Effect of advanced chronic kidney disease in clinical and echocardiographic outcomes of patients treated with MitraClip system

Implications of Renal Disease in Patients Undergoing Structural Interventions

Percutaneous structural interventions have a major impact on the morbidity, mortality, and quality of life of patients by providing a lower-risk alternative to cardiac surgery. However, renal disease has a significant impact on outcomes of these interventions. This review explores the incidence, outcomes, pathophysiology, and preventative measures of acute kidney injury and chronic kidney disease on transcatheter aortic valve replacement, transcatheter mitral valve repair, and percutaneous balloon mitral valvuloplasty. Given the expanding indications for percutaneous structural interventions, further research is needed to identify ideal patients with chronic kidney disease or end-stage renal disease who would benefit from intervention.

Transcatheter Mitral Valve Repair Technique in Specific Severe Mitral Regurgitation: Tips, Tricks, and Outcomes

Background

In specific patients with severe mitral regurgitation (MR), mitral valve (MV) pathology is unique and requires creative transcatheter repair techniques. This study aimed to evaluate the feasibility and safety of a new transcatheter MV repair technique, using occluder devices in symptomatic high-surgical-risk patients with severe MR, either due to MV leaflet (MVL) perforations or due to post-clips residual MR, and to report on their 6-month outcomes.

Methods

The study enrolled all high-risk patients with severe MR due to MVL perforations and post-clips residual MR who underwent transcatheter MV repair using occluder devices, from November 2016 to August 2019.

Results

The study enrolled 16 patients; 9 (56.25%) with MVL perforations and 7 (43.75%) with post-MitraClip (Abbott Laboratories, Abbott Park, Illinois) residual MR, with a mean age of 55.75 ± 16.69 years. Mean perforation/jet diameters were 5.75 ± 1.67 and 6.5 ± 1.93 mm, and the mean 3D-vena contracta area was 0.54 ± 0.14 cm². Perforations were crossed retrograde (transaortic in 7 [43.75%] patients and transapical in 2 [12.5%] patients), and post-MitraClip devices residual jets were crossed antegrade (transvenous/transseptal). Six (37.5%) patients required arteriovenous loop formation for device deployment, that was antegrade transvenous/transseptal in 13 (81.25%) patients and retrograde transapical in 3 (18.75%) patients. Devices used were Amplatzer-ASO in 10 (62.5%) patients and Amplatzer-VP-II in 6 (37.5%) patients. Mean procedural and fluoroscopy times were 55.13 ± 16.24 and 16.25 ± 4.03 ​minutes, respectively. Patients passed successfully, without MV gradient change or device-related complications.

Conclusions

Transcatheter MV repair of MVL perforations/post-clips residual MR is a new, feasible, and safe technique for high-surgical-risk patients.

Effect of Chronic Kidney Disease on 5-Year Outcome in Patients With Heart Failure and Secondary Mitral Regurgitation Undergoing Percutaneous MitraClip Insertion

Chronic kidney disease (CKD) is strongly related to outcomes in cardiovascular diseases. Limited data are available regarding the independent prognostic role of CKD after transcatheter mitral valve repair with MitraClip. We sought to evaluate the real impact of CKD in a large series of patients with heart failure (HF) and secondary mitral regurgitation (SMR) who underwent MitraClip treatment. The study included 565 patients with severe SMR from a multicenter international registry. Patients were stratified into 3 groups according to estimated glomerular filtration rate (eGFR) assessment before MitraClip implantation: normal eGFR (≥60 ml/min/1.73 m²) (n = 196), mild-to-moderate CKD (30 to 59 ml/min/1.73 m²) (n = 267), and severe CKD (<30 ml/min/1.73 m²) (n = 102). The primary end point was a composite of overall death and the first rehospitalization for HF, the secondary end points were overall death, cardiac death, and first rehospitalization for HF. CKD was present in about 2/3 of patients. At 5-year Kaplan-Meier analysis, primary clinical end point occurred in 60% of patients with normal eGFR, compared with 73% cases in patients with mild-to-moderate CKD and 91% in patients with severe CKD (p <0.001). Long-term overall death rate significantly decreased with increasing eGFR, and cardiac death and rehospitalization for HF rates. Multivariate Cox regression analysis identified severe CKD as the strongest independent predictor of adverse outcome (hazard ratio 2.136, 95% confidence interval 1.164 to 3.918, p = 0.014). In conclusion, CKD affected about 2/3 of patients who underwent MitraClip treatment for severe SMR, and it was a strong and independent predictor of 5-year adverse outcomes.

