Characterizing Adaptive Changes and Patient Survival after 2018 Donor Allocation Restructuring: A UNOS Database Analysis

PURPOSE

We sought to characterize adaptive changes to the revised UNOS donor heart allocation policy and estimate long-term survival trends for heart transplant (HTx) recipients.

METHODS

Patients listed for HTx between 10/17/2013 and 9/30/2021 were identified from the UNOS database and stratified into pre- and post-policy revision groups. Sub-analyses were performed to examine trends in device utilization for extracorporeal membranous oxygenator (ECMO), durable left ventricular assist device (LVAD), intra-aortic balloon pump (IABP), microaxial support (Impella), and no mechanical support (non-MCS). Survival data post-HTx were fitted to parametric distributions and extrapolated to five years.

RESULTS

We identified 28,506 HTx waitlist candidates during the study period, most of whom (n=19,067) were waitlisted in the pre-policy change period. Overall, 18,252 patients underwent HTx during the study period (Pre: 12,656, Post: 5,596). Listings increased after the policy change for ECMO (p<0.01), IABP (p<0.01) and Impella (p<0.01) patients. Listings for LVAD (p<0.01) and non-MCS (p<0.01) patients decreased. HTx increased for ECMO (p<0.01), IABP (p<0.01), and Impella (p<0.01) patients after the policy change and decreased for LVAD (p<0.01) and non-MCS (p<0.01) patients. Waitlist survival increased for the overall (p<0.01), LVAD (p<0.05) and non-MCS (p<0.01) groups but decreased for ECMO (p<0.01) and IABP (p= 0.05) patients. Post-transplant survival decreased for the overall (p<0.01), LVAD (p<0.01), IABP (p<0.05), Impella (p<0.01), and non-MCS (p<0.01) populations but increased for ECMO (p<0.05) patients.

CONCLUSIONS

Allocation policy revisions have contributed to greater utilization of ECMO, Impella, and IABP, decreased utilization of LVADs and non-MCS, increased waitlist survival, and decreased post-HTx survival.

Next Generation Development of Hybrid Continuous Flow Pediatric Total Artificial Heart Technology: Design-Build-Test

To address the unmet clinical need for pediatric circulatory support, we are developing an operationally versatile, hybrid, continuous-flow, total artificial heart ("Dragon Heart"). This device integrates a magnetically levitated axial and centrifugal blood pump. Here, we utilized a validated axial flow pump, and we focused on the development of the centrifugal pump. A motor was integrated to drive the centrifugal pump, achieving 50% size reduction. The motor design was simulated by finite element analysis, and pump design improvement was attained by computational fluid dynamics. A prototype centrifugal pump was constructed from biocompatible 3D printed parts for the housing and machined metal parts for the drive system. Centrifugal prototype testing was conducted using water and then bovine blood. The fully combined device ( i.e. , axial pump nested inside of the centrifugal pump) was tested to ensure proper operation. We demonstrated the hydraulic performance of the two pumps operating in tandem, and we found that the centrifugal blood pump performance was not adversely impacted by the simultaneous operation of the axial blood pump. The current iteration of this design achieved a range of operation overlapping our target range. Future design iterations will further reduce size and incorporate complete and active magnetic levitation.

Utilization and outcomes of V-AV ECMO: A systematic review and meta-analysis

BACKGROUND

Veno-arterial-venous extracorporeal membrane oxygenation (V-AV ECMO) is a less commonly used configuration of ECMO. We sought to understand the indications, utilization patterns, and outcomes of V-AV ECMO by quantitatively pooling the existing evidence from the literature.

METHODS

Electronic search was performed to identify all relevant studies reporting V-AV ECMO usage. Five studies comprising 77 patients were selected and cohort-level data were extracted for further analysis.

RESULTS

Mean patient age was 61 (95% CI: 55.2, 66.5) years and 30% (23/77) were female. The majority of cases [91% (70/77)] were transitioned to V-AV ECMO from another pre-existing ECMO configuration: V-A ECMO in 55% (42/77) vs. V-V ECMO in 36% (28/77), p = 0.04. Only 9% (7/77) of cases were directly placed on V-AV ECMO. The mean duration of hospital stay was 42.3 (95% CI: 10.5, 74.2) days, while ICU mortality was 46% (29, 64). Transition to durable left ventricular assist device was performed in 3% (2/64) of patients, while 3% (2/64) underwent heart transplantation. V-AV ECMO was successfully weaned to explantation in 33% (21/64) of patients.

CONCLUSION

V-AV ECMO is a viable option for optimizing cardiopulmonary support in selected patients. Survival to weaning or bridging therapy appears comparable to more common ECMO configurations.

Hepatitis B in Heart Transplant Donors and Recipients: A Systematic Review and Meta-Analysis

INTRODUCTION

Expanding the heart donor pool to include patients with hepatitis B virus (HBV) could help ameliorate the organ shortage in heart transplantation. We performed a systematic review and meta-analysis to evaluate the management and recipient outcomes of D+/R- and D-/R+ heart transplants.

METHODS

An electronic search was performed to identify all relevant studies published on heart transplants involving HBV+ donors and/or HBV+ recipients. A comparison was performed between two groups where heart transplants were performed a) D+/R- (n = 98) versus b) D-/R+ (n = 65).

RESULTS

Overall, 13 studies were selected, comprising 163 patients. Mean patient age was 55 y (95% CI: 39, 78) and 79% (69, 86) were male. Active post-transplant HBV infection requiring antiviral treatment occurred in 11% (1, 69) of D+/R- recipients and 33% (9, 71) of D-/R+ recipients. Post-transplant antiviral therapy was given to 80% (6, 100) of D+/R- recipients compared to 72% (42, 90) of D-/R+ recipients (P = 0.84). Hepatitis-related mortality was observed in no D+/R- recipients and 7% (2, 27) of D-/R+ recipients. Survival 1-y post-transplant was comparable between both groups at 83% (83, 92) and 81% (61, 92) for D+/R- and D-/R+ transplants, respectively.

CONCLUSIONS

Our review found that HBV D+/R- heart transplantation was associated with fewer active hepatitis infections and lower hepatitis-related mortality than D-/R+ transplantation, with comparable survival at 1 y. Additional studies utilizing HBV nucleic acid testing (NAT) to compare outcomes with HBsAg+ and anti-HBc+ donors are crucial to reach more definitive conclusions about the risk of donor-derived infections in this context.

Percutaneous Decommissioning 11 Years After Initial CF-LVAD Placement

An 80-year-old man with severe nonischemic cardiomyopathy status post left ventricular assist device (LVAD) placement 11 years prior presented for recurrent LVAD alarms from internal driveline fracture. Given his partial myocardial recovery and his preference to avoid surgical procedures, percutaneous LVAD decommissioning was performed by occlusion of the outflow graft and subsequently driveline removal. (Level of Difficulty: Advanced.)

Continuous-flow left ventricular assist devices associated survival awaiting heart and heart-kidney transplant

BACKGROUND

Improvement in continuous-flow left ventricular assist device (CF-LVAD) technology has translated to better outcomes for patients on CF-LVAD support as a bridge-to-transplant. However, data are lacking regarding the subset of CF-LVAD patients with renal failure awaiting simultaneous heart-kidney transplant (HKTx). We sought to better understand the characteristics and outcomes of patients in this group.

