Relationship between Control of Blood Pressure Levels and Stroke among the Elderly - Research Proposal Example

Relationship between Control of Blood Pressure Levels and Stroke among the Elderly Student‘s Name: Instructor’s Name: Institution: Date: Relationship between Control of Blood Pressure Levels and Stroke among the Elderly Introduction It is widely known that suffering from high blood pressure predisposes a person to a high risk of suffering from cardiovascular diseases for instance heart attacks, ischaemic heart disease, and stroke. The research on effects of blood-pressure lowering drugs and in particular β-blockers and diuretics has been carried for period of time back from the early 1990s. Such research results have in most cases been derived from Randomized Controlled Trials involving more than 50, 000 hypertensive patients. On the other hand, some researchers have gone to the extent of conducting systematic reviews (meta-analysis) of Randomized Controlled Trials and established that significant reduction of blood pressures ranging from 10 to 12 mm HG and form 5 to 6 mm HG in both systolic and diastolic patients. These reductions are said to have resulted in reduction of the risk of suffering from stroke especially among the elderly as well as prevalence of coronary heart diseases. In this regard, a lot of concern among medical researchers has increased in leaps and bounds due to the increase in cases of cardiovascular diseases. In particular, this is being observed among the elderly who suffers from terminal diseases especially diabetes. Other than diabetes itself, majority of the elderly suffers from high blood pressure as they get older. In this regard, other opportunity diseases especially stroke affects individual who are not capable of properly controlling their blood pressure. Therefore, the purpose of this research essay is to critically evaluate if there is any effect of controlling blood pressure in reducing chances of contracting stroke and if there is, to what extent it is effective. To carry out an evaluation on this research question, a literature based research on various scholarly journal articles is done in this research essay. Besides, it summarizes four scholarly journal articles and then they are appraised from a critical perspective to prove their relevance. Subsequently, the four journal articles are evaluated to establish the usefulness of their study design. Finally, implications of the research outcomes with respect to the four articles are focused vis-à-vis application of such findings in today’s clinical research. Summary of the Journal Articles Chinese Trial on Isolated Systolic Hypertension in the Elderly Wang et al. (2000) in their research study focused on determining whether or not anti-hypertensive medication could significantly reduce the prevalence of fatal and non-fatal stroke among the elderly in China. In particular, the patients of interest in the research study were those who suffered from Isolated Systolic Hypertension. In this study, the main objectives included: if benefits accrued from active treatment were enjoyed similarly by patients who had been categorized into four strata based on their sex and historical cardiovascular-related complications; to determine whether or not mortality and morbidity results were dependent on age, drinking or smoking habits, level of diastolic or systolic blood pressure, and/or diabetes mellitus. The researcher used patients who were aged at least 60 years ‘with a sitting systolic BP of 160 to 219 mmHg and diastolic BP less than 95mmHg’ (Wang et al, 2000, P.211). The groups of patients in the research study were stratified based on their location, gender, and historical cardiovascular complications. Out of this, 1253 were subjected to active nitrendipine (10-40mgld) treatment with probable parallel treatment using hydrochlorothiazide (12.5-50mgld) and captopril (12.5-50.0mgld). Besides, the researchers used another group of patients, 1141, as a control but they were as well administered with the medication. On successfully completing their research study, Wang et al. (2000) found out that male sex, past cardiovascular complications, lower diastolic BP or higher systolic BP, older age, residing in Northern china, diabetes mellitus, and smoking or drinking had significant and independent effect of increasing the following; cardiovascular endpoints, all form of strokes, as well as all cardiac end-points. However, among the control patients, diabetes was found to increase the risk of all the end-points in the range of two-to-three fold. Nevertheless, it was found out that being under active treatment of the anti-hypertensive drugs reduced the excess risk associated with diabetes to a low level safe for cardiovascular mortality. In