Survival following a concomitant aortic valve procedure during left ventricular assist device surgery: an ISHLT Mechanically Assisted Circulatory Support (IMACS) Registry analysis

Prosthetic Valve Fate in Patients With Continuous-Flow Left Ventricular Assist Devices

Prosthetic valve-related morbidity and mortality in patients with left ventricular assist devices (LVADs) remain unclear. We retrospectively reviewed patients who received a HeartMate II or 3 LVAD at our center between April 2004 and December 2022. Patients with a valve prosthesis in any position were included. Of the 726 LVAD recipients, 74 (10.2%) underwent valve replacement before (n = 37, 50.0%), concomitantly with (n = 32, 43.2%), or after (n = 6, 8.1%) LVAD insertion. Prosthetic valves were implanted in the aortic (n = 32), mitral (n = 23), and tricuspid (n = 26) positions. Mechanical valves were present in eight (three aortic, five mitral) patients. At a median follow-up of 1.97 years post-VAD (interquartile range [IQR]: 0.56-4.58 years), there was one valve-related death due to severe aortic bioprosthetic insufficiency. Five of 28 (17.9%) patients with an aortic bioprosthesis had evidence of dysfunction on follow-up echocardiography. Median time to first sign of aortic bioprosthetic valve dysfunction was 1 (IQR: 0.6-5.1) year from time of LVAD with the prosthesis in place and 10.8 (IQR: 9.5-12.6) years from date of initial valve insertion. Prosthetic valve-related mortality or reinterventions are uncommon in patients with LVADs; however, bioprosthetic aortic valve dysfunction can develop less than 1 year after LVAD implantation.

Aortic regurgitation in left ventricular assist device patients: Does aortic root dilatation contribute to valve incompetence?

BACKGROUND

Aortic regurgitation (AR) is a known complication after left ventricular assist device (LVAD) implantation potentially leading to recurrent heart failure. Possible pathomechanisms include valvular pathologies and aortic root dilatation. We assessed aortic root dimensions in a group of consecutive LVAD patients who received HeartMate 3.

METHODS

Since 11/2015, we identified 68 patients with no or mild AR at the time of HeartMate 3 implantation who underwent serial echocardiography to assess AR and aortic root dimensions (annulus, sinus, and sinotubular junction). Median follow-up was 40 months (2-94 months). Results were correlated with clinical outcomes.

RESULTS

Patients were 60 ± 10 years old, predominantly male (88%) and 35% presented in preoperative critical condition as defined by INTERMACS levels 1 and 2. During follow-up, 23 patients developed AR ≥ II (34%). Actuarial incidence was 8% at 1 year, 29% at 3 years and 41% at 5 years. Echocardiography revealed practically stable root dimensions at the latest follow-up compared to the preoperative state (annulus: 23 ± 3 mm vs. 23 ± 2 mm, sinus: 32 ± 4 mm vs. 33 ± 3 mm, sinotubular junction: 27 ± 3 mm vs. 28 ± 3 mm), irrespective of the development of AR. Serial CT angiograms were performed in 13 patients to confirm echocardiographic findings. Twenty-one patients died during LVAD support leading to a 5-year survival of 71%, showing no difference between patients with and without AR ≥ II (p = 0.573).

CONCLUSIONS

At least moderate AR develops over time in a substantial fraction of patients (one-third over 3 years). The mechanism does not seem to be related to dilatation of the aortic annulus or root.

Aortic insufficiency in the patient on contemporary durable left ventricular assist device support: A state-of-the-art review on preoperative and postoperative assessment and management

The development of aortic insufficiency (AI) during HeartMate 3 durable left ventricular assist device (dLVAD) support can lead to ineffective pump output and recurrent heart failure symptoms. Progression of AI often comingles with the occurrence of other hemodynamic-related events encountered during LVAD support, including right heart failure, arrhythmias, and cardiorenal syndrome. While data on AI burdens and clinical impact are still insufficient in patients on HeartMate 3 support, moderate or worse AI occurs in approximately 8% of patients by 1 year and studies suggest AI continues to progress over time and is associated with increased frequency of right heart failure. The first line intervention for AI management is prevention, undertaking surgical intervention on the insufficient valve at the time of dLVAD implant and avoiding excessive device flows and hypertension during long-term support. Device speed augmentation may then be undertaken to try and overcome the insufficient lesion, but the progression of AI should be anticipated over the long term. Surgical or transcatheter aortic valve interventions may be considered in dLVAD patients with significant persistent AI despite medical management, but neither intervention is without risk. It is imperative that future studies of dLVAD support capture AI in clinical end-points using uniform assessment and grading of AI severity by individuals trained in AI assessment during dLVAD support.

