After the introduction of drug-eluting stents (DESs), percutaneous coronary intervention with DESs has challenged coronary artery bypass grafting as the gold standard for the treatment of 3-vessel coronary artery disease. The purpose of this study was to compare the long-term clinical results between percutaneous coronary intervention with DESs and off-pump coronary artery bypass grafting (OPCAB) in 3-vessel coronary artery disease. Two hundred ninety propensity-score matched patients with 3-vessel coronary artery disease treated by DESs or OPCAB were included. Mean follow-up duration was 58.8 ± 11.5 months (2 to 73) and follow-up rate was 97.9%. Five-year survival rates were 94.8 ± 2.1% in the DES group and 96.5 ± 1.5% in the OPCAB group (p = 0.658). Five-year rates of freedom from major adverse cardiac and cerebrovascular event were 71.6 ± 4.1% in the DES group and 89.6 ± 2.5% in the OPCAB group (p <0.001). Freedom from nonfatal myocardial infarction and target vessel revascularization rates were the determining factors between the 2 groups (p = 0.018 and p <0.001, respectively). The OPCAB group showed better clinical outcomes compared to the DES group in 3-vessel coronary artery disease after 5-year follow-up. Freedom from major adverse cardiac and cerebrovascular event rate was significantly higher in the OPCAB group mainly because of the lower incidence of target vessel revascularization and nonfatal myocardial infarction. Longer follow-up with randomization will clarify our present conclusions.
After the introduction of drug-eluting stents (DESs), numerous studies have compared the clinical results between coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) with DESs and most of those studies have shown a better clinical outcome in patients after CABG especially in the reintervention rate. Despite the benefits of surgical revascularization over PCI, the PCI attempt rate increased after widespread use of DESs. Several randomized trials comparing PCI with bare-metal stents to CABG have published long-term clinical results showing similar survival rates with higher revascularization rate in patients with PCI, whereas others have shown a long-term survival advantage in the surgical group. Few long-term results have been published on clinical outcome comparing PCI with DESs to off-pump coronary artery bypass grafting (OPCAB). As DES use has improved the restenosis rate in the PCI field, OPCAB has decreased major complications after surgical revascularization. The purpose of this study was to compare long-term clinical results between OPCAB and PCI with DESs, which are the most advanced revascularization strategies in surgical and medical coronary revascularization of 3-vessel coronary artery disease. Our group previously reported the early results. In the present study we aimed to evaluate long-term clinical results focusing on major adverse cardiac and cerebrovascular events (MACCEs).
Methods
From July 2003 to June 2005, 508 patients with 3-vessel coronary artery were initially treated by OPCAB (n = 241) or by PCI with DESs (n = 267). After propensity matching of patients, 145 patients were enrolled in the OPCAB group and in the DES group. Not being a randomized study, the propensity-score matching method was used for patient matching and the following factors were considered for analysis: gender, age, hypertension, diabetes mellitus, acute coronary syndrome, left main coronary artery disease, left ventricular ejection fraction (percentage), chronic obstructive pulmonary disease, peripheral artery occlusive disease, chronic renal failure, stroke history, old myocardial infarction, and carotid disease.
After patient matching the 2 groups showed similar patient characteristics ( Table 1 ). We compared overall and annual MACCEs and the primary end points were any MACCE during the follow-up period. Approval of the institutional review board of Gangnam Severance Hospital was obtained for data collection and follow-up and individual patient consent was waived.
