Abstract
Background
Limited data exist on the treatment of chronic total occlusions (CTO) due to in-stent restenosis (ISR).
Methods
We reviewed the procedural techniques and outcomes of 21 consecutive interventions in CTOs due to ISR.
Results
Mean age was 60±8 years, and all patients were men. The target lesion was located in the right coronary artery in 38%, left anterior descending or diagonal in 48%, or circumflex/obtuse marginal in 14%. One CTO lesion was treated in each patient. Two patients (10%) had prior unsuccessful attempt for CTO intervention and 14% had prior coronary artery bypass graft surgery. The average CTO age was 6.3±4.6 years. The overall ISR CTO procedural success rate was 71%. Procedural failure was due to inability to cross the CTO lesion in all unsuccessful cases. Failure to cross in CTOs located in the left anterior descending artery was due to the presence of a large side branch proximal to the CTO, whereas in the right coronary artery it was due to tortuosity. Retrograde interventions were attempted in four patients and were successful in one.
Conclusion
Success rates for ISR CTO interventions remain relatively low due to failure to cross the lesion. Several factors, such as long occlusion time, tortuosity, and presence of a large side branch proximal to the CTO may be associated with ISR CTO crossing failure.
1
Introduction
Total occlusion of native coronary artery lesions is relatively rare after stenting and chronic total occlusions (CTOs) due to in-stent restenosis (ISR) is an understudied subgroup of CTO interventions . Although the previously deployed stent can serve as marker of the vessel course, reported success rates have often been low . We examined our recent experience with interventions in CTO due to ISR to determine success rates, causes of procedural failure and potential techniques that could improve procedural outcomes.
2
Methods
2.1
Study population
We identified 131 consecutive patients who underwent percutaneous coronary intervention (PCI) for a CTO at our institution between March 2008 and March 2010. Of those patients, 21 (16%) patients had PCI of a CTO that was due to ISR and were included in the present study. Their medical records and coronary angiograms were reviewed to determine the clinical and angiographic characteristics, techniques utilized, and success rates of those interventions.
2.2
Definitions
In-stent restenosis CTO was defined as an obstruction of a previously stented coronary artery with TIMI flow grade 0 and an estimated duration of at least 3 months .
Procedural success was defined as achievement of residual post-PCI stenosis <30% in the target lesion, associated with Thrombolysis in Myocardial Infarction (TIMI) 2–3 blood flow, without the occurrence of death, myocardial infarction (MI), or repeat lesion revascularization during the index hospitalization . All cases were done via the femoral approach using 6–8F guides. The choice of procedural strategies, equipment utilization and anticoagulation and antiplatelet regimens were at the discretion of the interventional cardiologist performing the procedure.
2.3
Statistical analysis
Continuous parameters were reported as mean±S.D and discrete parameters were reported as percentages. All analyses were performed using JMP 8 (SAS Institute, Cary, NC, USA). The study was approved by our institutional review board.
2
Methods
2.1
Study population
We identified 131 consecutive patients who underwent percutaneous coronary intervention (PCI) for a CTO at our institution between March 2008 and March 2010. Of those patients, 21 (16%) patients had PCI of a CTO that was due to ISR and were included in the present study. Their medical records and coronary angiograms were reviewed to determine the clinical and angiographic characteristics, techniques utilized, and success rates of those interventions.
2.2
Definitions
In-stent restenosis CTO was defined as an obstruction of a previously stented coronary artery with TIMI flow grade 0 and an estimated duration of at least 3 months .
Procedural success was defined as achievement of residual post-PCI stenosis <30% in the target lesion, associated with Thrombolysis in Myocardial Infarction (TIMI) 2–3 blood flow, without the occurrence of death, myocardial infarction (MI), or repeat lesion revascularization during the index hospitalization . All cases were done via the femoral approach using 6–8F guides. The choice of procedural strategies, equipment utilization and anticoagulation and antiplatelet regimens were at the discretion of the interventional cardiologist performing the procedure.
2.3
Statistical analysis
Continuous parameters were reported as mean±S.D and discrete parameters were reported as percentages. All analyses were performed using JMP 8 (SAS Institute, Cary, NC, USA). The study was approved by our institutional review board.
