Comparative Outcomes of Surgical and Transcatheter Aortic Valve Replacement: A Meta-analysis and Parametric Extrapolation of Clinical Trials.

INTRODUCTION: We aimed to pool randomized clinical trials (RCTs) comparing surgical aortic valve replacement (SAVR) with transcatheter aortic valve replacement (TAVR) and extrapolate pooled time-to-event data to compare long-term outcomes. METHODS: An electronic database search was performed for RCTs comparing SAVR with TAVR. The most current longest follow-up data for each RCT were included. Data were pooled using a random-effects model. Survival data were pooled for Kaplan-Meier analysis as well as parametric modeling with extrapolation. RESULTS: Seven RCTs comprising 7774 patients were included. Mean valve gradient at 5 y was comparable between SAVR [11 mmHg (3.7; 18.3)] and TAVR [8.1 mmHg (1.9; 14.3)] (P = 0.38). TAVR had a higher mean valve area at 30 d, 1 y, and 2 y [1.68 cm2 (1.22; 2.13) versus 1.8 cm2 (1.35; 2.25), P = 0.02]. SAVR had a higher freedom from any paravalvular leak at 30 d and 1 y [86% (81; 90) versus 39% (36; 41), P < 0.01]. All-cause death was lower in the SAVR group at 5 y [39% (29; 50) versus 43% (31; 57), P < 0.01]. Although no differences were seen between SAVR and TAVR in the pooled Kaplan-Meier analysis of all-cause mortality and composite of all-cause mortality or stroke, parametric modeling with extrapolation showed significant divergence for both outcomes. CONCLUSIONS: Pooled all-cause mortality as well as pooled composite of all-cause mortality or stroke indicated better survival with SAVR at 5 y. Long-term parametric extrapolation also indicated superior survival with SAVR.

Outcomes of outflow graft stenting in HeartMate 3 left ventricular assist devices: A systematic review and individual patient data meta-analysis.

PURPOSE: LVAD outflow graft stenosis continues to remain prevalent with a high complication rate. We sought to pool the existing evidence on indications, utilization patterns, and outcomes of transcatheter interventions for outflow graft stenosis in the HeartMate 3 LVAD. METHODS: An electronic search was performed to identify all studies in the English literature reporting on HeartMate 3 LVAD outflow graft stenting. Patient-level data were extracted for analysis. RESULTS: Thirteen published reports and one unpublished case comprising a total of 28 patients were included. Median patient age was 68.5 years [Interquartile range: 58, 71] and 25.9% (7/27) were female. Dyspnea [60.7% (17/28)] was the most common presenting symptom. Low flow alarms were present in 60% (15/25) of patients. Findings included external compression [35.7% (10/28)], graft twist [21.4% (6/28)], graft twist and external compression [14.3% (4.28)], intraluminal thrombus [10.7% (3/28)], graft twist and intraluminal thrombus [3.6% (1/28)], and pseudoaneurysm of outflow graft [3.6% (1/28)]. Median time from LVAD implantation to stenting was 2.1 years [1.4, 3]. Immediate flow normalization after stenting was observed in 85.7% (24/28). The 30-day mortality was 12% (3/25). Overall mortality was 12% (3/25) at a median follow-up of 3.9 months [1, 17]. CONCLUSION: Outflow graft stenting in the HeartMate 3 LVAD appears to be a reasonable treatment option for outflow graft stenosis, with low overall rates of complications and mortality. Further refinement of indications and approaches may improve outcomes.

Peri-operative fever and LVAD: SIRS or impaired right ventricular strain?

