Current status of antihypertensive therapy for elderly patients in Japan

To assess how elderly Japanese hypertensive patients are treated by specialists, we conducted a cross-sectional survey. A total of 1,163 outpatients aged 50 years or older were studied. Hypertension was diagnosed in 939 of these patients, and 827 were receiving drug therapy. The average blood pressure during therapy was 143 +/- 16/81 +/- 10 mmHg. In patients aged 70 years or older, systolic blood pressure during antihypertensive therapy was significantly higher (p < 0.01) and diastolic blood pressure was significantly lower (p < 0.01) than the corresponding values in those aged 50 to 59 years or 60 to 69 years. The calculated mean blood pressures were similar in the different age groups. The rate of monotherapy in the patients aged 70 years or older was 58.8%, which was significantly higher (p < 0.01) than the rates of monotherapy in the other age groups. Calcium channel blockers were prescribed in about 80% of patients, irrespective of age or comorbidity. Of the patients receiving calcium channel blockers, 43.5% were treated with monotherapy. This rate significantly (p < 0.01) increased with advancing age. Diastolic blood pressures were significantly lower (p < 0.05) in patients with stroke and in those with ischemic heart disease, diabetes mellitus, or dyslipidemia, as compared with patients with no comorbidity. Among patients aged 70 years or older, the difference in systolic blood pressure between those with ischemic heart disease and those with no comorbidity was not significant. Blood pressure in elderly hypertensive patients was reduced to a level similar to that in younger patients. The target blood pressure was influenced by the presence of comorbidity. Furthermore, specialists showed a high preference for the use of calcium channel blockers in the management of hypertension.     

Cardiovascular care with the new T-type calcium channel antagonist: possible role of attendant sympathetic nervous system inhibition

DIFFERENCES AMONG TYPES OF CALCIUM ANTAGONISTS: Calcium antagonists lower blood pressure, relieve angina pectoris and improve chronic heart failure, primarily through peripheral and coronary vasodilation. The debate as to whether short-acting, long-lasting (L)-channel calcium influx antagonists of the 1,4-dihydropyridine type might be involved in excess cardiac mortality has raised new controversies with respect to the cardiac morbidity and mortality outcome for all calcium antagonists. Different pharmacodynamic effects (short-acting vasodilation inducing pulsatile sympathetic reflex stimulation) may explain differences in outcome with calcium antagonist therapies. Calcium antagonists also differ in their direct effects on the sympathetic nervous system, and on its long endocrine arm, the renin-angiotensin-aldosterone system. These differential effects relate to the cardiac conduction system and ventricular ectopic activity, to cardiac and vascular remodelling and hypertrophy, and perhaps also to the development of hypertension. L-CHANNEL CALCIUM ANTAGONISTS: Depending on their pharmacodynamic characteristics, L-channel calcium antagonists of the dihydropyridine, verapamil or diltiazem type reflexly activate the sympathetic nervous system and blunt beta-adrenoceptor-mediated calcium influx, thus eliciting negative inotropy and activation of the renin-angiotensin system. Both verapamil and diltiazem slow down pacemaker activity and atrioventricular conduction. MIBEFRADIL: The new-class T-channel blocker mibefradil exhibits vascular selectivity and induces peripheral and coronary vasodilation. There is no reflex sympathetic activation and no negative inotropic effect. It increases coronary blood flow without increasing oxygen consumption and causes a slight slowing of the heart rate, thereby inducing diastolic relaxation. The latter improves subendocardial and small artery perfusion. There is a sympatholytic effect, owing to T-channel expression in neurones, sinoatrial and atrioventricular nodes and Purkinje fibres. In experimental models, ventricular ectopic activity is reduced with mibefradil. The renin-angiotensin-aldosterone system and endothelin effects are blunted by T-channel inhibition. These and other factors reduce smooth muscle cell proliferation, hypertrophy and matrix deposition. T-type calcium channel inhibition, over and above its antihypertensive and anti-ischaemic effects, and afterload-reducing effects in chronic heart failure, offers the potential for a cardiovascular protective benefit, which may be critically related to interference with the sympathetic nervous system.     

