Incidental pulmonary embolism in cancer and noncancer patients: Prospective cohort study

Abstract

Background: Clinical picture and outcome of incidental pulmonary embolism (iPE) compared to symptomatic pulmonary embolism (sPE) remain unclear.Methods: Demographics, recurrent venous thromboembolism (VTE), mortality, major bleeding, and clinically relevant nonmajor bleeding (CRNMB) were compared between iPE and sPE patients who were followed prospectively at Mayo Thrombophilia Clinic (March 1, 2013 to August 1, 2020).Results: Out of 3576 VTE patients, 1417 (39.6%) had PE: 562 (39.7%) iPE and 855 sPE. Patients with cancer were more likely to have iPE (400 iPE vs. 314 sPE) compared to those without cancer (162 iPE vs. 541 sPE). VTE recurrence rate (all per 100 person-years) was similar in all iPE and sPE patients (3.34 vs. 3.68, p = .50), with cancer (4.16 vs. 4.89, p = .370), and without cancer patients (0.89 vs. 2.80, p = .25).Higher mortality observed in all patients with iPE compared to sPE (46.45 vs. 23.47, p < .001) and with cancer (56.41 vs. 45.77, p = .03) became not significant after adjustment for age, antiplatelet therapy, metastases, and cancer location. Noncancer iPE patients had higher mortality (15.95 vs. 7.18, p = .006) even after adjustment (p = .05). The major bleeding rate was also higher in all patients iPE compared to sPE (7.10 vs. 3.68, p = .03), but not after adjustment (p = .974); higher major bleeding rate in noncancer patients (6.49 vs. 1.25, p = .007) remained significant after adjustment (.02). CRNMB rate was similar to iPE and sPE patients.Conclusion: iPE represents a more serious clinical condition compared to sPE as indicated by the higher mortality and major bleeding but these differences reflect underlying comorbidities rather than the seriousness of the embolic event.

Incidental versus symptomatic pulmonary embolism in patients without cancer

“…On the other hand, in the current study, the IPE group had lower PESI scores and less frequent central PE and RV dilation on CT, indicating a less severe form of PE, which was also significantly associated with a lower risk of adverse outcome. For the risk of VTE recurrence in our study, there was no significant difference between IPE and SPE, which was similar to the study by Wysokinska et al 6 These subtle discrepancies in the results the prognostic impact of IPE in noncancer patients need to be validated in future research. Since this retrospective study was conducted with data from a single center, selection bias was inevitable.…”

“…Approximately 29% of the patients were diagnosed incidentally with PE, which was somewhat consistent with a Vascular Medicine 28 (5) recent study by Wysokinska et al where IPE accounted for 23% of noncancer patients with PE. 6 These findings suggest that the incidence of IPE could be non-negligible in noncancer patients. Many patients in the IPE group of our study had provoking risk factors, including immobilization, surgery, and trauma.…”

“…Few studies have reported clinical outcomes of IPE in noncancer patients. The study by Wysokinska et al has compared IPE and SPE in patients with or without cancer, 6 with the IPE group showing a higher mortality than the SPE group in noncancer patients. In that study, nevertheless, the death rate at 3 months, suggestive of short-term prognosis, was not significantly different between IPE and SPE patients.…”

Incidental central pulmonary emboli in outpatients with deep vein thrombosis

“…Previous studies demonstrated that patients could develop large asymptomatic pulmonary emboli, but many of these cohort studies were conducted in patients with known risk factors for developing clots (such as immobilisation, surgery, trauma or known malignancy). [5][6][7][8][9][10][11][12][13][14] Furthermore, many studies describe incidental findings of emboli on computed tomography pulmonary angiography (CTPA) scans done (at least in part) for reasons other than investigation of PE. 13,15 As such, there are few data in the literature assessing the incidence of asymptomatic pulmonary emboli in ambulant outpatients with ultrasound-proven lower limb DVT.…”

“…PE also vary by its location in the pulmonary arteries, which can range from saddle emboli in the pulmonary trunk to clots in the subsegmental pulmonary artery branches. Previous studies demonstrated that patients could develop large asymptomatic pulmonary emboli, but many of these cohort studies were conducted in patients with known risk factors for developing clots (such as immobilisation, surgery, trauma or known malignancy) 5–14 . Furthermore, many studies describe incidental findings of emboli on computed tomography pulmonary angiography (CTPA) scans done (at least in part) for reasons other than investigation of PE 13,15 .…”