Stulak, John M.

Background: Extracorporeal membrane oxygenation (ECMO) is increasingly used in acute myocardial infarction (AMI); however, there are limited large-scale national data. Methods: Using the National Inpatient Sample database from 2000 to 2014, a retrospective cohort of AMI utilizing ECMO was identified. Use of percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous left ventricular assist device (LVAD) was also identified in this population. Outcomes of interest included temporal trends in utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD), in-hospital mortality, and resource utilization. Results: In ≈9 million AMI admissions, ECMO was used in 2962 (<0.01%) and implanted a median of 1 day after admission. ECMO was used in 0.5% and 0.3% AMI admissions complicated by cardiogenic shock and cardiac arrest, respectively. ECMO was used more commonly in admissions that were younger, nonwhite, and with less comorbidity. ECMO use was 11× higher in 2014 as compared with 2000 (odds ratio, 11.37 [95% CI, 7.20–17.97]). Same-day percutaneous coronary intervention was performed in 23.1%; intra-aortic balloon pump/percutaneous LVAD was used in 57.9%, of which 30.3% were placed concomitantly. In-hospital mortality with ECMO was 59.2% overall but decreased from 100% (2000) to 45.1% (2014). Durable LVAD and cardiac transplantation were performed in 11.7% as an exit strategy. Of the hospital survivors, 40.8% were discharged to skilled nursing facilities. Older age, male sex, nonwhite race, and lower socioeconomic status were independently associated with higher in-hospital mortality with ECMO use. Conclusions: In AMI admissions, a steady increase was noted in the utilization of ECMO alone and with concomitant procedures (percutaneous coronary intervention, intra-aortic balloon pump, and percutaneous LVAD). In-hospital mortality remained high in AMI admissions treated with ECMO.

Background The presence of a durable left ventricular assist device ( LVAD ) is associated with increased risk of vasoplegia in the early postoperative period following heart transplantation ( HT ). However, preoperative predictors of vasoplegia and its impact on survival after HT are unknown. We sought to examine predictors and outcomes of patients who develop vasoplegia after HT following bridging therapy with an LVAD . Methods and Results We identified 94 patients who underwent HT after bridging with continuous‐flow LVAD from 2008 to 2018 at a single institution. Vasoplegia was defined as persistent low vascular resistance requiring ≥2 intravenous vasopressors within 48 hours after HT for >24 hours to maintain mean arterial pressure >70 mm Hg. Overall, 44 patients (46.8%) developed vasoplegia after HT . Patients with and without vasoplegia had similar preoperative LVAD , echocardiographic, and hemodynamic parameters. Patients with vasoplegia were significantly older; had longer LVAD support, higher preoperative creatinine, longer cardiopulmonary bypass time, and higher Charlson comorbidity index; and more often underwent combined organ transplantation. In a multivariate logistic regression model, older age (odds ratio: 1.08 per year; P =0.010), longer LVAD support (odds ratio: 1.06 per month; P =0.007), higher creatinine (odds ratio: 3.9 per 1 mg/dL; P =0.039), and longer cardiopulmonary bypass time (odds ratio: 1.83 per hour; P =0.044) were independent predictors of vasoplegia. After mean follow‐up of 4.0 years after HT , vasoplegia was associated with increased risk of all‐cause mortality (hazard ratio: 5.20; 95% CI, 1.71–19.28; P =0.003). Conclusions Older age, longer LVAD support, impaired renal function, and prolonged intraoperative CPB time are independent predictors of vasoplegia in patients undergoing HT after LVAD bridging. Vasoplegia is associated with worse prognosis; therefore, detailed assessment of these predictors can be clinically important.

