Impact of Residual Valve Disease on Survival After Implantation of Left Ventricular Assist Devices

Concurrent valvular procedures during left ventricular assist device implantation and outcomes: A comprehensive analysis of the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3 trial portfolio

BACKGROUND

Correction of valvular disease is often undertaken during left ventricular assist device (LVAD) implantation with uncertain benefit. We analyzed clinical outcomes with HeartMate 3 (HM3; Abbott) LVAD implantation in those with various concurrent valve procedures (HM3+VP) with those with an isolated LVAD implant (HM3 alone).

METHODS

The study included 2200 patients with HM3 implanted within the Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy with HeartMate 3 (MOMENTUM 3) trial portfolio who underwent 820 concurrent procedures among which 466 (21.8%) were HM3+VP. VPs included 101 aortic, 61 mitral, 163 tricuspid; 85 patients had multiple VPs. Perioperative complications, major adverse events, and survival were analyzed.

RESULTS

Patients who underwent HM3+VP had higher-acuity Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profiles (1-2: 41% vs 31%) compared with no VPs (P < .05). The cardiopulmonary bypass time (124 vs 76 minutes; P < .0001) and hospital length of stay (20 vs 18 days; P < .0001) were longer in HM3+VP. A higher incidence of stroke (4.9% vs 2.4%), bleeding (33.9% vs 23.8%), and right heart failure (41.5% vs 29.6%) was noted in HM3+VP at 0 to 30 days (P < .01), with no difference in 30-day mortality (3.9% vs 3.3%) or 2-year survival (81.7% vs 80.8%). Analysis of individual VP showed no differences in survival compared to HM3 alone. No differences were noted among patients with either significant mitral (moderate or worse) or tricuspid (moderate or worse) regurgitation with or without corrective surgery.

CONCLUSIONS

Concurrent VPs, commonly performed during LVAD implantation, are associated with increased morbidity during the index hospitalization, with no effect on short- and long-term survival. There is sufficient equipoise to consider a randomized trial on the benefit of commonly performed VPs (such as mitral or tricuspid regurgitation correction), during LVAD implantation.

Transcatheter valvular therapies in patients with left ventricular assist devices

Aortic, mitral and tricuspid valve regurgitation are commonly encountered in patients with continuous-flow left ventricular assist devices (CF-LVADs). These valvular heart conditions either develop prior to CF-LVAD implantation or are induced by the pump itself. They can all have significant detrimental effects on patients' survival and quality of life. With the improved durability of CF-LVADs and the overall rise in their volume of implants, an increasing number of patients will likely require a valvular heart intervention at some point during CF-LVAD therapy. However, these patients are often considered poor reoperative candidates. In this context, percutaneous approaches have emerged as an attractive "off-label" option for this patient population. Recent data show promising results, with high device success rates and rapid symptomatic improvements. However, the occurrence of distinct complications such as device migration, valve thrombosis or hemolysis remain of concern. In this review, we will present the pathophysiology of valvular heart disease in the setting of CF-LVAD support to help us understand the underlying rationale of these potential complications. We will then outline the current recommendations for the management of valvular heart disease in patients with CF-LVAD and discuss their limitations. Lastly, we will summarize the evidence related to transcatheter heart valve interventions in this patient population.

Concomitant cardiac surgery procedures during left ventricular assist device implantation: single-centre experience

Background

Additional cardiac pathologies including tricuspid or mitral valve regurgitation are common in left ventricular assist device (LVAD) recipients and whether to address them remains controversial. We present our institutional outcomes of concomitant cardiac procedures, other than temporary right ventricular (RV) support, at the time of LVAD implantation.

Methods

From 03/2006 to 06/2020, 352 adult patients {median age 60 [interquartile range (IQR): 52-66] years; INTERMACS level 1 29%; INTERMACS level 2 17%; INTERMACS level 3 23%, INTERMACS level 4-6 31%; male 86%} underwent continuous-flow LVAD [Medtronic HVAD^® (HVAD) 50%; Abbott HeartMate II^TM (HMII) 17%; Abbott HeartMate 3^TM (HM3) 33%] implantation. Concomitant valvular procedures were performed in 86 patients (24%) and the majority of patients received the LVAD as bridge to candidacy (BTC) for transplant (74%). Primary study endpoints were short- and mid-term mortality, as well as need for temporary RV support.

