Clinical Analysis Of 119 Patients With Pulmonary Infarction Secondary To Pulmonary Embolism

Objective:Pulmonary embolism is a clinical pathophysiological syndrome caused by blockage of the pulmonary artery and its branches with various emboli,which resulted in pulmonary circulation disorders.Pulmonary infarction is one of the serious complications of pulmonary embolism,and is generally considered as a rare disease in elderly patients with underlying cardiopulmonary issue.However,recent studies found that pulmonary infarction had a trend to occur in younger healthy patients.In order to elucidate the incidence,risk factors,clinical characteristics,diagnosis and treatment,and outcome,this study performed a retrospective analysis of patients with pulmonary infarction secondary to pulmonary embolism in the First Affiliated Hospital of the University of Science and Technology of China.Methods:We collected and analyzed the data of hospitalized consecutive cases of pulmonary infarction diagnosed by computed tomographic pulmonary angiography imaging from January 1,2017 to December 31,2019 in the First Affiliated Hospital of the University of Science and Technology of China(Anhui Provincial Hospital).Statistical software SPSS25.0 was used to analyze the differences between pulmonary infarction patients and non-infarction patients,and identify the clinical characteristics,risk factors and prognosis of pulmonary infarction secondary to pulmonary embolism.Results:In this study,the incidence of pulmonary infarction was 41%(119/289)in patients with pulmonary embolism with a male-to-female ratio of 1.4:1,mean age of 60.0 ± 13.8 years,and mean height of 166.5 ± 7.9 cm.The most common manifestations were chest tightness(70 cases,58.8%),swelling or pain in lower limbs(57 cases,47.9%),and dyspnea(55 cases,46.2%).Incidences of chest pain,hemoptysis and syncope were 27.7%,19.3% and 16.8%,respectively.The ratio of typical triad pulmonary infarction with dyspnea,chest pain and hemoptysis were only 4.2%.The most common signs of pulmonary infarction were vessel sign(100 cases,84.0%)and central lucency(91 cases,76.5%)and Hampton’s Hump sign(46 cases,38.7%).Only 15%(14/92)of the pulmonary infarction cases were diagnosed correctly and the rest 85%(78/92)were mainly misdiagnosed as pneumonia(92%,72/78).Compared with non-infarction group(66.1 ± 12.7 years old),the ages of pulmonary infarction group were younger(60.0 ± 13.8 years old,P<0.001).Prevalence of PI in setting of PE decreased from 80% in 18-30 years group to 18% in above 80 years group.Higher height(166.5 ± 7.9 cm VS 163.4 ± 7.9 cm,P<0.001),chest pain(27.7% VS 11.8%,P = 0.001)and hemoptysis(2.9% VS 19.3%,P <0.001)were more common in pulmonary infarction group with significantly lower prevalence of cardiovascular disease(49.6% VS 65.3%,P = 0.008)than non-infarction group.Compared with non-infarction group,grade 4 pulmonary thrombosis(95.8% VS 88.2%,P = 0.024)and pleural effusion(54.6% VS 24.7%,P<0.001)were more common in pulmonary infarction group.Multivariate binary logistic regression analysis found that pleural effusion(OR = 5.356),hemoptysis(OR = 4.832),grade 4 pulmonary artery thrombosis(OR = 4.152)and height growth(OR = 1.059)were independent risk factors for pulmonary infarction secondary to pulmonary embolism.Compared with patients with pulmonary embolism in 18 – 40 years old group,patients with pulmonary embolism aged ≥81 years had a lower risk of secondary pulmonary infarction.There was no significant difference between the prognosis of pulmonary infarction group and non-infarction group.Patients with pulmonary infarction were discharged and followed up for 6 months without adverse clinical outcomes.The proportion of patients with lesion absorption gradually increased from 19%,31%,41% to 56% during follow-up at eight weeks,12 weeks,16 weeks and 24 weeks,respectively.At 52-weeks follow-up,84.4% patients with pulmonary infarction returned to normal.Conclusions:The incidence of pulmonary infarction was unneglectable in patients with pulmonary embolism,and neither typical triad nor Hampton’s Hump sign was common.Pulmonary infarction was difficult to diagnose,and often misdiagnosed as pneumonia.Pleural effusion,hemoptysis,distal emboli,and height were independent risk factors for pulmonary infarction.The risk of pulmonary infarction was lower in elder patients than that of younger patients.The prognosis was similar to those of noninfarct patients,and the lesions would gradually return to normal in most patients.