Percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) has been traditionally associated with lower success rates in patients with previous coronary artery bypass graft surgery (CABG). We sought to examine the success and complication rates of CTO PCI using the “hybrid” crossing algorithm among patients with a history of previous CABG. The procedural outcomes of 496 consecutive CTO PCIs performed at 5 high-volume PCI centers in the United States from January 2012 to August 2013 were assessed. The outcomes of patients with previous CABG were compared with those of patients without previous CABG. Compared with patients without previous CABG (n = 320), patients with previous CABG (n = 176, 35%) were older, had more coronary artery disease risk factors, and had less favorable baseline angiographic CTO characteristics. Technical and procedural success was slightly lower among patients with previous CABG (88.1% vs 93.4%, p = 0.044 and 87.5 vs 92.5%, p = 0.07, respectively). Patients with previous CABG more commonly underwent CTO PCI using the retrograde approach (39% vs 24%, respectively, p <0.001) and received higher air kerma radiation exposure (4.8 [interquartile range 3.0 to 6.4] vs 3.1 [1.9 to 5.3] Gray, p <0.001) and fluoroscopy time (59 [38 to 77] vs 34 [21 to 55] minutes, p <0.001). Major procedural complications were similar in the 2 groups: 2 of 176 (1.1%) patients with previous CABG versus 7 of 320 (2.1%) patients without previous CABG (p = 0.40). In conclusion, with application of the “hybrid” approach to CTO PCI, success was slightly lower, and complication rates were similar between patients with and without previous CABG.
Coronary chronic total occlusion (CTO) percutaneous coronary intervention (PCI) is often indicated in patients with previous coronary artery bypass graft surgery (CABG) but has been associated with lower procedural success rates, likely due to higher lesion complexity, coexisting diffuse, multivessel disease, disrupted anatomy at the anastomosis, and severe coronary calcification. The recent introduction of the “hybrid” approach to CTO PCI is associated with higher CTO PCI success rates, especially among more complex CTOs, such as those encountered in patients with previous CABG. The goal of the present study was to compare contemporary outcomes with the “hybrid” approach to CTO PCI between patients with and without previous CABG.
Methods
We examined the procedural techniques and outcomes of 496 consecutive CTO PCIs performed using the “hybrid” approach from January 2011 to August 2013 at 5 US centers: Appleton Cardiology, Appleton, Wisconsin; Piedmont Heart Institute, Atlanta, Georgia; St. Joseph Medical Center, Bellingham, Washington; St. Luke’s Health System’s Mid-America Heart Institute, Kansas City, Missouri; and VA North Texas Healthcare System, Dallas, Texas (Prospective Global Registry for the Study of Chronic Total Occlusion Intervention [PROGRESS CTO] NCT02061436). All procedures were performed by operators with significant expertise in CTO PCI using the “hybrid” approach. The first step in the “hybrid” algorithm is the performance of dual injection that is used to assess 4 key angiographic CTO characteristics: (1) proximal cap ambiguity; (2) quality of the vessel distal to the occlusion; (3) lesion length; and (4) presence of adequate collateral. Initial antegrade wire escalation is favored for lesions <20 mm, whereas antegrade dissection and re-entry is favored for lesions >20 mm. An initial retrograde (primary retrograde) approach is favored for lesions with ambiguous proximal cap, diffuse distal disease, and bifurcation at the distal cap, when appropriate collateral vessels are present. Early change of crossing strategy is recommended if the initially selected crossing strategy is unsuccessful or if no significant progress is achieved within a short period. The study was approved by the institutional review board of each site.
Coronary CTOs were defined as coronary lesions with Thrombolysis In Myocardial Infarction (TIMI) grade 0 flow of at least 3-month duration. Estimation of the occlusion duration was based on first onset of anginal symptoms, history of myocardial infarction in the target vessel territory, or comparison with a previous angiogram. Technical success of CTO PCI was defined as successful CTO revascularization with achievement of <30% residual diameter stenosis within the treated segment and restoration of TIMI grade 3 antegrade flow. Procedural success was defined as achievement of technical success with no in-hospital major adverse cardiac events (MACE). In-hospital MACE included any of the following adverse events before hospital discharge: death from any cause, Q-wave myocardial infarction, recurrent symptoms requiring urgent repeat target vessel revascularization with PCI or coronary bypass graft surgery, tamponade requiring either pericardiocentesis or surgery, and stroke. The J-CTO score was calculated as described by Morino et al.
