Prognostic role of alpha defensin in predicting periprocedural major myocardial injury following elective percutaneous coronary intervention

Background Periprocedural major myocardial injury (pMMI) remains a frequent complication of elective percutaneous coronary intervention (PCI) and is incompletely explained by procedural complexity or ischemic burden alone. Alpha-defensin, a neutrophil-derived peptide, amplifies inflammatory and thrombotic pathways and may contribute to myocardial vulnerability during PCI. Objectives To evaluate whether baseline plasma alpha-defensin levels are associated with the occurrence of mechanically free pMMI following elective PCI. Methods In a prospective cohort of troponin-negative patients undergoing elective PCI, baseline plasma alpha-defensin levels were measured prior to intervention. pMMI was defined according to ESC criteria. Associations between alpha-defensin and pMMI were evaluated using multivariable logistic regression, with alpha-defensin modeled as a continuous variable (per 1000 pg/mL) and in sensitivity analyses using log-transformed values. Results Among 139 patients undergoing PCI, 23 (17.7%) developed pMMI after exclusion of 8 cases with type 4a myocardial infarction. In the primary multivariable model adjusting for baseline cardiovascular risk factors, higher alpha-defensin levels were associated with pMMI (per 1000 pg/mL: OR 1.06, 95% CI 1.00–1.12, p = 0.048). In sensitivity analysis using ln(alpha-defensin), the association remained significant (OR 2.34, 95% CI 1.08–5.10, p = 0.032). Expanded laboratory adjustment modestly attenuated significance without altering effect direction. Conclusions Elevated baseline plasma alpha-defensin levels are associated with increased risk of pMMI following elective PCI. These findings support alpha-defensin as a biologically plausible biomarker of myocardial vulnerability and highlight its potential role in pre-procedural risk stratification.