Maltais, Simon

Cardiac fistulas present diagnostical and therapeutical challenges due to their variability in size, shape and pathway. Three-dimensional printing is increasingly used to provide a tactile representation that aids in preoperative planning and patient education. We present the case of a female in her 60s who developed a fistula between the left ventricle, right atrium and coronary sinus 2 years after bioprosthetic valve replacement. We used three-dimensional modelling to better understand her cardiac anatomy and optimise our surgical approach. She was discharged home without deficit following an uneventful postoperative course. Three-dimensional printing can improve patient care through tangible demonstration, preoperative planning and trainee education.

Introduction: Baseline hemodynamic parameters have been shown to predict postoperative outcomes such as right ventricular failure (RVF) in LVAD patients. The pressure adjusted heart rate (PaHR) is a hemodynamic parameter that has not been reported in LVAD recipients. Hypothesis: Patients with an elevated PaHR at baseline will have an increased risk of adverse outcomes following LVAD implantation. Methods: Historical cohort study of 273 patients with preoperative invasive hemodynamic assessment before durable LVAD implantation from January 1 st , 2007 to April 10 th 2017. Baseline patient characteristics and hemodynamic parameters were assessed. The primary endpoint was a composite of 30 day mortality, stage 3 acute kidney injury (AKI), and postoperative RVF. Univariate analysis was used to identify predictors of the composite endpoint, which were entered into stepwise backwards multivariate logistic regression to determine independent predictors of the composite outcome. Results: The mean age was 59 and 79% of the patients were male. The median INTERMACS profile was 4 and 166 (60%) of LVADs placed were as destination therapy. The primary composite endpoint was reached by 74 (27%) patient, including 30-day mortality in 13 (5%), severe AKI in 48 (18%) and RVF in 53 (19%). Univariate predictors of the composite endpoint (p <0.05) included atrial fibrillation, INTERMACS profile, home inotropes, preoperative IABP, admission creatinine, baseline Vasoactive-Inotropic Score, mean right atrial pressure (mRAP), mRAP/wedge, mean arterial pressure/mRAP, mean pulmonary artery pressure/mRAP, right ventricular stroke work index (RVSWi), pulmonary artery pulsatility index, and the PaHR. Logistic regression identified PaHR (OR 0.96, 95% CI 0.93-0.99, p=.026), RVSWi (OR 1.002, 95% CI 1.001-1.004, p=.002), home inotropes (OR 0.46, 95% CI 0.22-0.94, p=.034), atrial fibrillation (OR 0.48, 95% CI 0.26-0.88, p=.019) and admission creatinine (OR 0.51, 95% CI 0.34-0.77, p=0.002) as predictors of the composite endpoint. Conclusions: The PaHR is a readily available, novel hemodynamic parameter, that when elevated on baseline hemodynamic assessment can predict those patients at increased risk of postoperative adverse outcomes after durable LVAD implantation.

Introduction: Patients at increased risk of complications following LVAD placement are admitted to the hospital for hemodynamic optimization prior to LVAD implantation, which can include adjustment of medical therapy and/or placement of an IABP. Hypothesis: Prior to LVAD placement patients treated with an IABP during hemodynamic optimization will have similar outcomes despite worse baseline characteristics compared with patients treated medically. Methods: This single-center study included 199 non-inotrope dependent patients who underwent durable LVAD implantation between January 1 st , 2007 and April 10 th 2017. Hemodynamic data was collected retrospectively. Patients who received an IABP were compared to those who did not. Stage 2 or 3 acute kidney injury, right ventricular failure, and 30 day mortality was compared between patients with and without and IABP. Results: The mean age was 62.7 and 82.9% were male; 72 (36.2%) received an IABP. Baseline characteristics between groups were similar. Patients treated with an IABP had worse INTERMACS profiles and worse baseline hemodynamic parameters. The incidence of the primary composite endpoint was similar between patients who had an IABP and those who did not (23.6% vs 19.7%; p=0.517), as were each of the individual endpoints: stage 2 or 3 acute kidney injury (18.1% vs 14.2%; p=0.472), right ventricular failure (13.9% vs 13.4%; p=0.796), and 30 day mortality (6.9 % vs 3.2%; p=0.226). Patients treated with an IABP had greater relative reductions in mean right atrial pressure (-24.1% vs -5.9%; p=0.044), pulmonary artery systolic (-11.7% vs +3.3%; p=<0.001), diastolic (-17.0% vs +12.0%; p=0.015), and mean pressures (-15.2% vs 0.5%; p=<0.001). Conclusions: Despite worse hemodynamic parameters and INTERMACS profile at baseline, ambulatory heart failure patients who received an IABP prior to LVAD implantation did not have an increased incident of stage 2 or 3 acute kidney injury, right ventricular failure, or 30 day mortality, and had more favorable reductions in right atrial and pulmonary artery pressures. These results suggest that the use of the IABP prior to LVAD implantation in non-inotrope dependent patients with poor baseline hemodynamics may mitigate the risk of postoperative complications.