BACKGROUND: An inflammatory milieu after left ventricular assist device (LVAD) implantation is associated with multi-organ dysfunction and pre-operative heightened inflammatory state is associated with right ventricular failure after LVAD implantation. METHODS: We performed a retrospective analysis of 30 LVAD patients in our institution within the last 2 years for the development of fever and compared them to 30 non-LVAD open-heart surgery patients. RESULTS: Our results suggest that patients undergoing LVAD implantation are more likely to develop fever in the immediate post-operative period compared to other open-heart surgeries. This is independent of pharmacological treatment, age, or ethnical background. Females and obese patients were more likely to develop fever. CONCLUSION: Patients with right ventricular dysfunction, as demonstrated by elevated central venous pressure (CVP), had the strongest correlation with fever development. These results pose the question if there is a systemic inflammatory response-like phenomenon driven by increased right ventricular dysfunction.

Predicted heart mass based on ideal body weight for donor-to-recipient size matching.

BACKGROUND: Predicted heart mass (PHM) is a commonly used tool for donor-to-recipient size matching. However, incorporating body weight as part of PHM can be considered problematic given its high variability, and low metabolic nature of fat. We sought to assess whether substituting the actual donor and recipient weight with the ideal body weight (IBW) would affect the association of donor-to-recipient PHM ratio with 1-year and overall survival after heart transplantation. METHODS: The United Network for Organ Sharing (UNOS) database was queried for adult patients who received a primary heart transplant between January 2000 and September 2021. RESULTS: Both PHM and ideal PHM (IPHM) ratios were associated with one-year (PHM: p = .003; IPHM: p = .0007) and overall (PHM: p = .02; IPHM: p = .02) survival. In the continuous analysis with restricted cubic splines, both PHM (p = .0003) and IPHM (p = .00001) were associated with relative hazards of death. CONCLUSION: IPHM is significantly associated with post-transplant survival and may be a useful compliment to PHM.

Microaxial circulatory support for percutaneous coronary intervention: A systematic review and meta-analysis.

BACKGROUND: Microaxial circulatory support devices have been used to support patients treated with percutaneous coronary intervention (PCI) for acute myocardial infarction complicated by cardiogenic shock (AMICS). The purpose of this systematic review and meta-analysis was to pool and analyze the existing evidence on the baseline characteristics, periprocedural data, and outcomes of microaxial support before and after PCI in AMICS. METHODS: An electronic database search was performed to identify all cohort studies on Impella and PCI for cardiogenic shock in the English language. A total of five articles comprising 543 patients were included. These patients received microaxial support either before (pre-PCI) or after (post-PCI) undergoing PCI. Comparative analyses were done between both groups. RESULTS: The mean patient age was 66 years [95% Confidence Interval (58-74)], and 22% (89/396) of patients were female. ST-elevation myocardial infarctions (MI) comprised 64% (44-80) of MIs and 50% (44-56) of MIs involved the left anterior descending artery. The mean number of diseased vessels was 2.21 (1.62-2.80). The mean left ventricular ejection fraction was 31% (23.4-38.6). The mean arterial pressure was 66.3 mm Hg (54.1-78.5). Mean serum lactate [6.1 mmol/L (3.3-8.9)] and serum creatinine [1.4 mg/dl (1.0-1.7)] were similar between groups. 30-day mortality was lower in the pre-PCI group [41% (34%-49%)] compared to the post-PCI group [61% (42%-77%), p < 0.01]. Pooled Kaplan-Meier analysis showed better early survival in the pre-PCI group (p < 0.001). CONCLUSION: Patients presenting with AMICS were similar at baseline in both pre-PCI and post-PCI groups. Nevertheless, pre-PCI group showed better early survival compared to post-PCI group.

Utility of Recipient Cardiothoracic Ratio in Predicting Delayed Chest Closure after Heart Transplantation.

