Left atrial size in hypertensive men: influence of obesity, race and age. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

OBJECTIVES

We sought to determine the relations of left atrial (LA) size to blood pressure, obesity, race, age and left ventricular (LV) mass in hypertension.

BACKGROUND

Although obesity, race and age may influence LV mass, their effects on LA size have not been defined in hypertension.

METHODS

Left atrial size was measured in 690 men (58% African-Americans) with mild to moderate hypertension (mean [+/-SD] blood pressure 152 +/- 15/98 +/- 6 mm Hg) and a high prevalence of LV hypertrophy. Effects of LV mass, adiposity, race, age, physical activity, height, weight, sodium excretion, plasma renin activity and heart rate were examined.

RESULTS

Left atrial size was greater (p < or = 0.0001) in obese (44.2 +/- 5.7 mm) than in overweight (41.6 +/- 5.9 mm) or normal weight (38.9 +/- 6.2 mm) patients. Left atrial enlargement (> or = 43 mm) was present in 56% of obese patients compared with 42% of overweight and 25% of normal weight hypertensive men. As age increased, white patients had a greater LA size than African-American patients. Although there was no relation between LV mass and LA size in normal weight patients, there was a significant positive relation in obese patients. On multiple regression analysis, obesity was the strongest independent predictor of increased LA size.

CONCLUSIONS

Obesity is the strongest predictor of LA size in patients with hypertension and amplifies the relation between LA size and LV mass. Race influences effects of age and hypertension on LA size. Because increased LA size and LV mass (also influenced by obesity) are associated with an adverse outcome, these findings underscore the importance of obesity, race and age with regard to the cardiac effects of hypertension.

Prevention of diabetic nephropathy

Normalization of blood pressure--and use of an ACE inhibitor or AT1-receptor blocker for patients with abnormal albumin or creatinine levels--can prevent or significantly slow the rate of progression toward end-stage renal disease.

Lessons from combination therapy in Veterans Affairs Studies. Department of Veterans Affairs Cooperative Study Group on antihypertensive agents

A subset of 102 patients of an original cohort of 1292 with stage 1 to 2 hypertension was characterized by having failed to achieve goal blood pressure (< 90 mm Hg diastolic) after treatment with two single antihypertensive drugs. These patients were given a combination of the two drugs on which they had failed to achieve blood pressure goal when they were administered as single-drug therapy. The drugs were hydrochlorothiazide, atenolol, captopril, diltiazem-SR, clonidine, and prazosin. We examined the responses in each of the drug combination categories by the order that the drugs were administered, by estimated total response rates for the combinations, and by age and race. The order of drug administration did have an effect for some of the drug pairs. This was of two types: 1) different results for each member of the pair, but the same combination result; and 2) different end result of the combination. An example of the first type is that prazosin had only a 6% response rate in patients who had failed on diltiazem, while diltiazem had a 22% response rate in patients who had failed on prazosin. Nevertheless, the combinations yielded the same total responses (86% and 84%) regardless of order. An example of the second type is that captopril-diltiazem was less effective in total response than diltiazem-captopril (88% v 97%). Differences were seen in the response to combinations in the race and age groups. There were ordering differences of type similar to those described above. We conclude that combination drug therapy is highly effective even when the individual components have failed and that some differences in response by order of drug administration may occur.

Comparison of plasma lipid and lipoprotein profiles in hypertensive black versus white men. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

