Relationship between left ventricular global longitudinal strain, infarct size and left ventricular function in patients with acute myocardial infarction in a stem cell therapy study

Introduction

It is critically important to determine the accuracy, and relationships between, non-invasive imaging modalities, such as two-dimensional echocardiography (TTE), gated single-photon emission computed tomography (SPECT) and cardiac magnetic resonance imaging (cMRI) in patients with recent acute myocardial infarction (AMI) because these are used as clinical trial endpoints. Modest improvements in the left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV) and infarct zone size (IS) have been reported in AMI stem cells therapy trials (SCT).

Purpose

The aim of the study was to evaluate left-ventricular global longitudinal strain (GLS) in patients with AMI enrolled to SCT and assess its relation with infarct zone, LVEF and LVEDV using multimodality imaging including TTE, cMRI and SPECT.

Methods

Twenty-eight patients (21 male, 7 female, mean age 60.0±8.7 years) with first AMI, 2–5 days after left anterior descending percutaneous coronary intervention (PCI) and IS ≥10% were enrolled. GLS was evaluated with two-dimensional speckle tracking echocardiography (aCMQ, Philips Epiq 7). Infarct zone was measured using SPECT (E.CAM, Siemens) and gadolinium-enhanced cMRI (Siemens Magnetom Sonata 1.5T). LVEF and LVEDV were assessed with TTE (Auto-ROI, Philips), SPECT (GSQUAN, Siemens) and cMRI (MASS Medis). Measurements were obtained independently by blinded analysts.

Results

Mean GLS was −11.0±2.5% and showed a positive correlation with infarct zone by SPECT and MRI, negative with TTE-LVEF and cMRI-LVEF (Figure 1) and borderline with SPECT-LVEF (r=−0.35, p=0.08). There was no correlation between GLS and TTE-LVEDV (r=−0.25, p=0.25); SPECT-LVEDV (r=−0.38, p=0.077) and MRI-LVEDV (r=−0.20, p=0.365).

Patients in the third and fourth GLS quartile had a smaller IS measured by MRI and a trend toward a smaller infarct zone by SPECT (table 1). Patients in the GLS fourth quartile had higher TTE-LVEF and a trend toward higher cMRI-LVEF compared with other quartiles.

LVEF measured with TTE and cMRI was higher compared with SPECT-LVEF (+2.6±6.8%, p=0.006 and +4.2±7.8%, p=0.030, respectively) with no difference between TTE-LVEF and MRI-LVEF (p=0.823) (Table 1).

LVEDV evaluated by SPECT and MRI was higher compared with TTE-LVEDV (+48.3±24.9 ml, +47.7±29.5 ml, both p<0.001) with no difference between SPECT-LVEDV and MRI-LVEDV (p=0.984)

Conclusions

In patients with anterior wall AMI, 2–5 days after PCI, GLS showed a good correlation with infarct zone quantified by SPECT and MRI and with LVEF measured with TTE and cMRI. GLS might thus be a valuable tool in the evaluation of myocardial injury in SCT.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): STRATEGMED 265761 “CIRCULATE” National Centre for Research and Development/Poland/ZDS/00564 Jagiellonian University Medical College Table 1Figure 1

Evolution of left ventricular function after Wharton's jelly mesenchymal stem cells transcoronary administration: 5-year follow up in a pilot cohort of CIRCULATE-AMI Randomized Trial

Introduction

CIRCULATE-Acute Myocardial Infarction is a double-blind controlled trial randomizing (RCT) in 105 consecutive patients with their first, large AMI (cMRI-LVEF ≤45% and/or cMRI-infarct size ≥10% of LV) with successful infarct-related artery (IRA) primary percutaneous coronary intervention (pPCI) to transcoronary administration of Wharton's Jelly Mesenchymal Stem Cells (WJMSCs) vs. placebo (2:1). The pilot study cohort (PSC) preceded the RCT.

Aim

To evaluate WJMSCs long-term safety, and evolution of left-ventricular (LV) function in CIRCULATE-AMI PSC.