BACKGROUND: Predicted cardiac mass (PCM) has been well validated for size matching donor hearts to heart transplantation recipients. We hypothesized that cardiothoracic ratio (CTR) could be reflective of recipient-specific limits of oversizing, and sought to determine the utility of donor to recipient PCM ratio (PCMR) and CTR in predicting delayed chest closure after heart transplantation. METHODS: A retrospective review of prospectively collected data on 38 consecutive heart transplantations performed at our institution from 2017 to 2020 was performed. Donor and recipient PCM were estimated using Multi-Ethnic Study of Atherosclerosis predictive models. Receiver operating characteristic analysis was performed to determine the discriminatory power of the ratio of PCMR to CTR in predicting delayed sternal closure. RESULTS: Of the 38 patients, 71.1% (27/38) were male and the median age at transplantation was 58 (interquartile range [IQR]: 47-62) years. Ischemic cardiomyopathy was present in 31.6% of recipients (12/38). Median recipient CTR was 0.63 [IQR: 0.59-0.66]. Median donor to recipient PCMR was 1.07 [IQR: 0.96-1.19], which indicated 7% oversizing. Thirteen out of 38 (34.2%) underwent delayed sternal closure. Primary graft dysfunction occurred in 15.8% (6/38). PCMR/CTR showed good discriminatory power in predicting delayed sternal closure [area under the curve: 80.4% (65.3-95.6%)]. PCMR/CTR cut-off of 1.7 offered the best trade-off between the sensitivity (69.6%) and specificity (91.7%). CONCLUSION: CTR could be helpful in guiding the recipient-specific extent of oversizing donor hearts. Maintaining the ratio of PCMR to CTR below 1.7 could avoid excessive oversizing of the donor heart.

Association of Heart Transplant Volume with Presence of Lung Transplant Programs and Heart Transplant's SRTR One-year Survival Rating.

BACKGROUND: Several factors affect heart transplant (HTx) and lung transplant (LTx) program outcomes. Variabilities in institutional and community characteristics have been shown to influence survival. At present, half of HTx centers in the United States do not possess a concomitant LTx program. This study sought to better understand the characteristics of HTx with and without LTx programs. METHODS: Nationwide transplant data were collected from the Scientific Registry of Transplant Recipients (SRTR) in August 2020. SRTR star rating ranges from tier 1 (lowest) to tier 5 (highest). HTx volumes and SRTR star ratings for survival were compared between the centers with heart-only (H0) programs and the centers with heart-lung (HL) programs. RESULTS: SRTR star ratings were available for 117 transplant centers with one or more HTx reported. The median number of HTx performed over 1 year was 16 (interquartile range [IQR]: 2-29). The number of HL centers (n = 67, 57.3%) were comparable to H0 centers (n = 50, 42.7%; p = 0.14). The HTx volume at the HL centers (28 [IQR: 17-41]) exceeded the HTx volume at the H0 centers (13 [IQR: 9-23]; p < 0.01), but were comparable to the LTx volume at the HL centers (31 [IQR: 16-46]; p = 0.25). The median HTx one-year survival rating was 3 (IQR: 2-4) at both the H0 and HL centers (p = 0.85). The HTx and LTx volumes were positively associated with the respective 1-year survivals (p < 0.01). CONCLUSION: While the presence of an LTx program is not directly associated with HTx survival, it has a positive association with the HTx volume. The HTx and LTx volumes are positively associated with the 1-year survival.

Assessing donor-recipient size metrics for heart transplant outcomes: UNOS database analysis.

STUDY: There is no widely accepted donor to recipient size-match metric to predict outcomes in cardiac transplant. The predictive ability of size-match metrics has not been studied when recipients are stratified by heart failure etiology. We sought to assess the performance of commonly used size metrics to predict survival after heart transplant, accounting for restrictive versus non-restrictive pathology. METHODS: The UNOS registry was queried from 2000 to 2017 for all primary isolated heart transplants. Donor-recipient ratios were calculated for commonly used size metrics and their association with survival was assessed using continuous, nonlinear analysis. RESULTS: 29 817 patients were identified. Height (P < .001), predicted heart mass (PHM) (P = .003), ideal body weight (IBW) (P < .001) and body mass index (BMI) (P = .003) ratios were significantly associated with survival, while weight and body surface area (BSA) ratios were not. When stratified, only BMI ratio retained significance for both restrictive (P = .051) and non-restrictive (P = .003) subsets. Recipients with restrictive etiology had increased risk of mortality with both a lower and higher BMI ratio. CONCLUSIONS: While many metrics show association with survival in the non-restrictive subset, BMI is the only metric that retains significance in the restrictive subset. Recipients with restrictive and non-restrictive etiologies of heart failure tolerate size mismatch differently.

