Serum Albumin as a Predictor of Pulmonary Embolism Severity: A Retrospective Study From Buraydah, Saudi Arabia.

Background Pulmonary embolism (PE) presents with a wide spectrum of severity, and the early identification of high-risk patients is essential for improving outcomes. Serum albumin has emerged as a potential prognostic biomarker for cardiovascular and thromboembolic diseases; however, its relationship with PE severity and clinical risk scores remains unclear. This study aimed to evaluate the association between serum albumin levels and PE severity, including massive PE, Pulmonary Embolism Severity Index (PESI) scores, and mortality in a tertiary hospital cohort. Methodology This retrospective study was conducted at King Fahad Specialist Hospital in Saudi Arabia between 2022 and 2025 and included 166 adult patients diagnosed with PE. Data on clinical characteristics, comorbidities, hemodynamic parameters, albumin values, troponin values, echocardiographic findings, CT pulmonary angiography, and outcomes were collected. The patients were categorized into five classes according to their PESI score. Furthermore, patients were categorized into massive and submassive/non-massive PE groups. Multivariate logistic regression was used to identify independent predictors of massive PE. Correlation analysis was used to assess the relationship between albumin and the PESI score, and receiver operating characteristic (ROC) analysis was used to evaluate the discriminatory performance of albumin for predicting massive PE. Results The mean age was 57.1 ± 19.4 years, and 93 (56.0%) patients were female. Massive PE was observed in 25 patients (15.1%). Hypoalbuminemia independently predicted massive PE (adjusted odds ratio (AOR) = 13.615, 95% confidence interval = 3.070-60.385; p = 0.001). Right ventricular (RV) strain (AOR = 9.781, p < 0.001) and prior stroke (AOR = 5.340, p = 0.009) were also significant predictors. There was a significant inverse correlation between albumin levels and PESI scores (r = -0.382, p < 0.001). The ROC analysis yielded an AUC of 0.628 (p = 0.005), with an optimal cutoff of 31.9 g/L (sensitivity = 84.8%; specificity = 58%). Mortality was significantly associated with albumin levels (p = 0.035). Conclusions The serum albumin level is a biomarker associated with PE severity, hemodynamic compromise, and adverse outcomes. Hypoalbuminemia independently predicted massive PE and showed a significant inverse correlation with PESI score, underscoring its value in risk stratification. The albumin level was also significantly associated with mortality, suggesting its broader prognostic relevance in acute PE. In models that assess multiple parameters, albumin demonstrated an independent association with PE severity alongside other clinical variables. These results need to be confirmed in prospective multicenter studies, and the mechanistic role of albumin in PE severity and mortality needs to be defined.