The Prevalence and Prognostic Implications of Elevated Pulmonary Vascular Resistance in Septic Patients.

Objective: Pulmonary vascular resistance (PVR) elevation is a critical factor contributing to acute right ventricular (RV) dysfunction. This study was designed to investigate the prevalence and prognostic significance of this condition in septic patients.

Design: An observational study.

Setting: A tertiary hospital intensive care unit.

Participants: A total of 638 septic patients.

Intervention: None.

Measurements and main results: Hemodynamic, echocardiographic, and prognostic data were collected. PVR was estimated using tricuspid regurgitation and RV outflow tract velocity-time integral. A PVR value exceeding 2.0 Wood units (WU) was considered abnormal. RV systolic dysfunction (RVSD) was determined by tricuspid annular plane systolic excursion, fractional area change, or RV S' velocity. Patients were categorized into four groups: (1) normal RV function (n = 205); (2) isolated RVSD (n = 76); (3) isolated PVR elevation (n = 195), and (4) RVSD + PVR elevation (n = 162). Cox regression analysis revealed that the presence of combined RVSD and PVR elevation was independently associated with 30-day mortality (hazard ratio [HR]: 2.907, 95% confidence interval [CI]: 1.385-6.100, p = 0.005). Conversely, neither isolated RVSD nor isolated PVR elevation was significantly associated with 30-day mortality (HR: 0.617, 95% CI: 0.168-2.274, p = 0.468; HR: 1.074, 95% CI: 0.469-2.461, p = 0.865, respectively). Subgroup analysis revealed that, compared with PVR ≤2.0 WU, PVR >2.0 WU was associated with 30-day mortality in patients with RVSD (HR: 3.878, 95% CI: 1.139-13.203, p = 0.030), but not in those with normal RV systolic function (HR: 1.632, 95% CI: 0.793-3.358, p = 0.183).

Conclusions: In septic patients, the combination of elevated PVR and RVSD was an independent predictor of 30-day mortality. However, neither PVR elevation nor RVSD alone was significantly associated with 30-day mortality. Further studies are warranted to elucidate the complex interplay between these factors in septic patients and explore potential therapeutic interventions.