By Deborah J. DeWaay, MD, FACP
Associate Professor, Medical University of South Carolina, Charleston, SC
Dr. DeWaay reports no financial relationships in this field of study
SYNOPSIS: Inadequate blood pressure control in intracranial hemorrhage (ICH) survivors was associated with recurrent ICH.
SOURCE: Biffi A, Anderson C, Battey T, Ayres A, Greenberg S, Viswanathan A, Rosand J. Association Between Blood Pressure Control and Risk of Recurrent Intracerebral Hemorrhage. JAMA. 2015; 314(9):904-912
Fifty percent of stroke-related morbidity and mortality are related to intracerebral hemorrhage (ICH). ICH secondary to arteriolosclerosis usually occurs in the deep structures of the brain, such as the basal ganglia, thalami or brainstem. In contrast, ICH secondary to cerebral amyloid angiopathy tends to occur in the “lobar” or cortical-subcortical regions. Improving secondary prevention of ICH is important because a recurrent bleed is usually more devastating than the first occurrence.
This was a single-center longitudinal cohort study of patients with ICH. Patients were included in the study if they were diagnosed with an ICH confirmed by CT scan, had symptoms that began <24 hours prior to presentation, and were ≥ 18 years old over a 7 year period. Patients with an ICH that was secondary to trauma, had a conversion of an ischemic infarct, had a rupture of an aneurysm of arteriovenous malformation or tumor were excluded. A lobar ICH was defined as occurring in the cerebral cortex ± underlying white matter. An ICH that occurred in the basal ganglia, thalami or brainstem was labelled a nonlobar ICH. In order to determine if a patients’ blood pressure was controlled and if any recurrent strokes occurred, all participants or caregivers were interviewed at 3, 6, 9, 12 months and every 6 months afterwards. In addition, the investigators obtained any new imaging and blood pressure readings were obtained from the patient, the electronic health record (EMR) and when necessary external medical records. Patients were excluded if more than one blood pressure reading was missing within a given 6 month period or if there was a discrepancy between the EMR medication record and the patient’s self-reported list. In addition to interviewing the patient, caregivers and accessing the EMR for data on deaths and new strokes, the Social Security Death Index was also queried.
In order to analyze the relationship between blood pressure and recurrent ICH the authors generated 4-time varying exposures. The rates of ICH recurrence per 1000 person-years were computed and compared to the patients’ blood pressure being adequately or inadequately controlled as determined by 4 blood pressure variables. First, authors used the American Heart Associate/American Stroke Association guidelines (AHA/ASA) and the patients’ blood pressures to create a dichotomous variable. The goal for non-diabetics was less than 140/90. For diabetics the goal was less than 130/80. Second, the hypertension stage of the patient based on the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure 7 (JNC 7) criteria. Third and fourth, systolic and diastolic blood pressures were used as continuous variables respectively.
1145 of 2278 patients who were screened were enrolled: 505 lobar ICH and 640 nonlobar ICH. 102 of the lobar ICH patients had a recurrence. 44 of the nonlobar ICH patients had a recurrence. Adequate blood pressure control was defined by the AHA/ASA guidelines. 54.6% of patients achieved goal for at least 1 measurement during followup. 43.2% of patients consistently had controlled blood pressure at all available points. The rate of consistent blood pressure control was not significantly different between the two location types. There was no significant difference between type of antihypertensive used, number of antihypertensives and location of stroke recurrence (lobar vs. nonlobar).
A bivariable analysis showed that inadequate blood pressure was associated with recurrent lobar ICH (HR 3.19 [CI 1.42-7.16] p = .005]. This significant difference was also present with multivariate analysis. Lobar ICH rates were 49 per 1000 person-years with adequate blood-pressure control versus 84 per 1000 person-years in those without. In addition, a bivariable analysis showed that inadequate blood pressure was associated with recurrent non-lobar ICH (HR 3.99 [CI 1.16-13.76] p = .03]. Non-lobar ICH rates were 27 per 1000 person-years with adequate blood-pressure control versus 52 per 1000 person-years in those without. This significant difference was also present with multivariate analysis. Only 50% of participants had controlled blood pressure per the guidelines.
In conclusion, there appears to be an association between uncontrolled blood pressure and recurrent ICH irrespective of location. This association became stronger as the stage of hypertension, as defined per the JNC-7 guidelines, was more severe. These findings suggest that secondary prevention with controlled blood pressure maybe very important with this population. Limitations of this study include the authors’ ability to capture the correct blood pressure. Also, it is a single centered study. Lastly, this study points to a possible association, not causality.
COMMENTARY
Although a randomized controlled trial is necessary to validate this study, the concept remains important. There is great variability in managing blood pressure control in a hospitalized patient. Additionally, little evidence shows tight blood pressure control as necessary except in certain populations such as severe kidney injury and heart failure, benefits patient outcomes. Patients with a history of intracerebral hemorrhage may be another population where tighter blood pressure control during hospitalization may be important. Discharge planning and coordination remain struggles in our current medical system. The challenge for hospitalists making sure the patient understands their medication regimen, and has followup with a primary care provider especially in times of high patient volume and short hospitalizations remains. Good discharge planning including close followup with a primary care provider, helping the patient understand their medication regimen and having a good blood pressure regimen will be even more important in the ICH patient population in order to give them the best chance of having good blood pressure control post-hospitalization.