Mechanical and interventional support for heart failure with preserved ejection fraction: A review.

INTRODUCTION: Restrictive cardiomyopathy (RCM) and hypertrophic cardiomyopathy (HCM) are two disease processes that are known to progress to heart failure with preserved ejection fraction (HFpEF). Pharmacologic therapies for HFpEF have not improved patient outcomes or reduced mortality in this patient cohort; thus, there continues to be substantial interest in other treatment strategies, including surgical interventions and devices. In this article, we explore and report the current utility of percutaneous therapies and surgically implanted mechanical support in the treatment of patients with HFpEF. RESULTS: Treatment strategies include percutaneous interventions with interatrial shunts, left atrial assist devices (LAADs), and ventricular assist devices (VADs) in various configurations. Although VADs have been employed to treat patients with heart failure with reduced ejection fraction, their efficacy is limited in those with RCM and HCM. A left atrial-to-aortic VAD has been proposed to directly unload the left atrium, but data is limited. Alternatively, a LAAD could be placed in the mitral position and simultaneously unload the left atrium, while filling the left ventricle. CONCLUSION: A left atrial assist device in the mitral position is a promising solution to address the hemodynamic abnormalities in RCM and HCM; these pumps, however, are still under development.

Extracorporeal life support and cardiopulmonary bypass for central airway surgery: A systematic review.

BACKGROUND: Major airway surgery can pose a complex problem to perioperative central airway management. Adjuncts to advanced ventilation strategies have included cardiopulmonary bypass, veno-arterial, or veno-venous extracorporeal life support. We performed a systematic review to assess the existing evidence utilizing these strategies. METHODS: An electronic search was conducted to identify studies written in English reporting the use of extracorporeal life support (ECLS) during central airway surgery. Thirty-six articles consisting of 78 patients were selected and patient-level data were analyzed. RESULTS: Median patient age was 47 [IQR: 34-53] and 59.0% (46/78) were male. Indications for surgery included central airway or mediastinal cancer in 57.7% (45/78), lesion or injury in 15.4% (12/78), and stenosis in 12.8% (10/78). Support was initiated pre-operatively in 9.9% (7/71) and at the time of induction in 55.3% (42/76). It was most commonly used at the time of tracheal resection/repair [93.2% (68/73)], intubation of the tracheal stump [94.4% (68/72)], and re-anastomosis [94.2% (65/69)]; 13.7% (10/73) patients were supported post-operatively. The most commonly performed surgery was tracheal repair or resection in 70.3% (52/74). Median hospital stay was 12 [8, 25] days and in-hospital mortality was 7.9% (6/76). There was no significant difference in survival between the three groups (p = .54). CONCLUSIONS: Extracorporeal membrane oxygenation offers versatility in timing, surgical approach, and ECLS runtime that makes it a viable addition to the surgical armamentarium for treating complex central airway pathologies.

Utilization and outcomes of extracorporeal CO2 removal (ECCO2 R): Systematic review and meta-analysis of arterio-venous and veno-venous ECCO2 R approaches.

