Effects of prosthetic valve placement on mitral annular dynamics and the left ventricular base

Complications of transcatheter paravalvular leak device closure of mitral valve: An updated review of the literature and a rare case presentation

Paravalvular leak (PVL) is an uncommon complication of prosthetic valve implantation, which can lead to infective endocarditis, heart failure, and hemolytic anemia. Surgical reintervention of PVLs is associated with high mortality rates. Transcatheter PVL closure (TPVLc) has emerged as an alternative to surgical reoperation. This method provides a high success rate with a low rate of complications. This article reviews the pathogenesis, clinical manifestation, diagnosis, and management of PVL and complications following TPVLc. Besides, we presented a case of a patient with severe PVL following mitral valve replacement, who experienced complete heart block (CHB) during TPVLc. The first TPVLc procedure failed in our patient due to possible AV-node insult during catheterization. After 1 week of persistent CHB, a permanent pacemaker was implanted. The defect was successfully passed using the previous attempt. Considering the advantages of TPVLc, procedure failure should be regarded as a concern. TPVLc should be performed by experienced medical teams in carefully selected patients.

A comprehensive review of the diagnosis and management of mitral paravalvular leakage

Mitral paravalvular leaks (PVLs) commonly occur in patients with prosthetic valves. Paravalvular defects may be clinically inconsequential and may aggravate hemolysis or cause heart failure through regurgitation. Accordingly, patients may eventually require intervention such as redo surgery or a transcatheter closure of the defects. The introduction of purpose-specific closure devices and new steerable catheters has opened a new frontier for the transcatheter PVL closure. This mode of treatment is an initial therapy in most centers with experienced structural heart team. However, head-to-head data comparing two treatment modalities (surgery and transcatheter closure) are limited, and the world-wide experience is based on nonrandomized studies. Multimodality imaging, including three-dimensional transesophageal echocardiography, facilitates the delineation of mitral PVLs and provides essential data that aids the communication between the members of the structural heart team. In the near future, the success of interventional therapies will most probably increase in patients with mitral PVLs with the introduction of hybrid imaging modalities (echocardiography, cardiac computed tomography, and fluoroscopy). In conclusion, this paper summarizes the etiopathogenesis, clinical characteristics, diagnosis, and treatment of mitral PVLs. (Anatol J Cardiol 2020; 24: 350-60)

Long-term outcomes after reoperation for mitral paravalvular leaks: a single-centre experience

OBJECTIVES

We aimed to analyse the pathology of paravalvular leak (PVL), and determine the long-term outcomes of redo mitral valve replacement and risk factors of all-cause mortality.

METHODS

Seventy-nine patients (mean age 70 ± 9 years; 54 female, 68%) who underwent redo mitral valve replacement for mitral PVL between January 2000 and May 2019 were retrospectively reviewed. Indications for PVL intervention were haemolytic anaemia (57/79, 72%), New York Heart Association class III/IV congestive heart failure (56/79, 71%) and prosthetic valve endocarditis with PVL (2/79, 3%).

RESULTS

PVL most commonly occurred at lateral sectors (42/79, 55%). Early mortality occurred in 2 patients (3%) due to low cardiac output syndrome. Two patients (3%) had residual PVL at discharge. Sixteen patients (23%) developed late PVL (mean follow-up, 3.4 ± 2.9 years), among whom 11 (69%) developed PVL at same area as that preoperatively. Additionally, 9 patients (56%) developed PVL at lateral sectors in late follow-up. At 1, 5 and 10 years, the survival rate was 93%, 72% and 45%; rate of freedom from cardiac death was 96%, 92% and 78%; and rate of freedom from PVL recurrence was 94%, 82% and 54%, respectively. Chronic kidney disease was the only risk factor in the multivariate analysis for mortality [P = 0.013; hazard ratio 4.0 (1.4-11.0)].

CONCLUSIONS

Surgery for mitral PVL confers reasonable early and long-term outcomes. Greater attention to the anterolateral annulus may help prevent PVL.

Mitral annular hinge motion contribution to changes in mitral septal-lateral dimension and annular area

OBJECTIVE

The mitral annulus is a dynamic, saddle-shaped structure consisting of fibrous and muscular regions. Normal physiologic mechanisms of annular motion are incompletely understood, and more complete characterization is needed to provide rational basis for annuloplasty ring design and to enhance clinical outcomes.

