Stulak, John M.

Background Dual antiplatelet therapy (DAPT) is recommended over single antiplatelet therapy (SAPT) in patients following coronary artery bypass grafting (CABG). The compilation of evidence has focused on the efficacy of DAPT to limit risk of graft occlusion, however the safety, especially in the on-pump CABG population, is less well described. The aim of this study was to assess the safety of DAPT versus SAPT after on-pump CABG. Methods This was a single-center, retrospective cohort analysis of adult patients following isolated on-pump CABG between January 2012 and December 2019 not on oral anticoagulation at discharge. The primary endpoint was occurrence of a composite bleeding event identified by pre-specified ICD codes. Secondary endpoints consisted of 30-day and 1-year mortalities along with individual bleeding components. Results Of the 2341 patients included 1250 patients were in the SAPT arm and 1091 patients in the DAPT arm. The study populations differed by age, prior MI, PAD, and CHF status/stage. Bleeding events occurred in a total of 70 patients (3.0%), with 36 patients (2.9%) in the SAPT arm and 34 patients (3.1%) in the DAPT arm ( P = .74). 30-day (SAPT 0.7% vs DAPT 0.4%) and 1-year (SAPT 3.3% vs DAPT 2.3%) mortality were not significantly different between groups. The most frequent bleed event was in the gastrointestinal tract. Conclusion In this study, DAPT was not associated with an increase in composite bleeding compared to SAPT. This study could reduce the barrier to prescribing of DAPT given previous efficacy data.

AbstractOver the last half‐century, left ventricular assist device (LVAD) technology has progressed from conceptual therapy for failed cardiopulmonary bypass weaning to an accepted destination therapy for advanced heart failure. The history of LVAD engineering is defined by an initial development phase, which demonstrated the feasibility of such an approach, to the more recent three major generations of commercial devices. In this review, we explore the engineering challenges of LVADs, how they were addressed over time, and the clinical outcomes that resulted from each major technological development. The first generation of commercial LVADs were pulsatile devices, which lacked the appropriate durability due to their number of moving components and hemocompatibility. The second generation of LVADs was defined by replacement of complex, pulsatile pumps with primarily axial, continuous‐flow systems with an impeller in the blood passageway. These devices experienced significant commercial success, but the presence of excessive trauma to the blood and in‐situ bearing resulted in an unacceptable burden of adverse events. Third generation centrifugal‐flow pumps use magnetically suspended rotors within the pump chamber. Superior outcomes with this newest generation of devices have been observed, particularly with respect to hemocompatibility‐related adverse events including pump thrombosis, with fully magnetically levitated devices. The future of LVAD engineering includes wireless charging foregoing percutaneous drivelines and more advanced pump control mechanisms, including synchronization of the pump flow with the native cardiac cycle, and varying pump output based on degree of physical exertion using sensor or advanced device‐level data triggers.

Abstract Background Preoperative risk scores facilitate patient selection, but postoperative risk scores may offer valuable information for predicting outcomes. We hypothesized that the postoperative Sequential Organ Failure Assessment (SOFA) score would predict mortality after left ventricular assist device (LVAD) implantation. Methods We retrospectively reviewed data from 294 continuous‐flow LVAD implantations performed at Mayo Clinic Rochester during 2007 to 2015. We calculated the EuroSCORE, HeartMate‐II Risk Score, and RV Failure Risk Score from preoperative data and the APACHE III and Post Cardiac Surgery (POCAS) risk scores from postoperative data. Daily, maximum, and mean SOFA scores were calculated for the first 5 postoperative days. The area under receiver‐operator characteristic curves (AUC) was calculated to compare the scoring systems' ability to predict 30‐day, 90‐day, and 1‐year mortality. Results For the entire cohort, mortality was 5% at 30 days, 10% at 90 days, and 19% at 1 year. The Day 1 SOFA score had better discrimination for 30‐day mortality (AUC 0.77) than the preoperative risk scores or the APACHE III and POCAS postoperative scores. The maximum SOFA score had the best discrimination for 30‐day mortality (AUC 0.86), and the mean SOFA score had the best discrimination for 90‐day mortality (AUC 0.82) and 1‐year mortality (AUC 0.76). Conclusions We observed that postoperative mean and maximum SOFA scores in LVAD recipients predict short‐term and intermediate‐term mortality better than preoperative risk scores do. However, because preoperative and postoperative risk scores each contribute unique information, they are best used in concert to predict outcomes after LVAD implantation.