INTRODUCTION: Extracorporeal carbon dioxide removal (ECCO2 R) provides respiratory support to patients suffering from hypercapnic respiratory failure by utilizing an extracorporeal shunt and gas exchange membrane to remove CO2 from either the venous (VV-ECCO2 R) or arterial (AV-ECCO2 R) system before return into the venous site. AV-ECCO2 R relies on the patient's native cardiac function to generate pressures needed to deliver blood through the extracorporeal circuit. VV-ECCO2 R utilizes a mechanical pump and can be used to treat patients with inadequate native cardiac function. We sought to evaluate the existing evidence comparing the subgroups of patients supported on VV and AV-ECCO2 R devices. METHODS: A literature search was performed to identify all relevant studies published between 2000 and 2019. Demographic information, medical indications, perioperative variables, and clinical outcomes were extracted for systematic review and meta-analysis. RESULTS: Twenty-five studies including 826 patients were reviewed. 60% of patients (497/826) were supported on VV-ECCO2 R. The most frequent indications were acute respiratory distress syndrome (ARDS) [69%, (95%CI: 53%-82%)] and chronic obstructive pulmonary disease (COPD) [49%, (95%CI: 37%-60%)]. ICU length of stay was significantly shorter in patients supported on VV-ECCO2 R compared to AV-ECCO2 R [15 (95%CI: 7-23) vs. 42 (95%CI: 17-67) days, p = 0.05]. In-hospital mortality was not significantly different [27% (95%CI: 18%-38%) vs. 36% (95%CI: 24%-51%), p = 0.26]. CONCLUSION: Both VV and AV-ECCO2 R provided clinically meaningful CO2 removal with comparable mortality.

The impact of peripheral arterial disease on left ventricular assist device implantation: A propensity-matched analysis of the nationwide inpatient sample database.

Left ventricular assist device (LVAD) candidacy screening includes evaluation for peripheral arterial disease (PAD). However, given current evidence, the impact of PAD on post-LVAD complications remains unknown. The National Inpatient Sample (NIS) database (2002-2017) was utilized to identify all LVAD cases. The in-hospital safety endpoints included major cardiovascular adverse events and its components. A propensity-matched analysis was used to obtain adjusted odds ratios (aOR). A subgroup analysis of patients with diabetes mellitus (DM) with PAD was also performed. A total of 27 424 patients with LVAD implantation (PAD: 516 [1.8%] and no-PAD 26 908 [98.2%]) were included. There were significant intergroup differences in the demographics and baseline comorbidities. A weighted sample of 1053 (no-PAD 537, PAD 516) propensity-matched population was selected. The adjusted odds for in-hospital mortality (aOR 1.7; 95% CI, 1.2-2.44, P = .004) were found to be significantly higher for LVAD-patients with PAD. There was no significant difference in the adjusted odds of MACE (aOR 1.16, 95% CI 0.87-1.5), postprocedure bleeding (aOR 0.88, 95% CI 0.62-1.26, P = .54) and risk of pneumonia (aOR 0.67, 95% CI 0.44-1.15, P = .63) between the two groups. A selected cohort of DM-only population (7339) consistently showed a higher adjusted mortality rate in PAD patients with LVAD implantation (aOR 2.3, 95% CI 1.2-4.47, P = .01). The rate of MACE (P = .17), myocardial infarction (P = .12), stroke (P = .60), postprocedural (0.10), and major bleeding (P = .51) remained identical between patients with PAD and those with no-PAD. PAD confers an increased risk of in-hospital all-cause mortality in patients undergoing LVAD implantation. This risk increases further in patients with a concomitant diagnosis of DM.

Continuous-flow LVAD exchange to a different pump model: Systematic review and meta-analysis of the outcomes.