Material and methods

30 000 000 WJMSCs (50% labelled with 99mTc-exametazime) were administered via IRA in a ten-patient PCS (age 32–65 years, peak hs-Troponin T 17.3±9.1ng/mL and peak CK-MB 533±89U/L, cMRI-LVEF 40.3±2.7% and infarct size 20.1±2.8%) at ≈5–7 days after AMI using a cell delivery-dedicated, coronary-non-occlusive method. Other treatments were per guidelines.

WJMSCs showed an unprecedented high myocardial uptake (30.2±5.3%; 95% CI 26.9–33.5%), corresponding to ≈9×10 000 000 cells retention in the infarct zone – in absence of epicardial flow or myocardial perfusion impairment (TIMI-3 in all; cTFC 45±8 vs. 44±9, p=0.51) or any hs-Troponin T elevation. Five-year follow up included cardiac Magnetic Resonance Imaging (cMRI) (at baseline, 1 year and 3 years) and detailed echocardiography (echo) at baseline, 1 year, 3 years and 5 years.

Results

By 5 years, one patient died from a new, non-index territory AMI. There were no other cardiovascular events and MACCE that might be related to WJMSCs transplantation.

On echo (Fig), there was an increase in left ventricular ejection fraction (LVEF) between WJMSCs administration point and 1 year (37.7±2.9% vs. 48.3±2.5%, p=0.002) that was sustained at 3 years (47.2±2.6%, p=0.005 vs. baseline) and at 5 years: (44.7±3.2%, p=0.039 vs. baseline). LVEF reached a peak at 1 year after the AMI and WJMSCs transfer (Fig). cMRI data (obtained up to 3 years; 1 year 41.9±2.6% vs. 51.0±3.3%, p<0.01; 3 years 52.2±4.0%, p<0.01 vs. baseline) were consistent with the echo LVEF assessment.

Conclusions

5-year follow up in CIRCULATE-AMI PSC indicates that WJMSC transcoronary application is safe and may be associated with an LVEF improvement. The magnitude of LV increase appears to peak at 1 year, suggesting a potential role for repeated WJMSCs administration(s). Currently running double-blind RCT will provide placebo-controlled insights into the WJMSCs effect(s) on changes in LV function, remodelling, scar reduction and clinical outcomes.

Echo-LVEF evolution

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): STRATEGMED 265761 “CIRCULATE” National Centre for Research and Development/Poland/ZDS/00564 Jagiellonian University Medical College

P774Transcoronary transfer of Wharton's jelly mesenchymal pluripotent stem cells in patients with chronic ischaemic heart failure shows safety and unprecedented high-grade myocardial uptake

Background

Chronic ischaemic heart failure (CIHF) remains an important health problem on the patient/family- and society level. In animal models, Wharton's jelly (umbilical cord matrix) multipotent stem cells (WJMSCs) effectively promote angiogenesis, can differentiate to cardiomyocytes, and drive functional myocardial regeneration. Effective uptake of regenerative cells in ischaemic-impaired tissue is fundamental for any therapeutic effect.

Purpose

To evaluate safety and myocardial uptake of WJMSCs transcoronary transfer in CIHF applied as a novel myocardial regeneration strategy employing allogenic yet hypo-immunogenic, off-the-shelf “unlimited” source of therapeutic cells (NCT03418233 pilot cohort).

Material and methods

In ten consecutive patients (age 62.6±2.5), with stable CIHF and no current need for revascularization (LVEF 29.3±3% by echo and 26.3±6% by SPECT; NT-proBNP 1746±329pg/mL; myocardial scar tissue 39.9±3.9% by SPECT) and patency of at least two major native coronary arteries or by-pass graft(s), the CardioCell Investigational Medical Product, based on 30x106 WJMSCs, was administered to viable yet hypokinetic segments using a novel algorithm including a dedicated catheter for transcoronary delivery of cellular therapies. The cells were labeled with 99mTc-extametazime to routinely evaluate their myocardial uptake magnitude.

Results

No symptoms or signs of novel myocardial ischaemia occurred with cell delivery and no patient showed any adverse periprocedural events. One hour after administration, myocardial WJMSCs uptake (SPECT) was 40.3±6%; see Fig for a typical raw data image. By 6 months there were no adverse events in the study cohort.

Figure 1

Conclusions

This work indicates safety and unprecedented high-grade myocardial uptake of WJMSCs in CIHF patients. Together with animal data, this provides basis for continued assessment of this strategy in an endpoint-powered randomized controlled clinical trial employing CardioCell as an “unlimited” off-the-shelf cellular therapy strategy.

