Extracorporeal cardiopulmonary resuscitation: a national study on the association between survival and biomarkers of hypoperfusion, inflammation, and organ failure

Background

In refractory out-of-hospital cardiac arrest (OHCA) with prolonged whole-body ischemia, global tissue injury proceeds even after establishment of circulation with extracorporeal cardiopulmonary resuscitation (ECPR).

Purpose

We aimed to investigate the role of biomarkers reflecting hypoperfusion, inflammation, and organ injury in prognostication of patients with refractory OHCA managed with ECPR.

Methods

This nationwide retrospective study included 226 adults with refractory OHCA managed with ECPR in Denmark (2011–2020). Biomarkers at admission and consecutively two days after ECPR initiation were retrieved. Odds ratio (OR) of 90-day survival were assessed by logistic regression analyses. Cut-off values were calculated from area under the curve (AUC) via the Youden index.

Results

Fifty-six patients (25%) survived to hospital discharge, all were still alive after 90-days and 91% had a favorable neurological status at discharge. Factors independently associated with 90-day survival were: male sex, shockable presenting rhythm, low flow time, platelets, pH, lactate, C-reactive protein, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and creatine kinase MB (CK-MB) level. Comparing the ability of standard predictive variables (age, sex, shockable presenting rhythm, witnessed arrest, and low flow time) and selected biomarkers (from multivariate analyses) in predicting 90-day survival, biomarkers day 2 after OHCA were significantly better than standard variables (AUC 0.79 vs. 0.56, p=0.01).

Conclusion

Biomarkers of hypoperfusion (low lactate and high pH), inflammation (high platelets and CRP), and organ failure (low LDH, ALP, and CK-MB) were independently associated with 90-day survival. Biomarkers on day 2 after OHCA (d-dimer, ALP, and CK-MB) were more predictive of 90-day survival than standard predictive variables.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Odense University Hospital's and Rigshospitalet's Common Research Foundation

Selection of patients for mechanical circulatory support for refractory out-of-hospital cardiac arrest: a Danish nationwide multicenter study

Background

Extracorporeal cardiopulmonary resuscitation (ECPR) is a potential salvage therapy for selected patients with refractory out-of-hospital cardiac arrest (OHCA).

Purpose

The objective of this study was to describe the characteristics of potential ECPR patients.

Methods

This retrospective, observational cohort study included 579 patients admitted with refractory OHCA for possible ECPR at all tertiary cardiac arrest centers in Denmark between 2015 and 2020. Presenting characteristics, reasons for refraining from ECPR, and survival to hospital discharge were recorded.

Results

After initial evaluation, 221 patients (38%) proceeded to ECPR, and 358 (62%) were considered futile. Median prehospital low-flow time was 70 minutes [interquartile range 56–85] in ECPR patients and 62 minutes [48–81] in no-ECPR patients, p<0.001. Intra arrest transport was more than 50 km in 92 (42%) ECPR patients and 135 in no-ECPR patients (38%), p=0.25. Treatment decision was taken by a team of three specialists in 513 cases (97%). The leading cause for not initiating ECPR was duration of low flow time (39%). Severe metabolic derangement and low end-tidal CO2 (ETCO2) were contributing factors in 35% and 31%, respectively, Figure 1. 83% of the patients had two or more contributing factors recorded as reasons for not initiating ECPR, Figure 2. The most prevailing combination of contributing factors were non-shockable rhythm, low ETCO2, and metabolic derangement or duration of prehospital low flow time combined with low ETCO2. Survival to discharge was achieved in six patients (1.7%) in the no-ECPR group and 50 (23%) in the ECPR group.

Conclusions

In this large nationwide study of patients admitted for possible ECPR, 62% were not treated with ECPR. The most frequent reasons to abstain from ECPR were duration of prehospital low flow time, metabolic derangement, and low ETCO2.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): The Danish Heart Foundation

Soluble suppression of tumorigenicity associated to post-procedural no-or-slow-reflow phenomenon in ST-elevation myocardial infarction

Background

Over the last decades, the prognosis for patients with ST-elevation myocardial infarction (STEMI) has improved due to primary percutaneous coronary intervention (pPCI). However, no-or-slow-reflow phenomenon after pPCI constrains this benefit. Suppression of tumorigenicity (sST2) is released from vascular endothelial cells in response to myocyte stretch and increased sST2 level in the initial phase of STEMI is a useful prognostic biomarker for predicting mortality and heart failure (HF).

