Univariate Risk Factors for Prolonged Mechanical Ventilation in Patients Undergoing Prosthetic Heart Valves Replacement Surgery

Data from 736 patients undergoing prosthetic heart valve replacement surgery and concomitant surgery （combined surgery） from January 1998 to January 2004 at Union Hospital were retrospectively reviewed. Univariate logistic regression analyses were conducted to identity risk factors for prolonged mechanical ventilation. The results showed that prolonged cardiopulmonary bypass duration, prolonged aortic cross clamp time and low ejection fraction less than 50 percent （50 %） were found to be independent predictors for prolonged mechanical ventilation. Meanwhile age, weight, and preoperative hospital stay （days） were not found to be associated with prolonged mechanical ventilation. It was concluded that. for age and weight, this might be due to the lower number of old age patients （70 years and above） included in our study and genetic body structure of majority Chinese population that favor them to be in normal weight, respectively.

Risk of permanent pacemaker implantation following transcatheter aortic valve replacement:Which factors are most relevant?

Transcatheter aortic valve replacement(TAVR)has emerged as a formidable treatment option for severe symptomatic aortic stenosis ahead of surgical aortic valve replacement.The encouraging results from large randomized controlled trials has resulted in an exponential rise in the use of TAVR even in the low-risk patients.However,this is not without challenges.Need for permanent pacemaker(PPM)post-TAVR remains the most frequent and clinically relevant challenge.Naturally,identifying risk factors which predispose an individual to develop high grade conduction block post-TAVR is important.Various demographic factors,electrocardiographic features,anatomic factors and procedural characteristics have all been linked to the development of advanced conduction block and need for PPM following TAVR.Amongst these electrophysiological variables,most notably a prolonged QRS>120 ms regardless of the type of conduction block seems to be one of the strongest predictors on logistic regression models.The index study by Nwaedozie et al highlights that patients requiring PPM post-TAVR had higher odds of having a baseline QRS>120 ms and were more likely to be having diabetes mellitus that those who did not require PPM.

Current knowledge for the risk factors of early permanent pacemaker implantation following transcatheter aortic valve replacement and what is next for the primary prevention?

In this editorial,we comprehensively summarized the preoperative risk factors of early permanent pacemaker implantation after transcatheter aortic valve replacement(TAVR)among patients with severe aortic stenosis from several renowned clinical studies and focused on the primary prevention of managing the modifiable factors,e.g.,paroxysmal atrial fibrillation before the TAVR.

Transcatheter aortic valve replacement in low-risk young population:A double edge sword?

Since the advent of transcatheter aortic valve replacement(TAVR)in 2002,it has now become the default interventional strategy for symptomatic patients presenting with severe aortic stenosis,particularly in intermediate to highsurgical risk patients.In 2019,the United States Food and Drug Administration approved TAVR in low-risk patients based on two randomized trials.However,these breakthrough trials excluded patients with certain unfavorable anatomies and odd profiles.While currently there is no randomized study of TAVR in young patients,it may be preferred by the young population given the benefits of early discharge,shorter hospital stay,and expedite recovery.Nonetheless,it is important to ruminate various factors including lifetime expectancy,risk of pacemaker implantation,and the need for future valve or coronary interventions in young cohorts before considering TAVR in these patients.Furthermore,the data on long-term durability(>10 years)of TAVR is still unknown given most of the procedures were initially performed in the high or prohibitive surgical risk population.Thus,this editorial aims to highlight the importance of considering an individualized approach in young patients with consideration of various factors including lifetime expectancy while choosing TAVR against surgical aortic valve replacement.

Pacemaker post transcatheter aortic valve replacement:A multifactorial risk?

Pacemaker post-transcatheter aortic valve replacement is related to multifactorial risk.Nwaedozie et al brought to the body of evidence electrocardiogram and clinical findings.However,procedural characteristics have at least as much impact on the final need for a permanent pacemaker and potentially on the pacing rate.In this regard,long-term follow-up and understanding of the impact of long-term stimulation is of utmost importance.

