Generic, Simple Risk Stratification Model for Heart Valve Surgery

Vasoactive-ventilation-renal (VVR) score: A potential tool for predicting early postoperative outcomes in adult mitral valve surgery

Background and Aims

Vasoactive-ventilation-renal (VVR) score has been validated in predicting postoperative outcomes in pediatric cardiac surgery. The aim was to evaluate its potential in predicting early postoperative outcomes in adult patients undergoing mitral valve surgery.

Material and Methods

A single-center prospective observational study involved 100 patients undergoing mitral valve surgery. We evaluated preoperative variables (Ambler score), VVR, and vasoactive-inotropic score (VIS) on admission to the intensive care unit (ICU) and then at 12, 24, and 48 hrs postoperatively. Outcomes assessed were length of stay in ICU (LOS-ICU), length of hospital stay (LOHS), and mortality. The data were analyzed using multivariable logistic regression model, receiver operating characteristic (ROC) curves, and areas under curve (AUC).

Conclusion

Our study showed the potential utility of the VVR score as a powerful tool for predicting early outcomes after mitral valve surgery, with VVR at 48 hrs having superior predictive capability.

Penalized Regression Methods With Modified Cross-Validation and Bootstrap Tuning Produce Better Prediction Models

Risk prediction models fitted using maximum likelihood estimation (MLE) are often overfitted resulting in predictions that are too extreme and a calibration slope (CS) less than 1. Penalized methods, such as Ridge and Lasso, have been suggested as a solution to this problem as they tend to shrink regression coefficients toward zero, resulting in predictions closer to the average. The amount of shrinkage is regulated by a tuning parameter,λ , $\lambda ,$ commonly selected via cross-validation ("standard tuning"). Though penalized methods have been found to improve calibration on average, they often over-shrink and exhibit large variability in the selected λ $\lambda $ and hence the CS. This is a problem, particularly for small sample sizes, but also when using sample sizes recommended to control overfitting. We consider whether these problems are partly due to selecting λ $\lambda $ using cross-validation with "training" datasets of reduced size compared to the original development sample, resulting in an over-estimation of λ $\lambda $ and, hence, excessive shrinkage. We propose a modified cross-validation tuning method ("modified tuning"), which estimates λ $\lambda $ from a pseudo-development dataset obtained via bootstrapping from the original dataset, albeit of larger size, such that the resulting cross-validation training datasets are of the same size as the original dataset. Modified tuning can be easily implemented in standard software and is closely related to bootstrap selection of the tuning parameter ("bootstrap tuning"). We evaluated modified and bootstrap tuning for Ridge and Lasso in simulated and real data using recommended sample sizes, and sizes slightly lower and higher. They substantially improved the selection of λ $\lambda $ , resulting in improved CS compared to the standard tuning method. They also improved predictions compared to MLE.

Prevalence and impact of diabetes in patients with valvular heart disease

This study aimed to investigate the prevalence of diabetes in valvular heart disease (VHD), as well as the relationship of diabetes with severity of valvular lesions and clinical outcome. A total of 11,862 patients with significant (≥moderate) VHD from the China Valvular Heart Disease study were included in the analysis. The primary outcome was the composite of all-cause death, hospitalization for heart failure, and myocardial infarction during two-year follow-up. The prevalence of diabetes was 14.5% (1,721/11,862) in VHD. After adjusting for patients' demographics, diabetes was associated with a significantly lower risk of severe valvular lesion in aortic regurgitation and mitral regurgitation (MR). In multivariable analysis, diabetes was identified as an independent predictor of two-year outcome in patients with MR (hazard ratio: 1.345, 95% confidence interval: 1.069-1.692, p = 0.011). More efforts should be made to enhance our understanding and improve outcomes of concomitant VHD and diabetes.

Meta-Analysis Global Group in Chronic Heart Failure score for the prediction of mortality in valvular heart disease

AIMS

Valvular heart disease (VHD) is one of the leading causes of heart failure. Clinically significant VHD can induce different patterns of cardiac remodelling, and risk stratification is challenging in patients with various degrees of cardiac dysfunction. The study aimed to investigate the prognostic implications of Meta-Analysis Global Group in Chronic Heart Failure (MAGGIC) score in patients with VHD.

METHODS AND RESULTS

This study used data from the China Valvular Heart Disease (China-VHD) registry, which was a multicentre, prospective, observational cohort study for patients with significant (at least moderate) VHD. In total, 10 446 patients with moderate or greater VHD from the China-VHD study were included in the present analysis. The primary outcome of interest was all-cause mortality within 2 years. Among 10 446 patients with VHD, the mean age was 61.98 ± 13.47 years, and 5819 (55.7%) were male. During 2 years of follow-up, 895 (8.6%) patients died. The MAGGIC score was monotonically and independently associated with mortality in both total cohort [adjusted hazard ratio: 1.095, 95% confidence interval (CI): 1.084-1.107, P < 0.001] and most types of VHD (aortic regurgitation, mitral stenosis, mitral regurgitation, tricuspid regurgitation, mixed aortic stenosis and aortic regurgitation, and multiple VHD). The score was also an independent prognostic factor in patients with or without symptoms or preserved left ventricular ejection fraction (LVEF) and exhibited both satisfactory discrimination and calibration properties in predicting mortality. The prognostic value of MAGGIC score was robust in most quartiles of N-terminal pro-brain natriuretic peptide level, with no significant interaction observed (Pinteraction  = 0.498). Compared with the EuroSCORE II, the MAGGIC score achieved significantly better predictive performance in overall population [C index: 0.769 vs. 0.727; net reclassification improvement index (95% CI): 0.354 (0.313-0.396), P < 0.001; integrated discrimination improvement index (95% CI): 0.069 (0.052-0.085), P < 0.001] and in subgroups of patients divided by therapeutic strategy, LVEF, symptomatic status, stage of VHD, and aetiology of VHD.

CONCLUSIONS

The MAGGIC score is a reliable prognostic factor across the range of cardiac dysfunction in VHD and may assist in risk stratification and guide clinical decision-making.

A systematic review and meta-analysis on outcomes of valvular heart surgery in Africa

INTRODUCTION

The prevalence of valvular heart diseases remain considerably high in Africa, largely but not solely due to rheumatic heart disease. Valvular heart surgeries have emerged as the cornerstone in their management. While several studies have reported data on outcomes following heart valve surgery in many developed countries, there is a staggering paucity of data and evidence reporting the outcomes in the Africa population. The aim of this study is to report the perioperative outcomes following valvular heart surgery in Africa.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-analysis guideline was utilized. Electronic searches were performed using PubMed, African journal online, and Research gate from inception to June 2023. The primary endpoints were overall mortality and 30-day mortality, and secondary endpoints included postoperative complications, length of hospital, and intensive care stays. The outcome data were pooled together and analyzed with the random effect model for proportions and mean for meta-analysis using the R software.

RESULTS

This systematic review identified 31 studies that fulfilled the study eligibility criteria and all were observational studies. The countries in which these studies were carried out include South Africa, Ethiopia, Egypt, Mali, Rwanda, Nigeria, Cameroon, Ghana, Senegal, Tanzania, and Kenya. Statistical analysis reported a pooled overall mortality of 10.48% and a pooled 30-day mortality of 4.59%.

CONCLUSION

Several obstacles, such as lack of financial resources and inadequate infrastructure, continue to impede valvular heart surgery practice in many parts of Africa. Future studies need to focus on identifying factors associated with this poor early mortality.

