title: Prognostic value of echocardiographic estimation of pulmonary vascular resistance in patients with acute pulmonary thromboembolism.
abstract: BACKGROUND
  Noninvasive calculation of pulmonary vascular resistance (PVR) has been reported to be feasible. We therefore evaluated whether baseline PVR could predict clinical outcomes in patients with acute pulmonary thromboembolism (aPTE).
  
  
  METHODS
  The study cohort consisted of 54 patients with aPTE who underwent both pretreatment and follow-up echocardiography. Doppler-derived PVR was calculated using the following equation: PVR (Woods unit [WU]) = (peak tricuspid regurgitant velocity [TRV(max)]/time-velocity integral of right ventricular outflow tract) × 10 + 0.16. Adverse clinical events included all-cause death and persistent pulmonary hypertension (TRV(max) >3.5 m/sec) on follow-up echocardiography.
  
  
  RESULTS
  During a clinical follow-up time of 2.4 ± 1.7 years, 16 patients experienced adverse events (death [n = 14]; persistent pulmonary hypertension [n = 8]). Patients who developed adverse events were significantly older than those who did not (68.0 ± 13.8 years vs 56.9 ± 15.4 years, P = .02) and showed higher initial PVR (4.5 ± 1.4 WU vs 3.5 ± 1.0 WU, P = .01) and TRV(max) (3.9 ± 0.6 m/sec vs 3.6 ± 0.5 m/sec, P = .02). The best cutoff value of PVR for predicting adverse events was 4.5 WU (area under the curve = 0.71, P = .02), with a sensitivity and specificity of 63% and 90%, respectively. PVR >4.5 WU (hazard ratio 5.68; 95% CI, 1.89-16.95; P = .002) and older age (hazard ratio per 10 years = 1.47; 95% CI, 1.02-2.12; P = .04) were independent factors associated with the development of adverse events. The 6-year overall survival (16% ± 14% vs 87% ± 6%, P < .0001) and event-free survival (15% ± 13% vs 84% ± 6%, P < .0001) rates differed according to initial PVR.
  
  
  CONCLUSIONS
  Echocardiographic estimation of PVR provides important prognostic information in patients with aPTE.
authors: Department of Cardiology, Asan Medical Center, University of Ulsan College of Medicine, 86 Asanbyeongwon-gil, Songpa-gu, Seoul, South Korea.
authors: Sung-Hwan
authors: SH
authors: Kim
authors: Myung-Zoon
authors: MZ
authors: Yi
authors: Dae-Hee
authors: DH
authors: Kim
authors: Jong-Min
authors: JM
authors: Song
authors: Duk-Hyun
authors: DH
authors: Kang
authors: Sang-Do
authors: SD
authors: Lee
authors: Jae-Kwan
authors: JK
authors: Song
mesh_terms: D000368:Aged; D019540:Area Under Curve; D015150:Echocardiography, Doppler / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D011655:Pulmonary Embolism / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012307:Risk Factors; D014655:Vascular Resistance