Implications of Atrial Fibrillation on the Mechanisms of Mitral Regurgitation and Response to MitraClip in the COAPT Trial

Secondary Mitral Regurgitation: Updated Review with Focus on Percutaneous Interventional Management

Secondary mitral regurgitation (SMR) is associated with increased mortality and heart failure hospitalizations. The management of heart failure patients with SMR is complex and requires a multidisciplinary Heart Team approach. Guideline-directed medical therapies remain fundamental, yet in a proportion of patients SMR persists. In the past decade, transcatheter edge-to-edge repair (TEER) has been shown to improve survival in patients with SMR who remain symptomatic despite medical therapy. Technical advancements across newer generations of devices, improved imaging, and greater operator expertise have collectively contributed to the increased safety and efficacy of this procedure over time. Various emerging transcatheter mitral valve repair and replacement devices are currently under investigation and may offer superior, complementary or synergistic treatment options in patients ineligible for TEER. This review provides a state-of-the-art overview regarding the diagnosis of SMR, and currently available transcatheter mitral valve interventions and describes a contemporary approach to the management of SMR.

Transcatheter Structural Heart Disease Interventions and Concomitant Left Atrial Appendage Occlusion: A State of the Art Review

Atrial fibrillation (AF) is the most common arrhythmia in patients with valvular heart disease, and it can be associated with adverse patient outcomes. However, the need for anticoagulation to counterbalance AF-associated stroke risk may further lead to suboptimal outcomes via increasing bleeding events, especially in high-risk individuals. Because the vast majority of thrombi occur in the left atrial appendage, left atrial appendage occlusion (LAAO) is an established procedure for preventing ischemic stroke in patients with AF, while limiting anticoagulation-related bleeding events. Thus, the concept of combining an index procedure for structural heart disease (SHD) with LAAO seems promising for preventing future stroke events. A combined procedure has been described in aortic stenosis (transcatheter aortic valve implantation + LAAO), mitral regurgitation (transcatheter edge-to-edge repair + LAAO), and atrial septal defects (patent foramen ovale/atrial septal defect + LAAO). Evidence shows that a combined procedure can be safely performed in a "1-stop shop" fashion, without increased rates of procedural adverse events, with the potential to limit bleeding risk and provide prophylaxis against stroke events. This review analyses indications and clinical evidence regarding the safety and efficacy of combined SHD+LAAO procedures, while also providing insights into gaps in knowledge and future directions for the evolution of this field.

Management of secondary mitral regurgitation: from drugs to devices

Severe secondary mitral regurgitation carries a poor prognosis with one in five patients dying within 12 months of diagnosis. Fortunately, there are now a number of safe and effective therapies available to improve outcomes. Here, we summarise the most up-to-date treatments. Optimal guideline-directed medical therapy is the mainstay therapy and has been shown to reduce the severity of mitral regurgitation in 40-45% of patients. Rapid medication titration protocols reduce heart failure hospitalisation and facilitate earlier referral for device therapy. The pursuit of sinus rhythm in patients with atrial fibrillation has been shown to significantly reduce mitral regurgitation severity, as has the use of cardiac resynchronisation devices in patients who meet guideline-directed criteria. Finally, we highlight the key role of mitral valve intervention, particularly transcatheter edge-to-edge repair (TEER) for management of moderate-severe mitral regurgitation in carefully selected patients with poor left ventricular systolic function, with a number needed to treat of 3.1 to reduce heart failure hospitalisation and 5.9 to reduce all-cause death. To slow the rapid accumulation of morbidity and mortality, we advocate a proactive approach with accelerated medical optimisation, followed by management of atrial fibrillation and cardiac resynchronisation therapy if indicated, then, rapid referral to the Heart Team for consideration of mitral valve intervention in patients with ongoing symptoms and at least moderate-severe mitral regurgitation. Mitral TEER has been shown to be 'reasonably cost-effective' (but not cost-saving) in the UK in selected patients, although TEER remains underused with only 6.5 procedures per million population (pmp) compared with Germany (77 pmp), Switzerland (44 pmp) and the USA (32 pmp).

Outcomes of Transcatheter Mitral Valve Repair Using the MitraClip System in Patients With Atrial Fibrillation. A Meta-Analysis

Transcatheter mitral valve repair (TMVR) with the MitraClip system is now approved for degenerative and functional mitral regurgitation (MR). Atrial fibrillation (AF) is commonly seen in MR. In our study, we perform a pooled analysis of the existing data to investigate the outcomes of MitraClip in patients with versus without AF. We conducted a systematic search of PubMed, Google Scholar, and SCOPUS databases through December, 2022 for studies comparing the outcomes of TMVR using the MitraClip in patients with preexisting AF versus those without AF. A meta-analysis was performed to investigate the primary outcomes of all-cause mortality and heart failure (HF) hospitalization. Secondary outcomes were cardiovascular mortality, in-hospital mortality, stroke, New York Heart Association class I or II at follow-up, length of hospital stay, and procedural time. A total of 10 studies (n = 24,111; AF = 12,789; no AF = 11,322) were included in the final analysis. Preexisting AF was associated with higher overall all-cause mortality (odds ratio 1.55, 95% confidence interval 1.32 to 1.83, p <0.0002) and higher overall HF hospitalization rate (odds ratio 1.3, 95% confidence interval 1.08 to 1.56, p <0.0154). There was no statistically significant difference in cardiovascular mortality, in-hospital mortality, stroke, length of hospital stay, procedural time, or New York Heart Association class I/II at follow-up comparing AF versus no AF. The presence of AF in patients who underwent TMVR with MitraClip is associated with higher all-cause mortality and HF hospitalization. This should be taken into consideration in the management of MR patients.