Results

Tricuspid valve annuloplasty was the most frequent concomitant procedure (77%), followed by aortic valve replacements (AVRs) or Park's stitch (33%). Temporary RV support was common in the study cohort (35%) using either extracorporeal life support (ECLS, 37%) or a temporary RV assist device (RVAD, 63%). A less invasive (LIS) implantation technique was pursued in 12%. Thirty-day mortality was comparable between those with and without concomitant surgery (4% vs. 6%, P=0.426). In-hospital mortality was significantly higher for additional interventions (22% vs. 14%, P=0.05), whereas one-year survival was similar (71% vs. 79%, P=0.106).

Conclusions

Concomitant cardiac procedures, especially tricuspid and aortic valve surgery, are frequent but are associated with a higher perioperative morbidity and mortality.

Impact of Pre-Existing Mitral Regurgitation Following Left Ventricular Assist Device Implant

OBJECTIVES

Optimal management of significant mitral regurgitation (SMR) during left ventricular assist device (LVAD) placement remains uncertain. This study evaluates the effect of untreated preop SMR on outcomes following LVAD implant.

METHODS

Adults undergoing primary LVAD placement from April 2004 to May 2017 were included. Most recent preop transthoracic echocardiogram (TTE) was used to divide patients into an SMR group with moderate or greater regurgitation, and a group without SMR. Patients underwent LVAD implant without correction of SMR. Primary endpoint was 3-year postoperative survival, with secondary endpoints of length of stay (LOS), resolution of SMR following LVAD on postdischarge (30 day) TTE, and 1-year TTE.

RESULTS

LVAD placement was performed in 270 patients, 172 (63.7%) without SMR and 98 (36.3%) with SMR. There were no differences in comorbidities including diabetes, hypertension, and renal disease. Preop ejection fraction was similar, but a higher pulmonary vascular resistance was recorded in the SMR group (3.6 vs 3.0 Wood Units, P = 0.048). There was no difference in 3-year mortality between the 2 cohorts (log-rank P = 0.0.803). The SMR group had decreased LOS (median 19.5 vs 22 days, P = 0.009). Of the 98 SMR patients, 91 (92.9%) had resolution of SMR to less than moderate at 30 days. At 1 year, 15% of those with preoperative SMR had recurrent SMR.

CONCLUSIONS

Patients undergoing LVAD placement with preop SMR experience no differences in mortality, and a majority experience resolution of MR after implant. Longer-term SMR recurrence and need for mitral intervention with LVAD implant warrant further investigation.

Understanding Longitudinal Changes in Pulmonary Vascular Resistance After Left Ventricular Assist Device Implantation

BACKGROUND

Elevated pulmonary vascular resistance (PVR) is common in patients with advanced heart failure. PVR generally improves after left ventricular assist device (LVAD) implantation, but the rate of decrease has not been quantified and the patient characteristics most strongly associated with this improvement are unknown.

METHODS AND RESULTS

We analyzed 1581 patients from the Interagency Registry for Mechanically Assisted Circulatory Support registry who received a primary continuous-flow LVAD, had a baseline PVR of ≥3 Wood units (WU), and had PVR measured at least once postoperatively. Multivariable linear mixed effects modeling was used to evaluate independent associations between postoperative PVR and patient characteristics. PVR decreased by 1.53 WU (95% confidence interval [CI] 1.27-1.79 WU) per month in the first 3 months postoperatively, and by 0.066 WU (95% CI 0.060-0.070 WU) per month thereafter. Severe mitral regurgitation at any time during follow-up was associated with a 1.29 WU (95% CI 1.05-1.52 WU) higher PVR relative to absence of mitral regurgitation at that time. In a cross-sectional analysis, 15%-25% of patients had persistently elevated PVR of ≥3 WU at any given time within 36 months after LVAD implantation.

CONCLUSION

The PVR tends to decrease rapidly early after implantation, and only more gradually thereafter. Residual mitral regurgitation may be an important contributor to elevated postoperative PVR. Future research is needed to understand the implications of elevated PVR after LVAD implantation and the optimal strategies for prevention and treatment.

MitraClip implantation followed by insertion of a left ventricular assist device in patients with advanced heart failure

Aims

Mitral valve regurgitation (MR) is common in patients with advanced heart failure (HF). Percutaneous mitral valve repair (PMVR) via MitraClip (MC) has emerged as a feasible treatment strategy for these high‐risk patients. However, as HF often further progresses, there is a frequent need for left ventricular assist device (LVAD) implantation in these patients. We aimed to investigate whether prior MC implantation affects the subsequent LVAD implantation and outcome.