Durability of Biological Valves Implanted in Aortic or Mitral Positions: A Nationwide Cohort Study

BACKGROUND

Biologic prostheses are being increasingly used for aortic and mitral valve replacement (AVR and MVR). This study evaluated the long-term durability of bioprosthetic valves in the mitral and aortic positions, as no well-designed population-based studies have addressed this issue before.

METHODS

Using Taiwan's National Health Insurance Research Database, we compared biologic valve durability in the mitral and aortic positions in patients hospitalized between 2001 and 2017, with reoperation as the primary outcome. Both between-subject and within-subject designs were used, and the propensity score matching cohort (1:1 ratio) was created for the former.

RESULTS

We identified a total of 10,308 patients, 5462 of whom received AVR, 3901 received MVR, and 945 received double valve replacement. Both AVR and MVR cohorts had 2259 patients after matching. During a mean follow-up of 4.2 years (range, 1 day to 17.9 years), the reoperation rate in the MVR cohort (3.5%) was higher than that in the AVR cohort (2.6%) (hazard ratio 1.41; 95% CI, 1.01-1.98). A higher risk of all-cause death was observed in the MVR cohort (36.5%) than in the AVR cohort (32.6%) (hazard ratio 1.21; 95% CI, 1.10-1.34). Among patients receiving double valve replacement with the same prosthesis type, valves implanted in the aortic position were considerably less likely to require reimplantation.

CONCLUSIONS

Bioprosthetic valve placement in the aortic position is associated with superior outcomes in terms of durability, long-term mortality, and perioperative morbidity. Developing novel interventions and enhancing valve durability would expand bioprosthesis use for valve replacement.

The Role of «Novel» Biomarkers of Systemic Inflammation in the Development of Early Hospital Events after Aortic Valve Replacement in Patients with Aortic Stenosis

INTRODUCTION

The pathogenesis of aortic stenosis includes the processes of chronic inflammation, calcification, lipid metabolism disorders, and congenital structural changes. The goal of our study was to determine the predictive value of novel biomarkers of systemic inflammation and some hematological indices based on the numbers of leukocytes and their subtypes in the development of early hospital medical conditions after mechanical aortic valve replacement in patients with aortic stenosis.

MATERIALS AND METHODS

This was a cohort study involving 363 patients who underwent surgical intervention for aortic valve pathology between 2014 and 2020. The following markers of systemic inflammation and hematological indices were studied: SIRI (Systemic Inflammation Response Index), SII (Systemic Inflammation Index), AISI (Aggregate Index of Systemic Inflammation), NLR (Neutrophil/Lymphocyte Ratio), PLR (Platelet/Lymphocyte Ratio), and MLR (Monocyte/Lymphocyte Ratio). Associations of the levels of these biomarkers and indices with the development of in-hospital death, acute kidney injury, postoperative atrial fibrillation, stroke/acute cerebrovascular accident, and bleeding were calculated.

RESULTS

According to an ROC analysis, an SIRI > 1.5 (p < 0.001), an SII > 718 (p = 0.002), an AISI > 593 (p < 0.001), an NLR > 2.48 (p < 0.001), a PLR > 132 (p = 0.004), and an MLR > 0.332 (p < 0.001) were statistically significantly associated with in-hospital death. Additionally, an SIRI > 1.5 (p < 0.001), an NLR > 2.8 (p < 0.001), and an MLR > 0.392 (p < 0.001) were associated with bleeding in the postoperative period. In a univariate logistic regression, SIRI, SII, AISI, and NLR were statistically significant independent factors associated with in-hospital death. In a multivariate logistic regression model, SIRI was the most powerful marker of systemic inflammation.

CONCLUSION

SIRI, SII, AISI, and NLR as novel biomarkers of systemic inflammation were associated with in-hospital mortality. Of all markers and indices of systemic inflammation in our study, SIRI was the strongest predictor of a poor outcome in the multivariate regression model.

An In-Hospital Mortality Risk Model for Elderly Patients Undergoing Cardiac Valvular Surgery Based on LASSO-Logistic Regression and Machine Learning

BACKGROUND

To preferably evaluate and predict the risk for in-hospital mortality in elderly patients receiving cardiac valvular surgery, we developed a new prediction model using least absolute shrinkage and selection operator (LASSO)-logistic regression and machine learning (ML) algorithms.

METHODS

Clinical data including baseline characteristics and peri-operative data of 7163 elderly patients undergoing cardiac valvular surgery from January 2016 to December 2018 were collected at 87 hospitals in the Chinese Cardiac Surgery Registry (CCSR). Patients were divided into training (N = 5774 [80%]) and testing samples (N = 1389 [20%]) according to their date of operation. LASSO-logistic regression models and ML models were used to analyze risk factors and develop the prediction model. We compared the discrimination and calibration of each model and EuroSCORE II.

RESULTS

A total of 7163 patients were included in this study, with a mean age of 69.8 (SD 4.5) years, and 45.0% were women. Overall, in-hospital mortality was 4.05%. The final model included seven risk factors: age, prior cardiac surgery, cardiopulmonary bypass duration time (CPB time), left ventricular ejection fraction (LVEF), creatinine clearance rate (CCr), combined coronary artery bypass grafting (CABG) and New York Heart Association (NYHA) class. LASSO-logistic regression, linear discriminant analysis (LDA), support vector classification (SVC) and logistic regression (LR) models had the best discrimination and calibration in both training and testing cohorts, which were superior to the EuroSCORE II.

CONCLUSIONS

The mortality rate for elderly patients undergoing cardiac valvular surgery was relatively high. LASSO-logistic regression, LDA, SVC and LR can predict the risk for in-hospital mortality in elderly patients receiving cardiac valvular surgery well.

A systemic congestive index (systemic pulse pressure to central venous pressure ratio) predicts adverse outcomes in patients undergoing valvular heart surgery

Background and Aims

Invasive hemodynamics may provide a more nuanced assessment of cardiac function and risk phenotyping in patients undergoing cardiac surgery. The systemic pulse pressure (SPP) to central venous pressure (CVP) ratio represents an integrated index of right and left ventricular function and thus may demonstrate an association with valvular heart surgery outcomes. This study hypothesized that a low SPP/CVP ratio would be associated with mortality in valvular surgery patients.

Methods

This retrospective cohort study examined adult valvular surgery patients with preoperative right heart catheterization from 2007 through 2016 at a single tertiary medical center (n = 215). Associations between the SPP/CVP ratio and mortality were investigated with univariate and multivariate analyses.

Results

Among 215 patients (age 69.7 ± 12.4 years; 55.8% male), 61 died (28.4%) over a median follow‐up of 5.9 years. A SPP/CVP ratio <7.6 was associated with increased mortality (relative risk 1.70, 95% confidence interval [CI] 1.08–2.67, p = .019) and increased length of stay (11.56 ± 13.73 days vs. 7.93 ± 4.92 days, p = .016). It remained an independent predictor of mortality (adjusted odds ratio 3.99, 95% CI 1.47–11.45, p = .008) after adjusting for CVP, mean pulmonary artery pressure, aortic stenosis, tricuspid regurgitation, smoking status, diabetes mellitus, dialysis, and cross‐clamp time.

Conclusions

A low SPP/CVP ratio was associated with worse outcomes in patients undergoing valvular heart surgery. This metric has potential utility in preoperative risk stratification to guide patient selection, prognosis, and surgical outcomes.