Introduction: Age ≥ 70 is used to exclude patients from cardiac transplantation. Elderly patients may be offered left ventricular assist device (LVAD) therapy as an alternative. It remains poorly defined how they respond to LVAD support. Hypothesis: Elderly patients have LVAD outcomes that are non-inferior to younger patients. Methods: Data on 1,149 continuous-flow LVAD recipients from May 2004 to May 2015 was pooled from the Mechanical Circulatory Support Research Network (MCSRN). Groups were assigned based on Age ≥ 70 (n = 163) and < 70 (n = 986). Results: Patients age ≥ 70 were more likely to be male (91%), have an ischemic cardiomyopathy (71%), atrial fibrillation (41%), hypertension (66%), diabetes (38%) and prior sternotomy (45%). Older patients also had a lower BMI and higher creatinine, 26.7 ± 0.4 v. 29.9 ± 0.5 and 1.46 ± 0.04 v. 1.35 ± 0.02, p < 0.05. The hazard ratio for mortality was highest in elderly patients in the early post-operative period and stabilized over time with no long-term differences in survival, p = 0.18, Figure 1a. Elderly patients had equivalent rates of device thrombosis and stroke, p = 0.47 and 0.44, Figures 1b-c. Survival free of gastrointestinal bleeding (GIB) at 1-year was 58% in elderly patients compared to 69% in younger patients, Figure 1d, p < 0.01. Multivariate cox regression revealed that age ≥ 70 was not a significant predictor of mortality (HR 0.93, 95% CI 0.69 - 1.25, p = 0.62), but pre-operative creatinine (HR 1.54, 95% CI 1.28 - 1.86, p < 0.01) and bilirubin (HR 1.2, 95% CI 1.03 - 1.4, p = 0.02) were. When age was considered a continuous variable, the HR was 1.2 (95% CI 1.07 - 1.3 per 10y, p < 0.01). Conclusions: Elderly patients, age ≥ 70, have equivalent long-term survival after LVAD implantation with similar rates of device thrombosis and stroke. Rates of GIB were higher in the elderly and this finding warrants caution when choosing anti-coagulation protocols in the elderly. Overall age ≥ 70 does not portend a poorer survival after LVAD implant.

Introduction: We compared outcome of repeat CABG (RCABG) and PCI in patients with previous CABG. Hypothesis: RCABG may improve survival versus PCI. Methods: From 1993 through 2009, 3,058 patients underwent revascularization after previous CABG. RCABG patients (n=530) were grouped by the use of arterial grafts (n=396), or saphenous vein grafts (SVG; n=134). At previous CABG, 37% of RCABG patients received IMA graft. PCI patients (n=2,528) were grouped into balloon angioplasty (BA; n=491), bare metal stent (BMS; n=1,267), and drug-eluting stent (DES; n=769). PCI patients were further stratified by the treated target into native coronary artery (n=1,637), bypass grafts (n=674), or both (n=216). Propensity score analysis matched 287 patients. Results: RCABG had increased 30-day mortality compared with PCI (HR=3.92; 95% CI, 2.25-6.84; P <.001) in multivariable analysis, while in propensity matched analysis it did not ( P =.09). Overall survival, however, was greater for RCABG compared with PCI in multivariable analysis (HR=0.70; 95% CI, 0.59-0.83; P <.001), as well as in propensity matched analysis (10-year survival rates were 52% vs 37%, respectively [ P =.005]). Compared with RCABG, PCI involving bypass grafts had increased mortality (HR, 1.39; 95% CI, 1.09-1.78; P =.008), whereas PCI targeting only the native coronaries did not (HR, 1.12; 95% CI, 0.85-1.47; P =.43); BMS patients had increased mortality (HR, 1.34; 95% CI, 1.06-1.68; P =.013), but DES did not (HR, 1.28; 95% CI, 0.77-2.12; P =.35). At RCABG, 318 patients (60%) received an IMA graft and late survival was similar to those receiving SVG; The use of IMA in previous CABG was associated with improved survival (HR=0.82; 95% CI, 0.72-0.92; P <.001]. Conclusions: Long-term survival after previous CABG is improved with RCABG compared to PCI, especially when PCI involves bypass grafts. There is no difference in long-term survival between RCABG using arterial grafts vs SVG only if IMA is used in either previous or RCABG.

