Pulmonary hypertension due to left heart disease: The prognostic implications of diastolic pulmonary vascular pressure gradient.

Background: Compared to transpulmonary pressure gradient (TPPG), diastolic pulmonary vascular pressure gradient (DPG) may be a more sensitive and specific indicator for pulmonary hypertension (PH) due to left heart disease (LHD) with significant pulmonary vascular disease (PVD). The aim of this study was to investigate the incidence and clinical features of PH-LHD with PVD classified by DPG and TPPG.

Methods: We analyzed 410 patients admitted for symptomatic heart failure (HF) (New York Heart Association ≥2) and who underwent right heart catheterization (RHC) at compensated stage between 2007 and 2012. Patients with PH-LHD were divided into 3 groups according to the value of DPG and TPPG (Non-PVD group: DPG <7mmHg and TPPG ≤12mmHg; TPPG-PVD group: DPG <7mmHg and TPPG >12mmHg; DPG-PVD group: DPG ≥7mmHg). Multivariate Cox regression analysis was applied to investigate whether each PH-LHD category predicts death or HF readmission after adjusting for other variables.

Results: PH-LHD was observed in 164 patients (40%) with symptomatic HF. Thirteen patients (3%) were allocated into DPG-PVD group, while 24 patients were allocated into TPPG-PVD group (6%). DPG-PVD group was significantly associated with death or HF readmission compared to non-PVD group (hazard ratio: 3.57; 95% CI: 1.33 to 9.55, p=0.01), while the association between TPPG-PVD group and non-PVD group did not reach statistical significance (hazard ratio: 1.89; 95% CI: 0.77 to 4.64, p=0.17).

Conclusions: PH-LHD with PVD classified by DPG was significantly associated with poor long-term clinical outcomes, whereas the association between PH-LHD with PVD classified by TPPG and clinical outcomes did not reach statistical significance. However, further studies are needed, because there was no substantial difference in clinical outcomes between PH-LHD with PVD classified by DPG and PH-LHD with PVD classified by TPPG.