose from that reviewer’s decisions. A different independent reviewer reviewed the images from a randomly selected 15% of the patients. The level of agreement between the reviewers was 93.5%. In the evaluation of bridging collateral vessels and moderate-to-severe calcification, interobserver variability was 6.5% and 3.2%, respectively. Interventional Procedure
Before PCI, all patients were given aspirin orally (325 mg), a clopidogrel loading dose (600 mg, at least 2 hr before), and weight-adjusted unfractionated heparin (80–100 U/kg) intravenously. The technical approach and procedural devices were chosen by the interventional cardiologists. The antegrade approach was routinely used, and, depending on procedural progress, different strategies and the use of stiffer wires were considered. Contralateral injection was performed in some patients. In the successful-procedure group, clopidogrel (75 mg/d) was prescribed for 12 months to patients who received a drug-eluting stent (DES) and for at least 3 months to patients who received a bare-metal stent (BMS). The patients with a DES were discharged from the hospital with instructions to take 325 mg/d of aspirin for at least 3 months; the patients with a BMS were instructed to take that dose of aspirin for at least 1 Percutaneous Coronary Intervention for Chronic Occlusion
41
month. Thereafter, 80 mg/d of aspirin was prescribed for an indefinite period after PCI. Statistical Analysis
Results are presented as mean ± SD for numerical variables and as number and percentage for categorical variables. The Student t or Mann-Whitney U test was used to compare continuous variables, and the c2 or Fisher exact test was used to compare categorical variables. For one-year MACE-free outcome, survival curves were estimated by means of the Kaplan-Meier method (the standard estimator of the survival function) and were compared between the 2 groups by means of the logrank test. Variables with a univariate P value 2 mg/dL. Data are presented as mean ± SD or as number and percentage. P ≤0.05 was considered statistically significant.
42
Percutaneous Coronary Intervention for Chronic Occlusion
Volume 41, Number 1, 2014
TABLE II. Angiographic and Procedural Characteristics
Variable
Total (N=269)
Procedural Success Procedural Failure (n=221) (n=48)
P Value
Target vessel LAD Right coronary artery LCx
— 170 (63.2) 72 (26.8) 27 (10)
— 141 (63.8) 58 (26.2) 22 (10)
— 29 (60.4) 14 (29.2) 5 (10.4)
0.902 — — —
Lesion location Ostial Proximal Mid portion Distal
— 12 (4.5) 82 (30.5) 165 (61.3) 10 (3.7)
— 7 (3.2) 70 (31.7) 137 (62) 7 (3.2)
— 5 (10.4) 12 (25) 28 (58.3) 3 (6.3)
0.089 — — — —
30.82 ± 13.64
31.51 ± 13.88
27.5 ± 11.96
0.05
159 (59.1)
123 (55.7)
10 (3.7)
10 (4.5)
0
0.213
174 (64.7)
153 (69.2)
21 (43.8)
0.001
9 (3.3)
7 (3.2)
2 (4.2)
0.664
9 (18.8)
0.05
Lesion length Side branch Bridging collateral vessels Tapered stump Vessel tortuosity Moderate-to-severe calcification TIMI flow grade before PCI 0 1
29 (10.8)
20 (9)
36 (75)
0.013
— 161 (59.9) 108 (40.1)
— 123 (55.7) 98 (44.3)
— 38 (79.2) 10 (20.8)
0.003 — —
24 (8.9)
14 (6.3)
10 (20.8)
0.004
Type of PCI Bare-metal stent Drug-eluting stent
— 45 (16.7) 178 (66.2)
— 45 (20.4) 176 (79.6)
— 0 2 (4.2)
Guiding catheter type Extra support Judkins
— 92 (34.2) 177 (65.8)
— 76 (34.4) 145 (65.6)
— 16 (33.3) 32 (66.7)
0.889 — —
Guiding catheter size 6F 7F
— 181 (67.3) 88 (32.7)
— 149 (67.4) 72 (32.6)
— 32 (66.7) 16 (33.3)
0.92 — —
Guidewires Hydrophilic Nonhydrophilic
— 112 (41.6) 157 (58.4)
— 90 (40.7) 131 (59.3)
