Single center first year experience and outcomes with Impella 5.5 left ventricular assist device

Use of Cervical Approach for Insertion of the Impella 5.5 Ventricular Assist Device (Abiomed) in Pediatric Patients: Cohort Study

BackgroundImpella 5.5 ventricular assist device (VAD) insertion is typically done via the axillary artery or directly through the aorta; however, an axillary artery must be ≥6 mm in diameter, which excludes many pediatric patients who do not meet this criterion. The innominate artery is a larger vessel that can better accommodate the Impella VAD in pediatric patients. Outcomes of this technique were compared with other pediatric patients undergoing the standard axillary artery cannulation.MethodsThe Heart Center at Le Bonheur Children's Hospital recently adopted the trans-innominate cervical approach for insertion of the Impella 5.5 VAD. We performed a retrospective cohort study comparing these cases to data collected from cases using an axillary approach found in the Advanced Cardiac Therapies Improving Outcomes Network database. Comparisons between preoperative characteristics, postoperative course, adverse events, anticoagulation, and clinical outcomes for these two groups were analyzed.ResultsThirty-nine patients were implanted via the axillary approach; seven patients were implanted via the transinnominate cervical approach at our institution. Patients inserted via the trans-innominate approach had fewer days on the device (median, 8 [range, 3-24]), postimplant intensive care unit days (16 [3-24]), and hospital length of stay (14 [3-28]) compared with axillary insertion patients (12.5 [6.75-29.2], 58.5 [12.5-43.5], and 32 [19.7-83.5], respectively). Trans-innominate patients had fewer adverse events than axillary patients.ConclusionsTrans-innominate cervical approach for insertion of the Impella 5.5 VAD is safe with low rates of adverse events in pediatric patients. As miniaturization of VAD therapy continues to evolve, this technique may provide greater application of these devices for even smaller children.

Induction therapy confers survival advantage in mechanically supported patients regardless of peak CPRA in heart transplantation

Background

There is no consensus regarding induction therapy in patients on mechanically circulatory support (MCS) listed for heart transplantation. We sought to elucidate differences in outcomes between no induction and induction.

Methods

A total of 3,987 patients were analyzed from the UNOS database from January 2018 through December 2022. Patients on Extracorporeal Membrane Oxygenation (ECMO), HeartMate 3, Impella 5.0 or 5.5, and intra-aortic balloon pump (IABP) and receiving no induction, anti-IL2R antibodies, or T cell depleting agent (TCDA) were included.

Results

Of 3,987 patients, 1,288 (32.3%) received no induction, 1,566 (39.3%) received anti-IL2R antibodies, and 1,133 (28.4%) received TCDA. A total of 1,895 (47.5%) were supported with IABP; 1,098 (27.5%) with HeartMate 3; 489 (12.3%) with Impella 5.0 or 5.5; 351 (8.8%) with ECMO; and 154 (3.9%) with combination of the above devices. Comparison of 1-year survival between no induction, anti-IL2R, and TCDA groups in all MCS patients revealed significantly worse survival among those receiving no induction (p<0.0001). Subgroup analysis of peak CPRA 0% patients revealed that no induction had significantly worse survival at 1 year (p=0.002). Analysis of acute rejection at 1 year showed a significantly decreased number of rejection episodes in the TCDA group compared to no induction (OR 0.65, CI 0.47-0.88, p=0.006).

Conclusions

Patients requiring MCS prior to heart transplantation have significantly improved post-transplant survival with induction therapy, regardless of their peak CPRA. TCDA confers decreased number of acute rejection episodes at 1 year in this patient population.

Acute Hemodynamic and Echocardiographic Consequences of Impella 5.5 Placement in Patients With Advanced Cardiogenic Shock

