Dose-dependent effects of Dnmt3a in an inducible murine model of KrasG12D-driven leukemia.

DNMT3A mutations are frequently found in clonal hematopoiesis and a variety of hematologic malignancies, including acute myeloid leukemia. An assortment of mouse models have been engineered to explore the tumorigenic potential and malignant lineage bias due to loss of function of DNMT3A in consort with commonly comutated genes in myeloid malignancies, such as Flt3, Nras, Kras, and c-Kit. We employed several tamoxifen-inducible Cre-ERT2 murine model systems to study the effects of constitutively active KrasG12D-driven myeloid leukemia (Kras) development together with heterozygous (3aHet) or homozygous Dnmt3a deletion (3aKO). Due to the rapid generation of diverse nonhematologic tumors appearing after tamoxifen induction, we employed a transplantation model. With pretransplant tamoxifen induction, most Kras mice died quickly of T-cell malignancies regardless of Dnmt3a status. Using posttransplant induction, we observed a dose-dependent effect of DNMT3A depletion that skewed the leukemic phenotype toward a myeloid lineage. Specifically, 64% of 3aKO/Kras mice had exclusively myeloid disease compared with 36% of 3aHet/Kras and only 13% of Kras mice. Here, 3aKO combined with Kras led to increased disease burden, multiorgan infiltration, and faster disease progression. DOT1L inhibition exerted profound antileukemic effects in malignant 3aKO/Kras cells, but not malignant cells with Kras mutation alone, consistent with the known sensitivity of DNMT3A-mutant leukemia to DOT1L inhibition. RNAseq from malignant myeloid cells revealed that biallelic Dnmt3a deletion was associated with loss of cell-cycle regulation, MYC activation, and TNF⍺ signaling. Overall, we developed a robust model system for mechanistic and preclinical investigations of acute myeloid leukemia with DNMT3A and Ras-pathway lesions.

A clinical impact study of dermatologists' use of diagnostic gene expression profile testing to guide patient management.

Aim: Cutaneous melanocytic neoplasms with diagnostic and/or clinical ambiguity pose patient management challenges. Methods: Six randomized case scenarios with diagnostic/clinical uncertainty were described with/without a benign or malignant diagnostic gene expression profile (GEP) result. Results: Clinical impact was assessed by reporting the mean increase/decrease of management changes normalized to baseline (n = 32 dermatologists). Benign GEP results prompted clinicians to decrease surgical margins (84.2%). Malignant GEP results escalated surgical excision recommendations (100%). A majority (72.2%) reduced and nearly all (98.9%) increased follow-up frequency for benign or malignant GEP results, respectively. There was an overall increase in management plan confidence with GEP results. Conclusion: Diagnostic GEP tests help guide clinical decision-making in a variety of diagnostically ambiguous or clinicopathologically discordant scenarios.

Dermatologists' use of diagnostic gene expression profiles for personalized patient care. When your doctor takes a piece of a mole, that mole is looked at under the microscope by a pathologist. The pathologist is responsible for figuring out if the mole is dangerous or not. Dangerous moles are removed with surgery to make sure all the dangerous tissue is gone. Moles without a health threat are left alone. Sometimes figuring out how dangerous a mole is is difficult. The pathologist may not provide the doctor with enough information for them to know how to treat your mole. There is a test that can provide information on whether your mole is unsafe. This test is called diagnostic gene expression profiling or GEP. In this study, GEP is used to help doctors figure out how to treat a mole and how often the patient should be seen in the office for skin checks. With GEP, important changes in patient treatment were identified. These include the need for an additional surgery, how much healthy tissue should be removed during surgery and how often the patient should be seen in the office. For suspicious moles where the pathology report is unclear, GEP can provide information that leads to more appropriate and personalized patient care.

Ancillary diagnostic gene expression profile testing for ambiguous cutaneous melanocytic lesions helps optimize dermatologist recommendations for excision margin and follow-up.

Mortality Associated With Proportionality of Secondary Mitral Regurgitation After Transcatheter Mitral Valve Repair: North American Mitraclip for Functional Mitral Regurgitation Registry.