An abnormal plasma lipid and lipoprotein profile is an independent and strong predictor of mortality and morbidity from coronary artery disease (CAD). We report on plasma lipid and lipoprotein profiles with respect to race, age, obesity, blood pressure (BP), smoking, and drinking history in 1,292 male veterans with a diastolic BP of 95 to 109 mm Hg while off antihypertensive medications. Blacks had 24% (p <0.001) lower triglycerides than whites. In contrast, the following parameters were higher in blacks than in whites by the indicated percentages: high-density lipoprotein (HDL) cholesterol, 16% (p <0.001); HDL2 cholesterol, 36% (p <0.001); apolipoprotein (Apo) A1, 8% (p <0.001); HDL/low-density lipoprotein (LDL), 18% (p = 0.018); HDL2/LDL, 36% (p = 0.031); HDL2/HDL3, 21% (p <0.001); and Apo A1/Apo B, 15% (p <0.001). Triglycerides were unchanged up to age 60, but were lower by 24% (p <0.001) in those aged > or = 70. Apo A1 levels were higher (p <0.001), whereas LDL cholesterol was lower (p <0.008) in moderate alcohol consumers versus abstainers. Triglycerides were higher (p <0.001), whereas HDL, HDL2 cholesterol, and Apo A1 were lower (p <0.001) with increasing obesity. Moderate alcohol consumption had a strong favorable effect on HDL, HDL2, and HDL3 cholesterol among subjects of normal weight, but this effect was diminished in obese subjects. Total and LDL cholesterol were higher by 6.4% (p = 0.001) and 9.4% (p <0.003), respectively, whereas HDL cholesterol remained unchanged in those with diastolic BP of 105 to 109 mm Hg versus those with diastolic BP of 95 to 99 mm Hg. We conclude that hypertensive black men have lipid and lipoprotein profiles indicative of less CAD risk than white men. Chronic moderate alcohol consumption correlates with a favorable plasma lipid and lipoprotein profile in normal, but not obese, men. Obesity is associated with an adverse plasma lipid and lipoprotein profile. Thus, race, alcohol intake, and obesity may be important modifiers of CAD in untreated hypertensive men.

Hypertension in Haitians: results of a pilot survey of a public teaching hospital multispecialty clinic

Little is known about hypertension in Haitians. We performed a pilot survey of ambulatory Haitian patients in a multispecialty clinic at a large public teaching hospital. Approximately 10% of the clinic population was of Haitian origin. Clinical data were collected on 88 consecutive Haitian patients. Of these 88, 77 (87.5%) were hypertensive (SBP > or = 140 or DBP > or = 90 mm Hg or taking antihypertensive medication). The characteristics of the hypertensive patients were: age 54.1 +/- 13.0 (s.d.) years; 27 men, 50 women; 12/64 (19%) smoked; 7/63 (11%) used alcohol. Diabetes was present in 21/77 (27%). In patients for whom height and weight were available, obesity was present in 52%. Using JNC V criteria, 18 (23%) had Stage 1, 16 (21%) Stage 2, 18 (23%) Stage 3, and 25 (33%) Stage 4 hypertension. Despite 63/77 (82%) being treated for hypertension, only 20 (26%) were controlled (< 140/< 90 mm Hg). Of those under treatment, 29 were taking one drug; 18 (two drugs); 12 (three drugs); and four (four drugs). Target organ damage was evident in 37 (48%), including coronary artery disease (8), CHF (6), chronic renal failure (15), stroke (9), and LVH by ECG (19). There was evidence of severe noncompliance in 32 (42%). We conclude that in this clinic sample, hypertension was highly prevalent and unusually severe in terms of blood pressure (BP) level, refractoriness to treatment, and target organ consequences. Further studies are indicated.

Lessons on the interaction of race and antihypertensive drugs from the VA cooperative study group on antihypertensive agents

The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents, organized by Dr. Edward D. Freis, has made numerous contributions to our knowledge about hypertension and its treatment. In the late 1970s the group observed post hoc that there were racial differences in response to hydrochlorothiazide and propranolol. Subsequent studies were designed to seek out racial differences if they existed. A series of observations led to the design of a comparative study of six drugs and placebo used as single-drug therapy of mild to moderate hypertension in men. Further analyses of those data have indicated that racial differences still exist when a second drug is substituted for a failed first drug. A combination of two drugs that had previously failed to achieve control of blood pressure did produce control in 58% of the patients. Electrocardiographic data suggested that black patients were much more likely to have left ventricular hypertropy (LVH) than whites, but analysis of echocardiograms showed that there was no racial difference in the prevalence of LVH. Additional analyses are in progress addressed to serum lipid changes, proteinuria, and drug-induced changes in left ventricular mass.

