Expert Consensus Paper: Lateral Thoracotomy for Centrifugal Ventricular Assist Device Implant

Durable left ventricular assist devices as a bridge to transplantation: what to expect along the way?

INTRODUCTION

The scarcity of donors coupled with the improvements in left ventricular assist devices (LVAD) technology has led to the use of LVAD as a bridge to transplantation (BTT).

AREAS COVERED

The authors provide an overview of the current status of LVAD BTT implantation with special focus ranging from patient selection and pre-implantation optimization to post-transplant outcomes.

EXPERT OPINION

The United Network for Organ Sharing 2018 policy amendment resulted in a significant reduction in the number of LVADs used for BTT in the US. To overcome this issue, modifications in the US allocation policy to consider factors such as days on device support, age, and type of complications may be necessary to potentially increase implantation rates.

Less is better? Comparing effects of median sternotomy and thoracotomy surgical approaches for left ventricular assist device implantation on postoperative outcomes and valvulopathy

OBJECTIVE

Our objective was to compare outcomes after left ventricular assist device implantation performed via median sternotomy or lateral thoracotomy.

METHODS

We retrospectively analyzed 222 adult patients with the HeartMate3 (Abbott Lab) left ventricular assist device implanted between November 2014 and November 2021. Outcomes stratified by surgical approach were evaluated in propensity score-matched groups. The primary outcome was 1-year survival. Secondary outcomes included in-hospital morbidity and mortality, readmissions, and significant valvular regurgitation.

RESULTS

Our cohort consisted of 60 patients (27%) who underwent lateral thoracotomy and 162 patients (73%) who underwent median sternotomy. Propensity score matching compared 45 patients who underwent lateral thoracotomy with 68 patients who underwent median sternotomy. There were no differences in intensive care unit or hospital stay duration (median, 10 vs 11 days, P = .58; 46 vs 40 days, P = .279), time to extubation (median, 2 days, P = .627), vasoactive-inotropic scores at intensive care unit arrival (18.20 vs 16.60, P = .654), or in-hospital mortality (2 [5%] vs 4 [6.1%] patients, P = 1). One-year survival (95.56% vs 90.61%, P = .48) and all-cause hospital readmission rate (Gray's test: P = .532) were also comparable. Patients who underwent lateral thoracotomy had significantly less early right ventricular failure (24.4% vs 53.7%, P = .004), although they had more follow-up tricuspid regurgitation (17.6% vs 0%, P = .030) and volume overload readmissions (Gray's test: P = .0005).

CONCLUSIONS

Our data suggest that lateral thoracotomy is a safe although not necessarily superior alternative to median sternotomy for HeartMate 3 implantation in the perioperative and postoperative periods, because it precludes concomitant tricuspid valve repairs and may be associated with increased risk of late tricuspid regurgitation and volume overload readmissions.

The frail patient undergoing cardiac surgery: lessons learned and future perspectives

Frailty is a geriatric condition characterized by the reduction of the individual's homeostatic reserves. It determines an increased vulnerability to endogenous and exogenous stressors and can lead to poor outcomes. It is an emerging concept in perioperative medicine, since an increasing number of patients undergoing surgical interventions are older and the traditional models of care seem to be inadequate to satisfy these patients' emerging clinical needs. Nowadays, the progressive technical and clinical improvements allow to offer cardiac operations to an older, sicker and frail population. For these reasons, a multidisciplinary team involving cardiac surgeons, clinical cardiologists, anesthesiologists, and geriatricians, is often needed to assess, select and provide tailored care to these high-risk frail patients to optimize clinical outcomes. There is unanimous agreement that frailty assessment may capture the individual's biological decline and the heterogeneity in risk profile for poor health-related outcomes among people of the same age. However, since commonly used preoperative scores for cardiac surgery fail to capture frailty, a specific preoperative assessment with dedicated tools is warranted to correctly recognize, measure and quantify frailty in these patients. On the contrary, pre-operative and post-operative interventions can reduce the risk of complications and support patient recovery promoting surgical resilience. Minimally invasive cardiac procedures aim to reduce surgical trauma and may be associated with better clinical outcome in this specific sub-group of high-risk patients. Among postoperative adverse events, the occurrence of delirium represents a risk factor for several unfavorable outcomes including mortality and subsequent cognitive decline. Its presence should be carefully recognized, triggering an adequate, evidence based, treatment. There is evidence, from several cross-section and longitudinal studies, that frailty and delirium may frequently overlap, with frailty serving both as a predisposing factor and as an outcome of delirium and delirium being a marker of a latent condition of frailty. In conclusion, frail patients are at increased risk to experience poor outcome after cardiac surgery. A multidisciplinary approach aimed to recognize more vulnerable individuals, optimize pre-operative conditions, reduce surgical invasivity and improve post-operative recovery is required to obtain optimal long-term outcome.