The association, if any, between the effective regurgitant orifice area (EROA) to left ventricular end-diastolic volume (LVEDV) ratio and 1-year mortality is controversial in patients who undergo mitral transcatheter edge-to-edge repair (m-TEER) with the MitraClip system (Abbott Vascular, Santa Clara, CA). This study's objective was to determine the association between EROA/LVEDV and 1-year mortality in patients who undergo m-TEER with MitraClip. In patients with severe secondary (functional) mitral regurgitation (MR), we analyzed registry data from 11 centers using generalized linear models with the generalized estimating equations approach. We studied 525 patients with secondary MR who underwent m-TEER. Most patients were male (63%) and were New York Heart Association class III (61%) or IV (21%). Mitral regurgitation was caused by ischemic cardiomyopathy in 51% of patients. EROA/LVEDV values varied widely, with median = 0.19 mm2/ml, interquartile range [0.12,0.28] mm2/ml, and 187 patients (36%) had values <0.15 mm2/ml. Postprocedural mitral regurgitation severity was substantially alleviated, being 1+ or less in 74%, 2+ in 20%, 3+ in 4%, and 4+ in 2%; 1-year mortality was 22%. After adjustment for confounders, the logarithmic transformation (Ln) of EROA/LVEDV was associated with 1-year mortality (odds ratio 0.600, 95% confidence interval 0.386 to 0.933, p = 0.023). A higher Society of Thoracic Surgeons risk score was also associated with increased mortality. In conclusion, lower values of Ln(EROA/LVEDV) were associated with increased 1-year mortality in this multicenter registry. The slope of the association is steep at low values but gradually flattens as Ln(EROA/LVEDV) increases.

1-Year Outcomes With Fourth-Generation Mitral Valve Transcatheter Edge-to-Edge Repair From the EXPAND G4 Study.

BACKGROUND: The fourth-generation mitral transcatheter edge-to-edge repair (M-TEER) device introduced an improved clip deployment sequence, independent leaflet grasping, and 2 wider clip sizes to tailor the treatment of patients with mitral regurgitation (MR) for a broad range of anatomies. The 30-day safety and effectiveness of the fourth-generation M-TEER device were previously demonstrated. OBJECTIVES: The aim of this study was to evaluate 1-year outcomes in a contemporary, real-world cohort of subjects treated with the MitraClip G4 system. METHODS: EXPAND G4 is an ongoing prospective, multicenter, international, single-arm study that enrolled subjects with primary and secondary MR. One-year outcomes included MR severity (echocardiographic core laboratory assessed), heart failure hospitalization, all-cause mortality, functional capacity (NYHA functional class), and quality of life (Kansas City Cardiomyopathy Questionnaire). RESULTS: A total of 1,164 subjects underwent M-TEER from 2020 to 2022. At 1 year, there was a durable reduction in MR to mild or less in 92.6% and to none or trace in 44.2% (P < 0.0001 vs baseline). Few subjects had major adverse events through 1 year (<2% for myocardial infarction, surgical reintervention, or single-leaflet device attachment). The 1-year Kaplan-Meier estimates for all-cause mortality and heart failure hospitalization were 12.3% and 16.9%. Significant improvements in functional capacity (NYHA functional class I or II in 82%; P < 0.0001 vs baseline) and quality of life (18.5-point Kansas City Cardiomyopathy Questionnaire overall summary score improvement; P < 0.0001) were observed. CONCLUSIONS: M-TEER with the fourth-generation M-TEER device was safe and effective at 1 year, with durable reductions in MR severity to ≤1+ in more than 90% of patients and concomitant improvements in functional status and quality of life.

Real-World Outcomes of Fourth-Generation Mitral Transcatheter Repair: 30-Day Results From EXPAND G4.

BACKGROUND: The fourth-generation MitraClip G4 System builds on the previous NTR/XTR system with additional wider clip sizes (NTW and XTW), an independent grasping feature, and an improved clip deployment sequence. OBJECTIVES: The primary objective of this study was to assess the safety and performance of the MitraClip G4 System within a contemporary real-world setting. METHODS: EXPAND G4 is a prospective, multicenter, international, single-arm, postapproval study that enrolled patients with primary (degenerative) mitral regurgitation (MR) and secondary (functional) MR at 60 centers. Follow-up of the full cohort has been conducted through 30 days. Echocardiograms were analyzed by an echocardiography core laboratory. Study outcomes included MR severity, functional capacity measured by NYHA functional class, quality of life measured using the Kansas City Cardiomyopathy Questionnaire, major adverse event rates, and all-cause mortality. RESULTS: In EXPAND G4, 1,141 subjects with primary MR and secondary MR were treated from March 2021 to February 2022. Implantation and acute procedural success rates were 98.0% and 96.2%, respectively, with a mean of 1.4 ± 0.6 clips implanted per subject. MR was significantly reduced at 30 days compared with baseline (98% achieved MR ≤ 2+, and 91% achieved MR ≤ 1+; P < 0.0001). Functional capacity and quality of life were substantially improved, with 83% of patients achieving NYHA functional class I or II. Likewise, an 18-point improvement was observed in Kansas City Cardiomyopathy Questionnaire summary scores compared with baseline. The composite major adverse event rate was 2.7%, and the all-cause death rate was 1.3% at 30 days. CONCLUSIONS: This study demonstrates for the first time the effectiveness and safety of MitraClip G4 System at 30 days in a cohort of >1,000 patients with MR in a contemporary, real-world setting.

