Acute and Midterm Outcome After MitraClip Therapy in Patients With Severe Mitral Regurgitation and Left Ventricular Dysfunction

In-hospital complications after MitraClip in patients with heart failure and preserved versus reduced ejection fraction in the United States

BACKGROUND

The clinical benefits of transcatheter edge to edge mitral valve repair have been well established in patients with heart failure and severe mitral regurgitation (MR) who have prohibitive surgical risk. In March of 2019, the FDA approved the MitraClip for treatment of selected patients with HF and severe secondary MR. However, the relative outcomes of patients with HFrEF and HFpEF treated with MitraClip are largely unknown. We therefore sought to investigate the incidence and characteristics of in-hospital mortality in patients with HFpEF and HFrEF following MitraClip.

METHODS

The study sample analyzed was originated from the National Inpatient Sample (NIS) registry which includes data from hospitalized patients in the United States (US) between January 1, 2012 and December 31, 2020. Data were extracted from the entire NIS registry using ICD-9 codes. Patients with the primary or secondary diagnosis of MitraClip were identified. Hospitalizations for HFpEF and HFrEF were identified based on ICD-9-CM and ICD-10-CM codes. Demographics, conventional risk factors, and in-hospital outcomes were evaluated.

RESULTS

23,260 hospitalizations for MitraClip implantation between 2016 and 2020 were analyzed. The HFrEF group had higher absolute rates of complications as well as a higher observed in-hospital mortality (2.4 % vs 1.7 %; OR 0.75 95 % CI 0.44-1.26; p 0.28) which did not meet statistical significance. Absolute rates of acute myocardial infarction (AMI), acute kidney injury (AKI) and respiratory failure necessitating invasive mechanical ventilation were observed to be higher among HFrEF patients. Post-procedural shock was significantly more common in patients with HFrEF (9.0 % vs 2.8 %: OR 0.34 95 % CI 0.25-0.48 p < 0.001). Significantly longer hospitalizations were observed in the HFrEF cohort (5.3 ± 11.2 days vs 4.2 ± 7.3 days; p < 0.001) as well as a higher total hospitalization cost (61,723 ± 56,728 USD vs 57,278 ± 46,143).

CONCLUSIONS

In the present study of US patients, those with HFrEF were observed to have statistically higher risk of in-hospital post-procedural shock and longer hospitalization length of stay when compared with patients with HFpEF who underwent MitraClip implantation. Additionally, patients with HFrEF undergoing MitraClip procedure were observed to have higher absolute rates of certain post-procedural complications, however these observations did not reach statistical significance. Understanding of the aforementioned differences after MitraClip implantation may be useful in-patient selection, prognostic guidance, and hypothesis generation to propel future large clinical studies.

Percutaneous Mitral Valve Intervention Using MitraClip for Functional Mitral Regurgitation and Heart Failure

Functional mitral regurgitation (FMR) frequently coexists with left ventricular systolic dysfunction and advanced heart failure, and typically has poor clinical outcomes. Although various therapeutic options including cardiac resynchronization therapy and surgical mitral intervention, have been proposed, an optimal treatment strategy for functional mitral regurgitation has not yet been established. Over the last decade, transcatheter mitral valve repair using MitraClip has emerged as a novel alternative therapeutic option for functional mitral regurgitation. In 2018, the COAPT trial demonstrated that MitraClip treatment reduced rehospitalization due to heart failure and all-cause death in patients with functional mitral regurgitation and heart failure. As a consequence, the MitraClip has become a very promising potential treatment for functional mitral regurgitation. In this review, we discuss and summarize the current status and future perspectives of the treatment for functional mitral regurgitation and heart failure.

"Get with the Guidelines Heart Failure Risk Score" for mortality prediction in patients undergoing MitraClip

BACKGROUND

Reliable risk scores in patients undergoing transcatheter edge-to-edge mitral valve repair (TMVR) are lacking. Heart failure is common in these patients, and risk scores derived from heart failure populations might help stratify TMVR patients.

METHODS

Consecutive patients from three Heart Centers undergoing TMVR were enrolled to investigate the association of the "Get with the Guidelines Heart Failure Risk Score" (comprising the variables systolic blood pressure, urea nitrogen, blood sodium, age, heart rate, race, history of chronic obstructive lung disease) with all-cause mortality.