Does lateral approach preserve the right ventricular function after HeartMate 3 insertion?

OBJECTIVES

Lateral thoracotomy (LT) approach may preserve the right ventricular (RV) function after left ventricular assist device (LVAD) implantation. This study evaluated the short- and long-term RV function using echocardiography after LVAD implantation via LT or median sternotomy (sternotomy).

METHODS

The patients who underwent HeartMate 3 implantation were retrospectively reviewed. The RV function was assessed before and 1 month and 1 year after LVAD implantation. The primary and secondary outcomes were all-cause mortality and a composite of death or readmission due to RV failure, respectively.

RESULTS

Of the 195 patients, 55 (28%) underwent LT and 140 (72%) underwent sternotomy. There were no significant differences in the preoperative RV geometry or function. One month after the LVAD implantation, the LT group had a smaller RV end-diastolic dimension [42 (29-48) vs 47 (42-52) mm; P = 0.003] and RV end-diastolic area [25 (21-28) vs 29 (24-36) cm2; P < 0.001] and a greater RV fractional area change [30 (25-34)% vs 28 (23-31)%; P = 0.04] and peak systolic tissue velocity [8 (7-9) vs 7 (6-8) cm/s; P = 0.01]. Twenty-four patients died and 46 met the composite end point. Kaplan-Meier curve analysis did not reveal significant differences between LT and sternotomy in the 2-year survival (93% vs 83%; log-rank test, P = 0.28) and adverse event rate (76% vs 71%; log-rank test, P = 0.65).

CONCLUSIONS

LT approach yielded a better-preserved RV function at 1 month; however, there were no significant differences in the 2-year survival and adverse event rates.

Durable Mechanical Circulatory Support: JACC Scientific Statement

Despite advances in medical therapy for patients with stage C heart failure (HF), survival for patients with advanced HF is <20% at 5 years. Durable left ventricular assist device (dLVAD) support is an important treatment option for patients with advanced HF. Innovations in dLVAD technology have reduced the risk of several adverse events, including pump thrombosis, stroke, and bleeding. Average patient survival is now similar to that of heart transplantation at 2 years, with 5-year dLVAD survival now approaching 60%. Unfortunately, greater adoption of dLVAD therapy has not been realized due to delayed referral of patients to advanced HF centers, insufficient clinician knowledge of contemporary dLVAD outcomes (including gains in quality of life), and deprioritization of patients with dLVAD support waiting for heart transplantation. Despite these challenges, novel devices are on the horizon of clinical investigation, offering smaller size, permitting less invasive surgical implantation, and eliminating the percutaneous lead for power supply.