We sought to investigate the hemodynamic and echocardiographic consequences of the Impella 5.5 during the acute perioperative period. A retrospective analysis of patients who underwent device implantation at our institution between January 2021 and June 2023 was performed. Hemodynamic and echocardiographic changes were modeled as linear mixed models with random intercepts for patient and fixed as well as random effects of time. Of 87 patients identified, most were male (72, 83%) with nonischemic cardiomyopathy (44, 51%). In the first two postoperative days, the median cardiac output increased by 1.2 L/min (p < 0.05), although the median Impella flow remained at 4.1 L/min. Mean pulmonary artery pressures (32 vs. 27 mm Hg, p < 0.05) and vasoactive inotrope scores (5.6 vs. 3.7, p < 0.01) were modestly reduced. Significant echocardiographic improvement was noted in 61% and 71% of patients with significant preoperative mitral or tricuspid regurgitation, respectively. However, no changes in ejection fraction, left ventricle (LV) diameter, or right ventricular function were noted (all p > 0.05). At 30 days, 27 (31%) patients were transplanted and 13 (15%) were bridged to a durable left ventricular assist device (LVAD). We conclude that in the acute phase following Impella implantation, LV offloading, reductions in pulmonary artery pressures, and improvement in valvular regurgitation are seen without changes to ventricular geometry.

Are there etiology-specific risk factors for adverse outcomes in patients on Impella 5.5 support?

Objectives

To identify possible etiology-specific differences in preoperative risk factors for major adverse events during Impella 5.5 support in patients with ischemic (ICM) and nonischemic cardiomyopathy (NICM).

Methods

From October 2019 to January 2023, 228 Impella 5.5 devices were inserted at our institution. Patients were stratified into ICM (n = 124) and NICM (n = 104) cohorts. The primary outcome was a composite of death/stroke/new-onset dialysis while actively receiving Impella 5.5 support. Random forests identified preoperative factors predictive of the primary outcome separately for each cohort, with ranking by variable importance.

Results

The primary outcome occurred in 42 (34%) patients with ICM and 35 (34%) patients with NICM. Twenty-one (17%) patients with ICM and 21 (20%) patients with NICM died on Impella 5.5; stroke occurred in 12 (9.7%) patients with ICM and 3 (2.9%) patients with NICM, and new-onset dialysis was initiated in 23 (19%) patients with ICM and 24 (23%) patients with NICM while actively receiving Impella 5.5 support. Risk factors reflecting systemic and myocardial cellular injury, end-organ and cardiopulmonary failure, right ventricular dysfunction, and smaller left ventricular dimensions were most predictive of adverse outcomes in both cohorts. Indications for Impella 5.5 and device strategy (bridge to recovery, advanced therapies, or decision) were not top risk factors in either cohort.

Conclusions

Risk factors related to preoperative stability, right ventricular dysfunction, and left ventricular size were more predictive of adverse outcomes while actively receiving Impella 5.5 support than indication or device strategy. These factors could help identify high-risk patients who may benefit from additional tailored management to reduce their risk for these impactful adverse outcomes while on Impella 5.5 support.

Impella 5.5: A Systematic Review of the Current Literature

OBJECTIVE

Impella 5.5 (Abiomed, Danvers, MA, USA) is a temporary mechanical circulatory support device used for patients in cardiogenic shock. This review provides a comprehensive overview of the device's clinical effectiveness, safety profile, patient outcomes, and relevant procedural considerations.

METHODS

We conducted a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines using the PubMed/MEDLINE database. The search query included articles available from October 6, 2022, through January 13, 2023. Our initial search identified 75 studies. All records were screened by 2 independent reviewers using the Covidence software for adherence to our inclusion criteria, and 8 retrospective cohort studies were identified as appropriate for inclusion.

RESULTS

Across the included studies, the sample size ranged from 4 to 275, with predominantly male cohorts. Indications for Impella support varied, and the duration of support ranged from 9.8 to 70 days. Overall, Impella support appeared to be associated with favorable survival rates and manageable complications in various patient populations. Complications associated with Impella use included bleeding, stroke, and device malfunctions. Two studies compared prolonged and Food and Drug Administration-approved Impella support, showing similar outcomes and adverse events.

CONCLUSIONS

Impella 5.5 continues to be an attractive option for bridging patients to definitive therapy. Survival during and after Impella 5.5 was favorable for patients regardless of initial indication. However, device use was associated with several important complications, which calls for judicious use and a precontemplated exit strategy. Limitations of this literature review include biases inherent to the retrospective studies included, such as selection and publication bias.