Management of aortic valve insufficiency in patients with continuous-flow left ventricular assist device: a republication of the review published in Japanese Journal of Artificial Organs

Since 2011, implantable ventricular assist devices have been a standard treatment for severe heart failure alongside heart transplantation in Japan. However, the limited availability of donors has led to a prolonged wait for transplants, now averaging 1719 days, intensifying the issue of aortic insufficiency in patients with continuous flow ventricular assist devices. These devices limit the opening of the aortic valve, leading to sustained closure and increased shear stress, which accelerates valve degradation. Risk factors for aortic insufficiency include having a smaller body surface area, being of advanced age, and the presence of mild aortic insufficiency prior to device implantation. In patients presenting with mild or moderate aortic regurgitation at the time of ventricular assist device implantation, interventions such as aortic valve repair or bioprosthetic valve replacement are performed with the aim of halting its progression. The choice of surgical procedure should be tailored to each patient's individual condition. The management of de novo aortic insufficiency in patients with continuous flow ventricular assist devices remains challenging, with no clear consensus on when to intervene. Interventions for significant aortic insufficiency typically consider the patient's symptoms and aortic insufficiency severity. De novo aortic insufficiency progression in continuous flow ventricular assist devices patients necessitates careful monitoring and intervention based on individual patient assessments and valve condition. This review was created based on a translation of the Japanese review written in the Japanese Journal of Artificial Organs in 2023 (Vol. 52, No. 1, pp. 77-80), with some modifications.

Safety and efficacy of aortic valvuloplasty for de novo aortic insufficiency in patients with a left-ventricular assist device

OBJECTIVES

Progression of aortic insufficiency during left-ventricular assist device (LVAD) support is a crucial topic. One treatment option is aortic valvuloplasty (AVP); however, there is controversy regarding its safety and efficacy. We investigated the safety and efficacy of AVP using the coaptation stitch method (Park's stitch) performed for de novo aortic insufficiency.

METHODS

Between 2013 and 2020, 175 consecutive patients underwent LVAD implantation, of which 7 patients [men, 2 (28.6%); median age, 55 years] underwent late-stage AVP. Two patients underwent AVP within 2 weeks, and the remaining six patients underwent AVP 3, 19, 24, 28, 42, and 49 months, respectively, after LVAD implantation.

RESULTS

Preoperatively, the degree of aortic insufficiency was moderate in 6 (85.7%) patients and severe in 1 (14.3%) patient. AVP was technically successful in 6 (85.7%) patients, while one case of failed plasty was subsequently treated with bioprosthetic valve replacement. A 1-year post-AVP right heart catheterization study revealed a median pulmonary artery wedge pressure of 10.0 mmHg. No deaths or heart failure admissions occurred during the follow-up (median, 38.0 months). There was no aortic insufficiency in 2 (28.6%) patients; however, trivial AI was observed in 3 (42.8%) patients, and mild AI was observed in 1 (14.3%) patient 2 years postoperatively. However, at the 3-year follow-up, two patients developed an increase in AI grade from trivial to mild.

CONCLUSIONS

AVP using Park's stitch was safe. It is critical to carefully observe the aortic valve during AVP surgery to ensure that AVP is appropriate.

Development of early prediction model of in-hospital cardiac arrest based on laboratory parameters

BACKGROUND

In-hospital cardiac arrest (IHCA) is an acute disease with a high fatality rate that burdens individuals, society, and the economy. This study aimed to develop a machine learning (ML) model using routine laboratory parameters to predict the risk of IHCA in rescue-treated patients.

METHODS

This retrospective cohort study examined all rescue-treated patients hospitalized at the First Medical Center of the PLA General Hospital in Beijing, China, from January 2016 to December 2020. Five machine learning algorithms, including support vector machine, random forest, extra trees classifier (ETC), decision tree, and logistic regression algorithms, were trained to develop models for predicting IHCA. We included blood counts, biochemical markers, and coagulation markers in the model development. We validated model performance using fivefold cross-validation and used the SHapley Additive exPlanation (SHAP) for model interpretation.