Mortality and morbidity of surgical and transcatheter mitral valve repair in octogenarians: A systematic review

BACKGROUND

Valvular heart disease (VHD) is a prominent problem in healthcare today with mitral regurgitation (MR) being the leading cause of VHD in the elderly population. While mitral valve repair (MVr) surgery is one of the only options for the end-stage disease, octogenarians are often denied MVr due to concerns with operative mortality and postoperative morbidity. To provide information on this underrepresented group of surgical patients, a systematic approach was taken to review the mortality and morbidity rates of octogenarians who received MVr.

METHODS

Pubmed and Medline were searched for articles containing outcomes of octogenarians receiving surgical mitral valve repair (SMVr) or transcatheter mitral valve repair (TMVr) published after 2000. Ten articles met the inclusion criteria for a total of 7968 patients included in the analysis using Microsoft Excel, Version 2105.

RESULTS

Short-term mortality rates for SMVr and TMVr were 2.6% and 1.4% for in-hospital, and 7.8% and 3.3% for 30 days, respectively. The average incidence of stroke, acute kidney injury, infection, and major bleeding for SMVr were 3.2%, 11.2%, 7.7%, and 24%, respectively, and 0.3%, 6.7%, 2.7%, and 7.9% for TMVr, respectively.

CONCLUSION

Octogenarians receiving SMVr or TMVr experienced similar rates of short-term mortality and morbidity as younger populations, and when considering life expectancy, midterm mortality was also similar. With these results, denying octogenarians MVr operations based on age alone should be reconsidered. Depending on risk factors and comorbidities, either SMVr or TMVr is a viable and relatively safe option for octogenarians with severe MR.

Predictors of Mortality Following Aortic Valve Replacement in Aortic Stenosis Patients

Background: Understanding of the risk factors for the development of adverse outcomes after aortic valve replacement is necessary to develop timely preventive measures and to improve the results of surgical treatment. Methods: We analyzed patients with aortic stenosis (n = 742) who underwent surgical treatment in the period 2014−2020. The average age was 63 (57;69) years—men 58%, women 42%. Results: The hospital mortality rate was 3% (22 patients). The following statistically significant threshold values (cut-off points) were obtained in the ROC analysis: aortic cross-clamp time > 93 min AUC (CI) 0.676 (0.640−0.710), p = 0.010; cardiopulmonary bypass time > 144 min AUC (CI) 0.809 (0.778−0.837), p < 0.0001, hemoglobin before op <120 g/L. AUC (CI) 0.762 (0.728−0.793), p < 0.0001, hematocrit before op <39% AUC (CI) 0.755 (0.721−0.786), p < 0.001, end-diastolic dimension index >2.39 AUC (CI) 0.647 (0.607−0.686), p = 0.014, end-systolic dimension index > 1.68 AUC (CI) 0.657 (0.617−0.695), p = 0.009. Statistically significant independent predictors of hospital mortality were identified: BMI > 30 kg/m2 (OR 2.84; CI 1.15−7.01), ischemic heart disease (OR 3.65; CI 1.01−13.2), diabetes (OR 3.88; CI 1.38−10.9), frequent ventricular ectopy before operation (OR 9.78; CI 1.91−50.2), mitral valve repair (OR 4.47; CI 1.76−11.3), tricuspid valve repair (OR 3.06; CI 1.09−8.58), 3 and more procedures (OR 4.44; CI 1.67−11.8). Conclusions: The hospital mortality rate was 3%. The main indicators associated with the risk of death were: diabetes, overweight (body mass index more than 30 kg/m2), frequent ventricular ectopy before surgery, hemoglobin level below 120 g/L, hematocrit level below 39%, longer cardiopulmonary bypass time and aortic cross-clamp time, additional mitral and tricuspid valve interventions.

Estimation of required sample size for external validation of risk models for binary outcomes

Risk-prediction models for health outcomes are used in practice as part of clinical decision-making, and it is essential that their performance be externally validated. An important aspect in the design of a validation study is choosing an adequate sample size. In this paper, we investigate the sample size requirements for validation studies with binary outcomes to estimate measures of predictive performance (C-statistic for discrimination and calibration slope and calibration in the large). We aim for sufficient precision in the estimated measures. In addition, we investigate the sample size to achieve sufficient power to detect a difference from a target value. Under normality assumptions on the distribution of the linear predictor, we obtain simple estimators for sample size calculations based on the measures above. Simulation studies show that the estimators perform well for common values of the C-statistic and outcome prevalence when the linear predictor is marginally Normal. Their performance deteriorates only slightly when the normality assumptions are violated. We also propose estimators which do not require normality assumptions but require specification of the marginal distribution of the linear predictor and require the use of numerical integration. These estimators were also seen to perform very well under marginal normality. Our sample size equations require a specified standard error (SE) and the anticipated C-statistic and outcome prevalence. The sample size requirement varies according to the prognostic strength of the model, outcome prevalence, choice of the performance measure and study objective. For example, to achieve an SE < 0.025 for the C-statistic, 60–170 events are required if the true C-statistic and outcome prevalence are between 0.64–0.85 and 0.05–0.3, respectively. For the calibration slope and calibration in the large, achieving SE < 0.15 would require 40–280 and 50–100 events, respectively. Our estimators may also be used for survival outcomes when the proportion of censored observations is high.

National study: Most elderly patients benefit from earlier hip fracture surgery despite co-morbidity

OBJECTIVE

To estimate the potential influence of pre-operative patient condition on the benefit of earlier hip fracture surgery for elderly patients.

BACKGROUND

Many studies emphasize the benefit of earlier hip fracture surgery for patient survival. However less is known regarding how this relationship is influenced by clinical factors which could serve as potential contra-indicators for earlier surgery. Rushed surgery of patients with contra-indications may even compromise their survival.

METHODS

A retrospective study of patients aged 65 and above with an isolated hip fracture following trauma, based on data from 19 hospitals of the national trauma registry available for the years 2015-2016. Registry data was crossed with data on co-morbidities and medication intake from the biggest health insurance agency in the country, serving more than 50% of the country's population. Mediation analysis was performed on a wide list of co-morbidities, medications and clinical test results in order to establish the mediation of their relationship with inhospital mortality by earlier hip fracture surgery. Factors found significant in the mediation analysis were utilized to adjust a logistic regression for predicting inhospital mortality by function of waiting time to surgery and patient's sex and age.

RESULTS

Anti-coagulant and anti-platelet intake; test results pointing to decreased kidney function and being diagnosed with diabetes or Ischemic Heart Disease were found to be significantly mediated in their influence on inhospital mortality by hip fracture surgery. Despite anti-platelet intake and kidney function having a significant impact on mortality in the multi-variate analysis, the positive effect of earlier hip surgery on survival remained unchanged after adjustment.

CONCLUSIONS

Earlier hip fracture surgery was found to be beneficial for elderly patients even when their co-morbidities and medication intake are taken into account.

Strong for Surgery: Association Between Bundled Risk Factors and Outcomes After Major Elective Surgery in the VA Population

BACKGROUND

Strong for Surgery (S4S) is a public health campaign focused on optimizing patient health prior to surgery by identifying evidence-based modifiable risk factors. The potential impact of S4S bundled risk factors on outcomes after major surgery has not been previously studied. This study tested the hypothesis that a higher number of S4S risk factors is associated with an escalating risk of complications and mortality after major elective surgery in the VA population.

METHODS

The Veterans Affairs Surgical Quality Improvement Program (VASQIP) database was queried for patients who underwent major non-emergent general, thoracic, vascular, urologic, and orthopedic surgeries between the years 2008 and 2015. Patients with complete data pertaining to S4S risk factors, specifically preoperative smoking status, HbA1c level, and serum albumin level, were stratified by number of positive risk factors, and perioperative outcomes were compared.

