Strategies for the Surgical Management of Highly Aggressive Williams Syndrome Aortopathy: A Three Case Report.

Severe aortopathy in Williams syndrome can sometimes present with an initial ascending aortic pathology, followed in short order by more distal multilevel obstruction and recurrence requiring reintervention. In this series, an early, comprehensive surgical approach using a combination of various access and perfusion strategies yielded excellent long-term results.

Surgical Management of Complex Aortic Valve Disease in Young Adults: Repair, Replacement, and Future Alternatives.

The ideal aortic valve substitute in young adults remains unknown. Prosthetic valves are associated with a suboptimal survival and carry a significant risk of valve-related complications in young patients, mainly reinterventions with tissue valves and, thromboembolic events and major bleeding with mechanical prostheses. The Ross procedure is the only substitute that restores a survival curve similar to that of a matched general population, and permits a normal life without functional limitations. Though the risk of reintervention is the Achilles' heel of this procedure, it is very low in patients with aortic stenosis and can be mitigated in patients with aortic regurgitation by tailored surgical techniques. Finally, the Ozaki procedure and the transcatheter aortic valve implantation are seen by many as future alternatives but lack evidence and long-term follow-up in this specific patient population.

Septal myectomy in the era of genetic testing.

BACKGROUND: Hypertrophic obstructive cardiomyopathy (HOCM) is one of the most common genetic cardiac diseases and encompasses an array of clinical presentations. Little is known about the impact of genetic background on outcomes after septal myectomy (SM). The aim of this study was to evaluate the effect of specific genetic mutations on midterm outcomes in adults undergoing SM for HOCM. METHODS: From 2003 to 2020, a total of 59 patients (male = 66%, mean age = 52 ± 13) underwent SM after a preoperative genetic test. Patients were divided into two groups according to their test result (positive or negative). Preoperative echocardiograms were examined to identify phenotypical characteristics of each mutation. RESULTS: A total of thirty-one patients (53%) had a positive genetic test. MYBPC3 was the most common mutation (15/31 patients). Four different phenotypes were identified on preoperative echocardiograms. Overall, Type 1 phenotype was the most common (37% of the cohort). Type 3 was found exclusively in patients with a positive genetic test. Following SM, none of the patients required a redo myectomy or septal ablation. At 10 years, the survival was 97 ± 3% and 100% in patients with a positive and negative genetic test (p = .33), respectively. CONCLUSION: Although our results suggest that the multiple gene mutations present with different characteristics and phenotypes, midterm results of SM appear to be good regardless of genetic mutation presence.

Early and Long-Term Outcomes after Direct Bridge-to-Transplantation with Extracorporeal Membrane Oxygenation.

BACKGROUND: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as direct bridge-to-transplantation (dBTT) remains controversial. We compared the short- and long-term outcomes of adult patients undergoing urgent heart transplantation (HT) with (dBTT) and without (non-BTT) VA-ECMO support at the time of HT. METHODS: Adults who underwent urgent HT in two institutions were assessed (N = 133; dBTT: N = 34 and non-BTT: N = 99). Patient characteristics, donor characteristics, in-hospital outcomes, and overall survival were compared. Mean follow up was 77±38 months and was 100% complete. Mortality predictors were identified using univariate and multivariate analyses. RESULTS: Before HT, patients with dBTT had higher rates of ischemic cardiomyopathy, acute kidney injury, liver failure, respiratory failure, and longer graft ischemia times. More patients in the dBTT group had complications, such as requiring VA-ECMO postoperatively (dBTT=50% vs. non-BTT=20%, P < 0.01). Hospital deaths (dBTT=23% vs. non-BTT=19%, P = 0.58), one-year (74% vs. 80%) and five-year survival (62% vs. 75%, P = 0.74 for overall survival) were not significantly different. The MELD-XI score and previous cardiac surgery were independent predictors of hospital mortality. CONCLUSION: Direct bridge-to-transplantation in patients on VA-ECMO support was not associated with worse long-term outcomes compared with non-VA-ECMO urgent HT, especially in recipients without any associated organ failure and a low MELD-XI score before HT.

Sex-Related Differences in Patients Undergoing Thoracic Aortic Surgery.