this regard, the authors concluded that among the elderly Chinese patients suffers from isolated systolic hypertension; gradual antihypertensive drug treatment had significantly impact on improving prognosis. This is especially in diabetic patients although cardiac end-points were large among the non-smokers. Nevertheless, active treatment did not at any instances depend on characteristics of individuals in the enrollment. Prevention of Cardiovascular Events by Treating Hypertension in Older Adults: An Evidence-Based Approach In another research article by Firdaus et al. (2008), a review based research was carried out to ascertain if there exists any significant benefit by lowering and /or controlling the level of blood pressure among the elderly who are hypertensive. The basis of this research review article is on the fact that the prevalence of hypertension in the United States of America is present in more than 10 million men and about 17 million women. The authors note that isolated systolic Hypertension is more prevalent compared to systolic/diastolic hypertension among the elderly. In their study, Firdaus et al. (2008) did research at pub med based on key terms such as hypertension classification, diet therapy and drug therapy among others. Search results totaled to 26,029 and after being limited to human beings aged between 65 and 80 years old, some 676 articles relevant to the topic were found. All the articles were reviewed but included 8 Randomized Controlled Trialss and 2 meta-analyses. In one of the review article, the Firdaus et al. (2008) evaluated the benefits of lowering Blood pressure among aged between 65-79 years. After carrying out meta-analysis, it was found that there is an average reduction of between 12 to 13mmHg in systolic blood pressure and this was correlated to 21% reduction in coronary artery diseases, 37% reduction in stroke, a 25% reduction in cardiovascular mortality, and 13% reduction in all-cause mortality. Subsequently, a Meta -analysis of the research results was also done for people aged between 80 years and older. This aimed at establishing if they have any benefits from lower blood pressure. However the authors note that most of the medical experts perceive antihypertensive treatment to be less effective among hypertensive patients above 80 years. Nevertheless research has shown that antihyptensive theory significantly reduces the risks of non- fatal cardiovascular events, and in particular stroke by 36% (Firdaus et al. 2008, p22) However there was no appreciable effect in regard to cardiovascular mortality that was established. In this respect , the authors noted that much of the research work done demonstrates tangible evidence that lowering blood pressure levels with antihypertensive drugs among the adults reduces the risks of cardiovascular diseases for instance stroke. Therefore, ‘low -dose diuretics should be considered the most appropriative first- step treatment for preventing cardiovascular morbidity and mortality’ ( Firdaus et al 2008, p 219). Blood Pressure Reduction and Secondary Prevention of Stroke and Other Vascular Events: A Systematic Review Subsequently in a third article by Rashid et al (2003) a research study was carried out based on the notion that high blood pressure as predisposing factor for one to suffer from stroke . Therefore, the main objective was to evaluate ‘the effectiveness of reducing blood pressure levels in preventing recurrent events in patients with previous stroke or transient ischemic attack’ (Rashid et al., 2003, p. 27420). In this regard, the authors carried out systematic review and meta-analysis of completed randomized controlled trials that examined effects of blood pressure levels on recurrent vascular events among patients with previous hemorrhagic or ischemic stroke or transient ischemic attack. Clinical trials were searched electronic databases for instance, MELINE, in which seven were randomized controls whereas comparison groups amounted to eight. In this systematic review, it was found out that treating hypertension and or lowering blood pressure levels by 63% non- fatal stroke by 65%, myocardial information by 63%, and overall vascular vents by 66%. Nevertheless there was no appreciable effect that was found with respect to all cause or vascular mortality. Heterogeneous results were found on several instances but they were more or lesser extent attribute to the kind of antihypertensive drugs administered. For instance, angiotensin-converting enzyme inhibitors and diuretics separately and or both are known to reduce vascular events whereas on the other hand B- receptor antagonistic had no significant effects. The authors correlated the reduction in stroke prevalence to the variation M systolic blood pressure between