Valvular Heart Disease in Patients with Chronic Kidney Disease

Valvular heart disease (VHD) is highly prevalent in patients with chronic kidney disease (CKD) from the early stages to end-stage renal disease (ESRD). Aortic and mitral valves are the most frequently affected, leading to aortic valve and/or mitral annular calcification, which, in turn, causes either valve stenosis or regurgitation at an accelerated rate compared with the general population. Tricuspid regurgitation is also prevalent in CKD and ESRD, and haemodialysis patients are at an increasingly high risk of infective endocarditis. As for pathophysiology, several mechanisms causing VHD in CKD have been proposed, highlighting the complexity of the process. Echocardiography constitutes the gold standard for the assessment of VHD in CKD/ESRD patients, despite the progress of other imaging modalities. With regard to treatment, the existing 2017 European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines on the management of VHD addressing patients with normal kidney function are also applied to patients with CKD/ESRD.

Implications of Renal Disease in Patients Undergoing Structural Interventions

Chronic kidney disease patients have a high prevalence of severe valvular heart disease, which reduces life expectancy. Transcatheter valve interventions has revamped the way we manage severe valvular heart disease and are an attractive alternative to invasive surgery in patients with chronic kidney disease and severe valvular heart disease. This review summarizes the impact of transcatheter valve interventions in patients with severe valvular heart disease and chronic kidney disease.

Interrelationship Between Kidney Function and Percutaneous Mitral Valve Interventions: A Comprehensive Review

Percutaneous mitral valve repair is emerging as a reasonable alternative especially in those with an unfavorable surgical risk profile in the repair of mitral regurgitation. At this time, our understanding of the effects of underlying renal dysfunction on outcomes with percutaneous mitral valve repair and the effects of this procedure itself on renal function is evolving, as more data emerges in this field. The current evidence suggests that the correction of mitral regurgitation via percutaneous mitral valve repair is associated with some degree of improvement in cardiac function, hemodynamics and renal function. The improvement in renal function was more significant for those with greater renal dysfunction at baseline. The presence of Chronic Kidney Disease (CKD) in turn has been associated with poor long-term outcomes including increased mortality and hospitalization among patients who undergo percutaneous mitral valve repair. This was true regardless of the degree of improvement in GFR post repair advanced CKD. The adverse impact of CKD on long-term outcomes was consistent across all studies and was more prominent in those with GFR<30 mL/min/1.73 m². It is clear that from these contrasting evidences of improved renal function post mitral valve repair but poor long-term outcomes including increased mortality in patients with CKD, that proper patient selection for percutaneous mitral valve repair is key. There is a need to have better-standardized criteria for patients who should qualify to have percutaneous mitral valve replacement with Mitraclip. In this new era of percutaneous mitral valve repair, much work needs to be done to optimize long-term patient outcomes.

Comparison of Transcatheter Mitral Valve Repair Versus Surgical Mitral Valve Repair in Patients With Advanced Kidney Disease (from the National Inpatient Sample)

Transcatheter mitral valve repair (TMVR) is an emerging treatment modality that has been reserved for high-risk patients with multiple co-morbidities. We hypothesize that TMVR is a safe and effective procedure for patients with moderate to severe mitral regurgitation who are not surgical candidates. The National Inpatient Sample (2012 to 2014) using the International Classification of Diseases, 9th Revision, Clinical Modification procedure codes 35.97 for TMVR and 35.12 for surgical mitral valve repair (SMVR) were used. Patients with chronic kidney disease stage IV, Stage V, and end-stage renal disease (ESRD) were considered as patients with advanced kidney disease. A total of 2,123 patients were treated with SMVR and 74 patients were treated with TMVR. There were notably fewer patients treated with TMVR compared with patients treated with SMVR. The mean age was higher with the TMVR group (72.4 vs 61.7 years, p = <0.001). After performing multivariate regression analysis, the primary outcome of in-hospital mortality (13.8% vs 1.3%, adjusted p = 0.003) and all secondary outcomes, excluding dialysis requirement, cardiogenic shock, and cardiac arrest, were significantly lower with the TMVR approach. The average length of stay was lower with TMVR compared with SMVR (22.8 vs 12.6 days, adjusted p = <0.001), with reduced in-hospital costs ($98,165 vs $52,646, adjusted p = <0.001). This large, national study suggests TMVR is associated with significantly lower in-patient morbidity and mortality, with significant cost savings in patients with advanced kidney disease compared with SMVR. Hence, TMVR could be a safe and effective alternative for patients with advanced kidney disease who are not surgical candidates.

