No difference was observed in the occurrence of death, cerebrovascular accidents and MI between PCI and CABG in the multinational all-comers DELTA Registry for unprotected left main coronary artery (ULMCA) stenosis. However, an advantage of CABG over PCI was observed in the incidence of major adverse cardiac and cerebrovascular events (MACCE), driven by the higher incidence of target vessel revascularization with PCI.
PCI for ULMCA lesions has a Class IIb indication in high-risk surgical patients, according to the guidelines (J Am Coll Cardiol 2009;54:2205-2241). While some single-center studies and multicenter registries have indicated that PCI has noninferior outcomes to CABG, there is no definitive answer about how the procedure compares with CABG for this patient population in a real-world setting.
Antonio Colombo, MD, of the department of cardiothoracic and vascular diseases at the San Raffaele Scientific Institute in Milan, Italy, and colleagues analyzed all consecutive patients with ULMCA stenosis treated by PCI with DES versus CABG in this multinational registry. They performed a propensity score analysis to adjust for baseline differences in the overall cohort. Their study results were published in the July issue of the Journal of the American College of Cardiology: Coronary Interventions.
In total, 2,775 patients were included: 1,874 were treated with PCI vs. 901 with CABG. At 1,295 days, there were no differences, at the adjusted analysis, in the primary composite endpoint of death, cerebrovascular accidents, and MI, mortality or composite endpoint of death and MI. An advantage of CABG over PCI was observed in the composite secondary endpoint of MACCE, driven exclusively by the higher incidence of target vessel revascularization with PCI.
The main findings of this multinational “all-comers” registry are:
- No difference was found at a median follow-up of 1,295 days in the occurrence of the primary endpoint (death, MI, and cerebrovascular accident [CVA]) between PCI with DES implantation and CABG for ULMCA disease both in the propensity analysis as well as in the propensity matched analysis;
- There is still an advantage of CABG over PCI in terms of MACCE that is exclusively driven by a lower incidence of repeat revascularization;
- PCI in this particular subset of patients can be considered a safe procedure, and this is testified to by the low occurrence of ST and mortality despite the all-comers design; and
- Age, left ventricular ejection fraction, EuroSCORE, SYNTAX score, emergency procedures and need for hemodynamic support were found to be correlated to the occurrence of death, MI and CVA.
In the study, there was a significant difference in SYNTAX scores between the PCI and CABG groups (28.6 vs. 38.9, respectively). “Interestingly, in such experienced centers, the extent of coronary artery disease guided the choice of the treatment even before the introduction of the SYNTAX score, with the SYNTAX trial that reported worse clinical outcome in the subgroup of patients with a score less than 33,” the authors wrote. “Clearly, the application of the SYNTAX score gives credibility to our practice, helping the operator and referring physician to decide upon the optimal therapeutic option in this subset of patients.”
There were three limitations indicated in the study. The major limitation was it was an observational study. Also, because of the retrospective nature of the study, the researchers could not analyze all the baseline angiography films to calculate the SYNTAX score in all patients (overall 2,064 of 2,775 films were analyzed). Also, it was not possible to calculate the rate of symptomatic graft occlusion in the CABG group. Further limitations are the length of clinical follow-up and the type of stent used.
“Rates of repeat revascularization were still higher among patients who underwent PCI than among those who underwent CABG,” Columbo et al acknowledged in their conclusion. “In selected cases and in highly competent tertiary centers, PCI for ULMCA disease can be considered a safe and effective procedure, with encouraging results at long-term follow-up, and might possibly be considered a feasible alternative to CABG.”