Following implantation of continuous-flow left ventricular assist devices, mechanical off-loading results in improved resting hemodynamics; however, peak exercise capacity generally does not increase substantially. This study evaluated patients supported by continuous-flow left ventricular assist devices who were invasively monitored during exercise to define parameters that underpin exercise capacity and outcomes. A review of all patients supported by continuous-flow left ventricular assist devices who underwent supine bicycle ergometry exercise testing with measurement of pulmonary gas exchange during right heart catheterization for evaluation of dyspnea at one institution between 2007 and 2018 was performed (n = 22). The primary outcome of this investigation was death or heart failure hospitalization. Although resting filling pressures were relatively preserved, resting cardiac index (Fick) was low (2.1 ± 0.5 mL/kg/min). An impaired cardiac output reserve was present in 75% of patients. On univariate modeling, patients with supine exercise–induced hypoxemia (O 2 saturation <90%) experienced significantly diminished hospitalization-free survival (unadjusted hazard ratio = 11.0, confidence interval = 2.4–57.2, p = 0.003), which persisted despite adjustment for right heart catheterization peak VO 2 and peak cardiac output (adjusted hazard ratio = 25, confidence interval = 3.6–322, p = 0.001). Our findings suggest that supine exercise testing provides additional prognostic utility in the continuous-flow left ventricular assist device population.

Antithrombotic optimization with a glycoprotein IIb/IIIa inhibitor has been used for the treatment of suspected pump thrombosis, but available literature with tirofiban is lacking. This study aims to describe the use of tirofiban for suspected pump thrombosis. This was a single-center cohort study of left ventricular assist device patients who received tirofiban for the treatment of suspected pump thrombosis from January 1, 2016 to July 31, 2017. Tirofiban was initiated at 0.1 μg/kg/min in patients with normal renal function and subsequent dose adjustments for altered renal function or history of bleeding were employed. Success was defined as resolution of lactate dehydrogenase back to patients’ known baseline. Fourteen patients were included for 16 total instances of tirofiban use during the time period. Tirofiban was continued for a median of 5 days (range: 0.3–35 days). Successful treatment was achieved in 12 of the 16 tirofiban uses (75%). Seven bleeding events occurred while on therapy, two major and five minor. This study showed a majority of patients achieved success with tirofiban for suspected pump thrombosis. For patients who are not current candidates for pump exchange or transplant, tirofiban may be considered a therapeutic medical management option.

Background Diastolic pulmonary gradient ( DPG ) was proposed as a better marker of pulmonary vascular remodeling compared with pulmonary vascular resistance ( PVR ) and transpulmonary gradient ( TPG ). The prognostic significance of DPG in patients requiring a left ventricular assist device ( LVAD ) remains unclear. We sought to investigate whether pre‐ LVAD DPG is a predictor of survival or right ventricular ( RV ) failure post‐ LVAD . Methods and Results We retrospectively reviewed 268 patients who underwent right heart catheterization before LVAD implantation from 2007 to 2017 and had pulmonary hypertension because of left heart disease. Patients were dichotomized using DPG ≥7 mm Hg, PVR ≥3 mm Hg, or TPG ≥12 mm Hg. The associations between these parameters and all‐cause mortality or RV failure post LVAD were assessed with Cox proportional hazards regression and Kaplan–Meier analyses. After a mean follow‐up time of 35 months, elevated DPG was associated with increased risk of RV failure (hazard ratio [ HR ]: 3.30; P =0.004, for DPG ≥7 versus DPG <7), whereas elevated PVR ( HR 1.85, P =0.13 for PVR ≥3 versus PVR <3) or TPG ( HR 1.47, P =0.35, for TPG ≥12 versus TPG <12) were not associated with the development of RV failure. Elevated DPG was not associated with mortality risk ( HR 1.16, P =0.54, for DPG ≥7 versus DPG <7), whereas elevated PVR , but not TPG , was associated with higher mortality risk ( HR 1.55; P =0.026, for PVR ≥3 versus PVR <3). Conclusions Among patients with pulmonary hypertension because of left heart disease requiring LVAD support, elevated DPG was associated with RV failure but not survival, while elevated PVR predicted mortality post LVAD implantation.