Novel Plug Device for HeartMate 3 Explantation: First Multicenter Experience

Patients undergoing explantation of left ventricular assist devices (LVADs) after improvement of myocardial function remain a minority. Nevertheless, considering the growing population of LVAD patients, increasing demand for new explantation strategies is expected. Herein, we present a retrospective review of seven patients undergoing HeartMate3 explantation with the use of a custom-made apical ring plug in four medical centers. The primary outcome was status at intensive care unit discharge. Secondary outcomes included perioperative complications and transfusions. Six out of seven patients were males. The median age at explantation and time on LVAD support was 35 years (range:13-73) and 10 months (range:9-24), respectively. No technical difficulties were experienced during plug implantation via a conventional sternotomy or through a left lateral thoracotomy, either with or without cardiopulmonary bypass. Perioperative transfusions ranged from 0 to 3 units/patient. No re-operations for bleeding, hemorrhagic, embolic, or plug-related infective events were observed. Heparin was started 6 hours after surgery as a bridge to oral anticoagulation (international normalized ratio: 2-2.5). All patients were discharged alive from intensive care unit. This novel plug device for HeartMate3 explantation was successfully and safely implanted in this first patient series. Notwithstanding, its use should still be considered off-label and larger studies are required to investigate its long-term results.

Is There a Sex Gap in Outcomes of Comparable Patients Supported with Left Ventricular Assist Devices?

OBJECTIVES

Historically, females were described as suffering from worse outcomes after left ventricular assist device (LVAD) implantation. However, females' preoperative conditions are unique, making direct comparisons with males challenging. This study aimed to select through propensity score (PS) matching two preoperatively comparable populations of females and males and test if any real sex-related difference exists regarding survival and adverse events after LVAD implantation.

METHODS

This retrospective single-center observational study investigated patients who received LVAD implantation between 2010 and 2018. PS matching was applied to balance preoperative heterogeneity between males and females. Primary endpoint was survival at follow-up. Secondary endpoints included perioperative outcomes and LVAD-related adverse events.

RESULTS

92 fully comparable females(n=46) and males(n=46) were selected after PS matching (median age:57 years, min-max:18-75). 26.1% of patients required preoperative mechanical circulatory support. Females needed more intraoperative fresh frozen plasma (p<0.001) and platelets transfusions (p=0.008) compared to males, but postoperative outcomes were comparable between groups. In-hospital, 1-year and 2-year survival were 78.3%, 69.6% and 65.2%, respectively, with no differences between groups. Survival probability remained comparable up to 8 years of follow-up(p=0.35). Overall, females showed a higher rate of strokes(p=0.039) compared to males in the follow-up time.

CONCLUSIONS

After reducing preoperative heterogeneity between females and males, survival after LVAD implantation does not differ based on sex. However, differences might exist in terms of higher transfusions and strokes in females. Reducing preoperative sex disparities and developing intraoperative and anticoagulation strategies which acknowledge sex-related variations might help abolishing differences in LVAD outcomes.

Biocompatibility of an apical ring plug for left ventricular assist device explantation: Results of a feasibility pre-clinical study

BACKGROUND

Patients receiving left ventricle assist devices (LVADs) as bridge to recovery remain a minority with 1%-5% of LVADs explanted after improvement of myocardial function. Nevertheless, considering the growing population of patients supported with LVADs, an increasing demand of new explantation strategies is expected in the near future. A novel plug for LVAD explantation has been developed and its biocompatibility profile needs to be proved. This study tested the biocompatibility of this novel plug in an in vivo ovine model.

METHODS

Six adult Blackhead Persian female sheep received plug implantation on the cardiac apex via minimally invasive approach and were clinically observed up to 90 days. Echocardiography was performed to detect thrombus formation or further plug-related complications. After the observation period, euthanasia was performed and samples including the plug and the surrounding tissues were obtained to be analyzed with correlative light and electron microscopy. Organ necrosis, ischemia and peripheral embolism were investigated.

RESULTS

Three animals survived surgery and completed the follow-up time without experiencing clinical complications. Echocardiographic controls excluded the presence of an intracavitary thrombus in the left ventricle (LV). Autopsy confirmed no signs of local infection, LV thrombus or peripheral embolism. Light and electron microscopy revealed an intact epithelium covering a layer of connective tissue on the plug surface facing the heart lumen.

