Diastolic function in young patients with cryptogenic stroke: A case-control pilot study

Right atrium and cryptogenic ischaemic stroke in the young: a case-control study

Background

Recent studies suggest left atrial (LA) dysfunction in cryptogenic stroke. We studied the dynamics of right atrium (RA) and right atrial appendage (RAA) in young adults with cryptogenic stroke. We hypothesised that bi-atrial dysfunction and blood stagnation might contribute to thrombosis formation in patients with patent foramen ovale (PFO), as deep venous thrombosis is detected only in the minority of patients.

Methods

Thirty patients (aged 18–49) with a first-ever cryptogenic stroke and 30 age-matched and sex-matched stroke-free controls underwent cardiac magnetic resonance (CMR) imaging. An approach to estimate the RAA volume was developed, using crista terminalis and pectinate muscles as anatomical landmarks. Atrial expansion indices were calculated as (maximal volume – minimal volume) ×100%/minimal volume. Total pulmonary to systemic blood flow ratio (Qp/Qs) was based on phase contrast CMR. Right-to-left shunt (RLS) was evaluated with transoesophageal echocardiography in 29 patients and transcranial Doppler in 30 controls, moderate-to-severe RLS considered as clinically significant.

Results

We found that RA and RAA volumes were similar between patients and controls. Also, RA expansion index was similar, but RAA (95.6%±21.6% vs 108.7%±25.8%, p=0.026) and LA (126.2%±28% vs 144.9%±36.3%, p=0.023) expansion indices were lower in patients compared with controls. Seven (24%) of 29 patients had an RLS compared with 1 (3%) of 30 controls (p=0.012). Among 59 study subjects, RLS was associated with lower RA (81.9%±15.9% vs 98.5%±29.5%, p=0.030), RAA (84.7%±18% vs 105.6%±24.1%, p=0.022), LA (109.8%±18.6% vs 140.1%±33.7%, p=0.017) and LAA (median 102.9% (IQR 65.6%–121.7%) vs 229.1% (151.8%–337.5%], p=0.002) expansion indices and lower Qp/Qs ratio (0.91±0.06 vs 0.98±0.07, p=0.027).

Conclusions

This study suggests bi-atrial dysfunction in young adults with cryptogenic stroke, associated with moderate-to-severe RLS. Dysfunction of the atria and atrial appendages may be an additional mechanism for PFO-related stroke.

Trial registration number

NCT01934725.

Evidence of subtle left ventricular systolic dysfunction in cryptogenic stroke in the young

INTRODUCTION

Ischemic stroke in young patients often remains cryptogenic, that is, no underlying reason can be found. Some of these strokes may originate in the heart. Left ventricular (LV) dynamic volumetry and strain analysis are relatively new and promising methods for evaluating LV function.

METHODS

In this pilot study, we recruited 30 young (18-50 years) patients with cryptogenic ischemic stroke and 30 age- and sex-matched controls from the SECRETO study (NCT01934725). The LV systolic function was assessed by LV volumetry (ejection fraction, peak emptying rate, and time to peak emptying rate). The longitudinal systolic function was assessed by speckle tracking strain and strain rate imaging, and by tissue velocity imaging derived MAD (mitral annular displacement) and septal S'.

RESULTS

Stroke patients had less vigorous global longitudinal strain (median -18.9, interquartile range 3.3), compared to healthy controls (median -20.0, interquartile range 2.8), P = .010. There was no statistically significant differences in septal S', MAD, global longitudinal strain rate, or dynamic volumetry-derived parameters between the two groups.

CONCLUSIONS

Young cryptogenic stroke patients have subtly altered systolic function compared to healthy controls, found merely with longitudinal strain analysis. This infers that the heart may play a role in the pathogenesis of cryptogenic ischemic stroke.