Predictors of persistence of functional mitral regurgitation after cardiac resynchronization therapy:Review of literature

Functional mitral regurgitation is a common finding among heart failure patients with ischemic and non-ischemic dilated cardiomyopathies.The presence of moderate or severe mitral regurgitation is associated with higher morbidity and mortality.Heart failure patients meeting electrocardiogram and left ventricle function criteria are good candidates for cardiac resynchronization therapy,which may reduce the degree of functional mitral regurgitation in the short and long term,specifically targeting myocardial dyssynchrony and inducing left ventricle reverse remodeling.In this article,we analyze data from the literature about predictors of mitral regurgitation improvement after cardiac resynchronization therapy implantation.

Mitral valve cleft gapping mechanism in functional mitral regurgitation:An in-vitro study

Background and aim:Gapping formation of the mitral valve cleft is unknown.The objective of this study was to quantify the geometry of mitral valve cleft coaptation in the asymmetric and symmetric papillary muscles(PMs)positions in a dilated annulus in order to reveal mitral valve gapping mechanism.Methods:Nine fresh porcine mitral valves with the posterior leaflet clefts were sutured onto a saddle-shaped dilated annulus in an in-vitro experiment to simulate mitral valve closure at hydrostatic pressure.PMs were adjusted to the normal position,and subsequently to positions of asymmetric and symmetric PM displacement.Sonomicrometry was used to measure positions of the lateral and medial clefts.Results:PM displacement tethered the leaflets.Both the opening angle and contact angle of the lateral cleft,but not of the medial cleft,increased in the asymmetric PM displacement.Neither the opening angle nor contact angle of both clefts increased in the symmetric PM displacement.Conclusions:Displacement of the postero-medial PM moves the posterior leaflet medially and impairs coaptation of the lateral cleft,but not medial cleft,which suggest that the medial cleft displacement in the asymmetric PM position is another mechanism of gap formation in addition to leaflet tenting due to apical leaflet displacement.Symmetric PM displacement cause leaflet tenting,but doesn’t impair the leaflet cleft coaptation,which suggest that the asymmetric PM position is even worse than the symmetric PM position.

Functional mitral regurgitation combined with increased early diastolic transmitral velocity to early mitral annulus diastolic velocity ratio is associated with a poor prognosis in patients with shock

Background:Functional mitral regurgitation(FMR)is common in critically ill patients and may cause left atrial(LA)pressure elevation.This study aims to explore the prognostic impact of synergistic LA pressure elevation and FMR in patients with shock.Methods:We retrospectively screened 130 consecutive patients of 175 patients with shock from April 2016 to June 2017.The incidence and impact of FMR and early diastolic transmitral velocity to early mitral annulus diastolic velocity ratio(E/e’)≥4 within 6 h of shock on the prognosis of patients were evaluated.Finally,the synergistic effect of FMR and E/e’were assessed by combination,grouping,and trend analyses.Results:Forty-four patients(33.8%)had FMR,and 15 patients(11.5%)had E/e’elevation.A multivariate analysis revealed FMR and E/e’as independent correlated factors for 28-day mortality(P=0.043 and 0.028,respectively).The Kaplan-Meier survival analysis revealed a significant difference in survival between patients with and without FMR(χ2=7.672,P=0.006)and between the E/e’≥14 and E/e’<14 groups(χ2=19.351,P<0.010).Twenty-eight-day mortality was significantly different among the four groups(χ2=30.141,P<0.010).The risk of 28-day mortality was significantly higher in group 4(E/e’≥14 with FMR)compared with groups 1(E/e’<14 without FMR)and 2(E/e’<14 with FMR)(P=0.001 and 0.046,respectively).Conclusions:Patients with shock can be identified by the presence of FMR.FMR and E/e’are independent risk factors for a poor prognosis in these patients,and prognosis is worst when FMR and E/e’≥14 are present.It may be possible to improve prognosis by reducing LA pressure and E/e’.Trial Registration:ClinicalTrials.gov,NCT03082326.