An examination of survival by sex and race in the HeartWare Ventricular Assist Device for the Treatment of Advanced Heart Failure (ADVANCE) Bridge to Transplant (BTT) and continued access protocol trials

LVAD therapy as a catalyst to heart failure remission and myocardial recovery

The management of chronic heart failure over the past decade has witnessed tremendous strides in medical optimization and device therapy including the use of left ventricular assist devices (LVAD). What we once thought of as irreversible damage to the myocardium is now demonstrating signs of reverse remodeling and recovery. Myocardial recovery on the structural, molecular, and hemodynamic level is necessary for sufficient recovery to withstand explant and achieve sustained recovery post-LVAD. Guideline-directed medical therapy and unloading have been shown to aid in recovery with the potential to successfully explant the LVAD. This review will summarize medical optimization, assessment for recovery, explant methodologies and outcomes post-recovery with explant of durable LVAD.

Sex disparities in left ventricular assist device implantation outcomes: A systematic review and meta-analysis of over 50 000 patients

BACKGROUND

Left ventricular assist devices (LVAD) represent an important therapeutic option for patients progressing to end-stage heart failure. Women have been historically underrepresented in LVAD studies, and have been reported to have worse outcomes despite technological optimisation. We aimed to systematically explore the evidence on sex disparities in the use and outcomes of LVAD implantation.

METHODS

A systematic database search with meta-analysis was conducted of comparative original articles of men versus women undergoing LVAD implantation, in EMBASE, MEDLINE, Cochrane database and Google Scholar, from inception to July 2022. Primary outcomes were stroke (haemorrhagic and ischaemic) and early/overall mortality. Secondary outcomes were LVAD thrombosis, right VAD implantation, major bleeding, kidney dysfunction, and device/driveline infection.

RESULTS

Our search yielded 137 relevant studies, including 22 meeting the inclusion criteria with a total of 53 227 patients (24.2% women). Overall mortality was higher in women (odds ratio [OR] 1.35, 95% confidence interval [CI] 1.05-1.62, p = 0.02), as was overall stroke (OR 1.32, 95%CI 1.06-1.66, p = 0.01), including ischemic (OR 1.80, 95%CI 1.22-2.64, p = 0.003) and haemorrhagic (OR 1.72, 95%CI 1.09-2.70, p = 0.02). Women had more frequent right VAD implantation (OR 2.11, 95%CI 1.24-3.57, p = 0.006) and major bleeding (OR 1.40, 95%CI 1.06-1.85, p = 0.02). Kidney dysfunction, LVAD thrombosis, and device/driveline infections were comparable between sexes.

CONCLUSIONS

Our analysis suggests that women face a greater risk of adverse events and mortality post-LVAD implantation. Although the mechanisms remain unclear, the difference in outcomes is thought to be multifactorial. Further research, that includes comprehensive pre-operative characteristics and post-operative outcomes, is encouraged.

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.

Propensity Score-Matched Comparison of Right Ventricular Strain in Women and Men Before and After Left Ventricular Assist Device Implantation

Objective: Adverse events following left ventricular assist device (LVAD) implantation are more common in women than in men, but the impact of gender differences on right ventricular (RV) failure is not well defined. Therefore, we calculated RV strain before and after LVAD implantation in matched groups of men and women to determine if gender differences in RV failure after LVAD might account for the gender differences in overall outcomes. Methods: RV free wall longitudinal strain (FWS) and fractional area change were calculated preoperatively and 3 months postoperatively using speckle-tracking echocardiography analysis. A total of 172 patients (86 women, 86 men) were then propensity score matched (1:1) for comparison. Results: Although women had higher preoperative CHA₂DS₂-VASc scores and more frequent moderate mitral regurgitation than men (P = 0.018), the preoperative hemodynamic parameters were similar. Preoperative RV-FWS was -6.7% in women and -6.0% in men (P = 0.65). Postoperatively, women had more progression to severe tricuspid regurgitation (TR) than men (15% vs 7%, P = 0.06). At 3 months the RV-FWS was -7.7% in women and -7.0% in men (P = 0.59). Postoperative TR was moderate-severe in 20% of women and in 9% of men (P = 0.001). Women had a higher incidence of venous thromboembolism, cardiac arrhythmias, and bleeding compared with men. Women also had higher mortality rates at discharge and 30 days after surgery, but the survival rates at 5 years were similar. Conclusions: RV strain measurements track standard hemodynamic and echocardiographic parameters and confirm that gender differences in outcomes following LVAD implantation are not related to gender differences in RV failure rates.

