A study of clinical & angiographic profile of patients with young stroke in tertiary care center of Southern Rajasthan

Introduction

A high frequency of strokes in young population has been reported by many authors in India and in other Asian countries as compared to west.^[1] Patients from India and South Asia were also younger than the patients with stroke in western countries.^[2] Understanding the exact etiology of stroke in the young has great relevance to its prevention and management. Recent development in the surgical and interventional therapy of extra cranial and intracranial vascular diseases have made it necessary to correctly identify the causative as well as contributory factors of stroke.

It is well established that incidence of risk factors and etiology in young adults differ notably from older patients. A modification in life style pattern has led to epidemic of traditional risk factors in younger population, and although large vessel extra and intracranial atherosclerotic disease, small-vessel atherosclerosis, and atrial fibrillation have a major role in cases of stroke in older adults, these disorders are comparatively less frequent in young adults.

Though many studies have been done about the association between various vascular risk factors and young stroke, very few studies from India have studied the angiographic profile in patients with young stroke. The study group of acute stroke in young patients in a tertiary care hospital provides an ideal population to comprehensively study the angiographic and clinical profile as they are comprehensively evaluated in stroke care unit.

Aims and Objectives

To study the Angiographic & Clinical profile of patients with ischemic stroke in the younger age group.

Materials and Methods

This cross sectional observational study was conducted on 310 patleast one standard vessel imaging procedure within 2 weeks of stroke onset. Study period Oct 2019 to Mar 2020.

Results

[Table 2] Shows clinical features and stroke severity. 18 patients (5.8%) had irregularity in pulse rate at presentation which provided an useful and direct clue to etiology at presentation. No patient presented in hypotension and BP was >140/90mm of Hg in 156 (50.3%) patients on presentation.

32 patients (10.3%) were noted to have a blood glucose level more than 200mg% on admission. No patient had hypoglycaemia on presentation.

Based on the clinical presentation patients were classified as right hemispheric/left hemispheric/ posterior circulation or undetermined territory. ([Table 3])

Clinical suspicion of left hemispheric strokes was noted in most of the patients and in about 20% presented with clinical picture suggestive of a posterior circulation involvement.

Cardio embolism was the second most frequent category of determined cause and when causes of cardioembolic strokes were further analyzed, majority of the strokes occurred in the setting of a rheumatic valvular heart disease (63.6%), with mitral valve disease being the most frequent association. Other aetiologies responsible for cardio embolism were paroxysmal AF, PFO and cardiomyopathies.

Discussion

While considering the ever increasing burden of stroke and the profound economic and social consequences in young population it is essential that etiological diagnosis and risk factor evaluation is complete. This helps not only in planning treatment and secondary prevention strategies but also assumes significance for rehabilitation.

The number of patients who were more than 35 years of age constituted almost 70% of the total patients. Also the gender differences were less prominent at younger age groups than in the older age groups. This is consistent with the previous studies some of which have described even higher incidence of stroke in females.^[3], ^[4] Of the commonly studied vascular risk factors hypertension, smoking, diabetes, dyslipidemia and CAD the risk factors most commonly noted were smoking and hypertension.

When the patients of <35 years and that of >35yrs of age were compared, the vascular risk factors revealed statistically significant (using Chi square test) higher occurrence of diabetes mellitus, hypertension, dyslipidemia and smoking in patients >35 years of age ([Table 2]).

Valvular heart disease was also noted in higher proportion of patients as compared to other studies and this may be because of referral bias as our hospital also serves as a major tertiary referral centre for cardiology services.

Anterior circulation strokes predominated in our study which was consistent with results from other young stroke studies. The proportion of left hemispheric strokes was higher than right as has been previously noted by many authors.^[4], ^[5] This may be because of the difficulty in identifying right hemispheric deficits. The strength of our study is that all patients underwent at least the basic etiologic work up in the form of ECG, ECHO and vessel imaging.

The commonest etiologic subtype according to TOAST etiological classification was stroke due to undetermined causes. The next common cause was stroke due to other determined causes. Similar findings were noted in a recent study by Dashetal^[6] in which 17.4% of their patients had stroke due to other determined causes, arterial dissection being the commonest. Similar trend was observed in our study also in where we noted arterial dissections in 16.7% of our patients. The higher proportion of patients in our study as well as in the study by Dashetal^[6] is probably related to increased and early availability of radiological investigations like CT angiogram.

This finding also highlights the importance of early and thorough evaluation of the vascular tree of all young stroke patients. Cardio embolic strokes were the next common cause. Valvular heart was the most common cause of cardio embolic strokes. Lipska et al^[7] have also previously noted cardio embolic strokes as the most common aetiology with valvular rheumatic heart diseases being the commonest cause for cardio embolic strokes. Various studies have previously reported the incidence of cardio embolic young strokes to be between 14-47%.^[8], ^[9], ^[10] However the common causes of cardio embolic strokes in studies from the west were congenital heart diseases like PFO/ ASD.

All patients underwent ECG and ECHO and this should be considered as one of the strengths of the current study. ECG provided a direct etiologic clue in about 6% of the patients whereas ECHO in about 20% of the patients. Holter was done in selected patients in whom the initial work up (Angiographic evaluation, ECG, ECHO) was negative and clinical suspicion of a cardio embolic aetiology was high. The yield of Holter was about 6 percent. Thus a thorough cardiac evaluation is necessary in all young stroke patients.

CT Brain was the most commonly used parenchymal imaging procedure and more than 40% of the patients underwent MRI as well as CT Brain. This underscores the difficulties in identifying infarcts in acute settings, especially in cases with posterior circulation strokes or acute on chronic infarcts. MRI as expected was more sensitive in detecting the posterior circulation strokes.^[11]

The most commonly performed angiographic procedure was CT angiogram followed by TOF MRA. The least commonly performed procedure was contrast enhanced MR angiography.

These findings highlight the easy availability, speed, good sensitivity and specificity of CT angiogram which has led to its widespread use in stroke setting. Contrast enhanced MRI was sparingly used and this probably reflects the limited resources.

Though DSA^[12], ^[13] Vasculitis Moya disease (especially when planning revascularization procedure), dissections and in acute settings when mechanical thrombectomy is planned.

More than 40% of the patients had normal vessel imaging and the abnormality which was most commonly identified was vessel occlusion. However vessel occlusion might not always provide a clue to the etiology of stroke.

Majority of the events were strokes of minor to moderate severity and of the 310 patients 8 patients expired during the hospital stay and less than 10% of patients had NIHSS >15 at discharge. This is consistent with most of the other young stroke studies from the western as well as the Indian literature. ^[6], ^[14], ^[15]

Conclusions

The high proportion of patients with past history of stroke/TIA highlights the need for better secondary prevention strategies. The conventional vascular risk factors shifts towards the ‘older population’ pattern after 35-50years of age and patients who are <35 years of age should be actively evaluated for even the rare causes of stroke in young. Arterial dissections are fairly common in young population and should be considered in appropriate clinical setting and all patients should have a good and timely angiographic assessment to rule out dissections. Thus, this study highlights the importance of risk factor evaluation, and control, complete etiological evaluation including angiographic assessment in the diagnosis, management and planning of secondary prevention strategies in young patients with stroke.

The main drawback is referral bias due to recruitment of patients from a referral institute. Also being a hospital based study admission bias is also one limitation. The fact that a very limited number of patients underwent a further detailed work up for rarer causes like prothrombotic states can also be considered as a limitation.

Source of Funding

No financial support was received for the work within this manuscript.

Conflicts of Interest

There are no conflicts of interest.