Discrepancy between pulmonary arterial wedge pressure and left ventricular end diastolic pressure in patients with interstitial lung disease

Background

Right heart catheterization (RHC) is the gold standard for diagnosing pulmonary hypertension (PH) in patients with interstitial lung disease (ILD). However, discrepancies between pulmonary arterial wedge pressure (PAWP) and left ventricular end-diastolic pressure (LVEDP) remain understudied in this population.

Methods

We conducted a retrospective analysis of data from ILD patients who underwent RHC and had concomitant LVEDP measurements. Pulmonary vascular resistance (PVR) was calculated using both PAWP and LVEDP. Patients were categorized based on PAWP and LVEDP values using a threshold of 15 mm Hg and PVR values using a threshold of 2 or 3 Wood Units. After that patients were categorized as concordant or discordant if both values were on the same or opposite sides of these thresholds, respectively. A discordantly higher PAWP group (left atrial dysfunction, LAD) was defined as patients with a PAWP-LVEDP difference of more than 3 mm Hg.

Results

Among 87 ILD patients, 9 patients (10.3%) showed discordance between PAWP and LVEDP. LAD was observed in 12 patients (13.8%) and was associated with lower forced vital capacity (Odd ratio [OR]: 0.956, p = 0.049) and a larger left atrium diameter (OR: 3.205, p = 0.033). Discordance in PVR values was also noted, with potential treatment targets for PH-specific therapy differing in 9 patients (22.0%) depending on whether PAWP or LVEDP was used.

Conclusions

This study highlights the clinical significance of PAWP-LVEDP discrepancies in suspected PH-ILD patients, emphasizing the need for comprehensive assessments incorporating LVEDP and clinical context for accurate diagnosis, risk stratification, and treatment decisions.