Long-term survival on LVAD support: Device complications and end-organ dysfunction limit long-term success

BACKGROUND

Preoperative variables can predict short term left ventricular assist device (LVAD) survival, but predictors of extended survival remain insufficiently characterized.

METHOD

Patients undergoing LVAD implant (2012-2018) in the Intermacs registry were grouped according to time on support: short-term (<1 year, n = 7,483), mid-term (MT, 1-3 years, n = 5,976) and long-term (LT, ≥3 years, n = 3,015). Landmarked hazard analyses (adjusted hazard ratio, HR) were performed to identify correlates of survival after 1 and 3 years of support.

RESULTS

After surviving 1 year of support, additional LVAD survival was less likely in older (HR 1.15 per decade), Caucasian (HR 1.22) and unmarried (HR 1.16) patients (p < 0.05). After 3 years of support, only 3 preoperative characteristics (age, race, and history of bypass surgery, p < 0.05) correlated with extended survival. Postoperative events most negatively influenced achieving LT survival. In those alive at 1 year or 3 years, the occurrence of postoperative renal (creatinine HR MT = 1.09; LT HR = 1.10 per mg/dl) and hepatic dysfunction (AST HR MT = 1.29; LT HR = 1.34 per 100 IU), stroke (MT HR = 1.24; LT HR = 1.42), infection (MT HR = 1.13; LT HR = 1.10), and/or device malfunction (MT HR = 1.22; LT HR = 1.46) reduced extended survival (all p ≤ 0.03).

CONCLUSIONS

Success with LVAD therapy hinges on achieving long term survival in more recipients. After 1 year, extended survival is heavily constrained by the occurrence of adverse events and postoperative end-organ dysfunction. The growth of destination therapy intent mandates that future LVAD studies be designed with follow up sufficient for capturing outcomes beyond 24 months.

Does Size Matter for Female Continuous-flow LVAD Recipients? A Translational Approach to a Decade Long Question

Females have increased risk of right-ventricular failure (RVF) and 3 month mortality after left-ventricular assist device (LVAD) implantation. In this translational study, we tested the hypothesis that sex differences in outcomes are driven by pump-induced LV size-volume mismatch, due to a negative impact on interventricular septal (IVS) interdependence. Adult continuous-flow LVAD recipients from the International Society For Heart And Lung Transplantation Mechanically Assisted Circulatory Support registry (n = 15,498) were studied to determine association of female sex with outcomes of 3 month mortality and RVF. Female sex was associated with smaller preimplant left-ventricular end-diastolic diameter (6.5 vs. 6.9 cm, p < 0.001), increased 3 month mortality (odds ratio [OR]: 1.42, p < 0.001) and RVF (OR: 1.18, p = 0.005). Smaller left-ventricular end-diastolic diameter was associated with worse outcomes after LVAD implantation (OR for mortality: 1.20, p < 0.001; RVF: 1.09, p < 0.001), and attenuated the association of female sex with these outcomes. In test bench heart phantoms (n = 4), the IVSs of smaller hearts demonstrated abnormal leftward shift earlier than larger hearts (volume change at IVS shift: 40 [95% confidence interval: 30-52] vs. 50 [95% confidence interval: 48-69] ml). Smaller LV size partially mediates worse post-LVAD outcomes for female patients, due to lower volume thresholds for adverse IVS shifting.

Impact of Race on Clinical Outcomes After Implantation With a Fully Magnetically Levitated Left Ventricular Assist Device: An Analysis From the MOMENTUM 3 Trial

BACKGROUND

Heart failure disproportionately affects Black patients. Whether differences among race influence outcomes in advanced heart failure with use of a fully magnetically levitated continuous-flow left ventricular assist device remains uncertain.