RESULTS

A total of 31,285 patients comprised the study group, with 16,630 (53.2%) patients having no S4S risk factors (S4S0), 12,323 (39.4%) having one (S4S1), 2,186 (7.0%) having two (S4S2), and 146 (0.5%) having three (S4S3). In the S4S1 group, 60.3% were actively smoking, 35.2% had HbA1c > 7, and 4.4% had serum albumin < 3. In the S4S2 group, 87.8% were smokers, 84.8% had HbA1c > 7, and 27.4% had albumin < 3. Major complications, reoperations, length of stay, and 30-day mortality increased progressively from S4S0 to S4S3 groups. S4S3 had the greatest adjusted mortality risk (adjusted odds radio [AOR] 2.56, p = 0.04) followed by S4S2 (AOR 1.58, p = 0.02) and S4S1 (AOR 1.34, p = 0.02).

CONCLUSION

In the VA population, patients who had all three S4S risk factors, namely active smoking, suboptimal nutritional status, and poor glycemic control, had the greatest risk of postoperative mortality compared to patients with fewer S4S risk factors.

Right Ventricular Dysfunction and Short-Term Outcomes Following Left-Sided Valvular Surgery: An Echocardiographic Study

Background The prognostic value of echocardiographic evaluation of right ventricular (RV) function in patients undergoing left-sided valvular surgery has not been well described. The objective of this study is to determine the role of broad echocardiographic assessment of RV function in predicting short-term outcomes after valvular surgery. Methods and Results Preoperative echocardiographic data, perioperative adverse outcomes, and 30-day mortality were analyzed in patients who underwent left-sided valvular surgery from 2006 to 2014. Echocardiographic parameters used to evaluate RV function include RV fractional area change, tricuspid annular plane systolic excursion, systolic movement of the RV lateral wall using tissue Doppler imaging (S'), RV myocardial performance index, and RV dP/dt. Subjects with at least 3 abnormal parameters out of the 5 aforementioned indices were defined as having significant RV dysfunction. The study included 269 patients with valvular surgery (average age: 67±15, 60.6% male, 148 aortic, and 121 mitral). RV dysfunction was found in 53 (19.7%) patients; 30-day mortality occurred in 20 patients (7.5%). Compared with normal RV function, patients with RV dysfunction had higher 30-day mortality (22.6% versus 3.8%; P=0.01) and were at risk for developing multisystem failure/shock (13.2% versus 3.2%; P=0.01). Multivariate analyses showed that preexisting RV dysfunction was the strongest predictor of increased 30-day mortality (odds ratio: 3.5; 95% CI, 1.1-11.1; P<0.05). Conclusions Preoperative RV dysfunction identified by comprehensive echocardiographic assessment is a strong predictor of adverse outcomes following left-sided valvular surgery.

Impact of sex on long-term outcomes following mitral valve repair

Introduction

Previous studies have identified inferior outcomes for women undergoing mitral valve (MV) surgery compared to men, although the cause of this discrepancy has not been identified. We look to isolate surgical approach to identify any impact that sex has on outcomes in order to better inform clinical decision making.

Materials and methods

In this propensity matched, retrospective, single-center study, outcomes were compared between males and females undergoing a MV repair between 2004 and 2018. The primary outcome was defined as mortality at any point in the follow-up period. Secondary outcomes included stroke, myocardial infarction (MI), repeat revascularization, complications arising from the initial procedure, and postoperative cardiac remodeling.

Results

A total of 188 males and 188 females were included after propensity matching. At a median follow up time of 7.6 years, there were 25 deaths in the male group (26.8%) and 23 in the female group (28.2%) (p = 0.771). There were no significant differences in MI, stroke, post-operative pacemaker insertion, or rehospitalization following MV repair. Left ventricular (LV) size for males was reduced from an initial 55.6 ± 7.3 mm to 49.9 ± 7.4 mm (p < 0.001), and for females from an initial 51.5 ± 7 mm to 46.9 ± 7.1 mm (p < 0.001). LV ejection fraction (LVEF) was reduced with a preoperative LVEF for males of 57.7% ± 8.9% and 53.7% ± 9.6% postoperatively (p = 0.002), and LVEF for females of 57.8% ± 9.1% preoperatively and 54.8% ± 9.2% postoperatively (p < 0.001). Left atrial (LA) volume was reduced from an initial 51 ± 22 ml/m2 to 43.7 ± 25.2 ml/m2 (p < 0.001), and 50.9 ± 19.2 ml/m2 to 44.2 ± 19.8 ml/m2 (p < 0.001), for males and females respectively. LA diameter was reduced for males from an initial 49.7 ± 9.7 mm to 47.3 ± 9.4 mm (p = 0.043), and from 48 ± 8.7 mm to 44.3 ± 9.1 mm for females postoperatively (p = 0.017).

Conclusions

Current literature demonstrates inferior outcomes for females when compared to males undergoing MV surgery with patients undergoing a variety of surgical approaches. The results of this study suggest that surgical intervention for a subset of patients, those undergoing repair of the MV, is safe and offers similar outcomes for males and females.

Immediate outcome following valve surgery for rheumatic heart disease: the first local experience from Ethiopia

BACKGROUND

Rheumatic heart disease is the most common cardiac diseases in developing countries including Ethiopia. The current study aimed to describe the immediate surgical outcome following valve surgery for rheumatic heart disease in Ethiopia.

METHODS

Data were collected through chart abstraction from two centres in Addis Ababa, Ethiopia: the Cardiac Center of Ethiopia and El Ouzier cardiac centre. Included were all patients who were operated for rheumatic valvular heart disease in the mentioned centres by local cardiac surgical team during the period from June 2017 to April 2020. Demographic and clinical characteristics of the study population at admission and within 30 days of the index cardiac surgery were collected. Statistical Package for Social Sciences version 20.0 for windows was used to analyse the data.

RESULT

Of the 114 patients included in the study (median age 31 years with interquartile range of 23-40), 62 (54.4%) of them were female. Surgical procedures done were triple valve surgery 9 (7.9%) patients, mitral and tricuspid valves 26 (22.8%) patients, double-valve 16 (14.0%) patients, single-valve surgery 50.9% (11 aortic and 47 mitral valves) of patients, redo mitral valve surgery 3 (2.6%) patients, and left maze with mitral valve surgery 2 (1.8%) patients. Of the total, 103 (90.4%) of them had mitral valve surgery. Post-operatively, 5 (4.4%) patients died within 30 days following the index surgery.

CONCLUSION

Immediate surgical outcome following valve surgery for rheumatic heart disease had excellent outcome in our setting. This evidence can be taken as a show of success in building local capacity to manage rheumatic heart disease surgically.

The most influential papers in mitral valve surgery; a bibliometric analysis

This study is an analysis of the 100 most cited articles in mitral valve surgery. A bibliometric analysis is a tool to evaluate research performance in a given field. It uses the number of times a publication is cited by others as a proxy marker of its impact. The most cited paper Carpentier et al. discusses mitral valve repair in terms of restoring the geometry of the entire valve rather than simply narrowing the annulus (Carpentier, J Thorac Cardiovasc Surg 86:23–37, 1983). The first successful mitral valve repair was performed by Elliot Cutler at Brigham and Women’s Hospital in 1923 (Cohn et al., Ann Cardiothorac Surg 4:315, 2015). More recently percutaneous and minimally invasive techniques that were originally designed as an option for high risk patients are being trialled in other patient groups (Hajar, Heart Views 19:160–3, 2018). Comparison of percutaneous method with open repair represents an expanding area of research (Hajar, Heart Views 19:160–3, 2018). This study will analyse the top 100 cited papers relevant to mitral valve surgery, identifying the most influential papers that guide current management, the institutions that produce them and the authors involved.

