Left atrial systolic force in hypertensive patients with left ventricular hypertrophy predicts atrial fibrillation

Background

Recently increased left atrial systolic force (LASF), a measure of left atrial function, has been associated with left ventricular hypertrophy (LVH) in hypertensive patients. Impaired left ventricular relaxation is often seen in hypertensive patients and because of the correlated left ventricular filling impairment the atrial contribution to ventricular filling is important. LASF may increase as a compensatory response to preserve a sufficient stroke volume, which partly could explain the association between age-related prolonged left ventricular relaxation and increased LASF. Reduced left atrial function has also been shown to be associated with poor prognosis in patients with atrial fibrillation. It remains unknown whether LASF can be used as a predictor of new-onset atrial fibrillation (NOAF). Furthermore, the influence of treatment with atenolol and losartan on LASF is unclear.

Purpose

We aimed to determine whether LASF correlates to incident atrial fibrillation and whether the preservation of LASF reduces the risk of new onset atrial fibrillation (NOAF).

Methods

N=758 patients without atrial fibrillation at baseline were enrolled from the Losartan Intervention For Endpoint reduction in hypertension (LIFE) echocardiography sub study. Participants of the LIFE-study were randomized to either atenolol- or losartan-based treatment. Mean follow-up was 59 month. LASF was calculated using average mitral orifice area and mitral peak A velocity obtained by Doppler echocardiography.

Results

At baseline 25% of patients had a LASF≤10.3kdyn. Compared to other quartiles this quartile had a higher proportion of men, lower heart rate, body mass index and age. After controlling for these variables patients in the first quartile had lower stroke volume compared to other quartiles. New-onset AF occurred in 29 (8.1/1,000 patients-years of follow-up) patients. In multivariable Cox regression analyses with backwards elimination increasing LASF was associated with lower risk of NOAF (HR=0.90 [95% confidence interval 0.85–0.96], p=0.001). Integrated discrimination improvement was 0.054 (p=0.004) and there was a borderline significant net reclassification improvement of 19.2% (p=0.075). Over time LASF decreased more in the atenolol-based than the losartan-based treatment group (p<0.001).

Conclusions

Low left atrial systolic force (LASF) was associated with higher risk of NOAF. Losartan-based treatment was associated with better preservation of LASF compared to atenolol-based treatment. Our data thus suggest that hypertensive patients with LVH and low LASF identifies a patient group with progressed left atrial dysfunction and with high risk of NOAF. Because of the preserving effect of losartan on the function and structure of the left atrium, treating hypertensive patients with LVH with losartan might decrease their risk of incident atrial fibrillation.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The LIFE study originally received support from Merck & Co., Inc.

Incident atrial fibrillation and heart failure in treated hypertensive patients with left ventricular hypertrophy

Background

Hypertension and left ventricular hypertrophy (LVH) are predictors of atrial fibrillation (AF) and heart failure (HF). The incidence rates of AF and HF and especially the combination of these two complications in hypertensive patients with LVH receiving antihypertensive treatment are unknown, and so are the association with risk levels of other cardiovascular diseases and death in hypertensive patients with LVH who develop new onset AF and HF.

Purpose

We aimed to investigate the appearance and severity of AF and HF in 8,702 hypertensive patients aged 55–80 years with LVH receiving antihypertensive treatment in a prospective and randomized clinical trial primarily designed to investigate the preventive effect on a composite endpoint of myocardial infarction, stroke and cardiovascular death.

Methods

Included were patients who had sinus rhythm in ECG and no history of AF or HF when they were randomly allocated to blinded study medication with losartan or atenolol. Additional medication was given with hydrochlorothiazide and calcium antagonist if needed to gain blood pressure control. Incident AF was detected by annual ECGs and from adverse event reports submitted by the 930 clinical investigators. Incident HF was diagnosed according to Framingham criteria. Endpoints including incident HF, myocardial infarction, stroke and cardiovascular death were reported with relevant documentation by the investigators, and adjudicated by an expert endpoint committee.

Results

Incident AF occurred in 679 patients (7.8%) and HF in 246 patients (2.8%) during 4.7±1.1 years mean follow-up. Incident AF was associated with a >4-fold increased risk of developing subsequent HF (HR=4.7; 95% CIs, 3.1–7.0; P<0.001) in multivariable Cox analyses adjusting for age, sex, race, randomized treatment, standard cardiovascular risk factors and incident myocardial infarction. The development of HF as a time-dependent variable was associated with a multivariable-adjusted 3-fold increase of the primary study endpoint (HR=3.11; 95% CIs, 1.52 to 6.39; P<0.001) which was the composite of myocardial infarction, stroke or cardiovascular death.