METHODS

We included 515 IDE (Investigational Device Exemption) clinical trial patients and 500 Continued Access Protocol patients implanted with the HeartMate 3 left ventricular assist device in the MOMENTUM 3 study (Multicenter Study of MagLev Technology in Patients Undergoing Mechanical Circulatory Support Therapy With HeartMate 3). Outcomes were compared between Black and White left ventricular assist device recipients for the primary end point of survival free of disabling stroke or reoperation to replace or remove a malfunctioning device at 2 years, overall survival, adverse events, 6-minute walk distance, and quality of life scores.

RESULTS

Of 1015 HeartMate 3 patients, 675 were self-identified as White and 285 as Black individuals. The Black patient cohort was younger, more obese and with a history of hypertension, and more nonischemic cause of heart failure, relative to the White patient group. Black and White patients did not experience a difference in the primary end point (81.1% versus 77.9%; hazard ratio, 1.08 [95% CI, 0.76-1.54], P=0.6568). Black patients were at higher risk of adverse events (calculated as events per 100 patient-years), including bleeding (75.4 versus 63.5; P<0.0001), stroke (9.5 versus 7.2; P=0.0183), and hypertension (10.1 versus 3.2; P<0.0001). The 6-minute walk distance was not different at baseline and 6 months between the groups, however, the absolute change from baseline was greater for White patients (median: +183.0 [interquartile range, 42.0-335.3] versus +163.8 [interquartile range, 42.3-315.0] meters, P=0.01). The absolute quality of life measurement (EuroQoL group, 5-dimension, 5-level instrument visual analog scale) at baseline and 6 months was better in the Black patient group, but relative improvement from baseline to 6 months was greater in White patients (median: +20.0 [interquartile range, 5.0-40.0] versus +25.0 [interquartile range, 10.0-45.0]; P=0.0298).

CONCLUSIONS

Although the survival free of disabling stroke or reoperation to replace/remove a malfunctioning device at 2 years with the HM 3 left ventricular assist device did not differ by race, Black HeartMate 3 patients experienced a higher morbidity burden and smaller gains in functional capacity and quality of life when compared with White patients. These findings require efforts designed to better understand and overcome these gaps through systematic identification and tackling of putative factors. Registration: URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02224755 and NCT02892955.

Gender differences in psychosocial and clinical characteristics in the European Registry for Patients with Mechanical Circulatory Support

BACKGROUND

Not much is known about psychosocial characteristics of men and women receiving continuous flow left ventricular assist devices (CF LVAD).

OBJECTIVE

To investigate gender differences in clinical and psychosocial (demographic, behavioral, psychological) characteristics in CF LVAD recipients.

METHODS

We analyzed European Registry for Patients with Mechanical Circulatory Support (EUROMACS) data (N=2395, 16.8% women; 2011 to 2017) and compared pre-implant characteristics in men and women intended for bridge-to-transplant (BTT) or destination therapy (DT).

RESULTS

Women were underrepresented [DT (n=61): 13.4%; BTT (n=341): 17.6%]. They were more likely to be divorced/separated, widowed, in unstable clinical condition, and non-working (DT only), but less likely to be smokers, to have ischemic cardiomyopathy or diabetes, and younger (BTT only) than men. Missing data were abundant, especially those that reflect psychological characteristics (>87%).

CONCLUSION

Gender differences were noted, some specific to device strategy. Improved collection of psychosocial characteristics is warranted to elucidate their relationship to future prognosis.

Gender Differences in Mortality After Left Ventricular Assist Device Implant: A Causal Mediation Analysis Approach

We used the International Society for Heart and Lung Transplantation (ISHLT) Registry for Mechanically Assisted Circulatory Support (IMACS) database to examine 1) gender differences in post-left ventricular assist device (LVAD) mortality in the contemporary era and 2) preimplant clinical factors that might mediate any observed differences. Adults who received continuous-flow (CF)-LVAD from January 2013 to September 2017 (n = 9,565, age: 56.2 ± 13.2 years, 21.6% female, 31.1% centrifugal pumps) were analyzed. An inverse probability weighted Cox proportional hazards model was used to estimate association of female gender with all-cause mortality, adjusting for known covariates. Causal mediation analysis was performed to test plausible preimplant mediators mechanistically underlying any association between female gender and mortality. Females had higher mortality after LVAD (adjusted hazard ratio [HR]: 1.36; p < 0.0001), with significant gender × time interaction (p = 0.02). An early period of increased risk was identified, with females experiencing a higher risk of mortality during the first 4 months after implant (adjusted HR: 1.74; p < 0.0001), but not after (adjusted HR: 1.18; p = 0.16). More severe tricuspid regurgitation and smaller left ventricular end-diastolic diameter at baseline mediated ≈21.9% of the increased early hazard of death in females; however, most of the underlying mechanisms remain unexplained. Therefore, females have increased mortality only in the first 4 months after LVAD implantation, partially driven by worsening right ventricular dysfunction and LV-LVAD size mismatch.