German Aortic Valve Score in Risk Assessment for Surgical Aortic Valve Replacement in a Brazilian Center

OBJECTIVE

To test the German Aortic Valve (GAV) score at our university hospital in patients undergoing isolated aortic valve replacement (AVR).

METHODS

A total of 224 patients who underwent isolated conventional AVR between January 2015 and December 2018 were included. Patients with concomitant procedures and transcatheter aortic valve implantation were excluded. Patients' data were collected and analyzed retrospectively. Patients' risk scores were calculated according to criteria described by GAV score. Sensitivity, specificity, and accuracy (area under the ROC curve [AUC]) were also calculated. The calibration of the model was tested by the Hosmer-Lemeshow method.

RESULTS

The mortality rate was 8.04% (18 patients). The patients' mean age was 58.2±19.3 years and 25% of them were female (56 patients). Mean GAV score was 1.73±5.86 (min: 0.0; max: 3.53). The GAV score showed excellent discriminative capacity (AUC 0.925, 95% confidence interval 0.882-0.956; P<0.001). The cutoff "1.8" turned out to be the best discriminatory point with the best combination of sensitivity (88.9%) and specificity (75.7%) to predict operative death. Hosmer-Lemeshow method revealed a P-value of 0.687, confirming a good calibration of the model.

CONCLUSION

The GAV score applies to our population with high predictive accuracy.

Risk Stratification for Transcatheter Aortic Valve Replacement

Risk assessment models developed from administrative and clinical databases are used for clinical decision making. Since these models are derived from a database, they have an inherent limitation of being as good as the data they are derived from. Many of these models under or overestimate certain clinical outcomes particularly mortality in certain group of patients. Undeniably, there is significant variability in all these models on account of patient population studied, the statistical analysis used to develop the model and the period during which these models were developed. This review aims to shed light on development and application of risk assessment models for cardiac surgery with special emphasis on risk stratification in severe aortic stenosis to select patients for transcatheter aortic valve replacement.

Clinical Prediction Models for Valvular Heart Disease

Background

While many clinical prediction models (CPMs) exist to guide valvular heart disease treatment decisions, the relative performance of these CPMs is largely unknown. We systematically describe the CPMs available for patients with valvular heart disease with specific attention to performance in external validations.

Methods and Results

A systematic review identified 49 CPMs for patients with valvular heart disease treated with surgery (n=34), percutaneous interventions (n=12), or no intervention (n=3). There were 204 external validations of these CPMs. Only 35 (71%) CPMs have been externally validated. Sixty‐five percent (n=133) of the external validations were performed on distantly related populations. There was substantial heterogeneity in model performance and a median percentage change in discrimination of −27.1% (interquartile range, −49.4%–−5.7%). Nearly two‐thirds of validations (n=129) demonstrate at least a 10% relative decline in discrimination. Discriminatory performance of EuroSCORE II and Society of Thoracic Surgeons (2009) models (accounting for 73% of external validations) varied widely: EuroSCORE II validation c‐statistic range 0.50 to 0.95; Society of Thoracic Surgeons (2009) Models validation c‐statistic range 0.50 to 0.86. These models performed well when tested on related populations (median related validation c‐statistics: EuroSCORE II, 0.82 [0.76, 0.85]; Society of Thoracic Surgeons [2009], 0.72 [0.67, 0.79]). There remain few (n=9) external validations of transcatheter aortic valve replacement CPMs.

Conclusions

Many CPMs for patients with valvular heart disease have never been externally validated and isolated external validations appear insufficient to assess the trustworthiness of predictions. For surgical valve interventions, there are existing predictive models that perform reasonably well on related populations. For transcatheter aortic valve replacement (CPMs additional external validations are needed to broadly understand the trustworthiness of predictions.

Trends, characteristics, in-hospital outcomes and mortality in surgical mitral valve replacement among patients with and without COPD in Spain (2001-2015)

PURPOSE

We examined trends, characteristics and in-hospital outcomes in mechanical and bioprosthetic surgical mitral valve replacement (SMVR) among patients with and without chronic obstructive pulmonary disease (COPD) in Spain from 2001 to 2015. We also identified factors associated with in-hospital mortality (IHM) in both groups of patients according to the implanted valve type.

METHODS

We analyzed data from the Spanish National Hospital Discharge Database for patients aged 40 years or over. We selected admissions of patients whose medical procedures included SMVR. We grouped hospitalizations by COPD status.

RESULTS

Over 43,024 patients identified, 83.63% underwent mechanical mitral valve replacement and 16.37% bioprosthetic valve (6.71% and 7.78% with COPD, respectively). The incidence of SMVR decreased for mechanical valves and increased for bioprosthetic valves over time in both groups of patients. The incidence of SMVR admissions was lower among COPD patients than in those without COPD, both for mechanical and bioprosthetic valves. IHM decreased significantly over time, regardless of the type of valve, in both groups of patients. COPD was associated with a significant increase in IHM, but only among patients who underwent bioprosthetic SMVR (OR 1.32, 95% CI 1.01-1.73).

CONCLUSIONS

The incidence of mechanical SMVR decreased while that of bioprosthetic SMVR increased over time in both groups of patients. COPD patients were less surgically operated than non-COPD patients for both valve types. In COPD patients, bioprosthetic SMVR was proportionally more used than mechanical SMVR. Mortality decreased over time for both valve types in patients with and without COPD. COPD increased in-hospital mortality among patients undergoing a biological SMVR.

Independent Effect of Low Flow on Outcomes in Patients Undergoing Aortic Valve Replacement for Severe Aortic Stenosis

BACKGROUND

Low flow (LF; i.e., reduced left ventricular stroke volume index <35 mL/m²) can occur with severe aortic stenosis (AS). However, few studies have investigated the effects of LF on early and late outcomes after aortic valve replacement (AVR) for severe AS.Methods and Results:In all, 285 severe AS patients undergoing isolated AVR at Juntendo University Hospital between August 2002 and August 2015 were enrolled in the study. In this cohort, 52 patients (18%) had LF. Compared with patients with normal flow (NF) severe AS, early postoperative mortality (9.6% vs. 1.2%; P=0.006), gastrointestinal complications (5.7% vs. 0.8%; P=0.04), and the duration of the intensive care unit (ICU) stay (81.7 vs. 35.3 h; P=0.02) were increased in LF patients with severe AS. LF was an independent predictor of early mortality (Model A, odds ratio [OR] 6.81, P=0.01; Model B, OR 6.69, P=0.01) and composite complications (Model A, OR 2.44, P=0.02). In propensity score-matched comparisons, early mortality (12.8% vs. 0%; P=0.02), composite complications (28.2% vs. 10.2%; P=0.04), and duration of ICU stay (97.4 vs. 22.1 h; P=0.006) were significantly increased in LF than NF patients.

CONCLUSIONS

LF, as an important independent risk factor for postoperative mortality and morbidity, should be included in risk stratification and assessment in severe AS patients.

Predictive performance of six mortality risk scores and the development of a novel model in a prospective cohort of patients undergoing valve surgery secondary to rheumatic fever

BACKGROUND

Mortality prediction after cardiac procedures is an essential tool in clinical decision making. Although rheumatic cardiac disease remains a major cause of heart surgery in the world no previous study validated risk scores in a sample exclusively with this condition.