Results of combination anti-hypertensive therapy after failure of each of the components. Department of Veterans Affairs Cooperative Study Group on Anti-hypertensive Agents

We randomised ambulatory men with diastolic blood pressure (BP) 95-109 mmHg without anti-hypertensive medication to single drug treatment with either hydrochlorothiazide 12.5-50 mg/day, atenolol 25-100 mg/day, captopril 25-100 mg/day, clonidine 0.2-0.6 mg/day, diltiazem-SR 120-360 mg/day, prazosin 4-20 mg/day or placebo in a double-blind prospective trial. The assigned drug was titrated to a goal BP of < 90 mm Hg. Patients not achieving goal BP were rerandomised to an alternative single active drug. Non-responders to the second drug received the first drug in combination with the second. Of the 102 non-responders to both drugs who qualified for the combination, 59 (57.8%) responded. The combination pairs that included a diuretic achieved diastolic goal BP in 69% and < 140 mm Hg systolic in 77% compared with 51% and 46%, respectively, for those combinations without a diuretic (P = 0.067; P = 0.002). Six of the eight terminations due to adverse drug reactions were in combinations containing prazosin; three of these six were hypotensive reactions. We conclude that two single drugs of insufficient efficacy to control BP individually have a high probability of achieving goal BP when combined, especially if the combination contains a diuretic.

Response to a second single antihypertensive agent used as monotherapy for hypertension after failure of the initial drug. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

BACKGROUND

An important issue in clinical practice is how to treat patients whose blood pressure does not respond to the first antihypertensive drug selected.

OBJECTIVE

To analyze the antihypertensive response of patients who had failed to achieve their diastolic blood pressure goal (< 90 mm Hg at the end of 8 to 12 weeks of titration) with one of six randomly allocated drugs or placebo to the random allocation of an alternate drug.

METHODS

We initially randomized 1292 men with diastolic blood pressure of 95 to 109 mm Hg to treatment with hydrochlorothiazide, atenolol, captopril, clonidine hydrochloride, diltiazem hydrochloride (sustained release), prazosin hydrochloride, or placebo. Of 410 men in whom initial treatment failed, 352 qualified for randomization to the alternate drug.

RESULTS

Of the 352 patients, 173 (49.1%) achieved their goal diastolic blood pressure, in 133 (37.8%) the alternate drug failed, and 46 (13.1%) left the study for various reasons. Overall response rates were as follows: diltiazem, 63%; clonidine, 59%; prazosin, 47%; hydrochlorothiazide, 46%; atenolol, 41%; and captopril, 37%. The best response rate for patients in whom hydrochlorothiazide failed was achieved with diltiazem (70%); after atenolol failure, clonidine (86%); after captopril failure, prazosin (54%); after clonidine failure, diltiazem (100%); after diltiazem failure, captopril (67%); and after prazosin failure, clonidine (53%). The combined response rate for patients initially randomized to an active treatment was 76.0%, which is similar to that achieved by the combination of two drugs in previous studies.

CONCLUSIONS

We conclude that sequential single-drug therapy is a rational approach for treatment of hypertension in patients in whom initial drug therapy has failed.

Calcium channel blockers. Is it time to split the lump?

Antihypertensive drug classes such as thiazide diuretics, angiotensin-converting enzyme inhibitors, beta-adrenergic blocking agents, peripheral alpha 1-antagonists, and central alpha 2-agonists all describe therapeutic agents that are quite similar to each other and strikingly different from members of the other classes. A glaring exception is the rubric "calcium channel blocker," under which strikingly dissimilar drugs have been lumped. Although the phenylalkylamines (verapamil and gallapamil) and benzothiazepines (diltiazem and TA3090) bind at different receptors on the alpha 1 component of the calcium channel, they are reasonably similar in their clinical pharmacology. For example, both types of drugs slow the heart rate and there are intravenous preparations that are used to treat supraventricular tachycardia. The dihydropyridines (nifedipine and many others) bind to another receptor on the alpha 1 component, but have markedly different pharmacologic properties. For example, they tend to increase the heart rate, do not cause constipation, but are more likely to cause peripheral edema. I propose that we refer to this entire class of drugs as "calcium antagonists," that we continue to refer to verapamil, diltiazem, and similar drugs as "calcium channel blockers," but recognize the very different properties of nifedipine and like drugs by referring to them as dihydropyridines or DHPs.