Continuous data are summarized as mean ± SD (normally distributed data) or median and interquartile range (non-normally distributed data) and compared using t test or Wilcoxon rank-sum test, as appropriate. Categorical data are presented as frequencies or percentages and compared using chi-square or Fisher’s exact test, as appropriate. Logistic regression analysis was performed to assess the association between previous CABG and technical success. A p value of <0.05 was considered statistically significant. Statistical analyses were performed using JMP version 9.0 (SAS Institute, Cary, North Carolina).
Results
Of the 496 consecutive patients who underwent CTO PCI during the study period, 176 had a history of previous CABG (35%). The clinical and angiographic characteristics of the study patients are listed in Table 1 . Compared with patients without previous CABG, patients with previous CABG were older, less likely to be current smokers and more likely to have diabetes and previous myocardial infarction. Patients with previous CABG tended to undergo left circumflex artery CTO PCI more often (18% vs 10%, respectively, p = 0.07) and left anterior descending artery (LAD) CTO PCI less often (13% vs 24%, respectively, p = 0.07) compared with patients without previous CABG. Only 1 patient underwent PCI of a saphenous vein graft (SVG) CTO. Patients with previous CABG had more complex CTO target lesions (longer, more tortuous, and calcified, with significantly higher mean J-CTO score: 3.12 ± 1.03 vs 2.41 ± 1.21, respectively, p <0.001, Table 2 ).
| Variable | Overall (n = 496) | Previous Coronary Bypass | p | |
|---|---|---|---|---|
| Yes (n = 176) | No (n = 320) | |||
| Age (years) | 65 ± 10 | 68 ± 9 | 64 ± 10 | <0.001 |
| Male | 87% | 90% | 85% | 0.08 |
| Diabetes mellitus | 42% | 49% | 38% | <0.05 |
| Dyslipidemia ∗ | 95% | 97% | 93% | 0.14 |
| Hypertension † | 90% | 93% | 89% | 0.08 |
| Previous myocardial infarction | 36% | 44% | 32% | <0.01 |
| Previous percutaneous coronary intervention | 60% | 66% | 57% | 0.12 |
| Left ventricle ejection fraction (%) | 55 (45-60) | 53 (42-55) | 55 (45-60) | 0.47 |
| Cerebrovascular disease | 9% | 10% | 9% | 0.83 |
| Baseline creatinine (mg/dl) | 1.0 (0.9-1.2) | 1.1 (0.9-1.2) | 1.0 (0.9-1.2) | 0.77 |
| Peripheral vascular disease | 18% | 22% | 15% | 0.12 |
| Current or recent (within 1 year) smoker | 40% | 34% | 43% | <0.05 |
| Patient presentation | ||||
| Acute coronary syndrome | 15% | 19% | 13% | 0.03 |
| Stable angina | 70% | 71% | 69% | |
| Symptoms unlikely to be ischemic | 7% | 2% | 9% | |
| Asymptomatic | 8% | 8% | 9% | |
| Stress test results | ||||
| Positive | 95% | 92% | 96% | 0.26 |
| Negative | 3% | 3% | 2% | |
| Indeterminate | 2% | 5% | 1% | |
∗ Based on the recommendations of the National Cholesterol Education Program Adult Treatment Panel (III).
† Defined as blood pressure of >140/90 mm Hg or >130/80 mm Hg in patients with diabetes mellitus.
