Strengthening the Secondary Prevention Line: Risk Assessment of Stroke Recurrence and Comprehensive Intervention Strategies for Blood Pressure and Thrombosis

Preventing stroke recurrence. The 5-year recurrence rate of stroke is approximately 30%, and the disability and mortality rates are higher than those of the first stroke. The first 6 months after a stroke are the period with the highest risk of recurrence. Secondary prevention should be initiated as early as possible after the first stroke, correcting all modifiable risk factors, such as hypertension, diabetes, dyslipidemia, heart disease, hyperhomocysteinemia, smoking, alcoholism, obesity, and depression.

Assessment of the pathogenesis of the first stroke. The pathophysiological mechanisms of ischemic stroke are mainly divided into four types: arteriosclerotic thrombotic infarction; cardioembolic stroke; lacunar infarction; and stroke of unknown cause. In clinical practice, ischemic stroke is mainly caused by arteriosclerotic thrombosis and lacunar infarction. It is important to note that strokes caused by atrial fibrillation and infective endocarditis require targeted treatment (warfarin and anti-infective drugs). To clarify the pathogenesis, the following laboratory tests may be considered: complete blood count, complete biochemistry panel, electrocardiogram, head CT scan, and carotid ultrasound.

Post-stroke blood pressure management. Hypertension is a closely related risk factor for stroke. Blood pressure levels above 160/100 mmHg significantly increase the risk of stroke recurrence. Recent studies have shown that approximately 80% of stroke patients in the early stages have hypertension, which is compensatory; only one-third of patients continue to have elevated blood pressure levels after their condition stabilizes. Excessive blood pressure reduction during the acute phase of stroke can lead to insufficient cerebral perfusion and leukoaraiosis, which are important underlying factors for post-stroke dementia. Therefore, blood pressure reduction should be gradual. Unless there are special circumstances such as hypertensive encephalopathy or aortic dissection, blood pressure should not be lowered too much or too quickly. Modify unhealthy lifestyle habits. Actively control hypertension; ideally, blood pressure should be lowered to <140/90 mmHg, if tolerated by the patient. Antihypertensive treatment should begin after the acute phase of stroke when the patient's condition has stabilized (generally 4 weeks after the stroke).

Antiplatelet aggregation. Antiplatelet drugs are recommended after ischemic stroke or TIA. Early use of aspirin can significantly reduce the risk of stroke recurrence. The combined use of aspirin and dipyridamole extended-release formulations is 100% more effective than using either drug alone, without increasing side effects such as bleeding. European and American stroke guidelines have listed it as a first-line drug. Based on evidence from the CHARISMA and ESPIRIT studies, the following recommendations are made for patients with atherosclerotic stroke or TIA: Compound aspirin/dipyridamole extended-release formulations (12.5mg/100mg-25mg/200mg (tablets or capsules), twice daily); clopidogrel (75mg/day) can be used for those who are eligible, high-risk individuals, or those who cannot tolerate aspirin; aspirin alone is used at a dose of 75-150mg/day, taken once daily.

Anticoagulation therapy. The use of anticoagulants increases the risk of intracranial hemorrhage and is only suitable for patients diagnosed with cardioembolic events caused by atrial fibrillation (especially non-valvular atrial fibrillation). Excessive anticoagulation is not safe. Warfarin anticoagulation therapy is recommended at a dose of 2–4 mg/day, with an INR of 2.0–3.0. If INR monitoring is not possible, warfarin should not be used; antiplatelet therapy should be chosen instead.

Intervention for cardiac diseases. Except for patients with atrial fibrillation-induced cardioembolic stroke who require aggressive and appropriate anticoagulation measures, other underlying heart diseases significantly increase the risk of recurrent embolic stroke. Therefore, it is recommended to actively treat the primary disease according to its cause. Myocardial infarction is a risk factor closely related to stroke occurrence and recurrence; it should be actively managed, maintaining cardiac output, and administered with beta-blockers, statins, and ACEI/ARB preparations. This can reduce stroke risk while preventing recurrent myocardial infarction. Infective endocarditis can produce emboli and is treated with antibiotics, without the need for anticoagulation.

Intervention for carotid artery stenosis. Mild to moderate carotid artery stenosis with symptoms (TIA or minor stroke) should be treated conservatively with medical intervention first. Asymptomatic carotid artery stenosis requires more careful management. If hypertension is present, close monitoring is necessary for antihypertensive treatment of carotid artery stenosis patients. Based on the patient's response to treatment, generally, for unilateral carotid artery stenosis >70%, the blood pressure should not be lowered below 130/70 mmHg; for bilateral carotid artery stenosis >70%, the blood pressure should not be lowered below 150/70 mmHg.

Intervention in transient ischemic attacks (TIAs). TIAs are often a precursor to a complete stroke or a second stroke, and a complete stroke is very likely to occur within two weeks. Therefore, identifying and treating the cause of a TIA and taking proactive measures are crucial for preventing a second, more severe stroke. Multiple risk factors, including hypertension, hemodynamic abnormalities, smoking, excessive alcohol consumption, hyperlipidemia, and arterial stenosis, should be actively addressed, and aggressive systemic therapy, such as antiplatelet therapy, should be administered.

Post-stroke management of blood lipids and blood glucose. Emphasis is placed on the use of statins. Based on evidence from the SPARCL study, intensive lipid-lowering therapy is recommended for patients with atherosclerotic stroke or TIA. Statins can stabilize atherosclerotic plaques, inhibit plaque surface inflammation, and inhibit platelet aggregation; therefore, they should be taken long-term. Evidence-based medicine has shown that they can reduce the risk of stroke by 20%–30%. The short-term effect of blood glucose control on preventing stroke recurrence has not yet been confirmed. However, treating diabetes is crucial for controlling other risk factors such as hypertension, hyperlipidemia, atherosclerosis, and kidney damage, and has long-term benefits for stroke recurrence prevention; therefore, it must be actively treated. Two-thirds of patients with cardiovascular and cerebrovascular diseases have diabetes or prediabetes, and blood glucose and glucose tolerance tests must be performed.