Despite improved outcomes of modern continuous-flow left ventricular assist devices (CF-LVADs), device exchange is still needed for various indications. While the majority of CF-LVADs are exchanged to the same model, exchange to a different pump model is occasionally warranted. In this meta-analysis, we sought to consolidate the existing evidence to better elucidate the indications and outcomes in these cases. A comprehensive systematic search of adult patient cohorts who underwent CF-LVAD exchange to a different CF-LVAD model was performed. Study-level data from 10 studies comprising 98 patients were extracted and pooled for analysis. Mean patient age was 58 (95% CI: 48-65) and 81% were male. Indication for initial CF-LVAD was ischemic cardiomyopathy in 45% (34-57). Initial device was HeartMate II LVAD (HMII) in 93 (94.9%) and HeartWare HVAD (HW) in 5 (5.1%) patients. After mean CF-LVAD support time of 18.8 (15.2-22.4) months, exchange indications included thrombosis in 71% (43-89), infection in 21% (8-47) and device malfunction in 12% (7-21). HMII to HW exchange occurred in 53 (54.1%) patients, HMII to HeartMate III (HM3) in 32 (32.7%), and HM II to either HW or HM3 in 13 (13.2%) patients. Postoperatively, right ventricular assist device was required in 16% (8-32). Overall, 20% (8-40) of patients experienced a stroke, while HW patients had a significantly higher stroke incidence than HM3 patients (HW: 21% (8-47) vs. HM3: 5% (1-24), P < .01). Overall 30-day mortality was 10% (6-17), while HW had a significantly worse 30-day mortality than HM3 (HW: 13% (7-24) vs. HM3: 5% (1-24), P = .03). Following device exchange from a different CF-LVAD model, HM3 is associated with lower stroke and higher survival when compared to HW.

Clinical implications of LDH isoenzymes in hemolysis and continuous-flow left ventricular assist device-induced thrombosis.

Pump-induced thrombosis continues to be a major complication of continuous-flow left ventricular assist devices (CF-LVADs), which increases the risks of thromboembolic stroke, peripheral thromboembolism, reduced pump flow, pump failure, cardiogenic shock, and death. This is confounded by the fact that there is currently no direct measure for a proper diagnosis during pump support. Given the severity of this complication and its required treatment, the ability to accurately differentiate CF-LVAD pump thrombosis from other complications is vital. Hemolysis measured by elevated lactate dehydrogenase (LDH) enzyme levels, when there is clinical suspicion of pump-induced thrombosis, is currently accepted as an important metric used by clinicians for diagnosis; however, LDH is a relatively nonspecific finding. LDH exists as five isoenzymes in the body, each with a unique tissue distribution. CF-LVAD pump thrombosis has been associated with elevated serum LDH-1 and LDH-2, as well as decreased LDH-4 and LDH-5. Herein, we review the various isoenzymes of LDH and their utility in differentiating hemolysis seen in CF-LVAD pump thrombosis from other physiologic and pathologic conditions as reported in the literature.

Single versus multi-drug antimicrobial surgical infection prophylaxis for left ventricular assist devices: A systematic review and meta-analysis.

Infection remains the Achilles heel of left ventricular assist device (LVAD) therapy. However, an optimal antimicrobial surgical infection prophylaxis (SIP) regimen has not been established. This study evaluated the efficacy of a single-drug SIP compared to a multi-drug SIP on clinical outcomes in patients undergoing continuous-flow LVAD (CF-LVAD) and pulsatile LVAD (P-LVAD) implantation. An electronic search was performed to identify studies in the English literature on SIP regimens in patients undergoing LVAD implantation. Identified articles were assessed for inclusion and exclusion criteria. Fourteen articles with 1,311 (CF-LVAD: 888; P-LVAD: 423) patients were analyzed. Overall, 501 (38.0%) patients received single-drug SIP, whereas 810 (62.0%) received multi-drug SIP. Time to infection was comparable between groups. There was no significant difference in overall incidence of LVAD-specific infections [single-drug: 18.7% vs. multi-drug: 24.8%, P = 0.49] including driveline infections [single-drug: 14.1% vs. multi-drug: 20.8%, P = 0.37]. Compared to single-drug SIP, patients who received multi-drug SIP had a significantly lower survival rate [single-drug: 90.0% vs. multi-drug: 76.0%, P = 0.01] and infection-free survival rate [single-drug: 88.4% vs. multi-drug: 77.3%, P = 0.04] at 90 days. However, there were no significant differences in 1-year survival and 1-year infection-free survival between groups. No survival differences were observed in the CF-LVAD subset as well. This study demonstrated no additional advantage of a multi-drug compared to a single-drug regimen for SIP. Although there was a modest advantage in early survival among CF-LVAD and P-LVAD patients who received single-drug SIP, there were no significant differences in the 1-year survival and 1-year infection-free survival.

