Underweight is associated with inferior short and long-term outcomes after MitraClip implantation: Results from the German TRAnscatheter mitral valve interventions (TRAMI) registry

Frailty and transcatheter valve intervention: A narrative review

Frailty is a common clinical syndrome that portends poor peri-procedural outcomes and increased mortality following transcatheter valve interventions. We reviewed frailty assessment tools in transcatheter intervention cohorts to recommend a pathway for preprocedural frailty assessment in patients referred for transcatheter valve procedures, and evaluated current evidence for frailty interventions and their efficacy in transcatheter intervention. We recommend the use of a frailty screening instrument to identify patients as frail, with subsequent referral for comprehensive geriatric assessment in these patients, to assist in selecting appropriate patients and then optimizing them for transcatheter valve interventions. Interventions to reduce preprocedural frailty are not well defined, however, data from limited cohort studies support exercise-based interventions to increase functional capacity and reduce frailty in parallel with preprocedural medical optimization.

Low body mass index and risk of mortality after mitral transcatheter edge-to-edge repair procedure: The "obesity paradox"

BACKGROUND

Most patients undergoing the mitral transcatheter edge-to-edge repair (TEER) technique are elderly comorbid patients. Low body mass index (BMI) < 23 kg/m2 has been identified in other elderly populations as a risk factor, but has not been studied sufficiently in mitral TEER.

AIMS

We aimed to study the impact of low BMI (23 kg/m2) on the outcome after mitral TEER.

METHODS

Patients undergoing first-time TEER for mitral regurgitation at a single tertiary center were included, with the exclusion of patients with preprocedural hemodynamic instability or missing BMI. The primary endpoint was all-cause mortality. Secondary endpoints were long-term major bleeding or admission with heart failure.

RESULTS

A total of 120 patients (mean age 76 ± 10 years, 76% men) were included in the study. Thirty-nine (31%) had low BMI. Patients with low BMI had a similar symptomatic benefit as patients with BMI ≥ 23 kg/m2 at 1 year regarding decrease in diuretics dose and decrease in New York Heart Association (NYHA) class (p > 0.05). In a multivariable Cox regression analysis, BMI as a continuous variable (hazard ratio [HR]: 0.93 [95% confidence interval, CI: 0.87-0.99], p = 0.03) and low BMI (HR: 1.99 [95% CI: 1.12-3.52], p = 0.02) were associated with the primary outcome. Low BMI was not significantly associated with major bleeding (subdistribution hazard ratio [SHR]: 2.39 [95% CI: 0.96-5.97], p = 0.06) or admission with heart failure (SHR: 1.06 [95% CI: 0.61-1.88], p = 0.83) during follow-up with univariable competing risk regression analysis.

CONCLUSION

Low BMI is a risk factor for mortality after mitral valve TEER, confirming the presence of an "obesity paradox" in this population and should receive attention in patient selection.

Impact of body mass index in patients with tricuspid regurgitation after transcatheter edge-to-edge repair

BACKGROUND

Obesity and underweight represent classical risk factors for outcome in patients treated for cardiovascular disease. This study describes the impact of different body mass index (BMI) categories on 1-year clinical outcome in patients with tricuspid regurgitation (TR) undergoing transcatheter-edge-to-edge repair (TEER).

METHODS

We analyzed 211 consecutive patients (age 78.3 ± 7.2 years, 55.5% female, median EuroSCORE II 9.6 ± 6.7) with tricuspid regurgitation undergoing TEER from June 2015 until May 2021. Patients were prospectively enrolled in our single center registry and were retrospectively analyzed. Patients were stratified according to body mass index (BMI) into 4 groups: BMI < 20 kg/m2 (underweight), BMI 20.0 to < 25.0 kg/m2 (normal weight), BMI 25.0 to > 30.0 kg/m2 (overweight) and BMI ≥ 30 kg/m2 (obese).

