Few reports are available on the safety and efficacy of percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) in older patients. In the present study, 284 patients who underwent PCI for CTOs were retrospectively evaluated by comparing the characteristics of 67 patients aged ≥75 years (the older group) and 217 patients aged <75 years (the younger group). Technical success was achieved in 77% of the patients in the older group and 79% of those in the younger group (p = 0.66). No significant differences were observed between the 2 groups in terms of the incidence of procedural complications. In the older group, a comparison between the patients with successful and failed PCI revealed significantly superior 3-year cardiac survival (97.6% vs 76.9%, p = 0.005). The 3-year cardiac survival of those with successful PCI was similar to that observed in the younger group. On multivariate analysis, successful PCI was found to be associated with a lower incidence of cardiac death in the older group (hazard ratio 0.09, 95% confidence interval 0.01 to 0.91, p = 0.042). In conclusion, this single-center, observational study suggests that PCI for CTOs can be performed with a high rate of procedural success and acceptably low mortality and morbidity in older patients, resulting in improved cardiac survival. Thus, PCI for CTO lesions should be included among the treatment strategies for older patients.
In Japan, older patients constitute the fastest growing segment of the population, and the number of older patients with complex coronary artery disease who undergo revascularization is increasing. These patients have a greater incidence of peripheral arterial disease and other co-morbidities, and their risk for developing and dying from cardiovascular disease is high. Several studies have demonstrated that percutaneous coronary intervention (PCI) for chronic total occlusions (CTOs) improves cardiac function and survival. Recent technological developments have resulted in sophisticated devices for treating CTOs, such as guidewires, and increasing clinical experience and skills have improved the procedural outcomes of PCI for CTOs. However, the risk/benefit ratio of PCI for CTOs in older patients remains poorly defined. Thus, the present study was carried out to investigate and compare the safety and efficacy of PCI for CTOs between patients aged ≥75 years and those aged <75 years.
Methods
We reviewed a consecutive series of patients in whom PCI for CTO lesions was attempted from January 2005 to December 2009 at our institution. CTO was defined as a coronary obstruction with Thrombolysis In Myocardial Infarction (TIMI) flow grade 0, with an estimated duration of ≥3 months. All included patients had ≥1 occlusion within a native vessel. The duration of the occlusion was determined by the interval from the last occurrence of acute coronary syndromes or, in patients without histories of acute coronary syndromes, from the first episode of effort angina consistent with the location of the occlusion, or on the basis of previous coronary angiographic findings. PCI for a CTO was indicated by the presence of viable myocardium in the area of the occluded vessel by echocardiography and/or left ventriculography. Patients who had undergone previous coronary artery bypass grafting (CABG) were excluded from the present study. Patients were allocated to either an “older” or a “younger” group, according to whether their age was ≥75 years or <75 years, respectively.
The hospital course was evaluated by chart review for each patient. All procedures were performed by operators highly experienced in the treatment of CTO, with the interventional strategy left to the discretion of the operators. All patients were treated with heparin to maintain an activated clotting time of >250 seconds. The postprocedural antiplatelet regimen consisted of lifelong aspirin use and clopidogrel 75 mg/day for ≥1 year. Technical success was defined as the restoration of anterograde TIMI flow grade 3 with <50% final residual stenosis. When revascularization of 2 CTOs was attempted and successful recanalization was achieved in any 1 of the 2 lesions, the procedure was categorized as a PCI success. When revascularization of the same lesion was attempted several times after failed procedures, the final result was included in the present study. Death, Q-wave myocardial infarction (MI), cardiac tamponade, emergent CABG, cerebral infarction, transfusion for major bleeding, and contrast-induced nephropathy were recorded as procedural complications. Contrast-induced nephropathy was defined as either a >25% increase of serum creatinine or an absolute increase in serum creatinine of 0.5 mg/dl.
Clinical follow-up was performed either in the outpatient clinic or by direct telephone interview. Adjunctive information was obtained from the referring physician. Major adverse cardiac events (MACEs), defined as all-cause death, Q-wave MI, or recurrent angina that resulted in target lesion revascularization (TLR), and either CABG or repeat PCI of the treated CTO, were recorded. Cardiac death included sudden death, which was defined as the sudden, unexpected death of a patient who, until then, had been considered stable.