| Variable | Overall | Previous Coronary Bypass | p | |
|---|---|---|---|---|
| (n = 496) | Yes (n = 176) | No (n = 320) | ||
| Target vessel | ||||
| Right | 61% | 63% | 60% | 0.07 |
| Left anterior descending artery | 20% | 13% | 24% | |
| Left circumflex artery | 12% | 18% | 10% | |
| Other | 7% | 6% | 6% | |
| Moderate or severe calcification ∗ | 57% | 74% | 47% | <0.001 |
| Moderate or severe tortuosity † | 32% | 42% | 26% | <0.001 |
| Lesion length (mm) | 30 (22-55) | 39 (28-67) | 30 (20-40) | <0.001 |
| Lesion age (months) | 22 (3-70) | 44 (6-90) | 10 (3-42) | <0.01 |
| Previous attempt to open lesion | 18% | 16% | 18% | 0.61 |
| J-CTO score | 2.67 ± 1.20 | 3.12 ± 1.03 | 2.41 ± 1.21 | <0.001 |
∗ Moderate calcification was defined as calcification involving <50% of the reference lesion diameter, whereas severe calcification was defined as calcification involving ≥50% of the reference lesion diameter.
The CTO PCI procedural outcomes are listed in Table 3 . Technical success was achieved in 155 of 176 (88.1%) patients with previous CABG and 299 of 320 (93.4%) patients without previous CABG (p = 0.044). The corresponding rates for procedural success were 154 of 176 (87.5%) and 296 of 320 (92.5%), respectively (p = 0.07). The crossing strategies utilized were different between patients with and without previous CABG, with the retrograde approach being more commonly used among patients with previous CABG (39% vs 24%, p <0.001). In patients who underwent successful retrograde revascularization septal collaterals were used less frequently among patients with previous CABG. The CTO PCIs among patients with previous CABG were more complex requiring more contrast administration (275 [200 to 400] vs 250 [180 to 360] ml, p = 0.11), longer procedure times (59 [38 to 77] vs 34 [21 to 55] minutes, p <0.001), and higher air kerma radiation exposure (4.8 [3.0 to 6.4] vs 3.1 [1.9 to 5.3] Gray, p <0.001) compared with patients without previous CABG. In logistic regression analysis, previous CABG was associated with a nearly twofold increase in the risk of technical failure (odds ratio 1.93, 95% confidence interval 1.02 to 3.66, p = 0.044).
| Variable | Overall | Previous Coronary Bypass | p | |
|---|---|---|---|---|
| (n = 496) | Yes (n = 176) | No (n = 320) | ||
| Technical success | 91.5% | 88.1% | 93.4% | 0.044 |
| Procedural success | 90.7% | 87.5% | 92.5% | 0.07 |
| Successful approach | ||||
| Antegrade wiring | 36% | 23% | 43% | <0.001 |
| Antegrade dissection and re-entry | 25% | 23% | 26% | |
| Retrograde | 29% | 39% | 24% | |
| Collaterals used in successful retrograde crossing ∗ | ||||
| Septal | 59% | 47% | 71% | 0.004 |
| Epicardial | 35% | 31% | 39% | 0.33 |
| Saphenous vein graft | 15% | 31% | 0% | <0.001 |
| Left internal mammary artery | 1% | 1% | 0% | 0.48 |
| Fluoroscopic time (min) | 41 (26-66) | 59 (38-77) | 34 (21-55) | <0.001 |
| Contrast volume (mL) | 260 (195-375) | 275 (200-400) | 250 (180-360) | 0.11 |
| Air kerma radiation exposure (Gray) | 3.8 (2.2-5.9) | 4.8 (3.0-6.4) | 3.1 (1.9-5.3) | <0.001 |
| Dose area product radiation dose (Gray-cm²) | 267 (152-413) | 356 (208-518) | 231 (134-349) | <0.01 |
| Major adverse cardiac events | 1.8% | 1.1% | 2.1% | 0.40 |
∗ More than 1 collaterals were used in some patients explaining a total of >100% in some columns.
Overall, major procedural complications occurred in 9 of 496 patients (1.8%). In the previous CABG group, major complications were reported in 2 of 176 patients (1.1%): 1 patient died due to vascular access complications and subsequent hypovolemic shock and another patient experienced a Q-wave myocardial infarction. In the no previous CABG group complications occurred in 7 of 320 patients (2.1%, p = 0.40 compared with previous CABG group). Death (due to cardiac tamponade) was reported in 1 patient, 4 patients had acute developed Q-wave myocardial infarction, 1 patient required urgent repeat target vessel PCI, and 2 patients required pericardiocentesis for tamponade ( Table 3 ).
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