Implications of Atrial Fibrillation for Guideline-Directed Therapy in Patients With Heart Failure: JACC State-of-the-Art Review

Atrial fibrillation (AF) and heart failure (HF) are common cardiovascular conditions that frequently coexist. Among patients with HF, more than one-half also have AF. Both are associated with significant morbidity and mortality. Moreover, the prevalence of each is increasing globally, and this trend is expected to continue owing to an aging population and increased life expectancy. Diagnosis of AF in a patient with HF is associated with greater symptom burden, more frequent hospitalizations, and a worse prognosis. Guideline-directed medical therapy (GDMT) for HF can affect the incidence of AF. Once present, AF can influence the efficacy of some components of GDMT for HF. In this review, we discuss the effect of GDMT for HF across the spectrum of ejection fraction on prevention of AF as well as the benefit of GDMT in patients with vs without AF.

Interventional management of mitral regurgitation and sleep disordered breathing: "Catching two birds with one stone"

Sleep disordered breathing (SDB), mostly constituting of obstructive and central sleep apnea (OSA and CSA, respectively), is highly prevalent in the general population, and even more among patients with cardiovascular disease, heart failure (HF) and valvular heart disease, such as mitral regurgitation (MR). The coexistence of HF, MR and SDB is associated with worse cardiovascular outcomes and increased morbidity and mortality. Pulmonary congestion, as a result of MR, can exaggerate and worsen the clinical status and symptoms of SDB, while OSA and CSA, through various mechanisms that impair left ventricular dynamics, can promote left ventricular remodelling, mitral annulus dilatation and consequently MR. Regarding treatment, positive airway pressure devices used to ameliorate symptoms in SDB also seem to result in a reduction of MR severity, MR jet fraction and an improvement of left ventricular ejection fraction. However, surgical and transcatheter interventions for MR, and especially transcatheter edge to edge mitral valve repair (TEER), seem to also have a positive effect on SDB, by reducing OSA and CSA-related severity indexes and improving symptom control. The purpose of this review is to provide a comprehensive analysis of the common pathophysiology between SDB and MR, as well as to discuss the available evidence regarding the effect of SDB treatment on MR and the effect of mitral valve surgery or transcatheter repair on both OSA and CSA.

Heart Failure and Secondary Mitral Regurgitation: A Contemporary Review

Secondary mitral regurgitation (SMR) in patients with heart failure (HF) is associated with significant morbidity and mortality. In recent decades, SMR has received increasing scientific attention. Advances in echocardiography, computed tomography and cardiac magnetic resonance imaging have refined our ability to diagnose, quantify and characterize SMR. Concurrently, the treatment options for this high-risk patient population have continued to evolve. Guideline-directed medical therapies including beta-blockers, angiotensin receptor-neprilysin inhibitors, mineralocorticoid receptor antagonists and sodium-glucose cotransporter-2 inhibitors target the underlying cardiomyopathy, and along with diuretics to treat pulmonary congestion, remain the cornerstone of therapy. Cardiac resynchronization therapy also reduces MR, alleviates symptoms and prolongs life in selected HF patients with SMR. While data supporting surgical mitral valve repair or replacement for SMR are limited, transcatheter edge-to-edge repair (TEER) has been demonstrated to improve survival, reduce the rate of hospitalization for heart failure, and improve functional capacity and quality-of-life in select patients with SMR who remain symptomatic despite medical therapy. Emerging transcatheter mitral valve repair and replacement technologies are undergoing investigation in TEER-eligible and TEER-ineligible patients. The optimal management of HF patients with SMR requires a multidisciplinary team of cardiologists, cardiac surgeons, imaging experts, and other organ specialists to select the best treatment approaches to improve the prognosis of these high-risk patients.

Perspectives on Secondary Mitral Regurgitation in Heart Failure

PURPOSE OF THE REVIEW

This review focuses on broader perspectives of mitral regurgitation (MR) in patients with heart failure.

RECENT FINDINGS

The ratio of regurgitant volume to end-diastolic volume appears to help identify patients who may benefit from valve interventions. Secondary MR is not only attributed to geometric changes of the LV but also related to the structural changes in the mitral valve that include fibrosis of the mitral leaflets and changes in the extracellular matrix. The transition from mild to severe secondary MR can occur at different rates, from a slow LV remodeling process to a more abrupt process precipitated by an inciting event such as atrial fibrillation. Septal flash and apical rocking, two new visual markers of LV mechanical dyssynchrony, appear to be predictive of MR reduction following cardiac resynchronization therapy. Optimal guideline-directed medical therapy has been shown to decrease the severity of secondary MR effectively. A theoretical framework to characterize secondary MR as it relates to the onset of MR is proposed. Type A: Early onset of MR contemporaneous with myocardial injury. The maladaptive LV remodeling occurs in parallel with MR. Type B: LV remodeling proceeds without significant MR until the LV is moderately dilated, which coincides with or without inciting factors such as atrial fibrillation. Type C: LV remodeling proceeds after myocardial injury without significant MR until the LV is severely dilated. MR is a late manifestation of LV remodeling.