METHODS

The United Network for Organ Sharing (UNOS) database was used to identify adult patients listed for heart transplant (HTx) or HKTx from January 1, 2009 to March 31, 2017. Patients were followed from time on waitlist to either removal from waitlist or transplantation. Demographic and clinical data for HTx and HKTx patients were assessed. Kaplan-Meier analysis assessed waitlist and post-transplant survival. For waitlisted patients, both death and removal from the waitlist due to deteriorating medical condition were considered events.

RESULTS

Overall, 26 638 patients registered for transplant were analyzed. 25 111 (94%) were listed for HTx, and 1527 (6%) for HKTx. 7683 (29%) patients listed for HTx had CF-LVAD support. For those listed for HKTx, 441 (28%) underwent dialysis alone, 256 (17%) had CF-LVAD support alone, and 85 (6%) were treated with both CF-LVAD and dialysis. 15 567 (58%) underwent HTx, and 621 (2%) underwent HKTx. In these groups, post-transplant survival was similar (p = 0.06). Patients listed for HKTx treated with both dialysis and CF-LVAD had significantly worse waitlist survival compared to HKTx recipients (p < 0.001).

CONCLUSION

Post-transplant survival is comparable between HTx and HKTx, and early survival is similar between HTx patients and those listed for HTx with CF-LVAD support. However, outcomes on the waitlist for HKTx in CF-LVAD patients on dialysis is significantly worse compared to HKTx recipients. This highlights the need to better account for this patient population when allocating organs.

Infection following CF-LVAD exchange for non-infectious indications: A systematic review and meta-analysis

Introduction:

Patients on continuous flow left ventricular assist devices (CF-LVADs) often require CF-LVAD exchange. The purpose of this study was to investigate the incidence of infection following CF-LVAD exchange performed for non-infectious indications.

Methods:

An electronic literature search was performed to identify all studies of patients undergoing CF-LVAD exchange for pump thrombosis or device malfunction. Of 2,698 articles identified, 6 studies with 81 total patients met the inclusion criteria. Cohort-level data were pooled for meta-analysis.

Results:

Mean patient age was 60 years (95% CI: 41–78), and 74% were male (95% CI: 61–84). Pump thrombosis was the most common indication for exchange in 70% of patients (95% CI: 47–86). Other indications were driveline fracture and electrical malfunction in 21% (95% CI: 5–56) and 12% (95% CI: 4–33) of patients, respectively. Prior to exchange, 95% of patients were on HeartMate II (HM2) LVADs (95% CI: 86–98) and average duration of support for these patients was 27.1 months (95% CI: 9.3–44.8). The majority were placed on a HM2 following exchange (88% (95% CI: 45–98)) versus HM3 (12% (95% CI: 2–55)). Follow-up was an average of 16.4 months (95% CI: 6.8–26.0). Following exchange, 16 of 81 patients developed infection, with pooled mean incidence of 24% (95% CI: 14–38). 30-day mortality was 14% (95% CI: 7–26). Survival at follow-up was 65% (95% CI: 52–76).

Conclusions:

Infection following CF-LVAD exchange can occur at rates higher than those observed with primary implantation; therefore, effective strategies need to implemented early and consistently to help lower infections rates and help improve outcomes following exchange.

Evaluation of donor heart for transplantation

Cardiac transplantation is considered the gold-standard treatment option for patients suffering from end-stage heart failure refractory to maximum medical therapy. A major determinant of graft function and recipient survival is a comprehensive evaluation of the donor allograft. Challenges arise when designing and implementing an evidence-based donor evaluation protocol due to the number of influential donor-specific characteristics and the complex interactions that occur between them. Here, we present our systematic approach to donor evaluation by examining the impact that relevant donor variables have on graft function and recipient outcomes.

Cardiac transplantation after heparin induced thrombocytopenia: A systematic review

PURPOSE

Heparin induced thrombocytopenia (HIT) presents a unique challenge in patients requiring orthotopic heart transplantation (OHT). We sought to pool the existing evidence in a systematic review.

METHODS

Electronic search was performed to identify all relevant studies on OHT in patients with HIT. Patient-level data for 33 patients from 21 studies were extracted for statistical analysis.

RESULTS

Median patient age was 51 [41, 55] years, with 75.8% (25/33) males. All patients had a clinical diagnosis of HIT, and anti PF4/Heparin antibodies were positive in 87.9% (29/33). Median lowest reported platelet count was 46 × 10⁹ /L [27.2, 73.5]. Intraoperatively, 61% (20/33) of patients were given unfractionated heparin (UFH), while 39% (13/33) were given alternative anticoagulants. The alternative agent subgroup required more antifibrinolytics [54% (7/13) vs. 10% (2/20), p = 0.02] and clotting factors [69.2% (9/13) vs. 15.0% (3/20) p<0.01]. Peri-operative thrombosis occurred more in [53.8% (7/13) vs 0% (0/20, p<0.01) alternate agent subgroup. More patients in the alternate agent subgroup required post-operative transfusions [54% (7/13) vs. 0% (0/20), p<0.01]. Thirty-day mortality of 15.2% (5/33) was comparable between the subgroups.

CONCLUSION

Heparin use during OHT may be associated with less adverse effects compared to use of other anticoagulants with no difference in 30-day mortality. This article is protected by copyright. All rights reserved.

Survival outcomes of stenting outflow graft stenosis in continuous-flow left ventricular assist devices: a systematic review

Stenosis in the continuous-flow left ventricular assist device (CF-LVAD) outflow graft is caused by various factors. We discuss indications for percutaneous intervention of outflow graft complications and evaluate the use of this treatment in re-establishing adequate CF-LVAD flow. An electronic search was performed to identify all studies in the English literature reporting CF-LVAD outflow graft stenting. Twenty-one studies consisting of 26 patients were included. Patient-level data were extracted for statistical analysis. Median patient age was 59 years [45.8-67.0] and 65.4% (17/26) were male. 58.3% (14/24) of patients had HeartWare HVAD, 37.5% (9/24) had HeartMate II LVAD, and 4.2% (1/24) had HeartMate III LVAS. Median time from device placement to outflow graft stenting was 24.0 months [7.8-30.4]. 76.9% of patients (20/26) presented with heart failure. Complications of the CF-LVAD outflow graft included thrombosis in nine patients (34.6%), stenosis in nine patients (34.6%), kinking in three patients (11.5%), pseudoaneurysm in one patient (3.8%), external graft compression in one patient (3.8%), and bronchial-arterial fistula in one patient (3.6%). Immediate flow improvement occurred in 23/26 patients (88.5%), with the remaining 11.5% (3/26) requiring additional procedures. Pre- and post-intervention flows were 2.9 L/min [2.0-3.5] and 4.7 L/min [4.1-4.8] respectively (p = 0.01). Of patients, 96.2% (25/26) were discharged with a median time to discharge of 4 days [3.0-5.0]. The 30-day mortality was 6.7% (1/15). Overall mortality during the median follow-up of 90 days was 9.5% (2/21). Outflow graft stenting appears to effectively alleviate CF-LVAD outflow graft obstruction and is associated with low overall mortality.