Department of veterans Affairs single-drug therapy of hypertension study. Revised figures and new data. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

The antihypertensive efficacy of six drugs and placebo was compared in 1292 men with untreated diastolic blood pressure of 95 to 109 mm Hg. The primary end point "success" was defined as the patient having achieved a diastolic blood pressure of < 90 mm Hg at the end of the drug titration period and having maintained a diastolic blood pressure of < 95 mm Hg for 1 year without drug intolerance. The original published success rate data (N Engl J Med 1993;328:914-921) were discovered to be in error due to a computer programming code omission (N Engl J Med 1994;330:1689). This paper presents corrected graphic figures. The corrected success rates were generally higher than originally published. Overall, diltiazem (72%) was significantly higher than hydrochlorothiazide (55%), prazosin (54%), captopril (50%), and placebo (31%); clonidine (62%) and atenolol (60%) were intermediate. There were some changes in the hierarchy of drug response, but important differences in success rates according to age by race subgroups remained. Whites responded well to all drug classes, except for lower efficacy of hydrochlorothiazide in younger whites. Blacks responded better to diltiazem than other agents. In addition, we have analyzed the data using a definition of success based on < 90 mm Hg for 1 year. Use of the <90 mm Hg criterion reduced the rate of success, but had only a minor effect on the drug success rate hierarchy. We conclude that single-drug antihypertensive therapy is effective in a majority of stage 1 to 2 diastolic hypertensive patients, although there are important age-by-race differences in success rates among various drug classes.

Importance of obesity, race and age to the cardiac structural and functional effects of hypertension. The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

OBJECTIVES

The purpose of this study was to determine the effects of obesity and its interaction with age, race and the magnitude of blood pressure elevation in a large cohort of patients with mild to moderate hypertension and a high prevalence of left ventricular hypertrophy.

BACKGROUND

Obesity, race and age each have important effects on the incidence and severity of hypertension and may contribute to the effects of blood pressure elevation on the cardiac manifestations of hypertension.

METHODS

Left ventricular structure and function were assessed with two-dimensional targeted M-mode echocardiography in 692 men with mild to moderate hypertension (average blood pressure 153/100 mm Hg), and the data were compared in relation to obesity (determined from body mass index), age, race, blood pressure, physical activity, plasma renin activity, urinary sodium excretion, hematocrit, heart rate and serum lipids.

RESULTS

Left ventricular hypertrophy was common (63% with increased left ventricular mass, 22% with left ventricular hypertrophy on the electrocardiogram [ECG]). On multivariable regression analysis, body mass index was the strongest predictor of left ventricular mass and magnified the slope relation of blood pressure to left ventricular mass. Despite a greater prevalence of ECG left ventricular hypertrophy in blacks (31%) than in whites (10%), left ventricular mass and echocardiographic prevalence of left ventricular hypertrophy did not differ by race. However, septal, posterior left ventricular and relative wall thickness were greater in black than in white men.

CONCLUSIONS

Obesity is the strongest clinical predictor of left ventricular mass and left ventricular hypertrophy in men, even in those with mild to moderate hypertension of sufficient severity to be associated with a high prevalence of left ventricular hypertrophy. Moreover, independent effects of systolic blood pressure on left ventricular mass are amplified by obesity. Although race does not affect left ventricular mass or the prevalence of left ventricular hypertrophy, black race is associated with greater relative wall thickness, itself a predictor of unfavorable cardiovascular outcome.

Modern strategies to prevent coronary sequelae and stroke in hypertensive patients differ from the JNC V Consensus Guidelines

