PURPOSE: Little is known regarding the rate of resolution of pulmonary thrombi after diagnosis of pulmonary embolism (PE). Up to 4% of first-time PE patients may acquire chronic thromboembolic pulmonary hypertension. We examined how often follow-up ventilation-perfusion (V/Q) scan was performed in daily clinical practice and which factors could predict clot resolution.
METHODS: All files of patients presenting with symptoms of acute PE and high probability V/Q scan admitted between 2003-2006 were reviewed. D-dimer level and echocardiographic estimation of the mean systolic pulmonary artery pressure (sPAP)assessed in the acute phase of their PE are compared between those patients with persistend V/Q mismatch and those with normalised V/Q scan after PE treatment.
RESULTS: 144 patients with PE and high-probability V/Q scan were admitted during the observation interval.In 32/144 (22%)a follow-up scan was performed(23 woman and 9 men, mean age 72.9 years(SD±13.4 y). Mean interval between scans was 172 days (SD±181 days).Residual defects were observed in 11/32(34%) of patients.6/11 (54%) had idiopathic PE compared to 12/21(57%) of the patients with complete clot resolution (NS). Mean sPAP was 45.7 mmHg (SD±7.8)in the patients with persistent perfusion defects compared to 35.5 mmHg (SD±15.4)in the group without persfusion defects (p= 0.34).Acute D-dimer level was 4111 ng/dL (SD±3017) in the group with perfusion defects after treatment compared to 4342 ng/dL(SD±3469) in the patients with normalised V/Q scan.
CONCLUSION: Although this is a retrospective analysis with inherent selection bias, incomplete recovery of lung perfusion is observed in at least one third of correctly treated PE patients. Neither baseline mean sPAP nor D-dimer level seem to predict who is at risk for persistent perfusion defects.
CLINICAL IMPLICATIONS: These results emphasize the need for more systematic control V/Q scanning at completion of anticoagulation therapy for PE.
DISCLOSURE: Marc Meysman, No Financial Disclosure Information; No Product/Research Disclosure Information