Abstract OBJECTIVES The purpose of this study was to assess the safety and efficacy of direct cannulation of the ascending aorta in comparison with cannulating peripheral arteries. METHODS We retrospectively analysed type A dissection patients [n = 107; median (interquartile range [IQR]) age, 64 [53–73] years] from January 2008 to March 2018. The cohort was divided into 2 groups: direct ascending aorta cannulation (group A, n = 47; median [IQR] age, 69 [54–74] years; 34% female) and non-aortic cannulation (group B, n = 60; median [IQR] age, 62 [52–72] years; 20% female). Postoperative outcomes and long-term survival were compared. RESULTS Baseline characteristics were not significantly different between the 2 groups, except for higher creatinine in group B (median 0.9 vs 1.1, P = 0.028) and higher prevalence of dyslipidaemia in group A (58.7% vs 38.3%, P = 0.037). Overall early mortality was 12.1% (n = 13); 12.8% (n = 6) in group A and 11.7% (n = 7) in group B (P = 0.863). The incidence of stroke was 10.6% (n = 5) in group A and 6.7% (n = 4) in group B (P = 0.463). After adjusting for CPB and circulatory arrest times, there was no group difference in the length of ICU (P = 0.257) or hospital stay (P = 0.118), all-cause reoperation (P = 0.709), peak postoperative creatinine (P = 0.426) and lactate values (n = 60; P = 0.862). Overall survival at 1, 3 and 5 years was 84%, 78% and 73%, respectively, with no difference between the 2 groups after adjustment (P = 0.629). CONCLUSIONS Direct cannulation of the ascending aorta is a safe cannulation strategy for type A dissection repair, offering the opportunity for rapid arterial cannulation and antegrade perfusion.

Abstract Background Lactate hydrogenase (LDH) is a common biomarker utilized in the detection and monitoring of left ventricular assist device (LVAD) hemolysis and thrombosis. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) are common laboratory tests that can be used to calculate the De Ritis ratio and the De Ritis adjusted AST. Methods A retrospective review of LVAD patients was performed to identify three cohorts of patients: those with confirmed pump thrombosis after device exchange, those with LVAD‐related hemolysis who were medically managed without pump exchange, and those who did not meet these criteria and served as the control cohort. Evaluation of AST, AST/ALT ratio (referred to as the De Ritis ratio) as well as AST x (AST/ALT) or the De Ritis‐adjusted AST (DRA) was performed. Results There were 29 patients who underwent device exchange for thrombosis, 25 patients who were diagnosed with hemolysis and treated medically (clopidogrel ( N = 6), heparin ( N = 13), tirofiban ( N = 8), eptifibatide ( N = 2), and some received more than one of these treatments), and 425 control patients. A qualitatively comparable relative and absolute rise in DRA and LDH were found in both surgically managed pump thrombosis and suspected device‐related hemolysis. Conclusions Both AST and LDH as well DRA are significantly associated with pump thrombosis ( p < 0.0001 for each). DRA is a potential screening biomarker for hemolysis and device thrombosis in stable left ventricular assist device patients.

Abstract Background Hemocompatibility‐related adverse events (HRAE) negatively influence survival. However, no study has examined the impact of these events on health‐related quality of life (HRQOL) and functional outcomes following continuous‐flow left ventricular assist device implantation (CF‐LVAD). We assessed the impact of HRAE events on HRQOL and hypothesized that HRAE's adversely impact HRQOL and functional outcomes. Methods INTERMACS database identified patients undergoing primary CF‐LVAD implantation from 2008 to 2017. HRAEs included stroke, non‐surgical bleeding, hemolysis, and pump thrombosis and were identified as defined in the literature. HRAEs were further stratified as Tier 1–2 and disabling stroke events. Time‐series analysis was executed for HRAE patients with values pre‐HRAE, post‐HRAE, and closest to 12 months follow up. Local polynomial regression curves modeling individual patients were superimposed into “spaghetti” plots. Results All HRQOL and functional metrics improved in patients over time, despite HRAE complications. However, these patient metrics were significantly reduced compared to the non‐HRAE cohort. Advanced data visualization techniques noted a decline after experiencing an HRAE with a subsequent recovery to baseline levels or higher. Six‐minute walk test (6MWT) was noted to be most affected in the post‐HRAE period but recovered similar to other metrics. Conclusions The burden of HRAE following CF‐LVAD implantation did not negatively impact the quality of life. However, the 6MWT did not increase in the post‐HRAE period in all HRAE patients. Improvement of heart failure symptoms after CF‐LVAD coupled with optimal management following the HRAE act to preserve the enhanced quality of life.