Arrythmia-Mediated Valvular Heart Disease

The aging population is rising at record pace worldwide. Along with it, a steep increase in the prevalence of atrial fibrillation and heart failure with preserved ejection fraction is to be expected. Similarly, both atrial functional mitral and tricuspid regurgitation (AFMR and AFTR) are increasingly observed in daily clinical practice. This article summarizes all current evidence regarding the epidemiology, prognosis, pathophysiology, and therapeutic options. Specific attention is addressed to discern AFMR and AFTR from their ventricular counterparts, given their different pathophysiology and therapeutic needs.

Patient phenotype profiling in heart failure with preserved ejection fraction to guide therapeutic decision making. A scientific statement of the Heart Failure Association, the European Heart Rhythm Association of the European Society of Cardiology, and the European Society of Hypertension

Heart failure with preserved ejection fraction (HFpEF) represents a highly heterogeneous clinical syndrome affected in its development and progression by many comorbidities. The left ventricular diastolic dysfunction may be a manifestation of various combinations of cardiovascular, metabolic, pulmonary, renal, and geriatric conditions. Thus, in addition to treatment with sodium-glucose cotransporter 2 inhibitors in all patients, the most effective method of improving clinical outcomes may be therapy tailored to each patient's clinical profile. To better outline a phenotype-based approach for the treatment of HFpEF, in this joint position paper, the Heart Failure Association of the European Society of Cardiology, the European Heart Rhythm Association and the European Hypertension Society, have developed an algorithm to identify the most common HFpEF phenotypes and identify the evidence-based treatment strategy for each, while taking into account the complexities of multiple comorbidities and polypharmacy.

Cerebrovascular Events After Transcatheter Edge-to-Edge Repair and Guideline-Directed Medical Therapy in the COAPT Trial

BACKGROUND

Little is known regarding the risk of cerebrovascular events (CVE) in patients with heart failure and severe secondary mitral regurgitation treated with transcatheter edge-to-edge repair (TEER).

OBJECTIVES

The study sought to examine the incidence, predictors, timing, and prognostic impact of CVE (stroke or transient ischemic attack) in the COAPT (Cardiovascular Outcomes Assessment of the Mitraclip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) trial.

METHODS

A total of 614 patients with heart failure and severe secondary mitral regurgitation were randomized to TEER plus guideline-directed medical therapy (GDMT) vs GDMT alone.

RESULTS

At 4-year follow-up, 50 CVEs occurred in 48 (7.8%) of the 614 total patients enrolled in the COAPT trial; Kaplan-Meier event rates were 12.3% in the TEER group and 10.2 in the GDMT alone group (P = 0.91). Within 30 days of randomization, CVE occurred in 2 (0.7%) patients randomized to TEER and 0% randomized to GDMT (P = 0.15). Baseline renal dysfunction and diabetes were independently associated with increased risk of CVE, while baseline anticoagulation was associated with a reduction of CVE. A significant interaction was present between treatment group and anticoagulation such that TEER compared with GDMT alone was associated with a reduced risk of CVE among patients with anticoagulation (adjusted HR: 0.24; 95% CI: 0.08-0.73) compared with an increased risk of CVE in patients without anticoagulation (adjusted HR: 2.27; 95% CI: 1.08-4.81; P_interaction = 0.001). CVE was an independent predictor of death within 30 days after the event (HR: 14.37; 95% CI: 7.61, 27.14; P < 0.0001).

CONCLUSIONS

In the COAPT trial, the 4-year rate of CVE was similar after TEER or GDMT alone. CVE was strongly associated with mortality. Whether anticoagulation is effective at reducing CVE risk after TEER warrants further study. (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients With Functional Mitral Regurgitation [The COAPT Trial] and COAPT CAS [COAPT); NCT01626079).

Association of atrial myopathy in mitral valve disease on safety outcomes in left atrial appendage closure

BACKGROUND

Patients undergoing left atrial appendage (LAA) occlusion (LAAO) are multi-morbid, including mitral valve disease (MVD) which is associated with anatomic changes of the left atrium (LA). This study aims to identify how atrial myopathy in MVD influences outcomes in LAAO.

METHODS

Atrial myopathy in MVD was defined as LA diameter > 45 mm (♀) and > 48 mm (♂) and existing MVD or history of surgical/interventional treatment. Patients were compared with controls from the prospective, multicentre LAArge registry of LAAO.

RESULTS

A total of 528 patients (52 MVD, 476 no-MVD) were included. The MVD group was significantly more likely to be older (78.2 years vs 75.9 years, p = 0.036) and female (59.6% vs 37.8%, p = 0.002). Altered LA anatomy was observed in MVD with significantly larger LA diameter (53 mm vs. 48 mm, p < 0.001) and LAA Ostia [at 135° 23.0 mm (20.5, 26.0) vs 20.0 mm (18.0, 23.0), p = 0.002]. Implant success was high with 96.2% and 97.9%, respectively, without differences in severe complications (7.7% vs 4.6%, p = 0.31). One-year mortality (17.8% vs 11.5%, p = 0.19) and a combined outcome of death, stroke, and systemic embolism (20.3% vs 12.4%, p = 0.13) were not different. Independent predictors of the combined outcome were peripheral artery disease (HR 2.41, 95% CI 1.46-3.98, p < 0.001) and chronic kidney disease (HR 3.46, 95% CI 2.02-5.93, p < 0.001) but not MVD and atrial myopathy.

