5351 - Performance of the ‘4S rule’ to predict short-term outcomes in cancer outpatients with unsuspected pulmonary embolism.

Background

The diagnosis of incidental or unsuspected pulmonary embolism (PE) in cancer outpatients undergoing scheduled CT-scans is a challenge in daily oncological practice. The aim of this study was to assess the performance of the ‘4S rule’ (Setting, Suspicion, Signs and Symptoms) as a PE risk-assessment model in this setting.

Methods

We assessed consecutive patients with cancer-associated PE from an ongoing multicenter observational registry (2005-2018). Patients were classified as presenting ‘Truly asymptomatic unsuspected PE’ (TAUPE) according to the ‘4S rule’ (EurRespir J 2017;49(1):1600282 and EurRespir J 2017;49(1):1602225) that includes the following variables: (1) outpatient Setting at PE diagnosis; (2) no Suspicion of PE; (3) vital Signs within normal limits including blood pressure >100 mmHg, heart rate <100 per minute and oxygen saturation >95%; and (4) absence of PE Symptoms. Short-term outcome measures included: all-cause and PE-related mortality within 30 days after the index PE.

Results

We evaluated a total of 617 patients (61.6% male; median age 65 + 11.4 years) including 207 (33%) with TAUPE, 284 (47%) with ‘acute suspected PE’ and 126 (20%) with ‘unsuspected PE with symptoms’. Most patients (79%) had metastatic cancer and nearly half (47%) were on chemotherapy. The PE was incidentally found in 54% of the cohort. The most frequent tumors were: 32% lung, 14% colorectal, 13% urological, and 12% upper gastrointestinal. All-cause 30-day mortality occurred in 95 patients (15% of the cohort) and 12 cases presented PE-related mortality (2% of the cohort). Patients with TAUPE had lower all-cause 30-day mortality compared to non-TAUPE cases (3% vs. 22%; p < 0.0001). PE-related 30-day mortality occurred in 0 patients with TAUPE and in 12 (3%) non-TAUPE patients (0% vs. 3%; p = 0.013).

Conclusions

Short-term mortality in patients with cancer-associated PE is high. Cancer outpatients with TAUPE according to the 4S rule criteria (33% in the cohort) were identified as a low-risk group of all-cause and PE-related short-term mortality. These findings may help to develop PE risk-assessment models in this setting.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Hospital Clinic de Barcelona.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.