The lowering of blood pressure after stroke

Angiotensin converting enzyme inhibitor and HMG-CoA reductase inhibitor as adjunct treatment for persons with HIV infection: a feasibility randomized trial

BACKGROUND

Treatments that reduce inflammation and cardiovascular disease (CVD) risk among individuals with HIV infection receiving effective antiretroviral therapy (ART) are needed.

DESIGN AND METHODS

We conducted a 2 × 2 factorial feasibility study of lisinopril (L) (10 mg daily) vs L-placebo in combination with pravastatin (P) (20 mg daily) vs P-placebo among participants receiving ART with undetectable HIV RNA levels, a Framingham 10 year risk score (FRS) ≥ 3%, and no indication for ACE-I or statin therapy. Tolerability and adherence were evaluated. Longitudinal mixed models assessed changes in blood pressure (BP), blood lipids, and inflammatory biomarkers from baseline through months 1 and 4.

RESULTS

Thirty-seven participants were randomized and 34 [lisinopril/pravastatin (n=9), lisinopril/P-placebo (n=8), L-placebo/pravastatin (n=9), L-placebo/P-placebo (n=8)] attended at least one follow-up visit. Participants were 97% male, 41% white, 67% were current smokers, and 65% were taking a protease inhibitor. Median age was 48 years, CD4 count 483 cells/mm(3), FRS 7.79%, total cholesterol 184 mg/dL, and LDL-C 95 mg/dL. There was no treatment difference for pravastatin vs P-placebo in total cholesterol, LDL-C, or any of the inflammatory biomarkers. Participants randomized to lisinopril vs. L-placebo had significant declines in diastolic BP (-3.3 mmHg, p=0.05), hsCRP (-0.61 µg/mL, p=0.02) and TNF-α (-0.17 pg/mL, p=0.04). Participants taking lisinopril vs L-placebo were more likely to report missed doses (88 vs 35%; p=0.001) and have adherence <90% by pill count (42 vs. 0%; p=0.02). Few participants from either group reported side effects (n=3 vs. n=1).

CONCLUSIONS

The modest BP changes and decreased adherence with lisinopril and absence of lipid differences with pravastatin suggest future studies of these drug classes should consider a run-in period to assess adherence and use a different statin. Our results also indicate that ACE-I therapy may have anti-inflammatory benefits for ART-treated persons with HIV infection and this should be further evaluated.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00982189.

Blood pressure lowering treatment for preventing stroke recurrence: a systematic review and meta-analysis

BACKGROUND

While hypertension is a leading risk factor for an initial stroke, the role of blood pressure lowering to prevent subsequent stroke is less clear. The results of recent large clinical trials investigating effects of antihypertensive agents in patients with a history of stroke have not shown a significant benefit; findings that are at odds with previous data. Our meta-analysis systematically evaluates the available, relevant trials to examine the role of antihypertensive drugs in preventing recurrent stroke.

METHODS

MEDLINE, CENTRAL, and ClinicalTrials.gov were systematically searched and bibliographies from key reports were examined. All randomized, placebo-controlled trials that tested blood pressure lowering agents in patients with stroke or transient ischemic attack were identified. The results from these trials were combined and meta-analyses were performed.

RESULTS

Ten studies were found to contain relevant endpoints and presented data allowing meta-analysis. Agents that lowered blood pressure reduced recurrent stroke (OR 0.71, 95% CI 0.59-0.86, P = 0.0004) and cardiovascular events (OR 0.69, 95% CI 0.57-0.85, P = 0.0004) in patients with a previous stroke or TIA. These agents did not affect the rate of myocardial infarction (OR 0.86, 95% CI 0.73-1.01, P = 0.07) or all-cause mortality (OR 0.95, 95% CI 0.83-1.07, P = 0.39) in this patient population.

CONCLUSION

Despite recent large trials showing no significant effect, in patients that have experienced a TIA or stroke, blood pressure lowering agents reduced the occurrence of subsequent stroke and cardiovascular events. The rate of myocardial infarction and all-cause mortality was unchanged.

