Chuke Nwachuku

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT): clinical center recruitment experience.

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a randomized clinical outcome trial of antihypertensive and lipid-lowering therapy in a diverse population (including substantial numbers of women and minorities) of 42,419 high-risk hypertensives aged > or = 55 years with a planned mean follow-up of 6 years. In this paper, we describe our experience in the identification, recruitment, and selection of clinical centers for this large simple trial capable of meeting the recruitment goals outlined for ALLHAT, and we highlight factors associated with clinical center performance. Over 135,000 recruitment brochures were mailed to physicians. Requests for information and application packets were received from 9351 (6.8%) interested investigators. A total of 1053 completed applications were received and 909 sites (86%) were eventually approved to join the trial. Of the approved sites, 278 either later declined participation or were never activated, and 8 were closed within a year for lack of enrollment. The final 623 randomizing centers exceeded the trials recruitment goal to enroll at least 40,000 participants into the trial, although the recruitment period was extended 1.5 years longer than planned. Fewer than a quarter of the sites (22.6%) were recruited from academic medical centers or Department of Veterans Affairs Medical Centers. More than half of the sites (54.7%) were private solo or group practices, which contributed 53% of randomized participants. Community health centers comprised about 8% of the ALLHAT sites and 2.9% were part of health maintenance organizations. More than 22% of the principal investigators reported that they had no previous clinical research experience. In summary, ALLHAT was successful in recruiting a diverse group of clinical centers to achieve its patient recruitment goals.

Clinical Events in High-Risk Hypertensive Patients Randomly Assigned to Calcium Channel Blocker Versus Angiotensin-Converting Enzyme Inhibitor in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

The Antihypertensive and Lipid-Lowering treatment to prevent Heart Attack Trial (ALLHAT) provides a unique opportunity to compare the long-term relative safety and efficacy of angiotensin-converting enzyme inhibitor and calcium channel blocker–initiated therapy in older hypertensive individuals. Patients were randomized to amlodipine (n=9048) or lisinopril (n=9054). The primary outcome was combined fatal coronary heart disease or nonfatal myocardial infarction, analyzed by intention-to-treat. Secondary outcomes included all-cause mortality, stroke, combined cardiovascular disease (CVD), end-stage renal disease (ESRD), cancer, and gastrointestinal bleeding. Mean follow-up was 4.9 years. Blood pressure control was similar in nonblacks, but not in blacks. No significant differences were found between treatment groups for the primary outcome, all-cause mortality, ESRD, or cancer. Stroke rates were higher on lisinopril in blacks (RR=1.51, 95% CI 1.22 to 1.86) but not in nonblacks (RR=1.07, 95% CI 0.89 to 1.28), and in women (RR=1.45, 95% CI 1.17 to 1.79), but not in men (RR=1.10, 95% CI 0.92 to 1.31). Rates of combined CVD were higher (RR=1.06, 95% CI 1.00 to 1.12) because of higher rates for strokes, peripheral arterial disease, and angina, which were partly offset by lower rates for heart failure (RR=0.87, 95% CI 0.78 to 0.96) on lisinopril compared with amlodipine. Gastrointestinal bleeds and angioedema were higher on lisinopril. Patients with and without baseline coronary heart disease showed similar outcome patterns. We conclude that in hypertensive patients, the risks for coronary events are similar, but for stroke, combined CVD, gastrointestinal bleeding, and angioedema are higher and for heart failure are lower for lisinopril-based compared with amlodipine-based therapy. Some, but not all, of these differences may be explained by less effective blood pressure control in the lisinopril arm.

