Impact of Uncontrolled Hypertension at 3 Months After Intracerebral Hemorrhage

Abstract

Background Survivors of intracerebral hemorrhage (ICH) are at high risk for recurrent stroke, which is associated with blood pressure control. Because most recurrent stroke events occur within 12 to 18 months of the index ICH, rapid blood pressure control is likely to be crucial. We investigated the frequency and prognostic impact of uncontrolled short-term hypertension after ICH. Methods and Results We analyzed data from Massachusetts General Hospital (n=1305) and the University of Hong Kong (n=523). We classified hypertension as controlled, undertreated, or treatment resistant at 3 months after ICH and determined the following: (1) the risk factors for uncontrolled hypertension and (2) whether hypertension control at 3 months is associated with stroke recurrence and mortality. We followed 1828 survivors of ICH for a median of 46.2 months. Only 9 of 234 (4%) recurrent strokes occurred before 3 months after ICH. At 3 months, 713 participants (39%) had controlled hypertension, 755 (41%) had undertreated hypertension, and 360 (20%) had treatment-resistant hypertension. Black, Hispanic, and Asian race/ethnicity and higher blood pressure at time of ICH increased the risk of uncontrolled hypertension at 3 months (all P<0.05). Uncontrolled hypertension at 3 months was associated with recurrent stroke and mortality during long-term follow-up (all P<0.05). Conclusions Among survivors of ICH, >60% had uncontrolled hypertension at 3 months, with undertreatment accounting for the majority of cases. The 3-month blood pressure measurements were associated with higher recurrent stroke risk and mortality. Black, Hispanic, and Asian survivors of ICH and those presenting with severe acute hypertensive response were at highest risk for uncontrolled hypertension.

Keywords: hypertension; intracerebral hemorrhage; stroke.

Conflict of interest statement

Dr Biffi is supported by Massachusetts General Hospital and by K23NS100816. Dr Teo is supported by Queen Mary Hospital and the Hong Kong Neurological Society Scholarship for Young Neurologist. Dr Christopher D. Anderson is supported by R01NS103924, U01NS069763, and American Heart Association 18SFRN34110082; receives sponsored research support from the Massachusetts General Hospital Center for Genomic Medicine and Bayer AG; and has consulted for ApoPharma, Inc. Dr Viswanathan is supported by P50AG005134. Dr Greenberg is supported by R01AG26484. Dr Lau is supported by the Health and Medical Research Fund, Food and Health Bureau, The Government of the Hong Kong SAR; has consulted for Boehringer Ingelheim; and has received grant support from Amgen, Boehringer Ingelheim, Eisai, Pfizer Inc, and Sanofi. Dr Rosand is supported by R01NS036695, UM1HG008895, R01NS093870, and R24NS092983 and has consulted for New Beta Innovations, Boehringer Ingelheim, and Pfizer Inc. The remaining authors have no disclosures to report.

Figures

Figure 1. Flow diagram of study inclusion and exclusion criteria.

BP indicates blood pressure; CT, computed tomography; EMR, electronic medical record; HK‐ICH, Intracerebral Hemorrhage Study at University of Hong Kong; HTN, hypertension; ICH, intracerebral hemorrhage; and MGH‐ICH, Intracerebral Hemorrhage Study at Massachusetts General Hospital.

Figure 2. Recurrent stroke risk after ICH.

Incidence of recurrent ICH and ischemic stroke after index ICH in cases per 100‐person years in both studies combined (A) and separately in the Intracerebral Hemorrhage Study at Massachusetts General Hospital (B) and the Intracerebral Hemorrhage Study at University of Hong Kong (C). Incidence rates were calculated as number of recurrent events (recurrent ICH or ischemic stroke) occurring between follow‐up time points (ie, 6‐month time periods, except 3 months between index ICH and first follow‐up) over the sum of the follow‐up period for all individuals remaining in the study during that time period, and finally normalized to 100 person‐years. Number of ICH and ischemic stroke events are presented below each graph. ICH indicates intracerebral hemorrhage; and Isch., ischemic.

Figure 3. Hypertension control 3 months after ICH.

Anti‐HTN indicates antihypertensive; DBP, diastolic blood pressure; HK‐ICH, Intracerebral Hemorrhage Study at University of Hong Kong; ICH, intracerebral hemorrhage; MGH‐ICH, Intracerebral Hemorrhage Study at Massachusetts General Hospital; and SBP, systolic blood pressure.

Figure 4. Correlation between BP measured 3 months after ICH and average BP during long‐term follow‐up.

Correlation scatter plots for systolic BP (A) and diastolic BP (B) at 3 months after ICH compared with the average values during overall study follow‐up. BP indicates blood pressure; Corr. Coeff., correlation coefficient; and ICH, intracerebral hemorrhage.

Figure 5. Hypertension control at 3 months and risk of recurrent stroke after ICH.

Cumulative incidence function curves for stroke recurrence risk (all cause; A), recurrent ICH (B), ischemic stroke (C), and mortality (D) based on hypertension control status (controlled, undertreated, or treatment resistant) at 3 months from index ICH. All survival analyses have 3 months after ICH as time zero. Sample size at each time point for the participating studies and the combined study sample during follow‐up is listed above the horizontal axis. HK‐ICH indicates Intracerebral Hemorrhage Study at University of Hong Kong; ICH, intracerebral hemorrhage; MGH‐ICH, Intracerebral Hemorrhage Study at Massachusetts General Hospital; and n, sample size.