Patient selection for percutaneous mitral valve repair: insight from early clinical trial applications

One-Year Outcomes After MitraClip for Functional Mitral Regurgitation

BACKGROUND

Secondary mitral regurgitation (SMR) occurs in the absence of organic mitral valve disease and may develop as the left ventricle dilates or remodels or as a result of leaflet tethering with impaired coaptation, most commonly from apical and lateral distraction of the subvalvular apparatus, with late annular dilatation. The optimal therapy for SMR is unclear. This study sought to evaluate the 1-year adjudicated outcomes of all patients with SMR undergoing the MitraClip procedure in the EVEREST II (Endovascular Valve Edge-to-Edge Repair Study) Investigational Device Exemption program, which is comprised of the randomized clinical trial, the prospective High-Risk Registry, and the REALISM Continued Access Registry (Multicenter Study of the MitraClip System).

METHODS

Patients with 3+/4+ SMR enrolled in EVEREST II were stratified by non-high surgical risk (non-HR) and high surgical risk (HR) status (defined as Society of Thoracic Surgeons risk of mortality ≥12% or predefined risk factors). Clinical, echocardiographic, and functional outcomes at 1 year were evaluated.

RESULTS

A total of 616 patients (482 HR, 134 non-HR; mean age, 73.3±10.5 years; Society of Thoracic Surgeons risk, 10.2±6.9%) with SMR underwent the MitraClip procedure. At baseline, 80.5% of patients were in New York Heart Association class III/IV. Major adverse events at 30 days included death (3.6%), stroke (2.3%), and renal failure (1.5%). At discharge, 88.8% had MR ≤2+. At 1 year, there were 139 deaths, and the Kaplan-Meier estimate of freedom from mortality was 76.8%. The majority of surviving patients (84.7%) remained with MR ≤2+ and New York Heart Association class I/II (83.0%). Kaplan-Meier survival at 1 year was 74.1% in HR patients and 86.4% in non-HR patients ( P=0.0175). At 1 year, both groups achieved comparable MR reduction (MR ≤2+, 84.0% versus 87.0%) and improvement in left ventricular end-diastolic volume (-8.0 mL versus -12.7 mL), whereas New York Heart Association class I/II was found in 80.1% versus 91.8% ( P=0.008) of HR and non-HR patients, respectively. In HR patients, the annualized rate of heart failure hospitalizations decreased from 0.68 to 0.46 in the 12 months before to 12 months after the procedure ( P<0.0001).

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip in patients with secondary MR is associated with acceptable safety, reduction of MR severity, symptom improvement, and positive ventricular remodeling.

CLINICAL TRIAL REGISTRATION

https://www.clinicaltrials.gov . Unique identifiers: NCT00209274, NCT01940120, and NCT01931956.

Five-year outcomes of transcatheter reduction of significant mitral regurgitation in high-surgical-risk patients

Objectives

This study evaluates the 5-year clinical outcomes of transcatheter mitral valve (MV) repair with the MitraClip device in patients at high risk for MV surgery treated in the Endovascular Valve Edge-to-Edge Repair (EVEREST) II High Risk Study (HRS).

Methods

Patients with mitral regurgitation (MR) 3+ or 4+ and predicted surgical mortality risk ≥12% or surgeon assessment based on prespecified high-risk factors were enrolled. Patients prospectively consented to 5 years of follow-up.

Results

At 5 years, clinical follow-up was achieved in 90% of 78 enrolled patients. The rate of postprocedural adverse events declined from 30 days to 1 year follow-up and was stable thereafter through 5 years. Two patients (2.6%) developed mitral stenosis (MS). Two patients underwent MV surgery, including one due to MS. A total of 42 deaths were reported through 5 years. Effectiveness measures at 5 years showed reductions in MR severity to ≤2+ in 75% of patients (p=0.0107), left ventricular (LV) end-diastolic volume (−38.2 mL; 95% CI −55.0 to –21.4; p<0.0001) and LV end-systolic volume (−14.6 mL; 95% CI −27.7 to −1.5; p=0.0303) compared with baseline. The New York Heart Association (NYHA) functional class improved from baseline to 5 years (p<0.005), and septal-lateral annular dimensions remained stable with no indication of mitral annular dilation through 5 years.

Conclusions

The EVEREST II HRS demonstrated long-term safety and efficacy of MitraClip in high-surgical-risk patients through 5 years. The observed mortality was most likely a consequence of the advanced age and comorbidity profile of the enrolled patients, while improvements in NYHA class in surviving patients were durable through long-term follow-up.

Trial registration number

NCT01940120.

Cardiovascular events and hospital resource utilization pre- and post-transcatheter mitral valve repair in high-surgical risk patients

MitraClip is an approved therapy for mitral regurgitation (MR); however, health care resource utilization pre- and post-MitraClip remains understudied.

