Angiotensin II receptor antagonists: a new approach to blockade of the renin-angiotensin system

A-II exerts its activity on various target tissues by binding to its receptors. The discovery of local RASs and A-II receptors within various tissues has generated interest in the clinical usefulness of RAS inhibition by directly blocking the action of A-II at the receptor level. Different A-II receptor subtypes have been identified and subsequently termed AT1 and AT2. AT1-receptor subtypes are the predominant receptor subtypes existing in most organs and, by coupling to a transmembrane G protein, seem to be the main subtypes participating in the vasoactive responses of A-II. Saralasin, a peptide with specific A-II receptor-antagonistic activity, had limited practical long-term usefulness as a result of its short half-life, significant agonistic properties, and lack of oral bioavailability. The discovery of simple benzyl-substituted imidazoles, which possess weak but highly selective A-II receptor antagonistic properties, led to the development of losartan (DuP 753). Losartan is a potent, orally active, specific, competitive nonpeptide A-II receptor antagonist that appears to be an effective antihypertensive agent both in animal studies and in preliminary clinical trials. The therapeutic usefulness of losartan, however, is not limited to its antihypertensive effects. The potential benefits of A-II receptor antagonists include roles in postmyocardial infarction therapy, slowing A-II-induced cardiac hypertrophy, 154, 155 slowing the progression of heart failure, preventing postangioplasty restenosis, and in slowing the progression of renal disease. Furthermore, losartan, a selective A-II type 1 (AT1) receptor antagonist, has also been a valuable pharmacologic probe for studying the mechanism of A-II stimulation of its receptors. A-II receptor antagonism appears to be as effective as ACE inhibition in the treatment of hypertension and other pathologic processes that involve the RAS and may offer an alternative to those patients who cannot tolerate ACE inhibitors because of their side effects.

Ischemic hepatitis in a patient with congestive cardiomyopathy: an innovative approach to therapy using intravenous dobutamine

Patients who sustain a transient period of hypotension or low cardiac output can develop massive elevations of the serum transaminases without serum markers of acute hepatitis, a recent myocardial infarction or exposure to toxins and chemicals. This condition is often termed "ischemic hepatitis" (IH), with its pathological correlate being centrilobular necrosis. Recognition of IH can help in the appropriate management of these patients, and avoid unnecessary diagnostic testing. The authors describe a patient with congestive cardiomyopathy in whom IH developed as part of a complicated hospital course. The condition appeared to reverse with the administration of dobutamine, suggesting inotropic therapy as an appropriate treatment modality.

Mononitrates: defining the ideal long-acting nitrate

As a result of recent advances in our understanding of the role of nitric oxide and endothelial-derived relaxing factor (EDRF) in vascular control, physicians now have the potential to overcome the loss of EDRF effect by administering nitrates. Nitrates are converted to nitric oxide, resulting in vasodilator effects that improve the myocardial oxygen supply-demand imbalance responsible for myocardial ischemia. This discovery has resulted in a renewed interest in the nitrates for the treatment of ischemic syndromes, particularly chronic stable angina pectoris. Over the past 2 years, an important new formulation of nitrate has become available--isosorbide-5-mononitrate. Three different mononitrate formulations are available in the United States: Ismo tablets in December 1992; followed over a year later by Monoket tablets, available since June 1993; and Imdur extended-release tablets, available since August 1993. Although the mononitrates share the same generic name, they are not similar in regard to their formulations, which suggests the need for future studies designed to explore any clinical differences.

Cost-effectiveness of antihypertensive agents in patients with reduced left ventricular function

A pharmacoeconomic primer reviews current economic models used to analyze and synthesize information that may be considered in certain health-related policies or clinical decisions. Heightened budgetary pressures concomitant with mandates for demonstrable increases in efficacy and safety have fostered greater use of cost-effectiveness analyses (CEAs) throughout the health care industry. In the field of hypertension, major clinical trials of pharmacotherapeutic regimens generally demonstrated benefit of reducing blood pressure; CEAs supplied additional data concerning the optimum selection among alternative antihypertensive therapies. As interest has focused on the preservation of left ventricular (LV) function for the best prognosis, it has become increasingly evident that not all antihypertensive regimens affect LV function in the same way. Thus CEA may be an appropriate method to evaluate these effects and facilitate the identification of a regimen that minimizes deterioration of LV function.

