Abstract
Blood pressure is commonly elevated at the hospital emergency department (ED), especially among hypertensive patients. The aim of the study was to determine the association between ED systolic blood pressure (SBP) and in‐hospital mortality among hypertensive patients. The authors retrospectively retrieved records of hypertensive patients who were hospitalized during a seven‐year period. The authors examined the association between SBP and in‐hospital mortality rate, adjusted for demographics, heart rate, comorbidities, laboratory results, and hospital ward. Overall, 96 423 patients were included. Compared to patients with SBP 110‐139 mm Hg, the adjusted odds ratios were 4.1 (95% CI, 3.7‐4.6) with SBP <90, 1.6 (95% CI, 1.4‐1.7) with SBP 90‐109, 0.7 (95% CI, 0.6‐0.7) with SBP 140‐159, 0.7 (95% CI, 0.6‐0.7) with SBP 160‐179, 0.7 (95% CI, 0.6‐0.8) with SBP 180‐199, 0.9 (95% CI, 0.7‐1.1) with SBP 200‐219, and 1.1 (95% CI, 0.7‐1.7) with SBP ≥220 mm Hg. Thus, SBP levels of 110‐139 mm Hg were associated with higher in‐hospital mortality in comparison with elevated SBP up to 200 mm Hg.
Keywords: blood pressure, emergency departments, essential, hypertension, in‐hospital mortality
1. INTRODUCTION
Hypertension is a prevalent disease, and it is a major risk factor accounting for high rates of morbidity and mortality. Almost one fourth of all US adult emergency department (ED) visits are hypertension‐related. According to the Centers for Disease Control and Prevention (CDC), blood pressure (BP) is severely elevated in 16.3% and moderately elevated in 27.2% of hospital ED visits.1 The prevalence of high BP varies between different clinical conditions and can reach a high rate of 78% in stroke patients.2
Elevated BP as a primary diagnosis is responsible for approximately 1% of ED visits.3 The incidental finding of elevated BP during the ED visit may be the result of factors such as pain or anxiety4; however, 50%‐70% of ED cases who have elevated BP entail patients with chronic hypertension.5 Several studies showed that in normotensive patients, elevated ED BP may reveal unknown hypertension.6 Literature to date has mainly focused on the outcome of the primary diagnosis or the primary complaint of hypertension in the ED and has demonstrated a good prognosis with a low mortality rate.7 One study suggested that the treatment of severe hypertension should be managed in the ED.8 A differentiation has been made between urgency hypertension, which is characterized by lack of symptoms, vs emergency hypertension, which entails end‐organ damage, with a worse prognosis for the latter.9
Patients with chronic hypertension can be differentiated from normotensive patients in regard to baseline BP measurements,10 the autonomic nervous system, and the elasticity of the arteries.11 The prognostic significance of elevated BP among this specific population needs to be addressed.
It is well known that low systolic BP (SBP) (<90 mm Hg) in the ED is associated with poor outcome as it indicates shock.12 It is believed that normal SBP in the ED is adequate and very high SBP in the ED is associated with worse prognosis, although this question has not been adequately investigated to date except in selected conditions such as acute heart failure13 or acute infection.14
The aim of our study was to determine the association between SBP in the ED and in‐hospital mortality among hypertensive patients.
2. MATERIALS AND METHODS
2.1. Study setting
This retrospective study was conducted at one tertiary care hospital. This hospital has a separate general ED, gynecology ED, pediatric ED, and an ophthalmology ED. Our study has focused on the general ED, which admits adult patients (≥18 years) and trauma at all ages. This acute care hospital has approximately 1100 beds and 120 000 adult ED visits per year. Our hospital's Institutional Review Board (IRB) approved this retrospective cohort study. The IRB committee waived informed consent of included patients.
2.2. Study design
We aimed to evaluate the association between ED SBP and in‐hospital mortality in patients with a known diagnosis of hypertension. For this purpose, we retrieved data for all the patients who presented to our ED and were hospitalized during a six‐year period from January 1, 2012, to December 31, 2018.
For each patient, we retrieved the following primary variables from the hospital's electronic medical records (EMR):
Information regarding hospitalization; a known chronic hypertension diagnosis using International Classification of Disease, 9th Revision, Clinical Modification (ICD‐9‐CM) codes (401.1, 401.9); patients' initial SBP levels obtained at presentation to the ED; and in‐hospital mortality record.