Implementation of a Standardized Transfusion Protocol for Cardiac Patients Treated With Venoarterial Extracorporeal Membrane Oxygenation Is Associated With Decreased Blood Component Utilization and May Improve Clinical Outcome.

BACKGROUND: Extracorporeal membrane oxygenation supplies oxygenated blood to the body supporting the heart and lungs. Survival rates of 20% to 50% are reported among patients receiving ECMO for cardiac arrest, severe cardiogenic shock, or failure to wean from cardiopulmonary bypass following cardiac surgery. Bleeding is one of the most common complications in ECMO patients due to coagulopathy, systemic anticoagulation, and the presence of large bore cannulas at systemic pressure. Absence of a standardized transfusion protocol in this population leads to inconsistent transfusion practices. Here, we assess a newly developed dedicated transfusion protocol in this clinical setting. METHODS: Data were retrospectively reviewed for the first 30 consecutive cardiac ECMO patients prior and post implementation of the ECMO transfusion protocol. Diagnoses, laboratory results, blood component utilization, and outcomes were collected and analyzed. RESULTS: Comorbidities were similar between the 2 eras, as well as the pre-ECMO ejection fraction (P = .568) and duration on ECMO (P = .278). Transfusion utilization data revealed statistically significant decreases in almost all blood components and a savings in blood component acquisition costs of 51% ($175, 970). In addition, an almost 2-fold increase in survival rate was observed in the post-ECMO transfusion protocol era (63% vs 33%; relative risk = 1.82; 95% confidence interval, 1.07-3.10; P = .028). CONCLUSIONS: Our data indicate that implementation of a standardized transfusion protocol, using more restrictive transfusion indications in cardiac ECMO patients, was associated with reduced blood product utilization, decreased complications, and improved survival. This multidepartmental approach facilitates better communication and adherence to consensus clinical decision making between intensive care unit, surgery, and transfusion service and optimizes care of complicated and acutely ill patients.

Cannulation-Related Complications on Veno-Arterial Extracorporeal Membrane Oxygenation: Prevalence and Effect on Mortality.

Cannulation-related complications are a known source of morbidity in patients supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite its prevalence, little is known regarding the outcomes of patients who suffer such complications. This is a single institution review of cannulation-related complications and its effect on mortality in patients supported on VA-ECMO from January 2010-2015 using three cannulation strategies: axillary, femoral, and central. Complications were defined as advanced if they required major interventions (fasciotomy, amputation, site conversion). Patients were divided into two groups (complication present vs. not present) and Kaplan-Meier analysis was performed to determine any differences in their survival distributions. There were 103 patients supported on VA-ECMO: 41 (40%), 36 (35%), and 26 (25%) were cannulated via axillary, femoral, and central access, respectively. Cannulation-related complications occurred in 33 (32%) patients and this did not differ significantly between either axillary (34%), femoral (36%), or central (23%) strategies (P = 0.52). The most common complications encountered were hemorrhage and limb ischemia in 19 (18%) and 11 (11%) patients. Hemorrhagic complications did not differ between groups (P = 0.37), while limb ischemia and hyperperfusion were significantly associated with femoral and axillary cannulation, at a rate of 25% (P < 0.01) and 15% (P = 0.01), respectively. There was no difference in the incidence of advanced complications between cannulation groups: axillary (12%) vs. femoral (14%) vs. central (8%; P = 0.75). In addition, no increase in mortality was noted in patients who developed a cannulation-related complication by Kaplan-Meier estimates (P = 0.37). Cannulation-related complications affect a significant proportion of patients supported on VA-ECMO but do not differ in incidence between different cannulation strategies and do not affect patient mortality. Improved efforts at preventing these complications need to be developed to avoid the additional morbidity in an already critical patient population.

Single-Center Experience With HeartMate II Left Ventricular Assist Device Explantation.

