Outcomes of Unprotected Left Main Percutaneous Coronary Intervention: A Single-Centre Experience

INTRODUCTION: When the baseline anatomical syntax score-I (SxSI) is more than or equal to 33, percutaneous coronary intervention (PCI) of unprotected left main (UPLM) is discouraged and considered as high-risk of adverse cardiac events. We designed this study to compare the outcomes of UPLM-PCI between the low to intermediate-syntax score (SxSI(low)/(int).) group (defined as SxSI <33) and the high-syntax score (SxSI(high)) group (defined as SxSI more than or equal 33) with a subanalysis to explore the predictive role of intravascular images (IVI). METHODS: The study is a retrospective observational analysis in a prospective cohort. The prospectively gathered data of consecutive patients, who were enrolled from January 2018 to December 2018, were analyzed at 1-year regarding the primary outcome of major adverse cardiovascular and cerebrovascular events (MACCE). An independent committee calculated the SxSI and reviewed all the events. RESULTS: Baseline data of 2144 patients were considered for analysis. 1245 underwent PCI and 32 (2.57%) had PCI of UPLM; of these, 24 (75%) were in SxSI(low)/(int.) group and 8 (25%) in SxSI(high) group. The mean SxSI was 20.3 ± 6.5 and 37.1 ± 4.9 for SxSI(low)/(int.) and SxSI(high) groups, respectively. Compared with patients in the SxSI(low)/(int.), patients in SxSI(high) group had a greater syntax score-II (<0.0001), which reflects the expected 4-year mortality after PCI by combining the SxSI and clinical variables. Interestingly, despite the fact that the proportion of subjects who sustained MACCE was almost three times more among the SxSIhigh compared to their SxSIlow/int. counterparts [1 (12.5%) vs. 1 (4.2%), P = 0.444], this difference was not statistically significant. It was noted that a higher proportion of patients in whom intravascular imaging (IVI) was not used to guide PCI sustained MACCE compared with that in whom IVI was utilized (2 [50%] vs. [0%], P = 0.012). There is a strong, negative, statistically significant association between the use of IVI and the occurrence of MAACE (Phi=-0.681), which reflects that the use of imaging is associated with significantly lower probability of developing MACCE. CONCLUSION: As demonstrated in this real-world cohort, PCI of UPLM provides excellent outcome at one year regardless of the initial anatomical syntax score. Furthermore, it appears that IVI utilization during the index PCI procedure of UPLM is a potent and independent predictor of MACCE.