Monoclonal gammopathy of undetermined significance predicts long-term mortality after cerebral infarction: a propensity-matched cohort study

Monoclonal gammopathy of undetermined significance (MGUS) has been associated with thromboembolic and cardiovascular complications; however, its prognostic significance in patients with cerebral infarction (CI) remains unclear. This study investigated the association between MGUS and long-term outcomes in CI and evaluated the predictive value of MGUS for CI prognosis. In this retrospective propensity score-matched cohort study, 60 CI patients with MGUS and 360 matched CI patients without MGUS were enrolled from Zhongshan Hospital. Patients were followed for a median of 5.8 years, with all-cause mortality as the primary endpoint. Kaplan–Meier survival analysis and Cox proportional hazards models were applied to assess prognostic associations. A prognostic nomogram was developed in a training cohort and validated in an independent test cohort. Patients with CI and concomitant MGUS exhibited significantly higher all-cause mortality compared with those without MGUS (log-rank p = 0.017). After adjustment for confounding variables, MGUS remained independently associated with increased mortality risk (hazard ratio 2.47; 95% CI 1.25–4.90; p = 0.009). A nomogram incorporating MGUS, age, modified Rankin Scale score, and D-dimer demonstrated strong discrimination, with C-indices of 0.837 in the training set and 0.792 in the validation set. MGUS is independently associated with poor long-term prognosis in patients with cerebral infarction. Incorporation of MGUS into prognostic assessment improves risk stratification and may inform individualized management strategies for CI patients.