Metabolic and Clinical Outcomes in Nondiabetic Individuals With the Metabolic Syndrome Assigned to Chlorthalidone, Amlodipine, or Lisinopril as Initial Treatment for Hypertension: A report from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT)

OBJECTIVE—Optimal initial antihypertensive drug therapy in people with the metabolic syndrome is unknown. RESEARCH DESIGN AND METHODS—We conducted a subgroup analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) to compare metabolic, cardiovascular, and renal outcomes in individuals assigned to initial hypertension treatment with a thiazide-like diuretic (chlorthalidone), a calcium channel blocker (CCB; amlodipine), or an ACE inhibitor (lisinopril) in nondiabetic individuals with or without metabolic syndrome. RESULTS—In participants with metabolic syndrome, at 4 years of follow-up, the incidence of newly diagnosed diabetes (fasting glucose ≥126 mg/dl) was 17.1% for chlorthalidone, 16.0% for amlodipine (P = 0.49, chlorthalidone vs. amlodipine) and 12.6% for lisinopril (P < 0.05, lisinopril vs. chlorthalidone). For those without metabolic syndrome, the rate of newly diagnosed diabetes was 7.7% for chlorthalidone, 4.2% for amlodipine, and 4.7% for lisinopril (P < 0.05 for both comparisons). There were no differences in relative risks (RRs) for outcomes with amlodipine compared with chlorthalidone in those with metabolic syndrome; in those without metabolic syndrome, there was a higher risk for heart failure (RR 1.55 [95% CI 1.25–1.35]). In comparison with lisinopril, chlorthalidone was superior in those with metabolic syndrome with respect to heart failure (1.31 [1.04–1.64]) and combined cardiovascular disease (CVD) (1.19 [1.07–1.32]). No significant treatment group–metabolic syndrome interaction was noted. CONCLUSIONS—Despite a less favorable metabolic profile, thiazide-like diuretic initial therapy for hypertension offers similar, and in some instances possibly superior, CVD outcomes in older hypertensive adults with metabolic syndrome, as compared with treatment with CCBs and ACE inhibitors.

Metabolic and Clinical Outcomes in Non-Diabetic Individuals with the Metabolic Syndrome Assigned to Chlorthalidone, Amlodipine, or Lisinopril as Initial Treatment for Hypertension: A Report from the ALLHAT Study

OBJECTIVE—Optimal initial antihypertensive drug therapy in people with the metabolic syndrome is unknown. RESEARCH DESIGN AND METHODS—We conducted a subgroup analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) to compare metabolic, cardiovascular, and renal outcomes in individuals assigned to initial hypertension treatment with a thiazide-like diuretic (chlorthalidone), a calcium channel blocker (CCB; amlodipine), or an ACE inhibitor (lisinopril) in nondiabetic individuals with or without metabolic syndrome. RESULTS—In participants with metabolic syndrome, at 4 years of follow-up, the incidence of newly diagnosed diabetes (fasting glucose ≥126 mg/dl) was 17.1% for chlorthalidone, 16.0% for amlodipine (P = 0.49, chlorthalidone vs. amlodipine) and 12.6% for lisinopril (P < 0.05, lisinopril vs. chlorthalidone). For those without metabolic syndrome, the rate of newly diagnosed diabetes was 7.7% for chlorthalidone, 4.2% for amlodipine, and 4.7% for lisinopril (P < 0.05 for both comparisons). There were no differences in relative risks (RRs) for outcomes with amlodipine compared with chlorthalidone in those with metabolic syndrome; in those without metabolic syndrome, there was a higher risk for heart failure (RR 1.55 [95% CI 1.25–1.35]). In comparison with lisinopril, chlorthalidone was superior in those with metabolic syndrome with respect to heart failure (1.31 [1.04–1.64]) and combined cardiovascular disease (CVD) (1.19 [1.07–1.32]). No significant treatment group–metabolic syndrome interaction was noted. CONCLUSIONS—Despite a less favorable metabolic profile, thiazide-like diuretic initial therapy for hypertension offers similar, and in some instances possibly superior, CVD outcomes in older hypertensive adults with metabolic syndrome, as compared with treatment with CCBs and ACE inhibitors.