The statistical analysis consisted of a comparison between the 2 cohorts defined according to age. Categorical variables are presented as absolute number (percentage). Continuous variables are presented as mean ± SD. Differences between groups were evaluated using chi-square or Fisher’s exact tests for categorical data and 2-tailed Student’s t tests for continuous data. Estimates of survival free from all-cause death, cardiac death, MACEs, and TLR were calculated using the Kaplan-Meier method. Comparisons between these late outcomes were made using the log-rank test. A p value <0.05 was considered statistically significant. Predictors of cardiac death in older patients were identified using multivariate Cox proportional-hazards analysis. Baseline clinical and angiographic characteristics (age, gender, current smoking, hypertension, hypercholesterolemia, diabetes mellitus, multivessel coronary disease, the left ventricular ejection fraction, previous MI in another area, left anterior descending coronary artery, and CTO length) and PCI success were included in the univariate Cox proportional-hazards analysis. However, the qualitative independent variables involving only 1-side factors were excluded from the analysis (current smoking, hypertension, diabetes mellitus, and previous MI in another area). Among the variables, 2 factors (the left ventricular ejection fraction and PCI success) with p values <0.20 in the univariate analysis were entered into the multivariate analysis using a forced-entry model. Harrell’s C-index for multivariate Cox proportional-hazards regression models was calculated. All analyses were conducted using IBM SPSS version 19 (SPSS, Inc., Chicago, Illinois) and R version 2.15.0 for Windows (R Foundation for Statistical Computing, Vienna, Austria).
Results
From January 2005 to December 2009, a total of 302 patients underwent PCI for CTO lesions. Of these, 18 patients were excluded from the present study because of previous CABG. Of the remaining 284 patients, 28 underwent PCI for 2 CTOs, for a total of 312 lesion interventions attempted. During the same period, 93 patients with CTOs underwent CABG, according to the decision of the referring physician. Most patients who underwent CABG had acute hemodynamic instability or required other cardiovascular surgical procedures, such as valve surgery or aortic aneurysm surgery, at the same time.
The baseline demographics of the study patients are listed in Table 1 . The younger group (age <75 years) included 217 patients, and the older group (age ≥75 years) included 67 patients. Compared with the younger group, the older group included more women and fewer smokers. Left ventricular ejection fractions did not differ between the 2 groups. The angiographic characteristics of the 2 groups of patients are listed in Table 2 . There were no significant differences in the distribution of the treated target vessels. Short CTO lesions (length <10 mm) tended to be more frequent in the older group.
| Variable | Age Group (yrs) | p Value | |
|---|---|---|---|
| <75 (n = 217) | ≥75 (n = 67) | ||
| Age (yrs) | 63.1 ± 8.6 | 78.5 ± 2.6 | <0.001 |
| Men | 193 (89) | 44 (66) | <0.001 |
| Current smokers | 51 (24) | 6 (9) | 0.009 |
| Hypertension ∗ | 139 (64) | 46 (69) | 0.49 |
| Hypercholesterolemia † | 142 (65) | 45 (67) | 0.80 |
| Diabetes mellitus | 88 (41) | 23 (34) | 0.36 |
| Chronic renal failure on hemodialysis | 15 (7) | 1 (2) | 0.09 |
| Multivessel coronary disease | 118 (54) | 32 (48) | 0.34 |
| Previous MI in other area | 38 (18) | 12 (18) | 0.94 |
| LVEF (%) | 59 ± 12 | 57 ± 14 | 0.27 |
∗ Blood pressure ≥140/90 mm Hg or previous pharmacologic treatment.
† Total cholesterol ≥200 mg/dl, low-density lipoprotein ≥120 mg/dl, or previous pharmacologic treatment.