Antihypertensive therapy. Angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, and calcium antagonists

ACEIs, angiotensin II receptor antagonists, and calcium antagonists are effective and well-tolerated antihypertensive agents but, except in special situations, should be considered alternative drugs for first line therapy until randomized trials show that they are at least as effective as diuretics and beta-blockers in preventing cardiovascular morbidity and mortality for a broad spectrum of hypertensive patients. ACEIs are particularly indicated for managing patients with congestive heart failure due to systolic dysfunction and patients with diabetic nephropathy, especially in Type I diabetes. Theoretically, the AII receptor antagonists will be equally effective for these indications, and randomized trials are now underway to demonstrate this. Special indications for calcium antagonists in the management of hypertension include angina pectoris, and for the non-dihydropyridine calcium antagonists, paroxysmal supraventricular tachycardia, and atrial fibrillation with rapid ventricular rate. Isolated systolic hypertension in the elderly is a special indication for long-acting dihydropyridine calcium antagonists, although diuretics are preferred. Calcium antagonists have been particularly effective in managing hypertension induced by cyclosporine. They are contraindicated in CHF due to systolic dysfunction and in the management of acute myocardial infarction. The long-term cardioprotective effect of calcium antagonists after a myocardial infarction has been demonstrated only for verapamil and diltiazem in patients with no evidence of LV dysfunction during their infarction. Calcium antagonists should be prescribed for this purpose only when beta-blockers are poorly-tolerated or contraindicated.     

Which calcium antagonists for hypertension?

Calcium antagonists have been used for treatment of cardiovascular diseases for more than 25 years. Several recent retrospective studies have suggested that chronic treatment with short-acting dihydropyridines increased the incidence of cardiac events, cancer and gastrointestinal bleedings. Randomized prospective studies have, however, never been able to confirm these observations. In addition, well-conducted studies using verapamil and diltiazem have suggested that these calcium antagonists may even improve cardiovascular mortality and morbidity of the hypertensive patient. There is therefore no reason to believe that the questionable results derived from retrospective studies of the effects of short-acting calcium antagonists on cardiac and noncardiac events may apply to the newer generation of long-acting calcium antagonists.     

Antidepressant efficacy and cardiovascular safety of venlafaxine in young vs old patients with comorbid medical disorders

OBJECTIVE: To determine whether venlafaxine exerts a differential effect on blood pressure in young versus old depressed patients. METHOD: We compared thirty-four consecutive patients treated with 50-250 mg/day venlafaxine for major depressive disorder or another major mood disorder at our medical college's ambulatory neuropsychiatry program. We obtained baseline and follow-up blood pressure measurements. Each patient also received a baseline and final Clinical Global Impressions (CGI) score; global improvement was determined by consensus of two clinicians. RESULTS: Sixteen nongeriatric patients (age, 13 to 56 years) were compared with eighteen elderly patients (age, 65 to 86 years). Most patients (88%) had serious medical comorbidities or histories. Despite a higher mean daily venlafaxine dosage for patients in the young group, no significant changes in systolic blood pressure were noted in either group. For the older group, we found a non-statistically significant 4.7 mm Hg mean increase in diastolic blood pressure. No patient became hypertensive. We also found a negative correlation between baseline diastolic blood pressure and change in diastolic blood pressure during treatment with venlafaxine. This inverse relationship was statistically significant in the older patients. CONCLUSIONS: Venlafaxine was not associated with significant, sustained changes in blood pressure in any patient receiving dosages of 50-250 mg/day. Minimal changes in diastolic blood pressure were no more likely to occur in older venlafaxine-treated patients than in younger ones. Higher baseline diastolic blood pressure in older patients, but not in younger ones, seemed to protect against diastolic adrenergic blood pressure effects of venlafaxine.     