STS INTERMACS Database: The Key to Conduct Single-arm Trials in Advanced Heart Failure Patients

BACKGROUND

Safe introduction of novel mechanical circulatory support (MCS) devices into clinical practice is a challenging process. Single-arm trials using a control arm from existing database is an effective alternative that could be applied for regulatory approval. This study analyzes the capability of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to establish objective performance criteria and select patient population that could be used for future single-arm MCS trials.

METHODS

Patients with INTERMACS profiles IM1-2 and IM3-5, who underwent implant of isolated Left Ventricular Assist Devises between 2014-2017 were included. Both cohorts were further stratified into Shock and Non-Shock groups using surrogate markers of shock (ECMO, temporary VAD, vasopressor infusions). Survival, transplant rates, adverse events, 6 min walk test and quality of life measures were obtained for all 4 groups at 6 and 12 months.

RESULTS

Total of 7,907 patients were divided into IM1-2(n=3,909), IM3-5(n=3,998), Shock(n=3,469) and Non-Shock(n=3,040). Re-categorization occurred in 11% of patients from the IM3-5 group into the Shock group. Overall, patients in the Shock group had similar outcomes to the IM 1-2 group (1-year survival: 86% vs 85%, p=0.74). Patients in the Non-Shock group also had similar outcomes to the IM 3-5 (1-year survival: 90% vs 90%, p=0.43).

CONCLUSIONS

INTERMACS database can successfully establish objective performance criteria and concurrent control group for single-arm trials that could be used to support regulatory approval of new, less invasive MCS. INTERMACS data allows reliable comparisons of outcomes and adverse events.

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.

Essential roles of the dystrophin-glycoprotein complex in different cardiac pathologies

The dystrophin-glycoprotein complex (DGC), situated at the sarcolemma dynamically remodels during cardiac disease. This review examines DGC remodeling as a common denominator in diseases affecting heart function and health. Dystrophin and the DGC serve as broad cytoskeletal integrators that are critical for maintaining stability of muscle membranes. The presence of pathogenic variants in genes encoding proteins of the DGC can cause absence of the protein and/or alterations in other complex members leading to muscular dystrophies. Targeted studies have allowed the individual functions of affected proteins to be defined. The DGC has demonstrated its dynamic function, remodeling under a number of conditions that stress the heart. Beyond genetic causes, pathogenic processes also impinge on the DGC, causing alterations in the abundance of dystrophin and associated proteins during cardiac insult such as ischemia-reperfusion injury, mechanical unloading, and myocarditis. When considering new therapeutic strategies, it is important to assess DGC remodeling as a common factor in various heart diseases. The DGC connects the internal F-actin-based cytoskeleton to laminin-211 of the extracellular space, playing an important role in the transmission of mechanical force to the extracellular matrix. The essential functions of dystrophin and the DGC have been long recognized. DGC based therapeutic approaches have been primarily focused on muscular dystrophies, however it may be a beneficial target in a number of disorders that affect the heart. This review provides an account of what we now know, and discusses how this knowledge can benefit persistent health conditions in the clinic.