Established interventions for mitral valve regurgitation. Current evidence

Severe mitral regurgitation (MR) is a growing medical challenge in today's aging population, leading to increased health expenditure due to the resultant morbidity and mortality. Surgery, either replacement or repair, has been the mainstay of therapy for primary MR. In high-risk or inoperable patients, treatment was limited to medical therapy until 2008. Since then, alternative percutaneous therapies have been introduced and have proven to be safe and effective in patients with secondary MR. Edge-to-edge repair with the MitraClip system is applied worldwide for primary and secondary MR. Randomized data do not support its application in low-risk patients with primary MR. Results from ongoing and future randomized trials will clarify its impact on important clinical endpoints in high-risk and inoperable patients. The Carillon device is a percutaneous indirect annuloplasty technique introduced in 2009 for secondary MR. Clinical data for the novel Cardioband system, using a different intra-atrial annuloplasty technique, have been gathered from more than 40 patients and the system recently received CE mark approval. Other percutaneous repair devices and implantable valves are under development and may be introduced into clinical practice soon. The percutaneous interventional therapy of MR is a highly dynamic field of cardiovascular medicine and has the potential to improve quality of life as well as morbidity and mortality in selected patients.

Impact of residual mitral regurgitation after MitraClip implantation

BACKGROUND

MitraClip (MC) is an alternative treatment for mitral regurgitation (MR). Although residual MR is common after MC, little was known about the impact of residual MR after MC.

METHODS

We examined 255 consecutive patients who underwent MC. The primary endpoint was the composite endpoint including all-cause death, left ventricular (LV) assist device, and mitral valve surgery.

RESULTS

Procedure failure defined as unsuccessful MC implantation (n=6) and residual MR ≥3+ (n=19) was associated with worse outcomes including the primary endpoint and all-cause death than those with acute procedure success (APS) defined as residual MR 2+ (n=125) or 1+ (n=105). Among patient with APS, background characteristics including age, MR etiology, heart failure severity, and LV function were not different. Although MR grade and NT-pro BNP level at 6months after MC were higher in patients with residual MR 2+, there was no significant difference in the incidence of the primary endpoint and all-cause death. Subanalysis showed that the primary endpoint occurred more frequently in patients with MR 2+ in patients with LV ejection fraction ≤40%, chronic kidney disease, and baseline NYHA-class IV.

CONCLUSION

Procedure failure was associated with adverse outcomes after MC. Among patients with APS, residual MR 2+ was not significantly associated with overall worse outcomes than residual MR 1+. However, residual MR 2+ was associated with poorer prognosis in patients with impaired LV function, renal dysfunction, and severe heart failure, suggesting that the optimal endpoint of MC procedure should be individualized according to each patient's baseline characteristic.

Managing mitral regurgitation: focus on the MitraClip device

Based on the principle of surgical edge-to-edge mitral valve repair (MVR), the MitraClip percutaneous MVR technique has emerged as a minimally invasive option for MVR. This catheter-based system has been widely demonstrated to be safe, although inferior to surgical MVR. Studies examining patients with ≥3+ mitral regurgitation (MR) show that, for all patients treated, freedom from death, surgery, or MR ≥3+ is in the 75%–80% range 1 year following MitraClip implantation. Despite its inferiority to surgical therapy, in high-risk surgical patients, data suggest that the MitraClip system can be employed safely and that it can result in symptomatic improvement in the majority of patients, while not precluding future surgical options. MitraClip therapy also appears to reduce heart failure readmissions in the high-risk cohort, which may lead to an economic benefit. Ongoing study is needed to clarify the impact of percutaneous mitral valve clipping on long-term survival in high-risk populations, as well as its role in other patient populations, such as those with functional MR.

Novel therapeutic strategies for Alzheimer's disease based on the forgotten reproductive hormones

The relationship between hormones and Alzheimer's disease (AD) has been intensely researched. While the majority of this work has focused on the sex steroids, estrogens, and more recently androgens, a serendipitous patient encounter led one of us (R.L.B.) to question whether other hormones of the hypothalamic-pituitary-gonadal axis might play a role in the pathogenesis of AD. The age-related decline in reproductive function results in a dramatic decrease in serum estrogen and testosterone concentrations and an equally dramatic compensatory increase in serum gonadotropin concentrations. Indeed, there is growing evidence that the gonadotropin luteinizing hormone, which regulates serum estrogen and testosterone concentrations, is an important causative factor in the development of AD. This review provides information supporting the 'gonadotropin hypothesis'. We put forth a novel mechanism of how changes in serum luteinizing hormone concentrations could contribute to the pathogenesis of AD and discusses potential therapeutic anti-gonadotropin compounds.