CONCLUSION

Patients with MVD present with altered LA anatomy with increased LA and LAA diameter. However, procedural success and safety in LAAO are not compromised. One-year mortality is numerically higher in patients with MVD but driven by comorbidities.

Functional Mitral and Tricuspid Regurgitation across the Whole Spectrum of Left Ventricular Ejection Fraction: Recognizing the Elephant in the Room of Heart Failure

Functional mitral regurgitation (FMR) and tricuspid regurgitation (FTR) occur due to cardiac remodeling in the presence of structurally normal valve apparatus. Two main mechanisms are involved, distinguishing an atrial functional form (when annulus dilatation is predominant) and a ventricular form (when ventricular remodeling and dysfunction predominate). Both affect the prognosis of patients with heart failure (HF) across the entire spectrum of left ventricle ejection fraction (LVEF), including preserved (HFpEF), mildly reduced (HFmrEF), or reduced (HFrEF). Currently, data on the management of functional valve regurgitation in the various HF phenotypes are limited. This review summarizes the epidemiology, pathophysiology, and treatment of FMR and FTR within the different patterns of HF, as defined by LVEF.

Atrial functional mitral regurgitation: prevalence, characteristics and outcomes from the National Echo Database of Australia

AIMS

Atrial functional mitral regurgitation (AFMR) is characterised by left atrial and consequent mitral annular dilatation causing mitral regurgitation. AFMR is likely to become more common with population ageing, alongside increases in atrial fibrillation and heart failure with preserved ejection fraction; conditions causing atrial dilatation. Here, we aim to define the prevalence and characterise the patient and survival characteristics of AFMR in the National Echocardiographic Database of Australia (NEDA).

METHODS AND RESULTS

14 004 adults with moderate or severe FMR were identified from NEDA. AFMR or ventricular FMR (VFMR) was classified by LA size, LV size and LVEF. AFMR was found in 40% (n=5562) and VFMR in 60% (n=8442). Compared with VFMR, the AFMR subgroup were significantly older (mean age 78±11 years), with a higher proportion of females and of AF. Participants were followed up for a median of 65 months (IQR 36-116 months). After adjustment for age, sex, AF, and pulmonary hypertension, the prognosis for VFMR was significantly worse than for AFMR (HR 1.57, 95% CI 1.47 to 1.68 for all-cause and 1.73, 95% CI 1.60 to 1.88, p<0.001 for both). After further adjustment for LVEF, mortality rates were similar in VFMR and AFMR patients (HR 0.93, p=NS), though advancing age and pulmonary hypertension remained independently associated with prognosis.

CONCLUSIONS

AFMR is a common cause of significant functional MR that predominantly affects elderly female patients with AF. Advancing age and pulmonary hypertension independently associated with survival in FMR. Prognosis was better in AFMR compared with VFMR; however, this difference was accounted for by LV systolic impairment and not by MR severity.

Valvular Heart Disease: New Concepts in Pathophysiology and Therapeutic Approaches

This review discusses recent advancements in the field of valvular heart disease. Topics covered include recognition of the impact of atrial fibrillation on development and assessment of valvular disease, strategies for global prevention of rheumatic heart disease, understanding and management of secondary mitral regurgitation, the updated classification of bicuspid aortic valve disease, recognition of heightened cardiovascular risk associated with moderate aortic stenosis, and a growing armamentarium of transcatheter therapies.

Mitral valve transcatheter edge-to-edge repair

Mitral regurgitation (MR) is the most prevalent valvular heart disease and, when left untreated, results in reduced quality of life, heart failure, and increased mortality. Mitral valve transcatheter edge-to-edge repair (M-TEER) has matured considerably as a non-surgical treatment option since its commercial introduction in Europe in 2008. As a result of major device and interventional improvements, as well as the accumulation of experience by the interventional cardiologists, M-TEER has emerged as an important therapeutic strategy for patients with severe and symptomatic MR in the current European and American guidelines. Herein, we provide a comprehensive up-do-date overview of M-TEER. We define preprocedural patient evaluation and highlight key aspects for decision-making. We describe the currently available M-TEER systems and summarise the evidence for M-TEER in both primary mitral regurgitation (PMR) and secondary mitral regurgitation (SMR). In addition, we provide recommendations for device selection, intraprocedural imaging and guiding, M-TEER optimisation and management of recurrent MR. Finally, we provide information on major unsolved questions and "grey areas" in M-TEER.

Transcatheter edge to edge repair using the ease-of-use valve clamp system for functional mitral regurgitation: a primary report

PURPOSE

The ValveClamp system is a novel edge-to-edge mitral valve repair system designed for the ease of operation. We report the outcomes of our initial experience of treating functional mitral regurgitation (MR) with the ValveClamp system.

METHODS

The subjects of this study were patients with symptomatic functional MR despite standard medical therapy, who were treated with transapical ValveClamp implantation. The patients were divided into an atrial functional mitral regurgitation (AFMR) group and a ventricular functional mitral regurgitation (VFMR) group. Clinical and echocardiographic outcomes were evaluated at baseline and then at the 3-month follow up.