Novel predictors of permanent pacemaker implantation following transcatheter aortic valve replacement

BACKGROUND Conduction and rhythm abnormalities requiring permanent pacemakers(PPM)are short-term complications following transcatheter aortic valve replacement(TAVR),and their clinical outcomes remain conflicting.Potential novel predictors of post-TAVR PPM,like QRS duration,QTc prolongation,and supraventricular arrhythmias,have been poorly studied.AIM To evaluate the effects of baseline nonspecific interventricular conduction delay and supraventricular arrhythmia on post-TAVR PPM requirement and determine the impact of PPM implantation on clinical outcomes.METHODS RESULTS Out of the 357 patients that met inclusion criteria,the mean age was 80 years,188(52.7%)were male,and 57(16%)had a PPM implantation.Baseline demographics,valve type,and cardiovascular risk factors were similar except for type II diabetes mellitus(DM),which was more prevalent in the PPM cohort(59.6%vs 40.7%;P=0.009).The PPM cohort had a significantly higher rate of pre-procedure right bundle branch block,prolonged QRS>120 ms,prolonged QTc>470 ms,and supraventricular arrhythmias.There was a consistently significant increase in the odds ratio(OR)of PPM implantation for every 20 ms increase in the QRS duration above 100 ms:QRS 101-120[OR:2.44;confidence intervals(CI):1.14-5.25;P=0.022],QRS 121-140(OR:3.25;CI:1.32-7.98;P=0.010),QRS 141-160(OR:6.98;CI:3.10-15.61;P<0.001).After model adjustment for baseline risk factors,the OR remained significant for type II DM(aOR:2.16;CI:1.18-3.94;P=0.012),QRS>120(aOR:2.18;CI:1.02-4.66;P=0.045)and marginally significant for supraventricular arrhythmias(aOR:1.82;CI:0.97-3.42;P=0.062).The PPM cohort had a higher adjusted OR of heart failure(HF)hospitalization(aOR:2.2;CI:1.1-4.3;P=0.022)and nonfatal myocardial infarction(MI)(aOR:3.9;CI:1.1-14;P=0.031)without any difference in mortality(aOR:1.1;CI:0.5-2.7;P=0.796)at one year.CONCLUSION Pre-TAVR type II DM and QRS duration>120,regardless of the presence of bundle branch blocks,are predictors of post-TAVR PPM.At 1-year post-TAVR,patients with PPM have higher odds of HF hospitalization and MI.

Machine Learning Prediction Models of Optimal Time for Aortic Valve Replacement in Asymptomatic Patients

Currently,the decision of aortic valve replacement surgery time for asymptomatic patients with moderate-to-severe aortic stenosis(AS)is made by healthcare professionals based on the patient’s clinical biometric records.A delay in surgical aortic valve replacement(SAVR)can potentially affect patients’quality of life.By using ML algorithms,this study aims to predict the optimal SAVR timing and determine the enhancement in moderate-to-severe AS patient survival following surgery.This study represents a novel approach that has the potential to improve decision-making and,ultimately,improve patient outcomes.We analyze data from 176 patients with moderate-to-severe aortic stenosis who had undergone or were indicated for SAVR.We divide the data into two groups:those who died within the first year after SAVR and those who survived for more than one year or were still alive at the last follow-up.We then use six different ML algorithms,Support Vector Machine(SVM),Classification and Regression Tree(C and R tree),Generalized Linear(GL),Chi-Square Automatic Interaction Detector(CHAID),Artificial Neural Net-work(ANN),and Linear Regression(LR),to generate predictions for the best timing for SAVR.The results showed that the SVM algorithm is the best model for predicting the optimal timing for SAVR and for predicting the post-surgery survival period.By optimizing the timing of SAVR surgery using the SVM algorithm,we observed a significant improvement in the survival period after SAVR.Our study demonstrates that ML algorithms generate reliable models for predicting the optimal timing of SAVR in asymptomatic patients with moderate-to-severe AS.

