TAPSE/PAPS ratio as a predictor of hospital staying in patients affected by severe degenerative mitral regurgitation undergoing mitral valve surgery

Funding Acknowledgements Type of funding sources: None. Background Chronic severe degenerative mitral regurgitation (DMR) is a progressive disease with a negative impact on prognosis and surgical repair or replacement represents the standard of care. Recently, the coupling between right ventricular (RV) function and the pulmonary circulation (Pc) emerged as a prognostic index in patients undergoing transcatheter edge-to-edge mitral repair. However, the relationship between pulmonary circulatory right ventricular uncoupling and clinical outcomes in patients undergoing surgery for DMR has poorly been investigated. Purpose In a cohort of patients affected by DMR undergoing mitral valve surgery (repair or replacement), we investigated the association between the degree of RV-to-Pc uncoupling, assessed by the ratio between tricuspid annular plane systolic excursion (TAPSE) to pulmonary artery systolic pressure (PAPS), and the time of hospitalization. Methods 389 consecutive patients affected by DMR who underwent mitral surgery (repair or replacement) were retrospectively enrolled. In the pre-operatory phase, all patients underwent a transthoracic echocardiography. The degree of RV-to-PC uncoupling was defined by TAPSE/PASP ratio with a cut-off of 0.4 mm/mmHg and was correlated with the time of hospitalization expressed in days. Results A total of 389 eligible patients (mean age 52±14 y, 65% male, 85% in sinus rhythm) who were admitted for mitral valve surgery at San Raffaele hospital (85% repair, 15% replacement) for hemodynamically significant DMR were retrospectively enrolled from January 2019 to June 2022. Mean hospital stay was 11±8 days. At baseline, only 28% of the cohort exhibited normal left ventricular (LV) and left atrial (LA) size and function, with the majority of the cohort exhibiting increased LA dimension (mean LAVi 49±10 ml/m2). RV to PC coupling was measured before surgery (mean TAPSE/PAPS: 0.8±0.2 mm/mmHg) and only 15% of the cohort had a TAPSE/PAPS≤0.4 mm/mmHg. Interestingly, patients with lower TAPSE/PAPS ratio had longer hospitalization (TAPSE/PAPS≤0.4 mm/mmHg: 15±8.2 days vs TAPSE/PAPS >0.4 mm/mmHg: 11±7.5 days; p = 0.04) and an inverse relationship was found between TAPSE/PAPS values at admission and the length of hospitalization (r=0.4, CI 95% 0.21–0.57; p<0.001; Figure 1). Conclusions In DMR, a strong association was noted between TAPSE/PAPS ratio and length of hospitalization in patients undergoing mitral valve surgery. These data, although preliminary, underline the impact of RV dysfunction and PC uncoupling on clinical outcomes also in the short-term evolution after surgery.