Initiated in 2001 by the National Heart Lung and Blood Institute (NHLBI), ACCORD was an important landmark clinical trial for patients with type 2 diabetes and risk factors for cardiovascular disease; it represented the first large, experimental investigation of several key treatment guidelines that were based on sound epidemiological evidence but had never been subjected to the more rigorous test of an RCT.3 ACCORD study subjects had type 2 diabetes, with a hemoglobin A1c level of at least 7.5%, and met cardiovascular risk criteria including (a) aged 40 years or older with cardiovascular disease or (b) aged 55 years or older with atherosclerosis, albuminuria, left ventricular hypertrophy, or at least 2 cardiovascular disease risk factors (obesity, smoking, dyslipidemia, or hypertension).
2Of the 10,251 ACCORD study subjects, 4,733 met clinical criteria for inclusion in the blood pressure control component of the trial (systolic blood pressure [SBP] between 130 and 180 millimeters mercury [mmHg], taking 3 or fewer antihypertensive medications, and "the equivalent of a 24-hour protein excretion rate of less than 1.0 [grams]"). Patients were randomized to "intensive" therapy targeted to SBP less than 120 mmHg (n = 2,362) or "standard" therapy targeted to SBP less than 140 mmHg (n = 2,371). Patients were treated using "strategies that are currently available in clinical practice" and "drug classes … shown to result in a reduction in cardiovascular events among participants with diabetes."2 At 1-year follow-up, mean SBPs were 119.3 (95% confidence interval [CI] = 118.9-119.7) mmHg and 133.5 (95% CI = 133.1-133.8) mmHg in the intensive-and standard-therapy groups, respectively, a difference that was "significant and sustained" throughout the study. However, in a mean 4.7 years of follow-up, the SBP differences did not translate into significant improvements in the primary endpoint outcome, a composite of nonfatal myocardial infarction (MI), nonfatal stroke, or cardiovascular death; annual rates were 1.87% in intensive therapy and 2.09% in standard therapy (hazard ratio [HR] = 0.88, 95% CI = 0.73-1.06, P = 0.20). Additionally, serious adverse events attributable to antihypertensive treatment, including hypotension, bradycardia or arrhythmia, and hyperkalemia, were more common in the intensive-than standard-therapy arm (3.3% vs. 1.3%, respectively, P < 0.001).