Right Ventricle-Pulmonary Artery Coupling and Major Morbidity and Operative Mortality After Cardiac Surgery

Area of Science:

• Cardiology
• Cardiac Surgery
• Pulmonary Hypertension

Background:

• The right ventricle-pulmonary artery (RV-PA) coupling ratio assesses right ventricular (RV) function relative to pulmonary artery (PA) afterload.
• A diminished preoperative RV-PA ratio correlates with higher mortality post-transcatheter procedures.
• This study investigates the association between a low preoperative RV-PA ratio and major morbidity and operative mortality (MMOM) in cardiac surgery patients.

Purpose of the Study:

• To determine if a lower preoperative RV-PA ratio independently predicts an increased risk of MMOM in patients undergoing cardiac surgery.
• To explore the relationship between the RV-PA ratio and other postoperative outcomes, including length of stay and mechanical ventilation duration.

Main Methods:

• A retrospective cohort study included 868 adult patients undergoing coronary artery bypass graft and/or valve surgery.
• The RV-PA ratio was calculated as the ratio of tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PASP).
• Multivariable analysis assessed the association of the TAPSE/PASP ratio with MMOM (defined by STS criteria) and secondary outcomes, with a P-value <0.05 indicating statistical significance.

Main Results:

• Of 868 patients, 14.3% experienced MMOM. Patients with a low TAPSE/PASP ratio had significantly higher rates of MMOM (22.0% vs 7.4%, P < .001).
• Low TAPSE/PASP ratio was associated with longer intensive care unit length of stay (ICU-LOS), hospital length of stay (H-LOS), and mechanical ventilation time (MVT).
• Multivariable analysis revealed that a TAPSE/PASP ratio <0.52 mm/mm Hg significantly increased MMOM risk (OR 1.77, 95% CI 1.10-2.83, P = .018). Each 0.1 mm/mm Hg increase in ratio reduced ICU-LOS and MVT by 4%, and H-LOS by 3%.

Conclusions:

• A preoperative TAPSE/PASP ratio below 0.52 mm/mm Hg is a significant independent predictor of increased MMOM risk in cardiac surgery patients.
• Lower preoperative RV-PA ratios are associated with prolonged ICU-LOS, H-LOS, and MVT, even after adjusting for STS risk score and cardiopulmonary bypass time.