Patient Characteristics and Early Clinical Outcomes With Impella 5.5: A Systematic Review and Meta-Analysis

Data regarding outcomes with Impella 5.5 are limited. The aim of this systematic review and meta-analysis was to summarize patient and treatment characteristics and early clinical outcomes among patients supported by Impella 5.5. A systematic literature search was conducted in PubMed, Scopus, and Cochrane databases from September 2019 to March 2023. Studies reporting outcomes in greater than or equal to 5 patients were included for review. Patient characteristics, treatment characteristics, and early clinical outcomes were extracted. Outcomes included adverse events, survival to hospital discharge, and 30 day survival. Random-effect models were used to estimate pooled effects for survival outcomes. Assessment for bias was performed using funnel plots and Egger's tests. Fifteen studies were included for qualitative review, representing 707 patients. Mean duration of support was 9.9 ± 8.2 days. On meta-analysis of 13 studies reporting survival outcomes, survival to hospital discharge was 68% (95% confidence interval [CI], 58-78%), and 30 day survival was 65% (95% CI, 56-74%) among patients with Impella devices predominantly supported by Impella 5.5 (>60%). There was significant study heterogeneity for these outcomes. Among 294 patients with Impella 5.5 only, survival to discharge was 78% (95% CI, 72-82%) with no significant study heterogeneity. This data present early benchmarks for outcomes with Impella 5.5 as clinical experience with these devices accrues.

Association between Impella device support and elevated rates of gout flares: a retrospective propensity-matched study

BACKGROUND

Impella is an advanced ventricular assist device frequently used as a bridge to heart transplantation. The association of Impella with increased rates of gout flares has not been studied. Our primary aim is to determine the rates of gout flares in patients on Impella support.

METHODOLOGY

A retrospective study was conducted between January 2017 and September 2022 involving all patients who underwent heart transplantation. The cohort was divided into two groups based on Impella support for statistical analysis. In patients receiving Impella support, outcome measures were compared based on the development of gout flares. 1:1 nearest neighbor propensity match, as well as inverse propensity of treatment weighted analyses, were performed to explore the causal relationship between impella use and gout flare in our study population.

RESULTS

Our analysis included 213 patients, among which 42 (19.71%) patients were supported by Impella. Impella and non-Impella groups had similar age, race, and BMI, but more males were in the Impella group. Gout and chronic kidney disease were more prevalent in Impella-supported patients, while coronary artery disease was less common. The prevalence of gout flare was significantly higher in Impella patients (30.9% vs. 5.3%). 42 Impella-supported patients were matched with 42 patients from the non-impella group upon performing a 1:1 propensity matching. Impella-supported patients were noted to have a significantly higher risk of gout flare (30.9% vs. 7.1%, SMD = 0.636), despite no significant difference in pre-existing gout history and use of anti-gout medications. Impella use was associated with a significantly increased risk of gout flare in unadjusted (OR 8.07), propensity-matched (OR 5.83), and the inverse propensity of treatment-weighted analysis (OR 4.21).

CONCLUSION

Our study is the first to identify the potential association between Impella support and increased rates of gout flares in hospitalized patients. Future studies are required to confirm this association and further elucidate the biological pathways. It is imperative to consider introducing appropriate measures to prevent and promptly manage gout flares in Impella-supported patients.

Surgically implanted endovascular, microaxial left ventricular assist device: A single institution study

Objective

The Impella 5.5 (Abiomed, Inc), a surgically implanted endovascular microaxial left ventricular assist device, is increasingly used worldwide and there have been more than 10,000 implants. The purpose of this study is to describe a large-volume, single-center experience with the use of the Impella 5.5.

Methods

Data were obtained retrospectively from patients supported with the Impella 5.5 implanted at our institution from May 1, 2020, to December 31, 2022. Demographic, operative, and postoperative outcomes for each group are described. Results are reported in median (interquartile range) or n (%). The entire cohort was divided into 5 main groups based on the intention to treat at the time of the Impella 5.5 implantation: (1) patients who had a planned Impella 5.5 implanted at the time of high-risk cardiac surgery; (2) patients with cardiogenic shock; (3) patients bridged to a durable left ventricular assist device; (4) patients bridged to transplant; and (5) patients with postcardiotomy shock who received an unplanned Impella 5.5 implant.

Results

A total of 126 patients were supported with the Impella 5.5. Overall survival to device explant was 76.2%, with 67.5% surviving to discharge. Midterm survival was assessed with a median follow-up time of 318 days and demonstrated an overall survival of 60.3% and a median of 650 days (549-752).

