Dynamic Risk Stratification of Patient Long-Term Outcome After Pulmonary Endarterectomy: Results From the United Kingdom National Cohort

Abstract

Background: Chronic thromboembolic pulmonary hypertension results from incomplete resolution of pulmonary emboli. Pulmonary endarterectomy (PEA) is potentially curative, but residual pulmonary hypertension following surgery is common and its impact on long-term outcome is poorly understood. We wanted to identify factors correlated with poor long-term outcome after surgery and specifically define clinically relevant residual pulmonary hypertension post-PEA.

Methods and results: Eight hundred eighty consecutive patients (mean age, 57 years) underwent PEA for chronic thromboembolic pulmonary hypertension. Patients routinely underwent detailed reassessment with right heart catheterization and noninvasive testing at 3 to 6 months and annually thereafter with discharge if they were clinically stable at 3 to 5 years and did not require pulmonary vasodilator therapy. Cox regressions were used for survival (time-to-event) analyses. Overall survival was 86%, 84%, 79%, and 72% at 1, 3, 5, and 10 years for the whole cohort and 91% and 90% at 1 and 3 years for the recent half of the cohort. The majority of patient deaths after the perioperative period were not attributable to right ventricular failure (chronic thromboembolic pulmonary hypertension). At reassessment, a mean pulmonary artery pressure of ≥30 mm Hg correlated with the initiation of pulmonary vasodilator therapy post-PEA. A mean pulmonary artery pressure of ≥38 mm Hg and pulmonary vascular resistance ≥425 dynes·s(-1)·cm(-5) at reassessment correlated with worse long-term survival.

Conclusions: Our data confirm excellent long-term survival and maintenance of good functional status post-PEA. Hemodynamic assessment 3 to 6 months and 12 months post-PEA allows stratification of patients at higher risk of dying of chronic thromboembolic pulmonary hypertension and identifies a level of residual pulmonary hypertension that may guide the long-term management of patients postsurgery.

Keywords: endarterectomy; hypertension, pulmonary; pulmonary embolism; survival.

Figure 1

Cumulative incidence (%) of pulmonary vasodilator therapy initiation after pulmonary endarterectomy. Number of patients at risk of treatment initiation over follow-up as shown. PEA indicates pulmonary endarterectomy.

Figure 2

Survival and classification of causes of death for PEA cohort. A, Kaplan–Meier curve showing cohort survival. B, Cumulative incidence of postoperative deaths improves with center experience. PEA number is consecutive PEA operations including indications other than CTEPH. N indicates number of PEA operations for CTEPH. C, Kaplan–Meier curve comparing survival of first versus second half of cohort. D, Cumulative incidence of causes of death (see Methods for classification) for patients surviving postoperative period. The number of patients at risk over follow-up as shown bottom of A and C. CTEPH indicates chronic thromboembolic pulmonary hypertension; and PEA, pulmonary endarterectomy.

Figure 3

Variables correlated with long-term mortality by univariable analyses. All continuous variables were standardized (see Table 2 legend). Red circles/bars define significant factors (P<0.05) and blue circles/bars define the nonsignificant factors. BMI indicates body mass index; COPD, chronic obstructive pulmonary disease; ECMO, extracorporeal membrane oxygenation; mPAP, mean pulmonary artery pressure PEA, pulmonary endarterectomy; PVR, pulmonary vascular resistance; and RAP, right atrial pressure.