RESULTS

Twelve patients, with a median age of 71 years (range 65-78 years), were assigned to the AFMR group (n = 5) or the VFMR group (n = 7). The device implantation rate was 100%, and 10 (83.3%) patients required implantation of only one clamp. The catheter time was less than 10 min in half of the patients, the fastest time being 5 min. There were no procedure-related complications. At the 3-month follow up, all patients were free from all-cause mortality, surgery, and rehospitalization. MR improved to ≤ 2 + in all 12 patients with MR grade 3 + or 4 + at baseline, (100%) and to ≤ 1 + in 9 of these patients (75%), with a low-pressure gradient. The left atrial diameter and the left ventricular end diastolic diameter decreased significantly in both the AFMR and VFMR groups. The left ventricular eject fraction at the 3-month follow up showed a rising trend in both the AFMR and VFMR groups, whereas PASP decreased remarkably. All 12 patients with baseline NYHA functional class III/IV (100%) showed improvement of at least 1 class, and 2 of these patients (16.7%) showed improvement of at least 2 classes.

CONCLUSIONS

The ValveClamp system is simple and effective for transapical transcatheter edge to edge repair in patients with functional MR.

Derivation and Validation of a Clinical Risk Score for COAPT-Ineligible Patients Who Underwent Transcatheter Edge-to-Edge Repair

Up to half of real-world patients with secondary mitral regurgitation who underwent transcatheter edge-to-edge repair (TEER) do not meet the highly selective COAPT (Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation) criteria. No randomized trials or standardized and validated tools exist to evaluate the risk: benefit ratio of TEER in this specific population. We sought to derive and externally validate a clinical risk score to predict the risk of death or heart failure (HF) hospitalization for COAPT-ineligible patients who underwent TEER (CITE score). The study population consisted of patients with secondary mitral regurgitation having at least 1 exclusion criterion of the COAPT trial. The derivation cohort included 489 patients from the GIOTTO (GIse registry of Transcatheter treatment of Mitral Valve regurgitaTiOn) registry. Cox proportional hazards regression was used to identify predictors of 2-year death/HF hospitalization and develop a numerical risk score. The predictive performance was assessed in the derivation cohort and validated in 268 patients from the MiZüBr (Milan-Zürich-Brescia) registry. The CITE score (hemodynamic instability, left ventricular impairment, New York Heart Association class III/IV, peripheral artery disease, atrial fibrillation, brain natriuretic peptide, and hemoglobin) showed a c-index for 2-year death or HF hospitalization of 0.70 (95% confidence interval [CI] 0.67 to 0.73) in the derivation cohort, and 0.68 (95% CI 0.64 to 0.73) in the validation cohort. A cutoff of <12 points was selected to identify patients at lower risk of adverse outcomes, hazard ratio of 0.35 (95% CI 0.26 to 0.46). In conclusion, the CITE score is a simple 7-item tool for the prediction of death or HF hospitalization at 2 years after TEER in COAPT-ineligible patients. The score may support clinical decision-making by identifying those patients who, even if excluded from clinical trials, can still benefit from TEER.

Pathophysiology, Echocardiographic Diagnosis, and Treatment of Atrial Functional Mitral Regurgitation: JACC State-of-the-Art Review

The conventional view holds that functional mitral regurgitation (MR) is caused by restriction of leaflet motion resulting from displacement of the papillary muscle-bearing segments of the left ventricle. In the past decade, evidence has accrued suggesting functional MR can also be caused by left atrial enlargement. This underrecognized cause of secondary MR-atrial functional MR (AF-MR)-is mechanistically linked to annular enlargement, perturbations of annular contraction, and atriogenic leaflet tethering. AF-MR has been described in patients with atrial fibrillation and heart failure with preserved ejection fraction. Preliminary data suggest rhythm control may decrease MR severity in patients with atrial fibrillation. Additionally, several studies have reported reductions in MR and symptomatic improvement with restrictive annuloplasty and transcatheter edge-to-edge repair. This review discusses the pathophysiology, echocardiographic diagnosis, and treatment of AF-MR. AF-tricuspid regurgitation is also discussed.

Clinical Outcomes With Transcatheter Edge-to-Edge Repair in Atrial Functional MR From the EXPAND Study

BACKGROUND

Although transcatheter edge-to-edge repair (TEER) has been shown to improve clinical outcomes and improve quality of life in patients with symptomatic secondary mitral regurgitation (SMR) and left ventricular dysfunction, its effect in patients with atrial SMR (aSMR) has not been well described.

OBJECTIVES

The aim of this study was to assess the safety, echocardiographic outcomes, and clinical effectiveness of TEER for aSMR.

METHODS

Patients with aSMR in the prospective, observational, multicenter EXPAND (A Contemporary, Prospective, Multi-Center Study Evaluating Real-World Experience of Performance and Safety for the Next Generation of MitraClip Devices) study were identified by an echocardiography core laboratory. Follow-up occurred at discharge, 30 days, and 1 year. Key endpoints included mitral regurgitation (MR) severity, functional class, heart failure hospitalizations, mortality, and 30-day major adverse events.

