Delaying reperfusion plus left ventricular unloading reduces infarct size: Sub-analysis of DTU-STEMI pilot study

INTRODUCTION

The STEMI-DTU pilot study tested the early safety and practical feasibility of left ventricular (LV) unloading with a trans-valvular pump before reperfusion. In the intent-to-treat cohort, no difference was observed for microvascular obstruction (MVO) or infarct size (IS) normalized to either the area at risk (AAR) at 3-5 days or total LV mass (TLVM) at 3-5 days We now report a per protocol analysis of the STEMI-DTU pilot study.

METHODS

In STEMI-DTU STUDY 50 adult patients (25 in each arm) with anterior STEMI [sum of precordial ST-segment elevation (ΣSTE) ≥4 mm] requiring primary percutaneous coronary intervention (PCI) were enrolled. Only patients who met all inclusion and exclusion criteria were included in this analysis. Cardiac magnetic resonance (CMR) imaging 3-5 days after PCI quantified IS/AAR and IS/TLVM and MVO. Group differences were assessed using Student's t-tests and linear regression (SAS Version-9.4).

RESULTS

Of the 50 patients enrolled, 2 died before CMR imaging. Of the remaining 48 patients those without CMR at 3-5 days (n = 8), without PCI of a culprit left anterior descending artery lesion (n = 2), with OHCA (n = 1) and with ΣSTE < 4 mm (n = 5) were removed from this analysis leaving 32/50 (64 %) patients meeting all inclusion and exclusion criteria (U-IR, n = 15; U-DR, n = 17) as per protocol. Despite longer symptom-to-balloon times in the U-DR arm (228 ± 80 vs 174 ± 59 min, p < 0.01), IS/AAR was significantly lower with 30 min of delay to reperfusion in the presence of active LV unloading (47 ± 16 % vs 60 ± 15 %, p = 0.02) and remained lower irrespective of the magnitude of precordial ΣSTE. MVO was not significantly different between groups (1.5 ± 2.8 % vs 3.5 ± 4.8 %, p = 0.15). Among patients who received LV unloading within 180 min of symptom onset, IS/AAR was significantly lower in the U-DR group.

CONCLUSION

In this per-protocol analysis of the STEMI-DTU pilot study we observed that LV unloading for 30 min before reperfusion significantly reduced IS/AAR compared to LV unloading and immediate reperfusion, whereas in the ITT cohort no difference was observed between groups. This observation supports the design of the STEMI-DTU pivotal trial and suggests that strict adherence to the study protocol can significantly influence the outcome.

Extracorporeal membrane oxygenation as a bridge to durable left ventricular assist device implantation in INTERMACS-1 patients

Left ventricular assist devices (LVADs) are increasingly used as destination therapy or as a bridge to future cardiac transplant in patients with end-stage heart failure. Extracorporeal membrane oxygenation (ECMO) can be used to bridge patients in cardiogenic shock or with decompensated heart failure to durable mechanical circulatory support. We assessed outcomes in patients in critical cardiogenic shock (Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS] profile 1) who underwent implantation of a continuous-flow (CF)-LVAD, with or without preoperative ECMO bridging. For this retrospective study, we selected INTERMACS profile 1 patients who underwent CF-LVAD implantation at our institution between Sep 1, 2004 and Nov 30, 2018. Of 768 patients identified, 133 (17.3%) were INTERMACS profile 1; 26 (19.5%) received preoperative ECMO support, and 107 (80.5%) did not. Postimplantation outcomes were compared between the ECMO and no-ECMO groups. No significant differences were found in 30-day mortality (15.4 vs. 15.9%, P = 0.95) or survival at 1 year (53.8 vs. 60.9%, P = 0.51). Three patients who received ECMO before CF-LVAD implantation subsequently underwent cardiac transplant. In the ECMO group, the lactate level 1 day after ECMO initiation was lower in survivors than nonsurvivors (2.7 ± 2.2 vs. 7.4 ± 4.2 mmol/L, P = 0.02; area under the curve = 0.85, P = 0.01) after CF-LVAD implantation. Bridging with ECMO to CF-LVAD implantation in carefully selected INTERMACS profile 1 patients (those who are at the highest risk for critical cardiogenic shock and for whom palliation may be the only other option) produced acceptable postoperative outcomes.Field of research: Artificial lung/ECMO.