In recent years, government agencies of many countries have established consensus guidelines for the evaluation and treatment of hypertension. Once published, guidelines tend to be perceived as directives by a variety of health care providers. Unfortunately, these guidelines often do not reflect the practices of most hypertension experts. This report summarizes the opinions of seven hypertension experts concerning the impact of "official" guidelines on clinical practice. In addition, the individual therapeutic recommendations of these panel members are summarized. Their different treatment strategies reflect the diversity of first rate treatment plans that aim to reduce the cardiovascular sequelae in individual patients with essential hypertension. Most importantly, not one of these seven treatment strategies followed the "preferred" treatment of the U.S. guidelines, which recommend diuretics and beta-blockers as first-line therapy. The present authors approach the treatment of hypertension as a means to reduce cardiovascular events. Thus, reduction of blood pressure is not the most important therapeutic endpoint. The panel believes that whereas many different drugs can produce effective blood pressure reduction, the modern primary goal of antihypertensive drug therapy is to select a regimen most likely to prolong the quality and duration of life. In real terms, this means that the primary goal of treatment is the prevention of the major vascular sequelae of hypertension (heart attack, ventricular remodeling, hypertrophy, heart failure, and stroke) that shorten useful life. There are a number of effective hypertensive treatments, which can be selected based on individual patient requirements. However, many consensus guidelines do not allow the flexibility required to optimize individual patient treatment. As a result, health care providers should not feel compelled to regard the preferences of "official" guidelines as the best, modern, state-of-the-art therapy for an individual patient. All seven experts who are deeply involved in the daily care of patients preferred drugs other than beta-blockers and diuretics (the Joint National Committee [JNC] choices) for first-line therapy of hypertension.

Angiotensin-converting enzyme inhibitors in hypertension. A dozen years of experience

Introduction of the first angiotensin-converting enzyme (ACE) inhibitor, captopril, in 1981 marked a major advance in the treatment of essential hypertension. This article reviews the 12 years of clinical experience during which it and other ACE inhibitors have become recognized as first-line agents for treating hypertension. The benefits of ACE inhibition in diabetic patients are being defined. In recent years, beneficial effects on glucose handling, left-ventricular mass, quality of life, renal function, and myocardial protection have become recognized. For these reasons, and because of their excellent safety profile, ACE inhibitors are now widely used for the treatment of hypertensive patients.

Alterations in heart rate variability and its circadian rhythm in hypertensive patients with left ventricular hypertrophy free of coronary artery disease

Heart rate variability (HRV) and its circadian rhythm were evaluated in 22 patients with treated hypertension and left ventricular hypertrophy in whom coronary artery disease was excluded by stress thallium or angiography. By using 24-hour Holter monitoring, HRV and its spectral components were measured. Findings were compared with 11 age-matched normal controls. The difference between mean R-R intervals during sleep (11 PM to 7 AM) and while awake (9 AM to 9 PM) (73 +/- 33 vs 263 +/- 63 msec, p < 0.0001) and the mean 24-hour SD of the R-R intervals (55 +/- 6.3 vs 93 +/- 11, p < 0.0001) were lower among the hypertensive patients compared with controls. The percentage of difference between successive R-R intervals that exceeded 50 msec, a measure of parasympathetic tone, was also lower among the hypertensive patients (6.8 +/- 7.1 vs 13.6 +/- 8.9, p < 0.002); it increased at night and decreased during the day among the controls, and this circadian rhythm was blunted among the patients. Spectral analysis showed that power in the high-frequency range (0.15 to 0.40 Hz) was lower among the hypertensive patients during 21 of 24 hours but that the difference was statistically significant only during 9 hours (p ranging from < 0.05 to 0.009). Power in the low-frequency range (0.04 to 015 Hz) was lower at night, increased in the morning, and higher during the day among controls; this circadian rhythm was absent among hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

[The cost of quality assurance]

This paper views quality assurance costs as appraisal costs. We used cost accounting techniques to estimate the cost of quality assurance activities in a large university affiliated Veteran Administration Medical Center. In addition to the personnel employed full-time for quality assurance activities, all other employees in or directly in support of clinical services were interviewed in order to determine the per cent of their work time devoted to specific quality assurance activities. The per cent time committed was multiplied by the salary and benefits package for each employee and the total computed for the facility. In addition, non-salary overhead expenses were estimated by multiplying the salary and fringe benefit costs to the ratio of total medical center non-personnel costs to total medical center costs. We found that 3.39 per cent of the total budget or $4,884,775 was devoted to quality assurance activities. The highest costs aside from the designated quality assurance personnel were for pharmacy, Laboratory, extended care (including nursing home), psychiatry, and nursing services. We did not attempt a formal benefit analysis. We concluded that quality assurance activities in a major medical center are not free. Careful cost accounting studies should be performed both to determine the cost of quality assurance and to identify its specific benefits.