RESULTS

Among 1,041 patients enrolled in EXPAND, 835 patients had evaluable echocardiograms at baseline. Of these, 53 patients had aSMR and 360 had ventricular SMR (vSMR). In the aSMR cohort, TEER resulted in a significant reduction in MR through 1 year (MR grade ≤2 in 100.0%), significantly increased 1-year Kansas City Cardiomyopathy Questionnaire score (+26.6 ± 30.5 points; P < 0.0001), and improved functional class from baseline, similar to the effects among patients with vSMR (MR grade ≤2 in 99.5% at 1 year, 1-year increase in Kansas City Cardiomyopathy Questionnaire score 21.23 ± 24.92 points). Major adverse events at 30 days and leaflet adverse events at 1 year were infrequent in both groups.

CONCLUSIONS

In a prospective, real-world, global registry, TEER for aSMR was associated with significant MR reduction and improvement in quality of life and functional class, similar to patients with vSMR. This suggests that TEER may provide clinical benefit in patients with atrial fibrillation with SMR in the setting of heart failure with preserved ejection fraction. (The MitraClip® EXPAND Study of the Next Generation of MitraClip® Devices; NCT03502811).

Incidence and Predictors of New-Onset Atrial Fibrillation After Transcatheter Edge-to-Edge Repair of the Mitral Valve (from the Nationwide Readmissions Database)

Patients who underwent transcatheter edge-to-edge repair (TEER) for mitral regurgitation with atrial fibrillation (AF) at baseline have higher mortality than those without AF. Data on new-onset AF (NOAF) after TEER are limited. Using the 2016 to 2018 Nationwide Readmissions Database, we identified a cohort of patients who underwent TEER and classified them into 3 groups based on AF presence during the study period. The primary end point was the incidence and timing of NOAF up to 6 months after TEER. Logistic regression modeling identified independent predictors of NOAF at readmission. Of the 6,861patients that underwent TEER, 4,134 (59.9%) had AF at baseline, and 239 (3.5%) developed NOAF. Median time-to-NOAF admission was 47 days (interquartile range 16 to 113), and 37% of patients with NOAF presented within 30 days after TEER. Patients with NOAF experienced costlier and longer index-TEER hospitalization and had more co-morbidities. Chronic kidney disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.03 to 2.20), fluid and electrolyte disorders (OR 1.59, 95% CI 1.01 to 2.52), and heart failure (OR 1.86, 95% CI 1.01 to 3.44) were identified as independent predictors of NOAF. Hypertensive complications and heart failure were the leading causes of readmission. In conclusion, those patients that developed NOAF after TEER tended to be an overall sicker group at baseline compared with the remainder of the study cohort. These data, obtained from a nationally representative cohort, highlight a particular group of patients subject to developing NOAF and their association with increased rehospitalization in the post-TEER setting. Predictors of NOAF can be screened for during TEER workup to identify patients at increased risk.

Management of Atrial Fibrillation Across the Spectrum of Heart Failure With Preserved and Reduced Ejection Fraction

Atrial fibrillation (AF) is the most common arrhythmia among patients with heart failure (HF), and HF is the most common cause of death for patients presenting with clinical AF. AF is frequently associated with pathological atrial myocardial dysfunction and remodeling, a triad that has been called atrial myopathy. AF can be the cause or consequence of clinical HF, and the directionality varies between individual patients and across the spectrum of HF. Although initial trials suggested no advantage for a systematic rhythm control strategy in HF with reduced ejection fraction, recent data suggest that select patients may benefit from attempts to maintain sinus rhythm with catheter ablation. Preliminary data also show a close relationship among AF, left atrial myopathy, mitral regurgitation, and HF with preserved ejection, with potential clinical benefits to catheter ablation therapy. The modern management of AF in HF also requires consideration of the degree of atrial myopathy and chronicity of AF, in addition to the pathogenesis and phenotype of the underlying left ventricular HF. In this review, we summarize the contemporary management of AF and provide practical guidance and areas in need of future investigation.

2021. The year in review. Structural heart interventions

Since the beginning of 2020, the corona virus (COVID-19) pandemic redefined in many ways the practice of cardiology, research and cardiology conferences. Virtual conferences replaced most major in-person venues. The number of "elective" structural heart interventions declined and clinical research endured major setbacks in regards to academic and industry-sponsored clinical trials. In this review, we attempt to provide a broad overview of the field for general and interventional cardiologists with a specific interest in structural heart interventions.

Mortality and Clinical Predictors After Percutaneous Mitral Valve Repair for Secondary Mitral Regurgitation: A Systematic Review and Meta-Regression Analysis

Background

Percutaneous mitral valve repair (PMVR) provides an available choice for patients suffering from secondary mitral regurgitation (SMR), especially those whose symptoms persist after optimal, conventional, heart-failure therapy. However, conflicting results from clinical trials have created a problem in identifying patients who will benefit the most from PMVR.

Objective

To pool mortality data and assess clinical predictors after PMVR among patients with SMR. To this end, subgroup and meta-regression analyses were additionally performed.

Methods

We searched PubMed, EMBASE, and Cochrane databases, and 13 studies were finally included for meta-analysis. Estimated mortality and 95% confidence intervals (CIs) were obtained using a random-effects proportional meta-analysis. We also carried out a meta-regression analysis to clarify the potential influence of important covariates on mortality.