Role of thromboelastography in predicting and defining pump thrombosis in left ventricular assist device patients

INTRODUCTION

Optimal anticoagulation for left ventricular assist device recipients aims to balance thrombosis and bleeding complications. Routine plasma-based coagulation tests may not accurately reflect overall hemostasis, and surrogate markers are used to help guide clinicians in the diagnosis of pump thrombosis. Thromboelastography derived coagulation index (CI) has been shown to be a parameter that can reflect "normocoagulability" in mechanical circulatory support device patients, but there is minimal data with regard to outcomes available. Our aim was to determine the role of CI in predicting and defining suspected pump thrombosis in HeartMate II™ recipients.

MATERIALS AND METHODS

We performed a single center, retrospective longitudinal cohort study with a nested case-control analysis to compare serial CI values over time in adult HeartMate II™ recipients who had confirmed or suspected pump thrombosis to those who did not.

RESULTS AND CONCLUSIONS

A multivariate linear mixed model analysis of the suspected pump thrombosis versus no pump thrombosis groups found a significantly lower mean change in CI over time when recipients were followed for 24 months post-implant [0.71 (95% CI 0.1-1.32, p = .02)]; CI was first significant at six months. Within each arm, CI significantly decreased in the no pump thrombosis group, but did not significantly differ within the suspected pump thrombosis group. No significant differences were found between the two groups regarding the outcomes of death, transplant, or neurological events.

Clinical outcomes of inpatient cardiac rehabilitation for patients with treated left ventricular assist device in Korea: 1-year follow-up

In Korea, the first patient with a left ventricular assist device (LVAD) for destination therapy had successful implantation of a continuous-flow model in 2012. We investigated the safety and efficacy of exercise therapy with LVAD implantation 15 Korean patients. We retrospectively reviewed 15 patients (mean age, 67.4±11.6 years; 10 males, 5 female, left ventricular ejection fraction 23.6%±7.1%), including 4 with implanted continuous-flow and 11 an axial-flow LVAD. The New York Heart Association functional classification, ejection fraction, and quality of life were obtained. Survival rate, adverse events, admission rates, and enrollment rates in cardiac rehabilitation were investigated. Survival at 6 and 12 months was 100% and 89%, respectively. The New York Heart Association functional classification improved from 3.4±0.5 to 2.3±0.05 at 12 months postoperatively (P<0.0001). The ejection fraction significantly increased from 23.6%±7.2% on the preoperative day to 35.4%±14.2% at 1 year (P<0.0018). The quality of life was also improved at 1 year (P<0.0001). The most common adverse events were bleeding (56%) and dyspnea (44%). The number of admissions was 3.2 per patient-year. LVAD therapy is a safe and effective treatment option with exercise intervention for Korean patients waiting for heart transplantation or those who were ineligible for heart transplantation. A larger study with longer follow-up is needed to determine details clinical outcomes after LVAD.

Combined Endoscopic and Surgical Treatment of Severe Gastrointestinal Bleeding in a Patient with Heart Assist Device under Therapeutic Anticoagulation

Gastrointestinal (GI) bleeding is a common complication after heart assist device placement. Reasons for bleeding are multifactorial. Endoscopic therapy is the treatment of choice, whereas invasive procedures are avoided in these critically ill patients. We present the case of a 65-year-old male patient experiencing severe GI bleeding after left ventricular assist device (LVAD) and right ventricular assist device (RVAD) placement with therapeutic anticoagulation. Endoscopically, multiple gastric bleeding sources were found but could not be treated effectively due to a large blood clot. A combined endoscopic and surgical treatment was initiated, including gastrotomy for blood clot removal, surgical transgastric suturing, endoscopic over-the-scope clip (OTSC) placement and hemospray application. Postoperative endoscopic visualization showed effective bleeding control. The patient unfortunately died due to causes unrelated to the treatment. This case shows that a minimal invasive combination of endoscopic and surgical techniques can be an alternative treatment for severe upper GI bleeding in critically ill and anticoagulated patients.

[Rehabilitation standards for follow-up treatment and rehabilitation of patients with ventricular assist device (VAD)]

The increasing use of ventricular assist devices (VADs) in terminal heart failure patients provides new challenges to cardiac rehabilitation physicians. Structured cardiac rehabilitation strategies are still poorly implemented for this special patient group. Clear guidance and more evidence for optimal modalities are needed. Thereby, attention has to be paid to specific aspects, such as psychological and social support and education (e.g., device management, INR self-management, drive-line care, and medication).In Germany, the post-implant treatment and rehabilitation of VAD Patients working group was founded in 2012. This working group has developed clear recommendations for the rehabilitation of VAD patients according to the available literature. All facets of VAD patients' rehabilitation are covered. The present paper is unique in Europe and represents a milestone to overcome the heterogeneity of VAD patient rehabilitation.