Tricuspid regurgitation associated with implantable electrical device insertion: A systematic review and meta-analysis

BACKGROUND

Implantable cardioverter defibrillator (ICD) and permanent pacemaker (PPM) lead placement may worsen or result in tricuspid regurgitation (TR). While the association between lead placement and the incidence of TR has been established, current understanding of this problem remains incomplete. This systematic review and meta-analysis sought to pool the existing evidence to better understand the occurrence and severity of TR associated with cardiac implantable electrical device (CIED) insertion.

METHODS

An electronic search was performed to identify all relevant studies published from 2000 to 2018. Overall, 15 studies were selected for the analysis comprising 4019 patients with data reported on TR development following ICD or PPM lead placement. Demographic information, perioperative clinical variables, and clinical outcome measures, including pre and postoperative echocardiographic TR grade changes, were extracted and pooled for systematic review.

RESULTS

Mean patient age was 69 years [95% CI: 64.62-73.59], and 63% [95% CI: 57-68] were male. Devices implanted included ICD in 57% [95%CI: 43-70] and PPM in 41% [95%CI: 31-52]. The most common indications for pacemaker implantation were sick sinus syndrome in 22% [95% CI: 22-37] and AV block in 21% [95%CI:12-34. The commonest indications for ICD implantation were primary and secondary prevention of sudden cardiac death. Atrial fibrillation was present in 37% [95%CI: 28-46] and congestive heart failure in 15% [95%CI: 2-57]. Baseline distribution of TR grades were as follows: grade 0/1 TR in 89% [95%CI: 82-93], grade 2 TR in 8% [95%CI: 5-13], grade 3 TR in 2% [95%CI: 0-7] and grade 4 TR in 2% [95%CI: 1-4]. Post-procedure, grade 0/ 1 TR decreased to 68% [95% CI: 51-81] (p < 0.01), grade 2 TR increased to 21% [15-28] (p < 0.01), grade 3 TR increased to 13% [95%CI: 5-32] (p = 0.02), and grade 4 TR increased to 7% [95%CI: 5-9] (p < 0.01).

CONCLUSION

ICD and PPM lead placement is associated with increased TR post-procedure. Further studies are warranted to evaluate changes in TR grade in the long term.

Development of malignancies and their outcomes in patients supported on continuous-flow left ventricular assist devices-a systematic review

Background

With increased use of continuous-flow left ventricular assist devices (CF-LVAD), development of malignant tumors in this population is not uncommon. We sought to evaluate malignancies in CF-LVAD patients and evaluate the outcomes of treatment strategies.

Methods

Overall, 18 articles consisting of 28 patients were identified who developed malignancies after CF-LVAD placement. Patient-level data were extracted for systematic review.

Results

Median patient age was 60 years [59-67] and 85.7% (24/28) were male. CF-LVAD was placed as bridge-to-transplant (BTT) in 60.9% (14/23) of patients. The three most common malignancy types were GI in 35.7% (10/28) of patients, lung in 21.4% (6/28) and skin in 10.7% (3/28). Median time from CF-LVAD implant to malignancy diagnosis was 6.9 [2.5-12.8] months. Metastatic disease occurred in 17.9% (5/28) over a median time of 5.0 [1.0-82.0] months from the diagnosis. Surgical resection of the malignancy was performed in 57.1% (16/28) of patients. Our results showed that while there was a significantly higher probability of survival among patients who underwent surgery versus those who did not, when only stage I and II patients were included in the analysis, this difference was no longer statistically significant. Three patients were relisted for heart transplant after surgical treatment, and two received the transplant.

Conclusions

Surgical management of malignancies in patients on CF-LVADs may improve survival and transplant eligibility status, therefore, a CF-LVAD should not always preclude surgical treatment.

Computational sentiment analysis of an online left ventricular assist device support forum: positivity predominates

Background

The impact of left ventricular assist device (LVAD) complications on the individual patient, overall sentiment, and its effect on referral patterns, is not fully understood. We sought to better understand patient attitudes towards LVAD therapy using a computational sentiment analysis approach.

Methods

Posts, comments, and titles were parsed from MyLVAD.com's HTML as a text file using custom Python scripts (version 3.6). Individual word frequency was computed with word classification as 'positive', 'negative', or 'neutral'. Data transformation and cleaning, sentiment determination, and analysis was performed with a binary dictionary package using R software (version 3.6).

Results

Sixty-six thousand eight hundred and twenty-one unique words were noted, including 4,623 (6.9%) with positive sentiment and 3,248 (4.8%) with negative sentiment. Net sentiment ratio [(number of positive words - number of negative words)/(number of total words)] was 2.1%. Positive sentiment dominated the 20 most commonly used words. Odds ratio of non-neutral words [(number of positive words/number of negative words)] was 1.42, indicating a less obvious disparity in sentiment when expanding analysis beyond the top 20 words. Word cloud analysis of positive and negative sentiments was performed, indicating common use of "infection" (208 mentions) compared to other complications such as "stroke" (29 mentions), "bleeding" (30 mentions), and "thrombosis" or "clot" (32 mentions).

Conclusions

Positive sentiment dominates the most frequently used words, yet this disparity decreases when considering the totality of words. "Infection" is mentioned a disproportionate number of times compared to other LVAD complications. Further research is required to address analysis limitations, including selection bias.

Outcomes of surgical treatment for carcinoid heart disease: A systematic review and meta-analysis

BACKGROUND

Carcinoid heart disease (CaHD) develops from vasoactive substances released by neuroendocrine tumors, which can cause significant patient morbidity and mortality without surgical intervention. We performed a systematic review and meta-analysis to elucidate granular perioperative details and long-term outcomes in these patients.

METHODS

Electronic search of Ovid, Scopus, Cumulative Index of Nursing and Allied Health Literature, and Cochrane Controlled Trials Register was performed to examine surgical treatment of carcinoid disease. Nine articles comprising 416 patients were selected. Study-level data were extracted and pooled for meta-analysis.

RESULTS

Mean patient age was 63 years (95% confidence interval, 57-70) with 53% (95% confidence interval, 46-61) of patients being male. In addition, 75% (95% confidence interval, 54-96) of neuroendocrine tumors originated from the small bowel or colon and 98% (95% confidence interval, 93-100) had liver metastases. Right heart failure was present in 48% (95% confidence interval, 14-81). Moderate or severe regurgitation was present in 97% (95% confidence interval, 95-99) of tricuspid and 72% (95% confidence interval, 58-83) of pulmonary valves. In addition, 99% (95% confidence interval, 98-100) of tricuspid and 59% (95% confidence interval, 38-79) of pulmonary valves were replaced. Bioprosthetic valves were used in 80% (95% confidence interval, 68-93) of tricuspid positions. Mean hospital duration of stay was 16 days (95% confidence interval, 7-25). Thirty-day mortality was 9% (95% confidence interval, 6-12). Mean follow-up was 25 months (95% confidence interval, 11-39). Median survival was 3 years (95% confidence interval, 2.5-3.5).