BACKGROUND: Contemporary outcomes after surgical management of thoracic aortic disease have improved; however, the impact of sex-related differences is poorly understood. METHODS: A total of 1653 patients (498 [30.1%] female) underwent thoracic aortic surgery with hypothermic circulatory arrest between 2002 and 2017 in 10 institutions of the Canadian Thoracic Aortic Collaborative. Outcomes of interest were in-hospital death, stroke, and a modified Society of Thoracic Surgeons-defined composite for mortality or major morbidity (stroke, renal failure, deep sternal wound infection, reoperation, prolonged ventilation). Multivariable logistic regression was used to determine independent predictors of these outcomes. RESULTS: Women were older (mean±SD, 66±13 years versus 61±13 years; P<0.001), with more hypertension and renal failure, but had less coronary disease, less previous cardiac surgery, and higher ejection fraction than men. Rates of aortic dissection were similar between women and men. Rates of hemiarch, and total arch repair were similar between the sexes; however, women underwent less aortic root reconstruction including aortic root replacement, Ross, or valve-sparing root operations (29% versus 45%; P<0.001). Men experienced longer cross-clamp and cardiopulmonary bypass times, but similar durations of circulatory arrest, methods of cerebral perfusion, and nadir temperatures. Women experienced a higher rate of mortality (11% versus 7.4%; P=0.02), stroke (8.8% versus 5.5%; P=0.01), and Society of Thoracic Surgeons-defined composite end point for mortality or major morbidity (31% versus 27%; P=0.04). On multivariable analyses, female sex was an independent predictor of mortality (odds ratio, 1.81; P<0.001), stroke (odds ratio, 1.90; P<0.001), and Society of Thoracic Surgeons-defined composite end point for mortality or major morbidity (odds ratio, 1.40; P<0.001). CONCLUSIONS: Women experience worse outcomes after thoracic aortic surgery with hypothermic circulatory arrest. Further investigation is required to better delineate which measures may reduce sex-related outcome differences after complex aortic surgery.

Mitral repair and the robot: a revolutionary tool or marketing ploy?

PURPOSE OF REVIEW: In this review, we discuss the current evidence supporting each minimally invasive mitral repair approach and their associated controversies. RECENT FINDINGS: Current evidence demonstrates that minimally invasive mitral repair techniques yield similar mitral repair results to conventional sternotomy with the benefits of shorter hospital stay, quicker recovery, better cosmesis and improved patient satisfaction. Despite this, broad adoption of minimally invasive mitral repair is still not achieved. Two main approaches of minimally invasive mitral repair exist: endoscopic mini-thoracotomy and robotic-assisted approaches. SUMMARY: Both minimally invasive approaches share many commonalities; however, most centres are strongly polarized to one approach over another creating controversy and debate about the most effective minimally invasive approach.

The effect of storage solutions, gene therapy, and antiproliferative agents on endothelial function and saphenous vein graft patency.

Vein graft failure remains a major concern after coronary artery bypass graft operations, and is initiated by loss of endothelial cell integrity. Preservation of saphenous vein grafts in the optimal solution after meticulous harvesting can limit the endothelial damage. Despite both experimental and clinical results in favor of buffered solutions, normal saline is still the most widely used solution. This review examines the literature to identify the most optimal storage solutions currently available for vein graft preservation.

Tackling the Issue of High Postoperative Pacemaker Implantation Rates in Sutureless Aortic Valve Replacement: Should Balloon Inflation be Removed from the Implantation Method of the Perceval Prosthesis?

BACKGROUND: Sutureless aortic valve replacement (AVR) is an emerging alternative to standard AVR in elderly and high-risk patients. This procedure is associated with a high rate of postoperative permanent pacemaker implantation (PPI). The study aim was to assess the impact on the rate of PPI of implanting the Perceval prosthesis without using balloon inflation. METHODS: A total of 159 patients who underwent sutureless AVR using the Perceval prosthesis was included. Balloon inflation was used in 132 patients (Balloon group) and not used in the remaining 27 (No-Balloon group). Clinical, echocardiographic and electrocardiographic outcomes were assessed. RESULTS: There was no significant difference in PPI rate between the two groups (26% for Balloon group versus 22% in No-Balloon group; p = 0.700). Balloon inflation had no significant impact on the incidence of paravalvular leaks (p = 0.839), or on the need to return to cardiopulmonary bypass (CPB) intraoperatively due to paravalvular leak or unsatisfactory deployment (p >0.999). Mean and peak transaortic pressure gradients were similar between the two groups (p = 0.417 and p = 0.522, respectively). Cross-clamp and CPB times were shorter in the No-Balloon group (49.6 ± 15.9 min versus 61.1 ± 25.6 min and 64.1 ± 26.3 min versus 79.6 ± 35.4 min, respectively; p = 0.027 and p = 0.012, respectively). CONCLUSIONS: The two groups had similar postoperative PPI rates. Implanting the Perceval prosthesis without balloon inflation is safe and had no impact on paravalvular leaks, intraoperative complications or hemodynamic results. Reductions in aortic cross-clamp time and CPB time were observed when the balloon was not used.