Graduate education in primary care: the challenge

One can summarize the current status of calcium antagonists to treat heart failure as follows: Usually there is a favorable acute response to these drugs in heart failure patients but long-term effects in the patients treated with nifedipine, diltiazem, and verapamil have produced rather disappointing results. Thus, they should not be used routinely in heart failure patients. Their main problems were related to the negative inotropic effects of the drugs, the lack of reduction in ventricular filling pressure, and activation of the neurohumoral systems which have an adverse effect on cardiovascular performance, for example, renin-angiotensin. In contrast, the second-generation calcium antagonists have more selective vasodilating properties and fewer negative inotropic properties, which, I believe, justifies their use in selected heart failure patients. Unfortunately, there are no large randomized controlled long-term trials to evaluate morbidity and mortality in heart failure patients treated with these agents. One can rationalize that the symptomatic elderly patient with isolated diastolic dysfunction can be treated effectively with calcium antagonists but, once again, there are no major trials evaluating any drug in the management of patients with isolated diastolic function not due to hypertrophic cardiomyopathy. Rationale for using calcium antagonists could be best supported in patients with active ischemic heart disease and symptoms of heart failure. In this instance the coronary vasodilator effects may relieve myocardial ischemia and, by that mechanism, improve myocardial systolic and diastolic function.     

Regression of cardiac hypertrophy by 1,4 dihydropyridines in hypertensive patients

BACKGROUND: Left ventricular hypertrophy (LVH) represents an important intermediate end-point for, for example, the progression to heart failure. The persistence or progression of LVH despite antihypertensive therapy probably reflects the persistence or activation of mechanisms that negatively affect the cardiovascular system and, consequently, long-term outcome. EFFECT OF MODERN ANTIHYPERTENSIVE AGENTS: Long-term treatment with rapid-onset (and usually short-acting) dihydropyridine calcium antagonists is significantly less effective than angiotensin converting enzyme (ACE) inhibition in reducing left ventricular mass (LVM) in hypertensive patients. Both intermittent, and probably only partial, blood pressure control and an increase in sympathetic activity resulting from rapid decreases in blood pressure following dosing with such calcium antagonists may contribute to this relative ineffectiveness. In contrast, more recent studies have demonstrated that the longer acting dihydropyridines can reduce LVM as effectively as ACE inhibitors. DISTINCTIONS AMONG DIHYDROPYRIDINE CALCIUM ANTAGONISTS: Among the 1,4-dihydropyridines, drugs such as amlodipine and nifedipine in the gastrointestinal therapeutic system (GITS) maintain good blood pressure control over the full 24-h dosing period and do not cause dose-related increases in sympathetic activity. In contrast, extended-release felodipine has been shown to provide only intermittent blood pressure control, still leading to sympathetic activation. Notably, during short periods of noncompliance, blood pressure control is maintained with intrinsically long-acting agents such as amlodipine but not with slow-release formulations of short-acting agents such as nifedipine GITS. CONCLUSIONS: It is possible that the rate of onset and duration of action of various dihydropyridines may be pivotal factors in determining their effects on cardiovascular outcomes. Thus, the least beneficial dihydropyridines may be rapid-onset, short-acting agents, such as nifedipine capsules, and the most beneficial may be the slow-onset, long-acting agents such as amlodipine.     

