Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH) II: Design, Methods, and Rationale

Abstract

The December 2003 report from the National Institute of Neurological Disorders and Stroke (NINDS) Workshop on priorities for clinical research in intracerebral hemorrhage (ICH) recommended clinical trials for evaluation of blood pressure management in acute ICH as a leading priority. The Special Writing Group of the Stroke Council of the American Heart Association in 1999 and 2007 emphasized the need for clinical trials to ensure evidence-based treatment of acute hypertensive response in ICH. To address important gaps in knowledge, we conducted a pilot study funded by the NINDS, Antihypertensive Treatment of Acute Cerebral Hemorrhage (ATACH) I Trial, during 2004-2008 to determine the appropriate level of systolic blood pressure (SBP) reduction. We now have initiated a multi-center, randomized Phase III trial, the ATACH II Trial, to definitively determine the efficacy of early, intensive, antihypertensive treatment using intravenous (IV) nicardipine initiated within 3h of onset of ICH and continued for the next 24h in subjects with spontaneous supratentorial ICH. The primary hypothesis of this large (N=1,280), streamlined, and focused trial is that SBP reduction to ≤140mm Hg reduces the likelihood of death or disability at 3months after ICH, defined by modified Rankin scale score of 4-6, by at least 10% absolute compared to standard SBP reduction to ≤180mm Hg. The ATACH II trial is a natural extension of numerous case series, the subsequent ATACH I pilot trial, and a preliminary, randomized, and controlled trial in this patient population funded by the Australian National Health and Medical Research Council. Both trials recently confirmed the safety and tolerability of both the regimen and goals of antihypertensive treatment in acutely hypertensive patients with ICH, as proposed in the present trial. The underlying mechanism for this expected beneficial effect of intensive treatment is presumably mediated through reduction of the rate and magnitude of hematoma expansion observed in approximately 73% of the patients with acute ICH. The Australian trial provided preliminary evidence of attenuation of hematoma expansion with intensive SBP reduction. The ATACH II trial will have important public health implications by providing evidence of, or lack thereof, regarding the efficacy and safety of acute antihypertensive treatment in subjects with ICH. This treatment represents a strategy that can be made widely available without the need for specialized equipment and personnel, and therefore, can make a major impact upon clinical practice for treating patients with ICH.