CONCLUSION

For patients >18 years of age, surgical treatment of carcinoid heart disease can be performed with a reasonable safety profile. However, overall survival appears to have ongoing effects of the primary disease.

Driveline damage and repair in continuous-flow left ventricular assist devices: A systematic review

With mounting time on continuous-flow left ventricular assist device (CF-LVAD) support, patients occasionally sustain damage to the device driveline. Outcomes associated with external and internal driveline damage and repair are currently not well documented. We sought to evaluate the outcomes of driveline damage and its repair. Electronic search was performed to identify all relevant studies published over the past 20 years. Fifteen studies were selected for analysis comprising of 55 patients with CF-LVAD dysfunction due to driveline damage. Demographic and perioperative variables along with outcomes including survival rates were extracted and pooled for the systematic review. Most patients (53/55) were supported on HeartMate II LVAD (Abbott Laboratories, Abbott Park, IL). Internal damage was more commonly reported than external damage [69.1% (38/55) vs. 30.9% (17/55), P = .01]. Median time to driveline damage was 1.9 years [IQR 1.0, 2.5]. Most patients presented with a CF-LVAD alarm [94.5% (52/55)] and patients with internal driveline damage had a significantly higher rate of alarm activation compared to that observed for those with external damage [38/38 (100%) vs. 14/17 (82.4%), P = .04]. Patients with internal driveline dysfunction were more likely to experience component wear compared to those with external driveline dysfunction [10/38 (26.3%) vs. 0/17 (0%), P = .05]; 14.5% of patients (8/55) underwent external repair of the driveline, 5.5% (3/55) were treated with rescue tape, and 5.5% (3/55) were placed on an ungrounded cable, indicating a short-to-shield event had occurred. A total of 49.1% of patients (27/55) underwent CF-LVAD exchange, 5.5% (3/55) were weaned off the CF-LVAD to explant, and 5.5% (3/55) underwent emergent heart transplantation. The median length of hospital stay was 12 days [IQR 7, 12] and 30-day mortality rate was 14.5% (8/55). Driveline damage was more commonly reported at an internal location and despite being a well-recognized complication, mortality still appears high.

Evaluation of Endovascular Intervention for Tracheo-Innominate Artery Fistula: A Systematic Review

BACKGROUND

While the standard of care for suspected tracheo-innominate artery fistula (TIF) necessitates sternotomy, perioperative mortality remains high. Endovascular interventions have been attempted, but reports have been anecdotal. The aim of this systematic review was to evaluate the outcomes of endovascular management of TIF by pooling the existing evidence.

METHODS

An electronic database search of Ovid MEDLINE, Scopus, Cumulative Index to Nursing and Allied Health Literature, and Cochrane Controlled Trials Register was performed to identify all studies examining endovascular treatment of TIF. Patients greater than 14 years of age who underwent endovascular intervention for TIF were included. 25 studies consisting of 27 patients met the inclusion criteria.

RESULTS

48.1% (13/27) of patients were male and median age was 39.0 [IQR 16.0, 47.5] years. Tracheostomy was present in 96.3% (26/27) of cases. Median duration from tracheostomy to TIF presentation was 2.2 months [0.5, 42.5]. On presentation, 84.6% (22/26) had tracheal hemorrhage, and 22.8% (6/27) were hemodynamically unstable. 96.3% (26/27) underwent covered stent graft placement while 1 patient (3.8%) had coil embolization. 18.5% (5/27) of patients required repeat endovascular intervention for recurrent bleeding, while 11.1% (3/27) required rescue sternotomy. Median hospital length of stay was 30 days [16.0, 46.5], and overall mortality was 29.6% (8/27) with a median follow-up time of 5 months [1.2, 11.5].

CONCLUSION

While uncommon, endovascular treatment of TIF may be a feasible alternative to sternotomy. The approach may be useful in those who are unable to undergo surgery or are likely to have adhesions from prior chest operations.

Utilization of extracorporeal life support for diffuse alveolar damage and diffuse alveolar hemorrhage: A systematic review

Modern extracorporeal life-support (ECLS) technology has been successfully utilized to treat patients with diffuse alveolar damage (DAD) and diffuse alveolar hemorrhage (DAH); however, reports in the literature remain scarce. We sought to pool existing evidence to better characterize ECLS use in these patients. An electronic search was conducted to identify all studies in the English literature reporting the use of ECLS for DAD/DAH. Thirty-two articles consisting of 38 patients were selected, and patient-level data were extracted and pooled for analysis. Median patient age was 36 [IQR: 27, 48] years, and the majority (63.2%) were female. Most common etiological factors included granulomatosis with polyangiitis (8/38, 21.1%), systemic lupus erythematosus (8/38, 21.1%), Goodpasture's syndrome (4/38, 10.5%), and microscopic polyangiitis (4/38, 10.5%). Immunologic markers included anti-neutrophil cytoplasmic antibody (ANCA) in 15/38 (39.5%), anti-nuclear antibody (ANA) in 6/38 (15.8%), and anti-glomerular basement membrane (anti-GBM) antibodies in 4/38 (10.5%). DAH was present in 32/38 (84.2%) of cases and DAD without evidence of DAH was present in 6/38 (15.8%) of cases. ECLS strategies included extracorporeal membrane oxygenation of veno-venous type (VV-ECMO) in 28/38 (73.7%), veno-arterial type (VA-ECMO) in 5/38 (13.2%), and one case of right ventricular assist device with oxygenator (RVAD-ECMO). Heparin was utilized in 18/38 (47.4%) of cases with no difference in use between DAH versus no DAH (P = .46) or VA- versus VV-ECLS (P = 1). Median duration of ECLS was 10 [5, 14] days. Pre- versus post-ECLS comparison of blood gases showed improvement in median PaO₂ (49 [45, 59] mm Hg vs. 80 [70, 99] mm Hg, P < .001), PaO2:FiO₂ ratio (48.2 [41.4, 54.8] vs. 182.0 [149.4, 212.2], P < .01), and pulse oximetry values (76% [72, 80] vs. 96% [94, 97], P = .086). Overall, 94.7% (36/38) of patients survived to decannulation while 30-day mortality was 10.5% (4/38) with no differences between VA- and VV-ECMO (P = 1 and P = .94, respectively). DAD/DAH occurs in a younger, predominantly female population, and tends to be associated with systemic autoimmune processes. ECLS, independent of its type, appears to result in favorable short-term survival.

Impact of mechanical circulatory support on donor heart allocation: past, present, and future

The United Network for Organ Sharing (UNOS) recently revised its heart allocation policy to address numerous shortcomings of the previous system. Implemented in 2018, the changes sought to reduce waiting list mortality, clearly define urgency status based on objective physiologic variables, decrease exemption requests, and introduce geographic modifications to ensure organ distribution favors the highest urgency candidates. In large part, UNOS policy revisions were driven by the growing use of continuous flow left ventricular assist devices (CF-LVADs) and the relevant device complications that led to an unacceptably high number of status exemptions. The new 6-tiered system assigns a comparatively lower urgency status to patients supported on CF-LVADs and higher urgency to patients supported on short-term mechanical circulatory assist (MCA) such as extracorporeal membrane oxygenation (ECMO) and intraaortic balloon pump (IABP) counterpulsation. LVAD use as bridge to transplant (BTT) therapy increased steadily throughout the preceding decade due to technological improvements and increased physician familiarity, but the recent policy changes introduce incentives for physicians to withhold this life-saving therapy in order to achieve higher urgency status for their patients. This paper will explore the technological evolution of MCA and the pertinent clinical trials that have led to their FDA approval as BTT and destination therapy. A review of the inception and development of the donor allocation system will be provided before examining available post-policy outcome data. Finally, we will highlight successes and shortcomings of the implemented changes before commenting on areas to potentially expand upon the existing policy.