CONCLUSIONS

This novel apical plug for LVAD explantation allows for endothelial and connective tissue growth on its ventricular side within 90 days from surgery. Further studies are required to fully demonstrate the biocompatibility of this apical plug and investigate the optimal anticoagulation regimen to be applied after implantation.

Sex differences in outcomes following less-invasive left ventricular assist device implantation

Background

Worse outcomes in women compared to men undergoing left ventricular assist device (LVAD) implantation remain an underestimated problem in heart failure (HF) patients. With device miniaturization, less-invasive LVAD implantation techniques have gained relevance, but their impact on outcomes in women is unknown. This study investigates sex-related differences in patients undergoing LVAD implantation through less-invasive procedures.

Methods

This retrospective single-center cohort study included patients who underwent isolated LVAD implantation between 2011 and 2018 through less-invasive techniques. Propensity score matching (PSM) was utilized to balance preoperative heterogeneity. Primary endpoint was two-year survival, and secondary endpoints included long-term survival, surgical outcomes and postoperative adverse events.

Results

Baseline analysis of 191 patients (females 18.3%) showed differences in terms of age [female (median, 52; IQR, 47-61); male (median, 58.5; IQR, 49-66); P=0.005], underlying diagnosis (P<0.001), INTERMACS profile (P=0.009), history of previous cardiac surgery (P=0.049) and preoperative creatinine values [female (median, 110; IQR, 71-146); male (median, 126; IQR, 9-168); P=0.049]. Over a follow-up of 460.68 patient-years, Kaplan-Meyer analysis showed better survival in females (P=0.027) and a similar probability of cardiac transplantation (P=0.288). After PSM, females showed higher needs for intraoperative fresh frozen plasma (P=0.044) and platelets (P=0.001) but comparable postoperative outcomes. No sex-related differences were noticed regarding two-year outcomes, long-term survival and adverse events. LVAD-related infections remained the most common complication with males experiencing more pump infections than women (P=0.050).

Conclusions

Patients receiving less-invasive LVAD implantation do not show significant sex-related differences in short and long-term outcomes and survival. Prospective studies are needed to evaluate the role of less-invasive techniques in reducing sex-based disparities after LVAD implantation.

Extracorporeal membrane oxygenation in patients with severe respiratory failure from COVID-19

PURPOSE

Limited data are available on venovenous extracorporeal membrane oxygenation (ECMO) in patients with severe hypoxemic respiratory failure from coronavirus disease 2019 (COVID-19).

METHODS

We examined the clinical features and outcomes of 190 patients treated with ECMO within 14 days of ICU admission, using data from a multicenter cohort study of 5122 critically ill adults with COVID-19 admitted to 68 hospitals across the United States. To estimate the effect of ECMO on mortality, we emulated a target trial of ECMO receipt versus no ECMO receipt within 7 days of ICU admission among mechanically ventilated patients with severe hypoxemia (PaO₂/FiO₂ < 100). Patients were followed until hospital discharge, death, or a minimum of 60 days. We adjusted for confounding using a multivariable Cox model.

RESULTS

Among the 190 patients treated with ECMO, the median age was 49 years (IQR 41-58), 137 (72.1%) were men, and the median PaO₂/FiO₂ prior to ECMO initiation was 72 (IQR 61-90). At 60 days, 63 patients (33.2%) had died, 94 (49.5%) were discharged, and 33 (17.4%) remained hospitalized. Among the 1297 patients eligible for the target trial emulation, 45 of the 130 (34.6%) who received ECMO died, and 553 of the 1167 (47.4%) who did not receive ECMO died. In the primary analysis, patients who received ECMO had lower mortality than those who did not (HR 0.55; 95% CI 0.41-0.74). Results were similar in a secondary analysis limited to patients with PaO₂/FiO₂ < 80 (HR 0.55; 95% CI 0.40-0.77).

CONCLUSION

In select patients with severe respiratory failure from COVID-19, ECMO may reduce mortality.