Managing the elderly hypertensive patient beyond blood pressure reduction

ANTIHYPERTENSIVE TREATMENT OF THE ELDERLY: Several prospective, randomized, long-term trials on antihypertensive drug treatment have shown that elderly patients with systolic and diastolic or isolated systolic hypertension benefit from a reduction in blood pressure. Antihypertensive treatment reduces the overall mortality by 20%, cardiovascular mortality by 33%, the incidence of fatal and non-fatal cerebrovascular events by 40% and the complications of coronary heart disease by 15%. In addition, elderly patients have a high risk of overt or latent and asymptomatic cardiovascular diseases. For this reason, not only antihypertensive treatment, but also risk factor modification (such as cholesterol reduction therapy) is, in absolute terms, more beneficial in elderly patients than in middle-aged patients, particularly in patients with concomitant cardiovascular diseases and other risk factors. QUALITY OF LIFE: Although the randomized trials have focused on mortality and morbidity as main endpoints, it is questionable whether longevity is a worthwhile social objective in itself. Quality of life is an important aspect of antihypertensive treatment, since hypertension is generally symptomless while drug therapy may have adverse effects on the quality of life. The frequency of adverse effects is similar in both middle-aged and elderly hypertensive patients, with about 2% of patients per year in both age groups withdrawing from randomized treatment due to objectively assessed adverse effects. The rate of subjectively assessed adverse effects during treatment is also similar in younger and elderly patients. In general, clinical studies have suggested that a blood pressure reduction does not influence the well-being of elderly patients, whether measured in physical, emotional or social terms. Both calcium antagonists and diuretics have shown an age-dependent effect in comparative trials, with a higher blood pressure reduction in elderly than in younger patients. CONCLUSION: Antihypertensive therapy in elderly hypertensives adds longevity and need not compromise quality of life. Although the reduction and normalization of blood pressure is the primary goal, the increased availability of antihypertensive preparations and drugs for treating concomitant diseases and risk factors allows the physician to tailor treatment of the elderly to the needs of the individual patient.     

Hypertension in the elderly: age- and disease-related complications and therapeutic implications

Effective treatment of hypertension in the elderly requires an understanding of both the progressive course of the disease and the impact of aging on the cardiovascular system, including physiological, genetic, lifestyle, and environmental factors. Review of the literature that has attempted to define the impact of an "aging process" on cardiovascular structure and function reveals a diversity of findings and interpretations. However, in general, normotensive elderly subjects exhibit the heart and vascular characteristics of "muted" hypertension, including many features of younger hypertensive patients: cardiac hypertrophy, diminution in resting left ventricular early diastolic filling rate, increased arterial stiffness and aortic impedance, diminution in the baroreceptor reflex, a diminished response to catecholamines and diminished renal blood flow, and an increase in peripheral vascular resistance (PVR). Treatment of elderly hypertensives is more challenging because of the greater likelihood of the presence of concomitant diseases, most importantly, coronary and peripheral atherosclerosis, renal dysfunction, and diabetes mellitus. Isolated systolic hypertension (ISH), the most common form of hypertension in the elderly, has also been clearly shown to be an important predictor of cardiovascular morbidity and mortality, including coronary artery disease, congestive heart failure, and stroke. Treatment of ISH has been shown to lower systolic pressure safely and effectively in the elderly. By reducing PVR, and possibly the arterial stiffness, and thus the early reflected pulse waves, vasodilators, including calcium antagonists, may lower these three components of arterial impedance, and hence lower the arterial load on the heart. The cardiac hypertrophy and reduced left ventricular filling rate associated with hypertension in older individuals can also be ameliorated, to some extent, by calcium channel blockers.     

Rationale and design of the International Verapamil SR/Trandolapril Study (INVEST): an Internet-based randomized trial in coronary artery disease patients with hypertension

OBJECTIVES: The primary objective of the International Verapamil SR/Trandolapril Study (INVEST) is to compare the risk for adverse outcomes (all-cause mortality, nonfatal myocardial infarction [MI] or nonfatal stroke) in hypertensive patients with coronary artery disease (CAD) treated with either a calcium antagonist-based or a noncalcium antagonist-based strategy. BACKGROUND: Treatment recommendations for hypertension include initial therapy with a diuretic or beta-adrenergic blocking agent, for which reductions in morbidity and mortality are documented from randomized trials but are less than expected from epidemiologic data. For this reason, recent attention has focused on calcium antagonists or angiotensin-converting enzyme inhibitors. While these agents reduce blood pressure, outcome data from large randomized trials are lacking, but some case-control data, dominated by short-acting dihydropyridines, suggest an increased risk of cardiovascular events. These studies had methodologic limitations and did not differentiate among calcium antagonist types and formulations. Several studies differentiating among calcium antagonist types and an overview of published randomized trials show no increased risk with verapamil and suggestion for benefit in CAD patients. METHODS: A total of 27,000 CAD patients with hypertension will be randomized at 1,500 primary care sites to receive either a calcium antagonist-based (verapamil) or beta-blocker/diuretic-based (atenolol/hydrochlorothiazide) antihypertensive care strategy. The study uses a novel, electronic "paper-less" system for direct on-screen data entry, randomization and drug distribution from a mail pharmacy linked to the coordination center via the Internet. RESULTS: Contract negotiations with the United States and international sites are ongoing. Patients being enrolled are predominantly elderly (72% aged 60 years or older) men (54%), with either an abnormal coronary angiogram or prior MI (71%). In addition to hypertension, CAD and elderly age, most patients (89%) have one or more associated conditions (diabetes, dyslipidemia, smoking, cerebral or peripheral vascular disease, etc.) contributing to increased risk for adverse outcome. While 26% have diabetes, most of these are noninsulin dependent. Using the protocol strategies, target blood pressures (according to JNC VI) have been reached in 58% at the fourth visit, and as expected most (89%) are requiring multiple antihypertensive drugs. CONCLUSION: The design and baseline characteristics of the initial patients recruited for a prospective, randomized, international, multicenter study comparing two therapeutic strategies to control hypertension in CAD patients are described.     

