Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 50, Num. s1, 2002, pp. S2-S7

Neurology India, Vol. 50, (Suppl. 1), Dec, 2002, pp. S2-S7

Stroke in India - Issues in Primary and Secondary Prevention

P. M. Dalal

Stroke Unit and ICASS Research Cell, Lilavati Hospital and LKMM Trust Research Centre, Ali Yavar Jung, Mumbai - 400 050, India.
Correspondence to : Dr. P.M. Dalal, Municipal Building No. 3, Flat 18, Clerk Road, Haji Ali, Mumbai - 400 034, India.

Code Number: ni02156

Summary

India will face an enormous socio-economic burden to meet the costs of rehabilitation of stroke victims because the population is now surviving through peak years (age 55-65) of occurrence of stroke or cerebrovascular disease (CVD). Recent community surveys from many regions of India show a crude prevalence rate for strokes presumed to be of vascular origin in the range of 200 per 100,000 persons. Major risk factors identified in India are hypertension (> 95 mmHg diastolic), hyperglycemia, tobacco use (smoking/chewing) and low normal haemoglobin levels (< 10 gm%).A public awareness campaign focussing on the control of stroke risk factors, along with governmental support to implement a national health policy for screening high risk population in a cost effective manner, is highly recommended.

Key words : Stroke, Prevention, India.

Introduction

India will face an enormous socio-economic burden to meet the costs of rehabilitation of stroke victims because the population is now surviving through peak years (age 55-65) of occurrence of stroke or cerebrovascular disease(CVD). However, for strokeprevention planning, reliable epidemiological information on annual incidence or prevalence rates and morbidity or mortality trends for CVD in defined populations are not available. Recent community surveys from many regions of India show a crude prevalence rate for strokes presumed to be of vascular origin in the range of 200 per 100,000 persons (Table 1),¹ but there are numerous difficulties in validation of stroke diagnosis in these registries. Therefore, several prospective studies were initiated with well-defined protocols to identify etiopathology, risk factors (RFs) and morbidity / mortality trends at a community hospital in Mumbai, serving a nearby relatively stable populations.

Material and Methods

Terminologies as defined in the International Classification of Diseases have been adopted. Comprehensive designs of these studies, giving definitions, clinico-pathological correlations, pan-cerebral angiographic and necropsy findings, have been reported elsewhere.^2-4 A stroke data bank has been established. All data have been encoded for future reference.

Results

Based on pan-cerebral angiographic and necropsy findings of the first study,^2,3 it was possible to confirm that extracranial athero-lesions were chiefly responsible for thrombotic brain infarction, whereas intracranial lesions were documented in cerebral embolism cases; advancing age, hypertension and large cerebral infarcts carried grave prognoses. In an International Collaborative Study on the distribution of athero lesions, in 1090 circle of Willis (medicolegal and non medico- legal autopsies), it was found that athero-lesions began at an early age (<10years) and. severity of lesions progressed with advancing age, similar to what was reported in Minnesota (USA) and Fukuoka (Japan) centres.⁵ In the second prospective study in 704 consecutive patients having had a recent stroke, as verified by supportive / diagnostic tests, the general data by age and sex and survival status are shown in Table II.⁴ Comparing the two prospective CVD reports having identical methodologies and referral/observer bias, during the period 1963-68 and 1978-82, a significant drop was recorded in case fatality rate (32%-12%) thereby resulting in higher survival (68%-88%). These changing trends in morbidity/mortality patterns have now posed a major socio-economic challenge in rehabilitation of 'stroke-survivors'.⁴ In a subsequent multicentric prospective case-control study on risk factors in ischemic strokes, hypertension (> 95 mmHg diastolic), hyperglycemia, tobacco use (smoking / chewing) and low normal haemoglobin levels (< 10 gm%) were important risk factors (Table III).^6-7

Concluding Remarks

For India where its people are surviving through the peak years of stroke occurrence, preventive strategies are mandatory. Available data indicate that CVD occurs at all ages in both sexes and with increasing frequency in advancing age (Table I). From case-control data on risk factors, it appears that hypertension; diabetes mellitus, low normal haemoglobin and tobacco use (smoking / chewing) are important risk factors.

Thus to design stroke prevention strategies, public awareness and health education on warning symptoms of hypertension and strokes by optimum use of existing mass media is vital. Life style changes, dietary habits and intensive campaign against tobacco use will prove rewarding. Primary health care teams should receive training on nomenclature and clinical diagnosis, in the absence of CT facilities in rural and remote areas. Mass screening surveys to identify 'hypertensives' and 'stroke - prone' subjects, wherever feasible, should be undertaken to prescribe simple, practical, non-costly remedies. The patients' compliance to clinic reference is usually unsatisfactory; hence, a cadre of medico-social/ multipurpose workers to remain in constant contact with such 'stroke-prone' individuals will have to be established to ensure regular intake of medicines and control of risk factors. National Councils to liaise between various agencies (health, industry, finance etc.) are essential to coordinate actions at all levels. The political will to legislate National Health Policy in support of above objectives is highly recommended.^8-9