Purpose

To explore the association of sST2 with post-procedural no-or-slow-reflow phenomenon in patients with STEMI.

Method

During a 1-year period in 2015/2016, the study included consecutive STEMI patients from two heart centers who underwent acute coronary angiography (CAG). Blood samples including sST2 levels were collected at admission and before angiography and/or revascularization. Post-procedural coronary flow was assessed according to thrombolysis in myocardial infarction (TIMI) classification for STEMI. We divided patients into two groups: TIMI 0,1 and 2 as no-or-slow-reflow, and TIMI 3 as normal reflow. Both troponin I and troponin T were used and therefore combined and grouped into 10th percentile levels. The association between sST2 and TIMI flow was explored using multiple logistic regression adjusted for age, gender, hypercholesterolemia, diabetes, hypertension, cardiogenic shock, time from onset of symptoms to CAG, and troponin levels.

Results

In total, 1,789 consecutive patients with verified STEMI and available TIMI flow classification were included in the analysis. Of these, 1,693 (94.6%) classified as normal reflow and 96 (5.4%) as no-or-slow-reflow. The proportion of male sex was similar (1,253 (74%) vs 67 (70%), p=0.36) in the two groups. No-or-slow-reflow patients were older (median 68 years (IQR 57–75) vs median 63 years (IQR 54–72), p=0.02) and more likely to develop cardiogenic shock (22 (23%) vs 146 (8.6%), p<0.001). The troponin level was similar in the two groups (no-reflow: 5.50 (2.00, 8.00) vs normal reflow: 5.00 (3.00, 7.00), p=0.38). In the regression model, sST2 was independently associated with post-procedural no-or-slow-flow (two-fold sST2 increase: OR 1.37 (1.09, 1.70, p=0.006)).

Conclusion

In patients with STEMI, sST2 level at admission before coronary angiography is associated with the post-procedural no-or-slow-reflow phenomenon.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Righospitalets Forskningsfond AND Lundbeck Foundation

P1785 Hemodynamic determinants of left atrial function in patients with primary mitral regurgitation

Background

2D speckle tracking (2DSE) has been recently used as an advanced method for assessment of left atrial (LA) function.

Purpose

The aim of the study was to determine the association between LA function assessed with 2DSE and severity of mitral regurgitation, filling pressures and symptomatic status in patients with primary mitral regurgitation (MR).

Methods

61 patients (age 65 ± 9 years, 77% males) with primary mitral prolapse and moderate to severe MR (effective regurgitant orifice (ERO) > 0.30 cm2) and left ventricular ejection fraction > 60% were enrolled. Right heart catheterization during rest and exercise, and transthoracic echocardiography during rest was performed. Pulmonary capillary wedge pressure (PCWP) was measured at rest and peak exercise. Echocardiographic average values of LA peak contractile, conduit and reservoir strain were obtained using 2DSE in the apical 4 and 2 chamber views.

Results

LA volume index was less than 34 ml/m2 in 54 patients, and LA function based on 2DSE was abnormal in majority. LA function was associated with ERO (Figure). Patients with severe MR defined as ERO > 0.40 cm2 had significant higher reservoir strain (27.5 ± 5.1% vs. 24.5 ± 5.1 %, p = 0.02) and conduit strain (16.0 ± 4.9 %, vs. 13.1 ± 3.2 %, p = 0.008), but LA peak contractile strain was unchanged (11.4 ± 3.4 % vs. 11.8 ± 3.5 %, p = 0.69). In contrast no association between LA function, symptoms and PCWP at rest or exercise was found in our cohort. In linear regression analysis MR (ERO > 0.40 cm2) was associated with conduit (β=2.8, p = 0.02) and reservoir strain (β=3.0, p = 0.04) after adjustment for age, gender, symptoms and PCWP with exercise, whereas LA peak contractile was not.

Conclusions

LA function assessed with 2DSE was affected in patients with primary MR. Strain parameters were associated with severity of mitral regurgitation, but there was no association with symptomatic status or filling pressure at rest or exercise.

Abstract P1785 Figure

P1728Cardiogenic shock patients: those with and those without out-of-hospital cardiac arrest are different clinical entities

Introduction

Cardiogenic shock (CS) due to myocardial infarction (MI) carries 30-day mortality rates as high as 50%. The vast majority of study cohorts assessing mortality in CS comprise both patients presenting with and without out-of-hospital cardiac arrest (OHCA). Patients with and without OHCA are likely to represent two distinctive entities, which may be problematic to combine in an intervention trial.

