Guide to functional mitral regurgitation: a contemporary review

Vena contracta area measurement by three-dimensional echocardiography for assessing mitral regurgitation severity using a novel, fast, and reliable method

BACKGROUND

Echocardiography is the standard tool for the evaluation of mitral regurgitation (MR). Although Two-dimensional echocardiography is the most recommended tool, it has some limitations. Three-dimensional echocardiography (3DE) is suggested to overcome these limitations, however, it is more time-consuming. Introducing a simplified and accurate 3-D method could be helpful in this regard.

METHODS

Patients diagnosed with significant MR who were referred to Shahid Madani heart center, Tabriz, Iran for evaluation of MR severity were entered in this study. Patients with prior MR surgery, poor image quality, and without self-consent for participation in the study were excluded. Two-dimensional transthoracic echocardiography (TTE) and 3D transesophageal echocardiography (TEE) were performed in all patients. MR severity was compared between these two methods and between direct planimetry (DP) of the vena contracta area (VCA) and 3D directed multiplanar reconstruction (MPR).

RESULTS

A total of 53 patients were studied. Thirty-six (69.7%) of the patients were female. The mean age of patients was 66.21 ± 11.91 years. 3DVCA using DP was significantly correlated with the 2D method in terms of MR severity (p = 0.006). There was a significant correlation between the results of 3DE DP and 2DE magnetic resonance voiding cystography (MRVC) diameter (r = 0.503 and p = 0.0001). A significant correlation was also found between the result of DP and MPR-derived VCA using 3D (r = 0.97 and p = 0.0001).

CONCLUSION

TEE is an invaluable method to decide the severity and mechanism of patients with MR, especially if TTE does not give adequate information. The method proposed in this study for evaluation of MR severity and mechanism using 3D TEE could be a helpful option, especially in the above-mentioned conditions. In this study, 3D direct planimetry had an acceptable correlation with 2DE MRVC and also with 3D MPR-derived VCA.

Transcatheter Edge-to-Edge Repair Versus Annuloplasty in Functional Mitral Valve Regurgitation: A Comparison of Cardiovascular Outcomes

Background

The EVEREST trials established the MitraClip as a viable alternative to surgery in treating functional mitral valve regurgitation (FMVR). The MitraClip G4 offers a less invasive way of managing severe FMVR. We sought to compare in-patient mortality and cardiovascular complications in patients with heart failure with reduced ejection fraction (HFrEF) who developed severe FMVR requiring treatment with MitraClip G4 versus annuloplasty. Comparisons of outcomes to previous iterations of the MitraClip were included in the analysis.

Methods

Using the National Inpatient Sample, we included adult patients with FMVR and HFrEF between 2016 and 2020 who underwent percutaneous repair or annuloplasty. MitraClip G4 use was assumed for MitraClip performed in the third quarter of 2019 and afterward. To avoid overlap between the G4 and previous iterations, MitraClip data from 2019 were excluded. Mortality, stroke, and other complications were assessed. Survey-weighted logistic regression was used to adjust for selection bias in the treatment received based on age and comorbidities. The weighted analysis included 19,500 patients receiving either MitraClip G4 or annuloplasty.

Results

The MitraClip group was associated with a decreased risk of in-hospital mortality (odds ratio (OR): 0.38, confidence interval (CI): 0.18 - 0.77), ischemic stroke (OR: 0.29, CI: 0.13 - 0.61), and myocardial infarction (OR: 0.15, CI: 0.08 - 0.28). The MitraClip G4 cohort did not outperform earlier clip versions in reducing complications.

Conclusions

The MitraClip G4 was associated with lower in-hospital mortality and cardiovascular complications than annuloplasty but had outcomes similar to earlier clip versions. Additional studies comparing percutaneous therapies and surgical interventions are necessary to determine optimal treatment strategies for patients with FMVR.

Predicting One-Year Mortality after Discharge Using Acute Heart Failure Score (AHFS)

Background: Acute heart failure (AHF) represents a leading cause of unscheduled hospital stays, frequent rehospitalisations, and mortality worldwide. The aim of our study was to develop a bedside prognostic tool, a multivariable predictive risk score, that is useful in daily practice, thus providing an early prognostic evaluation at admission and an accurate risk stratification after discharge in patients with AHF. Methods: This study is a subanalysis of the STADE HF study, which is a single-centre, prospective, randomised controlled trial enrolling 123 patients admitted to hospital for AHF. Here, 117 patients were included in the analysis, due to data exhaustivity. Regression analysis was performed to determine predictive variables for one-year mortality and/or rehospitalisation after discharge. Results: During the first year after discharge, 23 patients died. After modellisation, the variables considered to be of prognostic relevance in terms of mortality were (1) non-ischaemic aetiology of HF, (2) elevated creatinine levels at admission, (3) moderate/severe mitral regurgitation, and (4) prior HF hospitalisation. We designed a linear model based on these four independent predictive variables, and it showed a good ability to score and predict patient mortality with an AUC of 0.84 (95%CI: 0.76-0.92), thus denoting a high discriminative ability. A risk score equation was developed. During the first year after discharge, we observed as well that 41 patients died or were rehospitalised; hence, while searching for a model that could predict worsening health conditions (i.e., death and/or rehospitalisation), only two predictive variables were identified: non-ischaemic HF aetiology and previous HF hospitalisation (also included in the one-year mortality model). This second modellisation showed a more discrete discriminative ability with an AUC of 0.67 (95% C.I. 0.59-0.77). Conclusions: The proposed risk score and model, based on readily available predictive variables, are promising and useful tools to assess, respectively, the one-year mortality risk and the one-year mortality and/or rehospitalisations in patients hospitalised for AHF and to assist clinicians in the management of patients with HF aiming at improving their prognosis.