| Variables | DES Group (n = 145) | OPCAB Group (n = 145) | p Value |
|---|---|---|---|
| Age (years) | 62.6 ± 10.0 | 62.7 ± 9.3 | 0.976 |
| Women | 39 (26.9%) | 41 (28.3%) | 0.793 |
| Diabetes mellitus | 68 (46.9%) | 68 (46.9%) | 1.000 |
| Hypertension | 86 (59.3%) | 85 (58.6%) | 0.826 |
| Chronic obstructive pulmonary disease | 0 | 0 | — |
| Acute coronary syndrome | 86 (59.3) | 81 (55.9%) | 0.405 |
| Chronic renal failure | 4 (2.7%) | 3 (2.1%) | 0.525 |
| Cerebrovascular accident | 12 (8.3%) | 15 (10.3%) | 0.544 |
| Peripheral artery occlusive disease | 29 (20.0%) | 26 (17.9%) | 0.653 |
| Left main coronary artery disease | 18 (12.4%) | 20 (13.8%) | 0.616 |
| Left ventricular ejection fraction (%) | 57.3 ± 13.9 | 56.7 ± 12.7 | 0.694 |
| Carotid disease | 7 (4.8%) | 11 (7.6%) | 0.330 |
In the OPCAB group all patients underwent conventional sternotomy. The left internal thoracic artery was used in all patients and bilateral internal thoracic arteries were used in 69 (47.6%). Total arterial grafting was performed in 64 patients (44.1%) and mean distal anastomosis number was 3.34 ± 0.38 (2 to 5) per patient. In most patients we used the left internal thoracic artery for the left anterior descending coronary artery and a radial artery composite graft for the other left coronary artery systems. For the right coronary system, we used the right internal thoracic artery or a free saphenous vein according to the degree of native coronary artery stenosis. All patients received aspirin (100 mg/day) and clopidogrel (75 mg/day; Plavix; Sanofi, New York, New York) from the day of operation unless contraindicated. Dual antiplatelet therapy was maintained until 9 months after surgery unless contraindicated. During the study period all patients received statins postoperatively.
In the DES group each patient received ≥1 DES during the procedure. During the study period 2 commercially available DESs were used by randomization (Cypher, Johnson and Johnson, Miami, Florida; and Taxus, Boston Scientific Corp., Natick, Massachusetts). Aspirin (100 mg/day) and clopidogrel (300-mg loading dose the day before the procedure and 75 mg/day thereafter; Plavix; Sanofi) were maintained for 9 months after stent implantation.
Patient follow-up was done by patient interview in an outpatient clinic or by telephone from March 2010 to July 2010. Follow-up loss was defined as a patient who could not be contacted during this period. Information on death was also confirmed by the database of the Korea National Statistical Office. Details of definitions are described in our previous article. A MACCE was defined as the occurrence of death from any cause, nonfatal myocardial infarction, stroke, and target vessel revascularization. The follow-up period was 58.8 ± 11.5 months (2 to 73) and the follow-up rate was 97.9%. Six patients were lost to follow-up including 3 patients who went abroad.
For comparison of 2 variables, unpaired t test and chi-square test were used and continuous variables were expressed as mean ± SD. Times to death and an event were compared using the Kaplan–Meier method and log-rank test. Significance was defined as a p value <0.05. Statistical analyses were performed using SPSS 13.0 (SPSS, Inc., Chicago, Illinois).
Results
There were 6 deaths (4.1%) in the DES group and 5 deaths (3.4%) in the OPCAB group during the follow-up period (p = 0.759). Five-year survival rates were 94.8 ± 2.1% in the DES group and 96.5 ± 1.5% in the OPCAB group (p = 0.658; Figure 1 ) .
Overall MACCE rates were 25.5% in the DES group (n = 37) and 10.3% in the OPCAB group (n = 16, p = 0.001). Five-year rates of freedom from MACCEs were 71.6 ± 4.1% in the DES group and 89.6 ± 2.5% in the OPCAB group, with a significantly higher rate in the OPCAB group (p <0.001; Figure 2 ) .
Overall nonfatal myocardial infarction incidences were 3.4% in the DES group (n = 5) and 0% in the OPCAB group (p = 0.025) and 5-year rate of freedom from myocardial infarction was 96.0 ± 1.8% in the DES group, which was significantly lower compared to the OPCAB group (p = 0.018; Figure 3 ) . The stroke incidence was 2.8% (n = 4) in the 2 groups (p = 1.000). Five-year rates of freedom from stroke were 96.7 ± 1.6% in the DES group and 97.1 ± 1.4 in the OPCAB group (p = 0.857; Figure 3 ). For target vessel revascularization, there were 27 events in the DES group and 7 events in the OPCAB group (18.6% and 4.8%, respectively, p <0.001). Five-year rates for freedom from target vessel revascularization were 72.0 ± 4.4% in the DES group and 94.9 ± 1.9 in the OPCAB group, with a significantly higher rate in the OPCAB group (p <0.001; Figure 3 ).