RESULTS

Kaplan-Meier survival curves demonstrated inferior survival for underweight and obese patients, but comparable outcomes for normal and overweight patients (global log rank test, p < 0.01). Cardiovascular death was significantly higher in underweight patients compared to the other groups (24.1% vs. 7.0% vs. 6.3% vs. 6.4%; p < 0.01). Over all, there were comparable rates of bleeding, stroke and myocardial infarction. Multivariable Cox regression analysis (adjusted for age, gender, coronary artery disease, chronic obstructive pulmonary disease, tricuspid annular plane systolic excursion, left-ventricular ejection fraction) confirmed underweight (HR 3.88; 95% CI 1.64-7.66; p < 0.01) and obesity (HR 3.24; 95% CI 1.37-9.16; p < 0.01) as independent risk factors for 1-year all-cause mortality.

CONCLUSIONS

Compared to normal weight and overweight patients, obesity and underweight patients undergoing TEER display significant higher 1-year all-cause mortality.

A novel interpretative tool for early prediction of low cardiac output syndrome after valve surgery: online machine learning models

OBJECTIVE

Low cardiac output syndrome (LCOS) is a severe complication after valve surgery, with no uniform standard for early identification. We developed interpretative machine learning (ML) models for predicting LCOS risk preoperatively and 0.5 h postoperatively for intervention in advance.

METHODS

A total of 2218 patients undergoing valve surgery from June 2019 to Dec 2021 were finally enrolled to construct preoperative and postoperative models. Logistic regression, support vector machine (SVM), random forest classifier, extreme gradient boosting, and deep neural network were executed for model construction, and the performance of models was evaluated by area under the curve (AUC) of the receiver operating characteristic and calibration curves. Our models were interpreted through SHapley Additive exPlanations, and presented as an online tool to improve clinical operability.

RESULTS

The SVM algorithm was chosen for modeling due to better AUC and calibration capability. The AUCs of the preoperative and postoperative models were 0.786 (95% CI 0.729-0.843) and 0.863 (95% CI 0.824-0.902), and the Brier scores were 0.123 and 0.107. Our models have higher timeliness and interpretability, and wider coverage than the vasoactive-inotropic score, and the AUC of the postoperative model was significantly higher. Our preoperative and postoperative models are available online at http://njfh-yxb.com.cn:2022/lcos.

CONCLUSIONS

The first interpretable ML tool with two prediction periods for online early prediction of LCOS risk after valve surgery was successfully built in this study, in which the SVM model has the best performance, reserving enough time for early precise intervention in critical care.

Preprocedural Controlling Nutritional Status Score as a Predictor of Mortality in Patients Undergoing Transcatheter Mitral Valve Repair - A Single Center Experience in Japan

Background: A high score for controlling nutritional status (CONUT) due to poor nutritional status has been associated with adverse outcomes in patients with chronic heart failure. However, because little is known about the effect of CONUT score on mortality rates after transcatheter mitral valve repair, we evaluated nutrition screening tools for prognosis prediction in patients undergoing transcatheter mitral valve repair using the MitraClipTM system. Methods and Results: We retrospectively analyzed 148 patients with severe mitral regurgitation (MR) who underwent MitraClipTM implantation between April 2018 and April 2021. The preprocedural CONUT scores were assessed at the time of hospitalization, the primary outcome was all-cause death, and the analysis was of the mortality and incidence rates of cardiac events 1 year post-operation. Functional MR was of ischemic origin in the majority of patients (69.6%), with a mean left ventricular ejection fraction of 48.9±15.8%. Kaplan-Meier curves indicated that all-cause death was significantly worse in the high-CONUT score group than in the low-CONUT score group. Cox hazard analysis showed a significant association between all-cause death and CONUT score, as well as MitraScore. Conclusions: Preprocedural CONUT score, as well as MitraScore, in patients undergoing transcatheter edge-to-edge mitral valve repair may predict an increased risk of all-cause death. This knowledge should allow the heart team to accurately assess the clinical implications and prognostic benefits of the procedure in individual patients.