Importance of concomitant functional mitral regurgitation on survival in severe aortic stenosis patients undergoing aortic valve replacement

BACKGROUND Mitral regurgitation(MR)is commonly seen in patients with severe aortic stenosis(AS)undergoing aortic valve replacement(AVR).But the long-term implications of MR in AS are unknown.AIM To investigate MR’s impact on survival of patients undergoing surgical AVR for severe AS.METHODS Of the 740 consecutive patients with severe AS evaluated between 1993 and 2003,287 underwent AVR forming the study cohort.They were followed up to death or till the end of 2019.Chart reviews were performed for clinical,echocardiographic,and therapeutic data.MR was graded on a 1-4 scale.Mortality data was obtained from chart review and the Social Security Death Index.Survival was analyzed as a function of degree of MR.RESULTS The mean age of the severe AS patients who had AVR(n=287)was 72±13 years,46%women.Over up to 26 years of follow up,there were 201(70%)deaths,giving deep insights into the determinants of survival of severe AS who had AVR.The 5,10 and 20 years survival rates were 75%,45%and 25%respectively.Presence of MR was associated with higher mortality in a graded fashion(P=0.0003).MR was significantly associated with lower left ventricular(LV)ejection fraction and larger LV size.Impact of MR on mortality was partially mediated through lower LV ejection fraction and larger LV size.By Cox regression,MR,lower ejection fraction(EF)and larger LV end-systolic dimension were independent predictors of higher mortality(χ^(2)=33.2).CONCLUSION Presence of greater than 2+MR in patients with severe AS is independently associated with reduced survival in surgically managed patients,an effect incremental to reduced EF and larger LV size.We suggest that aortic valve intervention should be considered in severe AS patients when>2+MR occurs irrespective of EF or symptoms.

Outcomes of Self-Expanding Transcatheter Pulmonary Valves:Extended Follow-Up of a Prospective Trial

Background:The Venus-P valve was the first self-expanding valve used world-wide for transcatheter pulmonary valve replacement(TPVR)in patients with severe pulmonary regurgitation(PR).We intended to report the extended follow-up results from the prospective trial(No.NCT02590679).Methods:A total of 38 patients with severe PR(mean age 24.2±13.2)were included.Follow-up data were obtained after implanted at 1,6,and 12 months and yearly after.The frame geometry was assessed on post-implant computer tomography(CT)scanning by calculating the non-circularity[circularity ratio(minimum diameter/maximum diameter)<0.9]and under-expansion[expansion ratio(derived external valve area/nominal external valve area)<0.9).Adverse events(all-cause mortality,reintervention,valve dysfunction,stent fracture and endocarditis)were recorded.Results:All valves were implanted successfully with normal function at discharge.Geometric CT analysis showed underexpanded valve was detected in 22 patients(63%)and non-circular valve was seen in 16 patients(46%).During a median follow-up of 4.8 years(range 0.3-8.1),there were 1 death and 1 surgical explant,both resulting from endocarditis.Five-year freedom from valve dysfunction and stent fracture were 84.8%(95%CI 74.8-94.7)and 83.5%(95%CI 73.8-93.2).Endocarditis occurred in 3 patients at a median time of 7 months.Stent fracture was more common in patients with non-circularity stents.Conclusion:TPVR using Venus-P valve is associated with favorable outcomes at 5 years.Non-circular shapes in the valve level may have a higher risk of stent fracture.

Prediction of permanent pacemaker implantation after transcatheter aortic valve replacement:The role of machine learning

BACKGROUND Atrioventricular block requiring permanent pacemaker(PPM)implantation is an important complication of transcatheter aortic valve replacement(TAVR).Application of machine learning could potentially be used to predict preprocedural risk for PPM.AIM To apply machine learning to be used to predict pre-procedural risk for PPM.METHODS A retrospective study of 1200 patients who underwent TAVR(January 2014-December 2017)was performed.964 patients without prior PPM were included for a 30-d analysis and 657 patients without PPM requirement through 30 d were included for a 1-year analysis.After the exclusion of variables with near-zero variance or≥50%missing data,167 variables were included in the random forest gradient boosting algorithm(GBM)optimized using 5-fold cross-validations repeated 10 times.The receiver operator curve(ROC)for the GBM model and PPM risk score models were calculated to predict the risk of PPM at 30 d and 1 year.RESULTS Of 964 patients included in the 30-d analysis without prior PPM,19.6%required PPM post-TAVR.The mean age of patients was 80.9±8.7 years.42.1%were female.Of 657 patients included in the 1-year analysis,the mean age of the patients was 80.7±8.2.Of those,42.6%of patients were female and 26.7%required PPM at 1-year post-TAVR.The area under ROC to predict 30-d and 1-year risk of PPM for the GBM model(0.66 and 0.72)was superior to that of the PPM risk score(0.55 and 0.54)with a P value<0.001.CONCLUSION The GBM model has good discrimination and calibration in identifying patients at high risk of PPM post-TAVR.

