Author + information
- Received May 14, 1998
- Revision received August 21, 1998
- Accepted October 6, 1998
- Published online February 1, 1999.
- Ran Kornowski, MDa,
- Roxana Mehran, MD, FACCa,
- Lowell F Satler, MD, FACCa,
- Augusto D Pichard, MD, FACCa,
- Kenneth M Kent, MD, FACCa,
- Ann Greenberg, RNa,
- Gary S Mintz, MD, FACCa,
- Mun K Hong, MD, FACCa and
- Martin B Leon, MD, FACCa,* ()
- ↵*Reprint requests and correspondence: Dr. Martin B. Leon, Director, Cardiovascular Research, Washington Cardiology Center, Suite 4B-1, 110 Irving Street, NW, Washington, D.C. 20010
To evaluate in-hospital and long-term clinical outcomes in a large consecutive series of patients undergoing percutaneous multivessel stent intervention.
High restenosis and recurrent angina rates have limited the clinical outcomes of multivessel coronary angioplasty before stents were available to improve angioplasty results.
We evaluated in-hospital and long-term clinical outcomes (death, Q-wave myocardial infarction [MI], and repeat revascularization rates at one year) in 398 consecutive patients treated with coronary stents in two (94% of patients) or three native arteries, compared to 1,941 patients undergoing stenting procedure in a single coronary artery between January 1, 1994 and August 29, 1997.
Overall procedural success was obtained in 96% of patients with two- or three-vessel stenting and in 97% of patients with single-vessel stent intervention (p = 0.36). Procedural complications were also similar (3.8% for multivessel versus 2.9% for single vessel, p = 0.14). During follow up, target lesion revascularization was 15% in multivessel and 16% in single-vessel interventions (p = 0.38), and repeat revascularization (calculated per treated patient) was also similar for both groups (20% vs. 21%, p = 0.73). There was no difference in death (1.4% vs. 0.7%, p = 0.26), and Q-wave MI (1.2% vs. 0%, p = 0.02) was lower following multivessel interventions. Overall cardiac event-free survival was similar for both groups (p = 0.52).
Unlike previous conventional angioplasty experiences, multivessel stenting has (1) similar in-hospital procedural success and major complication rates and (2) similar long-term (one year) clinical outcomes compared with single-vessel stenting. Thus, stents may be a viable therapeutic strategy in carefully selected patients with multivessel coronary disease.
Patients with multivessel coronary artery disease will often be eligible for either catheter-based interventions or coronary bypass surgery (coronary artery bypass graft [CABG]). Before the stent era, multivessel angioplasty had less favorable procedural results compared with single-vessel interventions, and long-term outcomes were compromised by the cumulative effect of restenosis (1). Consequently, the results of randomized trials comparing angiopasty with CABG differed markedly in the need for subsequent revascularization procedures and angina relief, in favor of the surgical approach (2–8). However, those randomized trials were conducted before stents were available to improve angiopasty results and reduce late restenosis (9–11). To determine the clinical outcomes of patients with multivessel disease treated by “contemporary” catheter-based strategy and including stents when indicated, we evaluated procedural success, major in-hospital complications and long-term (one year) clinical events in a large consecutive series of patients undergoing multivessel stenting compared with coronary stent procedure in a single vessel.
Patients and follow up
The patient cohort includes a consecutive series of 2,339 patients (3,633 native coronary lesions) in the Cardiology Research Foundation Angioplasty Database, treated with stents between January 1, 1994 and August 29, 1997. Patients were divided into two groups according to the number of treated vessels (one vs. two or three vessels) during a single intervention session. Among patients with more than one treated vessel, the vast majority (374 of 398 patients, 94%) underwent coronary intervention in two vessels. Patients with two- or three-vessel interventions underwent stent implantation in 672 of 995 (67%) lesions while nonstent procedures were performed in other lesions. All indications for stent use (elective use to improve acute procedural safety and reduce late clinical events, provisional use to treat suboptimal primary device result or urgent use to treat abrupt or threatened closure) are included in this study. Baseline clinical demographics and in-hospital complications were confirmed by independent chart review. Patients with protected or unprotected left-main intervention were excluded from analysis as well as those patients with staged procedures.