RESULTS

A total of 11,308 participants were included in the study, of which 7779 patients remained. Among these patients, 1796 (23.09%) cases of IHCA occurred. Among five machine learning models for predicting IHCA, the ETC algorithm exhibited better performance, with an AUC of 0.920, compared with the other four machine learning models in the fivefold cross-validation. The SHAP showed that the top ten factors accounting for cardiac arrest in rescue-treated patients are prothrombin activity, platelets, hemoglobin, N-terminal pro-brain natriuretic peptide, neutrophils, prothrombin time, serum albumin, sodium, activated partial thromboplastin time, and potassium.

CONCLUSIONS

We developed a reliable machine learning-derived model that integrates readily available laboratory parameters to predict IHCA in patients treated with rescue therapy.

Managing valvular pathology during LVAD implantation

Since the time of their invention, implantable continuous flow left ventricular assist devices (LVADs) have improved the quality of life and extended survival for patients with advanced heart failure. The decision surgeons and their physician colleagues make with these patients to undergo implantation must come with full understanding of the immediate, short-term, and long-term implications of such a life-changing procedure. The presence of pathology regarding the aortic, mitral, and tricuspid valves introduces particularly complex problems for the surgical treatment strategy. Concomitant valve repair or replacement increases cardiopulmonary bypass and cross clamp times, and could potentially lead to worse outcomes in the perioperative setting. Following perioperative recovery, valvular pathology may worsen or arise de novo given the often drastic immediate physiologic changes in blood flow, septal function, and, over time, ventricular remodeling. Over the past two decades, there has been vast improvement in the device manufacturing, surgical techniques, and medical management surrounding LVAD implantation. Yet, addressing concomitant valvular pathology remains a complex question with no perfect solutions. This review aims to briefly describe the evolution of approach to valvular pathology in the LVAD patient and offer our opinion and treatment rationale.

Outcomes of concomitant aortic valve procedures and left ventricular assist device implantation: A systematic review and meta-analysis

BACKGROUND

Left ventricular assist device (LVAD) implantation is frequently employed in patients with end-stage heart failure. The outcomes of addressing the repair of all substantial aortic valvular disease at the time of LVAD implantation remain unclear. We sought to assess the clinical outcomes in patients undergoing LVAD implantation concomitant with aortic valve procedures (AVPs) compared with isolated LVAD implantation.

METHODS

A literature search was performed using PubMed, Embase, and Cochrane library from inception till June 2022. Primary outcomes included short-term mortality and long-term survival. Random effects models were used to compute mean differences and odds ratios with 95% confidence intervals (CIs).

RESULTS

A total of 14 observational studies (N = 52 693) met our inclusion criteria. Concomitant LVAD implantation and AVPs were associated with higher short-term mortality (OR = 1.61 [95% CI, 1.06-2.42]; p = 0.02) and mean CPBt (MD = 43.25 [95% CI, 22.95-63.56]; p < 0.0001), and reduced long-term survival (OR = 0.70 [95% CI, 0.55-0.88]; p = 0.003) compared with isolated LVAD implantation. No difference in the odds of cerebrovascular accident (OR = 1.05 [95% CI, 0.79-1.39]; p = 0.74) and mean length of hospital stay (MD = 2.89 [95% CI, -4.04 to 9.82]; p = 0.41) was observed between the two groups. On adjusted analysis, short-term mortality was significantly higher in the LVAD group with concurrent AVPs when compared with the isolated LVAD group (aHR = 1.50 [95% CI, 1.20-1.87]; p = 0.0004).

CONCLUSIONS

Concurrent AVPs were associated with higher short-term mortality and reduced long-term survival in patients undergoing LVAD implantation compared with isolated LVAD implantation.

Considerations of valvular heart disease in children with ventricular assist devices

Ventricular assist devices have become a valuable tool in the treatment of heart failure in children. The use of ventricular assist devices has decreased mortality in children with end-stage heart failure awaiting transplant. It is not uncommon for children with end-stage heart failure associated with cardiomyopathy or congenital heart disease to have significant systemic semilunar and atrioventricular valve regurgitation, which can impact the efficiency and efficacy of hemodynamic support provided by a ventricular assist device. Therefore, implanting clinicians should carefully assess for valve abnormalities that may need repair and impact device selection and cannulation strategy to effectively support this diverse population. The purpose of this review is to provide an overview of this important and relevant topic and to discuss strategies for managing these patients.