RESULTS

Among 815 patients with available data 177 patients died during a median follow-up time of 365 days. Estimated 1-year mortality by quartiles of the score (0-37; 38-42, 43-46 and more than 46 points) was 6%, 10%, 23% and 30%, respectively (p < 0.001), with good concordance between observed and predicted mortality rates (goodness of fit test p = 0.46). Every increase of one score point was associated with a 9% increase in the hazard of mortality (95% CI 1.06-1.11%, p < 0.001). The score was associated with long-term mortality independently of left ventricular ejection fraction, NYHA class and NTproBNP, and was equally predictive in primary and secondary mitral regurgitation.

CONCLUSION

The "Get with the Guidelines Heart Failure Risk Score" showed a strong association with mortality in patients undergoing TMVR with additive information beyond traditional risk factors. Given the routinely available variables included in this score, application is easy and broadly possible.

MitraClip in Patients With Mitral Regurgitation and Left Ventricular Ejection Fraction <30% - Potential Implications for the Treatment of Patients in Japan

BACKGROUND

The effect of the unique Japanese indication for MitraClip based on left ventricular ejection fraction (LVEF) is unclear.

METHODS AND RESULTS

We analyzed 874 patients who underwent MitraClip because of mitral regurgitation (MR) and compared the characteristics and outcomes between patients with LVEF <30% and ≥30%. Patients with LVEF ≤30% accounted for 33% of the study population and had a higher prevalence of functional MR. Severity of MR after MitraClip was comparable, and LVEF <30% did not independently affect survival.

CONCLUSIONS

Japanese unique indication based on LVEF may exclude one third of patients who were treated with MitraClip in Europe.

Transcatheter Mitral Valve Therapy: Defining the Patient Who Will Benefit

PURPOSE OF REVIEW

This report aims to define the clinical and anatomic variables key in determining patient suitability for transcatheter mitral valve therapies.

RECENT FINDINGS

Candidacy for transcatheter mitral valve repair requires weighing the clinical variables that may impact the ability to improve patient symptoms and prolong survival that include left ventricular ejection fraction, symptom severity, pulmonary hypertension, and magnitude of residual regurgitation or stenosis. Individualized selection of transcatheter repair or replacement based on patho-anatomy is being explored. The primary goal is achieving significant reduction in mitral regurgitation. Transcatheter mitral valve replacement requires rigorous anatomic screening using computed tomography and candidates should be able to take oral anticoagulation. Selection of patients for transcatheter mitral valve repair is complex and requires intimate knowledge of clinical variables and specific device limitations.

Acute Hypotension After MitraClip Implantation due to Acute Left Ventricular Failure

The MitraClip is a percutaneously implanted device approved for the treatment of symptomatic organic mitral regurgitation in poor surgical candidates. Despite its proven efficacy and safety for mitral regurgitation treatment, the MitraClip may unmask the true afterload of the left ventricle by removing the low-pressure left atrial system and may cause acute left ventricular systolic failure (afterload mismatch). Rapid diagnosis and treatment of afterload mismatch is crucial to ensure optimal patient outcomes. The authors present a case of acute hemodynamic deterioration after MitraClip implantation in a patient with chronic severe left ventricular systolic dysfunction. Transesophageal echocardiography was pivotal for the rapid recognition of acute left ventricular failure and aided in the intraoperative decision-making process and therapy.

Interventional Therapies for Heart Failure in Older Adults

Heart failure (HF) remains the leading cause of hospitalization in older adults and is associated with increased morbidity and mortality despite the use of guideline-directed medical therapy. There has been tremendous progress in the development of novel transcatheter and interventional therapies for HF over the past decade. The evolution of structural heart disease interventions and interventional HF has led to a multidisciplinary heart team approach in the management of HF patients. Careful selection of the appropriate patient population and end points in future randomized controlled trials will be crucial to demonstrate the potential efficacy of the novel interventional HF therapies.

Safety and efficacy of MitraClip™ therapy in patients with severely impaired left ventricular ejection fraction: results from the German transcatheter mitral valve interventions (TRAMI) registry

AIMS

The aim of the present study was to assess the safety and efficacy of percutaneous mitral valve repair using the MitraClip™ device in patients with severely reduced systolic left ventricular (LV) function.

