Biomedical subjects

J M Neutel

Publications and source records attributed to J M Neutel.

79 records · Page 5Linked to original sources

PubMed1989

Hypertension in the aged: a pathophysiologic basis for treatment.

According to major surveys, hypertension is found in over half the population aged 65 years or over. In this age group, systolic blood pressure is at least as important as diastolic blood pressure as a predictor of cardiovascular morbidity and mortality. Overall, the presence of hypertension is associated with approximately a threefold increase in the likelihood of major events. Differing factors contribute to the hypertension. Loss of proximal arterial compliance, affecting the larger conduit vessels, occurs often with aging and explains the tendency for systolic pressure to increase while diastolic pressure remains constant or even decreases. A loss of baroreceptor sensitivity also may contribute to hypertension. There is an increase in responsiveness of the sympathetic nervous system and an enhanced sensitivity to its effects in the elderly, perhaps reflecting a decline in the buffering activity of peripheral vascular beta receptors. It is possible, too, that sodium retention may contribute to hypertension in some older patients. Although diuretics traditionally have been the mainstay of treatment in these patients, it is now recognized that other classes of antihypertensive agents may be equally as effective yet less prone to metabolic or symptomatic adverse events. Sympatholytic drugs, calcium channel blockers and angiotensin-converting enzyme inhibitors, either as monotherapy or in combination with low-dose diuretics, have been shown to be efficacious in the elderly. These agents also can produce regression of left ventricular hypertrophy, an additional property that may contribute to a reduction in serious cardiac complications.

Age Factors↗

PubMed1987

Apical hypertrophic nonobstructive cardiomyopathy in a pilot.

Apical hypertrophic cardiomyopathy is a form of nonobstructive hypertrophic cardiomyopathy characterized by disproportionate hypertrophy of the left ventricular apical region. With increasing reports of apical hypertrophic cardiomyopathy appearing in the literature, this condition is certain to be diagnosed amongst airmen. The question of flying status in these pilots may create a problem for the flight surgeon. We present a pilot with clinical and morphological features typical of apical hypertrophic cardiomyopathy who has remained asymptomatic over a 15-year follow-up period. There appears to be a spectrum of severity in apical hypertrophic cardiomyopathy ranging from mild to severe. Those having the mild form of the disease may be considered for restricted licensing subject to having a normal exercise test and no significant arrhythmias on 24-h ambulatory electro-cardiogram. If licensed, review by a cardiologist should be required every 6 months.

Adult↗

PubMedDate not supplied

Optimization of antihypertensive therapy with a novel, extended-release formulation of diltiazem: results of a practice-based clinical study.

Although the effectiveness of diltiazem for the treatment of patients with hypertension has been well demonstrated in numerous placebo-controlled and comparative clinical trials, most physicians have had some concern about its efficacy and have used it predominantly in patients with mild hypertension. Few large-scale studies have evaluated the efficacy and safety of higher dosages of diltiazem for the treatment of patients with hypertension, and few have evaluated the use of diltiazem in patients with more severe hypertension. Tiazac (Forest Pharmaceuticals, Inc., St. Louis, Missouri), a new, extended-release formulation of diltiazem, provides 24-hour blood pressure control with a single daily dose of up to 360 mg. The Study of Titration and Response to Tiazac (START) is an ongoing practice-based, open-label, multicenter study designed to evaluate the efficacy and safety profiles of Tiazac at greater-than-traditional doses in hypertensive patients and to assess the ability of Tiazac to decrease the rate-pressure product, a surrogate marker for cardiac workload. Patients were eligible for study entry whether their hypertension was newly diagnosed or previously treated with a different formulation of diltiazem or any other antihypertensive agent. Normotensive (sitting diastolic blood pressure [SDBP] < 90 mm Hg) subjects and those with mild (SDBP 90 to 99 mm Hg), moderate (SDBP 100 to 109 mm Hg), severe (SDBP 110 to 119 mm Hg), and very severe (SDBP > or = 120 mm Hg) hypertension were assessed at baseline (visit 1), visit 2 (10 to 14 days after visit 1), and visit 3 (25 to 28 days after visit 1). A total of 3082 patients were enrolled, and data from 2802 assessable patients (i.e., those who completed visits 1, 2, and 3) were analyzed. No subjects were lost to follow-up as a result of adverse effects. All subjects received a starting dose of Tiazac 180 mg or 240 mg once daily, and doses were titrated upward to 360 mg once daily as clinically indicated. Blood pressure reduction matched the severity of hypertension in all patients. Subjects who were switched from another diltiazem formulation demonstrated further decreases in SDBP. Antihypertensive monotherapy with Tiazac was well tolerated. This interim START report demonstrates that a daily dose of up to 360 mg of diltiazem is optimal in terms of both control of hypertension and patient compliance. It also provides the practice-based physician with useful clinical information on dose titration and response to a new formulation of an approved drug and supports the efficacy and safety profiles of diltiazem documented in previous well-controlled clinical trials.

Adult↗

PubMedDate not supplied

Differing roles of body mass and the renin-angiotensin system in mediating the hypertension syndrome.

