Jackson T. Wright, Jr., MD, PhD
Vice Chair, ALLHAT Steering Committee
Professor of Medicine
Case Western Reserve University
Director, Clinical Hypertension Program
University Hospitals of Cleveland and
the Louis Stokes Cleveland Veterans Affairs Medical Center
December 17, 2002
Press Conference Remarks
Release of the Results of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial: Findings of the Hypertension Study
Good morning. It is my privilege to share with you the ALLHAT hypertension study results. As you know, the ALLHAT study compared the thiazide-type diuretic, chlorthalidone, to three other classes of drugs. Previously we have reported that chlorthalidone was more effective than doxazosin, an alpha-adrenergic blocker. Today, we are announcing that chlorthalidone was unsurpassed by other drugs studied in blood pressure lowering, in extent of side effects, and most importantly, in the prevention of hypertension-related complications.
First, I'd like to report on the effects of these drugs on blood pressure lowering. Our analysis revealed that after 5 years of followup, participants taking lisinopril, an ACE inhibitor, had a 2 mm Hg higher systolic blood pressure and a similar diastolic blood pressure compared to those taking chlorthalidone. The difference in blood pressure lowering was smaller between those receiving amlodipine and chlorthalidone. Participants on amlodipine, a calcium channel blocker, had a 1 mm Hg higher systolic blood pressure compared to those on chlorthalidone. However, the amlodipine group had a 1 mm Hg lower diastolic blood pressure.
Now let's take a look at complications related to hypertension. There was no significant difference among treatment groups in the rates of fatal coronary heart disease and non-fatal heart attacks, both designated as primary outcomes. In addition, there was no difference in overall deaths among the groups.
All three classes of drugs reported on in the December 18 issue of JAMA--diuretics, calcium channel blockers, and ACE inhibitors--have been previously shown to lower blood pressure and reduce cardiovascular complications. In head-to-head comparisons, the diuretics were shown to be superior in treating high blood pressure and preventing cardiovascular events.
For example, compared to participants taking chlorthalidone, participants taking amlodipine had a 38 percent higher risk of heart failure and a 35 percent higher risk of being hospitalized for this condition. There was no difference in overall cardiovascular events between these two groups.
Similarly, compared to participants taking chlorthalidone, participants taking lisinopril had a 10 percent higher risk of overall cardiovascular events, including a 15 percent higher risk of stroke and a 19 percent higher risk of heart failure, an 11 percent higher risk of angina, and a 10 percent higher risk of "revascularization" procedures such as balloon angioplasty.
The results were similar for all patients regardless of sex, age category (over or under age 65), presence or absence of coronary heart disease, and the presence or absence of diabetes. The findings were consistent across a large and very diverse patient population in a variety of practice settings. The study population of over 42,000 participants was well represented by women, minorities, diabetics, and older hypertensive patients. Therefore, I can confidently say that these results should apply to almost every patient with hypertension.
ALLHAT, which had over 15,000 Black participants, was the first study to test the effectiveness of ACE inhibitors and calcium channel blockers in preventing the cardiovascular complications of hypertension in Black hypertensive patients. The amlodipine versus chlorthalidone results in Black hypertensive patients were similar to the results for these drugs in other ethnic groups. However, the differences between the lisinopril and chlorthalidone groups were greater in Black ALLHAT participants. Compared to Black participants taking chlorthalidone, Black participants on lisinopril had a 4 mm Hg higher systolic blood pressure, a 19% higher risk of all cardiovascular events, including 40% higher risk of stroke, and a 32% greater risk of heart failure. It is uncertain how much the blood pressure difference accounted for the difference in outcomes.
Finally, patients on chlorthalidone stayed on their treatment. After 5 years of follow-up, 81 percent of participants randomly assigned to chlorthalidone or amlodipine remained on the blinded drug or drug of the same class and 73 percent of patients assigned to lisinopril were still taking an ACE inhibitor.
In conclusion, the ALLHAT results indicate that thiazide-type diuretics should be considered first for drug therapy in patients with hypertension. They are unsurpassed at lowering blood pressure and reducing clinical complications of hypertension. Furthermore, they are well tolerated by patients and they cost less.