treatment and control groups. In this regard Rashid et al. (2003), notes that there exists tangible evidence from randomized controlled clinical trials in support of using antihypertensive drugs to lower blood pressure. This comes in handy at preventing vascular events among patients with past stroke complications or transient ischemic attack. Thus they cardiovascular disease prevention can be correlated positively with the extent to which blood pressure levels are reduced. Treatment of Hypertension in Patients 80 Years of Age or Older In another research study by Beckett et al (2008), it is argued that for the past few decades there has been no clear information regarding benefits accruing to hypertension patients over 80 years of age upon being treated. On these basis, the authors note that one of the major suggestions has been that anti- hypertensive therapy are capable of reducing the risk of stroke although it may as well increase the risk of death. In this regard, Beckett et al (2008) identified about 3845 patients from Tunisia, Australia, China and Europe who were at least 80 yrs of age and had a sustained blood pressure of at least 160 mm Hg. These patients we administered the ‘diuretic indapamide (sustained release, 1.5 mg) or matching placebo’ (Beckett et al. 2008, p 1887). In addition, ‘angiotensin-converting enzyme inhibitor perindopril (2 or 4 mg), or matching placebo was added if necessary to achieve the target blood pressure of 150/80 mmHg’. The basic end point was that a patient was suffering from either fatal or non fatal stroke. After successfully carrying out the research, it was found out that 1933 patients who were actively receiving treatment plus 1912 patients in the placebo group and a mean age of 83.6 years, mean blood pressure of 173.0/90.8 mm Hg while sitting , and 11.8% of them had history of cardiovascular complications. However, the patients under investigations were followed up in an average of 1.8 years. After about two years, it was established that mean blood pressure was 15.0/6.1mm Hg while sitting, among the group of patients receiving active- treatment compared to the placebo group. Subsequently in an intention to-treat analysis ,the active treatment was correlated to a 30% reduction in the prevalence rates of either fatal or non- fatal stroke, a 39% reduction in the prevalence rates of either the fatal or non-fatal stroke, a 9% reduction in the rate of deaths caused by stroke, a 21% reduction in the rates of death caused by cardiovascular diseases and 64% reduction in the rates of heart failure (Beckett et.al 2008, p. 1887). However, there were very few serious adverse events reported among the active-treatment group i.e. 358 active treatment group versus 448 placebo groups patients. In this respect, Beckett et.al 2008 established that antihypertensive treatment coupled with indapamide, with or without perindopril among persons aged 80 years and above is significantly beneficial. Hence they note that it facilitates reduction in the number of deaths caused by stroke regardless of the geographical location. Critical Appraisal Author/ journal Weng et al 2000 Purpose/significance Main objective of the study was to establish whether there were any benefits resulting from active antihypertensive treatment among individuals who were categorized on the basis of sex and cardiovascular complications. In addition, effects of smoking/drinking, diabetes mellitus, and level of diastolic and systolic blood pressure levels were also evaluated. This was based on the fundamental concept that such treatments results in reducing the rate of stroke by 38% per 1000 patients per year. Methods The study was designed as an intention – to- treat analysis of the Syst-China trial. Patients aged 60 years and above were enrolled. Their sitting systolic BP ranged from 160 to 219mmHg but diastolic Bp was below 95mmHg. 31 Syst-China centers were established and each received supplies of three active – study drugs and three matching placebos. The patients were stratified into four strata and each received medication of the respective drugs whilst being under observation. Fatal and non-fatal stroke were the basic endpoints whereas secondary endpoints were in accordance to Syst-Eur trial. Symptoms and conditions of these were endpoints were clinically diagnosed for a period and the various causes of death such as myocardial infarction, were recorded. Other variables included factors such as smoking and diabetes mellitus. The data obtained was analyzed using 2 –sided tests while applying commercial software such as version.. SAS version 6.12. Besides means and proportions were compared and contrasted using Z test and the X2 statistic. Single and multiple Cox regressions were applied in evaluating relative