Fall in the Proportion of Atherothrombotic Strokes During the Last Decade

https://doi.org/10.1016/j.jstrokecerebrovasdis.2020.105257Get rights and content

Abstract

Objective

To determine the proportion of subtypes of ischemic strokes, vascular risk factors and treatment prior to stroke between 1997 and 2018 in a single institution in Argentina.

Methods

Demographics, risk factors, medications and TOAST subtypes were assessed and compared in ischemic stroke patients admitted during two periods of time, 1997-2007 (P1) and 2008-2018 (P2).

Results

There were 2747 patients (64% men, aged 67 ±15 years), 920 subjects in P1 and 1827 in P2. Age and gender distribution did not change over time. Proportion of large artery atherothrombotic strokes decreased from 29% in P1 to 14% in P2 (p <0.0001) and small vessel strokes from 15% to 11% (p <0.05). Cardioembolic and undetermined strokes increased from 17 to 25% (p <0.0001) and from 30% to 41% (p <0.0001), respectively. There were no changes in stroke of other etiologies (9% in both periods). Detection of atrial fibrillation increased from 14% to 19% (p<0.001). Use of medications prior to stroke increased for aspirin from 27% to 45% (p <0.0001), for antihypertensive drugs from 26% to 62% (p <0.0001), for statins from 14% to 42% (p<0.0001) and for anticoagulants from 4% to 9% (p<0.0001).

Conclusions

The proportion of strokes associated to large and small vessel atherosclerosis is declining in our population with an increase in the proportion of cardioembolic and undetermined strokes. Better management of risk factors and higher prevalence and/or better screening for atrial fibrillation could explain, at least in part, these findings.

Introduction

Etiologic subtypes of ischemic strokes (IS) are influenced by the vascular risk factors profile of patients.1, 2, 3, 4 Large artery atherosclerosis (LAA) strokes are related to dyslipidemia, hypertension, diabetes, prior transient ischemic attacks, smoking and male gender.1, 2, 3 Small vessel occlusion (SVO) strokes are strongly associated with hypertension and diabetes.2,5 Cardioembolic strokes are mostly caused by atrial fibrillation, valvular heart disease and ischemic heart disease.1, 2, 3

In recent years, there has been a substantial change in vascular risk factors definitions, including more strict and individualized criteria. Dyslipidemia targets depend on individual vascular risk rather than a fixed and universal cholesterol level.6 Hypertension definition also evolved over time. Since 1993 the JNC 5 lowered the target to 140/90 for all patients and to 130/80 mmHg for diabetics and/or chronic kidney disease subjects.7 Criteria for normal blood pressure have been set at even lower values recently.8 In addition to stricter definitions, there is a trend towards more intense vascular risk factors control, especially in developed countries.9,10 Better control of vascular risk factors could reflect greater adherence to primary and secondary prevention guidelines, greater availability of effective drugs, lower blood pressure and lipids targets, changes in lifestyle and more efficient public health policies. This scenario may lead to a lower proportion of atherothrombotic subtypes of IS, especially those secondary to large and small vessel disease. This phenomenon has recently been described in a Dutch cohort.11 The substantial drop in the number of carotid procedures performed in the United Stated between appears to support this presumption.12

The objective of this study was to determine the evolution in the proportion of the different subtypes of ischemic stroke, vascular risk factors profile and medical treatment prior to stroke in subjects admitted between 1997 and 2018 in a single institution in Argentina.

Section snippets

Materials and methods

We assessed patients older than 18 years admitted to our hospital with diagnosis of IS during a 22-year period. Most of our patients live in the city of Buenos Aires in upper-middle class neighborhoods and 72% of them have private health insurance or pay from their own pockets for health care. Clinical records of consecutive patients were evaluated between January 1st, 1997 and December 31th, 2018. We excluded patients with incomplete medical records and those with no follow-up after discharge.

Results

We studied a total of 2747 patients (64% men), aged 67 ± 15 years. There were 920 patients in P1 and 1827 in P2. The Table summarizes demographic data, vascular risk factors, previous medical treatment and IS etiological subtypes of total population and by periods. There were no differences in gender distribution and age between both periods.

There was a significant decrease in the proportion of LAA strokes from 29% in P1 to 14% in P2 (p <0.0001), SVO strokes proportion also decreased from 15%

Discussion

This report from a single institution in Argentina demonstrates a substantial decrease in the proportion of strokes associated with large and small vessel atherothrombosis between 1997 and 2018. LAA strokes decreased from 29% to 14% and SVO strokes from 15% to 11%. In addition, cardioembolic strokes mostly associated to AF, increased from 17% to 25% and undetermined strokes from 30% to 41%, with stable proportion of strokes due to other etiologies. In a context of stable prevalence of

Conclusion

Our study shows a robust trend for a decline in the proportion of IS associated to large and small vessel atherothrombosis. In the same period there was an increase in the proportion of cardioembolic strokes. Higher rates of use of preventive medical strategies leading to better control of hypertension and dyslipidemia in this population, and higher prevalence and/or better detection of AF, could explain, at least in part, these findings.

Acknowledgements

None.

Sources of funding

None.

Disclosures

Nothing to disclose.

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