Blood pressure and low-density lipoprotein-cholesterol lowering for prevention of strokes and cognitive decline: a review of available trial evidence.

BACKGROUND AND OBJECTIVES: It is well established by a large number of randomized controlled trials that lowering blood pressure (BP) and low-density lipoprotein cholesterol (LDL-C) by drugs are powerful means to reduce stroke incidence, but the optimal BP and LDL-C levels to be achieved are largely uncertain. Concerning BP targets, two hypotheses are being confronted: first, the lower the BP, the better the treatment outcome, and second, the hypothesis that too low BP values are accompanied by a lower benefit and even higher risk. It is also unknown whether BP lowering and LDL-C lowering have additive beneficial effects for the primary and secondary prevention of stroke, and whether these treatments can prevent cognitive decline after stroke. RESULTS: A review of existing data from randomized controlled trials confirms that solid evidence on optimal BP and LDL-C targets is missing, possible interactions between BP and LDL-C lowering treatments have never been directly investigated, and evidence in favour of a beneficial effect of BP or LDL-C lowering on cognitive decline is, at best, very weak. CONCLUSION: A new, large randomized controlled trial is needed to determine the optimal level of BP and LDL-C for the prevention of recurrent stroke and cognitive decline.

Blood pressure and LDL-cholesterol targets for prevention of recurrent strokes and cognitive decline in the hypertensive patient: design of the European Society of Hypertension-Chinese Hypertension League Stroke in Hypertension Optimal Treatment randomized trial.

BACKGROUND AND OBJECTIVES: The SBP values to be achieved by antihypertensive therapy in order to maximize reduction of cardiovascular outcomes are unknown; neither is it clear whether in patients with a previous cardiovascular event, the optimal values are lower than in the low-to-moderate risk hypertensive patients, or a more cautious blood pressure (BP) reduction should be obtained. Because of the uncertainty whether 'the lower the better' or the 'J-curve' hypothesis is correct, the European Society of Hypertension and the Chinese Hypertension League have promoted a randomized trial comparing antihypertensive treatment strategies aiming at three different SBP targets in hypertensive patients with a recent stroke or transient ischaemic attack. As the optimal level of low-density lipoprotein cholesterol (LDL-C) level is also unknown in these patients, LDL-C-lowering has been included in the design. PROTOCOL DESIGN: The European Society of Hypertension-Chinese Hypertension League Stroke in Hypertension Optimal Treatment trial is a prospective multinational, randomized trial with a 3 × 2 factorial design comparing: three different SBP targets (1, <145-135; 2, <135-125; 3, <125  mmHg); two different LDL-C targets (target A, 2.8-1.8; target B, <1.8  mmol/l). The trial is to be conducted on 7500 patients aged at least 65 years (2500 in Europe, 5000 in China) with hypertension and a stroke or transient ischaemic attack 1-6 months before randomization. Antihypertensive and statin treatments will be initiated or modified using suitable registered agents chosen by the investigators, in order to maintain patients within the randomized SBP and LDL-C windows. All patients will be followed up every 3 months for BP and every 6 months for LDL-C. Ambulatory BP will be measured yearly. OUTCOMES: Primary outcome is time to stroke (fatal and non-fatal). Important secondary outcomes are: time to first major cardiovascular event; cognitive decline (Montreal Cognitive Assessment) and dementia. All major outcomes will be adjudicated by committees blind to randomized allocation. A Data and Safety Monitoring Board has open access to data and can recommend trial interruption for safety. SAMPLE SIZE CALCULATION: It has been calculated that 925 patients would reach the primary outcome after a mean 4-year follow-up, and this should provide at least 80% power to detect a 25% stroke difference between SBP targets and a 20% difference between LDL-C targets.

Stroke research in China.

China reports more patients with stroke than anywhere else in the world. While there is still a great deal of unknown information, stroke research has been making great progress in recent years. This study will review and discuss a variety of factors such as clinical research, population and genetic epidemiology, brain ischemia/reperfusion exploring, leukoencephalopathy (CADASIL), neural stem cell and stroke, neuroprotective treatment for stroke, clinical therapy test in stroke, rehabilitation and prevention. Cities and towns in China have good integrated systems for registering and investigating strokes. Chinese researchers have followed closely the international level of stroke treatment with a forward position in neural stem cell. Traditional Chinese drugs have featured effects on neuroprotective treatment for stroke which has also been investigated. Chinese scientists suggested a new way of dividing neuroprotectors in stroke. The clinical therapy test with urokinase and defibrase for cerebral infarction in China is effective and relatively safe, yet the original papers published by Chinese researchers and clinical effects for patient treatment still need to be improved and updated.

[Evolution of the definition of transient ischemic attack (TIA).]

The definition of TIA began with one-hour cutoff in 1950s and established with 24-hours cutoff during 1960s and 1970s. During the period when no imaging techniques could help to differentiate TIA from ischemic stroke, such definition could only contribute to clinical classification, with inevitable shortcomings. With the development of imaging technique and thrombolysis therapy, TIA has become a good opportunity for identifying and managing ischemic cerebrovascular diseases. The New TIA definition employs the one-hour cutoff with emphasis on no brain lesion evidence. The new definition may help to identify and manage ischemic cerebrovascular diseases earlier. Revision of the definition of diseases calls for the combination of the development of medical science and clinical practice.