Expanding the Spectrum of TEER Suitability: Evidence From the EXPAND G4 Post Approval Study.

BACKGROUND: Anatomical and clinical criteria to define mitral transcatheter edge-to-edge repair (TEER) "unsuitability" have been proposed on the basis of a Heart Valve Collaboratory consensus opinion from physician experience with early-generation TEER devices but lacked an evidence-based approach. OBJECTIVES: The aim of this study was to explore the spectrum of TEER suitability using echocardiographic and clinical outcomes from the EXPAND G4 real-world postapproval study. METHODS: EXPAND G4 is a global, prospective, multicenter, single-arm study that enrolled 1,164 subjects with mitral regurgitation (MR) treated with the MitraClip G4 System. Three groups were defined using the Heart Valve Collaboratory TEER unsuitability criteria: 1) risk of stenosis (RoS); 2) risk of inadequate MR reduction (RoIR); and 3) subjects with baseline moderate or less MR (MMR). A TEER-suitable (TS) group was defined by the absence of these characteristics. Endpoints included independent core laboratory-assessed echocardiographic characteristics, procedural outcomes, MR reduction, NYHA functional class, Kansas City Cardiomyopathy Questionnaire score, and major adverse events through 30 days. RESULTS: Subjects in the RoS (n = 56), RoIR (n = 54), MMR (n = 326), and TS (n = 303) groups had high 30-day MR reduction rates (≤1+: RoS 97%, MMR 93%, and TS 91%; ≤2+: RoIR 94%). Thirty-day improvements in functional capacity (NYHA functional class I or II at 30 days vs baseline: RoS 94% vs 29%, RoIR 88% vs 30%, MMR 79% vs 26%, and TS 83% vs 33%) and quality of life (change in Kansas City Cardiomyopathy Questionnaire score: RoS +27 ± 26, RoIR +16 ± 26, MMR +19 ± 26, and TS +19 ± 24) were safely achieved in all groups, with low major adverse events (<3%) and all-cause mortality (RoS 1.8%, RoIR 0%, MMR 1.5%, and TS 1.3%). CONCLUSIONS: Patients previously deemed TEER unsuitable can be safely and effectively treated with the mitral TEER fourth-generation device.

Transcatheter Left Atrial Appendage Exclusion: Preclinical and Early Clinical Results With the Laminar Device.

BACKGROUND: The Laminar device rotates and closes the left atrial appendage (LAA) using an integrated ball and lock that excludes and eliminates the LAA pouch. There is a low device surface area, minimizing the risk of peridevice leak (PDL) and device-related thrombus (DRT) formation. OBJECTIVES: This study evaluates the safety and efficacy of the Laminar LAA exclusion device in healthy animals and human subjects with nonvalvular atrial fibrillation at risk of ischemic stroke and systemic thromboembolism. METHODS: The preclinical study implanted the Laminar device into canine subjects that underwent transesophageal echocardiography (TEE) and fluoroscopic evaluation, followed by necropsy and histological assessment at 45 and 150-days post-implant. The early clinical study implanted the device in human subjects, followed to 12 months postimplantation. Procedural success was defined as device implantation in the intended location without residual LAA leak >5 mm as seen by TEE. Safety endpoints included freedom from stroke, systemic embolism, pericardial effusion, or tamponade, life-threatening/major bleeding, or death. RESULTS: The Laminar device was successfully implanted in 10 canines. In all animals at 45 days and 150 days, no PDL or DRT was found, and histological examination showed fully closed LAAs covered with neo-endocardium. The device was successfully implanted in 15 human subjects with no safety events out to 12 months postimplantation. All subjects had successful protocol-defined LAA closure without DRT at 45 days by TEE and computed tomography, which remained stable through 12 months' follow-up. CONCLUSIONS: The preclinical and early clinical results demonstrate a promising safety and efficacy profile for the Laminar LAA exclusion device.

