Serum lactate levels are an independent marker for complications in acute pulmonary embolism: from the PERT registry

Introduction: Serum lactate is a marker for the presence and severity of imbalances between tissue oxygen supply and demand. There are only scare data regarding the significance of arterial lactate in PE patients.

Materials and methods: We prospectively enrolled 570 patients with topographically-confirmed pulmonary embolism, hospitalized in the Sheba Medical Center in Tel-Ha’Shomer during 2016-2019. Patient’s data was collected using an electronic medical record and follow-up interviews via telephone. The combined end point of hemodynamic instability, shock, mechanical ventilation, or need for CPR was prospectively documented during hospitalization as well as 30 days and 1 year mortality.

Results and discussion: The analysis included 399 consecutive patients with available clinical data including venous lactate. The median age was 69 years, and 220 (56%) were female. A mean arterial pressure under 65mmHg was seen in 27 (7%) of cases, and 79 patients (14%) were either defined as suffering from shock during hospitalization or required cardiopulmonary resuscitation (CPR). Median serum lactate levels were 23 mg/dL (IQR 17-33). Patients with lactate levels above median had a higher incidence of a composite end point (31% vs, 15%, p<0.001). Similar findings were seen when adding either the need for escalating therapy, in-hospital mortality or 30-day mortality to the previous composite. One-year mortality was significantly higher in the higher lactate group (19% vs 6%, p<0.001), and a lactate level above 23 mg/dL was independently associated with 1-year mortality in a Cox-regression model adjusted for age, gender, heart failure, shock or need for CPR and a history of malignancy, HR 2.6 (95%CI 1.7-4.1).

Conclusions: Venous serum lactate levels are associated with a myriad of in-hospital adverse outcomes, as well as long-term mortality. Further studies are needed in order to evaluate the possible prognostic role of the change in serum lactate during PE management.