Cost-effectiveness of antihypertensive treatment in patients 80 years of age or older in Switzerland: an analysis of the HYVET study from a Swiss perspective.

This analysis shows the economic benefit of antihypertensive treatment in patients 80 years of age or older from the perspective of the Swiss healthcare system. The cost-effectiveness analysis of antihypertensive treatment in the elderly was carried out applying the results of the Hypertension in the Very Elderly Trial study to the Swiss healthcare system. The analysis shows that hypertension treatment provides, compared with placebo, an additional life expectancy of 0.0457 years per patient, over a follow-up period of 2 years. The medication cost was covered by the reduction of costs related to the treatment of strokes, myocardial infarctions and heart failure: the total cost per patient in the active group resulted in a dominant strategy of savings compared with the placebo group. Sensitivity analysis yielded a stable estimate after varying the costs of medication, stroke, myocardial infarction, heart failure and life expectancy, confirming the robustness of these results. Moreover, considering that antihypertensive treatment also positively affects the incidence of dementia, those net benefits might even be underestimated.

Task force IV: Clinical use of ambulatory blood pressure monitoring. Participants of the 1999 Consensus Conference on Ambulatory Blood Pressure Monitoring.

OBJECTIVE: To reach a consensus on the clinical use of ambulatory blood pressure monitoring (ABPM). METHODS: A task force on the clinical use of ABPM wrote this overview in preparation for the Seventh International Consensus Conference (23-25 September 1999, Leuven, Belgium). This article was amended to account for opinions aired at the conference and to reflect the common ground reached in the discussions. POINTS OF CONSENSUS: The Riva Rocci/Korotkoff technique, although it is prone to error, is easy and cheap to perform and remains worldwide the standard procedure for measuring blood pressure. ABPM should be performed only with properly validated devices as an accessory to conventional measurement of blood pressure. Ambulatory recording of blood pressure requires considerable investment in equipment and training and its use for screening purposes cannot be recommended. ABPM is most useful for identifying patients with white-coat hypertension (WCH), also known as isolated clinic hypertension, which is arbitrarily defined as a clinic blood pressure of more than 140 mmHg systolic or 90 mmHg diastolic in a patient with daytime ambulatory blood pressure below 135 mmHg systolic and 85 mmHg diastolic. Some experts consider a daytime blood pressure below 130 mmHg systolic and 80 mmHg diastolic optimal. Whether WCH predisposes subjects to sustained hypertension remains debated. However, outcome is better correlated to the ambulatory blood pressure than it is to the conventional blood pressure. Antihypertensive drugs lower the clinic blood pressure in patients with WCH but not the ambulatory blood pressure, and also do not improve prognosis. Nevertheless, WCH should not be left unattended. If no previous cardiovascular complications are present, treatment could be limited to follow-up and hygienic measures, which should also account for risk factors other than hypertension. ABPM is superior to conventional measurement of blood pressure not only for selecting patients for antihypertensive drug treatment but also for assessing the effects both of non-pharmacological and of pharmacological therapy. The ambulatory blood pressure should be reduced by treatment to below the thresholds applied for diagnosing sustained hypertension. ABPM makes the diagnosis and treatment of nocturnal hypertension possible and is especially indicated for patients with borderline hypertension, the elderly, pregnant women, patients with treatment-resistant hypertension and patients with symptoms suggestive of hypotension. In centres with sufficient financial resources, ABPM could become part of the routine assessment of patients with clinic hypertension. For patients with WCH, it should be repeated at annual or 6-monthly intervals. Variation of blood pressure throughout the day can be monitored only by ABPM, but several advantages of the latter technique can also be obtained by self-measurement of blood pressure, a less expensive method that is probably better suited to primary practice and use in developing countries. CONCLUSIONS: ABPM or equivalent methods for tracing the white-coat effect should become part of the routine diagnostic and therapeutic procedures applied to treated and untreated patients with elevated clinic blood pressures. Results of long-term outcome trials should better establish the advantage of further integrating ABPM as an accessory to conventional sphygmomanometry into the routine care of hypertensive patients and should provide more definite information on the long-term cost-effectiveness. Because such trials are not likely to be funded by the pharmaceutical industry, governments and health insurance companies should take responsibility in this regard.

Clinical value of ambulatory blood pressure monitoring in the assessment of antihypertensive therapy.