BACKGROUND: Hypertension is characterized not only by a metabolic syndrome that includes obesity and insulin resistance, but also by increases in left-ventricular mass (LVM), reduced arterial compliance and altered renal function. This investigation has examined a possible role for the renin-angiotensin system as well as body mass and insulin values in mediating these cardiovascular and renal aspects of the hypertension syndrome. METHODS: This was a cross-sectional study of 142 patients identified by community screening. Mean (+/-SE) age was 46 +/- 1 years and patients had stage I-II hypertension (blood pressure: 145 +/- 1/98 +/- 0.5 mm Hg). For analysis, patients were divided into 2 groups: those with body mass index (BMI) <27 kg/m(2) (lean, n = 72) or BMI >27 kg/m(2) (overweight, n = 70). RESULTS: By univariate analysis, LVM in lean patients correlated significantly with plasma renin activity (PRA), plasma aldosterone, BMI and systolic BP; but with multivariate regression, only PRA (p < 0.01) and BMI (p < 0.04) remained in the model as independent predictors of LVM. For LVM in overweight patients, only BMI (p < 0.02) remained in the model. For total arterial compliance (stroke volume/pulse pressure) only fasting plasma insulin (in the overweight group) was significantly related (p < 0.01). For urinary protein excretion, the only predictor in lean patients was PRA (p < 0.02), whereas in overweight patients it was BMI (p < 0.03). For creatinine clearance, BMI (p < 0.01 in overweight patients) remained in the model, though by univariate regression PRA had an age-dependent dichotomous relationship to clearance: r = +0.25 (p < 0.01) in patients <55 years, but r = -0.54 (p < 0.01) in patients > or =55 years. CONCLUSION: These findings suggest that in overweight patients cardiovascular and renal values depend chiefly on body weight and insulin, but that in normal weight hypertensives the renin-angiotensin system may play the major role.

Adult↗

PubMedDate not supplied

Ambulatory blood pressure comparison of the anti-hypertensive efficacy of fixed combinations of irbesartan/hydrochlorothiazide and losartan/hydrochlorothiazide in patients with mild-to-moderate hypertension.

This study examined whether the greater anti-hypertensive efficacy of irbesartan monotherapy over losartan monotherapy extends to the respective fixed-dose combinations with hydrochlorothiazide (HCTZ) in patients with mild-to-moderate hypertension. Patients were treated with either irbesartan 150 mg/HCTZ 12.5 mg or losartan 50 mg/HCTZ 12.5 mg over a 4-week period. Twenty-four hour daytime and night-time mean blood pressure (BP), BP load and duration of action were assessed using ambulatory BP monitoring. Both treatment regimens significantly reduced BP from baseline for all efficacy variables assessed. A significant difference was noted in adjusted mean changes from baseline in 24-h ambulatory diastolic BP with irbesartan/HCTZ versus losartan/HCTZ. Reduction in diastolic load was significantly greater with irbesartan/HCTZ than with losartan/HCTZ as was mean ambulatory systolic BP during the last 4 h of the dosing interval. Both regimens were well tolerated, with no significant differences in terms of adverse event profile observed. Irbesartan 150 mg/HCTZ 12.5 mg resulted in greater reductions in ambulatory BP than losartan 50 mg/HCTZ 12.5 mg.

Adult↗

PubMedDate not supplied

The efficacy and safety of telmisartan compared to enalapril in patients with severe hypertension.

This 8-week, open-label study compared the efficacy and safety of once-daily telmisartan, either alone or in combination with hydrochlorothiazide (HCTZ) and amlodipine, with a similar enalapril regimen in patients with severe hypertension. Clinically relevant reductions in supine systolic blood pressure/DBP were observed with telmisartan (14.6/13.2 mmHg) and enalapril (13.0/12.9 mmHg) monotherapy. Incremental reductions were seen with up-titration of monotherapy (telmisartan 8.1/7.4 and enalapril 9.2/7.7 mmHg), and the addition of HCTZ (telmisartan 14.9/8.7 and enalapril 8.0/6.7 mmHg), and amlodipine (telmisartan 8.0/6.5 and enalapril 10.5/6.4). After 8 weeks of treatment, supine DBP control was achieved in 55% and 35% of the patients on the telmisartan and enalapril regimens, respectively. Both treatment regimens were well tolerated. Telmisartan, a new angiotensin receptor blocker, is a safe and effective drug to use in combination for the treatment of patients with severe hypertension and proved at least as effective as the enalapril combination.

Amlodipine↗

PubMedDate not supplied

Why lowering blood pressure is not enough: the hypertension syndrome and the clinical context of cardiovascular risk reduction.

Although drug treatment for hypertension has been widely used for many years, overall control of this disease continues to be less than optimal. Hypertension treatment has had a positive impact on stroke rates, but rates of coronary heart disease remain high. One reason for this lack of success in treatment is that physicians have focused too narrowly on lowering blood pressure. Blood pressure is a critical element of hypertension, but many other interrelated risk factors contribute to form a complex syndrome of hypertension. Studies show that young adult subjects who do not yet have high blood pressure but do have a family history of hypertension exhibit increased incidence of other risk factors, such as high cholesterol, left ventricular dysfunction, reduced arterial compliance, and insulin resistance. These patients with "normotensive hypertension" share many characteristics with patients with fully developed hypertension, both uncontrolled and controlled. The link between these many risk factors and high blood pressure seems to lie in endothelial cell balance. If this balance is upset, elements of the hypertension syndrome start to become manifest, often before blood pressure becomes elevated. Angiotensin-converting enzyme inhibitors can restore this critical balance, improving overall arterial health and arterial compliance and thus preventing the progression of the hypertension syndrome to high blood pressure and, ultimately, target organ damage.

Adult↗