METHODS

Patients with functional and degenerative MR at high surgical risk in the EVEREST II High-Risk Registry and REALISM Continued-Access Study were linked to Medicare data. Pre- and post-MitraClip all-cause death, stroke, myocardial infarction, heart failure (HF), and bleeding hospitalizations were identified. Inpatient costs, adjusted to 2010 US dollars, were calculated, and event rate ratios and cost ratios were estimated with multivariable modeling.

RESULTS

Among 403 linked patients, the mean age was 80 years, 60% were male, mean baseline left ventricular ejection fraction was 49.6%, 83.3% were New York Heart Association class III/IV, 78.2% were MR grade 3+/4+, and 63.3% had functional MR. All-cause hospitalization decreased from 1,854 to 1,435/1,000 person-years (P<.001). HF hospitalization decreased following MitraClip (749 vs 332/1000 person-years, P<.001), but bleeding increased (199 vs 298/1000 person-years, P<.001). Changes in stroke and myocardial infarction were not statistically significant. Overall mean Medicare costs per patient were similar pre- and post-MitraClip, although there was a significant decrease in mean costs among those that survived a full year after MitraClip ($18,131 [SD $25,130] vs $11,679 [SD $22,486], P=.02).

CONCLUSIONS

MitraClip was associated with a reduced rate of all-cause and HF hospitalizations and an increased rate of bleeding hospitalizations. One-year Medicare costs were reduced in those who survived a full year after the MitraClip procedure. Payors and providers seeking to reduce HF hospitalizations and associated Medicare costs may consider MitraClip among appropriate patients likely to survive 1 year.

AVJ-514 Trial - Baseline Characteristics and 30-Day Outcomes Following MitraClip® Treatment in a Japanese Cohort

BACKGROUND

The MitraClip^®system is a transcatheter-based therapeutic option for patients with chronic mitral regurgitation (MR) who are at high risk for surgery. A prospective, multicenter, single-arm study was initiated to confirm the transferability of this system to Japan.Methods and Results:Patients with symptomatic chronic moderate-to-severe (3+) or severe (4+) functional or degenerative MR with a Society of Thoracic Surgery (STS) score ≥8%, or the presence of 1 predefined risk factor were enrolled. Patients with left ventricular (LV) ejection fraction (EF) <30% were excluded. MR severity and LV function were assessed by an independent echocardiography core lab. Primary outcome included major adverse events (MAE) at 30 days and acute procedural success (APS). A total of 30 patients (age: 80±7 years; STS score: 10.3%±6.6%) were treated with the MitraClip^®. At baseline, all patients had MR 3+/4+ with 53%/47% patients with degenerative/functional etiology with mean LVEF of 50.2±12.8%, and 37% of patients were NYHA class III/IV. APS was achieved in 86.7% with no occurrence of MAE. At 30 days, 86.7% of patients had MR ≤2+ and 96.7% were NYHA class I/II.

CONCLUSIONS

The MitraClip^®procedure resulted in clinically meaningful improvements in MR severity, function and quality of life measures, and low MAE rates. These early results suggest the transferability of this therapy to appropriately selected Japanese patients. (Trial Registration: clinicaltrials.gov Identifier NCT02520310.).

Real-world cost effectiveness of MitraClip combined with Medical Therapy Versus Medical therapy alone in patients with moderate or severe mitral regurgitation

BACKGROUND

We evaluated the real-world cost-effectiveness of the MitraClip system (Abbott Vascular Inc., Menlo Park, CA) plus medical therapy for patients with moderate/severe mitral regurgitation, as compared with medical therapy (MT) alone.

METHODS

Clinical records of patients with moderate to severe functional mitral regurgitation treated with MitraClip (N=232) or with MT (N=151) were collected and outcome analyzed with propensity score adjustment to reduce selection bias. Twelve-month outcomes were modeled over a lifetime horizon to conduct a cost-effectiveness analysis, in the payer's perspective. Costs and benefits were discounted at an annual rate of 3.5%.

RESULTS

After propensity score adjustment, the average treatment effect was -9.5% probability of dying at 12months and, following lifetime modeling, 3.35±0.75 incremental life years and 3.01±0.57 incremental quality-adjusted life years. MitraClip contributed to a higher decrease in re-hospitalizations at 12months (difference=-0.54±0.08) and generated a more likely improvement in the New York Heart Association (NYHA) class at 12months versus NYHA at enrollment. Incremental costs, adapted to five possible scenarios, ranged from 14,493 to 29,795 € contributing to an incremental cost-effectiveness ratio ranging from 4796 to 7908 €.

CONCLUSIONS

Compared to MT alone and given conventional threshold values, MitraClip can be considered a cost-effective procedure. The cost-effectiveness of MitraClip is in line or superior to the one of other non-pharmaceutical strategies for heart failure.

Percutaneous mitral valve repair for mitral regurgitation in high-risk patients: results of the EVEREST II study

BACKGROUND

The EVEREST II (Endovascular Valve Edge-to-Edge REpair STudy) High-Risk registry and REALISM Continued Access Study High-Risk Arm are prospective registries of patients who received the MitraClip device (Abbott Vascular, Santa Clara, California) for mitral regurgitation (MR) in the United States.