References

1. Dalal PM : Community survey of hypertension in 'old' Bombay. In : Essential hypertension. Symposia Specialists, Thurm RH (ed.). Miami 1979; 35-41.
2. Dalal PM, Shah PM, Aiyar RR et al : Cerebrovascular diseases in west-central India. BMJ 1968; 3 : 769-774.
3. Dalal PM, Shah PM, Aiyar RR : Arteriographic study of cerebral embolism. Lancet 1965; 2 : 358-361.
4. Dalal PM, Dalal KP, Vyas AC : Strokes in the young population in west-central India - some observations on changing trends in morbidity and mortality.J Neuropeidemiology 1989; 8 : 160-164.
5. Dalal PM, Sheth SC, Deshpande CK et al : Intracranial cerebral athero-sclerosis in Bombay (India) and Minneapolis (USA). Indian J Med Res 1973; 23 : 21-26.
6. Dalal PM, Dalal KP, Rao SV et al : Strokes in west-central India: a prospective case-control study of 'risk factors' (a problem of developing countries). In : Neurology in Europe. Artko D et al (eds.). John Libbey and Co. Ltd, London. 1989; 16-20.
7. Dalal PM : Low haemoglobin levels as a 'risk factor' in cerebral infarction (abstract). Stroke 1989; 20 : 157.
8. Dalal PM : Strokes in the elderly : Prevalence, risk factors and the strategies for prevention. Indian J Med Res 1997; 106 : 325-332.
9. Dalal PM : Strokes in India : Issues in primary and secondary prevention. J Stroke Cerebrovascular Disease 1999; 9(2) : 13-17.

Suggested Reading

Stroke Prevention (Secondary)

General / Stroke mortality trends

1. Vermulant EGJ : Effect of homocysteine lowering treatment with folic acid plus vitamin B6 on progression of subclinical atherosclerosis: A randomized placebo controlled trial. Lancet 2000; 355 (9203) : 517-522.
2. Chambers JC, Seddon MDI, Shah S et al : Homocysteine : A novel risk factor for vascular disease. J R Soc Med 2001; 94 : 10-13.
3. Dalal PM : Editorial: Stroke prevention strategies for India. Stroke (Indian Edition) 2001; 1(1) :1.
4. Gillum RF : New consideration in analyzing stroke and heart disease mortality trends. Stroke 2002; 33 : 1717-1722.
5. Keswani SC, Chauhan N : Antiphospholipid syndrome. J R Soc Med 2002; 95 : 336-342.

Blood Pressure

1. Bath F, Bath P : Blood pressure in acute stroke collaboration. Cerbrovasc Dis 1997; 7 : 205-213.
2. Klungel OH, Kaplan RC, Heckbert SR et al : Control of blood pressure and risk of stroke among pharmacologically treated hypertensive patients. Stroke 2000; 31 : 420.
3. Otterstad JE, Sleight P : The HOPE study: Comparison with other trials of secondary prevention. European Heart Journal 2001; 22 : 1307-1310.
4. Schroder J, Luder S : Preventing stroke: Highrisk patients should receive ramipril irrespective of their blood pressure. BMJ 2002; 324 : 687- 688.

Antiplatelet / Antithrombotic therapy in Stroke Prevention

1. Antiplatelet Trialist's Collaboration. Collaborative overview of randomised trials of antiplatelet therapy. I: Prevention of death, myocardial infarction and stroke by prolonged anti-platelet therapy in various categories of patients. BMJ 1994; 308 : 81-106.
2. International Stroke Trial Collaborative Group (IST) : A randomised trial of aspirin, heparin, both or neither among 19,435 patients with acute ischaemic stroke. Lancet 1997; 349 : 1569-1581.
3. Hankey GJ, Sudlow CLM, Dunbabin DW : Thienopyridines or Aspirin to prevent stroke and other serious vascular events in patients at high risk of vascular disease? A systematic review of the evidence from randomized trials. Stroke 2000; 31(7) : 1779.
4. Antithrombotic Trialists' Collaboration. Collaborative meta-analysis of randomised trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients. BMJ 2002; 324 (7329) : 71-86.

Anticoagulant treatment

1. Atrial Fibrillation Investigators. Risk factors for stroke and efficacy of antithrombotic therapy in atrial fibrillation: Analysis of pooled data from five randomized controlled trials. Arch Intern Med 1994; 154 : 1449-1457.
2. Yamaguchi T : Optimal intensity of warfarin therapy for secondary prevention of stroke in patients with nonvalvular atrial fibrillation : A multicenter, prospective, randomized trial. Stroke 2000; 31(4) : 817.
3. Mohr JP, Warfarin-Aspirin Recurrent Stroke Study Group. A comparison of warfarin and aspirin for the prevention of recurrent ischaemic stroke. N Engl J Med 2001; 345(20) : 1444- 1451.
4. Hankey GJ : Warfarin-Aspirin recurrent Stroke Study (WARSS) Trial: Is Warfarin really a reasonable therapeutic alternative to aspirin for preventing recurrent noncardioembolic ischemic stroke? Stroke 2002; 33 : 1723-1726.

Neuroprotective Agents

1. Furlan AJ : Acute stroke trials : Strengthening the underpowered. Stroke 2002; 33 : 1450-1451.

Role of Surgery or Angioplasty in Carotid Stenosis

1. North American Symptomatic Carotid Endarterectomy Trial (NASCET) Collaborators. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. N Engl J Med 1998; 339(20) :1415-1425.
2. Randomised trial of endarterectomy for recently symptomatic carotid stenosis : final results the MRC European carotid surgery trial. Lancet 1998; 351 : 1379-1387.
3. Benavente O, Moher D, Pham B : Carotid endarterectomy for asymptomatic carotid stenosis: a meta-analysis. BMJ 1998; 317 : 1477- 1480.
4. Rothwell PM, Warlow CP : Prediction of benefit from carotid endarterectomy in individual patients: a risk modeling study. Lancet 1999; 353 : 2105-2110.
5. CAVATAS Investigators. Endovascular versus surgical treatment in patients with carotid stenosis in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS) : A randomized trial. Lancet 2001; 357 : 1729-1737.
6. Earnshaw JJ : Carotid endarterectomy: the evidence. J R Soc Med 2002; 95 : 168-170.

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