Changes in maternal cardiovascular parameter during tocolysis and in the dorsal position shock syndrome (author's transl)

Maternal circulatory parameters and fetal heart rate were measured in 25 healthy pregnant women in the last trimenon during treatment with Fenoterol, Fenoterol in combination with Verapamil and Verapamil alone. Dosages were used in accordance with the tocolytic guidelines from Weidinger and Wiest. We were able to demonstrate that the betamimetic Fenoterol alone and in combination with the Ca++-antagonist Verapamil strongly increases the maternal heart rate an the maternal cardiac output whereas the peripheral resistance decreases accordingly. The average blood pressure stayed leveled, so that a decreased uterine blood flow cannot be assumed under betamimetics from the maternal cardiovascular point of view. However, there are indications for an increased placental blood flow during tocolysis. The betamimetic drug show no significant effect on the fetal heart rate. Additional application of the Ca++-antagonist Verapamil during tocolysis with Fenoterol (in dosages usually used for tocolysis) doesn't change cardiovascular reactions caused by Fenoterol. Change in position from supine to left lateral position caused a short term increase in the maternal cardiac output even noted in pregnant women without a clinically observed cavasyndrom. These changes of maternal cardiac output are comparable with those in orthostatic stress situations.     

Effects of a prosthetic dental device used to treat obstructive sleep apnea syndrome, and compliance of patients using the device

OBJECTIVE: To determine whether older persons with hypertension who use specific calcium antagonists and ACE inhibitors have a different risk of mortality than those using beta-blockers. DESIGN: A prospective cohort study continuing from 1988 through 1992. SETTING: Three communities of the Established Populations for Epidemiologic Studies of the Elderly. PARTICIPANTS: Hypertensive participants aged > or = 71 years (n = 906) who had no evidence of congestive heart failure and who were using either beta-blockers (n = 515), verapamil (n = 77), diltiazem (n = 92), nifedipine (n = 74), or ACE inhibitors (n = 148). Nifedipine was of the short acting variety. MEASUREMENTS: The main outcome measure was all-cause mortality. Age, gender, smoking, HDL-cholesterol, blood pressure, intake of digoxin and diuretics, physical disability, self-perceived health, and comorbid conditions were examined as confounders. RESULTS: During 3538 person-years of follow-up, 188 participants died (53 deaths per 1000 person-years). Compared with beta-blockers, after adjusting for age, gender, comorbid conditions and other health-related factors, the relative risks (95% confidence interval) for mortality associated with use of verapamil, diltiazem, nifedipine, and ACE inhibitors were 0.8 (0.4-1.4), 1.3 (0.8-2.1), 1.7 (1.1-2.7), and 0.9 (0.6-1.4), respectively. The results were unchanged after excluding participants with other potential contraindications to beta-blockers and after stratifying on coronary heart disease and use of diuretics. Higher doses of nifedipine were associated with higher mortality. CONCLUSION: Compared with beta-blockers, use of short acting nifedipine was associated with decreased survival in older hypertensive persons. However, selective factors influencing the use of specific drugs in higher risk patients could not be completely discounted, and final conclusions will depend on clinical trials.     