Amlodipine versus atenolol in essential hypertension

The efficacy and safety of amlodipine (2.5-10 mg) once daily was compared with atenolol (50-100 mg) once daily in patients with mild-to-moderate essential hypertension in a randomized, double-blind, parallel, placebo-controlled study. A total of 125 patients were randomly allocated at the end of a 4-week run-in placebo period to 8 weeks of double-blind treatment with amlodipine (n = 41), atenolol (n = 43), or placebo (n = 41). The placebo group had small mean changes in supine and standing blood pressure compared with baseline. The mean blood pressure changes from baseline 24 hours postdose in the amlodipine group (mean daily dose 8.8 mg) were -12.8/-10.1 mm Hg for supine blood pressure and -11.5/-9.8 mm Hg for standing blood pressure (p < 0.001 compared with placebo), and for the atenolol group (mean daily dose 83.7 mg) the changes were -11.3/-11.7 mm Hg for supine blood pressure and -13.3/-12.3 mm Hg for standing blood pressure (p < 0.001 compared with placebo). There were no statistically significant blood pressure differences between active treatments. The responder rates for amlodipine, atenolol, and placebo were 61.1, 64.9, and 11.1%, respectively. The blood pressure values taken over the 24-hour period at final visit revealed that amlodipine and atenolol maintained the supine blood pressure < or = 140/90 mm Hg throughout the period of observation; the corresponding time-effect curve for the placebo group was clearly in the hypertensive range. Both amlodipine and atenolol were well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II receptor blockade: an innovative approach to cardiovascular pharmacotherapy

Through the multiple actions of angiotensin II (AII), the renin-angiotensin system (RAS) participates in cardiovascular homeostasis. Angiotensin II acts by binding to specific membrane-bound receptors, which are coupled to one of several signal transduction pathways. These AII receptors exhibit heterogeneity, represented by AT1 and AT2 receptor subtypes. The AT1 receptor mediates the major cardiovascular action of the RAS. This receptor has been cloned from multiple species, disclosing features consistent with a transmembrane, G-protein-linked receptor. Further AII receptor heterogeneity is evident by the cloning of isotypes of the AT1 receptor. Blocking the interaction of AII with its receptor is the most direct site to inhibit the actions of the RAS. Many AII receptor antagonists, including peptide analogs of AII and antibodies directed against AII, possess unfavorable properties that have limited their clinical utility. The discovery and further development of imidazole compounds with AII antagonist properties and favorable characteristics, however, has promise for clinical utility. The leader in this field is a selective AT1 receptor antagonist losartan (previously known as DuP 753 or MK-954). Losartan was demonstrated to be an effective antagonist of many AII-induced actions and an effective antihypertensive agent in many animal models of hypertension (HTN). Losartan also demonstrated secondary benefits in preventing stroke, treating congestive heart failure (CHF), and delaying the progression of renal disease in animal models. Clinical studies confirm the AII antagonist action of losartan and suggest that losartan will be effective in the treatment of essential HTN. AII antagonism is likely to provide useful treatment in essential HTN and CHF, conditions in which the RAS is known to play a major role. The utility of AII antagonism may extend beyond that of HTN and CHF, as suggested by the potential usefulness of angiotensin-converting enzyme (ACE) inhibition in the treatment or prevention of many other diseases. The key advantage AII antagonists provide over ACE inhibitors is that they may avoid unwanted side effects, related to bradykinin potentiation with the latter drugs. The AII antagonists will help determine the role of the RAS in physiologic regulation and in the pathophysiology of various disease states.

Improvement in exercise tolerance and immediate beta-adrenergic blockade with intranasal propranolol in patients with angina pectoris