Outcomes of Extracorporeal Life Support Use in Accidental Hypothermia: A Systematic Review

BACKGROUND

Extracorporeal life support (ECLS) has been used in the treatment of accidental hypothermia with hemodynamic instability, with promising outcomes. This systematic review examines ECLS treatment of accidental hypothermia to assess outcomes.

METHODS

An electronic search was performed to identify articles reporting ECLS use for treatment of accidental hypothermia. Only reports describing patients aged more than 16 years after January 1, 2005, were included. Nineteen studies were identified comprising 47 patients. Demographic information, perioperative variables, and outcomes were extracted for analysis.

RESULTS

Median patient age was 48 years (interquartile range (IQR), 29 to 56), and 72.3% (34 of 47) were male. On presentation, median body temperature was 24.6°C (IQR, 22.2° to 26°C), median potassium level 4.3 mmol/L (IQR, 3.4 to 4.6 mmol/L), and median Glasgow Coma Scale score 3 (IQR, 3 to 7). Cardiac arrest occurred in 35 of 47 patients (74.5%). Median time to ECLS initiation from scene was 155 minutes (IQR, 113 to 245). Median ECLS duration was 18 hours (IQR, 4 to 27), with median rewarming rate of 2°C per hour (IQR, 1.5° to 4°). Median intensive care unit stay and hospital length of stay were 8 days (IQR, 2 to 16) and 17 days (IQR, 10 to 36), respectively. Inhospital mortality was 19.1% (9 of 47). Median discharge Glasgow Coma Scale score was 15 (IQR, 15 to 15) with minor long-term cognitive impairments noted in 6 of 47 patients (19.4%). Survival was significantly associated with potassium on presentation (P < .001), initial body temperature (P < .001), and ECLS rewarming rate (P < .001).

CONCLUSIONS

Extracorporeal life support is a viable cardiac support option for rewarming patients with accidental hypothermia, and initial potassium level, initial body temperature, and ECLS rewarming rate appear to be significantly associated with survival.

Outcomes of percutaneous temporary biventricular mechanical support: a systematic review

Percutaneous biventricular assist devices (BiVAD) are a recently developed treatment option for severe cardiogenic shock. This systematic review sought to identify indications and outcomes of patients placed on percutaneous BiVAD support. An electronic search was performed to identify all appropriate studies utilizing a percutaneous BiVAD configuration. Fifteen studies comprising of 20 patients were identified. Individual patient survival and outcomes data were combined for statistical analysis. All 20 patients were supported with a microaxial LVAD, 12/20 (60%) of those patients were supported with a microaxial (RMA) right ventricular assist device (RVAD), and the remaining 8/20 (40%) patients were supported with a centrifugal extracorporeal RVAD (RCF). All patients presented with cardiogenic shock, and of these, 12/20 (60%) presented with a non-ischemic etiology vs 8/20 (40%) with ischemic disease. For the RMA group, RVAD support was significantly longer [RMA 5 (IQR 4-7) days vs RCF 1 (IQR 1-2) days, p = 0.03]. Intravascular hemolysis post-BiVAD occurred in three patients (27.3%) [RMA 3 (33.3%) vs RCF 0 (0%), p = 0.94]. Five patients received a durable left ventricular assist device, one patient received a total artificial heart, and one patient underwent a heart transplantation. Estimated 30-day mortality was 15.0%, and 78.6% were discharged alive. Both strategies for percutaneous BiVAD support appear to be viable options for severe cardiogenic shock.

Continuous-flow left ventricular assist device implantation in patients with preexisting mechanical mitral valves: a systematic review

Introduction: A preexisting mechanical mitral valve (MMV) is thought to be a thrombogenic risk factor after continuous-flow left ventricular assist device (CF-LVAD) implantation. We sought to evaluate the management and outcomes of preexisting MMVs in patients following CF-LVAD implantation.Areas covered: An electronic search was performed to identify the presence of an MMV at the time of CF-LVAD implantation. Of the 1,168 studies identified, only five studies consisting of seven CF-LVAD patients met the inclusion criteria. Patient-level data were extracted and analyzed.Expert opinion: The median patient age was 54 (IQR: 42-61) years and 71.4% (5/7) were male. Non-ischemic cardiomyopathy was the predominant etiology (83.3%, 5/6) of heart failure, and bridge-to-transplant the predominant indication (85.7%, 6/7) for CF-LVAD. Aortic valve prosthesis was present in 42.9% (3/7) of patients. Median time from MMV to CF-LVAD placement was 6.0 years (IQR: 1.3-15.0). The median lower limit of the INR range was 2.8 (IQR: 2.1-3.0) and upper limit of the INR range was 3.5 (IQR: 3.1-3.5). During a median follow-up time of 120 (IQR: 70-201) days, there were no major GI bleeds or clinically significant thromboembolic complications. With adequate anticoagulation, preexisting MMVs in CF-LVAD patients did not result in clinically significant thromboembolic events.

Repair of ischemic ventricular septal defect with and without coronary artery bypass grafting

BACKGROUND AND AIM OF THE STUDY

Ventricular septal defect (VSD) following myocardial infarction (MI) is a relatively infrequent complication with high mortality. We sought to investigate the effect of concomitant coronary artery bypass graft (CABG) on outcomes following post-MI VSD repair.

METHODS

Electronic search was performed to identify all relevant studies published from 2000 to 2018. Sixty-seven studies were selected for the analysis comprising 2174 patients with post-MI VSD. Demographic information, perioperative variables, and outcomes including survival data were extracted and pooled for systematic review and meta-analysis.

RESULTS

Single-vessel disease was most common (47%, 95% confidence interval [CI], 42-52), left anterior descending coronary artery was the most commonly involved vessel (55%, 95% CI, 46-63), and anterior wall was the most commonly affected territory (57%, 95% CI, 51-63). Concomitant CABG was performed in 52% (95% CI, 46-57) of patients. Of these, infarcted territory was re-vascularized in 54% (95% CI, 23-82). A residual/recurrent shunt was present in 29% (95% CI, 24-34) of patients. Of these, surgical repair was performed in 35% (95% CI, 28-41) and transcatheter repair in 11% (95% CI, 6-21). Thirty-day mortality was 30% (95% CI, 26-35) in patients who had preoperative coronary angiogram, and 58% (95% CI, 43-71) in those who did not (P < .01). No significant survival difference observed between those who had concomitant CABG vs those without CABG.

CONCLUSIONS

Concomitant CABG did not have a significant effect on survival following VSD repair. Revascularization should be weighed against the risks associated with prolonged cardiopulmonary bypass.