Introduction: Long-term use of continuous-flow left ventricular assist devices may have negative consequences for autonomic, cardiovascular and gastrointestinal function. It has thus been suggested that non-invasive monitoring of arterial pulsatility in patients with a left ventricular assist device is highly important for ensuring patient safety and longevity. We have developed a novel, semi-automated frequency-domain-based index of arterial pulsatility that is obtained during suprasystolic occlusions of the upper arm: the ‘cuff pulsatility index’. Purpose: The purpose of this study was to evaluate the relationship between the cuff pulsatility index and invasively determined arterial pulsatility in patients with a left ventricular assist device. Methods: Twenty-three patients with a left ventricular assist device with end-stage heart failure (six females: age = 65 ± 9 years; body mass index = 30.5 ± 3.7 kg m −2 ) were recruited for this study. Suprasystolic occlusions were performed on the upper arm of the patient’s dominant side, from which the cuff pressure waveform was obtained. Arterial blood pressure was obtained from the radial artery on the contralateral arm. Measurements were obtained in triplicate. The relationship between the cuff pressure and arterial blood pressure waveforms was assessed in the frequency-domain using coherence analysis. A mixed-effects approach was used to assess the relationship between cuff pulsatility index and invasively determined arterial pulsatility (i.e. pulse pressure). Results: The cuff pressure and arterial blood pressure waveforms demonstrated a high coherence up to the fifth harmonic of the cardiac frequency (heart rate). The cuff pulsatility index accurately tracked changes in arterial pulse pressure within a given patient across repeated measurements. Conclusions: The cuff pulsatility index shows promise as a non-invasive index for monitoring residual arterial pulsatility in patients with a left ventricular assist device across time.

There are contrasting data on concomitant Impella device in cardiogenic shock patients treated with venoarterial extracorporeal membrane oxygenation (VA ECMO) (ECPELLA). This study sought to compare early mortality in patients with cardiogenic shock treated with ECPELLA in comparison to VA ECMO alone. We reviewed the published literature from 2000 to 2018 for randomized, cohort, case-control, and case series studies evaluating adult patients requiring VA ECMO for cardiogenic shock. Five retrospective observational studies, representing 425 patients, were included. Venoarterial extracorporeal membrane oxygenation with concomitant Impella strategy was used in 27% of the patients. Median age across studies varied between 51 and 63 years with 59–88% patients being male. Use of ECPELLA was associated with higher weaning from VA ECMO and bridging to permanent ventricular assist device or cardiac transplant in three and four studies, respectively. The studies showed moderate heterogeneity with possible publication bias. The two studies that accounted for differences in baseline characteristics between treatment groups reported lower 30 day mortality with ECPELLA versus VA ECMO. The remaining three studies did not adjust for potential confounding and were at high risk for selection bias. In conclusion, ECPELLA is being increasingly used as a strategy in patients with cardiogenic shock. Additional large, high-quality studies are needed to evaluate clinical outcomes with ECPELLA.

Objective This study aimed to identify characteristics, spectrum of tricuspid regurgitation (TR) severity and treatment patterns in patients considered for intervention of severe TR at a tertiary centre. The population being considered for TR intervention is currently not well defined and the role of transcatheter interventions is unclear. Methods The study involved 87 patients with severe TR considered for intervention from 1 March 2016 to 12 November 2018 at Mayo Clinic. Patients receiving medications alone were compared with those receiving intervention to identify patterns in demographics, clinical/echocardiographic associations and survival. Results Mean age was 80±9 (56% female), 93% had atrial fibrillation and 64% had chronic kidney disease ≥3 a. Follow-up was 331±276 days; 95% were symptomatic with 6 min walk distance of 270±110 m. Loop diuretics were used in 93%; aldosterone antagonists in 35%. Mean tricuspid annular plane systolic excursion was 15.6±3.8 mm, effective regurgitant orifice area (EROA) 82±32 mm2 and stroke volume index 39±11 mL/m2; 48% had at least moderate right ventricular (RV) dysfunction, and 75% did not undergo intervention. Patients receiving intervention showed trends towards larger EROA (93±33 vs 75±31 mm2), better right ventricular function and more severe symptoms. Overall group 30-day and 1-year survival were 100% and 76%, respectively. Conclusions Patients with severe TR considered for intervention are commonly elderly with atrial fibrillation, advanced TR and RV dysfunction; 75% were treated with medications alone and not offered intervention. Patients with greater EROA, better RV function and more severe symptoms were more likely to receive intervention. These findings have implications for future trial design.