Mechanical Circulatory Support in Women

A number of devices can now provide mechanical circulatory support (MCS) to patients with acute cardiogenic shock (CS) and chronic end-stage heart failure (HF). Women differ from men in pathophysiology and natural history of CS and HF, and are usually sicker at admission. Current evidence suggests that women benefit as much as men, if not more, from both temporary and durable MCS for appropriate indications. Yet, women have been under-represented in clinical trials of MCS devices. Limited evidence suggests that women benefit more from temporary MCS in CS associated with acute myocardial infarction. However, in patients with durable left ventricular assist devices (LVADs), women are more likely to experience thromboembolic events and right HF. This review aims to study available evidence and determine areas for further research on gender differences in (a) use of temporary MCS for CS and (b) use of durable LVADs. Use of MCS in conditions specific to, or more common in women (pregnancy, takotsubo cardiomyopathy, peripartum cardiomyopathy, and spontaneous coronary artery dissection) is also discussed.

Sex-Specific Outcomes in Cardiovascular Device Evaluations

Background: Females have historically been underrepresented in cardiovascular device trials. As a result, differences in outcomes for males and females are not possible to be determined in subanalyses. Materials and Methods: Against a backdrop of troubling trends in cardiovascular outcomes for females, we provide a narrative review on the differences in outcomes observed in females undergoing device evaluations in multiple fields of cardiovascular medicine, including coronary revascularization, structural heart disease, and heart failure. We also review predictors of cardiovascular trial nonparticipation as it may provide avenues by which female enrollment in cardiovascular device trials can be improved. Results: Advances have been made in structural heart therapy, where female representation in transcatheter aortic valve replacement studies was nearly 50%. For other indications, coronary revascularization and heart failure, there was clearly a disparity in female recruitment. On average, female representation was 25% in major clinical trials evaluating drug eluting stents, implantable cardioverter defibrillators, cardiac resynchronization defibrillators, and ventricular assist devices. As a result, the best treatment recommendations for females in these fields are currently guided by outcomes evaluated primarily in males. Conclusions: Female enrollment in device clinical trials for coronary revascularization and heart failure has lagged, leaving uncertainty in making benefit/risk assessments of device therapy. The predictors of female nonparticipation in clinical trials can inform a comprehensive strategy to facilitate and enrich the enrollment of females in cardiovascular device trials. This is critical to ensure that sex differences can be considered in treatment selection, so that patients can receive the best available care.

Extracorporeal Membrane Oxygenation as a Bridge to Durable Mechanical Circulatory Support: An Analysis of the STS-INTERMACS Database

BACKGROUND

Limited data are available regarding the outcomes of patients supported by extracorporeal membrane oxygenation (ECMO) who undergo durable mechanical circulatory support implantation (dMCS). We analyzed the clinical characteristics, outcomes, and risk factors for mortality in patients who were bridged with ECMO to dMCS.

METHODS

Adult patients who received dMCS between January 2008 and December 2017 (n=19 824), registered in the Society of Thoracic Surgeons-Interagency Registry for Mechanical Assisted Circulatory Support (STS-INTERMACS) database were included. Baseline characteristics, outcomes, risk factors, and adverse events were compared between ECMO-supported patients (n=933) and INTERMACS profile 1 (IP-1) patients not supported by ECMO (n=2362). A propensity match analysis was performed.

RESULTS

ECMO patients had inferior survival at 12 months (66.1%) than non-ECMO patients (75.4%; P<0.0001). The proportion of patients transplanted at 2 years after dMCS was similar between the ECMO (30.8%) and non-ECMO (31.8%) groups (P=0.49). A multiphase parametric hazard model identified 2 different periods based on risk of death. ECMO patients had a high hazard for death in the first 6 months after implantation (hazard ratio, 2.18 [1.79-2.66]; P<0.001). Multivariable analysis showed that ECMO was an independent risk factor associated with poor outcome during the early phase after dMCS (hazard ratio, 1.69 [1.37-2.09]; P<0.0001) but not during the constant phase. ECMO patients had similar outcomes to non-ECMO patients when a propensity matched cohort was analyzed.

CONCLUSIONS

ECMO-supported patients before dMCS have lower survival compared with other IP-1 patients. A multivariable analysis showed that ECMO is an independent risk factor of poor outcome after dMCS. However, a propensity matched analysis suggested that when important clinical variables are controlled the outcome of both groups is similar. These data support the implantation of dMCS in carefully selected ECMO patients.