Acknowledgement/Funding

K/ZDS/005644 and 265761 (National Centre for Research and Development STRATEGMED)

P4604Insights into left ventricular remodelling and clinical outcomes after Wharton's jelly multipotent stem cells transcoronary administration in a pilot cohort of CIRCULATE-AMI Trial (NCT03404063)

Introduction

CIRCULATE-Acute Myocardial Infarction Trial (NCT03404063) is a double-blind controlled trial (RCT) that is randomizing consecutive patients with their first, large AMI (LVEF ≤45% and/or cMRI -infarct size ≥10% of LV) successfully treated by infarct-related artery (IRA) primary percutaneous coronary intervention reperfusion (TIMI ≥2) to transcoronary administration of Wharton Jelly Multipotent Stem Cells (WJMSCs) vs. placebo (2:1), preceded by evaluation of safety, WJMSCs myocardial uptake, and echocardiographic, cMRI and SPECT left ventricular remodelling and hemodynamic changes in pilot study cohort (PSC).

Purpose

To evaluate LV remodelling and hemodynamic features following WJMSCs transplantation in CIRCULATE-AMI PSC.

Methods

Ten consecutive patients (age 32–65 years) were administered 30 000 000 WJMSCs via the infarct-related artery at ≈5–7 days after AMI using transradial approach and a coronary-non-occlusive catheter dedicated to cell delivery. Within 3 years of follow up SPECT was performed at baseline and 1 year, echo and cMRI were performed at baseline, 1 year and 3 years.

Results

3-year observation (cMRI) shows a significant decrease of median left ventricular mass (LVM) between WJMSCs administration and 1 year 140 g (IQR 128–150) vs. 97 g (95–128), that is sustained at 3 years 93 g (80–119), p<0,001. There were no significant changes of left ventriular end-diastolic volume (LVEDV) in all diagnostic methods: SPECT baseline vs. 1 year (157.1±27.1 ml vs. 174±24 ml); cMRI baseline vs. 1 year vs. 3 years (171.6±17.7 ml vs. 198.2±23.4 ml vs. 181.9±17.6 ml) and Echo (137±13.3 ml vs. 135±2.9 ml vs. 148±21.8 ml), p value >0,05 for all. Furthermore, there was a significant increase in stroke volume measured by SPECT baseline vs. 1 year (53.3±7.6 ml vs. 68.2±5.2ml); cMRI baseline vs. 1 year vs. 3 years (72.7±5.2 ml vs. 96.9±8.1 ml vs. 93.2±7.8 ml) and Echo (64.3±2.9 ml vs. 68.8±4.1 ml vs. 81.9±7.1 ml), p<0,05 for all. By 3 years there was one non-index territory AMI. There were no other adverse events in the study cohort.

cMRI Left Ventricular Mass evolution

Conclusions

Long-term follow up in CIRCULATE-AMI PSC suggests that transcoronary administration of WJMSCs in a recent large AMI in humans might be associated with an inhibition of LV adverse remodelling and a significant hemodynamic improvement. Our currently running randomized double-blind controlled trial will verify LV remodelling evolution in WJMSCs-treated patients.

Acknowledgement/Funding

K/ZDS/00564 Jagiellonian University Medical College; STRATEGMED 265761 “CIRCULATE” National Centre for Research and Development/Poland

P1471Multimodality imaging of left ventricular function and volumes in patients with acute and chronic myocardial injury - Novel insights

Introduction

The three main techniques to evaluate myocardial function and volumes: two-dimensional echocardiography (TTE), gated single photon emission computed tomography (SPECT) and cardiac magnetic resonance imaging (cMRI), have important differences in accessibility and practicality.

Purpose

We aimed to evaluate: TTE, SPECT and cMRI in the measurement of left ventricular ejection fraction (LVEF), left ventricular end-diastolic (LVEDV) and left ventricular end-systolic volumes (LVESV) in patients with acute and chronic myocardial ischemic injury.

Methods

Consecutive patients with first large acute myocardial infarction (AMI) [LVEF ≤45% and/or cMRI infarct size ≥10% of left ventricle, 2–5 days after pPCI, n=10] and patients with chronic ischemic heart failure (CIHF) [LVEF ≤45% by SPECT, NYHA class II or III, n=10] were enrolled. Multimodality imaging using the study techniques was performed within 36 hours.