OBJECTIVES

The purpose of this study was to report 12-month outcomes in high-risk patients treated with the percutaneous mitral valve edge-to-edge repair.

METHODS

Patients with grades 3 to 4+ MR and a surgical mortality risk of ≥12%, based on the Society of Thoracic Surgeons risk calculator or the estimate of a surgeon coinvestigator following pre-specified protocol criteria, were enrolled.

RESULTS

In the studies, 327 of 351 patients completed 12 months of follow-up. Patients were elderly (76 ± 11 years of age), with 70% having functional MR and 60% having prior cardiac surgery. The mitral valve device reduced MR to ≤2+ in 86% of patients at discharge (n = 325; p < 0.0001). Major adverse events at 30 days included death in 4.8%, myocardial infarction in 1.1%, and stroke in 2.6%. At 12 months, MR was ≤2+ in 84% of patients (n = 225; p < 0.0001). From baseline to 12 months, left ventricular (LV) end-diastolic volume improved from 161 ± 56 ml to 143 ± 53 ml (n = 203; p < 0.0001) and LV end-systolic volume improved from 87 ± 47 ml to 79 ± 44 ml (n = 202; p < 0.0001). New York Heart Association functional class improved from 82% in class III/IV at baseline to 83% in class I/II at 12 months (n = 234; p < 0.0001). The 36-item Short Form Health Survey physical and mental quality-of-life scores improved from baseline to 12 months (n = 191; p < 0.0001). Annual hospitalization rate for heart failure fell from 0.79% pre-procedure to 0.41% post-procedure (n = 338; p < 0.0001). Kaplan-Meier survival estimate at 12 months was 77.2%.

CONCLUSIONS

The percutaneous mitral valve device significantly reduced MR, improved clinical symptoms, and decreased LV dimensions at 12 months in this high-surgical-risk cohort. (Endovascular Valve Edge-to-Edge REpair STudy [EVERESTIIRCT]; NCT00209274).

Percutaneous mitral valve repair: potential in heart failure management

As a large portion of the US demographic advances into the later decades of life, the incidence of valvular heart disease is expected to increase. Mitral regurgitation (MR) caused by primary valve abnormality (degenerative) or secondary to cardiomyopathy (functional) is an important cause of heart failure. Management of valvular heart disease is expected to account for a large segment of services provided to heart failure patients. Recent years have seen a transition from surgical therapy to minimally invasive techniques, specifically percutaneous approaches for the correction of heart valve disease. The double orifice technique of mitral valve repair using the MitraClip System (Abbott Vascular, Menlo Park, CA) is one of many percutaneous approaches to treat significant MR. This technique is effective in patients with both degenerative and functional MR, reducing MR severity and improving heart failure symptoms. Broad acceptance of this percutaneous technology requires collaboration among cardiologists and cardiac surgeons in centers with superior catheter experience and knowledge of echocardiography.

Magnetic resonance cardiac vein imaging: relation to mitral valve annulus and left circumflex coronary artery

OBJECTIVES

To evaluate in vivo anatomical relationships between the coronary sinus-great cardiac vein (CS-GCV), the mitral valve annulus (MVA), and left circumflex coronary artery (LCX) with cardiovascular magnetic resonance.

BACKGROUND

The CS-GCV has become an anatomical structure of interest because it provides a way of access to the heart for a number of interventional procedures. Previous reports demonstrate that the postulated close anatomical proximity of the CS-GCV to the MVA does not always hold true in patients, both in autopsy specimens and in vivo by computed tomography.

METHODS

In 31 participants (24 volunteers and 7 patients; 15 men; 42 +/- 19 years), cardiovascular magnetic resonance was performed for noninvasive evaluation of the coronary sinus and of the coronary arteries using whole-heart imaging and intravascular contrast agents. Three-dimensional reconstructions, standard orthogonal planes, and unprocessed raw data were used to assess CS-GCV anatomy and its relation to the MVA and the LCX along their entire course.

RESULTS

The CS-GCV was located behind the left atrium in all examined participants, at a minimum distance of 8.6 +/- 3.9 mm from the MVA. In 80% of the participants, the LCX crossed the CS-GCV inferiorly, between the CS-GCV and the MVA. The CS-GCV and the LCX had a parallel course for 26.2 +/- 23.0 mm, with great variability of location and length. In several participants, the CS-GCV had a long parallel course, but in other participants, the LCX crossed below the CS-GCV at a discrete point.

CONCLUSIONS

In all participants, the CS-GCV coursed behind the left atrium rather than behind the MVA. In the majority of the participants, the LCX coursed between the CS-GCV and the MVA. These anatomical relationships should be kept in mind when referring a patient for interventional procedures requiring the access to the CS-GCV, and cardiovascular magnetic resonance might provide important information for the selection of candidates for these procedures.