Del Nido cardioplegia in the setting of minimally invasive aortic valve surgery.

The purpose of this study is to report our experience with del Nido cardioplegia (DNC) in the setting of minimally invasive aortic valve surgery. Forty-six consecutive patients underwent minimally invasive aortic valve replacement (AVR) through a "J" ministernotomy: twenty-five patients received the DNC (Group 1) and 21 patients received standard blood cardioplegia (SBC) (Group 2). The rate of ventricular fibrillation at unclamping was significantly lower in the DNC group (12% vs 52%, p=0.004), as well as postoperative creatinine kinase-MB (CK-MB) values (11.4±5.2 vs 17.7±6.9 µg/L, p=0.004). There were no deaths, myocardial infarctions or major complications in either group. Less postoperative use of intravenous insulin (28% vs 81%, p<0.001) was registered in the DNC group. In conclusion, the DNC is easy to use and safe during minimally invasive AVR, providing a myocardial protection at least equivalent to our SBC, improved surgical efficiency, minimal cost and less blood glucose perturbations.

Influence of preoperative aortic regurgitation on long-term autograft durability and dilatation in children and adolescents undergoing the Ross procedure.

OBJECTIVE: Primary aortic insufficiency (AI) is a risk factor for autograft reintervention in adults undergoing the Ross procedure. We sought to examine the influence of preoperative AI on autograft durability in children and adolescents. METHODS: From 1993 to 2020, 125 consecutive patients between ages 1 and 18 underwent a Ross procedure. The autograft was implanted using a full-root technique in 123 (98.4%) and included in a polyethelene terephthalate graft in 2 (1.6%). Patients with aortic stenosis (aortic stenosis group) (n = 85) were retrospectively compared with those with AI or mixed disease (AI group) (n = 40). Median length of follow-up was 8.2 years (interquartile range, 3.3-15.4 years). The primary end point was the incidence of severe AI or autograft reintervention. Secondary end points included changes in autograft dimensions analyzed using mixed-effect models. RESULTS: The incidence of severe AI or autograft reintervention was 39.0% ± 13.0% in the AI group and 8.8% ± 4.4% in the aortic stenosis group at 15 years (P = .02). Annulus z scores increased in both aortic stenosis and AI groups over time (P < .001). However, the annulus dilated at a faster rate in the AI group (absolute difference, 3.8 ± 2.0 vs 2.5 ± 1.7; P = .03). Sinus of Valsalva z scores increased in both groups as well (P < .001), but at similar rates over time (P = .11). CONCLUSIONS: Children and adolescents with AI undergoing the Ross procedure have higher rates of autograft failure. Patients with preoperative AI have more pronounced dilatation at the annulus. Akin to adults, a surgical aortic annulus stabilization technique that modulates growth is needed in children.

Tetralogy of Fallot in Low- and Middle-Income Countries.

Low- and middle-incomes countries (LMICs) have limited resources for the diagnosis and treatment of congenital heart diseases such as tetralogy of Fallot. This is in part due to lack of infrastructures, financial means, and expertise. As a result, patients undergo surgery much later than in high-income countries. This delay in treatment results in right ventricular dysfunction, cardiac arrhythmias, and poor psychomotor development-complications that are all related to chronic hypoxia. There are limited data and a few small studies of patients treated for tetralogy of Fallot in LMICs, and, therefore, the aim of this review is to analyse and summarize the surgical outcomes of this LMIC population.

Dans les pays à revenu faible ou intermédiaire (PRFI), les ressources sont limitées pour diagnostiquer et prendre en charge les cardiopathies congénitales comme la tétralogie de Fallot. Cette situation est attribuable en partie au manque d'infrastructures, de moyens financiers et d'expertise. Les patients subissent donc une correction chirurgicale beaucoup plus tard que dans les pays à revenu élevé. Les délais de traitement peuvent entraîner une dysfonction ventriculaire droite, une arythmie cardiaque et des problèmes de développement psychomoteur : des complications toutes liées à l'hypoxie chronique. Il existe des données limitées et quelques études de faible envergure sur des patients traités pour une tétralogie de Fallot dans les PRFI. L'objectif du présent article de synthèse est donc d'analyser et de résumer les issues des interventions chirurgicales dans les PRFI pour cette population.