OBJECTIVES

Develop a novel predictive model focused on mortality prediction among patients undergoing cardiac surgery secondary to rheumatic valve conditions.

METHODS

We conducted prospective consecutive all-comers patients with rheumatic heart disease (RHD) referred for surgical treatment of valve disease between May 2010 and July of 2015. Risk scores for hospital mortality were calculated using the 2000 Bernstein-Parsonnet, EuroSCORE II, InsCor, AmblerSCORE, GuaragnaSCORE, and the New York SCORE. In addition, we developed the rheumatic heart valve surgery score (RheSCORE).

RESULTS

A total of 2,919 RHD patients underwent heart valve surgery. After evaluating 13 different models, the top performing areas under the curve were achieved using Random Forest (0.982) and Neural Network (0.952). Most influential predictors across all models included left atrium size, high creatinine values, a tricuspid procedure, reoperation and pulmonary hypertension. Areas under the curve for previously developed scores were all below the performance for the RheSCORE model: 2000 Bernstein-Parsonnet (0.876), EuroSCORE II (0.857), InsCor (0.835), Ambler (0.831), Guaragna (0.816) and the New York score (0.834). A web application is presented where researchers and providers can calculate predicted mortality based on the RheSCORE.

CONCLUSIONS

The RheSCORE model outperformed pre-existing scores in a sample of patients with rheumatic cardiac disease.

Malignant disease as a comorbidity in patients with severe aortic stenosis: clinical presentation, outcomes, and management

Aim

To investigate the effect of malignancy on the outcomes of patients with severe aortic stenosis (AS) and the management strategy for AS with malignancy.

Methods and results

Using data of 3815 patients with severe AS in a retrospective multicentre registry [CURRENT AS (Contemporary outcomes after sURgery and medical tREatmeNT in patients with severe Aortic Stenosis) registry], we compared 3-year clinical outcomes among three groups based on malignancy status: with malignancy currently under treatment including best supportive care (malignancy group), with a history of malignancy without any current treatment (past history group), or without history of malignancy (no malignancy group). Patients in the malignancy group (n = 124) were more often men and had higher prevalence of low body mass index, recurrence of malignancy, anaemia, and asymptomatic status, despite comparable surgical risks and echocardiographic parameters. The malignancy group or the past history group (n = 389) had significantly higher risk for all-cause death [hazard ratio (HR) 2.49, 95% CI (95% confidence interval) 1.98-3.14; HR 1.23, 95% CI 1.04-1.46] and for malignancy-related death (HR 16.2, 95% CI 10.64-24.54; HR 3.66, 95% CI 2.43-5.52) than that of the no malignancy group (n = 3302). The excess risk for aortic valve-related death was not observed in the malignancy group (HR 0.79, 95% CI 0.48-1.29) and was lower in the past history group (HR 0.72, 95% CI 0.53-0.96). In the malignancy group, the treatment strategy (surgery: n = 16, conservative management: n = 108) was determined based on the clinical status of AS or life expectancy.

Conclusions

Malignancy had marked effect on all-cause death and malignancy-related death in patients with severe AS. History of malignancy also had a smaller but significant effect on mortality.

Mechanisms of aortic stenosis

The pathobiology of degenerative aortic valve stenosis (AS) is complex and involves multiple features such as fibrosis, inflammation, oxidative stress, angiogenesis, hemorrhage, and osteogenic differentiation. We summarize the mechanism of valve calcification and angiogenesis which is necessary for calcifying processes. A promising therapeutic target is nuclear factor (NF)-κB which activates bone morphogenetic protein (BMP)2 via interleukin-6. BMP2 activates Wnt signaling via msh homeobox 2 causing osteogenic differentiation. BMP2 also activates Runx2/Cbfa1 which is an osteoblast-specific transcription factor. Signals in the hypoxia-inducible factor-2 axis activated by the NF-κB signaling pathway also play important role in calcifying processes including angiogenesis. The reason why angiogenesis takes place in avascular valves is still unknown, but it is likely angiogenesis and angiogenesis-related hemorrhage play critical roles in the progression of AS.

Validation of German Aortic Valve Score in a Multi-Surgeon Single Center

OBJECTIVE:

Risk assessment for operative mortality is mandatory for all cardiac operations. For some operation types such as aortic valve repair, EuroSCORE II overestimates the mortality rate and a new scoring system (German AV score) has been developed for a more accurate assessment of operative risk. In this study, we aimed to validate German Aortic Valve Score in our clinic in patients undergoing isolated aortic valve replacement.

METHODS:

A total of 35 patients who underwent isolated open aortic valve replacement between 2010 and 2013 were included. Patients with concomitant procedures and transcatheter aortic valve implantation were excluded. Patients' data were collected and analyzed retrospectively. Patients' risk scores EuroSCORE II were calculated online according to criteria described by EuroSCORE taskforce, Aortic Valve Scores were also calculated.

RESULTS:

The mean age of patients was 61.14±13.25 years (range 29-80 years). The number of female patients was 14 (40%) and body mass index of 25 (71.43%) patients was in range of 22-35. Mean German Aortic Valve Score was 1.05±0.96 (min: 0 max: 4.98) and mean EuroSCORE was 2.30±2.60 (min: 0.62, max: 2.30). The Aortic Valve Score scale showed better discriminative capacity (AUC 0.647, 95% CI 0.439-0.854). The goodness of fit was x2HL=16.63; P=0.436). EuroSCORE II scale had shown less discriminative capacity (AUC 0.397, 95% CI 0.200-0.597). The goodness of fit was good for both scales. The goodness of fit was x2HL=30.10; P=0.610.

CONCLUSION:

In conclusion, German AV score applies to our population with high predictive accuracy and goodness of fit.

Review and evaluation of performance measures for survival prediction models in external validation settings

BACKGROUND

When developing a prediction model for survival data it is essential to validate its performance in external validation settings using appropriate performance measures. Although a number of such measures have been proposed, there is only limited guidance regarding their use in the context of model validation. This paper reviewed and evaluated a wide range of performance measures to provide some guidelines for their use in practice.

METHODS

An extensive simulation study based on two clinical datasets was conducted to investigate the performance of the measures in external validation settings. Measures were selected from categories that assess the overall performance, discrimination and calibration of a survival prediction model. Some of these have been modified to allow their use with validation data, and a case study is provided to describe how these measures can be estimated in practice. The measures were evaluated with respect to their robustness to censoring and ease of interpretation. All measures are implemented, or are straightforward to implement, in statistical software.

RESULTS

Most of the performance measures were reasonably robust to moderate levels of censoring. One exception was Harrell's concordance measure which tended to increase as censoring increased.

CONCLUSIONS

We recommend that Uno's concordance measure is used to quantify concordance when there are moderate levels of censoring. Alternatively, Gönen and Heller's measure could be considered, especially if censoring is very high, but we suggest that the prediction model is re-calibrated first. We also recommend that Royston's D is routinely reported to assess discrimination since it has an appealing interpretation. The calibration slope is useful for both internal and external validation settings and recommended to report routinely. Our recommendation would be to use any of the predictive accuracy measures and provide the corresponding predictive accuracy curves. In addition, we recommend to investigate the characteristics of the validation data such as the level of censoring and the distribution of the prognostic index derived in the validation setting before choosing the performance measures.