Purpose

The aim of the study was to compare CS due to MI patients presenting with and without OHCA in terms of patient characteristics and outcome.

Methods

In the period from 2010–2017 all patients admitted at two tertiary heart centres in Denmark with CS following MI were individually identified and validated through patient records. The two centres have a catchment area of 3.9 million citizens corresponding to two-thirds of the Danish population.

Results

A total of 1716 CS patients were identified, of which 42% presented with OHCA. OHCA patients were younger (mean 63 vs 67 years), more frequently male (85 vs 67%), had higher lactate concentration (median 6.2 vs 5.0 mmol/L) on admission and higher left ventricular ejection fraction (median 30 vs 25%) compared to patients without OHCA (p<0.0001 for all). Patients presenting with OHCA had lower 30-day mortality compared to patients without OHCA (49% vs. 57%, respectively, plogrank<0.0001, Figure). Cause of in hospital death differed markedly between the two groups. Not surprisingly, anoxic brain damage was the leading cause of in hospital death in the OHCA group (56%) and only seen in 4% of patients without OHCA. In contrast, cardiac failure was the main cause of death in hospital death among patients without OHCA (60%), compared to 27% in patients with OHCA (p<0.0001).

Figure 1

Conclusion

Among patients with CS due to MI, overall 30-day mortality was significantly lower in patients presenting with OHCA. Anoxic brain damage was the main cause of in hospital death among OHCA patients, whereas fatal heart failure prevailed in patients without OHCA. Combining these two groups in a single trial with one specific intervention seems inappropriate and likely to cause an imbalance in the signal-to-noise ratio.

Acknowledgement/Funding

The Danish Heart Foundation and a research grant from Abiomed

P4625On women with ST-elevation myocardial infarction: raised concentrations of pro-C-type natriuretic peptide predict increased one-year mortality

Introduction

Endothelial C-type natriuretic peptide (CNP) contributes to the local regulation of vascular homeostasis including a vasodilatory function in the microcirculation when studied in animal models. Clinical investigations have shown that high concentrations of C-type natriuretic peptides in plasma are associated with adverse clinical outcome in subgroups of patients with cardiac disease.

Purpose

To determine the prognostic potential of pro-C-type natriuretic peptide (proCNP) measurement in plasma sampled on admission of patients with ST-elevation myocardial infarction (STEMI).

Methods

In 1760 patients (470 women, 1290 men) with confirmed STEMI, we measured proCNP concentration in plasma obtained on hospital admission before coronary angiography. We divided patients into groups of low, normal or raised proCNP concentrations based on lower and upper cut-off values of sex- and age-specific 95% reference intervals from a reference population (688 individuals). We estimated differences in baseline characteristics including medical history and determined the prognostic value of proCNP measurement by Kaplan-Meier plots including log-rank tests and Cox regression survival analyses (expressed as hazard ratio (HR) and 95% confidence interval).

Results

Raised proCNP concentrations in plasma were associated with a higher prevalence of hypertension (P<0.001), diabetes mellitus (P=0.009), and peripheral artery disease (P=0.023), and a higher one-year all-cause mortality rate compared with normal proCNP concentrations (Plog-rank = 0.009, HR: 1.6 (1.1–2.4)). However, when adjusted for sex, an interaction between sex and groups of normal vs. raised proCNP was found (P=0.030). In sex-stratified analyses only women with raised proCNP concentrations showed an increased one-year all-cause mortality rate (women: Plog-rank <0.001, HR: 2.6 (1.5–4.6), men: Plog-rank= 0.66, HR: 1.1 (0.6–1.9)). Furthermore, in women, stepwise increases of proCNP concentration in the upper range (proCNP concentration > median) were independently associated with increased risk of death within one year after adjusting for age, plasma concentrations of creatinine and proANP, and quartiles of plasma troponins (HR: 1.02 (1.00–1.05) per 1 pmol/L increase of proCNP, P=0.047).

One-year all-cause mortality rates

Conclusion

In patients with STEMI, a raised concentration of proCNP from plasma sampled on admission was associated with a higher risk of death within one year. However, only women displayed this difference of mortality rate in sex-specific estimates. Moreover, stepwise increases of proCNP concentration in the upper range independently predicted a higher risk of one-year death in women following STEMI after adjusting for potential confounders.