METHODS

Seventeen sheep had radiopaque markers implanted; 16 around the annulus and 2 on middle anterior and posterior leaflet edges. Four-dimensional marker coordinates were acquired with biplanar videofluoroscopy at 60 Hz. Hinge angle was quantified between fibrous and muscular annular planes, with 0 degrees defined at end diastole, to characterize its contribution to alterations in mitral septal-lateral dimension and 2-dimensional total annular area throughout the cardiac cycle.

RESULTS

During isovolumic contraction (pre-ejection), hinge angle abruptly increased, reaching maximum (steepest saddle shape, change 18 degrees +/- 13 degrees ) at peak left ventricular pressure. During ejection, hinge angle did not change; it then decreased during early filling (change 2 degrees +/- 2 degrees ). Septal-lateral dimension and total area paralleled hinge angle dynamics and leaflet distance (anterior to posterior marker). Pre-ejection septal-lateral reduction was 13% +/- 7% (3.3 +/- 1.5 mm) from 9% muscular dimension fall and 18 degrees +/- 13 degrees hinge angle increase.

CONCLUSIONS

Pre-ejection increase in hinge angle contributes substantially to septal-lateral and total area reduction, facilitating leaflet coaptation. Semirigid annuloplasty rings or partial bands may preserve hinge motion, but possible recurrent annular dilatation could result in recurrent mitral regurgitation. Long-term clinical studies are required to determine who might benefit most from preserving intrinsic hinge motion without compromising repair durability.

Mitral valve periprosthetic leakage: anatomical observations in 135 patients from a multicentre study

OBJECTIVE

Prosthetic valve dysfunction after mitral valve replacement (MVR) may be caused by several factors, which often lead to repeated surgery. One of the most frequent determinants of reoperation is periprosthetic leakage (PPL). A few published reports have analysed PPL incidence and postoperative results after MVR, but no specific attention has been paid towards the potential relation between anatomical factors and PPL occurrence, particularly not bacterial-related. The aim of this study was to evaluate the location of PPL after MVR through a multicentre retrospective study.

METHODS

Between January 1985 and November 2005, 135 patients underwent reoperation at four institutions because of PPL after MVR and met the study inclusion criteria. The mitral valve annulus (MVA) was analysed in a clockwise format, indicating 12 o'clock as the mid-point of anterior annulus as viewed from the atrium.

RESULTS

Overall hospital mortality was 3.7% (five patients). Repair of PPL was carried out in 83 cases whereas prosthetic valve replacement was necessary in 52 cases. The total number of sectors involved in PPL was 244. PPL occurred more frequently between hour 5 and hour 6, and hour 10 and hour 11, with the risk of leakage being, 2.8 and 2.0 times higher, respectively, than in any other portion of the MVA.

CONCLUSIONS

Our study suggests that PPL occurs more frequently at antero-lateral and postero-medial segments of MVA. This finding might be linked to unusual anatomical and functional factors of the MVA and may call for adjunctive care to these sectors of MVA when performing suture placement during MVR.

Mitral annulus after mitral repair: geometry and dynamics

The study of systolic changes in both the inflow and outflow of the left ventricle after mitral repair elucidates the geometric characteristics after surgery. The study included eight normal subjects and six patients after mitral repair without a prosthesis. The left ventricular (LV) base, consisting of both mitral valve annulus (MVA) and left ventricular outflow tract (LVOT) orifice, was reconstructed from magnetic resonance images. The angle between the planes of the MVA and LV base (MB angle), and the proportionate share of the LVOT at the LV base were calculated. After mitral repair, both the MVA and LV base became almost normal in size, showing flexible change (i.e., contraction and dorsiflexion) in the MVA and contraction of the LV base in systole. Compared with the normal heart at 100 ms delay from the electrocardiogram R wave, the hearts of the patients at the same phase had a mean 1.05 cm2 larger LVOT orifice, resulting in a mean 8.0 degree larger MB angle. Furthermore, the LVOT orifice occupied a mean of 49.5% of the LV base (41.9% in normal subjects). We hypothesize that the higher MB angle at early systole may weaken the tension of the chordae of the anterior mitral leaflet.