National Intervention Cooperative Study in Elderly Hypertensives - NICS-EH

Description:

National Intervention Cooperative Study in Elderly Hypertensives (NICS-EH) was a multicenter, randomized, double-blind comparative study that compared the calcium channel blocker (CCB) nicardipine with the diuretic trichlormethiazide in elderly patients with hypertension.

Hypothesis:

Nicardipine and trichlormethiazide will be associated with a similar incidence of cardiovascular complications.

Study Design

Study Design:

Patients Enrolled: 429
Mean Follow Up: Up to five years
Mean Patient Age: Average 69.8 years
Female: 67

Patient Populations:

Aged ≥60 years, with mild or moderate hypertension

Exclusions:

Secondary hypertension

Primary Endpoints:

Cardiovascular complications

Secondary Endpoints:

Noncardiovascular complications

Drug/Procedures Used:

Outpatients aged ≥60 years with mild or moderate hypetension were enrolled in the study. Following a four-week placebo washout period, those with systolic blood pressure ≥160 mm Hg and <220 mm Hg, and diastolic pressure <115 mm Hg were included. Subjects were then randomly allocated to receive either nicardipine 20 mg twice daily, or trichlormethiazide 2 mg once daily. Doubling of the dose was permitted at the discretion of the investigator, if the blood pressure response was judged to be inadequate. All other antihypertensive medications were prohibited.

A "double-dummy" method was followed. Patients were followed for up to five years. Major endpoints were cardiovascular complications, such as stroke, myocardial infarction or angina, heart failure, arrhythmia, and others.

Principal Findings:

Data from a total of 414 patients were analyzed (204 in the nicardipine group; 210 in the diuretic group). Isolated systolic hypertension was present in 25% of the patients. Mean systolic and diastolic blood pressures at the time of enrollment were 172 mm Hg and 94 mm Hg, respectively, in the nicardipine group, and 173 mm Hg and 93 mm Hg, respectively, in the diuretic group.

Average blood pressures decreased substantially at the interim four-week follow-up. From 24 weeks onward, the blood pressure stabilized at 147-150/79-83 mm Hg in both groups. At 240 weeks, blood pressure was 147 ± 15/81 ± 8 mm Hg in the nicardipine group, and 147 ± 16/79 ± 9 mm Hg in the diuretic group, a significant reduction in both groups (p<0.001).

Cardiovascular complications over the course of the follow-up period occurred in 10.3% of patients in the nicardipine group and 8.6% of patients in the diuretic group (p=0.932). Using a proportional hazards model, sex- and age-adjusted risk ratio in the nicardipine group was 0.973 compared with the diuretic group (p=0.932).

Major side effects were uncommon (a total of 15 patients in the study), and minor side effects were not significantly different between the treatment groups (17% in the nicardipine group vs. 18% in the diuretic group, p=0.897).

Interpretation:

Among elderly patients with mild to moderate hypertension, treatment with a dihydropyridine-class calcium channel antagonist was associated with a similar rate of cardiovascular complications compared with a thiazide-type diuretic. The NICS-EH study was the first to directly compare a CCB to a diuretic in treatment of hypertension.

The trial was small, and recruited an insufficient number of patients to analyze individual outcomes, such as heart failure, myocardial infarction, or stroke. Subsequently, a much larger, more comprehensive ALLHAT trial showed no difference between amlodipine (a CCB) and chlorthalidone (a thiazide-type diuretic) in the primary outcome of fatal coronary heart disease or nonfatal myocardial infarction.

References:

Randomized double-blind comparison of a calcium antagonist and a diuretic in elderly hypertensives. National Intervention Cooperative Study in Elderly Hypertensives Study Group. Hypertension 1999;34:1129-33.

Clinical Topics: Heart Failure and Cardiomyopathies, Prevention, Statins, Acute Heart Failure, Hypertension

Keywords: Odds Ratio, Dihydropyridines, Myocardial Infarction, Stroke, Follow-Up Studies, Chlorthalidone, Diuretics, Nicardipine, Coronary Disease, Calcium Channel Blockers, Proportional Hazards Models, Research Personnel, Heart Failure, Amlodipine, Hypertension, Trichlormethiazide


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