Methods and results

Thirty‐seven patients with advanced HF and significant MR who underwent LVAD implantation were retrospectively analysed. Follow‐up data were collected at 1 year after LVAD implantation. Primary endpoint was all‐cause mortality. Secondary endpoint included peri‐operative parameters and clinical development depicted as New York Heart Association (NYHA) class and Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) level. Seventeen patients initially received a MC device (MC group), resulting in a significant reduction in MR grade. After MC, NYHA class and INTERMACS level further worsened, leading to subsequent LVAD implantation after a median time of 475 days in the MC group. At LVAD implantation, overall characteristics were comparable with those of the patients undergoing LVAD implantation without prior MC placement (no‐MC group). Procedural data revealed a higher incidence of right ventricular (RV) failure needing mechanical RV assistance and a longer need for nitric oxide ventilation in the MC group after LVAD implantation. One‐year survival was slightly better in the no‐MC group compared with the MC group [41% (n = 7/17) vs. 65% (n = 13/20); P = 0.15], albeit event‐free survival was comparable between both groups, MC and no‐MC.

Conclusions

LVAD implantation after MC is feasible and safe. However, in patients with advanced HF and severe MR, PMVR may only delay a needed LVAD implantation and thereby lead to poorer peri‐operative RV function and impaired outcome. Arguably, these patients might benefit from the timely management of advanced HF by the means of early LVAD implantation or heart transplantation.

In-Hospital Outcomes of Left Ventricular Assist Device Implantation and Concomitant Valvular Surgery

Valvular heart disease is common among left ventricular assist device (LVAD) recipients. However, its management at the time of LVAD implantation remains controversial. Patients who underwent LVAD implantation and concomitant aortic (AVR), mitral (MVR), or tricuspid valve (TVR) repair or replacement from 2010 to 2017 were identified using the national inpatient sample. End points were in-hospital outcomes, length of stay, and cost. Procedure-related complications were identified via ICD-9 and ICD-10 coding and analysis was performed via mixed effect models. A total of 25,171 weighted adults underwent LVAD implantation without valvular surgery, 1,329 had isolated TVR, 1,021 AVR, 377 MVR, and 615 had combined valvular surgery (411 had TVR + AVR, 115 TVR + MVR, 62 AVR + MVR, 25 AVR + MVR + TVR). During the study period, rates of AVR decreased and combined valvular surgeries increased. Patients who underwent TVR or combined valvular surgery had overall higher burden of co-morbidities than LVAD recipients with or without other valvular procedures. Postoperative bleeding was higher with AVR whereas acute kidney injury requiring dialysis was higher with TVR or combined valvular surgery. In-hospital mortality was higher with AVR, MVR, or combined surgery without differences in the rates of stroke. Length of stay did not differ significantly among groups but cost of hospitalization and nonroutine discharge rates were higher for cases of TVR and combined surgery. Approximately 1 in 9 LVAD recipients underwent concomitant valvular surgery and TVR was the most frequently performed procedure. In-hospital mortality and cost were lower among those who did not undergo valvular surgery.

Atrial arrhythmias in patients with left ventricular assist devices

PURPOSE OF REVIEW

Atrial arrhythmias commonly occur in patients with advanced heart failure with reduced ejection fraction (HFrEF) who require left ventricular assist devices (LVADs) implantation. This review summarizes the current literature regarding the incidence, prevalence, and predictors of atrial arrhythmias in LVAD patients and its impact on the clinical outcomes. Moreover, we review the mechanisms and management strategies of atrial arrhythmias in this population.

RECENT FINDINGS

Atrial arrhythmias including atrial fibrillation, atrial flutter, and atrial tachycardia are highly prevalent in patients with advanced HFrEF before or after the LVAD implantation. Atrial arrhythmias have a significant impact on overall clinical outcome including survival, heart failure hospitalization, quality of life, thromboembolic events and resource utilization. Atrial fibrillation and other atrial arrhythmias frequently coexist in this population. In patients with atrial arrhythmias and LVAD, anticoagulation and cardiovascular implantable electronic devices should be closely monitored and managed to prevent thromboembolic events or inappropriate shocks. Rhythm and rate control strategies are comparable regarding overall clinical outcomes in this population. LVADs induce favorable atrial remodeling in patients with HFrEF.

SUMMARY

Atrial arrhythmias are highly common in LVAD patients and have significant impact on overall clinical outcomes. Further studies are needed to determine optimal management and prevention of atrial arrhythmias in LVAD population.