Domino heart transplant following heart-lung transplantation: a systematic review and meta-analysis

Background

The domino-donor operation occurs when a "conditioned" heart from the heart-lung transplant (HLT) recipient is transplanted into a separate heart transplant (HT) recipient. The purpose of this systematic review was to investigate the indications and outcomes associated with the domino procedure.

Methods

An electronic search was performed to identify all prospective and retrospective studies on the domino procedure in the English literature. Eight studies reported 183 HLT recipients and 263 HT recipients who were included in the final analysis.

Results

HLT indications included cystic fibrosis in 58% (95% CI: 27-84%) of recipients, primary pulmonary hypertension (PPH) in 17% (95% CI: 12-24%), bronchiectasis in 5% (95% CI: 3-10%), emphysema in 5% (95% CI: 0-45%), and Eisenmenger's syndrome in 4% (95% CI: 2-8%). HT indications included ischemic heart disease in 40% (95% CI: 33-47%), non-ischemic disease in 39% (95% CI: 25-56%), and re-transplantation in 10% (95% CI: 1-59%). The pooled mean pulmonary vascular resistance (PVR) in HT recipients was 3.05 Woods units (95% CI: 0.14-5.95). The overall mortality in the HLT group was 28% (95% CI: 18-41%) at an average follow-up of 15.68 months (95% CI: 0.82-30.54), and 35% (95% CI: 17-58%) in the HT group at an average follow-up of 37.26 months (95% CI: 6.68-67.84). Freedom from rejection in HT was 94% (95% CI: 75-99%) at 1 month, 77% (95% CI: 30-96%) at 6 months, and 41% (95% CI: 33-50%) at 1 year.

Conclusions

The domino procedure appears to be a viable option in properly selected patients that can be performed safely with acceptable outcomes.

Right atrial versus right ventricular HeartWare HVAD position in patients on biventricular HeartWare HVAD support: A systematic review

In patients with biventricular heart failure or refractory right heart failure following HeartWare HVAD placement, off-label placement of a right-sided HeartWare HVAD has been described both in the right ventricular (RV) and right atrial (RA) positions. We sought to evaluate and compare the outcomes of right-sided HeartWare HVAD using the RA versus RV approach. An electronic search was performed in the English literature to identify all reports of left- and right-heart support with HeartWare HVAD. Of the 1,288 articles identified, 13 articles with 56 cases met inclusion criteria. Patient-level data were extracted and analyzed. The median patient age was 52 years (IQR 33.0-59.0) and 40/50 (80.0%) were male. Overall, 21/56 patients (37.5%) had RA HVAD, while 35/56 (62.5%) had RV HVAD. Most underwent concomitant HVAD placement [RA: 17/21 (81.0%) vs. RV: 31/35 (88.6%), P = .69]. In those who did not, the median time between left and right HVAD was 10 days (IQR 7-14) for RA HVAD and 12 days (IQR 8-30) for RV HVAD (P = .77). The median time of support was 351 days (IQR 136-626) for RA HVAD compared to 135 days (IQR 61-244) for RV HVAD (P = .02). Pump thrombosis occurred at a similar rate [RA: 3/10 (30.0%) vs. RV: 6/20 (30.0%), P = 1], as did GI bleeding [RA: 10/35 (28.6%) vs. RV: 5/21 (23.8%), P = .94] during the follow-up time period. Kaplan-Meier analysis when censored for transplant showed higher survival with RA HVAD compared to RV HVAD (P = .036), with an estimated survival at 1 year of 91.7% (95% CI 77.3-100.0) in RA HVAD versus 66.2% (95% CI 48.9-89.6) for RV HVAD. RA HVAD appears to be a viable option for durable right-sided support with outcomes at least comparable to RV HVAD.

Ventricular arrhythmias following continuous-flow left ventricular assist device implantation: A systematic review

Ventricular arrhythmias (VA) are not uncommon after continuous-flow left ventricular assist device (CF-LVAD) implantation. In this systematic review, we sought to identify the patterns of VA that occurred following CF-LVAD implantation and evaluate their outcomes. An electronic search was performed to identify all articles reporting the development of VA following CF-LVAD implantation. VA was defined as any episode of ventricular fibrillation (VF) or sustained (>30 seconds) ventricular tachycardia (VT). Eleven studies were pooled for the analysis that included 393 CF-LVAD patients with VA. The mean patient age was 57 years [95%CI: 54; 61] and 82% [95%CI: 73; 88] were male. Overall, 37% [95%CI: 19; 60] of patients experienced a new onset VA after CF-LVAD implantation, while 60% [95%CI: 51; 69] of patients had a prior history of VA. Overall, 88% of patients [95%CI: 78; 94] were supported on HeartMate II CF-LVAD, 6% [95%CI: 3; 14] on HeartWare HVAD, and 6% [95%CI: 2; 13] on other CF-LVADs. VA was symptomatic in 47% [95%CI: 28; 68] of patients and in 50% [95%CI: 37; 52], early VA (<30 days from CF-LVAD) was observed. The 30-day mortality rate was 7% [95%CI: 5; 11]. Mean follow-up was 22.9 months [95%CI: 4.8; 40.8], during which 27% [95%CI: 17; 39] of patients underwent heart transplantation. In conclusion, approximately a third of patients had new VA following CF-LVAD placement. VA in CF-LVAD patients is often symptomatic, necessitates treatment, and carries a worse prognosis.

Comparison of SynCardia total artificial heart and HeartWare HVAD biventricular support for management of biventricular heart failure: a systematic review and meta-analysis

BACKGROUND

The aim of this study was to compare the outcomes of patients undergoing SynCardia total artificial heart (TAH) and biventricular HeartWare ventricular assist device (Bi-HVAD) support for biventricular heart failure (HF).

METHODS

Electronic search was performed to identify all relevant studies detailing patients who underwent biventricular assist device implantation using Bi-HVAD devices and those who underwent TAH placement for biventricular HF. Twelve studies including 512 patients in the TAH group versus 38 patients in the Bi-HVAD group were pooled for meta-analysis.

RESULTS

Ischemic cardiac etiology was present in 32% (95% CI, 24-47) of TAH vs. 15% (95% CI, 4-44) of Bi-HVAD patients (P=0.21). There was a comparable incidence of stroke [TAH 11% (95% CI, 7-16) vs. Bi-HVAD 13% (95% CI, 2-51), P=0.86] and acute kidney injury [TAH 28% (95% CI, 2-89) vs. Bi-HVAD 27% (95% CI, 9-59), P=0.98]. Overall infection rate was 67% (95% CI, 47-82) in TAH and 36% (95% CI, 10-74) in Bi-HVAD (P=0.16). Driveline infections were comparable between the two groups [TAH 11% (95% CI, 6-19) vs. Bi-HVAD 8% (95% CI, 1-39), P=0.73] and although a higher incidence of mediastinitis was found in the Bi-HVAD group [TAH 4% (95% CI, 2-7) vs. Bi-HVAD 15% (95% CI, 4-45), P=0.07] there was no statistically significant difference between the groups. Postoperative bleeding was present in 42% (95% CI, 28-58) of TAH vs. 23% (95% CI, 8-52) of Bi-HVAD (P=0.22). Patients in the TAH group had shorter duration of support [TAH 71 days (95% CI, 15-127) vs. Bi-HVAD 167 days (95% CI, 116-217), P=0.01]. At the mean follow-up time of 120 days, (95% CI, 83-157) patients in both groups had similar overall mortality [TAH 36% (95% CI, 22-49) vs. Bi-HVAD 26% (95% CI, 6-46), P=0.44] including mortality on device support [TAH 26% (95% CI, 17-36) vs. Bi-HVAD 21% (95% CI, 4-37), P=0.55]. Discharge home on support was achieved in 6% (95% CI, 4-17%) of TAH patients vs. 73% (95% CI, 48-89%) of Bi-HVAD (P<0.01), and 68% (95% CI, 52-84) of TAH patients were transplanted vs. 61% (95% CI, 47-75) in the Bi-HVAD group (P=0.14).