Aortic insufficiency following balloon aortic valvuloplasty does not impact long-term autograft durability after the Ross procedure.

OBJECTIVE: Preoperative aortic insufficiency (AI) is associated with inferior autograft durability after the Ross procedure. However, many patients with aortic stenosis (AS) undergo balloon aortic valvuloplasty (BAV) early and present with longstanding AI before Ross. We studied how BAV and subsequent valvular pathology impacts autograft durability. METHODS: Patients undergoing the Ross operation from 1993 to 2020 were identified. Those who underwent BAV before Ross were compared with patients who did not undergo BAV and underwent Ross for predominant AI (AI group) or AS (AS group). Those who underwent previous open surgical aortic valve intervention were excluded. Primary outcome of interest was autograft failure, defined as a composite of autograft reintervention or severe insufficiency. RESULTS: A total of 198 patients were included. Seventy-nine (39.9%) underwent BAV and subsequently underwent the Ross for predominant AI (45.6%) or AS (54.4%). Of patients who did not undergo BAV, 66 (33.3%) presented with predominant AI and 53 (26.8%) with AS. Freedom from autograft failure at 15 years was 90%, 92%, and 62% in BAV, AS, and AI groups, respectively. The AI group was at significantly increased risk of long-term autograft failure (hazard ratio, 5.6; P = .01), whereas the AS and BAV groups had similar, low risk (hazard ratio, 1.1; P = .91). Autograft durability was similar among patients who received BAV and presented with AS or AI before the Ross (P = .84). CONCLUSIONS: BAV before the Ross procedure is common in patients with AS. These patients have excellent long-term autograft durability regardless of preoperative valvular pathology and should strongly be considered for the Ross operation.

Long-term autograft dilation and durability after the Ross procedure are similar in infants, children, and adolescents with primary aortic stenosis.

BACKGROUND: Autograft durability and remodeling are thought to be superior in younger pediatric patients after the Ross operation. We sought to delineate the fate of autografts across the pediatric age spectrum in patients with primary aortic stenosis (AS). METHODS: We retrospectively reviewed patients age ≤18 years with primary AS who underwent the Ross operation between 1993 and 2020. Patients were categorized by age. The primary endpoint was autograft dimensional change, and secondary endpoints were severe neo-aortic insufficiency (AI) and autograft reintervention. RESULTS: A total of 119 patients underwent the Ross operation, including 37 (31.1%) in group I (age <18 months), 24 (20.2%) in group II (age 18 months-8 years), and 58 (48.7%) in group III (age 8-18 years). All groups exhibited similar annular growth rates within the first 5 postoperative years, followed by a collective decrease in annulus growth rates from year 5 to year 10. Group III experienced rapid sinus dilation in the first 5 years, followed by stabilization of the sinus z-score from year 5 to year 10, whereas groups I and II demonstrated stable sinus z-scores over 10 years. There were 4 early deaths (3.4%) and 2 late deaths (1.7%) at a median follow-up of 8.1 years (range, 0.01-26.3 years). At 15 years, the incidences of severe neo-AI (0.0 ± 0.0% vs 0.0 ± 0.0% vs 3.9 ± 3.9%; P = .52) and autograft reintervention (8.4 ± 6.0% vs 0.0 ± 0.0% vs 2.4 ± 2.4%; P = .47) were similar in the 3 groups. CONCLUSIONS: Age at the time of Ross operation for primary AS does not influence long-term autograft remodeling or durability. Other physiologic or technical factors are likely greater determinants of autograft fate.

Transcatheter Closure of Atrial and Ventricular Septal Defects: JACC Focus Seminar.

The field of congenital interventional cardiology has experienced tremendous growth in recent years. Beginning with the development of early devices for transcatheter closure of septal defects in the 1970s and 1980s, such technologies have evolved to become a mainstay of treatment for many atrial septal defects (ASDs) and ventricular septal defects (VSDs). Percutaneous device closure is now the preferred approach for the majority of secundum ASDs. It is also a viable treatment option for selected VSDs, though limitations still exist. In this review, the authors describe the current state of transcatheter closure of ASDs and VSDs in children and adults, including patient selection, procedural approach, and outcomes. Potential areas for future evolution and innovation are also discussed.

Transcatheter Cardiac Interventions in the Newborn: JACC Focus Seminar.