Original articleThe Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT): Clinical Center Recruitment Experience

The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) is a randomized clinical outcome trial of antihypertensive and lipid-lowering therapy in a diverse population (including substantial numbers of women and minorities) of 42,419 high-risk hypertensives aged > or = 55 years with a planned mean follow-up of 6 years. In this paper, we describe our experience in the identification, recruitment, and selection of clinical centers for this large simple trial capable of meeting the recruitment goals outlined for ALLHAT, and we highlight factors associated with clinical center performance. Over 135,000 recruitment brochures were mailed to physicians. Requests for information and application packets were received from 9351 (6.8%) interested investigators. A total of 1053 completed applications were received and 909 sites (86%) were eventually approved to join the trial. Of the approved sites, 278 either later declined participation or were never activated, and 8 were closed within a year for lack of enrollment. The final 623 randomizing centers exceeded the trials recruitment goal to enroll at least 40,000 participants into the trial, although the recruitment period was extended 1.5 years longer than planned. Fewer than a quarter of the sites (22.6%) were recruited from academic medical centers or Department of Veterans Affairs Medical Centers. More than half of the sites (54.7%) were private solo or group practices, which contributed 53% of randomized participants. Community health centers comprised about 8% of the ALLHAT sites and 2.9% were part of health maintenance organizations. More than 22% of the principal investigators reported that they had no previous clinical research experience. In summary, ALLHAT was successful in recruiting a diverse group of clinical centers to achieve its patient recruitment goals.

Characteristics and lipid distribution of a large, high-risk, hypertensive population: The Lipid-Lowering component of the Antihypertensive and Lipid-Lowering Treatment to prevent Heart Attack Trial (ALLHAT)

The Antihypertensive and Lipid‐Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) consisted of 42,418 participants randomized to one of four antihypertensive treatment groups: chlorthalidone, amlodipine, lisinopril, or doxazosin. A subset of these participants with fasting low‐density lipoprotein cholesterol levels 100–189 mg/dL were randomized into a lipid‐lowering component: 5170 to receive pravastatin (40 mg daily) and 5185 to receive usual care. This report describes the characteristics and lipid distribution of these participants. There were no important differences between the randomized treatment groups. Women had higher total cholesterol, low‐density lipoprotein cholesterol, and high‐density lipoprotein cholesterol than men. There was a similar finding for black participants compared with whites, except blacks had lower triglycerides. Diabetics had lower high‐density lipoprotein cholesterol and higher triglycerides than nondiabetics, and patients with body mass index <25 kg/m2 had higher high‐density lipoprotein cholesterol but lower low‐density lipoprotein cholesterol and triglycerides than patients with higher body mass index. The success of the randomization of this large, diverse population and the differences in the lipid distributions among its subgroups will allow further understanding of optimal lipid‐lowering treatment.

Management of High Blood Pressure in Clinical Practice: Perceptible Qualitative Differences in Approaches Utilized by Clinicians

The authors recruited a group of physicians from among the investigators participating in the Antihypertensive and Lipid‐Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) with a greater (more successful) or lesser (less successful) proportion of trial patients meeting blood pressure (BP) control goals. The authors utilized qualitative focus group methods to identify similarities and differences in practice behaviors. Successful and less successful physicians had similarities in knowledge and practice behaviors regarding awareness of treatment guidelines, approaches to diagnosis, use of pharmacologic management, and the opinion that systolic BP guidelines should consider a patient’s age. However, there were discernible differences between the two physician groups in their views on doctor‐patient relationships: physicians from the less successful group were more paternalistic with their patients, while physicians from the more successful group were more likely to use a patient‐centered clinical approach to BP awareness and management.

The explosion of morbidity and mortality trials in hypertension

The highlights of each generation of hypertension trials have been varied, but interrelated. The initial hypertension trials focused on middle-aged hypertensive individuals and later on the elderly, with emphasis on diastolic blood pressure and subsequently on systolic blood pressure. Past generations of trials elucidated whether and whom to treat. The current explosion of morbidity and mortality trials in hypertension largely seeks to learn what drugs should be used and to delineate what blood pressure goals should be targeted.