| Variable | Age Group (yrs) | p Value | |
|---|---|---|---|
| <75 (n = 217) | ≥75 (n = 67) | ||
| No. of coronary lesions | 238 | 74 | — |
| Target coronary artery | |||
| Right | 111 (47) | 32 (43) | 0.69 |
| Left anterior descending | 68 (29) | 25 (34) | |
| Left circumflex | 59 (24) | 17 (23) | |
| Tortuosity | |||
| None or mild | 204 (86) | 64 (87) | 0.91 |
| Moderate | 29 (12) | 9 (12) | |
| Severe | 5 (2) | 1 (1) | |
| Calcium | |||
| None or mild | 176 (74) | 49 (66) | 0.30 |
| Moderate | 45 (19) | 16 (22) | |
| Severe | 17 (7) | 9 (12) | |
| Ostial narrowing | 12 (5) | 2 (3) | 0.31 |
| CTO length >10 mm | 180 (76) | 48 (65) | 0.07 |
| In-stent occlusion | 12 (5) | 6 (8) | 0.23 |
Procedural characteristics are listed in Table 3 . There was no significant difference between the 2 groups regarding approach site, sheath size, or the use of a bidirectional approach. Overall technical success was achieved in 79% of the younger group and 77% of the older group (p = 0.66), of whom 91% and 86%, respectively, were treated with drug-eluting stents. Although 1 older patient with severe aortic stenosis died of ventricular arrhythmia after the procedure, no significant differences between the 2 groups were observed in the overall incidence of procedural complications.
| Variable | Age Group (yrs) | p Value | |
|---|---|---|---|
| <75 (n = 217) | ≥75 (n = 67) | ||
| Procedural characteristics | |||
| No. of coronary lesions | 238 | 74 | — |
| Vascular access (anterograde ∗ ) | |||
| Radial | 109 (46) | 32 (43) | 0.87 |
| Brachial | 2 (1) | 1 (1) | |
| Femoral | 127 (53) | 41 (56) | |
| Sheath size (anterograde ∗ ) (Fr) | |||
| <6 | 3 (1) | 1 (1) | 0.99 |
| 6 | 92 (39) | 27 (37) | |
| 7 | 127 (53) | 41 (55) | |
| 8 | 16 (7) | 5 (7) | |
| Bidirectional approach | 44 (19) | 9 (12) | 0.21 |
| Amount of contrast media (ml) | 176 ± 80 | 164 ± 79 | 0.26 |
| Fluoroscopy time (min) | 18 ± 11 | 17 ± 12 | 0.66 |
| Technical success | 189 (79) | 57 (77) | 0.66 |
| Use of drug-eluting stents | 165 (91) | 49 (86) | 0.26 |
| In-hospital outcomes | |||
| Death | 0 | 1 (1.4) | 0.24 |
| Q-wave MI | 0 | 0 | — |
| Cardiac tamponade | 4 (1.7) | 0 | 0.44 |
| Emergent CABG | 1 (0.4) | 0 | 0.76 |
| Blood transfusion | 4 (1.7) | 0 | 0.34 |
| Contrast-induced nephropathy | 2 (0.8) | 0 | 0.58 |
| Cerebral infarction | 0 | 1 (1.4) | 0.24 |
∗ When a bidirectional approach was used, the access site and sheath size of the anterograde approach were used for the analysis.
Complete 3-year follow-up was conducted in 96.5% of the overall cohort (95.4% of the younger group and 100% of the older group, p = 0.07). Although not statistically significant, cardiac event–free survival was lower in the older patients than in the younger patients (93.1% vs 98.0%, p = 0.053; Figure 1 ). Survival was also compared between those with successful PCI and those with failed PCI. The Kaplan-Meier curves for freedom from cardiac death, MACEs, and TLR in the younger patients with successful or failed PCI are shown in Figure 2 , along with the curves for the older patients. In the older patients, those with successful PCI showed significantly better cardiac survival than those with failed PCI (97.6% vs 76.9%, p = 0.005; Figure 2 ). In contrast to the older patients, cardiac death–free survival in the younger patients was similar between those with successful PCI and those with failed PCI (97.6% vs 100%, p = 0.34; Figure 2 ). The cardiac survival rate of the older patients with successful PCI was similar to that of all of the younger patients, irrespective of their PCI results. With regard to MACE- and TLR-free survival, neither the younger (79.2% vs 74.7%, p = 0.23, and 84.1% vs 82.4%, p = 0.30) nor the older (64.4% vs 69.2%, p = 0.69, and 85.6% vs 91.7%, p = 0.52) patients showed significant differences between those with successful PCI and those with failed PCI ( Figure 2 ). Multivariate Cox proportional-hazards analysis revealed that successful PCI was a significant predictor of cardiac survival in the older patients (hazard ratio 0.09, 95% confidence interval 0.01 to 0.91, p = 0.042), with a C-index of 0.79 for the whole model.