In patients with continuous flow left ventricular assist devices (CF-LVADs) myocardial recovery is uncommon. Given the heterogeneity of the population implanted and low incidence of recovery, the discovery of native left ventricular (LV) recovery and criteria for explantation of CF-LVAD system is not clearly determined. We sought to analyze the characteristics of the patients who underwent CF-LVAD explantation at our institution. Prospectively collected data on patients supported with CF-LVADs were reviewed retrospectively. Patients who underwent CF-LVAD explants were identified and their characteristics were analyzed with a focus on patient presentation and determinants of explantability. From November 2006 to June 2014, 223 patients (181 male, 42 female) underwent implantation of HeartMate II LVAD. Seven female (16.7%) and one male (0.6%) patients were explanted (P < 0.001). Mean age was 43 ± 9 years and etiology for cardiomyopathy was ischemic in three (37.5%) patients, nonischemic in four (50%) patients, and mixed in the one (12.5%) male patient of the cohort. Five (62.5%) patients presented acutely with significant hemolysis, and were found to have LV improvement as well as reduced, absent, or reversed diastolic flow velocities on echocardiography. Overall, mean lactate dehydrogenase level before explantation was 1709 ± 1168 U/L compared to the mean baseline level of 601 ± 316 U/L (P = 0.048). Mean LV ejection fraction (LVEF) improved from 17 ± 7% preimplant to 56 ± 11% pre-explantation (P < 0.001). Median number of days on CF-LVAD support was 870 (interquartile range, 209-975) while mean duration of follow-up after the CF-LVAD explantation was 276 ± 240 days. Mean LVEF dropped from 46 ± 19% postexplantation to 34 ± 10% during the most recent follow-up (P = 0.015). At our institution, patients who underwent LVAD explants were predominantly women with nonischemic cardiomyopathy. Clinical evidence of hemolysis and echocardiographic evidence of reduced or absent diastolic flow velocities were common findings in these patients. Over time, patient's native LV function declined in the absence of LVAD (after LVAD explantation). Significant challenges remain in predicting LV recovery and identifying those individuals who have recovered myocardial function significant enough to be explanted.

Microaxial mechanical circulatory support after orthotopic heart transplantation.

AIM: Use of microaxial mechanical circulatory support (MCS) has been reported for severe graft rejection or dysfunction after heart transplantation (HTx). We aimed to assess utilization patterns of microaxial MCS after HTx in adolescents (ages 18 and younger) and adults (ages 19 and older). METHODS: Electronic search was performed to identify all relevant studies on post-HTx use of microaxial support in adults and adolescents. A total of 18 studies were selected and patient-level data were extracted for statistical analysis. RESULTS: All patients (n=23), including adults (n=15) and adolescents (n=8), underwent Impella (Abiomed, Danvers, MA) microaxial MCS after HTx. Median age was 36 [IQR 18-56] years (Adults, 52 [37-59]; adolescents, 16 [15-17]). Primary right ventricular graft dysfunction was an indication exclusively seen in the adults 40% (6/15), while acute graft rejection was present in 46.7% (7/15) of adults. Median time after transplant was 9 [0-32] months (Adults, 4 [0-32]; adolescents, 11 [4.5, 45]). Duration of Impella support was comparable between adults and adolescents (5 [2.5-8] vs 6 [5-8] days, p = 0.38). Overall improvement was observed both in median LV ejection fraction (23.5% [11.3-28] to 42% [37.8-47.3], p < 0.01) and cardiac index (1.8 [1.2-2.6] to 3 [2.5-3.1], p < 0.01). Retransplantation was required in four adolescents (50%, 4/8). Survival to discharge was achieved by 60.0% (9/15) of adults and 87.5% (7/8) of adolescents respectively (p = 0.37). CONCLUSION: Indications for microaxial MCS appear to vary between adult and adolescent patients. Overall improvement in LVEF and cardiac index was observed, however, with suboptimal survival to discharge.