Risk factors for mechanical complications in very elderly patients with acute myocardial infarction

Luqin Yan^1*Wei Yuan²Tao Shi^1*

• ¹Department of Cardiovascular Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi'an, China
• ²Department of Cardiovascular Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China

Background: The mortality rate for mechanical complications in very elderly acute myocardial infarction (AMI) patients is extremely high, but predictive tools specifically for this population are lacking. Methods: Mechanical complications (free-wall rupture, ventricular septal rupture, papillary muscle rupture/dysfunction, ventricular aneurysm) were independently validated. Differences in baseline characteristics, laboratory markers, and outcomes were compared. Missing data underwent sensitivity analysis, with >20% exclusion and <15% imputation. Regression modeling entered variables with univariate association (P < 0.05) or clinical relevance into multivariable logistic regression; final model derived via backward elimination (P < 0.05 retained) with VIF >5 exclusion. Analyses used SPSS/GraphPad (two-tailed P < 0.05). Results: This retrospective cohort study analyzed 2467 consecutive AMI patients aged ≥ 75 years. Mechanical complications occurred in 9.6% (n = 236) of patients. Ventricular aneurysm (VA) predominated (92.8%), strongly associated with anterior infarcts (71.2%, P < 0.001) and reperfusion (81.7%, P < 0.001). Rupture complications favored non-reperfused infarcts. Patients with mechanical complications exhibited distinct profiles: lower systolic blood pressure (115.9 vs 123.5 mmHg, P = 0.001), higher STEMI prevalence (60.6% vs 44.1%, P < 0.001), advanced Killip class III-IV (22.5% vs 13.3%, P < 0.001), and biomarker evidence of intense inflammation (elevated WBC, neutrophil%, hs-CRP), myocardial injury (higher cTnT, NT-proBNP), and metabolic derangements (hypoalbuminemia, hyperkalemia). Multivariable analysis identified independent predictors: Killip class III/IV (OR=2.99), elevated neutrophil percentage (OR=1.05), hyperkalemia (OR=1.70), and hypoalbuminemia (OR=0.92). A history of hypertension was paradoxically protective (OR=0.50). Conclusion: This study identifies ventricular aneurysm as the dominant mechanical complication in very elderly AMI patients, establishes a paradoxical protective role of hypertension history, and proposes a distinct risk profile integrating hemodynamic status, neutrophilic inflammation, and metabolic derangement. These findings are hypothesis-generating and highlight a potentially valuable stratification tool that warrants prospective validation in external cohorts before clinical application.