Abstract
We aimed to investigate whether the unusual clinical presentation of pulmonary embolism (PE) varies by the type of provocation. In this retrospective cohort study, we examined the electronic health records (EHR) records of all patients diagnosed with PE (upon presentation or during hospitalization) presented to our tertiary hospital during 2014 to 2019. Inclusion criteria were the diagnosis of acute PE and age above 18 years. Excluded were all patients to whom complete EHR were not available. The primary outcome was the main presenting symptom, categorized by a multidisciplinary consensus expert committee as either typical or atypical of PE. Comorbidities, vital signs, medications and laboratory results on presentations were recorded. 591 patients were included in the final analysis. Dyspnea was significantly less common and hemoptysis and chest pain more common in the unprovoked PE group (35%, 5%, and 25%, respectively) compared with nonmalignant (42.6%, 0%, and 16.3%) and malignancy-associated (47.7%, 0.9%, and 8.2%) PE (Pv = 0.02, 0.002 and 0.001, respectively). No recorded symptoms were the third most common presentation overall, accounting for a significantly (Pv < 0.001) higher proportion of PE patients with malignancy (19%) whereas atypical presentation was the hallmark of patients with nonmalignant provokation (19.7%) (Pv = 0.005). Accounting for multiple potential confounders, the risk of atypical or asymptomatic presentation was higher with lower heart rates (RR = 0.974 95%C.I. [0.957-0.990]) and higher pulse oximetry saturation (RR = 1.114 95%CI [1.034-1.201]). The clinical presentation of PE varies with different types of provoking factors, with atypical presentation most common in nonmalignant provocation and asymptomatic presentation most prevalent in patients with underlying malignancy. Further studies are needed to determine the effect of said variance on long term clinical outcomes.