title: Preoperative partitioning of pulmonary vascular resistance correlates with early outcome after thromboendarterectomy for chronic thromboembolic pulmonary hypertension.
abstract: BACKGROUND
  Pulmonary thromboendarterectomy (PTE) is the preferred treatment for chronic thromboembolic pulmonary hypertension (CTEPH), but persistent pulmonary hypertension after PTE, as a result of either inaccessible distal thrombotic material or coexistent intrinsic small-vessel disease, remains a major determinant of poor outcome. Conventional preoperative evaluation is unreliable in identifying patients at risk for persistent pulmonary hypertension or predicting postoperative hemodynamic outcome. We postulated that pulmonary arterial occlusion pressure waveform analysis, a technique that has been used for partitioning pulmonary vascular resistance, might identify CTEPH patients with significant distal, small-vessel disease.
  
  
  RESULTS
  Twenty-six patients underwent preoperative right heart catheterization before PTE. Pulmonary artery occlusion waveform recordings were performed in triplicate. Postoperative hemodynamics after PTE were compared with preoperative partitioning of pulmonary vascular resistance derived from the occlusion data. Preoperative assessment of upstream resistance (Rup) correlated with both postoperative total pulmonary resistance index (R2=0.79, P<0.001) and postoperative mean pulmonary artery pressure (R2=0.75, P<0.001). All 4 postoperative deaths occurred in patients with a preoperative Rup <60%.
  
  
  CONCLUSIONS
  Pulmonary arterial occlusion pressure waveform analysis may identify CTEPH patients at risk for persistent pulmonary hypertension and poor outcome after PTE. Patients with CTEPH and Rup value <60% appear to be at highest risk.
authors.affiliation: University of California, San Diego, 9300 Campus Point Dr, M/C 7381, La Jolla, CA 92037-1300, USA.
authors.forename: Nick H S
authors.initials: NH
authors.lastname: Kim
authors.forename: Pierre
authors.initials: P
authors.lastname: Fesler
authors.forename: Richard N
authors.initials: RN
authors.lastname: Channick
authors.forename: Kirk U
authors.initials: KU
authors.lastname: Knowlton
authors.forename: Ori
authors.initials: O
authors.lastname: Ben-Yehuda
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Lee
authors.forename: Robert
authors.initials: R
authors.lastname: Naeije
authors.forename: Lewis J
authors.initials: LJ
authors.lastname: Rubin
mesh_terms: D000328:Adult; D000368:Aged; D002407:Catheterization, Swan-Ganz; D002908:Chronic Disease; D004691:Endarterectomy; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000401:mortality / Q000503:physiopathology* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011300:Preoperative Care; D011651:Pulmonary Artery / Q000503:physiopathology; D011655:Pulmonary Embolism / Q000150:complications / Q000601:surgery*; D011669:Pulmonary Wedge Pressure; D016896:Treatment Outcome; D014655:Vascular Resistance