CONCLUSIONS

Patients on Bi-HVAD support were more likely to be able to be discharged home on support and had similar overall mortality to TAH, albeit with much longer duration of support.

Valvectomy versus replacement for the surgical treatment of infective tricuspid valve endocarditis: a systematic review and meta-analysis

BACKGROUND

Optimal surgical treatment of infective tricuspid valve endocarditis in patients with intravenous drug use (IVDU) remains controversial. Tricuspid valvectomy has been proposed for infective tricuspid valve endocarditis in this patient population given the inherent social concerns. The aim of this systematic review and meta-analysis was to compare outcomes of valvectomy versus replacement for the surgical treatment of isolated infective tricuspid valve endocarditis.

METHODS

An electronic search was performed to identify all relevant studies published. After assessment for inclusion and exclusion criteria, 16 original studies were pooled for systematic review and meta-analysis.

RESULTS

There were a total of 752 patients with infective tricuspid valve endocarditis, of which 14% underwent valvectomy and 86% underwent replacement (mean follow-up 4.2 years, 95% CI, 1.9-6.4 years). The most common indications for surgical intervention were septic pulmonary embolism in the valvectomy group (74%, 95% CI, 28-95%) and persistent sepsis in the replacement group (62%, 95% CI, 31-86%). There were no differences in rates of stroke [valvectomy 4% (95% CI, 1-11%) vs. replacement 3% (95% CI, 1-16%), P=0.85] but there was increased likelihood of prolonged ventilation in those who underwent valvectomy [valvectomy 40% (95% CI, 30-51%) vs. replacement 26% (95% CI, 23-30%), P<0.01]. There were no differences in 30-day post-operative mortality [valvectomy 13% (95% CI, 5-30%) vs. replacement 7% (95% CI, 5-10%), P=0.21], post-operative right heart failure [valvectomy 27% (95% CI, 10-53%) vs. replacement 11% (95% CI, 5-25%), P=0.17] and recurrent endocarditis [valvectomy 7% (95% CI, 2-23%) vs. replacement 19% (95% CI, 12-28%), P=0.81]. Valvectomy had a higher rate of tricuspid valve reoperation [valvectomy 56% (95% CI, 15-90%) vs. initial replacement 14% (95% CI, 7-27%), P=0.06].

CONCLUSIONS

Tricuspid valvectomy is an acceptable initial therapy for infective tricuspid valve endocarditis in patients with IVDU, providing a bridge to identify those who will self-select as candidates for staged valve replacement.

Heparin-induced thrombocytopenia during extracorporeal life support: incidence, management and outcomes

Background

Heparin-induced thrombocytopenia (HIT) is a severe antibody-mediated reaction leading to transient prothrombosis. However, its incidence in patients on extracorporeal life support (ECLS) is not well described. The aim of this systematic review was to report the incidence of HIT in patients on ECLS, as well as compare the characteristics and outcomes of HIT in patients undergoing veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and veno-venous ECMO (VV-ECMO).

Methods

An electronic search was performed to identify all studies in the English literature examining outcomes of patients with HIT on ECLS. All identified articles were systematically assessed using specific inclusion and exclusion criteria. Random effects meta-analysis as well as univariate analysis was performed.

Results

Of 309 patients from six retrospective studies undergoing ECLS, 83% were suspected, and 17% were confirmed to have HIT. Due to the sparsity of relevant retrospective data regarding patients with confirmed HIT on ECLS, patient-based data was subsequently collected on 28 patients from case reports and case series. Out of these 28 patients, 53.6% and 46.4% of them underwent VA-ECMO and VV-ECMO, respectively. Patients on VA-ECMO had a lower median platelet count nadir (VA-ECMO: 26.0 vs. VV-ECMO: 45.0 per µL, P=0.012) and were more likely to experience arterial thromboembolism (VA-ECMO: 53.3% vs. VV-ECMO: 0.0%, P=0.007), though there was a trend towards decreased likelihood of experiencing ECLS circuit oxygenator thromboembolism (VA-ECMO: 0.0% vs. VV-ECMO: 30.8%, P=0.075) and thromboembolism necessitating ECLS device or circuit exchange (VA-ECMO: 13.3% vs. VV-ECMO 53.8%, P=0.060). Kaplan-Meier survival plots including time from ECLS initiation reveal no significant differences in survival in patients supported on VA-ECMO as compared to VV-ECMO (P=0.300).

Conclusions

Patients who develop HIT on VA-ECMO are more likely to experience more severe thrombocytopenia and arterial thromboembolism than those on VV-ECMO. Further research in this area and development of standardized protocols for the monitoring, diagnosis and management of HIT in patients on ECLS support are warranted.

Graft patency after open versus endoscopic saphenous vein harvest in coronary artery bypass grafting surgery: a systematic review and meta-analysis

Background

Saphenous vein grafts (SVG) are a commonly used conduit for coronary artery bypass graft (CABG) surgery and can be harvested by either an open or endoscopic technique. Our goal was to evaluate long-term angiographic and clinical outcomes of open compared to endoscopic SVG harvest for CABG.

Methods

Electronic search was performed to identify all studies in the English literature that compared open and endoscopic SVG harvesting for CABG with at least one year of follow-up. The primary outcome was graft patency. Secondary outcomes included perioperative morbidity and mortality.

Results

Of 3,255 articles identified, a total of 11 studies were included for analysis. Of 18,131 patients, 10,873 (60%) patients underwent open SVG harvest and 7,258 (40%) patients underwent endoscopic SVG harvest. The mean age of patients was 65 years and 87% were male. The overall mean follow-up period was 2.6 years. During follow-up, patients who underwent open SVG harvest had superior graft patency per graft [open 82.3% vs. endoscopic 75.1%; OR: 0.61 (95% CI, 0.43-0.87); P=0.01], but higher rates of overall wound complications in the immediate post-operative period [open 3.3% vs. endoscopic 1.1%; OR: 0.02 (95% CI, 0.01-0.06); P<0.001]. Patients who underwent open SVG harvest had higher postoperative 30-day mortality [open 3.4% vs. endoscopic 2.1%; OR: 0.59 (95% CI, 0.37-0.94); P=0.03], but no significant difference in overall mortality [open 4.9% vs. endoscopic 4.9%; OR: 0.34 (95% CI, 0.50-1.27); P=0.34].