All patients underwent preintervention and postintervention 12-lead electrocardiogram (ECG) to detect ischemic changes, appearance of new pathologic Q-waves or both. Blood samples were routinely acquired from all patients every 8 h following the procedure for CK-MB enzyme (normal values, 0 to 4 ng/ml). The diagnosis of non-Q myocardial infarction (MI) was defined as CK-MB elevation ≥5 time normal values, in the absence of new pathologic Q-waves. Clinical outcomes at 1 year were obtained by serial telephone interviews by research nurses and late clinical events (death, Q-wave MI), target lesion revascularization or any cardiac event (death, Q-wave MI, angioplasty or CABG) were adjudicated by accompanying source documentation. In addition to target lesion revascularization, repeat revascularization is also reported per patient (as any repeat revascularization) and includes all target lesion and target vessel revascularizations for single and multiple vessel disease.
Following the initial balloon angioplasty or ablative procedure, coronary stents were implanted over a 0.014″ extra-support guidewire. All stents used during the study period were included in the current analysis. Adjunct high-pressure balloon inflation (14 to 16 atmospheres) was added after initial stent deployment in all cases. Optimal stent implantation was carefully monitored using an iterative technique with prespecified intravascular ultrasound end points in most cases. The prestent and poststent anticoagulation regimens included aspirin (325 mg daily) and ticlopidine (250 mg twice daily) for 1 month, and additional low-molecular-weight heparin (for 2 weeks) in particularly high risk subsets (e.g., thrombus-containing lesions, and patients with ≥3 stents).
We studied 1,920 lesions that were available for complete quantitative and qualitative angiographic analysis. Standard morphologic criteria were used for the identification of lesion location, length, eccentricity, calcification and ulceration. Quantitative angiographic analysis was performed using selected end-diastolic frames demonstrating the stenosis in its most severe projection. Using the contrast-filled guiding catheter as the calibration standard, reference and lesion minimal lumen diameters were determined before and after interventions.
Continuous variables are presented as mean ± 1 SD. Categorical data are presented as percent frequency and compared between groups using chi-square statistics. Survival curves were calculated and displayed using a procedure (SAS® LIFETEST). Wilcoxon statistics were used for survival comparison between groups (one vessel versus multivessel stents). The means of nominal values were compared using the unpaired Student ttest. A p value <0.05 was accepted as statistically significant.
Table 1lists the baseline characteristics of all treated patients, divided according to the number of arteries treated (1 vs. 2 or 3). Overall, patient demographics were similar among groups, except for higher prevalence of previous revascularization procedures (angioplasty and CABG), and recent (within seven days) MI in the single-vessel intervention group. Indications for stenting (i.e., “planned” versus “provisional” versus “urgent”) did not differ between groups (Table 2). Before stent deployment, patients with multivessel disease were treated slightly more often with balloons and less often using ablative devices (Table 2). Overall, the types of stents used and the average number of stents per lesion were similar between groups with most patients in both groups treated with the Palmaz-Schatz stent (Table 2).
Table 3lists the lesion location data for all stented lesions, and qualitative and quantitative measurements available in 1,920 lesions. Multivessel stents were implanted (1) more often in proximal segment, (2) less often in an ostial location and (3) less often in restenotic lesions (15% vs. 27%, p = 0.001). By quantitative angiography, the average pretreatment and posttreatment lesion configurations and quantitative reference and lesion measurements were similar for both groups, as well as the angiographic procedural complications (Table 3).
Overall angiographic and procedural success was high and similar for the two groups (Table 4). Similarly, major in-hospital complications (death, Q-wave MI and emergent CABG rates) were similar for both groups (2.9% vs. 3.8%, p = 0.14). Likewise, the prevalence of periprocedural non–Q-wave MI (CK-MB ≥5 time normal), repeat in-hospital target lesion angioplasty and stent thrombosis was similar for the two groups. However, CK-MB “leak” ≥3 times normal was more frequently associated with multivessel stenting (23% vs. 18%, p = 0.02). The periprocedural use of abciximab (ReoPro) was similar for both groups (4.7% for single-vessel stenting versus 6.1% for multivessel stenting, p = 0.16). A representative case of two-vessel stenting is shown in Figure 1.