Iatrogenic Atrial Septal Defect Closure Through the Steerable Guide Catheter: Description of Technique and Single-Center Experience.

OBJECTIVES: To introduce a novel method of direct iatrogenic atrial septal defect (iASD) closure through the MitraClip steerable guide catheter (SGC). BACKGROUND: MitraClip implantation requires transseptal puncture and the creation of an iASD. There are relatively rare instances, such as hemodynamically significant shunting or concerns for embolus, where iASD must be closed during index procedure. In these instances, it may be beneficial to not give up access to left atrium. METHODS: We retrospectively reviewed all iASD closures during MitraClip implantation at our institution from 2015 to 2020. Cases where an ASD occluder was deployed directly through SGC were included. RESULTS: Eleven patients had immediate iASD closure through the SGC. Indications for using this method included concern for paradoxical embolus, large defect size and/or significant shunting. Closure device sizes ranged from 8 to 22 mm. Mean time from removal of clip delivery system to occlusion of iASD was 14.6 minutes. There were no procedural complications related to iASD closure using this method. CONCLUSION: Closure of iASD intra-procedurally directly through transseptal guide sheath via the method described was safe and allowed for continuous left atrium access.

Randomized Trials Are Needed for Transcatheter Mitral Valve Replacement.

Transcatheter mitral valve replacement (TMVR) is a new therapy for treating symptomatic mitral regurgitation (MR) and stenosis. The proposed benefit of TMVR is the predictable, complete elimination of MR, which is less certain with transcatheter repair technologies such as TEER (transcatheter edge-to-edge repair). The potential benefit of MR elimination with TMVR needs to be rigorously evaluated against its risks which include relative procedural invasiveness, need for anticoagulation, and chronic structural valve deterioration. Randomized controlled trials (RCTs) are a powerful method for evaluating the safety and effectiveness of TMVR against current standard of care transcatheter therapies, such as TEER. RCTs not only help with the assessment of benefits and risks, but also with policies for determining operator or institutional requirements, resource utilization, and reimbursement. In this paper, the authors provide recommendations and considerations for designing pivotal RCTs for first-in-class TMVR devices.

Modeling IKZF1 lesions in B-ALL reveals distinct chemosensitivity patterns and potential therapeutic vulnerabilities.

IKAROS family zinc finger 1 (IKZF1) alterations represent a diverse group of genetic lesions that are associated with an increased risk of relapse in B-cell acute lymphoblastic leukemia. Due to the heterogeneity of concomitant lesions, it remains unclear how IKZF1 abnormalities directly affect cell function and therapy resistance, and whether their consideration as a prognostic indicator is valuable in improving outcome. CRISPR/Cas9 strategies were used to engineer multiple panels of isogeneic lymphoid leukemia cell lines with a spectrum of IKZF1 lesions to measure changes in chemosensitivity, gene expression, cell cycle, and in vivo engraftment that can be linked to loss of IKAROS protein. IKZF1 knockout and heterozygous null cells displayed relative resistance to a number of common therapies for B-cell acute lymphoblastic leukemia, including dexamethasone, asparaginase, and daunorubicin. Transcription profiling revealed a stem/myeloid cell-like phenotype and JAK/STAT upregulation after IKAROS loss. A CRISPR homology-directed repair strategy was also used to knock-in the dominant-negative IK6 isoform into the endogenous locus, and a similar drug resistance profile, with the exception of retained dexamethasone sensitivity, was observed. Interestingly, IKZF1 knockout and IK6 knock-in cells both have significantly increased sensitivity to cytarabine, likely owing to marked downregulation of SAMHD1 after IKZF1 knockout. Both types of IKZF1 lesions decreased the survival time of xenograft mice, with higher numbers of circulating blasts and increased organ infiltration. Given these findings, exact specification of IKZF1 status in patients may be a beneficial addition to risk stratification and could inform therapy.

Sex-Specific Outcomes of Transcatheter Mitral-Valve Repair and Medical Therapy for Mitral Regurgitation in Heart Failure.