A new intranasal spray formulation of propranolol was developed to provide beta-adrenergic blocking medication on an immediate basis to patients with angina pectoris. The effects of this spray or placebo were assessed in 16 patients with effort-induced angina in a blinded, randomized, cross-over design study that compared placebo with intranasal propranolol spray (5 mg/puff) 15 minutes before exercise on a treadmill (Bruce protocol). One week later, each patient, acting as his/her own control, received the alternative treatment and repeated exercise. Mean plasma propranolol level with active therapy was 20 ng/ml. Patients with active spray demonstrated a significant increase in total exercise time than patients taking placebo (530 +/- 197 vs 460 +/- 177 seconds, p = 0.05), an increase in the time to 1 mm ST-segment depression on the electrocardiogram (384 +/- 202 vs 327 +/- 144 seconds, p < 0.05), and an increase in time to onset of angina (452 +/- 149 vs 363 +/- 175 seconds, p = 0.0005). There was a blunting of maximal exercise heart rate with active therapy compared with placebo (120 +/- 13 vs 133 +/- 17 beats/min, p < 0.01), blunting of maximal exercise systolic blood pressure (185 +/- 22 vs 194 +/- 21 mm Hg, p < 0.05), and blunting of peak double product (p < 0.0005), with more modest effects on resting heart rate. Propranolol spray is an effective approach for providing immediate beta blockade and improving exercise tolerance in patients with angina pectoris.

Treatment of myocardial ischemia and myocardial infarction in the elderly

The diagnosis of coronary artery disease in the elderly is problematic because older patients often present atypical symptoms or are asymptomatic. Once coronary disease is diagnosed, the proper course of treatment is not always clear, since few studies have focused on patients older than 65 years. Moreover, older patients often have medical conditions that may aggravate coexisting cardiovascular problems or interfere with conventional pharmacotherapy. For these reasons many physicians who treat cardiovascular problems aggressively in younger patients are reluctant to do so in older individuals. There is considerable evidence, however, that older patients could benefit as much or more from aggressive therapy because of their greater risk of mortality from myocardial ischemia and infarction.

Internal medicine housestaff and attending physician perceptions of the impact of the New York State Section 405 regulations on working conditions and supervision of residents in two training programs

OBJECTIVES

To assess the attitudes of internal medicine housestaff and their attending physicians regarding the impact of the reduction in on-call working hours and increased supervision mandated in New York by a revision of the State Health Code (Section 405).

DESIGN

Survey of senior medical housestaff and attendings two years after the adoption of the mandated changes.

SETTING

Two independent medicine housestaff training programs of the Albert Einstein College of Medicine in the Bronx, New York.

PARTICIPANTS

Fifty-three percent of third- and fourth-year residents (n = 79) and 60% of voluntary and full-time attendings (n = 266) responded.

MEASUREMENTS

A factor analysis of 13 variables that appeared on both versions of the survey identified two interpretable factors. A multivariate analysis of variance compared responses to each factor by group and by campus, and Bonferroni post-hoc comparisons analyzed the items within factors. Chi-square analyses compared responses of residents and attendings to the open-ended questions.

RESULTS

Significant differences between the housestaff and attendings groups were found for all fixed-response items (minimum p < 0.05 for all analyses), but both groups agreed that the regulations had a positive impact on resident attitudes regarding the demands on their time. Both groups were also uncertain whether the new regulations had a beneficial effect on the choice of internal medicine as a career, the quality of resident supervision, and residents' intellectual interest in challenging medical problems. Whereas residents agreed that the regulations diminished their fatigue, had no impact on their ability to observe the full impact of interventions on patients, and resulted in better patient care, attendings were uncertain or disagreed. While attendings agreed that the regulations had caused a shift-work mentality among residents, housestaff were uncertain.

CONCLUSIONS

Housestaff had more positive attitudes about the impact of the mandated changes in working conditions for residents than did attending physicians in the same institutions. The major benefits seen by residents were less fatigue and more spare time. There was no consensus about whether these changes had a positive impact on internal medicine practice and clinical supervision. There was some concern that a shift-work mentality is developing among residents and that continuity of patient care has suffered. Thus, despite some substantial benefits, Section 405 may not be achieving its goals of improving resident supervision and the quality of patient care by houseofficers.

Combination drug therapy with calcium-channel blockers in the treatment of systemic hypertension

Calcium-channel blockers have been shown to be both safe and effective for treatment of patients with systemic hypertension. These drugs reduce peripheral vascular resistance predominantly by the inhibition of transmembrane calcium ion fluxes in vascular smooth muscle, and by this mechanism can reduce elevated blood pressure. To maximize blood pressure lowering efficacy in patients, calcium-channel blockers have also been used in combination with other antihypertensive treatments that have included diuretics, beta-adrenergic blockers, and angiotensin-converting enzyme inhibitors.

