Significant aortic stenosis associated with poorer functional outcomes in patients with acute ischaemic stroke undergoing endovascular therapy

BACKGROUND AND AIM

Bi-directional feedback mechanisms exist between the heart and brain, which have been implicated in heart failure. We postulate that aortic stenosis may alter cerebral haemodynamics and influence functional outcomes after endovascular thrombectomy for acute ischaemic stroke. We compared clinical characteristics, echocardiographic profile and outcomes in patients with or without aortic stenosis that underwent endovascular thrombectomy for large vessel occlusion acute ischaemic stroke.

METHODS

Consecutive acute ischaemic stroke patients with anterior and posterior circulation large vessel occlusion (internal carotid artery, middle cerebral artery and basilar artery) who underwent endovascular thrombectomy were studied. Patients were divided into those with significant aortic stenosis (aortic valve area <1.5 cm2) and without. Univariate and multivariate analyses were employed to compare and determine predictors of functional outcomes measured by modified Rankin scale at three months.

RESULTS

We identified 26 (8.5%) patients with significant aortic stenosis. These patients were older (median age 76 (interquartile range 68-84) vs. 67 (interquartile range 56-75) years, p = 0.001), but similar in terms of medical comorbidities and echocardiographic profile. Rates of successful recanalisation (73.1% vs. 78.0%), symptomatic intracranial haemorrhage (7.7% and 7.9%) and mortality (11.5% vs. 12.6%) were similar. Significant aortic stenosis was independently associated with poorer functional outcome (modified Rankin scale >2) at three months (adjusted odds ratio 2.7, 95% confidence interval 1.1-7.5, p = 0.048), after adjusting for age, door-to-puncture times, stroke severity and rates of successful recanalisation.

CONCLUSION

In acute ischaemic stroke patients managed with endovascular thrombectomy, significant aortic stenosis is associated with poor functional outcome despite comparable recanalisation rates. Larger cohort studies are needed to explore this relationship further.

Haemostatic parameters related to lipids and adhesion molecules

Several components of blood, e.g. lipids, coagulation and fibrinolytic factors, are thought to be important risk factors in cardiovascular diseases. The aim of this study was to correlate these risk factors and the soluble adhesion proteins, soluble P-selection (sP-selectin) and soluble vascular cell adhesion molecule (sVCAM-1), in healthy men and women as well as to unravel any effects of smoking. One hundred and forty-two fasting men (median age 36 years) including 39 smokers, and 124 women (median age 34 years) including 35 smokers, were tested between 0800 h and 1000 h. Fibrinogen correlated positively with white blood cells (WBC) (r = 0.25), prothrombin fragment 1.2 (F1.2) (r = 0.21), cholesterol (r = 0.27), beta-thromboglobulin (r = 0.29), Factor VII clotting activity (FVIIc) (r = 0.27) (all P < 0.0001), tissue plasminogen activator antigen (t-PAag) (r = 0.22, P < 0.0005), plasminogen activator inhibitor-1 antigen (PAI-1ag) (r= 0.20) and VCAM-1 (r= 0.19) (both P< 0.002). Cholesterol and triacylglycerol (TG) correlated positively with t-PA antigen (t-PAag) (r = 0.36 and r = 0.38), PAI-1 antigen (PAI-1ag) (r = 0.35 and r = 0.50), P-selectin (r = 0.26 and r = 0.27) (all P < 0.0001) and WBC (r = 0.17, P < 0.007 and r = 0.18, P < 0.004). Cholesterol correlated also with F1.2 (r = 0.29) and TG (r= 0.44) (P< 0.0001). In addition to cholesterol and TG, sP-selectin correlated postively with PAI-1ag (r= 0.39), t-PAag (r= 0.27) and WBC (r = 0.25) (all P < 0.0001). Comparing the various test parameters in men and women, it was found that women had significantly higher levels of F 1.2 and high-density lipoprotein-cholesterol than men, whereas men had higher levels of t-PAag, PAI-lag and P-selectin than women. Smoking was associated with a rise in several of the test parameters. It can be concluded that there are correlations between several risk factors. Of particular interest is the positive correlation between sP-selectin and a number of established risk factors of cardiovascular diseases.

Human leukocyte elastase and cathepsin G inactivate factor VII by limited proteolysis

The effect of supernatant from phorbol myristate acetate (PMA) stimulated human polymorphonuclear granulocytes (PMN) on human factor VII was studied in vitro. The supernatant caused a rapid loss in factor VII coagulant activity by the action of human leukocyte elastase (HLE) and cathepsin G in the supernatant, as demonstrated by the use of specific inhibitors of the two serine proteases, respectively. Preincubation of the supernatant with the elastase inhibitor and the cathepsin G inhibitor preserved 80% and 25% of the clotting activity, respectively. Calcium protected factor VII completely from the supernatant mediated inactivation. Cathepsin G and HLE purified from PMN each destroyed the coagulant activity of factor VII when added to a non-plasma system. There were, however, no effect on factor VII activity when cathepsin G was added to plasma. Polyacrylamide gel electrophoresis in the presence of SDS indicated that HLE and cathepsin G cleaved the zymogen in the same manner, producing (a) peptide(s) of low molecular mass and a single large product of 48 kDa. Preincubation of factor VII with calcium ions inhibited the proteolytic action of HLE and cathepsin G. It is suggested that HLE and cathepsin G from activated granulocytes may be partly responsible for the loss in factor VII activity that is observed during sepsis.