OBJECTIVES: This study sought to assess the sex-specific outcomes in patients with heart failure (HF) with 3+ and 4+ secondary mitral regurgitation (SMR) treated with transcatheter mitral valve repair (TMVr) plus guideline-directed medical therapy (GDMT) versus GDMT alone in the COAPT trial. BACKGROUND: The impact of sex in patients with HF and severe SMR treated with TMVr with the MitraClip compared with GDMT alone is unknown. METHODS: Patients were randomized 1:1 to TMVr versus GDMT alone. Two-year outcomes were examined according to sex. RESULTS: Among 614 patients, 221 (36.0%) were women. Women were younger than men and had fewer comorbidities, but reduced quality of life and functional capacity at baseline. In a joint frailty model accounting for the competing risk of death, the 2-year cumulative incidence of the primary endpoint of all HF hospitalizations (HFH) was higher in men compared with women treated with GDMT alone. However, the relative reduction in HFHs with TMVr was greater in men (HR: 0.43; 95% CI: 0.34-0.54) than women (HR: 0.78; 95% CI: 0.57-1.05) (Pinteraction = 0.002). A significant interaction between TMVr versus GDMT alone treatment and time was present for all HFHs in women (HR: 0.57; 95% CI: 0.39-0.84, and HR: 1.39; 95% CI: 0.83-2.33 between 0-1 year and 1-2 years after randomization, respectively, Pinteraction = 0.007) but not in men (HR: 0.48; 95% CI: 0.36-0.64, and HR: 0.33; 95% CI: 0.21-0.51; Pinteraction = 0.16). Female sex was independently associated with a lower adjusted risk of death at 2 years (HR: 0.64; 95% CI: 0.46-0.90; P = 0.011). TMVr consistently reduced 2-year mortality compared with GDMT alone, irrespective of sex (Pinteraction = 0.99). CONCLUSIONS: In the COAPT trial, TMVr with the MitraClip resulted in improved clinical outcomes compared with GDMT alone, irrespective of sex. However, the impact of TMVr in reducing HFH was less pronounced in women compared with men beyond the first year after treatment. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Tria] [COAPT]; NCT01626079).

Relationship Between Residual Mitral Regurgitation and Clinical and Quality-of-Life Outcomes After Transcatheter and Medical Treatments in Heart Failure: COAPT Trial.

BACKGROUND: In the randomized COAPT trial (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation), among 614 patients with heart failure with 3+ or 4+ secondary mitral regurgitation (MR), transcatheter mitral valve repair (TMVr) with the MitraClip reduced MR, heart failure hospitalizations, and mortality and improved quality of life compared with guideline-directed medical therapy (GDMT) alone. We aimed to examine the prognostic relationship between MR reduction and outcomes after TMVr and GDMT alone. METHODS: Outcomes in COAPT between 30 days and 2 years were examined on the basis of the severity of residual MR at 30 days. RESULTS: TMVr-treated patients had less severe residual MR at 30 days than GDMT-treated patients (0/1+, 2+, and 3+/4+: 72.9%, 19.9%, and 7.2% versus 8.2%, 26.1%, and 65.8%, respectively [P<0.0001]). The rate of composite death or heart failure hospitalizations between 30 days and 2 years was lower in patients with 30-day residual MR of 0/1+ and 2+ compared with patients with 30-day residual MR of 3+/4+ (37.7% versus 49.5% versus 72.2%, respectively [P<0.0001]). This relationship was consistent in the TMVr and GDMT arms (Pinteraction=0.92). The improvement in Kansas City Cardiomyopathy Questionnaire score from baseline to 30 days was maintained between 30 days and 2 years in patients with 30-day MR ≤2+ but deteriorated in those with 30-day MR 3+/4+ (-0.3±1.7 versus -9.4±4.6 [P=0.0008]) consistently in both groups (Pinteraction=0.95). CONCLUSIONS: In the COAPT trial, reduced MR at 30 days was associated with greater freedom from death or heart failure hospitalizations and improved quality of life through 2-year follow-up whether the MR reduction was achieved by TMVr or GDMT. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01626079.

The Yin-Yang Sign of Severe Mitral Regurgitation.

In select patients with severe, eccentric mitral regurgitation, we have observed that the regurgitant jet may entrain blood along the left atrial wall to produce a Chinese yin-yang symbol on color Doppler. This clinical imaging series demonstrates this unique phenomenon in an 81-year-old woman with symptomatic, severe, functional mitral regurgitation secondary to non-ischemic cardiomyopathy who was referred for transcatheter mitral valve repair. The yin-yang symbol resolved on transthoracic echocardiography after placement of 2 MitraClip NTR devices.