Clinical follow-up was available in 1,836 of 1,941 patients (95%) with single-vessel intervention and 378 of 398 patients (95%) with two- or three-vessel intervention (Table 4). There was no difference in late mortality (1.4% for one vessel vs. 0.7% for two or three vessels, p = 0.26). Interestingly, the rate of Q-wave MI was lower for multivessel stenting versus single-vessel stenting (0% vs. 1.2%, p = 0.02). Overall target lesion revascularization at 1 year was 16% for single-vessel intervention versus 15% in multivessel intervention (p = 0.38). Patients with multivessel intervention more often underwent repeat CABG (7.9% vs. 5.0%, p = 0.002) and less often needed repeat coronary angiopasty (6.8% vs. 11%, p = 0.005). The rate of any repeat revascularization was also similar for both groups (20% for a single vessel vs. 21% for two or three vessels, p = 0.73). Likewise, actuarial event-free survival curves for any cardiac event at follow-up (death, Q-wave MI, angioplasty or CABG), was similar for both groups (77% for one vessel vs. 78% for two or three vessels, p = 0.52, Fig. 2).
Comparison to single-vessel disease
Of the patients, 1,549 of the 1,941 (80%) who underwent single-vessel stenting had single-vessel coronary disease. A separate analysis was performed to explore potential differences in clinical outcomes for those patients compared with those undergoing multivessel interventions. Major in-hospital complications were similar for both groups (2.6% vs. 2.9%, p = 0.56). At follow up, there was no difference in death (1.4% vs. 0.7%, p = 0.25) or Q-wave MI (1.5% vs. 0%, p = 0.63) between groups (one vessel vs. multivessels, respectively). Overall target lesion revascularization (16% vs. 15%, p = 0.47), any repeat revascularization (20% vs. 21%, p = 0.46) and cardiac event-free survival (78% vs. 78%, p = 0.89) were similar between groups (one vs. two- or three-vessels).
Logistic regression analysis was used to identify independent predictors for cardiac events (death, Q-wave MI, angioplasty or CABG), target lesion revascularization and any repeat revascularization following coronary stenting in native vessels (Table 5). Variables included in the model were number of treated vessels, number of stents implanted (1 or 2 vs. ≥3), unstable angina, age, gender, previous coronary angioplasty, previous CABG, diabetes mellitus, left ventricular ejection fraction, proximal segment reference vessel diameter and final % diameter stenosis. Unstable angina (1.39), diabetes (1.38), history of CABG (1.37), previous coronary angioplasty (1.63) and reference vessel diameter (0.77) were independent predictors of cardiac event at follow up. Unstable angina (1.26), diabetes mellitus (1.48), history of angioplasty (1.84) and reference vessel diameter (0.55) were predictors of target lesion revascularization. The predictors for any repeat revascularization were similar in addition to prior CABG (1.38) (Table 5). The number of treated vessels or stents was not an independent predictor for the examined cardiac end points.
This study shows that patients undergoing nonstaged multivessel coronary intervention using stents in native coronary arteries have (1) similar in-hospital procedural results and major complications and (2) similar long-term (one year) cardiac events, target lesion revascularization and any repeat revascularization rates compared with single-vessel stent interventions. In this large patient cohort, we also identified independent predictors for subsequent cardiac events or repeat revascularization following stent interventions; unstable angina, prior angioplasty or CABG, diabetes mellitus and reference vessel diameter were associated with clinical events in our multivariate model. Interestingly, the number of vessels treated or stents used did not associate with adverse cardiac end points. Those data are in accordance with our recent publication, using multiple stents to treat single coronary lesions (12). Thus, unlike previous nonstent angioplasty experiences, stenting may be a viable therapeutic alternative to CABG in carefully selected patients with multivessel (i.e., primarily two-vessel) coronary disease.
Previous multivessel angioplasty experiences
Coronary angioplasty or CABG has been indicated for the treatment of multivessel coronary disease (13). The results of (nonstent) multivessel angioplasty series showed variable procedural success rates (82% to 95%), in-hospital mortality (0.4% to 2.8%), MI (0.6% to 4.8%) and emergent CABG (1.4% to 6.9%) (14–20). Long-term results were associated with relatively high repeat revascularization rates (30% to 54%), and cardiac event-free survival was 64% to 74% (14–20). Pooled data comparing coronary angioplasty with CABG in patients with multivessel disease found equivalent nonfatal MI and death rates at follow up (8). However, patients undergoing multivessel angioplasty had significantly more angina, repeat revascularization (mainly target lesion revascularization) and worse quality of life compared with CABG-treated counterparts (8). Moreover, according to the Bypass Angioplasty Revascularization Investigation (BARI) trial (21), diabetic patients with multivessel disease had better survival when treated with surgery. This led to the notion that coronary angioplasty may not be an optimal therapy for multivessel disease primarily in patients with diabetes mellitus (22). However, those studies did not include “contemporary” angioplasty techniques in the catheter-based treatment arms. Because no stent strategy was available in those trials, the need for in-hospital CABG was relatively high (5% to 10%), as well as the clinical restenosis rates (37% to 55%) (14–20). Those results are less favorable compared with our own experience and that of others (23,24).