Calcium antagonists and mortality risk in men and women with hypertension in the Framingham Heart Study

BACKGROUND: Several recent studies have suggested that calcium antagonist drugs, which are widely used for the treatment of hypertension, are associated with increased risk of cardiovascular disease. These studies have cast doubts on the long-term safety of calcium antagonists. OBJECTIVE: To examine the association of calcium antagonist use with mortality in subjects with hypertension followed up in the Framingham Heart Study. SUBJECTS AND METHODS: We stratified 3539 subjects (mean+/-SD age, 64+/-13 years) from the Framingham Heart Study who had hypertension at routine clinic examinations, according to the use of calcium antagonists and presence of coronary heart disease at the baseline examination. At each follow-up examination (every 2-4 years), subjects were reclassified with regard to the use of calcium antagonists. The end point of the study was all-cause mortality. Hazard ratios and 95% confidence intervals associated with the use of calcium antagonists were obtained using Cox proportional hazards regression models. RESULTS: There were 970 deaths during follow-up. Hazard ratios for mortality associated with the use of calcium antagonists were 0.93 (95% confidence interval, 0.72-1.21; P=.59) for subjects with hypertension without coronary heart disease, and 0.92 (95% confidence interval, 0.69-1.24; P=.58) for those with coronary heart disease at baseline. All models were adjusted for age, sex, current smoking, systolic and diastolic blood pressure, use of beta-blockers, and use of other antihypertensive medications. CONCLUSIONS: In this cohort of 3539 subjects with hypertension there were no differences in mortality among subjects with hypertension using a calcium antagonist compared with those who were not. Results were similar among subjects with hypertension with and without coronary heart disease. The results of ongoing long-term, randomized clinical trials will provide more definitive data on the safety of calcium antagonists.     

Pain mapping during minilaparoscopy in infertile patients without pathology

Multiple myeloma (MM) typically afflicts elderly patients with a median age of 65 years. However, while recently shown to provide superior outcome to standard treatment, high-dose therapy (HDT) has usually been limited to patients up to 65 years. Among 550 patients with MM and a minimum follow-up of 18 months, 49 aged >/=65 years were identified (median age, 67; range, 65 to 76 years). Their outcome was compared with 49 younger pair mates (median, 52; range, 37 to 64 years) selected among the remaining 501 younger patients (<65 years) matched for five previously recognized critical prognostic factors (cytogenetics, beta2-microglobulin, C-reactive protein, albumin, creatinine). Nearly one half had been treated for more than 1 year with standard therapy and about one third had refractory MM. All patients received high-dose melphalan-based therapy; 76% of the younger and 65% of the older group completed a second transplant (P =.3). Sufficient peripheral blood stem cells to support two HDT cycles (CD34 > 5 x 10(6)/kg) were available in 83% of younger and 73% of older patients (P =.2). After HDT, hematopoietic recovery to critical levels of granulocytes (>500/microL) and of platelets (>50,000/microL) proceeded at comparable rates among younger and older subjects with both first and second HDT. The frequency of extramedullary toxicities was comparable. Treatment-related mortality with the first HDT cycle was 2% in younger and 8% among older subjects, whereas no mortality was encountered with the second transplant procedure. Comparing younger/older subjects, median durations of event-free and overall survival were 2.8/1.5 years (P =.2) and 4.8/3.3 years (P =.4). Multivariate analysis showed pretransplant cytogenetics and beta2-microglobulin levels as critical prognostic features for both event-free and overall survival, whereas age was insignificant for both endpoints (P =.2/.8). Thus, age is not a biologically adverse parameter for patients with MM receiving high-dose melphalan-based therapy with peripheral blood stem cell support and, hence, should not constitute an exclusion criterion for participation in what appears to be superior therapy for symptomatic MM.     