For neonates with critical congenital heart disease requiring intervention, transcatheter approaches for many conditions have been established over the past decades. These interventions may serve to stabilize or palliate to surgical next steps or effectively primarily treat the condition. Many transcatheter interventions have evidence-based records of effectiveness and safety, which have led to widespread acceptance as first-line therapies. Other techniques continue to innovatively push the envelope and challenge the optimal strategies for high-risk neonates with right ventricular outflow tract obstruction or ductal-dependent pulmonary blood flow. In this review, the most commonly performed neonatal transcatheter interventions will be described to illustrate the current state of the field and highlight areas of future opportunity.

Autograft remodeling after the Ross procedure by cardiovascular magnetic resonance imaging: Aortic stenosis versus insufficiency.

BACKGROUND: Studies suggest that patients undergoing the Ross procedure for aortic insufficiency are at greater risk of autograft dilatation than those with aortic stenosis. By using a tailored Ross technique to mitigate autograft dilatation in patients with aortic insufficiency, we aimed to compare the biomechanical and morphologic remodeling of the autograft at 1 year between patients with aortic insufficiency and patients with aortic stenosis. METHODS: A total of 210 patients underwent a Ross procedure (2011-2016). Of those, 86 patients (mean age 43 ± 13 years; 32% were female) completed preoperative and postoperative cardiovascular magnetic resonance imaging. A total of 71 studies were suitable for analysis: 41 patients with aortic stenosis and 30 patients with aortic insufficiency. Nine healthy adults were used as controls. Autograft root dimensions, individual sinus volumes, and distensibility were measured using cardiovascular magnetic resonance. RESULTS: At 1 year, there was no difference in autograft root dimensions between patients with aortic stenosis (mean annulus 25.1 ± 3.1 mm and sinus diameters 35 ± 4.1 mm) and patients with aortic insufficiency (26.6 ± 3 mm and 37.1 ± 3.5 mm; P = .12 and .06, respectively). Relative sinus of Valsalva volumes were symmetrical in the aortic stenosis (right 34.8% ± 4%, left 33.7% ± 3.5%, noncoronary 31.4% ± 3.2%) and aortic insufficiency groups (34.8% ± 3.9%, 33.8% ± 2.8%, 31.3% ± 3.7%, P = .85, .92, and .82), and similar to those of healthy adults. Aortic root distensibility was reduced in both groups compared with healthy adults (P = .003), but was similar between aortic stenosis (3.12 ± 1.58 × 10-3 mm Hg-1) and aortic insufficiency (3.04 ± 1.15 × 10-3 mm Hg-1; P = .9). CONCLUSIONS: Using a tailored technique, there were no differences in the morphologic or biomechanical remodeling of the autograft root 1 year after the Ross procedure between patients with aortic stenosis and patients with aortic insufficiency. However, autograft roots are stiffer than native aortic roots.

Interventions for Congenital Atrioventricular Valve Dysfunction: JACC Focus Seminar.

Innovation and creativity have led to tremendous advancements in the care and management of patients with congenital heart disease (CHD) that have resulted in considerably increased survival. Catheter-based interventions have contributed significantly to these advancements. However, catheter-based interventions for congenital lesions of the atrioventricular (AV) valves have been limited in scope and effectiveness mainly because of patient size and anatomical challenges. Thus, surgical repair and replacement for congenital AV valve lesions have remained the preferred therapy. However, the ongoing transcatheter heart valve revolution has led to techniques and technologies that are changing the landscape, particularly for adult CHD patients. Many devices for AV valve repair and replacement are being studied in adult patients without CHD, and translation of select practices to CHD patients has begun, with many more to come. Transcatheter AV valve interventions represent exciting opportunities for the growing numbers of adult CHD patients.

The Ross procedure in patients older than 50: A sensible proposition?

