Symptoms Are More Useful Than Echocardiography in Patient Selection for Pulmonary Endarterectomy

Chronic thromboembolic pulmonary hypertension (CTEPH) is still largely underdiagnosed in the general population. Although transthoracic echocardiogram (TTE) is recommended to screen for CTEPH, it may not detect patients with chronic thromboembolic disease (CTED) and mild or exercise-induced pulmonary hypertension (PH) who could also benefit from pulmonary endarterectomy (PEA).

All patients referred to our CTEPH program with persistent mismatched perfusion defects on ventilation-perfusion (VQ) scan between January 2005 and June 2015 were divided into three groups according to TTE and right heart catheterization (RHC) as follows: (1) typical CTEPH group (PH on RHC and TTE), (2) TTE-negative (neg) CTEPH group (PH on RHC, but not TTE), or (3) CTED group (no PH on RHC and TTE).

Of 225 patients with abnormal VQ scans, 188 (84%) had typical CTEPH, 15 had TTE-neg CTEPH, and 22 had CTED. PEA was performed in 179 patients (80%). Reasons for exclusion in CTEPH patients included primarily distal disease (n = 11) and comorbidities (n = 10). In contrast, the absence of functional limitation was the main cause of exclusion in CTED patients (75% versus 3% in CTEPH patients, p < 0.0001). The 90-day mortality rate after PEA was 4% in the typical CTEPH group and 0% in the TTE-neg CTEPH and CTED groups. Pulmonary arterial pressures and functional class significantly improved after PEA in all three groups.

Patients with mild CTEPH can benefit from PEA, but may not be detected by TTE. Symptomatic patients with functional limitation and persistent mismatched perfusion defects on VQ scan should undergo further investigations with pulmonary angiogram and RHC.