— 0.515 22 (45.8) — 26 (54.2) —
Contralateral injection
Percutaneous Coronary Intervention to Treat Chronic Total Occlusion: Predictors of Technical Success and One-Year Clinical Outcome
Mojtaba Salarifar, MD Mohammad-Reza Mousavi, MD Sepideh Saroukhani, MD Ebrahim Nematipour, MD Seyed Ebrahim Kassaian, MD Mohammad Alidoosti, MD Hamid-Reza Poorhosseini, MD Ali-Mohammad Haji-Zeinali, MD Younes Nozari, MD Kianoush Hosseini, MD Arash Jalali, PhD
We investigated the overall success rate of percutaneous coronary intervention (PCI) as a treatment for coronary chronic total occlusion and sought to determine the predictive factors of technical success and of one-year major adverse cardiac events (MACE). These factors have not been conclusively defined. Using data from our single-center PCI registry, we enrolled 269 consecutive patients (mean age, 56.13 ± 10.72 yr; 66.2% men) who underwent first-time PCI for chronic total occlusion (duration, ≥3 mo) from March 2006 through September 2010. We divided them into 2 groups: procedural success and procedural failure. We compared occurrences of inhospital sequelae and one-year MACE between the groups, using multivariate models to determine predictors of technical failure and one-year clinical outcome. Successful revascularization was achieved in 221 patients (82.2%). One-year MACE occurred in 13 patients (4.8%), with a predominance of target-vessel revascularization (3.7%). The prevalence of MACE was significantly lower in the procedural-success group (1.8% vs 18.8%; P 75° were considered to have moderate-tosevere tortuosity. Moderate-to-severe calcification was defined as readily apparent densities within the vascular wall at the site of the stenosis. The angiographic structure of the occlusion was defined as “tapered-stump” if the artery ended in a funnel shape. Intracoronary microchannels at the site of the occlusion were considTexas Heart Institute Journal
ered to be bridging collateral vessels that established the chronicity of the occlusion.16 Contralateral injection, performed in some cases, was defined as simultaneous dye injection to show the distal portion of the vessel after the occlusion site (filled via collateral vessels) and to estimate the length of the occlusion.17 Postprocedural MI was defined as an elevation of creatine kinase-MB mass to at least 3 times the upper limit of normal after the procedure (our laboratory’s normal limit of creatine kinase-MB is 6.73 ng/mL for men and 3.77 ng/mL for women). In patients who had a postprocedural MI that was related to the target lesion, the development of new Q waves in the electrocardiographic leads indicated a Q-wave MI.18 The study endpoint was the occurrence of MACE during the follow-up period: cardiac death, nonfatal MI, target-lesion revascularization, or target-vessel revascularization (TVR). Target-lesion revascularization was defined either as repeat percutaneous or surgical revascularization for a lesion anywhere within the stent or within 5-mm borders proximal or distal to the stent. Target-vessel revascularization was defined as PCI or CABG for chest pain or positive noninvasive-test results (exercise stress test, stress echocardiogram, or radionuclide study showing reversible defects) for ischemia consequent to a lesion in the same epicardial vessel. Evaluation Protocol