Delayed Coronary Ostial Stenosis after Surgical Aortic Valve Replacement and Root Enlargement Treated with Beating Heart On-Pump CABG

Coronary ostial stenosis after surgical aortic valve replacement (SAVR) is a rare but potentially fatal complication. Surgeons must have a high level of vigilance regarding the presentation of acute myocardial ischemia, arrhythmia, and heart failure after AVR. According to most reports, this event can be time-dependent divided into two groups;early acute phase that mostly happens intraoperative during weaning of CPB or in early ICU stay, and late presentation usually appears 1 - 6 months post surgery. Here, we describe an unusual subacute presentation of right coronary ostial stenosis 12 days after SAVR, which was treated successfully with redo beating heart coronary artery bypass grafting (CABG).

Safety and effectiveness of neuromuscular electrical stimulation in cardiac surgery:A systematic review

BACKGROUND Lack of mobilization and prolonged stay in the intensive care unit(ICU)are major factors resulting in the development of ICU-acquired muscle weakness(ICUAW).ICUAW is a type of skeletal muscle dysfunction and a common complication of patients after cardiac surgery,and may be a risk factor for prolonged duration of mechanical ventilation,associated with a higher risk of readmission and higher mortality.Early mobilization in the ICU after cardiac surgery has been found to be low with a significant trend to increase over ICU stay and is also associated with a reduced duration of mechanical ventilation and ICU length of stay.Neuromuscular electrical stimulation(NMES)is an alternative modality of exercise in patients with muscle weakness.A major advantage of NMES is that it can be applied even in sedated patients in the ICU,a fact that might enhance early mobilization in these patients.AIM To evaluate safety,feasibility and effectiveness of NMES on functional capacity and muscle strength in patients before and after cardiac surgery.METHODS We performed a search on Pubmed,Physiotherapy Evidence Database(PEDro),Embase and CINAHL databases,selecting papers published between December 2012 and April 2023 and identified published randomized controlled trials(RCTs)that included implementation of NMES in patients before after cardiac surgery.RCTs were assessed for methodological rigor and risk of bias via the PEDro.The primary outcomes were safety and functional capacity and the secondary outcomes were muscle strength and function.RESULTS Ten studies were included in our systematic review,resulting in 703 participants.Almost half of them performed NMES and the other half were included in the control group,treated with usual care.Nine studies investigated patients after cardiac surgery and 1 study before cardiac surgery.Functional capacity was assessed in 8 studies via 6MWT or other indices,and improved only in 1 study before and in 1 after cardiac surgery.Nine studies explored the effects of NMES on muscle strength and function and,most of them,found increase of muscle strength and improvement in muscle function after NMES.NMES was safe in all studies without any significant complication.CONCLUSION NMES is safe,feasible and has beneficial effects on muscle strength and function in patients after cardiac surgery,but has no significant effect on functional capacity.

Trans-Frame Aortic Regurgitation of New-Generation Aortic Bioprosthesis

A widely used aortic valve bioprosthesis is susceptible to regurgitation between the sewing ring and the frame of the valve due to its relatively thin fabric coverage. In some cases this leak has been shown to resolve with administration of protamine, however, tension on this area from annular sutures placed in an asymmetric bicuspid valve annulus may exacerbate the defect.

Combined Low-dose Aspirin and Warfarin Anticoagulant Therapy of Postoperative Atrial Fibrillation Following Mechanical Heart Valve Replacement