Conclusions

Patients who underwent an open SVG harvest technique had improved graft patency and comparable overall mortality to endoscopic SVG harvest at average follow-up time of 2.6 years. Patients with open SVG harvest had higher rates of early wound complications and postoperative 30-day mortality, however, there was no difference in overall mortality.

Percutaneous coronary intervention versus coronary artery bypass grafting in heart transplant recipients with coronary allograft vasculopathy: a systematic review and meta-analysis of 1,520 patients

Background

Transplant coronary artery vasculopathy (TCAV) is the major cause of late allograft failure and death in heart transplant recipients. The aim of this systematic review was to examine the outcomes of percutaneous coronary interventions (PCIs) as compared to coronary artery bypass grafting (CABG) surgery in the management of TCAV. Our secondary objective was to compare the use and outcomes of drug eluting stents (DES) as compared to bare metal stents (BMS) in this patient population.

Methods

Electronic search was performed to identify all studies in the English literature examining PCI as compared to CABG for TCAV in heart transplant recipients. All identified articles were systematically assessed for inclusion and exclusion criteria.

Results

Of the 4,989 studies identified, 29 studies were included. Among 1,520 patients who developed TCAV, 1,470 patients underwent PCI and 50 patients underwent CABG. There were no significant differences in baseline demographics and comorbidities among the PCI and CABG cohorts. Compared to the PCI cohort, patients who underwent CABG had a higher early mortality (CABG 36.4% vs. PCI 4.3%, P<0.001) and overall mortality (CABG 42.3% vs. PCI 21.4%, P=0.049). When comparing DES versus BMS cohorts, there were no significant differences in the rate of in-stent stenosis (DES 14.5% vs. BMS 24.4%, P=0.476), overall mortality (DES 17.4% vs. BMS 30.8%, P=0.302) or cardiac related mortality (DES 7.7% vs. BMS 21.8%, P=0.415).

Conclusions

CABG and PCI are both feasible modalities for revascularization in patients with TCAV where PCI is associated with lower mortality. There were no differences in outcomes among patients who underwent PCI with DES as compared to BMS. Potential bias may exist due to heterogeneity in available data. Further studies are needed to delineate evidence-based guidelines to tailor the appropriate therapy, CABG or PCI, to the appropriate patient.

Outcomes and survival following heart retransplantation for cardiac allograft failure: a systematic review and meta-analysis

Background

Long-term efficacy of heart retransplantation (RTx) for end-stage cardiac allograft failure remains unclear given the limited worldwide experience and is an important question to elucidate given the shortage of donor organs. The aim of this systematic review was to examine the outcomes of RTx in patients with cardiac allograft failure.

Methods

Electronic search was performed to identify all studies in the English literature assessing RTx for cardiac allograft failure. All identified articles were systematically assessed for inclusion and exclusion criteria.

Results

Eleven studies were included for analysis, with a total of 7,791 patients. A total of 7,446 patients underwent primary heart transplantation (HTx) whereas 345 patients underwent RTx with average time from primary HTx to RTx interval of 5.03 years (95% CI: 3.13-6.94 years). There were 35.2% of patients received RTx within 30 days of primary transplant. Early mortality was significantly higher among RTx patients (RTx 28.2% vs. HTx 11.2%, P<0.001) whereas survival was significantly higher among HTx patients when compared to RTx patients at 1 year (HTx 81.8% vs. RTx 59.1%, P<0.001), 2 years (HTx 77.9% vs. RTx 53.6%, P<0.001), 3 years (HTx 76.1% vs. RTx 49.8%, P<0.001), 5 years (HTx 68.8% vs. RTx 41.4%, P<0.001) and 10 years (HTx 53.9% vs. RTx 31.7%, P<0.001). There were no significant differences between HTx and RTx in terms of freedom from rejection at 1 year (HTx 61.0% vs. RTx 53.7%, P=0.43), 2 years (HTx 63.8% vs. RTx 53.7%, P=0.26), 3 years (HTx 62.9% vs. RTx 51.9%, P=0.30) and 5 years (HTx 61.0% vs. RTx 51.9%, P=0.36).

Conclusions

Patients who underwent heart RTx had a significant lower survival when compared to those who only underwent primary HTx. There were no significant differences in post-transplantation freedom from rejection. Careful patient selection and perioperative care can make heart RTx a viable option for selected recipients.

Predictors and clinical relevance of ventricular tachyarrhythmias in ambulatory patients with a continuous flow left ventricular assist device

BACKGROUND

Patients with a left ventricular assist device (LVAD) are at high risk for ventricular tachyarrhythmias (VTAs).

OBJECTIVE

We aimed to identify clinical predictors of VTAs and subsequent outcomes after VTA in ambulatory LVAD patients.

METHODS

A retrospective study of 149 patients with a continuous flow HeartMate II LVAD who survived to discharge from index hospitalization after LVAD implantation was performed from January 10, 2005, to September 3, 2013. A multivariate Cox model was used to assess clinical predictors of VTAs.

RESULTS

During a mean follow-up period of 2.1 ± 1.2 years, 41 patients (28%) experienced VTAs; 30 of these patients (71%) had ventricular tachycardia, and 11 (29%) had ventricular fibrillation. History of VTAs before LVAD (hazard ratio [HR] 3.06; 95% confidence interval [CI] 1.57-5.96; P = .001) and history of atrial fibrillation (AF) (HR 3.13; 95% CI 1.60-6.11; P = .008) were the most powerful predictors of VTAs after LVAD implantation. There were 19 deaths (46%) among patients with VTAs and 15 deaths (14%) among patients without VTAs (P < .001). In multivariate analysis, time-dependent VTAs after LVAD implantation were associated with a significantly higher risk of all-cause mortality when compared with those without VTAs (HR 7.28; 95% CI 3.50-15.15; P < .001).

CONCLUSION

In ambulatory LVAD patients, history of VTAs before LVAD implantation and history of AF predict VTAs after LVAD implantation. VTAs are associated with an increased risk of mortality. In such patients, aggressive measures to control VTAs and AF should be considered.

Evolving strategies in the treatment of acute myocardial infarction-induced cardiogenic shock

Despite advances in medical technology and re-vascularization interventions, the mortality rate for cardiogenic shock (CS) following acute myocardial infarction has remained at 50%. The majority of these mortalities are from left ventricular failure resulting in multi-system organ dysfunction. The field of mechanical circulatory support (MCS) has evolved within the past decade, with improved outcomes from extracorporeal membrane oxygenation as well as continuous-flow left ventricular assist devices (CF LVADs). In this paper, we discuss our institutional treatment strategies, the rationale for the protocol development, and our improved outcomes when using MCS in patients with refractory CS following acute myocardial infarction.

Evaluation and treatment of pump thrombosis and hemolysis

Ventricular assist devices (VADs) are not fully biocompatible, and are therefore predisposed to device thrombosis and subsequent pump dysfunction. Clinically significant hemolysis in VADs most often occurs as a result of device thrombosis, but can also be caused by other factors. Herein we describe the evaluation and management of VAD thrombosis and hemolysis.