One independent reviewer retrospectively evaluated all angiograms and angioplasty films, and all reported data arose from that reviewer’s decisions. A different independent reviewer reviewed the images from a randomly selected 15% of the patients. The level of agreement between the reviewers was 93.5%. In the evaluation of bridging collateral vessels and moderate-to-severe calcification, interobserver variability was 6.5% and 3.2%, respectively. Interventional Procedure
Before PCI, all patients were given aspirin orally (325 mg), a clopidogrel loading dose (600 mg, at least 2 hr before), and weight-adjusted unfractionated heparin (80–100 U/kg) intravenously. The technical approach and procedural devices were chosen by the interventional cardiologists. The antegrade approach was routinely used, and, depending on procedural progress, different strategies and the use of stiffer wires were considered. Contralateral injection was performed in some patients. In the successful-procedure group, clopidogrel (75 mg/d) was prescribed for 12 months to patients who received a drug-eluting stent (DES) and for at least 3 months to patients who received a bare-metal stent (BMS). The patients with a DES were discharged from the hospital with instructions to take 325 mg/d of aspirin for at least 3 months; the patients with a BMS were instructed to take that dose of aspirin for at least 1 Percutaneous Coronary Intervention for Chronic Occlusion
41
month. Thereafter, 80 mg/d of aspirin was prescribed for an indefinite period after PCI. Statistical Analysis
Results are presented as mean ± SD for numerical variables and as number and percentage for categorical variables. The Student t or Mann-Whitney U test was used to compare continuous variables, and the c2 or Fisher exact test was used to compare categorical variables. For one-year MACE-free outcome, survival curves were estimated by means of the Kaplan-Meier method (the standard estimator of the survival function) and were compared between the 2 groups by means of the logrank test. Variables with a univariate P value 2 mg/dL. Data are presented as mean ± SD or as number and percentage. P ≤0.05 was considered statistically significant.
42
Percutaneous Coronary Intervention for Chronic Occlusion
Volume 41, Number 1, 2014
TABLE II. Angiographic and Procedural Characteristics
Variable
Total (N=269)
Procedural Success Procedural Failure (n=221) (n=48)
P Value
Target vessel LAD Right coronary artery LCx
— 170 (63.2) 72 (26.8) 27 (10)
— 141 (63.8) 58 (26.2) 22 (10)
— 29 (60.4) 14 (29.2) 5 (10.4)
0.902 — — —
Lesion location Ostial Proximal Mid portion Distal
— 12 (4.5) 82 (30.5) 165 (61.3) 10 (3.7)
— 7 (3.2) 70 (31.7) 137 (62) 7 (3.2)
— 5 (10.4) 12 (25) 28 (58.3) 3 (6.3)
0.089 — — — —
30.82 ± 13.64
31.51 ± 13.88
27.5 ± 11.96
0.05
159 (59.1)
123 (55.7)
10 (3.7)
10 (4.5)
0
0.213
174 (64.7)
153 (69.2)
21 (43.8)
0.001
9 (3.3)
7 (3.2)
2 (4.2)
0.664
9 (18.8)
0.05
Lesion length Side branch Bridging collateral vessels Tapered stump Vessel tortuosity Moderate-to-severe calcification TIMI flow grade before PCI 0 1
29 (10.8)
20 (9)
36 (75)
0.013
— 161 (59.9) 108 (40.1)
— 123 (55.7) 98 (44.3)
— 38 (79.2) 10 (20.8)
0.003 — —
24 (8.9)
14 (6.3)
10 (20.8)
0.004
Type of PCI Bare-metal stent Drug-eluting stent
— 45 (16.7) 178 (66.2)
— 45 (20.4) 176 (79.6)
— 0 2 (4.2)
Guiding catheter type Extra support Judkins
— 92 (34.2) 177 (65.8)
— 76 (34.4) 145 (65.6)
— 16 (33.3) 32 (66.7)
0.889 — —
Guiding catheter size 6F 7F
— 181 (67.3) 88 (32.7)
— 149 (67.4) 72 (32.6)
— 32 (66.7) 16 (33.3)
0.92 — —
Guidewires Hydrophilic Nonhydrophilic
— 112 (41.6) 157 (58.4)
— 90 (40.7) 131 (59.3)
— 0.515 22 (45.8) — 26 (54.2) —
Contralateral injection