Acute hyperglycaemic effect of anaesthetic induction with thiopentone

The acute effects of thiopentone on plasma glucose concentration and regulation in humans have not been well described. We therefore examined the effect of a single dose (6 mg/kg) of thiopentone on plasma glucose, insulin, glucagon, adrenaline and noradrenaline in 16 healthy women undergoing elective abdominal surgery. To assess involvement of the neuroendocrine system in the response to thiopentone, half of the patients received labetalol prior to induction of anaesthesia. Thiopentone injection resulted in a 50% increase in plasma glucose levels (P < 0.001) in both labetalol-treated and non-treated patients 90 s following its administration. This was associated neither with significant increases in plasma glucagon, adrenaline and noradrenaline nor with a decline in plasma insulin. We conclude that acute hyperglycaemia following thiopentone is most likely the consequence of a non-adrenergically-mediated increase in hepatic glucose release.

A new extended-release formulation of diltiazem HCl for the treatment of mild-to-moderate hypertension

Calcium-channel blockers are a safe and effective treatment modality and have been used extensively in the treatment of angina and hypertension. Dilacor XR capsules, a new extended-release formulation of diltiazem, has been developed for the treatment of hypertension. Dilacor XR (Rhône-Poulenc Rorer Pharmaceuticals Inc., Collegeville, PA) uses a novel drug delivery system, the Geomatrix (JAGO Research AG, Zollikon, Switzerland) controlled-release system, to deliver diltiazem at a constant rate for 24 hours. The rate of absorption is also slower. As doses of Dilacor XR were increased from 120 mg to 540 mg/day, there were disproportionate increases observed in area under the curve, maximum peak plasma concentration, minimum peak plasma concentration, and average peak plasma concentration. The efficacy data from two clinical trials have confirmed the established efficacy of diltiazem and the 24-hour efficacy of Dilacor XR in the control of mild-to-moderate hypertension. The incidence of adverse effects with Dilacor XR in doses as high as 540 mg/day was generally comparable to that of placebo. This new extended-release formulation of diltiazem should significantly facilitate blood pressure control because of better patient compliance with a once daily regimen.

Comparison of sustained-release formulations of nicardipine and verapamil for mild to moderate systemic hypertension

In this double-blind, parallel, multicenter study, sustained-release (SR) preparations of 2 calcium antagonists, nicardipine and verapamil, were compared for the treatment of mild to moderate systemic hypertension. Two hundred eighteen patients with supine diastolic blood pressures (BP) 95 to 114 mm Hg were randomly assigned to receive nicardipine-SR 45 mg twice daily (n = 73), nicardipine-SR 60 mg twice daily (n = 73) or verapamil-SR 240 mg once daily in the morning (n = 72). All 3 regimens significantly reduced supine and sitting systolic and diastolic BPs compared with baseline values (p < 0.005). The efficacy of drugs became apparent after 2 weeks of therapy, and was sustained throughout the 12-week study. Reductions in sitting diastolic BP and supine and sitting systolic BPs were statistically greater with nicardipine-SR 60 mg twice daily compared with verapamil, and nicardipine-SR 45 mg twice daily was equivalent to verapamil. Asthenia and constipation occurred more frequently in patients treated with verapamil (9.7 and 11.1%, respectively, compared with 6.8 and 4.1% in either nicardipine group). Adverse events reported more frequently with nicardipine were headache (17.8% with nicardipine-SR 60 mg and 15.1% with nicardipine-SR 45 mg vs 13.9% with verapamil) and edema (15.1% in the nicardipine-SR 60 mg group, 8.2% with nicardipine-SR 45 mg vs 4.2% with verapamil). Verapamil, but not nicardipine, produced significant reductions in heart rate. SR preparations of calcium antagonists offer options for effective monotherapy of systemic hypertension. Side-effect profiles differ and may affect choice of therapy.

Beta-adrenergic blockers as cardioprotective agents

The evidence supporting and describing cardioprotective effects of beta-adrenergic blocker treatment is surveyed. Details of the many studies that individually and collectively document the ability of long-term and acute beta-blocker therapy to reduce overall mortality, sudden cardiovascular death, and nonfatal reinfarction in patients surviving or experiencing a myocardial infarction are described. A discussion of the mechanisms by which beta blockers probably and theoretically achieve these benefits includes the suggestion that they may reduce plaque rupture, thus indirectly inhibiting thrombosis. It is also suggested that, in the future, further cardioprotective benefits may accrue to the use of beta blockers in conjunction with thrombolysis and of beta blockers with a duration of action sustained throughout a full 24 hours.