The evolution of technical prerequisites and local boundary conditions for optimization of mitral valve interventions-Emphasis on skills development and institutional risk performance

This viewpoint report describes how the evolution of transcatheter mitral valve intervention (TMVI) is influenced by lessons learned from three evolutionary tracks: (1) the development of treatment from mitral valve surgery (MVS) to transcutaneous procedures; (2) the evolution of biomedical engineering for research and development resulting in predictable and safe clinical use; (3) the adaptation to local conditions, impact of transcatheter aortic valve replacement (TAVR) experience and creation of infrastructure for skills development and risk management. Thanks to developments in computer science and biostatistics, an increasing number of reports regarding clinical safety and effectiveness is generated. A full toolbox of techniques, devices and support technology is now available, especially in surgery. There is no doubt that the injury associated with a minimally invasive access reduces perioperative risks, but it may affect the effectiveness of the treatment due to incomplete correction. Based on literature, solutions and performance standards are formulated with an emphasis in technology and positive outcome. Despite references to Heart Team decision making, boundary conditions such as hospital infrastructure, caseload, skills training and perioperative risk management remain underexposed. The role of Biomedical Engineering is exclusively defined by the Research and Development (R&D) cycle including the impact of human factor engineering (HFE). Feasibility studies generate estimations of strengths and safety limitations. Usability testing reveals user friendliness and safety margins of clinical use. Apart from a certification requirement, this information should have an impact on the definition of necessary skills levels and consequent required training. Physicians Preference Testing (PPT) and use of a biosimulator are recommended. The example of the interaction between two Amsterdam heart centers describes the evolution of a professional ecosystem that can facilitate innovation. Adaptation to local conditions in terms of infrastructure, referrals and reimbursement, appears essential for the evolution of a complete mitral valve disease management program. Efficacy of institutional risk management performance (IRMP) and sufficient team skills should be embedded in an appropriate infrastructure that enables scale and offers complete and safe solutions for mitral valve disease. The longstanding evolution of mitral valve therapies is the result of working devices embedded in an ecosystem focused on developing skills and effective risk management actions.

Sex-specific impact of anthropometric parameters on outcomes after transcatheter edge-to-edge repair for secondary mitral regurgitation

BACKGROUND

Body surface area (BSA) has been reported to be the stronger predictor for prognosis than body mass index in heart failure (HF) patients. The sex-specific association of BSA with mortality has been unclear.

METHODS

EuroSMR, a European multicenter registry, included patients who underwent edge-to-edge repair (TEER) for secondary mitral regurgitation (SMR). The outcome was two-year all-cause mortality.

RESULTS

The present cohort included 1594 HF patients (age, 74 ± 10 years; male, 66%). Association of calculated BSA with two-year all-cause mortality was evaluated. Patients were classified into three BSA groups: the lowest 10% (S), the highest 10% (L), and intermediate between S and L (M). Mean BSA was 1.87 ± 0.21 m² (male, 1.94 ± 0.18 m²; female, 1.73 ± 0.18 m²). The association of BSA with the endpoint in females showed a U-shaped curve, indicating worse prognosis for both S and L. The association in males followed a linear regression, demonstrating better prognosis for L. Hazard ratio (HR) of L to S in males was 0.43 (95% confidence interval [CI], 0.25-0.74; p = 0.002), whereas HR of L to M in females was 1.76 (95% CI, 1.11-2.78; p = 0.016) (p for interaction = 0.003).

CONCLUSIONS

Sex-specific association patterns demonstrate the complex influence of anthropomorphic factors in HF patients scheduled for TEER. Further investigation beyond simple evaluation of weight and height is needed for better comprehension of the obesity paradox and better prediction of the results of transcatheter therapy in HF patients.

Prognostic Impact of Nutritional Status After Transcatheter Edge-to-Edge Mitral Valve Repair: The MIVNUT Registry

Background Malnutrition is associated with poor prognosis in several cardiovascular diseases. However, its prognostic impact in patients undergoing transcatheter edge-to-edge mitral valve repair (TEER) is not well known. This study sought to assess the prevalence, clinical associations, and prognostic consequences of malnutrition in patients undergoing TEER. Methods and Results A total of 892 patients undergoing TEER from the international MIVNUT (Mitral Valve Repair and Nutritional Status) registry were studied. Malnutrition status was assessed with the Controlling Nutritional Status score. The association of nutritional status with mortality was analyzed with multivariable Cox regression models, whereas the association with heart failure admission was assessed by Fine-Gray models, with death as a competing risk. According to the Controlling Nutritional Status score, 74.4% of patients with TEER had any degree of malnutrition at the time of TEER (75.1% in patients with body mass index <25 kg/m², 72.1% in those with body mass index ≥25 kg/m²). However, only 20% had moderate-severe malnutrition. TEER was successful in most of patients (94.2%). During a median follow-up of 1.6 years (interquartile range, 0.6-3.0), 267 (29.9%) patients died and 256 patients (28.7%) were admitted for heart failure after TEER. Compared with normal nutritional status moderate-severe malnutrition resulted a strong predictor of mortality (adjusted hazard ratio [HR], 2.1 [95% CI, 1.1-2.4]; P<0.001) and heart failure admission (adjusted subdistribution HR, 1.6 [95% CI, 1.1-2.4]; P=0.015). Conclusions Malnutrition is common among patients submitted to TEER, and moderate-severe malnutrition is strongly associated with increased mortality and heart failure readmission. Assessment of nutritional status in these patients may help to improve risk stratification.