The safety and efficacy of combined low dose aspirin and warfarin therapy in patients with atrial fibrillation after mechanical heart valve replacement were evaluated. A total of 1016 patients （620 females, mean age of 36.8-4-7.7 years） admitted for cardiac valve replacement and complicated with atrial fibrillation after surgery were randomly divided into study （warfarin plus 75-100 mg aspirin） or control （warfarin only） groups. International normalized ratio （INR） and prothrombin time were main- tained at 1.8-2.5 and 1.5-2.0 times the normal values, respectively. Thromboembolic events and major bleedings were registered during the follow-up period. Patients were followed up for 24±9 months. The average dose of warfarin in the study and control groups was 2.91±0.83 mg and 2.88±0.76 mg, respec- tively （P〉0.05）. The incidence of overall thromboembolic events in study group was lower than that in control group （2.16% vs. 4.35%, P=0.049）. No statistically significant differences were found in hem- orrhage events （3.53% vs. 3.95%, P=-0.722） or mortality （0.20% vs. 0.40%, P=0.559） between the two groups. Combined low dose aspirin and warfarin therapy in the patients with atrial fibrillation following mechanical heart valve replacement significantly decreased thromboembolic events as compared with warfarin therapy alone. This combined treatment was not associated with an increase in the risk of major bleeding or mortality.

Bioprosthetic Valve Size Selection to Optimize Aortic Valve ReplacementSurgical Outcome: A Fluid-Structure Interaction Modeling Study

Aortic valve replacement(AVR)remains a major treatment option for patients with severe aortic valve disease.Clinical outcome of AVR is strongly dependent on implanted prosthetic valve size.Fluid-structure interaction(FSI)aortic root models were constructed to investigate the effect of valve size on hemodynamics of the implanted bioprosthetic valve and optimize the outcome of AVR surgery.FSI models with 4 sizes of bioprosthetic valves(19(No.19),21(No.21),23(No.23)and 25 mm(No.25))were constructed.Left ventricle outflow track flow data from one patient was collected and used as model flow conditions.Anisotropic Mooney–Rivlin models were used to describe mechanical properties of aortic valve leaflets.Blood flow pressure,velocity,systolic valve orifice pressure gradient(SVOPG),systolic cross-valve pressure difference(SCVPD),geometric orifice area,and flow shear stresses from the four valve models were compared.Our results indicated that larger valves led to lower transvalvular pressure gradient,which is linked to better post AVR outcome.Peak SVOPG,mean SCVPD and maximum velocity for Valve No.25 were 48.17%,49.3%,and 44.60%lower than that from Valve No.19,respectively.Geometric orifice area from Valve No.25 was 52.03%higher than that from Valve No.19(1.87 cm2 vs.1.23 cm2).Implantation of larger valves can significantly reduce mean flow shear stress on valve leaflets.Our initial results suggested that larger valve size may lead to improved hemodynamic performance and valve cardiac function post AVR.More patient studies are needed to validate our findings.

Effect of L-carnitine on Cardiomyocyte Apoptosis and Cardiac Function in Patients Undergoing Heart Valve Replacement Operation

Summary： The effects of L-carnitine, as an ingredient of cardioplegia solution, on cardiac function and cardiomyocyte apoptosis in patients undergoing heart valve replacement operation were investigated. Twenty-three cases undergoing heart valve replacement with cardiopulmonary bypass （CPB） were randomly allocated into two groups： L-carnitine group （n=12, 12 g/L L-carnitine was put in the ST. Thomas cardioplegia） and control group （n=11, identical to the L-carnitine group except that normal saline was administered instead of L-carnitine）. Serum cardial troponin I （cTnI） levels, the left ventricular ejection fraction （LVEF）, and cardiac index （CI） were measured perioperatively. A bit of myocardial tissue obtained from right atria was taken before CPB and by the end of intracardiac procedure to undergo electron microscopy examination and estimate apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL）. From the end of CPB to 3 days after operation, the serum levels of cTnI in the L-carnitine group was significantly lower than that in the control group （P〈0.05）. Heart color ultrasonogram showed that the CI index and LVEF at 7th day postoperatively in the L-carnitine group were significantly higher than in the control group （P〈0.05）. Compared to the control group, L-carnitine significantly alleviated the morphologic changes of cardiac muscle cells （electron microscopy examination） and decreased the amounts of apoptotic cardiac muscle cells （TUNEL）. Furthermore, the dosage of vasoactive drugs used after operation was significantly less in the L-carnitine group （P〈0.01）. It was concluded that L-carnitine cardioplegia solution could improve cardiac function in patients undergoing heart valve replacement operation and alleviate CPB-mediated apoptosis of cardiac muscle cells.