Conclusions

Outcomes after using the Impella 5.5 are variable depending on the indication of use. Patient selection may be of utmost importance and requires further experience with this device to determine who will benefit from insertion.

Temporary mechanical circulatory support & enhancing recovery after cardiac surgery

PURPOSE OF REVIEW

This review highlights the integration of enhanced recovery principles with temporary mechanical circulatory support associated with adult cardiac surgery.

RECENT FINDINGS

Enhanced recovery elements and efforts have been associated with improvements in quality and value. Temporary mechanical circulatory support technologies have been successfully employed, improved, and the value of their proactive use to maintain hemodynamic goals and preserve long-term myocardial function is accruing.

SUMMARY

Temporary mechanical circulatory support devices promise to enhance recovery by mitigating the risk of complications, such as postcardiotomy cardiogenic shock, organ dysfunction, and death, associated with adult cardiac surgery.

The Year in Cardiothoracic and Vascular Anesthesia: Selected Highlights From 2023

This special article is the 16th in an annual series for the Journal of Cardiothoracic and Vascular Anesthesia. The authors thank the editor-in-chief, Dr. Kaplan, and the editorial board for the opportunity to continue this series, namely the research highlights of the past year in the specialty of cardiothoracic and vascular anesthesiology. The major themes selected for 2023 are outlined in this introduction, and each highlight is reviewed in detail in the main article. The literature highlights in the specialty for 2023 begin with an update on perioperative rehabilitation in cardiothoracic surgery, with a focus on novel methods to best assess patients in the preoperative and postoperative periods, and the impact of rehabilitation on outcomes. The second major theme is focused on cardiac surgery, with the authors discussing new insights into inhaled pulmonary vasodilators, coronary revascularization surgery, and discussion of causes of coronary graft failure after surgery. The third theme is focused on cardiothoracic transplantation, with discussions focusing on bridge-to-transplantation strategies. The fourth theme is focused on mechanical circulatory support, with discussions focusing on both temporary and durable support. The fifth and final theme is an update on medical cardiology, with a focus on outcomes of invasive approaches to heart disease. The themes selected for this article are only a few of the diverse advances in the specialty during 2023. These highlights will inform the reader of key updates on various topics, leading to improved perioperative outcomes for patients with cardiothoracic and vascular disease.

Cardiogenic shock etiology and exit strategy impact survival in patients with Impella 5.5

BACKGROUND

Despite historical differences in cardiogenic shock (CS) outcomes by etiology, outcomes by CS etiology have yet to be described in patients supported by temporary mechanical circulatory support (MCS) with Impella 5.5.

OBJECTIVES

This study aims to identify differences in survival and post-support destination for these patients in acute myocardial infarction (AMI) and acute decompensated heart failure (ADHF) CS at a high-volume, tertiary, transplant center.

METHODS

A retrospective review of patients who received Impella 5.5 at our center from November 2020 to June 2022 was conducted.

RESULTS

Sixty-seven patients underwent Impella 5.5 implantation for CS; 23 (34%) for AMI and 44 (66%) for ADHF. AMI patients presented with higher SCAI stage, pre-implant lactate, and rate of prior MCS devices, and fewer days from admission to implantation. Survival was lower for AMI patients at 30 days, 90 days, and discharge. No difference in time to all-cause mortality was found when excluding patients receiving transplant. There was no significant difference in complication rates between groups.

CONCLUSIONS

ADHF-CS patients with Impella 5.5 support have a significantly higher rate of survival than patients with AMI-CS. ADHF patients were successfully bridged to heart transplant more often than AMI patients, contributing to increased survival.

Reconsidering FDA Guidelines: A Single-Center Experience of Prolonged Impella 5.5 Support

OBJECTIVE

Impella 5.5 (Abiomed, Danvers, MA, USA) is approved by the US Food and Drug Administration (FDA) for mechanical circulatory support for ≤14 days. It is unknown whether prolonged support is associated with worse outcomes. We sought to review our single-center experience with Impella 5.5 and compare outcomes based on support duration.

METHODS

We retrospectively reviewed adult patients (≥18 years old) supported with Impella 5.5 at our institution (May 2020 to April 2023). Patients on prolonged support (>14 days) were compared with those supported for ≤14 days.