Aortic valve disorders and left ventricular assist devices

Aortic valve disorders are important considerations in advanced heart failure patients being evaluated for left ventricular assist devices (LVAD) and those on LVAD support. Aortic insufficiency (AI) can be present prior to LVAD implantation or develop de novo during LVAD support. It is usually a progressive disorder and can lead to impaired LVAD effectiveness and heart failure symptoms. Severe AI is associated with worsening hemodynamics, increased hospitalizations, and decreased survival in LVAD patients. Diagnosis is made with echocardiographic, device assessment, and/or catheterization studies. Standard echocardiographic criteria for AI are insufficient for accurate diagnosis of AI severity. Management of pre-existing AI includes aortic repair or replacement at the time of LVAD implant. Management of de novo AI on LVAD support is challenging with increased risks of repeat surgical intervention, and percutaneous techniques including transcatheter aortic valve replacement are assuming greater importance. In this manuscript, we provide a comprehensive approach to contemporary diagnosis and management of aortic valve disorders in the setting of LVAD therapy.

Concomitant or late aortic valve intervention and its efficacy for aortic insufficiency associated with continuous-flow left ventricular assist device implantation

Moderate to severe aortic insufficiency (AI) in patients who underwent continuous-flow left ventricular assist device (CF-LVAD) implantation is a significant complication. According to the INTERMACS registry analysis, at least mild AI occurs in 55% of patients at 6 months after CF-LVAD implantation and moderate to severe AI is significantly associated with higher rates of re-hospitalization and mortality. The clinical implications of these data may underscore consideration of prophylactic aortic valve replacement, or repair, at the time of CF-LVAD implantation, particularly with expected longer duration of support and in patients with preexisting AI that is more than mild. More crucially, even if a native aortic valve is seemingly competent at the time of VAD implantation, we frequently find de novo AI as time goes by, potentially due to commissural fusion in the setting of inconsistent aortic valve opening or persistent valve closure caused by CF-LVAD support, that alters morphological and functional properties of innately competent aortic valves. Therefore, close monitoring of AI is mandatory, as the prognostic nature of its longitudinal progression is still unclear. Clearly, significant AI during VAD support warrants surgical intervention at the appropriate timing, especially in patients of destination therapy. Nonetheless, such an uncertainty in the progression of AI translates to a lack of consensus regarding the management of this untoward complication. In practice, proposed surgical options are aortic valve replacement, repair, closure, and more recently transcatheter aortic valve implantation or closure. Transcatheter approach is of course less invasive, however, its efficacy in terms of long-term outcome is limited. In this review, we summarize the recent evidence related to the pathophysiology and surgical treatment of AI associated with CF-LVAD implantation.

A year in heart failure: an update of recent findings

Major changes have occurred in these last years in heart failure (HF) management. Landmark trials and the 2021 European Society of Cardiology guidelines for the diagnosis and treatment of HF have established four classes of drugs for treatment of HF with reduced ejection fraction: angiotensin-converting enzyme inhibitors or an angiotensin receptor-neprilysin inhibitor, beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose co-transporter 2 inhibitors, namely, dapagliflozin or empagliflozin. These drugs consistently showed benefits on mortality, HF hospitalizations, and quality of life. Correction of iron deficiency is indicated to improve symptoms and reduce HF hospitalizations. AFFIRM-AHF showed 26% reduction in total HF hospitalizations with ferric carboxymaltose vs. placebo in patients hospitalized for acute HF (P = 0.013). The guanylate cyclase activator vericiguat and the myosin activator omecamtiv mecarbil improved outcomes in randomized placebo-controlled trials, and vericiguat is now approved for clinical practice. Treatment of HF with preserved ejection fraction (HFpEF) was a major unmet clinical need until this year when the results of EMPEROR-Preserved (EMPagliflozin outcomE tRial in Patients With chrOnic HFpEF) were issued. Compared with placebo, empagliflozin reduced by 21% (hazard ratio, 0.79; 95% confidence interval, 0.69 to 0.90; P < 0.001), the primary outcome of cardiovascular death or HF hospitalization. Advances in the treatment of specific phenotypes of HF, including atrial fibrillation, valvular heart disease, cardiomyopathies, cardiac amyloidosis, and cancer-related HF, also occurred. Coronavirus disease 2019 (COVID-19) pandemic still plays a major role in HF epidemiology and management. All these aspects are highlighted in this review.