Influence of risk factors and pharmacological treatment on mortality in patients with essential hypertension

BACKGROUND: The V JNC consensus stated that although new antihypertensive agents, such as angiotensin converting enzyme inhibitors and calcium channel blockers, are considered safer drugs, there is no firm evidence from large controlled trials that these drugs are associated with a lower cardiovascular mortality. AIM: To study the association between cardiovascular risk factors, blood pressure levels, pharmacological treatment and mortality in a group of hypertensive patients followed at an hypertension outpatient clinic. PATIENTS AND METHODS: Patients with essential hypertension were treated with different antihypertensive medications, according to physicians criteria, and controlled until death or loss from follow up. Causes of death were obtained from hospital records and death certificates. Survival was analyzed using life tables, comparisons between groups of patients were done using chi square or a Cox's proportional hazards model. RESULTS: Three hundred thirty-nine hypertensive patients aged 33 to 80 years old were followed for a mean period of 9.8 +/- 4.9 years. Eighty-six were treated with beta blockers, 64 with diuretics, 133 with calcium antagonists and 56 with ACE inhibitors. Blood pressure dropped similarly with all medications. During follow up, 79 patients died. Life table analysis showed that patients with a history of angina, diabetes or myocardial infarction had higher mortality rates. Similarly, patients treated with beta blockers and diuretics had higher mortality than patients treated with calcium antagonists or angiotensin converting enzyme inhibitors. The proportional hazards model showed that the effect of treatment modality persisted after correction for the other risk factors for mortality. CONCLUSIONS: In this series of hypertensive patients, those treated with beta blockers or diuretics had higher mortality rates than those receiving calcium channel antagonists or angiotensin converting enzyme inhibitors.     

Tissue selectivity of calcium channel blockers

Calcium channel blockers are also termed calcium antagonists or calcium entry blockers. The use of calcium antagonists for the management of hypertension is well established. Their control of vascular tone is related to their interaction with the alpha 1 subunit of L-type calcium channels. This interaction is not simple since prolonged depolarisation promotes the inactivated state of the channels resulting in a change of affinity which is different for various molecules so far considered. The isoforms of alpha 1 subunits and the duration of the stimulus required to activate heart or vessels are important parameters to be considered with the nature of the molecule. Those parameters influence the vascular selectivity which is quantified as the ratio of the concentrations required to reduce by 50% the contraction of heart and of vessels. This selectivity is an important component in the therapeutic action. Another component of this action is the prevention of structural changes noted in heart and arteries. As well as lowering blood pressure, calcium channel blockers have also been found to exert blood pressure independent effects. For instance, they reduce cardiac and vascular hypertrophy and avoid renal damage. In the stroke-prone rat, such protective effects are accompanied by reduction of the salt-dependent overexpression of the gene of endothelin-1 and of fetal genes associated with cardiac hypertrophy. This paper summarizes available information about those components and discuss their significance.     

Modern trends in the treatment of hypertension

The main problem of treatment of hypertension in this country as well as abroad is the fact that only less than one quarter of hypertensive patients are treated effectively and have thus normal blood pressure readings. More effective treatment of hypertension is thus one of the main tasks of health care systems in different countries. The objective of treatment of hypertension is to achieve a normal blood pressure. Evidence has been provided that diuretics and beta-blockers markedly reduce cerebrovascular and cardiovascular mortality, in particular in the elderly. ACE inhibitors are the drugs of choice in patients with heart failure or asymptomatic left ventricular dysfunction and in patients with diabetic nephropathy. Unsuitable for treatment of hypertension are short acting calcium channel blockers, in particular nifedipine. On the other hand, long-acting calcium channel blockers reduce the cerebrovascular mortality in elderly hypertensive patients. A number of questions still remain the subject of research: a) should diastolic pressure be reduced to values lower than 90 mm Hg; so far it is necessary only in hypertensive subjects with diabetes mellitus and in juvenile hypertensives; b) is the influence of new groups of antihypertensive drugs, in particular calcium channel blockers, similar, better or worse than that of diuretics and beta-blockers in the prevention of cardiovascular and cerebrovascular morbidity and mortality?; c) is it wise to recommend acetylsalicylic acid also to hypertensive patients without clinical signs of IHD or atherosclerotic affection of other vessels?; d) what is the value of combined antihypertensive and hypolipidaemic pharmacological treatment? Will this combination be not much more valuable in the prevention of IHD?; e) is the prognosis of hypertensive subjects with left ventricular hypertrophy better when ACE inhibitors are used as compared with other antihypertensive drugs?; f) do ACE inhibitors influence the prognosis of diabetic patients more favourably than beta-blockers?     