Non-invasive ambulatory blood pressure monitoring (ABPM) is particularly useful for assessing the efficacy of antihypertensive drugs. It provides a large number of blood pressure readings during daytime as well as night-time, which results in a more precise assessment of prevailing blood pressure than can be obtained from sporadic measurements taken by a doctor. Because of this greater precision ABPM reduces the number of patients required in clinical trials to demonstrate differences. It also allows one to define precisely the profile of the blood-pressure-lowering effect of a given drug. Placebo has little effect on ABPM. Thus, a placebo phase is not absolutely necessary. ABPM makes it possible to evaluate the efficacy of an antihypertensive medication by analysing data for patients with a placebo effect separately from data for true responders to the medication. In everyday practice ABPM helps one to detect among patients with hypertension refractory to treatment those who exhibit controlled blood pressures outside the medical environment, thus permitting one to avoid an unnecessary step-up of treatment. In addition ABPM can also help one to identify symptoms occurring during antihypertensive treatment that are related to excessive drug-induced changes in blood pressure.

[Ambulatory blood pressure monitoring in the assessment of the hypertensive patient]. / L'enregistrement tensionnel en ambulatoire dans l'évaluation du malade hypertendu.

Non-invasive ambulatory blood pressure monitoring allows to record numerous blood pressures during everyday activities. The relationship between blood pressure and target organ damage is closer with ambulatory than conventional office blood pressures. Monitoring blood pressure outside the doctor's office appears more and more useful in diagnosing and treating hypertension. This approach makes it possible to recognize high-risk hypertensive patients, i.e. patients exhibiting abnormally increased blood pressures in the presence as well as in the absence of the doctor.

Assessment of antihypertensive efficacy by non-invasive ambulatory blood pressure monitoring.

The session devoted to the usefulness of non-invasive ambulatory blood pressure monitoring (ABPM) in the evaluation of antihypertensive therapy allowed us to discuss a number of important issues. ABPM emerged as a widely accepted technique to measure blood pressure in clinical trials. Actually, it was generally considered to provide more valuable information than do conventional blood pressure readings obtained sporadically by a doctor. However, still debated was the way of analysing ABPM recordings. This was particularly true with respect to the proposal of considering separately responders and non-responders when assessing the quality of blood pressure control achieved during treatment.

Interactions between NPY and its receptor: assessment using ant-NPY antibodies.

The present data show that monoclonal antibodies (NPY02, NPY03, NPY04, NPY05) directed against 4 distinct epitopes on NPY may have different actions on NPY binding and NPY-induced cellular responses. NPY02 and NPY05 recognize the 11-24 and 32-36 amidated form of NPY, respectively. These 2 antibodies block the binding of NPY to its receptor as well as the NPY-induced inhibition of cAMP accumulation caused in SK-N-MC cells by forskolin. NPY02 and NPY05 have also an inhibitory action on NPY-induced contraction of rabbit femoral arteries. NPY03 and NPY04 are directed against the 27-34 and 1-12 part of NPY, respectively. NPY03 and NPY04 inhibit the binding of NPY only at very high concentrations and have a weak effect on cAMP response to NPY. NPY02 and NPY05 might provide useful tools to study the effect of NPY in cellular systems and organ preparations.

Blood pressure monitoring for quality assessment of antihypertensive therapy.

Despite many new therapeutic approaches to the treatment of hypertension and new diagnostic methods, the measurement of the most basic parameter, the blood pressure itself, has not changed over many years. The most commonly used method records the blood pressure on a single occasion and it is then assumed that this single reading is representative of the blood pressure of that patient at all times. This paper presents evidence, based on published studies, showing that the single "office" blood pressure reading gives little information about the blood pressure during daily activities. A study in 101 volunteers and a study in 38 patients with hypertension both showed that, not only is the "office" reading not the same as the average of many blood pressure readings made over 24 h using a Remler device, but also that the difference cannot be predicted. In some cases, the "office" pressure is higher and in some cases lower than the Remler blood pressure. This difference may explain the apparent blood pressure lowering effect of placebo. This has been frequently reported when the blood pressure is measured by the physician but ambulatory blood pressure readings have failed to show this effect. Finally, the inaccuracy of the "office" blood pressure may obscure smaller differences between two treatment groups in a clinical trial which could have been clearly demonstrated if the blood pressure had been recorded using an ambulatory method.