The prognostic value of blood cellular indices in pulmonary embolism

Abstract

Prognostication in acute pulmonary embolism (PE) requires reliable markers. Whilecellular indices such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyteratio (PLR), and systemic immune-inflammation index (SII) appear promising, their util-ity in PE prognostication needs further exploration. We utilized data from the RIETEregistry and the Loyola University Medical Center (LUMC) to assess the prognosticvalue of NLR, PLR, and SII in acute PE, using logistic regression models. The primaryoutcome was 30-day all-cause mortality. We compared their prognostic value versusthe simplified Pulmonary Embolism Severity Index (sPESI) alone. We included 10 085patients from RIETE and 700 from the LUMC. Thirty-day mortality rates were 4.6%and 8.3%, respectively. On multivariable analysis, an elevated NLR (>7.0) was associ-ated with increased mortality (adjusted odds ratio [aOR]: 3.46; 95% CI: 2.60–4.60),outperforming the PLR > 220 (aOR: 2.36; 95% CI: 1.77–3.13), and SII > 1600 (aOR: 2.52; 95% CI: 1.90–3.33). The c-statistic for NLR in patients with low-risk PE was0.78 (95% CI: 0.69–0.86). Respective numbers were 0.66 (95% CI: 0.63–0.69) and 0.68(95% CI: 0.59–0.76) for intermediate-risk and high-risk patients. These findings weremirrored in the LUMC cohort. Among 9810 normotensive patients in RIETE, those scoring0 points in sPESI and with an NLR ≤ 7.0 (35% of the population) displayed superiorsensitivity (97.1%; 95% CI: 95.5–98.7) and negative predictive value (99.7%; 95% CI:99.5–99.8) than sPESI alone (87.1%; 95% CI: 83.9–90.3, and 98.7%; 95% CI: 98.4–99.1,respectively) for 30-day mortality. The NLR is a significant prognostic marker for 30-daymortality in PE patients, especially useful to identify patients with very low-risk PE.