Heart valve surgery and the obesity paradox: A systematic review

Obesity has been associated with increased incidence of comorbidities and shorter life expectancy, and it has generally been assumed that patients with obesity should have inferior outcomes after surgery. Previous literature has often demonstrated equivalent or even improved rates of mortality after cardiac surgery when compared to their lower-weight counterparts, coined the obesity paradox. Herein, we aim to review the literature investigating the impact of obesity on surgical valve interventions. PubMed and Embase were systematically searched for articles published from 1 January 2000 to 15 October 2021. A total of 1315 articles comparing differences in outcomes between patients of varying body mass index (BMI) undergoing valve interventions were reviewed and 25 were included in this study. Patients with higher BMI demonstrated equivalent or reduced rates of postoperative myocardial infarction, stroke, reoperation rates, acute kidney injury, dialysis and bleeding. Two studies identified increased rates of deep sternal wound infection in patients with higher BMI, although the majority of studies found no significant difference in deep sternal wound infection rates. The obesity paradox has described counterintuitive outcomes predominantly in coronary artery bypass grafting and transcatheter aortic valve replacement. Recent literature has identified similar trends in other heart valve interventions. While the obesity paradox has been well characterized, its causes are yet to be identified. Further study is essential in order to identify the causes of the obesity paradox so patients of all body sizes can receive optimal care.

Underweight Is Associated with Poor Prognosis in Heart Failure with Preserved Ejection Fraction

The obesity paradox states higher body mass index (BMI) is associated with better outcomes than normal weight in patients with heart failure with preserved ejection fraction (HFpEF). However, underweight was defined by BMI < 18.5 kg/m², and results have been inconclusive, in part due to small number of participants. The number of underweight patients with HFpEF is higher in Asian than in Western countries. In this study, we aim to determine the prognostic impact of underweight in patients with HFpEF in Asian population.We enrolled 846 consecutive patients from the PURSUIT-HFpEF registry. We then divided them into three groups by BMI, namely, underweight (BMI < 18.5 kg/m²), normal weight (18.5 ≤ BMI < 23), and overweight (23 ≤ BMI). The underweight group consisted of 187 patients (22%). Over a mean follow-up of 407 days, 105 deaths were reported as all-cause mortality. On multivariable Cox analysis, the underweight group was determined to be significantly associated with higher risk of all-cause mortality than the normal and overweight groups (Hazard ratios [HR]: 2.33; 95% confidence intervals [CI]: 1.45-3.75, P < 0.001; HR: 3.54; 95% CI: 1.99-6.29, P < 0.001, respectively), after adjustment for age, sex, vital signs, and comorbidities.Underweight is a useful predictor of poor prognosis in patients with HFpEF in Asian population.

Underweight but not overweight is associated with excess mortality in septic ICU patients

Background

Higher survival has been shown for overweight septic patients compared with normal or underweight patients in the past. This study aimed at investigating the management and outcome of septic ICU patients in different body mass index (BMI) categories in a large multicenter database.

Methods

In total, 16,612 patients of the eICU collaborative research database were included. Baseline characteristics and data on organ support were documented. Multilevel logistic regression analysis was performed to fit three sequential regression models for the binary primary outcome (ICU mortality) to evaluate the impact of the BMI categories: underweight (<18.5 kg/m²), normal weight (18.5 to < 25 kg/m²), overweight (25 to < 30 kg/m²) and obesity (≥ 30 kg/m²). Data were adjusted for patient level characteristics (model 2) as well as management strategies (model 3).