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.

Introduction: Recent reports have documented an abrupt increase in 3-month confirmed HeartMate II left ventricular assist device (LVAD) thrombosis beginning in 2011 without a plateau observed to date. Because very little data exist from multi-institutional efforts, we report our experience. Methods: From January 2004 to December 2013, 516 pt underwent HeartMate II LVAD implant at three institutions (University of Michigan (n=254), Mayo Clinic Rochester (n=205), and Vanderbilt Heart and Vascular Institute (n=57)). Median age at implant was 60 yr (range, 18-82) and 428 (83%) were male. Confirmed pump thrombosis at 3 months was defined as thrombus found in the blood-contacting surfaces of the pump at the time of urgent transplant, device exchange or autopsy. Pt without at least 3 months of follow-up were excluded. Results: Confirmed pump thrombosis occurred in 9 pt within 3 months post implant. The incidence was greatest in the year 2012 (5.3%). Following this peak, the incidence of 3-month confirmed pump thrombosis decreased significantly to 2.9% (Figure). Significant differences in preoperative characteristics between patients with pump thrombosis and without thrombosis included female sex (36% vs. 16%, p=0.01), bridge to transplant (77% vs. 54%, p=0.03), atrial fibrillation (55% vs. 32%, p=0.04), and preop platelet count (231,000 vs. 172,000, p<0.001). Follow-up was available in all for a total of 857 patient years of support. At a median follow-up of 1.2 years (max., 9.8 years), a similar proportion of patients were alive (73% vs. 74%, p=0.9). Conclusions: We report a recent decrease in early, confirmed HeartMate II LVAD thrombosis to historically observed levels, which is disparate to recent reports. While we identified several differences in clinical characteristics between patient groups, the issue of pump thrombosis is complex and multifactorial. Most importantly, our findings demonstrate the need for more granular analyses from collaborative efforts.

Introduction: Frailty has recently been shown to be associated with increased risk of death after continuous-flow left ventricular assist device (CF-LVAD) implantation as destination therapy (DT), but no data exists specifically analyzing its association with specific early and late adverse events. Methods: Between February 2007 and May 2014, 251 patients (205 male) underwent primary implantation of CF-LVAD at our institution; 157 (63%) were implanted as DT and preoperative frailty assessment was available in 96 pt. Frailty was identified in 58/96 (60%) patients according to the deficit index (31 impairments, disabilities and comorbidities) and defined as > 25% deficits. Age (67 vs. 64 years, p=0.12), male sex (79% vs. 87%, 0.63), chronic kidney disease (64% vs. 63%, p=0.74), creatinine (1.7 vs. 1.5, p=0.1), hemoglobin (11.6 vs. 11.5, p=0.98), and albumin levels (3.7 vs. 3.8, p=0.53) were similar between frail and non-frail pt, while diabetes (59% vs. 13%, p<0.001), ischemic etiology (64% vs. 45%, p=0.04), and preop balloon pump (50% vs. 26%, p=0.01) were significantly different. Results: All patients underwent CF-LVAD implantation and cardiopulmonary bypass time was similar between groups (102 vs. 111 min., p=0.3). There were no significant differences in early adverse events between frail and non-frail pt, including inotrope duration (120 vs. 96 hr., p=0.11), right ventricular failure (19% vs. 13%, p=0.44), respiratory failure (26% vs. 18%, p=0.34), acute renal failure (16% vs. 13%, p=0.69), and hepatic dysfunction (16% vs. 13%, p=0.69). Median length of stay (20 vs. 16 days, p=0.25) and early mortality (12% vs. 8%, p=0.48) were also similar. During a median follow up of 2 years with 224 patient/years of support, any GI bleed (43% vs. 42%, p=0.79), any thromboembolic event (34% vs. 39%, p=0.74), and driveline infection (10% vs. 26%, p=0.052). Conclusions: In this select cohort of patients, frailty did not portend higher risk of adverse events after CF-LVAD implantation for DT despite prior observation that late survival is reduced in these patients. These findings are extremely important in patient selection and counseling of patients prior to LVAD implantation.