Single-drug therapy for hypertension in men. A comparison of six antihypertensive agents with placebo. The Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents

BACKGROUND

Characteristics such as age and race are often cited as determinants of the response of blood pressure to specific antihypertensive agents, but this clinically important issue has not been examined in sufficiently large trials, involving all standard treatments, to determine the effect of such factors.

METHODS

In a randomized, double-blind study at 15 clinics, we assigned 1292 men with diastolic blood pressures of 95 to 109 mm Hg, after a placebo washout period, to receive placebo or one of six drugs: hydrochlorothiazide (12.5 to 50 mg per day), atenolol (25 to 100 mg per day), captopril (25 to 100 mg per day), clonidine (0.2 to 0.6 mg per day), a sustained-release preparation of diltiazem (120 to 360 mg per day), or prazosin (4 to 20 mg per day). The drug doses were titrated to a goal of less than 90 mm Hg for maximal diastolic pressure, and the patients continued to receive therapy for at least one year.

RESULTS

The mean (+/- SD) age of the randomized patients was 59 +/- 10 years, and 48 percent were black. The average blood pressure at base line was 152 +/- 14/99 +/- 3 mm Hg. Diltiazem therapy had the highest rate of success: 59 percent of the treated patients had reached the blood-pressure goal at the end of the titration phase and had a diastolic blood pressure of less than 95 mm Hg at one year. Atenolol was successful by this definition in 51 percent of the patients, clonidine in 50 percent, hydrochlorothiazide in 46 percent, captopril in 42 percent, and prazosin in 42 percent; all these agents were superior to placebo (success rate, 25 percent). Diltiazem ranked first for younger blacks (< 60 years) and older blacks (> or = 60 years), among whom the success rate was 64 percent, captopril for younger whites (success rate, 55 percent), and atenolol for older whites (68 percent). Drug intolerance was more frequent with clonidine (14 percent) and prazosin (12 percent) than with the other drugs.

CONCLUSIONS

Among men, race and age have an important effect on the response to single-drug therapy for hypertension. In addition to cost and quality of life, these factors should be considered in the initial choice of a drug.

Antihypertensive drug therapy does not perturb the circadian blood pressure pattern

The literature was reviewed to determine whether failure of older antihypertensive drugs to suppress the early morning increase of blood pressure was responsible, in part, for the less than satisfactory rate of reduction in cardiovascular mortality rates in the United States. The authors found that neither the old nor the new antihypertensive drugs altered the 24-hour blood pressure curve pattern, although long-acting drugs did show continued effect at the end of the 24-hour period when compared with placebo. The efficacy of these drugs most likely lies with their blood pressure lowering and other ancillary effects and not with pattern changes. More importantly, examination of new data (1989) shows that the rate of decline in death due to diseases of the heart has exceeded that for cerebrovascular diseases. Our overall health care effort may be more successful than we thought.

Adverse effects of angiotensin-converting enzyme inhibitors in antihypertensive therapy with focus on quinapril

Angiotensin-converting enzyme (ACE) inhibitors are useful first-line drugs in the therapy of mild and moderate hypertension. Adverse reactions to this drug class are rarely serious. Hypotension, cough, rash, and taste disturbance are uncommon; reduced glomerular filtration and hyperkalemia occur infrequently; angioedema is rare and neutropenia is extremely rare. Quinapril is a new ACE inhibitor that is converted to biologically active quinaprilat in the liver. This ACE inhibitor has a rapid onset of action and inhibits local tissue converting enzyme systems in kidney, heart, and brain, as well as in the circulating renin-angiotensin system. Clinically significant adverse effects of quinapril occur at low rates. In 1,771 patients receiving quinapril, the reported incidence of the first occurrence of orthostatic hypotension was comparable to that seen in patients receiving placebo. In other studies, headache was reported by up to 4.7% of patients receiving quinapril, which is comparable to reported incidences of headache in patients receiving other ACE inhibitors. Other adverse events reported at rates greater than 1% include cough with associated rhinitis and bronchitis, dizziness, and somnolence. Such adverse events have only rarely led to the withdrawal of patients from clinical studies of quinapril.