hazard rates whereas survival curves were evaluated using long rank test. Results In the final simple, none of research subjects totaled to 2892 and 3510 in the placebo and active treatment groups respectively. After 2 years of observation, sitting systolic and diastolic Bp reduced by a mean (ISD) of 11+ 17 mmHg and 2 + 8 mmHg, respectively in the placebo group and by 20+16 mmHg and 5+ mmHg respectively in the active treatment group. Statistically the diastolic and systolic Bp levels between the study groups resulted in an average of 3.2mmHg (95% CI, 2.4 – 4.0) and 9.1 mmHg (95% CI, 2.4 -4.0) and 9.1mmHg (95% CI 7.6 – 10.7mmHg). Besides, it was established that there was reduction in incidence of mortality (PLO.PI) fatal and non-fatal stroke (PL).05) and total cardiovascular endpoints (PLO.01) Discussion It was established that male sex was a determinant factor for all the endpoints and that benefits of active antihypertensive treatment was experienced similarly across the four strata. Age was a significant predictor of all the endpoints except for stroke. However, there was no statistical difference when the patients we compared in regard to their place of origin (Southern and Northern China) (P = 0.92). Smoking/drinking was a major determinant in increasing the rate of both fatal and non-fatal stroke rates. Finally, Diabetes mellitus was found to be a major determinant of all the endpoints especially in the placebo group whereas in the active treatment group risks correlated to diabetes were reduced significantly for fatal mortality and combined non fatal endpoints (hazard rates were 0.78 to 2.03). This research suggests that hypertensive diabetic patients who are first treated using dihydropyridine calcium blocker may better off be protected from cardiovascular diseases as compared to those started with thiazide. Strengths and weaknesses This research study focused more on historical cardiovascular complications and the male sex as being important risk factors. Therefore, stratification based on these traits necessitated to establish whether there were similar effects among the four strata. However, the inclusion of a large number of male sex individuals, 66%, is questioned. Reason being active treatment was found to control stroke better (p=-0.07) in men as compared to reducing total mortality in women (p=0.06). on the other hand, this article has a strong base to prove its credibility bin that it has put into consideration effects of various factors for instance smoking/alcoholism, age, geographical origin, sex, and other complications for instance diabetes mellitus. Notes In my opinion this case study on elderly Chinese suffering from Isolated Systolic hypertension is a future reference point in advocating for active antihypertensive treatment. This is in particular fro hypertensive patients who are stared with dihydropyridine calcium channel blocker. Author/ journal Rashid et al. (2003) Purpose/significance The main objective of this meta-analyses and systematic review was to establish the effects of reducing blood pressure in controlling recurrent cardiovascular complications among patients with historical stroke related complications. The research was based on the notion 5that high blood pressure is an imminent risk factor in causing stroke. In this article, it is alleged that an increase in diastolic blood pressure by 10 mm Hg results in more than half increases of risk in stroke. Methods Meta-regression analysis and systematic review of the seven Randomized Trials alongside eight comparison groups was done. The RCTs were sourced from MEDLINE and EMBASE electronic databases. The authors also considered inclusion of non-confounded RCT in determining the effect of reducing blood pressure in patients with historical stroke complications. Variables included the stroke subtype, time-period form stroke to enrollment, history of past hypertension, type of antihypertensive treatment, baseline blood pressure, follow-up period, variation in blood pressure between control groups and treatments. In the analysis, data was fed into RevMan Version 4.1 for crosschecking. 95 % CIs and Odd Ratios (Ors) were calculated using random effect models. Resultant heterogeneity was evaluated using X2 test. Meta-regression analysis was done using ‘Metarag’ function in strata statistical package whereas publication bias was evaluated using Eggre’s test and Begg’s funnel plot. Results It is only seven RCTs that met the required criteria among those published. The sample size for all the trials totaled to 15527 and patients enrolled into these trials had ischemic stroke, TIA, and primary intra-cerebral hemorrhage. In regard, to blood pressure, active treatment caused small end-of-trial reductions of diastolic and systolic ( Read More