RESULTS

There were 31 patients supported with Impella 5.5 including 14 (45.2%) supported >14 days. Median support duration for those on prolonged support was 43.5 (interquartile range [IQR] 25 to 63.5) days versus 8 (IQR 6, 13) days for those who were not (P < 0.001). Overall, the device-related complication rate was 9.7% and did not differ between groups (P = 0.08). Overall, 30-day postimplant survival was 71% and did not differ by support duration (P = 0.2). In-hospital mortality was 32% and did not differ between cohorts (P > 0.99). Among those surviving to explant (n = 22), long-term strategy included bridge to durable ventricular assist device (18%, n = 4), cardiac transplant (55%, n = 12), and cardiac recovery (27%, n = 6).

CONCLUSIONS

High-risk patients with cardiogenic shock may be supported with Impella 5.5 beyond the FDA-approved duration without increased risk of complications or mortality.

Placement of Temporary Left Ventricular Assist Device Using Monitored Anesthesia Care and Regional Anesthesia

Patients with advanced cardiogenic shock requiring mechanical circulatory support are uniquely susceptible to clinical deterioration. Limiting physiologic perturbations via avoidance of general anesthesia and endotracheal intubation by awake Impella 5.5 placement is safe and may represent a novel strategy in mechanical circulatory support initiation among patients in cardiogenic shock. (Level of Difficulty: Intermediate.).

Comparison of Intraaortic Balloon Pump and Impella 5.5 as Heart Transplant Bridging Strategies

BACKGROUND

Temporary mechanical circulatory support is increasingly utilized as a bridge to heart transplantation. The Impella 5.5 (Abiomed) has achieved anecdotal success as a bridge since receiving US Food and Drug Administration approval. The purpose of the current study was to compare waitlist and posttransplant outcomes of patients bridged with intraaortic balloon pumps (IABPs) to those receiving Impella 5.5 therapy.

METHODS

Patients listed for heart transplantation between October 2018 and December 2021 who received IABP or Impella 5.5 at any time during waitlist course were identified from the United Network for Organ Sharing database. Propensity-matched groups of recipients with each device were created. Competing-risks regression for mortality, transplantation, and removal from waitlist for illness was performed according to the method of Fine and Gray. Posttransplant survival was censored at 2 years.

RESULTS

Overall, 2936 patients were identified, of whom 2484 (85%) were supported with IABP and 452 (15%) received Impella 5.5. Patients with Impella 5.5 support had more functional impairment, higher wedge pressures, higher rates of preoperative diabetes and dialysis, and more ventilator support (all P < .05). Waitlist mortality was significantly worsened in the Impella group and transplantation was less frequent (P < .001). However, survival at 2 years after transplant was similar in both complete (90% vs 90%, P = .693) and propensity-matched cohorts (88% vs 83%, P = .874).

CONCLUSIONS

Patients bridged with Impella 5.5 were sicker than IABP-bridged patients and less frequently transplanted; however, posttransplant outcomes were similar in propensity-matched cohorts. The role of these bridging strategies in patients listed for heart transplantation should be continually assessed with future allocation system changes.

Bridging with surgically placed microaxial left ventricular assist devices: a high-volume centre experience

OBJECTIVES

The Impella 5.0 and 5.5 have largely superseded non-ambulatory temporary mechanical support devices; yet, clinical outcomes are predominantly limited to small series: this study presents the experience of a high-volume centre.

METHODS

An institutional clinical registry was used to identify all patients with cardiogenic shock who underwent Impella 5.0 or 5.5 implantation from January 2014 to March 2022. The primary outcome was survival to device explantation.

RESULTS

The study cohort comprised 221 patients, including 146 (66.1%) Impella 5.0 and 75 (33.9%) Impella 5.5 patients. The primary aetiology was non-ischaemic cardiomyopathy (50.7%, n = 112), ischaemic cardiomyopathy (23.1%, n = 51) and acute myocardial infarction (26.2%, n = 58). Patients were prospectively classified according to strategy as bridge to transplant (47.5%, n = 105), bridge to durable device (13.6%, n = 30) or bridge to recovery (38.9%, n = 86). Patients were predominantly Interagency Registry for Mechanically Assisted Circulatory Support profile 1 or 2 (95.0%, n = 210). The median bridging duration was 14 (range 0-137) days. Device exchange, Ischaemic stroke and ipsilateral arm ischaemia occurred in 8.1% (n = 18), 2.7% (n = 6) and 1.8% (n = 4) of patients, respectively. Compared to the 75 most recent Impella 5.0 patients, Impella 5.5 patients (n = 75) had lower rates of device exchange (4.0%, n = 3 vs 13.3%, n = 10, P = 0.04). Overall, 70.1% (n = 155) of patients survived to Impella explantation.

