(1) Background: Frailty is a condition associated with aging, co-morbidity, and disability. We aimed to investigate the relationship between frailty and in-hospital outcome in patients with myocardial infarction (MI), including the occurrence of delirium, hospital-acquired pneumonia (HAP), and length of hospital stay. (2) Methods: We analyzed 55 patients ≥ 75 years old with ST-elevation and non-ST-elevation MI. Assessment with Abbreviated Mental Test Score (AMTS), Activity of Daily Living (ADL), Instrumental Activity of Daily Living (IADL) and Clinical Frailty Scale (CFS) was performed. (3) Results: In ROC analysis, IADL and CFS presented good predictive values for the occurrence of delirium (AUC = 0.81, p = 0.023, and AUC = 0.86, p = 0.009, respectively). For predicting HAP, only AMTS showed a significant value (AUC = 0.69, p = 0.036). In regression analyses, all tests presented significant predictive values for delirium. For predicting HAP, only IADL and CFS presented significant values (in an analysis adjusted for age, gender and type of MI). Frail patients (≥5 points in CFS) had longer hospital stays (10 days IQR: 8-17 vs. 8 days IQR: 7-10; p = 0.03). (4) Conclusions: While recognizing the limitations of our study associated with the relatively low sample size, we believe that our analysis shows that frailty is a predictor of poorer in-hospital outcomes in patients with MI, including higher rates of delirium, HAP and longer hospital stay.
Keywords: delirium; frailty; hospitalization length; myocardial infarction; pneumonia.