New research was presented at Hypertension 2018, the Joint Hypertension 2018 Scientific Sessions of the American Heart Association (AHA) Council on Hypertension, AHA Council on Kidney in Cardiovascular Disease, and the American Society of Hypertension, from September 6-9 in Chicago. The features below highlight some of the studies that emerged from the conference.
Trends in Refractory Hypertension
Unbiased estimates of the prevalence of refractory hypertension—uncontrolled blood pressure in patients taking five or more types of antihypertensive medications—are lacking in the United States. Researchers assessed eights cycles (1999-2014) of the National Health and Nutrition Examination Survey to estimate the prevalence of refractory hypertension among the hypertensive population. Among all hypertensive individuals, refractory hypertension was found in 0.30%, peaking at 0.54% during the 2005-2006 cycle. No significant trend in prevalence was observed through the study period. Refractory hypertension was not seen in patients younger than 40 and was more common in those who were aged 60 and older than in individuals aged 40-60 (odds ratio [OR], 4.55. While no gender differences were found, Caucasian and African American participants were more likely to have refractory hypertension than those of Hispanic or other descent (OR, 4.63). Participants with chronic kidney disease (CKD) were significantly more likely to have refractory hypertension than those without CKD (OR, 9.88).
Analyzing Hypertensive Crisis
Hypertensive crisis (HTNC)—the potentially life-threatening condition that can develop de novo or as a complication of hypertension—is characterized by a severe, acute increase in blood pressure (BP) to 180/120 mmHg or higher, possibly progressing to end organ damage (EOD) and premature death. Cases with evidence of EOD are classified as hypertensive emergency (HTNE), whereas cases without EOD are classified as hypertensive urgency (HTNU). With data lacking on the prevalence and risk factors of HTNE and HTNU, study investigators conducted a 3-year retrospective, case-controlled study in an inner city population of nearly 1,800 adult emergency room patients with a BP of 200/120 mmHg or higher and controls with hypertension defined by a BP between 140/90 and 200/120 mmHg. Prevalence rates of HTNC and HTNE were 11.4% and 3.2%, respectively, with 28.0% of cases having EOD. Those with HTNC had significantly increased odds of developing acute kidney injury (odds ratio [OR], 1.54), acute or worsening congestive heart failure (OR, 4.91), non-ST elevation myocardial infarction (OR, 2.39), ischemic stroke (OR, 3.27), and hemorrhagic stroke (OR, 4.55). Predictors for EOD were age older than 65, male gender, anemia, chronic kidney disease, and history of stroke and cardiovascular comorbidities.
Intensive BP Treatment Outcomes in Diabetics
Evidence is lacking to support the strategy of lowering blood pressure (BP) in patients with type 2 diabetes. To test the hypothesis that intensive blood pressure treatment prevents or alleviates adverse renal outcomes among diabetic patients, researchers conducted a post-hoc analysis of diabetics with standard glycemic control who were randomly assigned a systolic BP (SBP) treatment target of less than 120 mmHg (intensive treatment) or less than 140 mmHg (standard treatment). At 1 year, the mean SBP was 120.8 mmHg in intensive group and 134.6 in the standard group. Serum creatinine doubling or a greater than 20 mL/min decrease in estimated glomerular filtration rate attributed to intensive treatment occurred in 57.0% of the intensive therapy group, compared with 44.9% of the standard therapy group. No significant differences in three other renal outcomes were observed between the two treatment groups.
HSBPV & Functional Outcomes in ICH Patients
While high in-hospital systolic blood pressure variability (HSBPV) is emerging as a marker of poor outcomes for patients with intracerebral hemorrhage (ICH), data are lacking on the risk of severe disability or death, and pre-hospital factors associated with HSBPV, in this patient population. For a study, researchers assessed more than 120,500 SBP readings among adult, radiologically confirmed primary ICH patients who were followed for 90 days, with a total in-hospital follow-up period of more than 4,900 days. The inter- and intra-patient mean SBP standard deviations were 11.1 and 13.2, respectively. A standard deviation of 13.0 was parameterized as a cut-off for HSBPV. Patients with HSBPV had a 17% higher adjusted risk of 90-day severe disability or death. Older age and female gender were independently associated with HSBPV after controlling for hemorrhage volume, pre-morbid Modified Rankin Scale score, and Glasgow Coma Scale score.
OSA, Carotid Artery Stiffness & COPD
While chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) are both independently associated with increased carotid artery stiffness, the interaction of COPD and OSA in patients with both conditions (overlap syndrome) on carotid artery stiffness remains unknown. The hypotheses that a) patients with overlap syndrome have greater carotid artery stiffness than patients with either COPD or OSA and non-COPD controls and b) patients with overlap syndrome who report use of continuous positive airway pressure (CPAP) have lower carotid artery stiffness than those not using CPAP were tested for a study. Even after adjusting for BMI, participants with overlap syndrome had significantly greater carotid artery stiffness than COPD patients without OSA, non-COP controls with OSA, and non-COPD controls without OSA. When compared with other patient groups, those with overlap syndrome had no observable differences in blood pressure, heart rate, resting oxygen saturation, or nocturnal mean oxygen saturation. No differences were observed in carotid artery stiffness between patients with overlap syndrome who report using or not using CPAP.