Results

A total of 1,259 patients with SMR who had undergone PMVR were enrolled in our meta-analysis. The long-term estimated pooled mortality of PMVR was 19.3% (95% CI: 13.6–25.1). Meta-regression analysis showed that mortality was directly proportional to cardiac resynchronization therapy (CRT) (β = 0.009; 95% CI: 0.002–0.016; p = 0.009), an effective regurgitant orifice (ERO) (β = 0.009; 95% CI: 0.000–0.018; p = 0.047), and a mineralocorticoid receptor antagonist (MRA) use (β = −0.015; 95% CI: −0.023–−0.006; p < 0.001). Subgroup analysis indicated that patients with preexisting AF (β = −0.002; 95% CI: −0.005– −0.000; p = 0.018) were associated with decreased mortality if they received a mitral annuloplasty device. Among the edge-to-edge repair device group, a higher left ventricular (LV) ejection fraction, or lower LV end-systolic diameter, LV end-systolic volume, and LV end-diastolic volume were proportional to lower mortality.

Conclusion and Relevance

The pooled mortality of PMVR was 19.3% (95% CI: 13.6–25.1). Further meta-regression indicated that AF was associated with a better outcome in conjunction with the use of a mitral annuloplasty device, while better LV functioning predicted a better outcome after the implantation of an edge-to-edge repair device.

Atrial mitral regurgitation: Characteristics and outcomes of transcatheter mitral valve edge-to-edge repair

BACKGROUND

Mitral transcatheter edge-to-edge repair (MTEER) is an established therapeutic approach for mitral regurgitation (MR). Functional mitral regurgitation originating from atrial myopathy (A-FMR) has been described.

OBJECTIVES

We sought to assess the clinical, echocardiographic and hemodynamic considerations in A-FMR patients undergoing MTEER.

METHODS

From 2014 to 2020, patients undergoing MTEER for degenerative MR (DMR), functional MR (FMR), and mixed MR were assessed. A-FMR was defined by the presence of MR > moderate in severity; left ventricular (LV) ejection fraction (LVEF) ≥ 50%; and severe left atrial (LA) enlargement in the absence of LV dysfunction, leaflet pathology, or LV tethering. The diagnosis of A-FMR (vs. ventricular-FMR [V-FMR]) was confirmed by three independent echocardiographers. Baseline characteristics, procedural outcomes as well as clinical and echocardiographic follow-up are reported. Device success was defined as final MR grade ≤ moderate; MR reduction ≥1 grade; and final transmitral gradient <5 mmHg.

RESULTS

306 patients underwent MTEER, including DMR (62%), FMR (19%), and mixed MR (19%). FMR cases included 37 (63.8%) V-FMR and 21 (36.2%) A-FMR. Tricuspid regurgitation (≥ moderate) was higher in A-FMR (80.1%) compared to V-FMR (54%) and DMR (42%). Device success did not significantly differ between A-FMR and V-FMR (57% vs. 73%, p = 0.34) or DMR (57% vs. 64%, p = 1.0). The A-FMR cohort was less likely to achieve ≥3 grades of MR reduction compared to V-FMR (19% vs. 54%, p = 0.01) and DMR (19% vs. 49.7%, p = 0.01). Patients with V-FMR and DMR demonstrated significant reductions in mean left atrial pressure (LAP) and peak LA V-wave, though A-FMR did not (LAP -0.24 ± 4.9, p = 0.83; peak V-wave -1.76 ± 9.1, p = 0.39). In follow-up, echocardiographic and clinical outcomes were similar.

CONCLUSIONS

In patients undergoing MTEER, A-FMR represents one-third of FMR cases. A-FMR demonstrates similar procedural success but blunted acute hemodynamic responses compared with DMR and V-FMR following MTEER. Dedicated studies specifically considering A-FMR are needed to discern the optimal therapeutic approaches.

Clinical, functional and prognostic implications of severe atrial dilation in secondary mitral regurgitation

Objective

Atrial dilation is known to be a poor prognostic indicator. However, its clinical, functional and prognostic implications have not been thoroughly explored in secondary mitral regurgitation (SMR). We sought to describe the implications of severe atrial dilation (SAD) in SMR.

Methods

We included all adult patients with severe SMR due to left ventricle dysfunction (with no organic mitral valve disease) who underwent transthoracic echocardiography between January 2012 and March 2021 at our institution. The concomitant presence of severe left atrial (LA) dilation (>48 mL/m²) defined SADMR (SAD in SMR), and these patients were compared with those without SAD.

Results

A total of 2011 patients were included (mean age 70% and 41% females), with 71% having SADMR. MR severity and ejection fraction were similar between both groups. Patients with SADMR were older, less females and had more diabetes, but similar rates of atrial fibrillation. Mechanistically, they had lower A wave velocity (0.61 vs 0.72 cm/sec, p<0.001) and more impaired LA reservoir strain (9.7% vs 15.5%, p<0.001). Geometrically, SADMR had shallower leaflets’ angulations, lower tenting height, larger annuli and smaller leaflet length/annular diameter ratios (all p<0.001). They underwent fewer MV interventions, although these were associated with better outcomes (log-rank p<0.001). Over the study period, SAD was an independent predictor of mortality (HR 1.26, p=0.04).

