Impairment of left atrial function and cryptogenic stroke: Potential insights in the pathophysiology of stroke in the young

Aditya Bhat; Shaun Khanna; Henry H Chen; Lina Lee; Gary C H Gan; Kazuaki Negishi; C Raina MacIntyre; Maria Carmo P Nunes; Timothy C Tan

doi:10.1016/j.ijcha.2019.100454

Impairment of left atrial function and cryptogenic stroke: Potential insights in the pathophysiology of stroke in the young

Int J Cardiol Heart Vasc. 2019 Dec 26:26:100454. doi: 10.1016/j.ijcha.2019.100454. eCollection 2020 Feb.

Authors

Aditya Bhat¹, Shaun Khanna¹, Henry H Chen¹, Lina Lee², Gary C H Gan¹, Kazuaki Negishi³, C Raina MacIntyre⁴, Maria Carmo P Nunes⁵, Timothy C Tan^{1

6}

Affiliations

¹ Department of Cardiology, Blacktown Hospital, Blacktown Road, Blacktown, NSW 2148, Australia.
² Geriatric Medicine, Rehabilitation & Aged Care Services, Blacktown Hospital, Blacktown Road, Blacktown, NSW 2148, Australia.
³ Nepean Hospital Clinical School, University of Sydney, Penrith, NSW, Australia.
⁴ Biosecurity Program, The Kirby Institute, Faculty of Medicine, University of New South Wales, Sydney, NSW 2052, Australia.
⁵ School of Medicine, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil.
⁶ Western Clinical School, Faculty of Medicine, University of Sydney, NSW 2145, Australia.

Abstract

Background: Stroke is one of the leading causes of morbidity and mortality with a significant percentage classified as cryptogenic. Left atrial (LA) remodelling, a substrate for atrial fibrillation (AF) and stroke development, may play a role in identification of the aetiology of cryptogenic stroke. We aimed to examine LA function to gain mechanistic insights into the pathophysiology of cryptogenic stroke in young patients otherwise at low risk for cardiovascular disease.

Methods: Patients aged <60 years without traditional cardiovascular risk factors and who were diagnosed with ischaemic cryptogenic stroke or TIA were evaluated and compared to healthy controls and patients with paroxysmal AF with a CHA₂DS₂-VA score of 0. Conventional and novel left ventricular (LV) and LA echocardiographic parameters between the three groups were assessed.

Results: Each group consisted of thirty patients. There were no significant differences in LV parameters (LVEF, LV endoGLS) between groups. LA strain in stroke patients was significantly lower compared to the controls (median 33%; interquartile range (IQ) [32/39] vs 31 [27/34]; p = 0.008). LA strain was significantly lower in AF patients compared to stroke patients (median 21% [19/22] vs 31% [27/34]; p < 0.0001).

Conclusion: A stepwise reduction in measures of LA function was appreciated between controls, young stroke and paroxysmal AF groups. This may indicate dynamic LA remodelling occurring in the young stroke population and suggest a shared causal mechanism for stroke development in this group. LA strain may further refine the risk for cardioembolic stroke.

Keywords: Atrial fibrillation; LA GLS, Left atrial global longitudinal strain; LA, Left atrial; LAEF, Left atrial ejection fraction; LV GLS, Left ventricular global longitudinal strain; LVEDD, Left ventricular end diastolic diameter; LVEF, Left ventricular ejection fraction; LVESD, Left ventricular end systolic diameter; Left atrial function; RA, Right atrial; RV, Right ventricle; RVSP, Right ventricular systolic pressure; Stroke; TAPSE, Tricuspid annular plane systolic excursion.