Biological and Social Determinants of Hypertension Severity Before vs After Intracerebral Hemorrhage.

BACKGROUND AND OBJECTIVES: Although blood pressure (BP) control is considered the most effective measure to prevent functional decline after intracerebral hemorrhage (ICH), fewer than half of survivors achieve treatment goals. We hypothesized that long-term (i.e., prehemorrhage) hypertension severity may be a crucial factor in explaining poor BP control after ICH. We investigated changes in hypertension severity after vs before ICH using latent class analysis (LCA) and identified patient characteristics predictive of individuals' BP trajectories. METHODS: We analyzed data for ICH survivors enrolled in a study conducted at Massachusetts General Hospital (MGH) from 2002 to 2019 in Boston, a high-resource setting with near-universal medical insurance coverage. We captured BP measurements in the 12 months preceding and following the acute ICH hospitalization. Using LCA, we identified patient groups (classes) based on changes in hypertension severity over time in an unbiased manner. We then created multinomial logistic regression models to identify patient factors associated with these classes. RESULTS: Among 336 participants, the average age was 74.4 years, 166 (49%) were male, and 288 (86%) self-reported White race/ethnicity. LCA identified 3 patient classes, corresponding to minimal (n = 114, 34%), intermediate (n = 128, 38%), and substantial (n = 94, 28%) improvement in hypertension severity after vs before ICH. Survivors with undertreated (relative risk ratio [RRR] 0.05, 95% CI 0.01-0.23) or resistant (RRR 0.03, 95% CI 0.01-0.06) hypertension before ICH were less likely to experience substantial improvement afterwards. Residents of high-income neighborhoods were more likely to experience substantial improvement (RRR 1.14 per $10,000, 95% CI 1.02-1.28). Black, Hispanic, and Asian participants with uncontrolled hypertension before ICH were more likely to experience minimal improvement after hemorrhagic stroke (interaction p < 0.001). DISCUSSION: Most ICH survivors do not display consistent improvement in hypertension severity after hemorrhagic stroke. BP control after ICH is profoundly influenced by patient characteristics predating the hemorrhage, chiefly prestroke hypertension severity and socioeconomic status. Neighborhood income was associated with hypertension severity after ICH in a high-resource setting with near-universal health care coverage. These findings likely contribute to previously documented racial/ethnic disparities in BP control and clinical outcomes following ICH.

Genetic overlap and causal inferences between kidney function and cerebrovascular disease.

OBJECTIVE: Leveraging large-scale genetic data, we aimed to identify shared pathogenic mechanisms and causal relationships between impaired kidney function and cerebrovascular disease phenotypes. METHODS: We used summary statistics from genome-wide association studies (GWAS) of kidney function traits (chronic kidney disease diagnosis, estimated glomerular filtration rate [eGFR], and urinary albumin-to-creatinine ratio [UACR]) and cerebrovascular disease phenotypes (ischemic stroke and its subtypes, intracerebral hemorrhage [ICH], and white matter hyperintensities [WMH] on brain MRI). We (1) tested the genetic overlap between them with polygenic risk scores (PRS), (2) searched for common pleiotropic loci with pairwise GWAS analyses, and (3) explored causal associations by employing 2-sample Mendelian randomization. RESULTS: A PRS for lower eGFR was associated with higher large artery stroke (LAS) risk (p = 1 × 10-4). Multiple pleiotropic loci were identified between kidney function traits and cerebrovascular disease phenotypes, with 12q24 associated with eGFR and both LAS and small vessel stroke (SVS), and 2q33 associated with UACR and both SVS and WMH. Mendelian randomization revealed associations of both lower eGFR (odds ratio [OR] per 1-log decrement, 2.10; 95% confidence interval [CI], 1.38-3.21) and higher UACR (OR per 1-log increment, 2.35; 95% CI, 1.12-4.94) with a higher risk of LAS, as well as between higher UACR and higher risk of ICH. CONCLUSIONS: Impaired kidney function, as assessed by decreased eGFR and increased UACR, may be causally involved in the pathogenesis of LAS. Increased UACR, previously proposed as a marker of systemic small vessel disease, is involved in ICH risk and shares a genetic risk factor at 2q33 with manifestations of cerebral small vessel disease.