Abstract OBJECTIVES Limited literature is available on the best management strategy for tricuspid valve (TV) disease in adults. We sought to review our long-term outcomes of TV surgery with regard to survival and reoperation. METHODS A retrospective analysis of all patients ≥18 years of age [n = 2541, aged 67 ± 13years, 1433 (56%) females] who underwent first-time TV surgery between January 1993 and December 2013 was done. There were 1735 patients who received TV repair and 806 patients underwent replacement. A gradient boosting machine model was used to derive a propensity score for predicting replacement using 27 preoperative characteristics. Four hundred and eighteen propensity-matched pairs of TV repair and replacement were identified. Cox proportional hazard regression was used on the matched subset to determine the effect of replacement. RESULTS Functional TV regurgitation was present in 54% (n = 1369). A bioprosthesis was used in 84% (n = 680) of replacements, while 54% (n = 934) of TV repairs were ring annuloplasties. Operative mortality was 8% (n = 212). Overall survival was 54%, 29% and 13% at 5, 10 and 15 years, respectively. After propensity score matching, replacement was significantly associated with increased mortality [hazard ratio (HR) 1.54, 95% confidence interval (CI) 1.18–2.00; P = 0.001]. The cumulative incidence of TV reoperation was similar between the 2 groups when accounting for the competing risk of death [Fine–Gray HR 1.56, 95% CI 0.9–2.8; P = 0.144]. CONCLUSIONS TV surgery is associated with poor outcomes due to multiple patient comorbidities. TV repair results in better survival compared to replacement in patients with similar comorbidities with no increased risk of getting a reoperation.

Background Left ventricular (LV) hemodynamic assessment has been sparsely performed in patients supported on continuous‐flow LV assist devices (cf LVADs ). Insight into dynamic changes of left heart parameters during ramp studies may improve LV assist device optimization and evaluate pathology. Methods and Results To complement right heart catheterization, a novel technique for left heart catheterization in patients with a cf LVAD was developed. Patients implanted with cf LVAD s underwent hemodynamic ramp left heart catheterization and right heart catheterization with transthoracic echocardiography. Continuous aortic and LV pressures were measured along with right atrial, pulmonary artery, and pulmonary capillary wedge pressures. A novel index, the transaortic gradient ( TAG ) was established. Thirty eight patients with cf LVADs were evaluated at a median of 446 days (interquartile range, 183–742) after device implant. During left heart catheterization performed for hemodynamic optimization, drop‐in LV end‐diastolic pressure and pulmonary capillary wedge pressure were associated with a rise in TAG . A range was identified for TAG (20–40 mm Hg) as providing the most optimal level of hemodynamic offloading. Pathologic states deviated from normal responses to ramp. LV assist device thrombosis was associated with an inability to increase in TAG during speed ramp. Significant aortic insufficiency was associated with a marked increase in LV end‐diastolic pressure despite a concomitant decrease in pulmonary capillary wedge pressure with increasing LV assist device speeds. Conclusions Inclusion of left heart catheterization to a typical right heart catheterization LV assist device ramp protocol imparted unique insights to optimize cf LVAD speeds in different clinical scenarios. A novel index, the TAG was defined and provided additional resolution to optimized offloading.