Paediatric rheumatology: clinical practice review. Physiotherapy and occupational therapy for juvenile chronic arthritis: custom and practice in five centres in the UK, USA and Canada

Calcium channel blockers can block calcium signals that trigger cell differentiation and apoptosis, which are important mechanisms of cancer growth regulation. To ascertain whether calcium channel blocker use was associated with an increased risk of cancer, 750 hypertensive persons age > or = 71 years, with no history of cancer at baseline, were followed from 1988 through 1992. The patients were using either beta-blockers, angiotensin converting enzyme inhibitors or calcium channel blockers (verapamil, nifedipine, and diltiazem; mainly of the short-acting variety). Compared to beta-blockers (n = 424, 28 events), after adjusting for age, gender, race, smoking, body mass index, and number of hospital admissions not related with cancer, the relative risks of cancer (95% confidence interval) for angiotensin converting enzyme inhibitors (n = 124, 6 events) and calcium channel blockers (n = 202, 27 events) were 0.73 (0.30 to 1.78) and 2.02 (1.16 to 3.54), respectively. These findings indicate that calcium channel blocker therapy might increase the risk of cancer. New data are needed in patients using modern calcium channel blocker agents with more gradual absorption. This report should encourage further study of cancer outcomes in elderly patients who are vulnerable to cancer and who are receiving calcium channel blockers.     

Impaired coronary sensitivity to diltiazem in experimental heart failure: involvement of the cyclooxygenase but not the nitric oxide-synthase pathway

Because controversies surround the increased negative inotropic effects of calcium antagonists in heart failure, other mechanisms may explain their lack of efficacy in this condition. We hypothesized that altered coronary sensitivity through endothelial dysfunctions may be involved. Our goal was to evaluate the effects of heart failure on coronary and cardiac sensitivity to the calcium antagonist diltiazem. Left ventricular developed pressure (LVP) and coronary flow (CF) were assessed in isovolumetrically beating, perfused, failing hearts from cardiomyopathic hamsters (UM-X7.1) and hearts from normal hamsters. Diltiazem concentration-response curves for both coronary dilation and its negative inotropic effects were charted under control conditions and in the presence of the specific nitric oxide (NO) synthase inhibitor, NG-nitro-L-arginine methyl ester (L-NAME, 30 microM), and the cyclooxygenase inhibitor, indomethacin (10 microM). Diltiazem concentration-response curves for its negative inotropic action were similar in normal and failing hearts (IC50 1.2 and 2.3 microM, respectively). In contrast, the coronary dilator effects of diltiazem were impaired in failing hearts (EC50 for diltiazem-induced coronary dilation increased from 90 nM in normal hearts to 1.1 microM in failing hearts, p < 0.01). The involvement of endothelial dysfunctions in the observed coronary "desensitization" to diltiazem in heart failure was evaluated through the NO-synthase and cyclooxygenase pathways. Diltiazem concentration-response curves from failing hearts were not modified in the presence of L-NAME, whereas indomethacin normalized the coronary response to diltiazem in heart failure. These findings suggest that coronary "desensitization" to diltiazem occurs through parallel production and/or release of a vasoconstricting factor or factors originating from the cyclooxygenase pathway. Heart failure was not associated with increased cardiac sensitivity to diltiazem but rather with altered coronary sensitivity. These findings suggest that coronary desensitization may play a role in the lack of efficacy of diltiazem in heart failure and provide a better understanding of factors modulating the effects of calcium antagonists in heart failure.