MitraClip Implantation Guided by Volumetric Intracardiac Echocardiography: Technique and Feasibility in Patients Intolerant to Transesophageal Echocardiography.

Transesophageal echo (TEE) guidance is essential for successful MitraClip implantation. In patients intolerant to TEE, options are limited. Three patients, with contraindications to TEE, underwent MitraClip implantation using volumetric intracardiac echo (vICE). All patients had severe symptomatic degenerative mitral regurgitation (MR) and had successful implantation of at least one clip with reduction of MR to ≤2+ maintained at 30d follow-up. All patients had improvement in functional status without any adverse clinical, clip, or vICE related events. We discuss in detail the technical considerations and limitations to performing the MitraClip procedure with vICE guidance.

Transseptal chordal replacement: early experience.

Chordal replacement is a fundamental technique used in the surgical repair of primary mitral regurgitation, and can be an effective means of preserving the native valve without leaflet resection. Surgical chordal replacement can be challenging since it is performed on an open, non-beating heart, and choosing the correct chord length to restore the zone of coaptation requires both intuition and skill. Developing transcatheter, transfemoral, and transseptal approaches to mitral valve chordal replacement presents the opportunity for safer and potentially earlier treatment of patients with primary mitral regurgitation. In particular, transcatheter methods will allow adjustment of chordal length and position real-time on a beating heart under echocardiographic guidance. In this manuscript, we review the current transcatheter transseptal technologies in development and discuss the various issues related to device design, efficacy, durability, and clinical trial design.

Transseptal direct complete annuloplasty: early experience.

Annuloplasty is a fundamental component of surgical mitral valve repair, and is employed in nearly 100% of repair operations for both primary and secondary mitral regurgitation (SMR). Developing transcatheter techniques to replicate surgical annuloplasty has been the focus of significant innovation and development in recent years. Since many patients are not offered surgery due to high perceived surgical risk, transcatheter approaches will provide new treatment options. In this manuscript, we review technologies which allow transseptal and transcatheter mitral valve (MV) annuloplasty.

3-Year Outcomes of Transcatheter Mitral Valve Repair in Patients With Heart Failure.

BACKGROUND: In the COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial, transcatheter mitral valve repair (TMVr) resulted in fewer heart failure hospitalizations (HFHs) and lower mortality at 24 months in patients with heart failure (HF) with mitral regurgitation (MR) secondary to left ventricular dysfunction compared with guideline-directed medical therapy (GDMT) alone. OBJECTIVES: This study determined if these benefits persisted to 36 months and if control subjects who were allowed to cross over at 24 months derived similar benefit. METHODS: This study randomized 614 patients with HF with moderate-to-severe or severe secondary MR, who remained symptomatic despite maximally tolerated GDMT, to TMVr plus GDMT versus GDMT alone. The primary effectiveness endpoint was all HFHs through 24-month follow-up. Patients have now been followed for 36 months. RESULTS: The annualized rates of HFHs per patient-year were 35.5% with TMVr and 68.8% with GDMT alone (hazard ratio [HR]: 0.49; 95% confidence interval [CI]: 0.37 to 0.63; p < 0.001; number needed to treat (NNT) = 3.0; 95% CI: 2.4 to 4.0). Mortality occurred in 42.8% of the device group versus 55.5% of control group (HR: 0.67; 95% CI: 0.52 to 0.85; p = 0.001; NNT = 7.9; 95% CI: 4.6 to 26.1). Patients who underwent TMVr also had sustained 3-year improvements in MR severity, quality-of-life measures, and functional capacity. Among 58 patients assigned to GDMT alone who crossed over and were treated with TMVr, the subsequent composite rate of mortality or HFH was reduced compared with those who continued on GDMT alone (adjusted HR: 0.43; 95% CI: 0.24 to 0.78; p = 0.006). CONCLUSIONS: Among patients with HF and moderate-to-severe or severe secondary MR who remained symptomatic despite GDMT, TMVr was safe, provided a durable reduction in MR, reduced the rate of HFH, and improved survival, quality of life, and functional capacity compared with GDMT alone through 36 months. Surviving patients who crossed over to device treatment had a prognosis comparable to those originally assigned to transcatheter therapy. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation [COAPT]; NCT01626079).