Contemporary contribution of cardiac surgery for the treatment of cardiomyopathies and pericardial diseases

Cardiomyopathy refers to a spectrum of heterogeneous myocardial disorders characterized by morphological and structural alterations leading eventually to heart failure, by affecting cardiac filling and/or the cardiac systolic function. Heart transplantation is currently the gold standard surgical treatment for patients with heart failure, with a median survival in adults of 12 years according to international registries. However, the limited available donor pool does not allow its extensive employment. For this reason, mechanical circulatory supports are increasingly used, and in the short term are becoming as possible alternatives to heart transplantation, owing to improved technologies and increased biocompatibility. However, long-term outcomes of mechanical assist devices are still burdened with a high rate of adverse events. Conventional surgical treatments could be still considered as alternatives to heart replacement treatment when tailored both on patient clinical conditions and etiology of cardiac diseases. In particular, among patients affected by ischemic cardiomyopathy, coronary artery bypass grafting has proven to improve survival when associated to optimal medical treatment, and surgical ventricular restoration might be considered as a valid treatment in particular cases. Correction of functional mitral valve regurgitation by mitral annuloplasty, which aims to restore left ventricular geometry, has not demonstrated unambiguous results, and outcomes of this procedure are still controversial. Pericardial pathology becomes of surgical interest when it is responsible for a reduced filling capacity of the heart chambers, which can develop acutely (cardiac tamponade) or chronically (as in the case of constrictive pericarditis). This review focuses on the different surgical approaches that could be adopted to treat patients with heart failure and pericardial diseases.

Less-invasive ventricular assist device implantation: A multicenter study

BACKGROUND

Left ventricular assist device has been shown to be a safe and effective treatment option for patients with end-stage heart failure. However, there is limited evidence showing the effect of the implantation approach on postoperative morbidities and mortality. We aimed to compare left ventricular assist device implantation using conventional sternotomy versus less-invasive surgery including hemi-sternotomy and the minithoracotomy approach.

METHODS

Between January 2014 and December 2018, 342 consecutive patients underwent left ventricular assist device implantation at 2 high-volume centers. Patient characteristics were prospectively collected. The propensity score method was used to create 2 groups in a 1:1 fashion. A competing risk regression model was used to evaluate time to death adjusting for competing risk of heart transplantation.

RESULTS

The unmatched cohort included 241 patients who underwent left ventricular assist device implantation with the conventional sternotomy technique and 101 patients who underwent left ventricular assist device implantation with the less-invasive surgery technique. Propensity matching produced 2 groups each including 73 patients. In the matched groups, reexploration rate for bleeding was necessary in 17.9% (12/67) in the conventional sternotomy group compared with 4.1% (3/73) the less-invasive surgery group (P = .018). Intensive care unit stay for the less-invasive surgery group was significantly lower than for the sternotomy group (10.5 [interquartile range, 2-25.75] days vs 4 [interquartile range, 2-9.25] days, P = .008), as was hospital length of stay (37 [interquartile range, 27-61] days vs 25.5 [interquartile range, 21-42] days, P = .007). Mortality cumulative incidence for conventional surgery was 24% (95% confidence interval, 14.3-34.8) at 1 year and 26% (95% confidence interval, 15.9-37.4) at 2 years for patients without heart transplantation. Mortality cumulative incidence for less-invasive surgery was 22.5% (95% confidence interval, 12.8-33.8) at 1 year and 25.2% (95% confidence interval, 14.5-37.4) at 2 years for patients without heart transplantation. There was no difference in cumulative mortality incidence when adjusting for competing risk of heart transplantation (subdistribution hazard, 0.904, 95% confidence interval, 0.45-1.80, P = .77).

CONCLUSIONS

The less-invasive surgery approach is a safe technique for left ventricular assist device implantation. Less-invasive surgery was associated with a significant reduction in the postoperative bleeding complications and duration of hospital stay, with no significant difference in mortality incidence.