[EuroSCORE underestimate the mortality risk in cardiac valve surgery of Mexican population]

OBJECTIVE

The EuroSCORE (European System for cardiac operative risk evaluation) stratifies cardiac risk surgery in easy and accessible manner; it was validated in North America with good results but in many countries of Latin America is used routinely without prior validation. Our objective was to validate the EuroSCORE in patients with cardiac valve surgery at the Instituto Nacional de Cardiología Ignacio Chávez (INCICh) in México.

METHODS

EuroSCORE additive and logistic models were used to predict mortality in adults undergoing cardiac valve surgery from march 2004 to march 2008. The goodness of fit test of Hosmer-Lemeshow was used to evaluate the calibration. The area under the ROC curve was calculated to determinate discrimination.

RESULTS

We included 1188 patients with ages of 51.3±14.5 years, 52% women. There were significant differences in the prevalence of risk factors among the INCICh and the EuroSCORE populations. Total mortality was 9.68% versus 5% and 5.6% predicted by additive and logistic EuroSCORE. According to additive EuroSCORE the risk was low in 11.3%, intermediate in 52.9% and high in 35.9%; for these groups the mortality was .7%, 6.34% and 17.4% against those predicted of 2%, 3.9% and 7.64%. Hosmer-Lemeshow test had a P<.001 for both models and the area under the ROC curve was .707 and .694 for additive and logistic EuroSCORE.

CONCLUSION

In the INCICh 88.7% of patients with cardiac valve surgery had intermediate to high risk and EuroSCORE underestimated the risk of mortality.

Comparison of four risk scores for in-hospital mortality in patients undergoing heart valve surgery: A multicenter study in a Chinese population

BACKGROUND AND AIM OF THE STUDY

To compare four risk scores with regard to their validity to predict in-hospital mortality after heart valve surgery in a multicenter patient population of China.

MATERIALS AND METHODS

From January 2009 to December 2012, data from 12,412 consecutive patients older than 16 years who underwent heart valve surgery at four cardiac surgical centers were collected and scored according to the EuroSCORE II, Ambler risk score, NYC risk score, and STS risk score. The patients were divided into two subgroups according to the types of valve procedures, and the performance of the four risk scores for each group was assessed. Calibration was assessed by the Hosmer-Lemeshow (H-L) test. Discrimination was tested by calculating the area under the receiver operating characteristic (ROC) curve.

RESULTS

Observed mortality was 2.09% overall. The EuroSCORE II, Ambler score, and NYC score overpredicted observed mortality (Hosmer-Lemeshow: P = 0.002, P < 0.0001, and P < 0.0001, respectively) and the STS score underpredicted observed mortality (Hosmer-Lemeshow: P = 0.001). The discriminative power in the entire cohort for in-hospital mortality was highest for the STS score (0.735), followed by the EuroSCORE II score (0.704), NYC score (0.693), and Ambler score (0.674). Meanwhile, the STS score and EuroSCORE II give an accurate prediction in patients undergoing single valve surgery compared with the Ambler score and NYC score. However, all four risk scores give an imprecise prediction in patients undergoing multiple valve surgery.

CONCLUSIONS

Both the STS score and Euroscore II, especially the STS score, were suitable for individual operative risk in Chinese patients undergoing single valve surgery compared with the Ambler score and NYC score, however, all four risk scores were not suitable for prediction in Chinese patients undergoing multiple valve surgery. Therefore, the creation of a new model which accurately predicts outcomes in patients undergoing multiple valve surgery is possibly required in China.

[Transcatheter aortic valve implantation (TAVI): Current perspectives]

Transcatheter aortic valve implantation (TAVI) has evolved as the treatment modality of choice for elderly patients with symptomatic severe aortic stenosis who are at high risk for surgery. More than 10,000 TAVI procedures were undertaken in Germany during 2014.A mortality benefit has been shown for TAVI compared with conservative treatment in patients deemed inoperable, and the procedure was proven to be at least non-inferior to surgical aortic valve replacement in high-risk patients. Through improvements in preprocedural imaging and in valve technology as well as increasing operator and surgical team experience, TAVI has developed rapidly in the past few years. Complication rates declinded considerably and the latest study results even suggest a superiority of TAVI to surgical valve replacement in patients at intermediate operative risk. Nevertheless, the challenge to avoid procedure-specific complications influencing the outcome still remains. Therefore, making an individual decision about the approach and the valve prosthesis in an interdisciplinary heart team consisting of a cardiologist and a cardiac surgeon is indispensable for guaranteeing the best therapy for the patient.Considering the rapid developments and procedural improvements in this field, randomized trials are required to assess whether the indication for TAVI may be extended to patients at lower perioperative risk in the future.

Pigtail catheter "propping" for MitraClip percutaneous transcatheter mitral valve repair

In recent years percutaneous therapy has emerged as a feasible and effective option for the treatment of mitral regurgitation, particularly in cases where the risks of conventional cardiac surgery are prohibitively high. To date the most widely used percutaneous approach is beating heart, edge-to-edge repair with the MitraClip device (Abbott Vascular-Structural Heart, Menlo Park, CA). The technique requires simultaneous grasping and approximation of both mitral valve leaflets prior to securing and releasing the clip. However, this may be technically challenging or indeed impossible in patients with failure of coaptation, particularly when there is a large coaptation gap. We present an approach for overcoming this relatively common obstacle based on "propping" the anterior mitral valve leaflet toward its posterior counterpart with a diagnostic pigtail catheter to reduce the coaptation gap and to allow grasping of both leaflets without difficulty. © 2016 Wiley Periodicals, Inc.

Calcific aortic stenosis

Calcific aortic stenosis (AS) is the most prevalent heart valve disorder in developed countries. It is characterized by progressive fibro-calcific remodelling and thickening of the aortic valve leaflets that, over years, evolve to cause severe obstruction to cardiac outflow. In developed countries, AS is the third-most frequent cardiovascular disease after coronary artery disease and systemic arterial hypertension, with a prevalence of 0.4% in the general population and 1.7% in the population >65 years old. Congenital abnormality (bicuspid valve) and older age are powerful risk factors for calcific AS. Metabolic syndrome and an elevated plasma level of lipoprotein(a) have also been associated with increased risk of calcific AS. The pathobiology of calcific AS is complex and involves genetic factors, lipoprotein deposition and oxidation, chronic inflammation, osteoblastic transition of cardiac valve interstitial cells and active leaflet calcification. Although no pharmacotherapy has proved to be effective in reducing the progression of AS, promising therapeutic targets include lipoprotein(a), the renin-angiotensin system, receptor activator of NF-κB ligand (RANKL; also known as TNFSF11) and ectonucleotidases. Currently, aortic valve replacement (AVR) remains the only effective treatment for severe AS. The diagnosis and staging of AS are based on the assessment of stenosis severity and left ventricular systolic function by Doppler echocardiography, and the presence of symptoms. The introduction of transcatheter AVR in the past decade has been a transformative therapeutic innovation for patients at high or prohibitive risk for surgical valve replacement, and this new technology might extend to lower-risk patients in the near future.

Early High-Volume Hemofiltration versus Standard Care for Post-Cardiac Surgery Shock. The HEROICS Study

RATIONALE

Post-cardiac surgery shock is associated with high morbidity and mortality. By removing toxins and proinflammatory mediators and correcting metabolic acidosis, high-volume hemofiltration (HVHF) might halt the vicious circle leading to death by improving myocardial performance and reducing vasopressor dependence.

OBJECTIVES

To determine whether early HVHF decreases all-cause mortality 30 days after randomization.

