Impact of therapy initiation with amlodipine or losartan on hemodynamic endpoints and JNC-VI blood pressure stage.

The relative efficacy of long-acting calcium channel antagonists and angiotensin II receptor blocking agents has been described in clinical trials; however, their effectiveness in an actual practice setting has not been well studied. This study assessed the effectiveness of 2 commonly prescribed antihypertensives, amlodipine and losartan, either as monotherapy or as add-on for patients insufficiently controlled on beta-blocker or diuretic therapy. This was a retrospective, observational study that utilized electronic medical records. Hypertensive patients more than 40 years old who were new users of amlodipine or losartan were included in the study. Patients with congestive heart failure or those using antihypertensives other than diuretics or beta-blockers were excluded. Blood pressure (BP) readings were followed up to 6 months after enrollment. Univariate and multivariate regression models were used to assess the impact of amlodipine or losartan therapy on hemodynamic end points and on JNC-VI BP stage. A total of 346 patients met the entry criteria. Of these, 275 (79.5%) amlodipine and 71 (20.5%) were prescribed losartan. Mean changes in systolic and diastolic blood pressure were greater for patients receiving amlodipine in univariate and multivariate analyses (reduction of 20/8 and 11/4 mm Hg, respectively; P<0.05). Mean change in pulse pressure trended strongly in favor of amlodipine (11.8 mm Hg vs. 7 mm Hg, P = 0.08). Univariate analysis indicated that amlodipine-treated patients were more likely to move to a better JNC-VI BP stage, where as losartan-treated patients, on average, moved to a worse stage. Amlodipine therapy was superior to losartan therapy among this population of hypertensive patients.

Cardiovascular disease costs associated with uncontrolled hypertension.

This research evaluated the effect of inadequate blood pressure (BP) control on selected cardiovascular (CV) disease outcomes and costs for American patients with hypertension. The results of a hypertension outcomes trial, which provided incidence rates for CV disease morbidity and mortality at distinct systolic/diastolic BP ranges, were integrated with U.S. hypertension statistics from the Third National Health and Nutrition Examination Survey and cost estimates for stroke, congestive heart failure, and myocardial infarction. A model was developed to estimate the number of cases and costs of myocardial infarction, stroke, and congestive heart failure for patients achieving BP control versus those not achieving control. For the U.S. population with hypertension, inadequate BP control was estimated to result in 39,702 CV events, 8,374 CV disease deaths, and $964 million in direct medical expenditures. Within the medicated population with CV disease, the incremental costs of failure to attain BP goals reached approximately $467 million. These results reflect the importance of adequate BP control--in particular, systolic BP control--in reducing cardiovascular morbidity, mortality, and overall health care expenditures among patients with hypertension.

Economic benefits of amlodipine treatment in patients with coronary artery disease.

OBJECTIVE: To estimate the potential savings in overall cardiovascular disease (CVD) treatment costs for the US population with coronary artery disease (CAD) resulting from the use of amlodipine. STUDY DESIGN AND METHODS: Using patient-level data from a retrospective analysis of the Prospective Evaluation of the Vascular Effects of Norvasc Trial (PREVENT), a randomised, placebo-controlled clinical trial (n = 825), we constructed a Markov cohort simulation model to estimate the health economic outcomes of patients with CAD treated with either amlodipine or placebo. PERSPECTIVE: Healthcare payer perspective. RESULTS: The expected number of CVD events for amlodipine recipients was significantly lower than the number of CVD events in the placebo cohort (p < 0.01). The net present value of the cost per patient for CVD treatment was estimated to be $US14 117 for amlodipine recipients and $US16 683 (1999 values, assuming a 3% discount rate) for placebo recipients over 3 years of follow-up with cost savings realised in the amlodipine cohorts after 6 months. CONCLUSIONS: According to the model, amlodipine results in an expected per patient cost savings of $US2566 over a 3-year period, mainly due to a reduction in hospitalisations for cardiovascular-related events and procedures.

A retrospective electronic chart review of blood pressure changes in elderly patients treated with amlodipine or an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker.

BACKGROUND: Despite the high costs of managing hypertension, pharmacologic intervention is cost-effective, particularly in patients at highest risk for cardiovascular events. The prevalence of hypertension in the elderly and the age-associated risks of coronary artery disease and stroke suggest that early identification and aggressive treatment should be priorities in this population. OBJECTIVE: The aim of this study was to compare the effect of amlodipine and angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) in the treatment of essential hypertension in elderly patients (>60 years) in an actual practice setting. METHODS: This was a retrospective cohort analysis using electronic medical records stored in the Physicians Data Corporation cardiology database. Patients aged >60 years who received care from a cardiologist and who had a recorded diagnosis of hypertension during 1997 or 1998 were identified. For inclusion, patients had to have received an initial prescription for amlodipine, an ACE inhibitor, or an ARB at the index visit. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) readings from the index visit and > or =1 subsequent visit (<180 days after the index visit) were assessed. RESULTS: A total of 192 patients (56.3% male; mean age, 71.9 years) met the inclusion criteria. Amlodipine-treated patients experienced a mean decrease in SBP of 26.7 mm Hg, compared with 18.8 mm Hg in patients receiving an ARB and 15.8 mm Hg for patients receiving an ACE inhibitor (P = 0.008, amlodipine vs ACE inhibitor). DBP decreased 8.8 mm Hg with amlodipine, 8.7 mm Hg with an ARB, and 6.2 mm Hg with an ACE inhibitor. After adjusting for age, sex, and disease severity, amlodipine-treated patients were -4 times as likely to move to a better blood pressure stage than patients treated with an ARB or an ACE inhibitor (odds ratio, ARB vs amlodipine: 0.245; 95% CI, 0.080-0.753; odds ratio, ACE inhibitor vs amlodipine: 0.234; 95% CI, 0.072-0.761). CONCLUSION: Results of this study indicate that in patients aged >60 years, amlodipine may be an effective therapy for hypertension.

Exploring the methodological challenges of investigating comparison groups with different underlying characteristics: a case study.

OBJECTIVE: To examine challenges in forming accurate conclusions from claims data when comparing different patient groups, and to stress the need to adjust for confounding variables through application of statistical methods. METHODS: Patients who were 60 or older and began amlodipine or felodipine in 1997 or 1998 were identified from a proprietary managed care claims database. Patients had 6 months of medical and outpatient pharmacy benefits coverage before and after initiating therapy. They were stratified on varying degrees of hypertension severity and on all-condition clinical complexity, and quantified with a proprietary Burden of Illness (BOI) score, defined as the expected resource use for the patient.s combined conditions during the 6 months before therapy. RESULTS: Of the 17,667 patients, 10,469 (59.3%) were female. The 12,389 amlodipine users were similar in age to felodipine users (n=5,278), 73 versus 74, respectively. More amlodipine users were assigned to the 2 most clinically complex quintiles of the BOI distribution (45.5% to 26.9%), with 24.3% of patients in the top quintile (9.7% for felodipine) and twice the prevalence of ischemic heart disease/angina (42.4% versus 19.4%). High-severity hypertension was found among 33.6% of amlodipine users, contrasted with 17.9% for felodipine. A significant difference in the mean average daily dose (ADD) between the amlodipine (5.93 mg) and felodipine (5.8 mg) groups (P=0.0007) was noted. CONCLUSION: These results stress the importance of assessing the impact of potentially confounding variables and the need to address differing patient characteristics through either risk adjustment or stratification in making head-to-head comparisons.