Sex Differences in Advanced Heart Failure Therapies

This in-depth review of sex differences in advanced heart failure therapy summarizes the existing literature on implantable cardioverter defibrillators, biventricular pacemakers, mechanical circulatory support, and transplantation with a focus on utilization, efficacy/clinical effectiveness, adverse events, and controversies. One will learn about the controversies regarding efficacy/clinical effectiveness of implantable cardioverter defibrillators and understand why these devices should be implanted in women even if there are sex differences in appropriate shocks. Individuals will learn about the sex differences with biventricular pacemakers with respect to ventricular remodeling and reduction in heart failure hospitalizations/mortality, as well as, possible mechanisms. We will demonstrate sex differences in heart transplantation and waitlist survival. Despite similar survival for women and men with left ventricular assist devices, there are sex differences in adverse events. These devices do successfully bridge women and men to transplant, yet women are less likely than men to have a left ventricular assist at time of listing and time of transplantation. Finally, one will learn about the concerns regarding poor outcome for men who receive female donor hearts and discover this may not be due to sex, but rather size. More research is needed to better understand sex differences and further improve advanced heart failure therapy for both women and men.

Sex-Specific Outcome Disparities in Patients Receiving Continuous-Flow Left Ventricular Assist Devices: A Systematic Review and Meta-analysis

Continuous-flow left ventricular assist devices (CF-LVADs) decrease mortality and improve quality of life in patients with advanced heart failure (HF). Their widespread utilization has led to concerns regarding increased adverse effects, especially in women. Nevertheless, sex-specific data remain limited. We searched Medline, Embase, Scopus, and the Cochrane Library for publications reporting sex-specific outcomes after CF-LVADs from January 2008 through January 2017. Outcomes were compared under the random-effects model and heterogeneity examined via χ test and I statistics. A total of 10 studies including 4,493 CF-LVAD recipients were included in the analysis (23.5% women). The overall rate of stroke was significantly higher in women (odds ratio [OR] 1.94; 95% confidence interval [CI] 1.32-2.84; p = 0.0007). This was true for ischemic strokes (OR 2.03; 95% CI 1.21-3.42; p = 0.008) and hemorrhagic strokes (OR 2.03; 95% CI 1.21-3.42; p = 0.008). Women were also more likely to develop right HF necessitating right ventricular assist device (RVAD) implantation (OR 2.12; 95% CI 1.08-4.15; p = 0.03). Other adverse events including renal failure, bleeding, and device-related infection were comparable for both genders. The overall mortality while on CF-LVAD was similar in both groups (OR 1.05; 95% CI 0.81-1.36; p = 0.71). Our analysis suggests that women are at greater risk of significant complications such as cerebrovascular events and right HF necessitating RVAD after CF-LVAD implantation. Further research is needed to better understand the mechanisms underlying these sex-specific outcome disparities.

Left Ventricular Assist Device Infections: A Systematic Review

Left ventricular assist devices (LVADs) are becoming a more frequent life-support intervention. Gaining an understanding of risk factors for infection and management strategies is important for treating these patients. We conducted a systematic review and meta-analysis of studies describing infections in continuous-flow LVADs. We evaluated incidence, risk factors, associated microorganisms, and outcomes by type of device and patient characteristics. Our search identified 90 distinct studies that reported LVAD infections and outcomes. Younger age and higher body mass index were associated with higher rates of LVAD infections. Driveline infections were the most common infection reported and the easiest to treat with fewest long-term consequences. Bloodstream infections were not reported as often, but they were associated with stroke and mortality. Treatment strategies varied and did not show a consistent best approach. LVAD infections are a significant cause of morbidity and mortality in LVAD patients. Most research comes from secondary analyses of other LVAD studies. The lack of infection-oriented research leaves several areas understudied. In particular, bloodstream infections in this population merit further research. Providers need more research studies to make evidence-based decisions about the prevention and treatment of LVAD infections.

Prognostic implications of serial outpatient blood pressure measurements in patients with an axial continuous-flow left ventricular assist device

BACKGROUND

Elevated blood pressure (BP) has been linked to adverse events during left ventricular assist device support. In this study we investigated the association between outpatient BP and stroke or suspected pump thrombosis among HeartMate II (HMII) recipients.