Tolerance, rebound, and time-zero effect of nitrate therapy

Both nitroglycerin and long-acting nitrates have proved effective in treating acute anginal pain. In recent years, however, development of tolerance with the continuous use of these agents has been documented. A pilot study demonstrated attenuation of the therapeutic effect of high-dose, continuous transdermal nitroglycerin therapy, despite adequate plasma nitroglycerin levels. In a subsequent, larger Transdermal Nitroglycerin Cooperative Study, evidence of tolerance was detected within 24 hours of initiation of continuous nitroglycerin patch therapy at several different dose levels. Sustained pharmacologic activity has been achieved with the intermittent use of transdermal nitroglycerin, usually for 12 hours followed by a 12-hour drug-free period. When the patch is discontinued, however, some patients experience exacerbation, or rebound, of anginal symptoms and a worsening of exercise tolerance at the end of the drug-free period. Additional clinical research is therefore needed to determine the optimal intermittent dosing strategy.

A randomized, placebo-controlled, double-blind comparison of amlodipine and atenolol in patients with essential hypertension

The efficacy and safety of amlodipine (2.5 mg, 5 mg, or 10 mg) once daily was compared with atenolol (50 mg to 100 mg) once daily in patients with mild-to-moderate essential hypertension in a randomized, double-blind, parallel, placebo-controlled study. One hundred and twenty-five patients were randomly allocated at the end of a 4-week run-in placebo period to 8 weeks' double-blind treatment with amlodipine (n = 41), atenolol (n = 43), or placebo (n = 41). The mean changes from baseline in blood pressure 24 h postdose for amlodipine (mean daily dose 8.8 mg) were -12.8/-10.1 mm Hg for supine and -11.5/-9.8 mm Hg for standing blood pressure (P < .001). For atenolol (mean daily dose 83.7 mg) the changes were -11.3/-11.7 mm Hg for supine and -13.3/-12.3 mm Hg for standing blood pressure (P < .001). There were no statistically significant differences between treatments. The responder rates for amlodipine, atenolol, and placebo were 61.1%, 64.9%, and 11.1%, respectively. Determinations taken over the 24-h period at the final visit revealed that amlodipine and atenolol maintained the group mean supine blood pressure at or below 140/90 mm Hg throughout the period of observation; the corresponding time-effect curve for the placebo group was clearly in the hypertensive range. Heart rate was significantly lowered by atenolol only. Both amlodipine and atenolol were well-tolerated. Only one patient was withdrawn because of the development of peripheral edema, arthralgia, and fatigue after treatment with amlodipine. This study demonstrates that once-daily administration of amlodipine or atenolol to mild-to-moderate hypertensive patients was well-tolerated and provided adequate blood pressure control throughout the 24-h dosing interval.

Cardiomegaly on chest x-ray: prognostic implications from a ten-year cohort study of elderly subjects: a report from the Bronx Longitudinal Aging Study

This report is from a 10-year cohort study of community-dwelling elderly men and women. Mean age at the time of entry into the study was 79 years. Annual chest x-ray studies were performed, and data are presented regarding prevalence, incidence, and prognosis of cardiomegaly. Cardiomegaly was defined as a transverse diameter of the cardiac silhouette greater than or equal to 50% of the transverse diameter of the chest (increased cardiothoracic ratio). At the time of entry into the study 110 subjects (23%) had cardiomegaly. After 10 years, 51% of the subjects with cardiomegaly at baseline died compared with 33% of the subjects without cardiomegaly (mortality rate = 9.1 vs 4.8/100 person-years respectively; p = 0.014). Cardiovascular disease incidence was also higher for those with preexisting cardiomegaly at baseline (rate 9.1 vs 6.1/100 person-years; p = 0.0001). According to the Cox proportional hazards regression analysis, age, cardiomegaly, diabetes, and prior evidence of myocardial infarction were independent predictors for death in this cohort. Similarly, the best predictive variables for cardiovascular disease were age, diabetes, prior evidence of myocardial infarction, and cigarette smoking. Of the 359 subjects without cardiomegaly at baseline, 108 (30%) showed evidence of new cardiomegaly, and their risk of cardiovascular disease was 1.8 times that of subjects whose test results were negative for cardiomegaly throughout the study (p = 0.003). Thus cardiomegaly, as defined by an increased cardiothoracic ratio on x-ray films, irrespective of cause, is associated with a poor prognosis in very elderly men and women.