Incident HF was associated with a >3-fold increased risk of developing subsequent AF (HR=3.3; 95% CIs, 2.3–4.9; P<0.001). This development of AF was associated with more than a 2-fold increase of the composite of myocardial infarction, stroke or cardiovascular death in multivariable Cox analysis (HR=2.26; 95% CIs, 1.09–4.67; P=0.028).

Conclusions

Incident atrial fibrillation and heart failure are associated with increased risk of the other in treated hypertensive patients with left ventricular hypertrophy. These hypertensive patients who subsequently develop both atrial fibrillation and heart failure during antihypertensive treatment have particularly high risk of an additional composite endpoint consisting of myocardial infarction, stroke or cardiovascular death.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): The study originally received support from Merck & Co., Inc.

Health-care costs of losartan and candesartan in the primary treatment of hypertension

A recent study of two widely used angiotensin receptor blockers reported a reduced risk of cardiovascular events (−14.4%) when using candesartan compared with losartan in the primary treatment of hypertension. In addition to clinical benefits, costs associated with treatment strategies must be considered when allocating scarce health-care resources. The aim of this study was to assess resource use and costs of losartan and candesartan in hypertensive patients. Resource use (drugs, outpatient contacts, hospitalizations and laboratory tests) associated with losartan and candesartan treatment was estimated in 14 100 patients in a real-life clinical setting. We electronically extracted patient data from primary care records and mandatory Swedish national registers for death and hospitalization. Patients treated with losartan had more outpatient contacts (+15.6%), laboratory tests (+13.8%) and hospitalizations (+13.8%) compared with the candesartan group. During a maximum observation time of 9 years, the mean total costs per patient were 10 369 Swedish kronor (95% confidence interval: 3109–17 629) higher in the losartan group. In conclusion, prescribing candesartan for the primary treatment of hypertension results in lower long-term health-care costs compared with losartan.

Changes in the lipoprotein profile during antihypertensive therapy

In the Oslo study serum lipids have been studied during treatment with some of the most frequently used antihypertensive drugs. Hydrochlorothiazide induced no significant changes. However, those patients with the most marked increase in uric acid showed an increase of serum triglycerides. Total cholesterol was unchanged in these men. The beta-adrenoceptorblocking drugs propranolol, atenolol and oxprenolol caused a reduction of HDL cholesterol and an increase of total triglycerides. Total cholesterol remained unchanged. Pindolol induced no significant lipoprotein changes. Prazosin reduced total cholesterol and total triglycerides. HDL cholesterol remained unchanged. LDL + VLDL cholesterol was reduced.

Achieving blood pressure goals globally: five core actions for health-care professionals. A worldwide call to action

The prevalence of hypertension continues to rise across the world, and most patients who receive medical intervention are not adequately treated to goal. A Working Group including representatives of nine international health-care organizations was convened to review the barriers to more effective blood pressure control and propose actions to address them. The group concluded that tackling the global challenge of hypertension will require partnerships among multiple constituencies, including patients, health-care professionals, industry, media, health-care educators, health planners and governments. Additionally, health-care professionals will need to act locally with renewed impetus to improve blood pressure goal rates. The Working Group identified five core actions, which should be rigorously implemented by practitioners and targeted by health systems throughout the world: (1) detect and prevent high blood pressure; (2) assess total cardiovascular risk; (3) form an active partnership with the patient; (4) treat hypertension to goal and (5) create a supportive environment. These actions should be pursued with vigour in accordance with current clinical guidelines, with the details of implementation adapted to the economic and cultural setting.