Conclusion

SADMR is associated with specific mechanistic and functional alterations and confers a worse prognosis.

Genetically Predicted Atrial Fibrillation and Valvular Heart Disease: A Two-Sample Mendelian Randomization Study

Background

Previous studies have found atrial fibrillation (AF) is associated with valvular heart disease (VHD). However, whether there is a causal relationship between these two diseases or it is just a result of bias caused by confounding factors is uncertain. This study aims to examine the potential causal association between AF and VHD by using Mendelian randomization.

Methods

In order to examine the causal relationship between AF and VHD, we performed a two-sample Mendelian randomization study by collecting exposure and outcome data from genome-wide association study (GWAS) datasets. We utilized data from FinnGen project (FinnGen, 11,258 cases for VHD including rheumatic fever, 3,108 cases for non-rheumatic VHD, and 75,137 cases for participants) and European Bio-informatics Institute database (EBI, 55,114 cases for AF and 482,295 cases for participants). Inverse-variance weighted (IVW), MR-Egger, and weighted median approaches were performed to estimate the causal effect.

Results

The Mendelian randomization analysis indicated that AF increased the risk of VHD by all three MR methods [For VHD including rheumatic fever: IVW, odds ratio (OR) = 1.255; 95% confidence interval (CI), 1.191~1.322; p = 1.23 × 10⁻¹⁷; Weighted median, OR = 1.305, 95% CI, 1.216~1.400, p = 1.57 × 10⁻¹³; MR-Egger, OR = 1.250, 95% CI, 1.137~1.375, p = 1.69 × 10⁻⁵; For non-rheumatic VHD: IVW, OR = 1.267; 95% CI, 1.169~1.372; p = 6.73 × 10⁻⁹; Weighted median, OR = 1.400; 95% CI, 1.232~1.591; p = 2.40 × 10⁻⁷; MR-Egger, OR = 1.308; 95% CI, 1.131~1.513; p = 5.34 × 10⁻⁴]. After the one outlier SNP was removed by heterogeneity test, the results remained the same. No horizontal pleiotropic effects were observed between AF and VHD.

Conclusions

Our study provides strong evidence of a causal relationship between AF and VHD. Early intervention for AF patients may reduce the risk of developing into VHD.

The year in cardiovascular medicine 2021: heart failure and cardiomyopathies

In the year 2021, the universal definition and classification of heart failure (HF) was published that defines HF as a clinical syndrome with symptoms and/or signs caused by a cardiac abnormality and corroborated by elevated natriuretic peptide levels or objective evidence of cardiogenic congestion. This definition and the classification of HF with reduced ejection fraction (HFrEF), mildly reduced, and HF with preserved ejection fraction (HFpEF) is consistent with the 2021 ESC Guidelines on HF. Among several other new recommendations, these guidelines give a Class I indication for the use of the sodium-glucose co-transporter 2 (SGLT2) inhibitors dapagliflozin and empagliflozin in HFrEF patients. As the first evidence-based treatment for HFpEF, in the EMPEROR-Preserved trial, empagliflozin reduced the composite endpoint of cardiovascular death and HF hospitalizations. Several reports in 2021 have provided novel and detailed analyses of device and medical therapy in HF, especially regarding sacubitril/valsartan, SGLT2 inhibitors, mineralocorticoid receptor antagonists, ferric carboxymaltose, soluble guanylate cyclase activators, and cardiac myosin activators. In patients hospitalized with COVID-19, acute HF and myocardial injury is quite frequent, whereas myocarditis and long-term damage to the heart are rather uncommon.

Transcatheter edge-to-edge mitral valve repair in atrial functional mitral regurgitation: insights from the multi-center MITRA-TUNE registry

BACKGROUND

A-FMR is considered a specific sub-type of secondary MR in patients with atrial fibrillation (AF) and preserved left ventricle ejection fraction (LVEF). Aim of the study was to investigate the acute and mid-term outcomes of transcatheter edge-to-edge mitral valve repair (TMVr) with the MitraClip in atrial functional mitral regurgitation (A-FMR).

METHODS

The study included patients with A-FMR and concomitant AF who underwent to the MitraClip at 7 Italian Centers. Aim of the study was to assess the safety, efficacy and mid-term cardiovascular outcomes.

RESULTS

After reviewing 1153 patients with FMR treated with TMVr from 2009 to 2021, 87 patients (median age 81 years, 61% female) with A-FMR were identified. Technical success was achieved in 97%, 30-day device success in 83% and 30-day procedural success in 80%. All-cause death at 30-day was 5%. Estimated two-year freedom from all-cause death and cardiac death was 60% and 77%, respectively, whereas freedom from all-cause death/heart failure hospitalization was 55%. Residual MR ≤ 2+ was encountered in 89% (n = 47/53) and improvement in NYHA class I/II in 79% (n = 48/61). Post-procedural MR ≥ 2+ (HR 5.400, CI 1.371-21.268) and inter-commissural annular diameter ≥ 35 mm (HR 4.159, CI 1.057-16.363) were independent predictors of all-cause death/heart failure hospitalization during the follow-up. Positive reverse remodeling of left atrium and mitral annular dimensions occurred after TMVr during the follow-up.

CONCLUSIONS

MitraClip resulted to be a safe and effective option to treat A-FMR in elderly patients.