Combined Significant Aortic Stenosis and Mitral Regurgitation: Challenges in Timing and Type of Intervention

In this narrative review, we aim to summarize the literature surrounding the assessment and management of the common, yet understudied combination of aortic stenosis (AS) and mitral regurgitation (MR), the components of which are complexly inter-related and interdependent from diagnostic, prognostic, and therapeutic perspectives. The hemodynamic interdependency of AS and MR confounds the assessment of the severity of each valve disease, thus underscoring the importance of a multimodal approach integrating valvular and extravalvular indicators of severity. A large body of literature suggests that baseline MR is associated with reduced survival post aortic valve (AV) intervention and that regression of MR post-AV intervention confers a mortality benefit. Functional MR is more likely to regress after AV intervention than primary MR. The respective natural courses of the 2 valve diseases are not synchronized; therefore, significant AS and MR at or above the respective threshold for intervention might not coincide. Surgery is primarily a 1-stop-shop procedure because of a considerable perioperative risk of repeat interventions, whereas transcatheter treatment modalities allow for a more tailored timing of intervention with reassessment of concomitant MR after AV replacement and a potential staged intervention in the absence of MR regression. In summary, AS and MR, when combined, are interlaced into a complex hemodynamic, diagnostic, and prognostic synergy, with important therapeutic implications. Contemporary approaches should consider stepwise intervention by exploiting the advantage of transcatheter options. However, evidence is needed to demonstrate the efficacy of different timing and therapeutic options.

Unique Aspects of Women's Valvular Heart Diseases: Impact for Diagnosis and Treatment

Valvular heart diseases (VHDs) are a major cause of cardiovascular morbidity and mortality worldwide. As degenerative and functional mechanisms represent the main etiologies in high-income countries are degenerative and functional, while in low income countries etiologie is mostly rheumatic. Although therapeutic options have evolved considerably in recent years, women are consistently diagnosed at later stages of their disease, are delayed in receiving surgical referrals, and exhibit worse postoperative outcomes, compared to men. This difference is a result of the historical underrepresentation of women in studies from which current guidelines were developed. However, in recent years, important research, including more female patients, has been conducted and has highlighted substantial sex-specific differences in the etiology, diagnosis, and treatment of VHDs. Systematic consideration of these sex-specific differences in VHD patients is crucial for providing equitable healthcare and optimizing clinical outcomes in both female and male patients. Hence, this review aims to explore implications of sex-specific particularities for diagnosis, treatment options, and outcomes in women with VHDs.

The Characteristics and Outcomes of Nonhospitalized Patients With Heart Failure in Saudi Arabia: A Contemporary Single-Center Study

Background Contemporary data on patients with heart failure (HF) in Saudi Arabia is limited. Methods This was a retrospective study of patients who were followed in the HF Clinic at our center after January 1, 2022. The study end date was August 31, 2023. Patients who were alive and followed for <6 months were excluded. We reported the clinical characteristics, utilization of established therapies for HF, proportion of potential candidates for ancillary HF treatments, and rates of HF events and mortality. Results A total of 202 patients met the study criteria. The mean age was 56.0 ± 15.2 years. The median follow-up from the initial visit to the study end date was 47 months (interquartile range {IQR}: 29-58 months). Coronary artery disease (CAD) was the cause of HF in 85 (42%) patients. At their latest visit, 103 (51%) patients had diabetes, 82 (41%) were obese, and 134 (66%) received quadruple therapy. Iron deficiency was present in 143 (71%) patients during follow-up. At their latest visit, moderate-to-severe or severe functional mitral regurgitation (MR) and hyperkalemia were present in 15 (7%) and 20 (10%) patients, respectively. The combined annual rate of HF hospitalization and emergency visits for HF was 20%. At least one hospitalization for HF within a year before the study end date occurred in 19 (9%) patients. The annual all-cause mortality was 1.8%. Conclusion This contemporary cohort of outpatients with HF was relatively young and had a high prevalence of diabetes, obesity, and iron deficiency. An estimate of potential candidates for iron replacement, transcatheter repair of the mitral valve, novel potassium binders, and the implantation of the pulmonary artery pressure monitor was among the first reported regionally. All-cause mortality was low, yet the burden of HF-related events was significant.

Computational Modeling of the Subject-Specific Effects of Annuloplasty Ring Sizing on the Mitral Valve to Repair Functional Mitral Regurgitation

Surgical repair of functional mitral regurgitation (FMR) that occurs in nearly 60% of heart failure (HF) patients is currently performed with undersizing mitral annuloplasty (UMA), which lacks short- and long-term durability. Heterogeneity in valve geometry makes tailoring this repair to each patient challenging, and predictive models that can help with planning this surgery are lacking. In this study, we present a 3D echo-derived computational model, to enable subject-specific, pre-surgical planning of the repair. Three computational models of the mitral valve were created from 3D echo data obtained in three pigs with HF and FMR. An annuloplasty ring model in seven sizes was created, each ring was deployed, and post-repair valve closure was simulated. The results indicate that large annuloplasty rings (> 32 mm) were not effective in eliminating regurgitant gaps nor in restoring leaflet coaptation or reducing leaflet stresses and chordal tension. Smaller rings (≤ 32 mm) restored better systolic valve closure in all investigated cases,but excessive valve tethering and restricted motion of the leaflets were still present. This computational study demonstrates that for effective correction of FMR, the extent of annular reduction differs between subjects, and overly reducing the annulus has deleterious effects on the valve.