BACKGROUND: The Ross procedure offers several advantages in nonelderly adults; however, the optimal age cutoff remains undetermined. The aim of this study was to compare the safety and mid-term outcomes after the Ross procedure in adult patients age ≤50 years and those age >50 years. METHODS: Between 2011 and 2019, 497 consecutive patients (mean age, 47 ± 12 years; 73% male) underwent a Ross procedure in 5 Canadian centers and were followed prospectively. Of these patients, 232 (47%) were age >50 years (mean, 57 ± 4 years) and 265 (53%) were age ≤50 years (mean, 38 ± 10 years). Early and mid-term outcomes were compared between the 2 groups. RESULTS: Patients age >50 years had more comorbidities: diabetes (14% vs 4%; P < .01), chronic obstructive pulmonary disease (8% vs 2%; P < .01), and coronary artery disease (17% vs 3%; P < .01). In contrast, patients age ≤50 years had more redo surgeries (24% vs 8%; P < .01), pure aortic regurgitation (21% vs 6%; P < .01) and unicuspid valves (42% vs 9%; P < .01). In-hospital mortality was similar in the 2 groups (0.4% vs 0.4%; P = .99). There were no between-group differences in perioperative complications. The cumulative incidence of reintervention was similar at 6 years (>50 years: 0.7 ± 0.7%; ≤50 years: 4 ± 2%; P = .12). Survival at 6 years was 98 ± 2% in patient age >50 years versus 96 ± 2% in those age ≤50 years (P = .43), similar to the age- and sex-matched general population. CONCLUSIONS: The Ross procedure is a safe operation in patients age >50 years and provides excellent hemodynamics, stable valve function, and restored survival at mid-term follow-up. In expert centers, it should be considered as an alternative in selected patients age >50 years.

Pulmonary homograft dysfunction after the Ross procedure using decellularized homografts-a multicenter study.

OBJECTIVES: Pulmonary homograft dysfunction is a limitation after the Ross procedure. Decellularized pulmonary homografts can potentially mitigate this complication. The aim of this study was to examine the incidence, predictors, progression, and morphology of pulmonary homograft dysfunction using data from the Canadian Ross Registry. METHODS: From 2011 to 2019, 466 consecutive patients (mean age: 47 ± 12 years, 73% male) underwent a Ross procedure using a decellularized cryopreserved pulmonary homograft (SynerGraft SG; CryoKife, Kennesaw, Ga). Pulmonary homograft dysfunction was defined as any of the following: peak pulmonary gradient ≥30 mm Hg, pulmonary regurgitation >2, or pulmonary homograft reintervention. Patients meeting ≥1 of these criteria (n = 30) were compared with the rest of the cohort (n = 436). Median follow-up is 2.2 years (maximum = 8.5 years) and 99% complete (1176 patient-years). RESULTS: The cumulative incidence of pulmonary homograft dysfunction was 11 ± 2% at 6 years. Pulmonary homograft stenosis was the most frequent presentation (n = 28 patients, 93%). Morphologically, stenosis occurred most often along the conduit (59%). Overall, 4 patients required homograft reintervention. At 6 years, the cumulative incidence of homograft reintervention was 3 ± 1%. The instantaneous risk was greatest in the first year after surgery (3.5%/year) and decreased to <1%/year thereafter. Patient age <45 years was the only independent risk factor associated with pulmonary homograft dysfunction (hazard ratio, 3.1, 95% confidence interval, 1.1-8.6, P = .03). CONCLUSIONS: The use of decellularized cryopreserved pulmonary homografts results in a low incidence of dysfunction and reintervention after the Ross procedure. The risk is greater in the first postoperative year. Younger age is the only independent risk factor for pulmonary homograft dysfunction.

Learning Curve in Left Ventricular Assist Device Implantation: Low Volumes Do Not Equate Bad Outcomes.

INTRODUCTION: Most implantations of left ventricular assist devices (LVAD) are performed in low-volume centers. This study aimed to evaluate the procedural learning curve of HeartMate II (HM2) implantations by comparing outcomes between two time periods in a low-volume center. METHODS: All 51 consecutive patients undergoing HM2 implantation between January 2009 and December 2017 were reviewed and allocated into 2 groups: early-era group (from 2009 to 2014; n=25) and late-era group (from 2015 to 2017; n=26). The primary outcome was the 90-day mortality rate, and the secondary outcome was a composite of mortality, neurological event, reoperation for bleeding, need for temporary right ventricular assist device, and pump thrombosis at 90 days. Median follow-up time was 51 months (0-136). A cumulative sum (CUSUM) control analysis was used to establish a threshold of implantations that optimizes outcomes. RESULTS: Patients in the early era had a higher rate of diabetes, previous stroke, and inotrope support before HM2 implantation. The 90-day mortality rate was not significantly higher in the early era (24% vs. 15%, P=0.43), but the composite endpoint was significantly higher (76% vs. 42%, P=0.01). The CUSUM analysis found a threshold of 23 operations after which the composite endpoint was optimized. CONCLUSION: Patients undergoing HM2 implantation in a low-volume center have improving outcomes with number of cases and optimized results after a threshold of 23 cases. Significant changes in patient selection, surgical techniques, and patient management might lead to improved outcomes after LVAD implantation.