CONCLUSIONS

The Impella 5.0 and 5.5 provide safe and effective temporary mechanical support in appropriately selected patients with cardiogenic shock. The newer device generation may have a lower requirement for device exchange as compared to its predecessor.

Pathophysiology and Management of Heart Failure in the Elderly

The population of elderly adults is increasing globally. It has been projected that the population of adults aged 65 years will increase by approximately 80% by 2050 in the United States. Similarly, the elderly population is rising in other countries; a notable example being Japan where approximately 30% of the population are aged above 65 years. The pathophysiology and management of heart failure (HF) in this age group tend to have more intricacies than in younger age groups owing to the presence of multiple comorbidities. The normal aging biology includes progressive disruption at cellular and genetic levels and changes in molecular signaling and mechanical activities that contribute to myocardial abnormalities. Older adults with HF secondary to ischemic or valvular heart disease may benefit from surgical therapy, valve replacement or repair for valvular heart disease and coronary artery bypass grafting for coronary artery disease. While referring these patients for surgery, patient and family expectations and life expectations should be taken into account. In this review, we will cover the pathophysiology and the management of HF in the elderly, specifically discussing important geriatric domains such as frailty, cognitive impairment, delirium, polypharmacy, and multimorbidity.

Microaxial Left Ventricular Assist Device in Cardiogenic Shock: A Systematic Review and Meta-Analysis

Microaxial left ventricular assist devices (LVAD) are increasingly used to support patients with cardiogenic shock; however, outcome results are limited to single-center studies, registry data and select reviews. We conducted a systematic review and meta-analysis, searching three databases for relevant studies reporting on microaxial LVAD use in adults with cardiogenic shock. We conducted a random-effects meta-analysis (DerSimonian and Laird) based on short-term mortality (primary outcome), long-term mortality and device complications (secondary outcomes). We assessed the risk of bias and certainty of evidence using the Joanna Briggs Institute and the GRADE approaches, respectively. A total of 63 observational studies (3896 patients), 6 propensity-score matched (PSM) studies and 2 randomized controlled trials (RCTs) were included (384 patients). The pooled short-term mortality from observational studies was 46.5% (95%-CI: 42.7–50.3%); this was 48.9% (95%-CI: 43.8–54.1%) amongst PSM studies and RCTs. The pooled mortality at 90 days, 6 months and 1 year was 41.8%, 51.1% and 54.3%, respectively. Hemolysis and access-site bleeding were the most common complications, each with a pooled incidence of around 20%. The reported mortality rate of microaxial LVADs was not significantly lower than extracorporeal membrane oxygenation (ECMO) or intra-aortic balloon pumps (IABP). Current evidence does not suggest any mortality benefit when compared to ECMO or IABP.

Hemolysis during short-term mechanical circulatory support: from pathophysiology to diagnosis and treatment

INTRODUCTION

Despite advances in heart failure therapies and percutaneous coronary interventions, survival for cardiogenic shock remains poor. Percutaneous ventricular assist devices (pVAD) are increasingly used, but current evidence remains conflicting. The Impella is an example of such a device, based on a catheter mounted micro-axial continuous flow pump, that has been rapidly adopted in routine practice. An important aspect in the post implantation care is the prevention of complications. Hemolysis is one of the more frequent complications seen with this device.

AREAS COVERED

In this review we discuss the pathophysiology, diagnosis and treatment of hemolysis in patients supported with a pVAD. A practical algorithm for rapid identification of hemolysis and the underlying cause is presented, allowing for early treatment and prevention of further complications.

EXPERT OPINION

Hemolysis remains a threat to patients supported with any mechanical circulatory support device. Prevention as well as treatment demands for sufficient knowledge about the device, the optimal position and hemodynamics. Future studies should try to clarify some of the elements that are still unclear such as optimal anticoagulation, the place of pentoxyfilline or extracorporeal removal of free hemoglobin. This could help to optimize outcomes in clinical practice as well as future studies.