Multivessel stent experiences
Laham and colleagues (23)reported the results of multivessel stenting in 103 patients (212 vessels including saphenous vein grafts). Angiographic success was achieved in 99%, mortality was 1% and Q-wave and non–Q-wave MI rates were 2% and 11%. Importantly, no patients required emergent CABG. The long-term (13 months) results showed mortality and MI in 4% each. Target vessel revascularization was 17% (only 9% at the stent site). Importantly, no patient required CABG at follow-up and event-free survival was 79%.
Moussa and colleagues (24)reported the results of 100 patients undergoing multivessel coronary stenting with angiographic success achieved in 97% and hospital mortality of 1%. In-hospital CABG rate was 2%, Q-wave MI occurred in 2% and non–Q-wave MI occurred in 6%. During follow up, the mortality rate was 4%, the CABG was 2% and target vessel revascularization was 30%.
Despite differences in patient demographics and method of analysis between the studies, those single-center experiences are consistent in showing favorable short- and long-term results and particularly in comparison to “historical” angioplasty experiences in multivessel disease. These results altogether suggest that multivessel stenting in appropriately selected patients may be a viable therapeutic strategy for patients with multivessel coronary disease.
In this study, there was relatively high level of CK-MB elevation in both treated groups (one vs. two or three vessels). When we used a threshold of ≥5 times normal, there was no apparent difference between the study groups (13% vs. 15%). However, when the threshold was set at ≥3 times normal, a higher frequency of CK-MB “leak” (23% vs. 18%) was found among patients with multivessel interventions. This high prevalence of periprocedural “intermediate” CK-MB elevation probably reflects a cumulative microembolization from multiple treated lesions into larger myocardial territory. However, our preliminary long-term experience did not indicate higher mortality, Q-wave MI or repeat revascularization among patients with multivessel interventions despite their having higher prevalence of procedural “intermediate” CK-MB rises. Also, based on our data, late myocardial adverse coronary events after stenting have been associated only with highest CK-MB elevation (≥5 normal) in native and saphenous vein graft disease (25,26).
Several limitations of our study should be mentioned. First, this is a retrospective study rather than a prospective randomized clinical trial designed to assess the efficacy of stents in patients with multivessel disease. As such, our patient cohort does not include patients with multivessel disease who (a priori) were considered to be better candidates for CABG. Those include patients with diffuse three-vessel disease particularly with diffuse left anterior descending involvement, patients with multiple long (>20 mm) lesions and/or small-sized (<3.0 mm) vessels, those with incessant restenosis or diffuse in-stent restenosis in the context of multivessel disease and patients with unsuccessful catheter-based revascularization approach. Also, it should be emphasized that the vast majority of our patients underwent angioplasty in two (rather than three) vessels. Therefore, the favorable results that we report herein are not necessarily applicable for larger groups of patients with three-vessel coronary disease. It should also be indicated that patients in the single-vessel arm of the study were much more likely to be part of protocols that mandated follow-up angiography as a function of our heavy enrollment into stent protocols. This would tend to increase the detection of restenosis and naturally lead to higher revascularization rates in the single-vessel arm of the study. Finally, the current analysis does not include patients undergoing multivessel stent intervention in saphenous vein grafts. Because this patient population may differ in their baseline demographics and clinical outcomes, we have elected to address the issue of multivessel vein graft interventions in a separate study.
Unlike previous conventional angioplasty experiences, multivessel interventions using stents (primarily in patients with two coronary intervention) have (1) similar in-hospital procedural success and major complication rates, and (2) similar long-term (one-year) clinical outcomes compared with single-vessel stenting (death, MI and repeat revascularization rates). Thus, multivessel coronary intervention, using stents as indicated, does not confer incremental procedural complications or repeat revascularization risk compared with single-vessel treatment. Therefore, stenting may be the preferred therapeutic strategy in carefully selected patient candidates with multivessel coronary disease.
☆ This study was supported by a grant from the Cardiology Research Foundation, The Washington Cardiology Center, Washington, D.C.
- coronary artery bypass graft
- myocardial infarction
- Received May 14, 1998.
- Revision received August 21, 1998.
- Accepted October 6, 1998.
- American College of Cardiology
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