Blutdruck und Gehirn

During acute cerebral infarction, autoregulation is abolished. Brain perfusion therefore directly depends on perfusion pressure and cardiac output. For this reason, in the early state of stroke, elevated blood pressure improves cerebral blood flow and only values of 210 mmHg systolic or above should be lowered. With the development of a vasogenic brain edema or a dysfunctional blood-brain barrier (usually on day 2 to 4 after infarction), blood pressure must be normalized in order to avoid hemorrhage and to minimize edema. In the presence of space occupying edema or intracranial hemorrhage, only those antihypertensive substances may be used which do not cause a dilatation of brain vessels. Direct vasodilators and calcium antagonists are not suitable in this situation. Furthermore, antihypertensive medication which causes bradycardia (e.g. beta blockers) should be avoided, because in acute stroke, brain perfusion also depends on the cardiac output. For primary and secondary stroke prevention normalization of blood pressure is essential. Efficacy is basically independent of the kind of antihypertensive medication used. Effective normalization of blood pressure probably helps to prevent vascular dementias of all kinds. Convincing studies however are still lacking for most sorts of antihypertensive medication.

The J-curve in hypertension

The J-curve debate has continued for 25 years. Dependency upon observational and retrospective studies has confused the issue; only the full publication of data from the prospective, randomized Hypertension Optimal Treatment (HOT) study has thrown genuine light on the problem. Many examples of the J-curve relationship between blood pressure and cardiovascular/noncardiovascular events are due to reverse causality, where underlying disease (eg, poor left ventricular function, poor general health, poorly compliant/stiff arteries) is the cause of both the low blood pressure and the increased risk of both cardiovascular and noncardiovascular events. The J-curve in patients with stiff arteries (wide pulse pressure) may be exacerbated by treatment. From the full publication of the HOT study database it is now reasonable to conclude that for nonischemic hypertensive subjects the therapeutic lowering of diastolic blood pressure (DBP) to the low 80s mm Hg is beneficial, but it is safe (though unproductive) to go lower. However, in the presence of coronary artery disease (limited coronary flow reserve) there is a J-curve relationship between treated DBP and myocardial infarction, but not for stroke. In such high-risk (for myocardial infarction) cases it would be prudent to avoid lowering DBP to below the low 80s mm Hg.

The Perindopril Protection Against Recurrent Stroke Study (PROGRESS): clinical implications for older patients with cerebrovascular disease

Blood pressure levels are strongly predictive of the risks of first-ever and recurrent stroke. The benefits of blood pressure-lowering therapy for the prevention of fatal and non-fatal stroke in middle-aged individuals are well established. However, until recently, there has been uncertainty about the consistency of such benefits across different patient groups and in particular, for older people and in those with a history of stroke. This paper discusses the evidence surrounding the effectiveness of blood pressure-lowering therapy, specifically in older patients with a history of stroke, with particular attention paid to the results from the Perindopril Protection Against Recurrent Stroke Study (PROGRESS). PROGRESS was a randomised, double-blind, placebo-controlled trial of 6105 individuals with a history of cerebrovascular disease recruited from 172 hospital outpatient clinics in ten countries. Participants (mean age 64 years; range 26-91 years) were randomly assigned to receive active treatment with an ACE inhibitor-based blood pressure-lowering regimen (perindopril) with or without addition of the diuretic indapamide, or matched placebo. At the end of follow up (mean of 4 years), active treatment reduced the incidence of total stroke by 28% (95% CI 17-38%) and the rate of major vascular events by 26% (95% CI 16-34%). Importantly, benefits of treatment were consistent across key patient subgroups, including those with and without hypertension, patients who were Asian and non-Asian, and for both ischaemic and haemorrhagic strokes subtypes. Current evidence is now strong for clinicians to consider blood pressure-lowering therapy as pivotal in the prevention of stroke, especially in patients with a known history of cerebrovascular disease (and vascular disease, in general), irrespective of blood pressure levels, as soon as patients are clinically stable after an acute stroke or other vascular event. Additional age-specific analyses of the PROGRESS data, together with those from other completed trials, will provide more reliable information about the size of the benefits of blood pressure-lowering therapy, specifically for different age groups, and particularly in the oldest old (those aged >80 years). In the meantime though, an ACE inhibitor plus diuretic treatment regimen that maximises the degree of blood pressure reduction has a good safety profile and is an effective treatment that should be considered in all patients with stroke, including the elderly.