Results

LVEF measured with TTE, SPECT and cMRI did not differ between both groups (AMI: 41±2.5%, 37.9±2.7%, 41±2.7%; p=0.07, CHF: 29.6±3.2%, 29.7±3.0%, 32.9±4.9%; p=0.42). LVEDV and LVESV evaluated by SPECT were +33.6%, +38.2% higher in the AMI group and +40.7%, 40.4% higher in the CIHF group compared with TTE (p<0.001). When measured with cMRI they were +52.1%, +50.5%, +31.5%, +25.5% higher (AMI, CIHF group, respectively), compared with TTE (p<0.001).

There was a strong positive correlation between LVEF derived from TTE and SPECT (r=0.81, AMI; r=0.92, CIHF), TTE and cMRI (r=0.89, AMI; r=0.75, CIHF), SPECT and cMRI (r=0.88, AMI; r=0.76, CIHF; all p<0.01). As well as for LVEDV (r=0.79, 0.88; 0.90, 0.85; 0.76, 0.87; all p<0.05) and LVESV measurements (r=0.90, 0.91; 0.94, 0.89; 0.85, 0.85, all p<0.05).

Figure 1

Conclusions

There is a strong correlations between TTE, SPECT, and cMRI in the assessment of left ventricular function in patients with AMI or CIHF. However, TTE appears to significantly underestimate left ventricular volumes in relation to SPECT and cMRI.

Polymorphism in the chemokine receptor 7 gene (CCR7) is associated with previous myocardial infarction in patients undergoing elective coronary angiography

Coronary artery disease (CAD) remains a major cause of death in developed countries. Both environmental and, less known, genetic factors contribute to progression of CAD to myocardial infarction (MI). Immune system is activated in patients with CAD through dendritic cells (DCs), which present plaque antigens to T lymphocytes. Production of proinflammatory cytokines by activated T cells contributes to plaque rupture in MI. Chemokine receptor 7 (CCR7) on DCs is required for their chemotaxis from plaque to lymph nodes. This makes possible an interaction of DCs with T lymphocytes and initiation of specific immune response. We hypothesized that single nucleotide polymorphisms (SNPs) in CCR7 gene locus are associated with previous MI in patients with CAD. To test this hypothesis, we genotyped six SNPs from the CCR7 gene locus in 300 consecutive patients, admitted for elective coronary angiography. We performed univariate-, multivariate- (including potential confounders) and haplotype-based tests of association of SNPs with previous MI and results of angiography. Allele A of rs17708087 SNP was associated with previous MI. This association remained significant after adjustment for age, sex, smoking, hypercholesterolaemia and drugs used by patients (odds ratio 2.13, 95% confidence interval: 1.13-3.86). Therefore, we conclude that CCR7 gene locus harbours a polymorphism that modifies risk of MI in patients with CAD. Replication of this association could be sought in a prospective cohort of initially healthy individuals.

Measurement of angiotensin metabolites in organ bath and cell culture experiments by liquid chromatography - electrospray ionization - mass spectrometry (LC-ESI-MS)

The metabolism of renin-angiotensin system (RAS) is more complicated than previously expected and understanding the biological phenomena regulated by variety of angiotensin metabolites requires their precise and possibly comprehensive quantitation. Physiological concentrations of angiotensins (Ang) in biological fluids are low, therefore their accurate measurements require very sensitive and specific analytical methods. In this study we developed an accurate and reproducible method of quantitation of angiotensin metabolites through coupling of liquid chromatography and electrospray ionization - mass spectrometry (LC-ESI-MS). With this method main angiotensin metabolites (Ang I, II, III, IV, 1-9, 1-7, 1-5) can be reliably measured in organ bath of rat tissues (aorta, renal artery, periaortal adipose tissue) and in medium of cultured endothelial cells (EA.hy926), exposed to Ang I for 15 minutes, in the absence or in the presence of angiotensin converting enzyme inhibitor, perindoprilat. Presented LC-ESI-MS method proved to be a quick and reliable solution to comprehensive analysis of angiotensin metabolism in biological samples.