Page 140 - Advanced echocardiography in characterization and management of patients with secondary mitral regurgitation

Chapter seven. Summary, conclusions and future perspectives
might be a better prognostic marker than LVEF and therefore could aid further risk stratification of patients with secondary MR.
Quantification of secondary MR remains challenging and its severity can be over- or underestimated. Chapter 4 evaluates the ratio of mitral regurgitant volume (RVol) and LV end-diastolic volume (LVEDV) and its association with prognosis. Patients with a RVol/EDV ratio <20%, defining a smaller RVol/larger EDV (i.e. more LV remodeling), had significantly higher mortality rates when compared to their counterparts. When considering patients receiving medical therapy only, patients with RVol/EDV ratio ≥20% tended to have higher mortality rates than those with RVol/EDV ratio <20%. Higher RVol/EDV ratio was independently associated with all-cause mortality. These results reflect the importance to take the relative severity of both MR and LV volume into account. RVol/EDV ratio may further improve risk stratification of patients with secondary MR and identify those who may benefit from transcatheter and surgical therapies to reduce severe secondary MR.
Chapter 5 examines the impact of MV geometry on outcomes after transcatheter edge- to-edge mitral valve repair with the MitraClip device (Abbott Vascular, Santa Clara, CA) compared to patients treated with guideline-directed medical therapy (GDMT). This present echocardiographic core laboratory study from the multicenter COAPT trial demonstrated that amongst many geometrical characteristics of the MV, a large anteroposterior mitral annular diameter and greater effective regurgitant orifice area (EROA) were the strongest echocardiographic predictors of HFH and death in patients treated with GDMT alone and with the MitraClip. A large anteroposterior mitral annular diameter was associated with increased risk of the composite outcome of all-cause death or HFH and HFH alone. Greater EROA was an independent predictor of mortality. Treatment with the MitraClip plus GDMT compared with GDMT alone reduced death and HFH consistently in patients with and without these extremes.
The chronic volume overload in patients with secondary MR eventually leads to pulmonary hypertension and right ventricular (RV) dysfunction with an increased risk of morbidity and mortality. In Chapter 6 we evaluated the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary arterial systolic pressure (PASP) as a non-invasively measure of RV to pulmonary artery (RV-PA) coupling (the relationship between RV contractility and afterload). A TAPSE/PASP ratio <0.35, defined as an impaired RV-PA coupling, was associated with an excess mortality. Patients with a TAPSE/PASP≥0.35 showed significantly better survival rates. TAPSE/PASP ratio also remained independently associated with all-cause mortality and showed to have an
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