Sustained-release verapamil formulations for treating hypertension

Verapamil, the first calcium-channel blocker to be introduced for clinical use, is a major drug used for the treatment of systemic hypertension. During the past 10 years, the use of verapamil for hypertension has produced a considerable clinical database to support the efficacy and safety of the agent in many patients. Because of its short half-life, verapamil was originally administered 3 to 4 times daily. During the past decade, a sustained-release formulation of verapamil has been marketed in the US. This product allows for once-daily dosing up to 240 mg/d; however, when higher doses are needed, this sustained-release formulation should be administered twice daily. In addition, the medicine should be taken with food to avoid the high peak blood levels of verapamil, which appears to be related to the delivery system. A new pellet-filled capsule formulation of verapamil (Verelan, Lederle, Wayne, NJ and Wyeth-Ayerst, Philadelphia, PA) is available and provides controlled absorption, 24-hour blood pressure control, improved peak-to-trough plasma levels, and once-daily dosing regardless of dosage size. Prolonged-release verapamil can be taken without food.

Comparative efficacy and concomitant use of bepridil and beta blockers in the management of angina pectoris

The efficacy and safety of bepridil hydrochloride (HCl) and propranolol HCl monotherapy were investigated in a double-blind, parallel-group crossover study in 75 patients with chronic stable angina pectoris. For the first double-blind segment, both drugs reduced the frequency of weekly anginal attacks and nitroglycerin consumption. On exercise testing, bepridil was significantly more effective in terms of increasing time to angina and total work. Heart rate and ST-segment depression decreased to a greater degree with propranolol than bepridil. Bepridil produced a greater increase in QT interval than propranolol; corrected QT (QTc) interval was increased by bepridil and slightly decreased by propranolol. The incidence of adverse effects was roughly comparable for the two active drugs and higher than that for placebo during washout periods. It was concluded that bepridil, at a mean maintenance dosage of 324 mg/day, was at least as effective as propranolol in improving exercise tolerance--specifically time to angina and total work--and that tolerability of the 2 drugs was comparable. In another study, the efficacy and safety of bepridil combined with propranolol were compared with that of placebo plus propranolol in 56 patients who had not been well controlled on propranolol alone. The addition of bepridil significantly reduced the frequency of anginal attacks and weekly nitroglycerin consumption compared with baseline. The combination of propranolol and bepridil also produced significant improvements in total exercise time, time to angina, and total work compared with baseline. The QTc interval increased significantly from baseline in the bepridil combination group and decreased significantly in the propranolol plus placebo group.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparative pharmacokinetic and clinical profiles of angiotensin-converting enzyme inhibitors and calcium antagonists in systemic hypertension

Angiotensin-converting enzyme (ACE) inhibitors and calcium antagonists are important classes of antihypertensive agents. Within their respective classes, ACE inhibitors and calcium antagonists share common pharmacokinetic properties, but in contrast to ACE inhibitors, some calcium antagonists may cause a significant increase in plasma digoxin concentrations. Clinically, both classes of agents have been shown to be safe and effective in large-scale, long-term clinical trials. ACE inhibitors appear to be very well tolerated and may be associated with fewer adverse effects than some calcium antagonists. ACE inhibitors appear to blunt diuretic-induced hypokalemia, hypercholesterolemia, hyperuricemia, and hyperglycemia. Both classes of agents can be used safely in patients with renal disease, diabetes mellitus, peripheral vascular disease, and chronic obstructive pulmonary disease. They may also be used in the elderly. While ACE inhibitors are particularly useful in hypertension accompanied by congestive heart failure, calcium antagonists can be very useful when angina pectoris is present in the hypertensive patient.

Hypertension: cardiovascular implications in a cohort of old old

OBJECTIVE

To examine the prevalence and cardiovascular implications of hypertension in advanced age.

DESIGN

Prospective non-interventional study of a fixed cohort of very elderly subjects.

PARTICIPANTS AND SETTING

The subjects were 488 community-dwelling volunteers. Mean age at entry was 79 years (range 75-85). All subjects were ambulatory, non-demented, and free of terminal illness at baseline. Participants were evaluated at the gerontology department of an urban medical school.