METHODS

We retrospectively studied 220 HMII patients. Serial outpatient BP measurements were averaged. Patients were categorized by: (1) mean arterial pressure (MAP), high (>90 mm Hg) vs intermediate (80 mm Hg ≤ MAP ≤ 90 mm Hg) vs low (<80 mm Hg); (2) systolic BP (SBP), high (≥101 mm Hg, median) vs low; and (3) pulse pressure (PP), high (≥22 mm Hg, median) vs low. To assess visit-to-visit BP variability, patients were divided in quartiles of standard deviation of MAP and SBP. The primary end-point was the composite of stroke or suspected pump thrombosis.

RESULTS

The risk for the primary end-point was increased in the high MAP group (adjusted hazard ratio [HR] 2.75, 95% confidence interval [CI] 1.49 to 5.05, vs intermediate MAP; and 6.73, 1.9 to 23.9, vs low MAP). MAP had higher predictive value for the primary end-point compared with SBP (p = 0.05). Patients with high SBP had a higher rate of stroke (HR 2.8, 95% CI 1.09 to 7.17, vs low SBP). The combination of high SBP and low PP was associated with the highest risk for stroke. The lowest quartile of visit-to-visit MAP variability was associated with the highest risk for the primary end-point.

CONCLUSIONS

Elevated outpatient BP is associated with increased risk for stroke or suspected pump thrombosis in HMII recipients. Reduced PP and low visit-to-visit BP variability may confer additional risk.

Sex-related differences in chronic heart failure

The prevalence of chronic heart failure (CHF) is steadily increasing. Both sexes are affected, with significant differences in etiology, epidemiology and clinical presentation, prognosis, comorbidities, and response to treatment. Women tend to develop CHF at a more advanced age, present more often with HF with preserved ejection fraction, are more symptomatic, and have a worse quality of life than men, but also a better prognosis. In women, CHF has more frequently a non-ischemic etiology, and arterial hypertension and diabetes mellitus are leading comorbidities. Furthermore, many sex-related differences have been detected in the response to treatment, for example a greater prognostic benefit from angiotensin-receptor blockers in women, a higher incidence of complications after defibrillator implantation, and a greater response to cardiac resynchronization therapy. Furthermore, women are less likely to receive defibrillator therapy or heart transplantation. The significant underrepresentation of women in clinical trials limits our capacity to evaluate the extent of sex-related differences in CHF, although their characterization seems crucial in order to achieve the ultimate goal of a tailored therapy for this condition.

The 50/50 cc Total Artificial Heart Trial: Extending the Benefits of the Total Artificial Heart to Underserved Populations

While use of the total artificial heart (TAH) is growing, the use of the device is not uniform across the gender and age spectrum because the vast majority of implants are in adult males. SynCardia has recently developed a smaller 50 cc TAH that was designed to accommodate patients with a body surface area as low as 1.2 m² (potentially even lower using virtual implantation). Herein, we describe the early use of the 50 cc TAH (10 implants in the US and 18 outside the US). Twenty-eight devices have been implanted worldwide. Nineteen (68%) patients were female, 4 (14%) were 21 years of age or younger, and 2 (7%) had a diagnosis of congenital heart disease (1 Fontan). The smallest patient, by body surface area, was 1.35 m². Six patients (21%) have been placed on the Freedom Driver, all of whom have survived. Fourteen patients (50%) have had a positive outcome to date. The development of the 50 cc TAH has expanded the population of patients who may benefit from TAH support and thus may help improve outcomes for patients who have had limited biventricular support options to date.

Surgical management of driveline infections in patients with left ventricular assist devices

BACKGROUND AND AIM OF THE STUDY

Driveline infections in patients with implantable left ventricular assist devices (VAD) carry increasing risk for pump infection, thromboembolic events, decreased quality of life, and increased hospitalization. We report our experience with a surgical technique for refractory driveline infections without mediastinitis consisting of translocation and wrapping of the driveline with greater omentum tissue.

METHODS

We retrospectively reviewed data of VAD patients who underwent surgical treatment by translocation and wrapping with omentum for severe chronic driveline infection.

