Adjusting for esophageal pressure in obesity may lower pulmonary hypertension risk

Adjusting pulmonary hemodynamics for esophageal pressure in patients with obesity and high pulmonary artery wedge pressure reduced the risk for postcapillary pulmonary hypertension diagnosis, according to findings published in Chest.

“In a cohort of patients with obesity with pulmonary hypertension, we noted that using right heart catheterization measurements adjusted for esophageal pressure, which provides a true intravascular pressure, as opposed to traditional supine end-expiratory measurements, which are affected by extravascular factors, led to pronounced changes in pulmonary hypertension diagnosis and classification, including finding that about one-quarter of patients no longer fulfilled the criteria for pulmonary hypertension and a large decrease (from 94% to 19%) in the percentage of patients with postcapillary or combined precapillary and postcapillary pulmonary hypertension,” Ghaleb Khirfan, MD, pulmonary and critical care physician in the department of pulmonary and critical care medicine at Spectrum Health in Grand Rapids, Michigan, and colleagues wrote.

The prospective cohort study included 53 patients with obesity (mean age, 58.7 years; 66% women) who underwent right heart catheterization and had elevated pulmonary artery wedge pressure of at least 12 mm Hg. An esophageal balloon was placed, then researchers used air-filled transducers connected to regular hemodynamic monitors and measured pressure changes when sitting and variations during the respiratory cycle.

All patients had a mean pulmonary artery pressure of more than 20 mm Hg. and 50 patients had a pulmonary artery wedge pressure of more than 15 mm Hg with supine end-expiratory pressures.

Esophageal pressure adjustment resulted in a significant decrease in patients with postcapillary pulmonary hypertension, from 60% to 8%. In addition, this adjustment also led to a significant decrease in patients with combined precapillary and postcapillary pulmonary hypertension, from 34% to 11%, but an increase in patients with no pulmonary hypertension (0% to 23%), isolated precapillary pulmonary hypertension (2% to 25%) and undifferentiated pulmonary hypertension (4% to 34%).

According to the researchers, limitations of this study include its single-center design and inclusion of only patients with obesity, elevated mean pulmonary artery pressure and pulmonary artery wedge pressure.

“Adjusting pulmonary vascular pressures for esophageal pressure in patients with obesity with high pulmonary artery wedge pressure leads to pronounced changes in pulmonary hypertension diagnosis and classification and, given its relative simplicity, should be considered strongly in the appropriate setting,” the researchers wrote.