METHODS

This prospective, multicenter randomized controlled trial included patients with severe shock requiring high-dose catecholamines 3-24 hours post-cardiac surgery who were randomized to early HVHF (80 ml/kg/h for 48 h), followed by standard-volume continuous venovenous hemodiafiltration (CVVHDF) until resolution of shock and recovery of renal function, or conservative standard care, with delayed CVVHDF only for persistent, severe acute kidney injury.

MEASUREMENTS AND MAIN RESULTS

On Day 30, 40 of 112 (36%) HVHF and 40 of 112 (36%) control subjects (odds ratio, 1.00; 95% confidence interval, 0.64-1.56; P = 1.00) had died; only 57% of the control subjects had received renal-replacement therapy. Between-group survivors' Day-60, Day-90, intensive care unit, and in-hospital mortality rates, Day-30 ventilator-free days, and renal function recovery were comparable. HVHF patients experienced faster correction of metabolic acidosis and tended to be more rapidly weaned off catecholamines but had more frequent hypophosphatemia, metabolic alkalosis, and thrombocytopenia.

CONCLUSIONS

For patients with post-cardiac surgery shock requiring high-dose catecholamines, the early HVHF onset for 48 hours, followed by standard volume until resolution of shock and recovery of renal function, did not lower Day-30 mortality and did not impact other important patient-centered outcomes compared with a conservative strategy with delayed CVVHDF initiation only for patients with persistent, severe acute kidney injury. Clinical trial registered with www.clinicaltrials.gov (NCT 01077349).

Optimizing clinical outcomes of transcatheter aortic valve implantation patients with comorbidities

Transcatheter aortic valve implantation (TAVI) has revolutionized the management of high-risk or inoperable patients presenting with symptomatic severe aortic stenosis (AS). There are several factors to consider to optimize patient outcomes from TAVI. Before TAVI, patient selection is key and an understanding the effects of common comorbidities on outcomes after TAVI is critical. Some comorbidities share common risk factors with AS (e.g. coronary artery disease), others are directly or indirectly caused or exacerbated by severe AS (e.g. atrial fibrillation, pulmonary hypertension, mitral regurgitation, tricuspid regurgitation and right ventricular dysfunction), whereas others are not directly related to severe AS (e.g. chronic kidney disease and chronic lung disease). Choice of transcatheter heart valve prosthesis, vascular access route and mode of anesthesia are important considerations during TAVI. New onset conduction disturbances and arrhythmias remain a vexing issue after TAVI. The aim of the present review is to provide an overview of these issues.

How to develop a more accurate risk prediction model when there are few events

When the number of events is low relative to the number of predictors, standard regression could produce overfitted risk models that make inaccurate predictions. Use of penalised regression may improve the accuracy of risk prediction

Performance of surgical risk scores to predict mortality after transcatheter aortic valve implantation

Background

Predicting mortality in patients undergoing transcatheter aortic valve implantation (TAVI) remains a challenge.

Objectives

To evaluate the performance of 5 risk scores for cardiac surgery in predicting the 30-day mortality among patients of the Brazilian Registry of TAVI.

Methods

The Brazilian Multicenter Registry prospectively enrolled 418 patients undergoing TAVI in 18 centers between 2008 and 2013. The 30-day mortality risk was calculated using the following surgical scores: the logistic EuroSCORE I (ESI), EuroSCORE II (ESII), Society of Thoracic Surgeons (STS) score, Ambler score (AS) and Guaragna score (GS). The performance of the risk scores was evaluated in terms of their calibration (Hosmer–Lemeshow test) and discrimination [area under the receiver–operating characteristic curve (AUC)].

Results

The mean age was 81.5 ± 7.7 years. The CoreValve (Medtronic) was used in 86.1% of the cohort, and the transfemoral approach was used in 96.2%. The observed 30-day mortality was 9.1%. The 30-day mortality predicted by the scores was as follows: ESI, 20.2 ± 13.8%; ESII, 6.5 ± 13.8%; STS score, 14.7 ± 4.4%; AS, 7.0 ± 3.8%; GS, 17.3 ± 10.8%. Using AUC, none of the tested scores could accurately predict the 30-day mortality. AUC for the scores was as follows: 0.58 [95% confidence interval (CI): 0.49 to 0.68, p = 0.09] for ESI; 0.54 (95% CI: 0.44 to 0.64, p = 0.42) for ESII; 0.57 (95% CI: 0.47 to 0.67, p = 0.16) for AS; 0.48 (95% IC: 0.38 to 0.57, p = 0.68) for STS score; and 0.52 (95% CI: 0.42 to 0.62, p = 0.64) for GS. The Hosmer–Lemeshow test indicated acceptable calibration for all scores (p > 0.05).

Conclusions

In this real world Brazilian registry, the surgical risk scores were inaccurate in predicting mortality after TAVI. Risk models specifically developed for TAVI are required.

The management of patients with aortic regurgitation and severe left ventricular dysfunction: a systematic review

A systematic search of Medline, EMBASE and CINAHL electronic databases was performed. Original research articles reporting all-cause mortality following surgery in patients with aortic regurgitation and severe left ventricular systolic dysfunction (LVSD) were identified. Nine of the 10 eligible studies were observational, single-center, retrospective analyses. Survival ranged from 86 to 100% at 30 days; 81 to 100% at 1 year and 68 to 84% at 5 years. Three studies described an improvement in mean left ventricular ejection fraction (LVEF) following aortic valve replacement (AVR) of 5-14%; a fourth study reported an increase in mean left ventricular ejection fraction (LVEF) of 9% in patients undergoing isolated AVR but not when AVR was combined with coronary artery bypass graft and/or mitral valve surgery. Three studies demonstrated improvements in functional New York Heart Association (NYHA) class following AVR. Additional studies are needed to clarify the benefits of AVR in patients with more extreme degrees of left ventricular systolic dysfunction (LVSD) and the potential roles of cardiac transplantation and transaortic valve implantation.

Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD): explanation and elaboration

The TRIPOD (Transparent Reporting of a multivariable prediction model for Individual Prognosis Or Diagnosis) Statement includes a 22-item checklist, which aims to improve the reporting of studies developing, validating, or updating a prediction model, whether for diagnostic or prognostic purposes. The TRIPOD Statement aims to improve the transparency of the reporting of a prediction model study regardless of the study methods used. This explanation and elaboration document describes the rationale; clarifies the meaning of each item; and discusses why transparent reporting is important, with a view to assessing risk of bias and clinical usefulness of the prediction model. Each checklist item of the TRIPOD Statement is explained in detail and accompanied by published examples of good reporting. The document also provides a valuable reference of issues to consider when designing, conducting, and analyzing prediction model studies. To aid the editorial process and help peer reviewers and, ultimately, readers and systematic reviewers of prediction model studies, it is recommended that authors include a completed checklist in their submission. The TRIPOD checklist can also be downloaded from www.tripod-statement.org.

Percutaneous mitral valve repair

Nonsurgical treatment of clinically important mitral regurgitation (MR) has evolved tremendously over the past decade. Recent studies of percutaneous mitral valve repair procedures have shown that less invasive procedures are safe and can be effective in selected patients. MitraClip has been studied most extensively. The MitraClip is attached to the middle scallop of the mitral leaflets by a transseptal-transvascular approach. The device approximates the leaflets in an edge-to-edge percutaneous repair technique that diminishes MR, improves functional status, and improves left ventricular remodeling. The subgroup that has the most benefit includes patients with older age, poorer left ventricular function, and functional MR and is considered high risk for surgical valve replacement. Other novel percutaneous mitral valve therapies under investigation include indirect and direct annuloplasty, and ventricular remodeling devices.