Page 833 - Cardiac Nursing

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C HAPTER 35 / Hypertension 809
other lifestyle modifications specifically limiting alcohol intake to Drug treatment included felodipine, a calcium channel antago-
1 oz or less per day and increasing physical activity to a minimum nist, followed by the use of an ACE inhibitor or -blocker and if
of 180 minutes (3 hours) each week. 79,126,131 While the DASH needed a diuretic. In the last 6 months of the trial, the mean BPs
diet is effective, adopting these dietary recommendations presents in the three respective groups were 81, 83, and 85 mm Hg. When
a great challenge for many individuals. Description of the DASH the relationship between BP and study outcomes was examined,
diet and sample menus is available on the National Heart, Lung, the lowest risk for CVD events was a pressure of 138.5/82.6 mm
and Blood Institute Web site. Hg, for stroke 142.2/80 mm Hg, and for cardiovascular mortality
138.8/86.5 mm Hg. The greatest benefit from lowering of DBP
Reduction of Alcohol Intake. Observational studies and
was noted in diabetics where a pressure of 90 mm Hg was asso-
clinical trials have documented a direct, dose-dependent relation-
ciated with 24.4 events, a pressure of 85 mm Hg with 18.6
ship between alcohol intake and BP, particularly as the intake of al-
cohol increases above two drinks per day. 79,132–135 Meta-analysis of events, and a pressure of 80 mm Hg associated with 11.9 events,
(
all were statistically significant (p .005). This trials provided
15 randomized controlled trials demonstrated that decreased con-
strong evidence to support lower BP targets among hypertensive
sumption of alcohol (median reduction in self-reported alcohol
patients with diabetes. Follow-up studies have shown the very
consumption, 76%; range, 16% to 100%) reduced SBP and DBP
by 3.3 and 2.0 mm Hg, respectively. 136 BP reductions were simi- positive effects of lowering SBP and DBP in patients with renal
disease, diabetes, and heart failure. The only cautionary note
lar in nonhypertensive and hypertensive individuals. Importantly,
about lowering DBP lies with the population of older adults. The
the relationship between reduction in mean percentage of alcohol
Rotterdam Study of 2,351 subjects showed that the risk of stroke
and decline in BP was dose dependent. However, there may be
increased significantly when DBP was reduced to 65 mm
benefit to moderate levels of alcohol consumption. A case-control 152
Hg. A follow-up analysis of the Systolic Hypertension in the
study of adults older than 40 years found a lower incidence of is-
Elderly Program (SHEP) data also showed that people who suf-
chemic stroke in persons with an alcohol intake of one to two
drinks per day compared with abstainers. 137 fered a CVD event had lower DBPs (65 mm Hg) than those who
153
had no event (68 mm Hg). However, the International Verapamil
JNC 7 recommends that alcohol consumption should be lim-
SR/Trandolapril (INVEST) study showed benefit when BP was low-
ited to 2 alcoholic drinks per day in most men and 1 alcoholic
drink per day in women and lighter-weight persons. 7,79 A stan- ered to 64 mm Hg in the older adults which included a reduction in
154
CVD events. Thus the question of the “J” curve (lowering BP too
dard drink has been defined as approximately 14 g of alcohol,
low to perfuse organs may increase CVD events) appears to remain
which is the amount contain in 12 oz of beer, 5 oz of wine, or 1.5
but perhaps only in the older adults population and the research to
oz of distilled liquor such as vodka, gin, or scotch. 155
date has been performed only in a small number of patients.
Control of Other Risk Factors. Any individual who has an The second question relates to the relative risks and benefits of
elevated SBP or DBP has an increased risk for atherosclerotic different classes of antihypertensive medicines. Some experts be-
CVD. In addition, longitudinal epidemiologic studies have shown lieve that medicines like thiazide diuretics and -blockers are as
that the major risk factors have an additive effect on the probabil- effective in lowering BP and reducing risk as newer agents such as
ity that an individual will have a morbid or mortal event. 138–141 ACEs, ARBs, and calcium channel blockers. 156 This led to the
Therefore, even though smoking cessation and improving dyslipi- Antihypertensive and Lipid Lowering Treatment to Prevent Heart
demia will not decrease BP, these interventions will reduce the risk Attack Trial (ALLHAT), which followed 42,418 subjects, aged
of morbidity and mortality from atherosclerotic CVD. 142–148 55 years and older from 18 countries (623 sites in North America)
who were randomly allocated to receive chlorthalidone, amlodip-
Pharmacologic Management ine, doxazosin, or lisinopril for an average of 4.9 years. 157 Addi-
Since the 1960s, randomized, placebo-controlled, clinical trials tional agents including atenolol, clonidine, or reserpine and if
have provided evidence that pharmacologic treatment of HTN re- necessary hydralazine could be added as necessary to maximum
duces morbidity and mortality. The Veterans Administration Co- doses of the drugs originally assigned. The doxazosin arm was
operative Group Studies on Antihypertensive Agents were the first stopped early due to a significant increase in combined cardio-
studies in the United States demonstrating that drug treatment vascular endpoints. At the end of the study period, there were no
was extremely beneficial in people with moderate and severe differences between the three treatment groups for the primary
HTN. 149,150 Subsequent clinical trials have explored the benefits outcome, which was a combination of fatal coronary heart dis-
of treatment in more representative populations as well as at lower ease or nonfatal myocardial infarction or for all-cause mortal-
BP levels. In addition, more recently, the value of lowering SBP to ity. 157 The study also showed the value of the thiazide diuretic on
reduce risk has had a major impact on how we initiate pharma- secondary endpoints. More strokes occurred in those patients
cotherapy and titrate and use additional therapies to control BP. assigned to lisinopril compared with those assigned to
The use of drugs in special populations also confers numerous chlorthalidone (6.3% vs. 5.6%, p .02). Heart failure was also
treatment choices designed to treat HTN and reduce CVD risk more common in those patients receiving newer agents (chlorthali-
and other TOD. done, 7.7%, amlodipine, 10.2%, lisinopril, 8.7%, p .0001).
Two questions continue to remain paramount in the treatment Continued discussion, which relates to many follow-up studies
of HTN. The first is how low should BP be lowered, and the sec- today is around whether it is truly the specific agent or the reduc-
ond relates to the relative risks and benefits of the different classes tion in BP that contributes to better outcomes. Just 2 months fol-
of antihypertensive medications. The Hypertension Optimal lowing the release of ALLHAT the results of the Second Aus-
Treatment (HOT) trial of 18,790 men and women, aged 50 to 80 tralian National Blood Pressure Study (ANBP2) were published
years from 20 countries helped to respond to the issue of how low with contradictory results. 158 ANBP2 compared the efficacy of
should BP be lowered. 151 Within this trial, subjects were ran- the diuretic hydrochlorothiazide with an ACE inhibitor,
domly allocated to three target DBPs, 80, 85, and 90 mm Hg. enalapril, in 6,083 subjects (50% women) aged 65 to 84 years