Results

Management strategies were similar across BMI categories. Underweight patients evidenced higher rates of ICU mortality. This finding persisted after adjusting in model 2 (aOR 1.54, 95% CI 1.15–2.06; p = 0.004) and model 3 (aOR 1.57, 95%CI 1.16–2.12; p = 0.003). No differences were found regarding ICU mortality between normal and overweight patients (aOR 0.93, 95%CI 0.81–1.06; p = 0.29). Obese patients evidenced a lower risk of ICU mortality compared to normal weight, a finding which persisted across all models (model 2: aOR 0.83, 95%CI 0.69–0.99; p = 0.04; model 3: aOR 0.82, 95%CI 0.68–0.98; p = 0.03). The protective effect of obesity and the negative effect of underweight were significant in individuals > 65 years only.

Conclusion

In this cohort, underweight was associated with a worse outcome, whereas obese patients evidenced lower mortality. Our analysis thus supports the thesis of the obesity paradox.

Transcatheter mitral valve repair and replacement: the next frontier of transcatheter valve intervention

PURPOSE OF REVIEW

We summarize the recent developments in transcatheter mitral valve repair (TMVr) and replacement (TMVR), discuss determinants of MitraClip outcomes in various mitral regurgitation causes, and highlight newly emerging devices and randomized trials.

RECENT FINDINGS

The discordant results published in the two recent randomized trials for MitraClip, the COAPT and the MITRA-FR trial have led to the emergence of a new conceptual framework such as the proportionate versus disproportionate mitral regurgitation and hemodynamics assessment tools like the real-time continuous left atrial pressure monitoring. Learning curve and volume-outcome analyses and studies examining the MitraClip usage in patients with degenerative mitral regurgitation are recent developments that have influenced MitraClip regulation and coverage. Several trials for TMVr devices that take an alternative approach to the edge-to-edge repair are underway and advancements in the TMVR technologies are continuing to progress to fill the unmet needs of treating high surgical risk patients whose complex valve anatomy make TMVr unfeasible.

SUMMARY

Evidence supports careful analysis of the valve area and left ventricular function in addition to the left atrial hemodynamics will improve the MitraClip outcome. Operator experience plays a greater effect when achieving excellent results with 1+ or less residual mitral regurgitation whereas surgical MVr volume did not influence TMVr outcome. Interventions on the complex primary mitral regurgitation remain under the surgical domain, but MITRA high risk (HR) and REPAIR mitral regurgitation trials are underway to evaluate the role of MitraClip in high to intermediate surgical risk patients with primary mitral regurgitation. Despite the slow developments in TMVR, the results of the early trials of its devices are promising.

Predictive Value of Body Mass Index in Minimally Invasive Mitral Valve Surgery

BACKGROUND

 With this study we aimed to analyze if the separate consideration of body mass index (BMI) could provide any superior predictive values compared with the established risk scores in isolated minimally invasive mitral valve surgery (MIMVS). This might facilitate future therapeutic decision-making, e.g., regarding the question surgery versus transcatheter mitral valve repair (TMVr).

METHODS

 We assessed the relevance of BMI in non-underweight patients who underwent isolated MIMVS. The risk predictive potential of BMI for mortality and several postoperative adverse events was assessed in 429 consecutive patients. This predictive potential was compared with that of European System for Cardiac Outcome Risk Evaluation II (EuroSCORE II) and the Society of Thoracic Surgeons score (STS score) using a comparative receiver operating characteristic curve analysis.

RESULTS

 BMI was a significant numeric predictor of wound healing disorders (p = 0.001) and proved to be significantly superior in case of this postoperative adverse event compared with the EuroSCORE II (p = 0.040) and STS score (p = 0.015). Except for this, the predictive potential of BMI was significantly inferior compared with that of the EuroSCORE II and STS score for several end points, including 30-day (p = 0.029 and p = 0.006) and 1-year (p = 0.012 and p = 0.001) mortality.

CONCLUSION

 Therefore, we suggest that, in the course of decision-making regarding the right treatment modality for non-underweight patients with isolated mitral valve regurgitation, the sole factor of BMI should not be given a predominant weight.