Risk scoring model for prediction of non-home discharge after transcatheter aortic valve replacement

Background Patients undergoing transcatheter aortic valve replacement(TAVR) are likely to be discharged to a location other than home. We aimed to determine the association between preoperative risk factors and non-home discharge after TAVR. Methods Patients discharged alive after TAVR at three centers were identified from a prospectively maintained database randomly divided into 80% derivation and 20% validation cohorts. Logistic regression models were fit to identify preoperative factors associated with non-home discharge in the derivation cohort. Multivariable models were developed and a nomogram based risk-scoring system was developed for use in preoperative counseling. Results Between June 2012 and December 2018, a total of 1,163 patients had TAVR at three centers. Thirty-seven patients who died before discharge were excluded. Of the remaining 1,126 patients(97%) who were discharged alive, the incidence of non-home discharge was 25.6%(n = 289). The patient population was randomly divided into the 80%(n = 900) derivation cohort and 20%(n = 226) validation cohort. Mean ± SD age of the study population was 83 ± 8 years. In multivariable analysis, factors that were significantly associated with non-home discharge were extreme age, female sex, higher STS scores, use of general anesthesia, elective procedures, chronic liver disease, non-transfemoral approach and postoperative complications. The unbiased estimate of the C-index was 0.81 and the model had excellent calibration. Conclusions One out of every four patients undergoing TAVR is discharged to a location other than home. Identification of preoperative factors associated with non-home discharge can assist patient counseling and postoperative disposition planning.

A meta-analysis of 1-year outcomes of transcatheter versus surgical aortic valve replacement in low-risk patients with severe aortic stenosis

Background Transcatheter aortic valve replacement(TAVR)for the treatment symptomatic severe aortic stenosis(AS)is indicated in patients with intermediate or higher surgical risk.Latest trials showed TAVR,and surgical aortic valve replacement(SAVR)perform similarly at 1-year for the composite outcomes of mortality,stroke and rehospitalization.We performed a comprehensive meta-analysis to compare individual outcomes at 1-year for TAVR compared to SAVR in low-risk patients.Methods Pub Med,Embase,and Cochrane central were searched for all the randomized controlled trials(RCTs)that reported 1-year comparative outcomes of TAVR and surgical aortic valve replacement(SAVR).Our conclusions are based upon the random-effects model using Der Simonian-Laird estimator.Results Data from 4 trials and 2887 randomized patients showed that TAVR had lower rates of all-cause mortality,cardiovascular mortality,and atrial fibrillation compared to SAVR at 1-year follow-up(P<0.05 for all).Also,TAVR was also associated with a significantly higher risk of permanent pacemaker implantation and moderate-severe paravalvular leak(P<0.05).Conclusions The latest randomised trial data demonstrates that in short-term,TAVR is safe and effective in reducing all-cause mortality or stroke.Longer follow-up of RCTs is needed to determine the durability of clinical benefits in TAVR over SAVR in low-risk patients.

Measuring frailty in patients with severe aortic stenosis:a comparison of the edmonton frail scale with modified fried frailty assessment in patients undergoing transcatheter aortic valve replacement

Frailty is generally defined as a clinical syndrome of decreased physiologic reserve which drives to increased vulnerability and susceptibility to different stressors together with poor recovery to homeostasis.[1]The relevance of frailty status in a wide range of prospective cohorts is mostly related to an increasing burden in both mortality,hospital readmissions,disability,and falls.

Clinical results of tricuspid valve replacement—a 21-case report

Objective： To summarize the clinical experiences of 21 patients treated with tricuspid valve replacement （TVR） and investigate the surgical indications and methods. Methods： Data from 21 patients who underwent TVR from December 2002 to March 2009 were retrospectively collected and analyzed. The mean age was 48.86± 15.37 years （range： 20-72 years）. The underlying disease of the patients was classified as rheumatic （n = 10）, congenital （n = 8）, endocarditis （n = 2） or chest trauma （n = 1）. Previous cardiac surgery had been performed in 12 patients （57.14%）. Results： In-hospital death occurred in two patients （9.52%）. Postoperative morbidities included cardiac failure （n = 2）, bleeding related re-operation （n = 1）, and plural effusion （n = 2）. Conclusion： The early outcomes of TVR were acceptable. At the present time TVR can be performed through optimal perioperative management.