ESH-ESC Guidelines for the Management of Hypertension

The following is a brief statement of the 2003 European Society of Hypertension (ESH)-European Society of Cardiology (ESC) guidelines for the management of arterial hypertension. The continuous relationship between the level of blood pressure and cardiovascular risk makes the definition of hypertension arbitrary. Since risk factors cluster in hypertensive individuals, risk stratification should be made and decision about the management should not be based on blood pressure alone, but also according to the presence or absence of other risk factors, target organ damage, diabetes, and cardiovascular or renal damage, as well as on other aspects of the patient's personal, medical and social situation. Blood pressure values measured in the doctor's office or the clinic should commonly be used as reference. Ambulatory blood pressure monitoring may have clinical value, when considerable variability of office blood pressure is found over the same or different visits, high office blood pressure is measured in subjects otherwise at low global cardiovascular risk, there is marked discrepancy between blood pressure values measured in the office and at home, resistance to drug treatment is suspected, or research is involved. Secondary hypertension should always be investigated. The primary goal of treatment of patient with high blood pressure is to achieve the maximum reduction in long-term total risk of cardiovascular morbidity and mortality. This requires treatment of all the reversible factors identified, including smoking, dislipidemia, or diabetes, and the appropriate management of associated clinical conditions, as well as treatment of the raised blood pressure per se. On the basis of current evidence from trials, it can be recommended that blood pressure, both systolic and diastolic, be intensively lowered at least below 140/90 mmHg and to definitely lower values, if tolerated, in all hypertensive patients, and below 130/80 mmHg in diabetics. Lifestyle measures should be instituted whenever appropriate in all patients, including subjects with high normal blood pressure and patients who require drug treatment. The purpose is to lower blood pressure and to control other risk factors and clinical conditions present. In most, if not all, hypertensive patients, therapy should be started gradually, and target blood pressure achieved progressively through several weeks. To reach target blood pressure, it is likely that a large proportion of patients will require combination therapy with more than one agent. The main benefits of antihypertensive therapy are due to lowering of blood pressure per se. There is also evidence that specific drug classes may differ in some effect or in special groups of patients. The choice of drugs will be influenced by many factors, including previous experience of the patient with antihypertensive agents, cost of drugs, risk profile, presence or absence of target organ damage, clinical cardiovascular or renal disease or diabetes, patient's preference.

Effects of individual risk factors on the incidence of cardiovascular events in the treated hypertensive patients of the Hypertension Optimal Treatment Study. HOT Study Group

BACKGROUND

The Hypertension Optimal Treatment (HOT) Study has provided information about cardiovascular events in 18790 hypertensives, subjected to pronounced blood pressure (BP) lowering for a mean of 3.8 years. The HOT study data have subsequently been analysed after stratification of the patients according to global cardiovascular risk, and it has been found that, despite intensive blood pressure lowering in all risk strata, morbid event rates increased with increasing risk stratum.

OBJECTIVES

Previously analysed global risk strata were based on combinations of risk factors. The analyses presented here were intended to provide information on the relative role that the presence of each individual factor may have in increasing cardiovascular risk, despite good BP control.

METHODS

Risk ratios (RR) for patients with and those without a risk factor were calculated with 95% confidence intervals (CI) using a Cox proportional hazard model, and adjusted for all variables except the one under examination.

RESULTS

For all risk factors considered and for all types of event, RR were always greater than 1, indicating a greater risk in the presence, compared with that in the absence of each factor. The male gender was a statistically significant risk for cardiovascular (CV) events, CV and total mortality and particularly for myocardial infarction (MI); age > or = 65 years for CV events, stroke, CV and particularly total mortality; smoking for all events analysed, but particularly for total mortality (twice higher in smokers than in non-smokers); high serum cholesterol (> 6.8 mmol/l) for CV events, MI and CV mortality; high serum creatinine (> 155 micromol/l) for CV events, stroke, CV and total mortality; diabetes for CV events, stroke, total mortality and particularly CV mortality; and ischaemic heart disease for all events analysed. Adjusted RR were often close to or greater than 2.

CONCLUSIONS

Each of the risk factors considered was found to be an important cause of residual risk, despite good BP control. These findings emphasize the importance of addressing other correctable risk factors, e.g. smoking, hypercholesterolaemia and diabetes, as well as rigorous control of blood pressure, and of initiating antihypertensive therapy before cardiovascular and renal damage becomes manifest.

Self-measurement of blood pressure in clinical trials and therapeutic applications

Self-measurement of blood pressure (SMBP) is increasingly used to assess blood pressure outside the medical setting. A prerequisite for the wide use of SMBP is the availability of validated devices providing reliable readings when they are handled by patients. This is the case today with a number of fully automated oscillometric apparatuses. A major advantage of SMBP is the great number of readings, which is linked with high reproducibility. Given these advantages, one of the major indications for SMBP is the need for evaluation of antihypertensive treatment, either for individual patients in everyday practice or in clinical trials intended to characterize the effects of blood-pressure-lowering medications. In fact, SMBP is particularly helpful for evaluating resistant hypertension and detecting white-coat effect in patients exhibiting high office blood pressure under antihypertensive therapy. SMBP might also motivate the patient and improve his or her adherence to long-term treatment. Moreover, SMBP can be used as a sensitive technique for evaluating the effect of antihypertensive drugs in clinical trials; it increases the power of comparative trials, allowing one to study fewer patients or to detect smaller differences in blood pressure than would be possible with the office measurement. Therefore, SMBP can be regarded as a valuable technique for the follow-up of treated patients as well as for the assessment of antihypertensive drugs in clinical trials.

