Elevated soluble lectin-like oxidised low-density lipoprotein receptor-1 (sLOX-1) associated with increased risk for heart failure and MACE after an acute coronary event

Background/Introduction

The lectin-like oxidised low-density lipoprotein receptor (LOX-1) is involved in atherosclerotic plaque inflammation and vulnerability. Plasma levels of soluble LOX-1 (sLOX-1) have previously been associated with increased risk for recurrent coronary events and mortality in patients with acute coronary syndrome (ACS).

Purpose

To assess the association of sLOX-1 with the development of heart failure (HF) post-ACS.

Methods

We measured sLOX-1 in 524 patients with ACS within 24 hours after the acute event. A subgroup of 97 of these patients completed a follow-up echocardiogram after one year. The incidence of HF-related hospitalisation and recurrent major adverse cardiovascular events (MACE), defined as recurrent ACS or cardiovascular death, was followed for a mean period of two years. In a separate cohort of 363 patients with ACS and percutaneous coronary intervention (PCI), we studied the correlations between sLOX-1, coronary flow reserve, left ventricular systolic function and systemic inflammation at two follow-up visits within four weeks and 16 weeks post-ACS, respectively.

Results

Baseline sLOX-1 was positively associated with the risk of HF and MACE, independently of traditional cardiovascular risk factors, revascularisation and medication. The hazard ratios and 95% confidence intervals were 1.57 (1.10–2.23), p=0.012 for HF and 1.36 (1.08–1.71), p=0.009 for MACE per standard deviation baseline sLOX-1 increase. Elevated sLOX-1 was also negatively associated with lower-left ventricular ejection fraction at one year (r=−0.263, p=0.009). In the second ACS cohort, we found that plasma sLOX-1 measured at the two follow-up visits was negatively associated with coronary flow reserve and left ventricular systolic function, and positively correlated with biomarkers of systemic inflammation and cardiac overload.

Conclusion

Elevated sLOX-1 is associated with the development of HF and recurrent cardiovascular events in patients with ACS. Although this association study cannot confirm causality, the results suggest LOX-1 as a potential biomarker and treatment target in patients with ACS.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): • Swedish Research Council • The Swedish Heart and Lung foundation• Swedish Foundation for Strategic Research Dnr IRC15-0067 • Marianne and Marcus Wallenberg Foundation • Bundy Academy at Lund University

Resting coronary blood flow velocity profile predicts coronary flow reserve in HFpEF

Background

Coronary microvascular disease (CMD) is prevalent in patients with heart failure with preserved ejection fraction (HFpEF). CMD can be assessed by coronary flow reserve (CFR) using transthoracic echocardiography (TTE). We hypothesised that the coronary Doppler flow profile in LAD at rest could reveal information about the downstream resistance in the vessel, where increased resistance is a sign of CMD.

Purpose

We aimed to measure features of the acceleration and deceleration of the LAD Doppler flow profile to investigate association with coronary and cardiac function.

Methods

CFR was assessed in 202 patients by TTE in the PROMIS-HFpEF-study. Detailed flow profile measurements were possible in 169 patients (84%) who constituted the study population. The coronary Doppler flow profiles were analysed with respect to acceleration time (corAT) and slope (corAS) and deceleration pressure half time (corPHT) (figure 1).

Results

The average age was 75±9 years and 55% were female. Atrial fibrillation (AF) was present in 53% and 62% were current or previous smokers. There was no significant difference in gender, age, BMI, blood pressure or heart rate in the CMD vs non-CMD group, but AF as well as a history of smoking was more prevalent in the CMD group, p=0.022 and 0.003 respectively. Further, there were no significant differences in neither corAT nor corAS between the two groups. However, patients with CMD had shorter corPHT of 268±64 ms compared to 298±67 ms, p=0.01. A longer corPHT was associated with increased TAPSE (R=0.205, p=0.007) and higher CFR (R=0.231, p=0.002). In a multivariable analysis adjusted for age, sex, BMI, SBP, reactive hyperemia index, HR, AF, diabetes, CVD, smoking, LVM and study site*, corPHT independently predicted CFR (table 1, p=0.016).

Conclusion

Short pressure half time, indicating a steep deceleration of the coronary Doppler signal at rest, may provide useful information for prediction of CFR determined by transthoracic ultrasound by reflecting the increased resistance in the coronary microvasculature associated with CMD.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Sahlgrenska University Hospital, Sponsor AstraZeneca

Retrograde blood flow in the aortic arch determined by transesophageal Doppler ultrasound

BACKGROUND

Aortic arch atheromas may be important sources of cerebral embolism. Aortic plaques are frequently found somewhat distal to the origin of the cerebral arteries, implying that cerebral embolization from such plaques depends on local retrograde blood flow components in this area. Therefore, we investigated the occurrence of blood flow reversal in this part of the aorta. Furthermore, since the presence and magnitude of retrograde flow might be influenced by aortic wall properties, we also studied the relationship between plaque size and distribution, aortic strain and degree of retrograde flow.

METHODS

We evaluated aortic arch ante- and retrograde blood flow velocities in 56 patients by transesophageal echocardiography using color-Doppler-guided pulsed-Doppler techniques. The velocity-time integrals (VTI) were measured and the diastolic/systolic VTI ratio was calculated.

RESULTS

Retrograde diastolic blood flow was noted in all subjects, and diastolic/systolic VTI ratios were higher (p < 0.05) in patients with plaque >or=4 mm (n = 17) compared to those (n = 39) without. Patients exhibiting plaques exclusively in the aortic arch showed the highest VTI ratios (p < 0.01) and tended to have the lowest strain values. Aortic strain was also reduced in patients >50 years of age (p < 0.01).

CONCLUSIONS

Our findings demonstrate retrograde aortic flow in all subjects and its proportion increases in subjects with atherosclerosis, particularly in the aortic arch. Aortic plaques situated distally to the origin of the cerebral arteries are therefore possible sources of cerebral emboli.