Introduction: Various risk models have been used to predict mortality after implantation of continuous-flow ventricular assist devices (CF-VADs). Discriminatory power and predictive accuracy vary, and there is a need to develop and validate a contemporary risk score in a large multicenter patient cohort. Hypothesis: We sought to develop an early mortality risk score utilizing a large voluntary research registry of patients implanted with CF-VADs, with the focus on increased discriminatory power. Methods: From May 2004 to May 2015, 1150 patients in the Mechanical Circulatory Support Research Network (MCSRN) registry were randomly divided into equal-sized derivation and validation samples (n=575, each group). Candidate predictors from the derivation sample were subjected to backward stepwise logistic regression until the model with lowest Akaike information criterion value was identified for predicting 90-day mortality. A risk score was developed based on the variables and their respective regression coefficients in the final model. Discriminatory power of the risk score was evaluated using receiver operating characteristic analysis, and calibration was assessed using Hosmer-Lemeshow goodness of fit test. Results: Overall 90-day mortality was 9.4% (n=99). The final logistic regression model consisted of 9 predictors: Age at implant, preoperative mechanical ventilation, serum total bilirubin, hemoglobin, tricuspid valve regurgitation severity, left ventricular end-diastolic diameter, cardiac index, pulmonary capillary wedge pressure, and destination therapy (DT) as an indication for pump placement. The area under the curve was 0.86 in the derivation sample (95% CI, 0.75-0.97) and 0.75 in the validation sample (95% CI, 0.63-0.86). Hosmer-Lemeshow goodness of fit test yielded insignificant values in both samples (p=0.75, p=0.58) consistent with good calibration. Conclusions: The proposed 90-day mortality MCSRN risk score provides highest-to-date discriminatory power when compared to already published models. The risk score is applicable to a contemporary large cohort of patients implanted with CF-VADs for either indication (bridge or DT).

Introduction and hypothesis: Recent data have indicated an increase in the rate of early, confirmed pump thrombosis of the HeartMate II (HMII) left ventricular assist device. Factors related to this increase were not known, but one of the hypotheses was change in clinical management over time. The PREVENT ( PREVEN tion of Heartmate II Pump T hrombosis through Clinical Management) study was designed to evaluate the impact of clinical practices developed to reduce the risk of HMII pump thrombosis. Methods: PREVENT is a prospective, multi-center, single-arm, non-randomized study of up to 300 patients at up to 25 sites. Patient and pump management, including implant technique, anticoagulation, and pump settings are guided by protocol (Table 1). Primary endpoint is incidence of confirmed pump thrombosis at 3 months, with a total follow-up of 6 months. Presented here are the preliminary results from the first 100 subjects enrolled. Results: Median age was 61 years [25-79], 87% were male, and 79% were destination therapy. At implant, 9% were in INTERMACS Profile1, 68% Profiles 2-3, and 22% Profiles 4-7. Preliminary analysis of 90-day outcomes demonstrated an incidence of 1% for confirmed and 2% for suspected thrombosis with a 38% incidence of INTERMACS-defined bleeding. Adherence to the protocol recommendations was as follows: 91% of the pumps were anchored, 97% of the patients were bridged with heparin, median pump speed at 1 month was 9190 [range: 8400-10000], with 93% of the patients having a pump speed > 8600, and 78% of the patients having pump speeds > 9000. Median INR per patient was 2.2 [IQR: 2.0-2.4]. Overall Kaplan-Meier survival was 93%. Conclusions: Preliminary results are encouraging and suggest good adherence to the PREVENT protocol and low rates of pump thrombosis without a resultant increase in bleeding complications. Overall survival after HM II implantation remains excellent.

ABSTRACT Background The COVID-19 pandemic affected graduate medical education (GME) by decreasing elective procedures and disrupting didactic learning activities in 2020. Editorials have hypothesized that resident physicians worked fewer hours, therefore losing valuable experience, but we are not aware of studies that have objectively assessed changes in hours worked. Objective This study aims to identify differences secondary to the COVID-19 pandemic in resident work hours across all specialties at 3 geographically dispersed, integrated academic hospitals in a large sponsoring institution. Methods We obtained de-identified work hour data from all residency programs at Mayo Clinic in Arizona, Florida, and Minnesota. Resident work hours were compared between 2020 and 2019 from March to May. Results Work hours for 1149 and 1118 residents during the pandemic and control periods respectively were compared. Decreases in resident work hours were seen, with the largest decrease demonstrated in April 2020 when 19 of 43 programs demonstrated significantly decreased work hours. Residents worked more hours from home in April 2020 compared to the previous year (Arizona: mean 1 hour in 2019 vs 5.2 hours in 2020, P&lt;.001; Florida: mean 0.7 hour in 2019 vs 6.5 hours in 2020, P&lt;.001; Minnesota: mean 0.8 hour in 2019 vs 10.2 hours in 2020, P&lt;.001). Conclusions The COVID-19 pandemic was associated with a decrease in work hours in some, but not all, specialties. The decrease in on-site work was only partially offset by an increased number of hours worked from home.