The Losartan Intervention For Endpoint reduction (LIFE) in Hypertension study: rationale, design, and methods. The LIFE Study Group

The treatment of hypertension mainly with diuretics and beta blockers reduces cardiovascular mortality and morbidity, largely due to a decreased incidence of stroke, whereas the beneficial effects of antihypertensive therapy on the occurrence of coronary events have been less than expected from epidemiological studies. Furthermore, treated hypertensive patients still have a higher cardiovascular complication rate, compared with matched normotensives. This is particularly evident in patients with left ventricular hypertrophy (LVH), a major independent risk indicator for cardiovascular disease. In addition to elevating blood pressure, angiotensin II (A-II) exerts an important influence on cardiac structure and function, stimulating cell proliferation and growth. Thus, to further reduce morbidity and mortality when treating hypertensive patients, it may be important to effectively block the effects of A-II. This can be achieved directly at the A-II receptor level by losartan, the first of a new class of antihypertensive agents. It therefore seems pertinent to investigate whether selective A-II receptor blockade with losartan not only lowers blood pressure but also reduces LVH more effectively than current therapy, and thus improves prognosis. The Losartan Intervention For Endpoint reduction (LIFE) in Hypertension study is a double-blind, prospective, parallel group study designed to compare the effects of losartan with those of the beta-blocker atenolol on the reduction of cardiovascular morbidity and mortality in approximately 8,300 hypertensive patients (initial sitting diastolic blood pressure 95 to 115 mm Hg or systolic blood pressure 160 to 200 mm Hg) with electrocardiographically documented LVH. The study, which will continue for at least 4 years and until 1,040 patients experience one primary endpoint, has been designed with a statistical power that will detect a difference of at least 15% between groups in the incidence of combined cardiovascular morbidity and mortality. It is also the first prospective study with adequate power to link reversal of LVH to reduction in major cardiovascular events. The rationale of the study, which will involve more than 800 clinical centers in Scandinavia, the United Kingdom, and the United States, is discussed, and the major features of its design and general organization are described. On April 30, 1997, when inclusion was stopped, 9,218 patients had been randomized.

[Home blood pressure measurement in general practice patients]

In 68 consecutive patients with mild hypertension, blood pressure was measured by general practitioners during visits to the clinic, by nurse and by the patients at home. Mean age was 50 years (SD: 11) for both genders and 60% were women. Blood pressure and heart rate were significantly higher when measured by physicians than by nurse and patient (p < 0.01). During the study period of six weeks a significant decrease in blood pressures was registered by both physicians and patients. The study demonstrates the feasibility of home blood pressure monitoring as a part of the practice to diagnose hypertension in general practice.

Effect of angiotensin II receptor blockade on fibrinolysis during acute hyperinsulinemia in patients with essential hypertension

We performed the present study to investigate indirectly the in vivo effects of angiotensin II on fibrinolysis and catecholamines by treatment with losartan, a selective angiotensin II type 1 receptor antagonist. The effects were evaluated in basal conditions as well as in two different models of acute hyperinsulinemia physiologically induced by oral glucose ingestion and by a euglycemic glucose clamp technique. Twenty subjects with moderate hypertension were included in a randomized, double-blind, placebo-controlled crossover study of 4-week treatment periods. Plasma levels of catecholamines, tissue plasminogen activator activity and antigen, and plasminogen activator inhibitor type 1 activity and antigen were unchanged in the basal state after 4 weeks of treatment. During both models of hyperinsulinemia, plasminogen activator inhibitor activity and antigen decreased significantly (both P<.001), and tissue plasminogen activator activity increased significantly (P<.Ol). Norepinephrine did not change during any of the procedures, whereas epinephrine increased significantly after 3 hours of the oral glucose tolerance test. Changes from baseline did not differ between the treatment and placebo regimens during the hyperinsulinemic procedures with regard to either of the fibrinolytic variables or the catecholamines. In conclusion, we could not demonstrate any effects of 4 weeks of treatment with losartan on plasma levels of fibrinolytic variables or catecholamines either in basal conditions or during acute hyperinsulinemia. However, the present findings do not preclude more direct effects of angiotensin II or involvement of other receptor subtypes on fibrinolysis.