Nomogram prediction of acute kidney injury following modified Morrow myectomy in hypertrophic obstructive cardiomyopathy: insights from 12 years of outcomes

OBJECTIVE: This study explored the incidence and risk factors of acute kidney injury (AKI) in patients with hypertrophic obstructive cardiomyopathy (HOCM) undergoing modified Morrow septal myectomy and developed a risk prediction model to optimize perioperative management. METHODS: A retrospective cohort of HOCM patients who underwent modified Morrow procedure between 2012 and 2024 was analyzed. AKI was defined using Kidney Disease: Improving Global Outcomes (KDIGO) criteria, and patients were grouped into AKI and non-AKI cohorts. Univariate analysis followed by binary logistic regression identified independent predictors of AKI, which informed the development of a nomogram-based prediction model. Model performance was assessed using the concordance index (C-index), calibration curves, and decision curve analysis. RESULTS: Among 270 patients, 54 (20%) developed AKI, including 24, 12, and 18 patients classified as stage 1, stage 2, and stage 3 respectively, with 15 requiring hemodialysis. Independent predictors included preoperative creatinine (OR = 1.069, P < 0.001), postoperative 48-h alanine aminotransferase (ALT) (OR = 1.001, P = 0.021), total bilirubin (TBIL) (OR = 1.036, P = 0.015), pulmonary infection (OR = 9.432, P < 0.001), and red blood cell transfusion (OR = 1.246, P = 0.002). The logistic model achieved 81.13% sensitivity, 87.91% specificity, and an AUC of 0.904 (95% CI: 0.862 ~ 0.936). The nomogram showed excellent accuracy, with a C-index of 0.890. CONCLUSION: AKI is a frequent and severe complication after modified Morrow myectomy in HOCM. Identifying high-risk patients and addressing modifiable factors may improve perioperative management and outcomes.