3
Results
3.1
Baseline characteristics
The baseline demographic characteristics for the study patients are shown in Table 1 . The mean interval between initial stent implantation and the PCI attempt to treat the ISR lesion was 6.3±4.6 years. The type of stent that developed occlusive ISR was known in 10 patients: it was drug-eluting (DES) in 8 patients, bare metal (BMS) in one patient and both DES and BMS in one patient. Patients presented with stable angina (67%), with a recent acute coronary syndrome that was due to a lesion unrelated to the CTO (19%) or with another indication (arrhythmia or heart failure exacerbation) (14%). All patients with a recent acute coronary syndrome had a non-CTO culprit lesion that was initially treated and subsequently returned for CTO PCI because of persistent symptoms and ischemia in the CTO artery distribution.
| Variable | All patients ( n =21) | Success ( n =15) | Failure ( n =6) | P |
|---|---|---|---|---|
| Age (years) | 60±8 | 61±8.9 | 57.5±3.8 | .40 |
| BMI (kg/m 2 ) | 32±7 | 29±3.7 | 38±11 | .01 |
| Ethnicity, n (%) | .17 | |||
| Caucasian | 15 (71%) | 12 (80%) | 3 (50%) | |
| African American | 6 (29%) | 3 (20%) | 3 (50%) | |
| Hypertension, n (%) | 19 (90%) | 14 (93%) | 5 (83%) | .48 |
| Hyperlipidemia, n (%) | 20 (95%) | 15 (100%) | 5 (83%) | .10 |
| Diabetes mellitus, n (%) | 9 (43%) | 7 (47%) | 2 (33%) | .57 |
| Past smoker, n (%) | 19 (90%) | 14 (93%) | 5 (83%) | .48 |
| Current smoker, n (%) | 10 (48%) | 8 (53%) | 2 (33%) | .40 |
| Never smoker | 2 (10%) | 1 (7%) | 1 (17%) | .48 |
| Prior MI, n (%) | 13 (62%) | 9 (60%) | 4 (67%) | .77 |
| Prior CABG, n (%) | 3 (14%) | 3 (20%) | 0 (0%) | .23 |
| Prior CHF, n (%) | 10 (48%) | 7 (47%) | 3 (50%) | .89 |
| Indication for PCI, n (%) | .26 | |||
| Stable Angina | 14 (67%) | 9 (60%) | 5 (83%) | |
| Recent ACS | 4 (19%) | 3 (20%) | 1 (17%) | |
| Other | 3 (14%) | 3 (14%) | 0 (0%) | |
| Time since initial PCI (years) | 6.3±4.6 | 5±4.4 | 9.5±3.6 | .04 |
| Lesion length (mm) | 38±18 | 38±17.5 | 38±22 | .94 |
| Degree of angulation | 65±37 | 73.3±27 | 45±52 | .11 |
| Calcification, n (%) | .95 | |||
| No calcification | 15 (71%) | 11 (73%) | 4 (67%) | |
| Moderate calcification | 3 (14%) | 2 (13%) | 1 (17%) | |
| Severe calcification | 3 (14%) | 2 (13%) | 1 (17%) | |
| Duration of procedure (h) | 1.97±0.7 | 2±0.6 | 1.8±0.8 | .51 |
| Contrast volume (ml) | 306±72 | 307±67 | 302±89 | .87 |
| Fluoroscopy time (min) | 37±17 | 32.5±18 | 47±4.7 | .06 |
| Last ACT (s) | 246±57 | 251±62.5 | 227±24 | .47 |
| Target vessel | .73 | |||
| Left anterior descending artery | 9 (43%) | 6 (40%) | 3 (50%) | |
| Right coronary artery | 8 (38%) | 5 (33%) | 3 (50%) | |
| Circumflex | 2 (10%) | 2 (13%) | 0 (0%) | |
| Obtuse marginal | 1 (4.5%) | 1 (7%) | 0 (0%) | |
| Diagonal | 1 (4.5%) | 1 (7%) | 0 (0%) | |
| Primary approach, n (%) | .48 | |||
| Antegrade | 19 (90%) | 14 (93%) | 5 (83%) | |
| Retrograde | 2 (10%) | 1 (7%) | 1 (17%) | |
| Dual injection used | 5 (24%) | 4 (27%) | 1 (17%) | .62 |
| Total number of wires | 5.4±2.7 | 4.9±2.16 | 6.8±3.7 | .14 |
| No. of stents used | 3.2±1.2 | NA | ||
| Total stent length (mm) | 65.5±24 | NA |
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