CABG Versus PCI in Multivessel Disease

In a recent study published in The Lancet, it was found that there is a mortality benefit for patients with multivessel disease undergoing CABG compared to PCI. However, the reduction in mortality was not statistically significant in patients with only left main artery disease. With recent advancements in stenting techniques, the benefit of using CABG over PCI has been debatable. Prior to this , no study was powered to compare the mortality benefits between these interventions.

Dr. Stuart Head and his colleagues conducted a pooled analysis of randomized clinical trials, which included 11,518 patients from 11 trials comparing CABG versus PCI with stents. Patients were followed for a period of 4-8 years in which, 976 of 11 518 patients died, providing sufficient power to detect a significant difference in mortality between the interventions. The 5-year incidence of all-cause mortality was 11·2% after PCI versus 9·2% after CABG. On subgroup analysis, no significant difference in 5-year all-cause mortality was observed between the interventions in patients with left coronary artery disease (10·7% after PCI vs 10·5% after CABG). On the other hand, in patients with multivessel disease or comorbid conditions such as those with diabetes, a significant mortality benefit of CABG over PCI was observed (11·5% after PCI vs 8·9% after CABG).

The main strength of this study is that it was conducted by pooling data through the collaboration of 11 high-quality randomized trails. In an email to Cardiology Now, Dr. Stuart J Head, a cardiothoracic surgeon from Erasmus University Medical Center, Rotterdam, Netherlands said, “By pooling these trials, we now have sufficient patients and events to actually find statistically significant differences between CABG and PCI. Moreover, the number of patients is large enough to even look at smaller subgroups which normally in individual trials are severely underpowered.” However, the investigators caution that heterogeneity of the baseline characteristics due to different and trial-specific inclusion and exclusion criteria may serve as a major limitation to its interpretation. In addition to this, mortality was the only outcome considered in the study.

This study demonstrated a significant reduction in  5-year mortality after CABG versus PCI in patients with multivessel disease or comorbid conditions (including diabetes). Moreover, the study also emphasized that the severity of coronary artery disease needs to be considered while planning revascularization techniques. When asked on how these findings can impact clinical practice, Dr. Stuart states that “Although all of the individual trials provide important evidence on the CABG versus PCI debate, this analysis on such a large group of randomized patients really provides the strongest evidence. I expect surgeons and cardiologists in the Heart Team to be more confident in supporting a surgical or interventional approach in specific patients based on these variables since we now have strong data to back up these decisions.” In addition to this, he also expects to see some differences in recommendations for the management of multivessel disease and left main disease based on the results of this study in the new ESC/EACTS revascularisation guidelines that will be published later this year in 2018.