Association of Preprocedural SYNTAX Score With Outcomes in Impella-Assisted High-Risk Percutaneous Coronary Intervention

Background: Patients with complex coronary artery disease, as defined by high SYNTAX scores, undergoing percutaneous coronary intervention (PCI) have poorer outcomes when compared with patients with lower SYNTAX I scores. This study aimed to assess if mechanical circulatory support using Impella mitigates the effect of the SYNTAX I score on outcomes after high-risk percutaneous coronary intervention (HRPCI). Methods: Using data from the PROTECT III study, patients undergoing Impella-assisted HRPCI between March 2017 and March 2020 were divided into 3 cohorts based on SYNTAX I score—low (≤22), intermediate (23-32), and high (≥33). Procedural and clinical outcomes out to 90 days were compared between groups. Multivariable regression analysis was used to assess the impact of SYNTAX I score on major adverse cardiovascular and cerebrovascular events (MACCE) at 90 days. Results: A total of 850 subjects with core laboratory–adjudicated SYNTAX I scores were identified (low: n = 310; intermediate: n = 256; high: n = 284). Patients with high SYNTAX I scores were older than those with low or intermediate SYNTAX I scores (72.7 vs 69.7 vs 70.1 years, respectively; P < .01). After adjustment for covariates, high SYNTAX I score remained a significant predictor of 90-day MACCE (hazard ratio [HR], 2.14; 95% CI, 1.42-3.69; P < .01 vs low), whereas intermediate SYNTAX I score was not (HR, 0.92; 95% CI, 0.47-1.77; P = .80 vs low). These findings persisted after adjustment for post-PCI SYNTAX I score. Conclusions: A high SYNTAX I score was associated with higher rates of 90-day MACCE in patients who underwent Impella-assisted HRPCI. Further research is needed to understand the patient and procedural factors driving this finding.