METHODS AND RESULTS

Among 777 MitraClip™ implantations included in the German mitral valve registry, we identified 256 patients suffering from severely reduced LV function [ejection fraction (EF) <30%] in whom successful percutaneous mitral valve repair was performed. Procedural safety, efficacy, and 1-year outcome was compared with 241 patients with preserved LV function (EF >50%) and 280 patients presenting with an EF 30-50% prior to MitraClip™ therapy. High procedural success rates, low periprocedural complication rates, and low residual mitral regurgitation grades at discharge were achieved throughout all groups. In-hospital mortality was low and comparable in all groups. After 1 year, mortality rates were 24.2% (EF <30%), 17.3% (EF 30-50%), and 18.9% (EF >50%). Major adverse cardiac or cardiovascular event rates were 29.7% (EF <30%), 24.4% (EF 30-50%), and 23.5% (EF >50%). Procedural failure was the main predictor for mortality in EF <30% patients (hazard ratio 10.38; 95% CI 3.71-29.02). Improved clinical symptoms were observed in the majority of patients in all groups. Thus, 69.5% of EF <30% patients improved by one or more New York Heart Association functional class. Compared with patients with preserved LV function, this is a significantly larger proportion (EF >50%: 56.8%; P < 0.05). Moreover, quality of life, being very poor at baseline, improved distinctively in severe heart failure patients.

CONCLUSION

In patients with severely reduced systolic LV function undergoing MitraClip™ therapy, procedural safety, efficacy, and clinical improvement after 1 year are comparable to patients with preserved LV function.

Immediate increase of cardiac output after percutaneous mitral valve repair (PMVR) determined by echocardiographic and invasive parameters: Patzelt: Increase of cardiac output after PMVR

BACKGROUND

Successful percutaneous mitral valve repair (PMVR) in patients with severe mitral regurgitation (MR) causes changes in hemodynamics. Echocardiographic calculation of cardiac output (CO) has not been evaluated in the setting of PMVR, so far. Here we evaluated hemodynamics before and after PMVR with the MitraClip system using pulmonary artery catheterization, transthoracic (TTE) and transesophageal (TEE) echocardiography.

METHODS

101 patients with severe MR not eligible for conventional surgery underwent PMVR. Hemodynamic parameters were determined during and after the intervention. We evaluated changes in CO and pulmonary artery systolic pressure before and after PMVR. CO was determined with invasive parameters using the Fick method (COi) and by a combination of TTE and TEE (COe).

RESULTS

All patients had successful clip implantation, which was associated with increased COi (from 4.6±1.4l/min to 5.4±1.6l/min, p<0.001). Furthermore, pulmonary artery systolic pressure (PASP) showed a significant decrease after PMVR (47.6±16.1 before, 44.7±15.5mmHg after, p=0.01). In accordance with invasive measurements, COe increased significantly (COe from 4.3±1.7l/min to 4.8±1.7l/min, p=0.003). Comparing both methods to calculate CO, we observed good agreement between COi and COe using Bland Altman plots.

CONCLUSIONS

CO increased significantly after PMVR as determined by echocardiography based and invasive calculation of hemodynamics during PMVR. COe shows good agreement with COi before and after the intervention and, thus, represents a potential non-invasive method to determine CO in patients with MR not accessible by conventional surgery.

One-year outcome of percutaneous mitral valve repair in patients with severe symptomatic mitral valve regurgitation

AIM

To investigate one-year outcomes after percutaneous mitral valve repair with MitraClip^® in patients with severe mitral regurgitation (MR).

METHODS

Our study investigated consecutive patients with symptomatic severe MR who underwent MitraClip^® implantation at the University Hospital Bergmannsheil from 2012 to 2014. The primary study end-point was all-cause mortality. Secondary end-points were degree of MR and functional status after percutaneous mitral valve repair.

RESULTS

The study population consisted of 46 consecutive patients (mean logistic EuroSCORE 32% ± 21%). The degree of MR decreased significantly (severe MR before MitraClip^® 100% vs after MitraClip^® 13%; P < 0.001), and the NYHA functional classes improved (NYHA III/IV before MitraClip^® 98% vs after MitraClip^® 35%; P < 0.001). The mortality rates 30 d and one year after percutaneous mitral valve repair were 4.3% and 19.5%, respectively. During the follow-up of 473 ± 274 d, 11 patients died (90% due to cardiovascular death). A pre-procedural plasma B-type natriuretic peptide level > 817 pg/mL was associated with all-cause mortality (hazard ratio, 6.074; 95%CI: 1.257-29.239; P = 0.012).

CONCLUSION

Percutaneous mitral valve repair with MitraClip^® has positive effects on hemodynamics and symptoms. Despite the study patients’ multiple comorbidities and extremely high operative risk, one-year outcomes after MitraClip^® are favorable. Elevated B-type natriuretic peptide levels indicate poorer mid-term survival.

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.