Pulmonary embolism in younger and older adults: clinical presentation and comparison of right ventricular dysfunction, a new prognostic echocardiographic index

Introduction

Previous reports suggested that clinical presentation of pulmonary embolism (PE) could be different in younger as compared with older patients and the presence of right ventricular dysfunction (RVD) at echocardiography could identify a group of PE patients with poor short-term prognosis. We tested these hypotheses and compared in these two groups a new prognostic echocardiographic index: the RVD.

Methods

This is an observational retrospective study of 80 consecutive patients (40 younger, age ≤ 45 years; 40 older, age > 45 years) admitted to the ED of an urban hospital from January 1996 to June 2003 for suspected PE, confirmed by high-probability lung scan and/or spiral CT. All patients had symptomatic PE and SBP ≥ 100 mmHg at presentation. A 2D transthoracic echocardiogram was performed on all patients within 24 hours of diagnosis of PE. The severity of PE was based on the number of non-perfused pulmonary segments on lung scan or spiral CT. We excluded patients with severe COPD, shock/hypotension (SBP <100 mmHg) and/or chronic pulmonary hypertension. We collected data of history, symptoms, signs, laboratory, chest X-ray, ECG and echocardiographic findings. RVD diagnosis was made with echocardiography, in the presence of right/left ventricular end-diastolic diameter ratio > 0.7 in the parasternal long axis view without RV hypertrophy. We used the Student t test or Fisher's exact test to compare the two groups.

Results

Mean ages were 39 years (range 25–45 years) for younger and 81 years (range 70–93 years) for older adults. After comparison with older patients, younger patients had less typical PE risk factors (in particular recent immobilization: 20% vs 35%, P = 0.03; malignancy: 6% vs 36%, P < 0.001); less abnormal ECG: 40% vs 70%, P < 0.001 (right BBB was the more frequent abnormality in younger adults 30% vs 17%, P < 0.001); less abnormal X-ray (20% vs 40%, P < 0.001); lower D-dimer levels: mean of 875.8 μg/l vs 1889.7 μg/l in older adults (P < 0.05). Among younger adults, the more frequent symptoms were: dyspnoea (50%), chest pain (50% vs 30% in older, P = 0.006), cough (20% vs 5% in older, P = 0.003), hemoptysis (15% vs 5%, P < 0.03). At presentation, younger patients showed better parameters, better air room ABG (PaO₂, oxygen alveolar–arterial difference). Two groups had similar severity of PE: mean of non-perfused segments: 7.9 ± 3.1 standard deviation for younger patients vs 9.2 ± 5.9 standard deviation for older patients (P = 0.38). In two groups the number of patients with RVD was very similar: 32.5% in older adults vs 30% in younger (P > 0.05).

Discussion

Our study indicates that PE may present more subtly among younger patients. These results could be explained by the different pathophysiology and compensation of PE in younger patients. To our knowledge no one has compared the RVD in these two groups. Because of different pathophysiology and compensation of PE in these two groups, we were surprised to find a similar rate of RVD. Maybe the acute onset of PE does not allow compensation in both populations. The main limitations of the study were: few patients, incomplete data on etiology of PE in younger patients (few laboratory tests on thrombophilias), and the retrospective design of the study.

Conclusion

This study suggests one should be careful of insidious presentations of PE in younger patients and that RVD, a novel prognostic echocardiographic index, could be used in younger patients as in older patients.