Early and Long-Term Outcomes after Surgical and Percutaneous Myocardial Revascularization in Patients (see full title below)
- Volume 21 - Issue 11 - November, 2009
- Posted on: 11/5/09
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Univariate analysis with odds ratio (OR) stratification (Figure 7A) revealed that CABG (OR = 8.1; 95%, confidence interval [CI] = 1.01–66.5), diabetes mellitus (OR = 3.98; 95% CI = 1.1–14.9), age > 65 years (OR = 10.2; 95% CI = 1.3–82.9), Euroscore > 5 (OR = 19.5 1.1–338) and Killip 4 Class (OR = 31; 95% CI 2.6–388) were the risk factors that increased 30-day mortality, while PCI was the single factor that decreased the mortality rate (OR 0.12; CI 0.1–0.9).
Multivariate analysis showed that a Euroscore > 5 and CABG were the independent risk factors that increased 30-day mortality.
Mid-term and late outcomes. A control coronary angiogram after 6–12 months was performed in 35 (55.5%) of patients in the PCI group. Within this cohort, restenosis in the LMCA occurred in 4 cases (11.4%).
During the first year, in total there were 4 deaths (6.3%) in the PCI group and 12 (16%) in the CABG group (p = 0.173), including 3 deaths in both groups between 1 month up to 12 months (Figure 2).
There were no significant differences between the PCI and CABG groups in the rate of MACCE (9.5% vs. 9.3%; p = ns), MI (9.5% vs. 5.3%; p = ns), stroke (0% vs. 4%; p = ns) or repeat revascularization (7.9% vs. 4.0%; p = ns) (Figure 3).
Long-term survival (mean follow up 23.7 months) was 86.5% after PCI and 83% after CABG (p = 0.07), as seen on the Kaplan-Meier curve in Figure 4. A trend toward better survival after PCI was primarily due to the early (30-day) high mortality rate in the CABG group. Furthermore, there were no significant differences in long-term MACCE-free survival between those groups (Figure 5).
In the subgroup of patients who presented with a SYNTAX score < 31, PCI was associated with better long-term survival than CABG (Figure 6A). On the other hand, in the subgroup of patients with a SYNTAX score ≥ 31, there were no differences between the groups (Figure 6B).
Analysis of single risk factors influencing late survival (Figure 7B) showed that diabetes mellitus (OR: 4.9; 95% CI: 1.6–14.6; p = 0.006), age > 65 years (OR: 3.4; 95% CI: 1.04–11.2; p = 0.027) and Euroscore > 6 (OR: 5.5; 95% CI: 1.2–25.1; pM = 0.05) on admission had an impact on survival in these patients. According to multivariate analysis, a Euroscore > 6 on admission was the independent risk factor determining survival over the entire observation period.
This is the first study presenting early and long-term results in patients after LMCA stenting in patients with unprotected LMCA disease and non-ST-ACS. Here we show very promising results after LMCA stenting in this high-risk population.
PCI vs. CABG in stable/unstable angina. Multiple studies have shown that the risk of CABG in patients with ACS and multivessel coronary artery disease is higher than in stable angina patients.11 The ERACI study proved that PCI with stent implantation in a population consisting mainly of ACS patients (90%) is associated with better survival and freedom from MI than after conventional surgery.12,13 In contrast, no significant differences in early or late mortality rates were observed in studies where the majority of enrolled patients had stable angina (ARTS – > 70%).11,14 In the SOS trial (80% of patients with stable angina), 1-year mortality was higher after PCI,11 while 6-year follow up revealed better survival after CABG only in stable angina patients.15 In both of these studies, the high incidence of target vessel revascularization (TVR) remained a major limitation of PCI. It was improved by application of DES stents in the ARTS II trial, with no difference in survival and MACE-free survival between patients with stable and unstable angina after PCI.16
PCI vs. CABG for ULMCA. Previous registries reported a high incidence of perioperative injury and MI in patients with LMCA disease undergoing CABG,17 whereas left main stenting has been associated with a low risk of in-hospital death and MI.1–3
Recently published registries and nonrandomized studies suggest that treatment of ULMCA disease with DES is feasible, resulting in a high procedural success rate and a significant reduction in MACE and restenosis1–3 Chieffo et al reported a significantly lower risk of 6-month MACE if DES were used for ULMCA stenting (20% vs. 35.9% for DES and BMS, respectively).2 These findings are consistent with the RESEARCH and T-SEARCH registries, which showed lower mid-term MACE (24% vs. 45%; p = 0.01) and TVR (6% vs. 23%; p = 0.004) after DES implantation. Our study presents similar results regarding TVR (4.8% in PCI group). Recently, Colombo’s group reported a single-center retrospective study comparing PCI with DES vs. CABG for ULMCA that showed no difference in the degree of protection against death, stroke, MI and revascularization between the two treatment groups.4
Our LE MANS randomized study, published recently, showed a significantly lower risk of 30-day serious adverse events and a trend toward better survival after PCI. Moreover, only in the PCI group did LVEF improve significantly after 12 months.7
In the currently presented new cohort of ACS patients, long-term outcomes were comparable in both groups with respect to the overall MACCE rate, however, there was a trend toward better survival after PCI. This finding corresponds well with the results of Seung et al in their latest MAIN-COMPARE study.5 Similarly, the SYNTAX trial showed comparable 1-year MACCE risk between PCI and CABG in the LMCA subset,18 and in the subgroup of SYNTAX scores between 27–32. Our study consisted mainly of such patients (average SYNTAX Score of 31.2).
PCI vs. CABG in high-risk patients. The AWESOME study showed that PCI is an alternative to CABG for patients with medically refractory myocardial ischemia and a high risk of adverse outcomes with CABG.19 With the onset of new techniques and possibilities, our registry presents more favorable results after PCI in NSTE-ACS patients with unprotected left main disease (1.6% vs. 12% of early MACCE; p = 0.04).
There are no published reports on early mortality after CABG in patients with ULMCA and NSTE-ACS. The only available data showed an 8–33% early mortality rate after CABG in patients with ACS but without severe stenosis of the LMCA.20,21 The early surgical morality rate (12%) observed in our study was consistent with the predicted preoperative risk calculated from the additive and logistic Euroscores,22 which in the CABG group were 7.4 and 11.72%, respectively.
Our study is the first to include patients with the combined high-risk features of NSTE-ACS and ULMCA disease. The results are consistent with prior reports in the literature regarding CABG and PCI for ULMCA disease and reports of these revascularization techniques in NSTE-ACS.
Study limitations. The primary limitations of our study are the relatively small number of enrolled patients and the non-randomized nature of the comparison. This is related to the fact that surgical revascularization is presently considered the treatment of choice for patients with severe narrowing of the ULMCA.23
On the other hand, PCI patients, despite higher Euroscores and similar SYNTAX scores, had lower mortality and total MACE rates. This observation highlights the usefulness of PCI in this high-risk population. Based on our findings, we recommend that a large randomized study with similar inclusion criteria be conducted.
This study demonstrated that left main stenting offered significantly better acute results in NSTE-ACS patients compared to CABG, despite the high-risk profile in the PCI group. After 1 year, the difference in mortality was maintained.