MAIN OUTCOME MEASURES

Cardiovascular morbid and mortal events that were followed included fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, and death. Prevalence of unrecognized myocardial infarction defined by electrocardiographic changes was also assessed.

RESULTS

When hypertension was defined by history, current use of medications, or measured elevations in blood pressure, 78% of the subjects could be considered hypertensive. Univariate analysis showed an increased incidence of strokes in subjects with measured hypertension (P = 0.04). Subjects with elevated blood pressure (untreated) were more likely to develop clinically unrecognized myocardial infarction (P = 0.017). Multivariate survival analysis showed hypertension to be a modest predictor of overall cardiovascular disease (P = 0.067) but not of all-cause mortality. Left ventricular hypertrophy was a predictor of cardiovascular disease (P = 0.013) and all-cause mortality (P = 0.008). Age remained a significant risk factor for these endpoints, even in the very old. Isolated systolic hypertension was analyzed separately and in univariate analysis was a risk factor for stroke but not other cardiovascular morbidity.

CONCLUSIONS

Hypertension at advanced age remains a modestly important risk factor in the development of cardiovascular disease.

Plasma lipids and lipoproteins and the incidence of cardiovascular disease in the very elderly. The Bronx Aging Study

The Bronx Aging Study is a 10-year prospective investigation of very elderly volunteers (mean age at study entry, 79 years; range, 75-85 years) designed to assess risk factors for dementia and coronary and cerebrovascular (stroke) diseases. Entry criteria included the absence of terminal illness and dementia. All subjects (n = 350) included in this report had at least two lipid and lipoprotein determinations. Overall, more than one third of subjects showed at least a 10% change in lipid and lipoprotein levels between the initial and final measurements. Moreover, mean levels for women were consistently different than those for men, and because of this finding subjects were classified into potential-risk categories based on the changes observed by using their sex-specific lipid and lipoprotein distributions. The incidences of cardiovascular disease, dementia, and death were compared between risk groups. Proportional-hazards analysis showed that in men a consistently low high density lipoprotein cholesterol level (less than or equal to 30 mg/dl) was independently associated with the development of myocardial infarction (p = 0.006), cardiovascular disease (p = 0.002), or death (p = 0.002). For women, however, a consistently elevated low density lipoprotein cholesterol level (greater than or equal to 171 mg/dl) was associated with myocardial infarction (p = 0.032). Thus, low high density lipoprotein cholesterol remains a powerful predictor of coronary heart disease risk for men even into old age, while elevated low density lipoprotein cholesterol continues to play a role in the development of myocardial infarction in women. The findings suggest that an unfavorable lipoprotein profile increases the risk of cardiovascular morbidity and mortality even at advanced ages for both men and women.

Serum lipids and lipoproteins in advanced age. Intraindividual changes

The Bronx Aging Study is a longitudinal investigation of nondemented, nonterminally ill, community-residing, old old volunteer subjects, designed to assess risk factors for the development of dementia and coronary and cerebrovascular diseases. During the first five annual evaluations, total cholesterol, high-density (HDL) and low-density lipoprotein (LDL), and triglyceride levels were measured. Mean cholesterol values (+/- standard error of the mean) for subjects at baseline were significantly higher for women than for men. Respectively, the values for total cholesterol were 6.1 +/- .1 mm/L (234 +/- 3 mg/dL) and 5.3 +/- .1 mm/L (207 +/- 3 mg/dL); for LDL cholesterol, 4.1 +/- .1 mm/L (158 +/- 2 mg/dL) and 3.7 +/- .1 mm/L (141 +/- 3 mg/dl); and for HDL cholesterol, 1.2 +/- .1 mm/L (47 +/- 1 mg/dL) and 1.0 +/- .1 mm/L (38 +/- 1 mg/dL). Mean triglyceride levels were 1.5 +/- .1 mm/L (135 +/- 5 mg/dL) for women and 1.6 +/- .1 mm/L (138 +/- 5 mg/dL) for men. Further, mean values remained stable over time. However, there was considerable intraindividual change observed in a substantial proportion of subjects between initial and final determinations. Changes of at least 10% from baseline were observed in 41%, 63%, 52%, and 78% of the cohort for cholesterol, HDL, LDL, and triglycerides, respectively. Thus, single measurements appear inadequate for establishing a diagnosis of hyperlipidemia in the elderly.