Pulmonary hypertension more common than thought after submassive PE
MedWire News: Signs or symptoms of pulmonary hypertension may be more common after submassive pulmonary embolism (PE) than previously thought, US researchers have found.
Studies examining the long-term consequences of submassive PE, defined as PE without echocardiographic evidence of right ventricular (RV) strain, have found that around 5% of patients develop chronic thromboembolic pulmonary hypertension (CTEPH) but patients may develop less serious symptoms, explain Jeffrey Kline (Carolinas Medical Center, Charlotte, North Carolina) and co-authors.
To improve understanding and guide submassive PE treatment, the team monitored the rate of pulmonary hypertension in 200 normotensive patients with a confirmed diagnosis of PE.
The patients’ right ventricular systolic pressure (RVSP) was estimated at diagnosis from an echocardiogram measurement of tricuspid regurgitation. The patients were treated with unfractionated heparin, with 21 receiving fibrinolysis for circulatory shock or respiratory failure. RVSP was repeated after 6 months in 162 patients, 18 of whom received dual therapy.
At baseline, pulmonary hypertension, defined as a RVSP of 40 mmHg or higher, was diagnosed in 50 (35%) of 144 patients treated with heparin only. This fell to just 10 (7%) of the patients after 6 months.
Just one patient was diagnosed with CTEPH, the team reports in the journal Chest.
However, RVSP had increased between diagnosis and follow-up in 39 (27%) of the 144 patients. Moreover, eighteen of these 39 patients had a follow-up New York Heart Association score of 3 or higher, or exercise intolerance, defined as a 6-minute walk distance of less than 330 m.
In patients given unfractionated heparin plus fibrinolysis, 11 (61%) of 18 patients had pulmonary hypertension at baseline, compared with just two (11%) at follow-up. None of the patients had an RVSP increase at follow-up.
“Our data imply that symptom-based, selective monitoring may be an insensitive screening measure for the identification of patients with tricuspid regurgitation suggestive of high right-side heart pressures,” Kline et al say.
But they note that “no current clinical guideline would trigger a change in treatment based on the discovery of an elevated RVSP in the absence of severe symptoms or coincident venous thromboembolism recurrence.”
Nevertheless, Kline et al conclude that “persistent or worsening tricuspid regurgitation suggestive of pulmonary hypertension occurs at a significant rate after acute submassive PE.”
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By Lynda Williams