Comparison of Right Ventricular Function Between Patients With and Without Pulmonary Hypertension Owing to Left-Sided Heart Disease: Assessment Based on Right Ventricular Pressure-Volume Curves.

ABSTRACT

OBJECTIVES: Right ventricular (RV) failure with pulmonary hypertension (PH) is frequently encountered in patients with advanced left-sided heart disease (LHD). However, RV energetics in patients with postcapillary PH because of LHD has not been well studied. The authors investigated intraoperative RV energetics in patients with PH due to LHD based on pressure-volume curves with three-dimensional transesophageal echocardiography and pulmonary artery catheterization. DESIGN: Exploratory study. SETTING: National center. PARTICIPANTS: Thirty-three patients who underwent cardiac surgery for LHD were enrolled. Ten patients had PH (mean pulmonary artery pressure ≥ 25 mmHg). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: RV stroke work index (RVSWI) was calculated by integrating the area bounded by the pressure-volume curve. RV minute work index (RVMWI) was calculated as RVSWI × heart rate. Right ventriculo-arterial coupling was estimated as stroke volume divided by end-systolic volume (SV/ESV). The authors compared RV energetics between patients with and without PH because of LHD. RVSWI and RVMWI were significantly higher in patients with PH (690.7 mmHg·mL/m2 [601.6-737.1] v 440.9 mmHg·mL/m2 [330.8-585.3], p = 0.015, and 60,068 mmHg·mL/m2/min [35,547-68,741] v 26,351 mmHg·mL/m2/min [17,316-32,517], p = 0.011, respectively), although cardiac index was nearly identical. SV/ESV was significantly lower in patients with PH (0.520 [0.305-0.810] v 0.820 (0.650-1.090), p = 0.007). CONCLUSIONS: Although cardiac index was similar, RVSWI and RVMWI were significantly higher and SV/ESV was significantly lower in patients with PH because of LHD, suggesting that patients with postcapillary PH have inefficient RV performance.