RESULTS

Thirteen patients were treated between January 2010 and October 2015; 12 (92%) were male, and the mean age was 56 ± 14 years. Ten patients (77%) were managed with driveline sheathing with omentum and repositioning with a new exit site, and three (23%), suffering from driveline fistula, with driveline covering with omentum maintaining the previous exit site. Three episodes of postoperative bleeding (23%) required surgical revision. Twelve patients (92%) were discharged from the hospital and one (8%) died. Nine patients (69%) were free from infection at the time of discharge, and three (23%) had recurrence of infection within the first postoperative year. Only four patients (31%) required admission to the intensive care unit; overall median hospital stay was 23 days (range 7-205 days).

CONCLUSIONS

Driveline relocation with use of omentum is a feasible and effective procedure in selected cases of chronic severe driveline infection. The risk for perioperative bleeding should be taken into consideration and carefully monitored.

Sex differences and in-hospital outcomes in patients undergoing mechanical circulatory support implantation

BACKGROUND

Mechanical circulatory support (MCS) is a widely available management strategy. No studies have described sex differences in both extracorporeal and durable MCS. We analyzed sex-related differences of in-hospital outcomes for extracorporeal and durable MCS using administrative hospital data.

METHODS

In total, 134.5 million hospital records between 1994 and 2012 were screened for placement of MCS using procedure codes of the International Classification of Diseases-9, Clinical Modification. Major adverse events (MAEs) were defined as death, major bleeding, stroke, device infection or mechanical complication. Participation in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry was determined on an annual basis using quarterly reports of the INTERMACS. Associations between characteristics and outcomes were determined using multivariable logistic regression.

RESULTS

Sex was reported in 3,523 of 4,337 patients undergoing MCS placement from 45 INTERMACS sites (n = 1,383) and 246 non-INTERMACS sites (n = 2,954). Twenty-two percent were female. Baseline characteristics were significantly different with women being slightly younger (33.5% vs 27.4% age <50 years, p < 0.001; mean 55.7 ± 17.3 vs 56.1 ± 14.6 years) with fewer comorbidities. Women had higher rates of in-hospital mortality (52.3% vs 40.8%, p < 0.001) and MAEs (64.8% vs 52.5%, p < 0.001). Women had an 89% higher likelihood of MAEs when corrected for multivariate predictors (p < 0.001). In-hospital mortality decreased over time for both men and women (10% relative risk reduction/year, p < 0.001), but mortality in women was higher than in men throughout the study period.

CONCLUSION

There are significant sex differences in characteristics and outcomes of patients receiving MCS. Women had higher in-hospital mortality and were at increased risk of MAEs, which could not be explained by age or comorbid conditions. Further research on the causes of these disproportionate outcomes is needed.

Clinical and gender differences in heart transplant recipients in the NEW HEART study

BACKGROUND

Little attention has focused on gender differences in cardiac comorbidities and outcomes in patients undergoing orthotropic heart transplant.

OBJECTIVE

The objective of this study was to investigate gender differences at baseline and during follow-up among heart transplant patients.

METHODS

An observational cohort within the NEW HEART study was evaluated to determine gender differences in relation to age, coexisting cardiac comorbidities, and outcomes. Differences were assessed by t-test, Fisher's exact test, and logistic regression analysis.

RESULTS

Male transplant recipients ( n = 238) were significantly older than female recipients ( n = 92), with a greater percentage over 60 years of age (45% vs. 24%, p = 0.0006). Males were more likely to have hypertension (63% vs. 49%, p = 0.034), dyslipidemia (62% vs. 45%, p = 0.006), a history of smoking (52% vs. 35%, p = 0.009), and diabetes (42% vs. 21%, p = 0.0002). Analysis of endomyocardial biopsies obtained during the 1-year follow-up period demonstrated that women averaged more episodes of acute rejection than men (3.9 vs. 3.0, p = 0.009). While most episodes of rejection were mild, women were more likely than men to have episodes of moderate or severe rejection (14% vs. 5%, p = 0.012) and to be hospitalized for acute rejection (15% vs. 6%, p = 0.013). There were no significant differences in mortality.

CONCLUSIONS

Men were more likely than women to be older and to have diabetes, dyslipidemia, hypertension, and a history of smoking. Women were more likely to experience moderate or severe allograft rejection and to be hospitalized for acute rejection. Future investigation of the reasons for these gender differences is warranted and may improve clinical care of women undergoing cardiac transplantation.