[End-of-life decisions and practices in critically ill patients in the cardiac intensive care unit. A nationwide survey]

BACKGROUND

Ethical and medical criteria in the decision-making process of withholding or withdrawal of life support therapy in critically ill patients present a great challenge in intensive care medicine.

OBJECTIVES

The purpose of this work was to assess medical and ethical criteria that influence the decision-making process for changing the aim of therapy in critically ill cardiac surgery patients.

MATERIALS AND METHODS

A questionnaire was distributed to all German cardiac surgery centers (n = 79). All clinical directors, intensive care unit (ICU) consultants and ICU head nurses were asked to complete questionnaires (n = 237).

RESULTS

In all, 86 of 237 (36.3 %) questionnaires were returned. Medical reasons which influence the decision-making process for changing the aim of therapy were cranial computed tomography (cCT) with poor prognosis (91.9 %), multi-organ failure (70.9 %), and failure of assist device therapy (69.8 %). Concerning ethical reasons, poor expected quality of life (48.8 %) and the presumed patient's wishes (40.7 %) were reported. There was a significant difference regarding the perception of the three different professional groups concerning medical and ethical criteria as well as the involvement in the decision-making process.

CONCLUSION

In critically ill cardiac surgery patients, medical reasons which influence the decision-making process for changing the aim of therapy included cCT with poor prognosis, multi-organ failure, and failure of assist device therapy. Further studies are mandatory in order to be able to provide adequate answers to this difficult topic.

A monitoring and physiological control system for determining aortic valve closing with a ventricular assist device

OBJECTIVES

Real-time monitoring of the aortic valve function and the loading state of the left ventricle (LV) during mechanical circulatory support is essential. Therefore, we developed a system that determines accurately the aortic valve closing moment based on integrals derived from the pump inlet pressure and the pump power [pressure-power area (PPA)].

METHODS

A Deltastream diagonal pump was implanted in 10 healthy Rhoen sheep. Changes in ventricular volume and pressure in different assist levels were measured by a conductance catheter placed in the LV and were correlated with intrinsic pump signals, motor power, voltage and current. Measurements were obtained in the state of normal as well as decreased left ventricular contractility induced by β-blockers.

RESULTS

Complete datasets were obtained in seven animals. The PPA-feedback signal reached its maximum at the speed of aortic valve closing. This was validated by pressure-volume (PV)-catheter measurements both at the baseline and in the state of decreased contractility. In both cases, zero-crossing occurred at the point of aortic valve closing speed.

CONCLUSIONS

With this trial, we deliver the experimental basis for the development of an automatic feedback controller that would allow periodic speed changes in accordance with the loading state of the native ventricle and the opening state of the aortic valve. This would deliver real-time data to treating physicians and enable the establishment of a standard weaning protocol.

Can the temporary use of right ventricular assist devices bridge patients with acute right ventricular failure after cardiac surgery to recovery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: Can the temporary use of right ventricular assist devices (RVADs) bridge patients to recovery who suffer acute right ventricular failure after cardiac surgery? More than 183 papers were found using the reported search, of which 13 represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Indications for surgical intervention included coronary artery bypass surgery, valve replacement, post-heart transplant and left ventricular assist device insertion. Significant reductions in central venous pressure (P = 0.005) and mean pulmonary artery pressures (P < 0.01) were reported during and after RVAD support. Furthermore, increases in right ventricular cardiac output (P < 0.05), right ventricular ejection fraction (P < 0.05), right ventricular stroke work (P < 0.05) and pulmonary artery oxygen saturations (P < 0.05) were also seen. Assessment by one study showed that on Day 7 after RVAD removal, the right ventricular ejection fraction had increased by up to 40%. Dynamic echocardiography studies performed before, during and after RVAD placement demonstrated that after RVAD implantation, right ventricular end-diastolic dimensions (P < 0.05) and right atrial dimensions decreased (P < 0.05) and right ventricular ejection fraction (P < 0.05) increased. Although several studies successfully weaned patients from an RVAD, there were several complications, including bleeding requiring surgical intervention. However, this may be reduced by using percutaneous implantation (bleeding incidence: 4 of 9 patients) rather than by a surgically implanted RVAD (bleeding incidence: 5 of 5 patients). However, mortality is higher in percutaneous RVAD patients rather than in surgical RVAD (80-44%) patients. Causes of death cited for patients on an RVAD included multiorgan failure, sepsis, thromboembolic events, reoccurring right heart failure and failure to wean due to persistent right ventricular failure. We conclude that RVADs have been successfully used to bridge patients to recovery after cardiac surgery; however, RVADs carry numerous risks and a high mortality rate.