Secondary variables that we retrieved from the EMR included:
Demographics: age and sex; admission date; comorbidities, coded using ICD‐9‐CM codes and grouped using the diagnostic clinical classification software (CCS) coding,15 included coronary atherosclerotic disease or ischemic heart disease (IHD), diabetes mellitus (DM), chronic renal failure (CRF), congestive heart failure (CHF) or pulmonary edema, and chronic obstructive pulmonary disease (COPD); home medication usage coded by the World Health Organization (WHO) Anatomical Therapeutic Chemical (ATC) classification system; vital signs’ initial measurements obtained at presentation to the ED: temperature (T°), heart rate (HR), SBP, and diastolic blood pressure (DBP); laboratory results obtained in the ED: hemoglobin (HB), white blood cells (WBC), blood urea nitrogen (BUN), creatinine (Cr), glucose, sodium (Na), and potassium (K); and the ward in which the patient was hospitalized. We grouped hospitalization wards into internal medicine wards, surgical wards (general surgery; orthopedic; plastic surgery; urology; ear, nose, and throat; and thoracic surgery), and other wards (geriatrics, cardiology, neurology, and dermatology).
We analyzed hospitalized patients aged 18‐100 years with known hypertension. We excluded patients under the age of 18 or over the age of 100 and patients with missing variables values.
Patients were grouped into eight SBP subgroups according to initial ED SBP measurements: <90, 90‐109, 110‐139, 140‐159, 160‐179, 180‐199, 200‐219, and ≥220 mm Hg.
2.3. Statistical analysis
Patient characteristics were summarized using descriptive statistics. Continuous variables were compared using either the unpaired t test to compare two groups or 1‐way analysis of variance (ANOVA) to compare more than two groups. Categorical variables were compared using the chi‐square test.
We compared the primary outcome of in‐hospital mortality rates between SBP subgroups using one‐way analysis of variance (ANOVA), which is the most common analytical method for comparing differences in the means of 3 or more groups.16 Subanalyses were performed for age (above and below 65), sex, ward of hospitalization, and comorbidities. We also compared between patients who were included in the study and patients who were excluded due to some missing data.
We evaluated the independent effect of SBP on in‐hospital mortality using multivariable logistic regression model. This model was adjusted for age, sex, heart rate, background diagnoses (IHD, DM, CRF, CHF, and COPD), home medication usage, laboratory results (HB, WBC, BUN, Cr, Na, and K), and hospitalization wards. For the model analysis, we considered the subgroup for SBP 110‐139 mm Hg, as the reference group, and calculated adjusted odds ratios for SBP groups in comparison with the reference group. We computed the C statistic of the model.
All analyses were conducted with Python (version 3.6.5 64 bits). The following open‐source Python packages were used for analyses: Pandas version 0.24.2, scikit‐learn version 0.20.3, and StatsModels version is 0.9.0.
Statistical significance was established at a 2‐sided P < .05.
3. RESULTS
3.1. Patients' characteristics
During the study period, we identified 799 522 unique adult patients ED visits, and of these 287 815 (36.0%) were hospitalized. Of hospitalized patients, 106 135 (36.9%) had known chronic hypertension. After excluding 9712 patients with missing values, our final sample included 96 423 patients. Characteristics of the population according to SBP subgrouping are given in Table 1. A comparison of the characteristics of patients who were included in the study and patients who were excluded due to some missing data is presented in Table S1.
Table 1.
Baseline characteristics of patients presenting to the hospital emergency department according to the different blood pressure groups
| Characteristic | Entire cohort | SBP <90 mm Hg | SBP 90‐109 mm Hg | SBP 110‐139 mm Hg | SBP 140‐159 mm Hg | SBP 160‐179 mm Hg | SBP 180‐199 mm Hg | SBP 200‐219 mm Hg | SBP >220 mm Hg | P value |
|---|---|---|---|---|---|---|---|---|---|---|
| Number of patients in subgroup (%) | 96 423 | 2335 (2.4%) | 9977 (10.3%) | 35 234 (36.5%) | 25 139 (26.1%) | 14 912 (15.5%) | 6378 (6.6%) | 1863 (1.9%) | 585 (0.6%) | |
| Age (years), mean (SD) | 75.6 (12.1) | 77.7 (11.5) | 76.8 (11.7) | 75.3 (12.3) | 75.1 (12.2) | 75.7 (11.9) | 76.7 (11.6) | 76.4 (12.1) | 75.3 (13.1) | <.001 |
| Female sex, N. (%) | 45 932 (47.6) | 1092 (46.8) | 4435 (44.5) | 15 919 (45.2) | 12 183 (48.5) | 7390 (49.6) | 3508 (55.0) | 1059 (56.8) | 346 (59.1) | <.001 |
| Medical history | ||||||||||
| IHD, N. (%) | 35 037 (36.3) | 865 (37.0) | 3968 (39.8) | 13 124 (37.2) | 8863 (35.3) | 5259 (35.3) | 2160 (33.9) | 625 (33.5) | 173 (29.6) | <.001 |
| CHF, N. (%) | 29 992 (31.1) | 864 (37.0) | 3720 (37.3) | 11 397 (32.3) | 7326 (29.1) | 4189 (28.1) | 1840 (28.8) | 506 (27.2) | 150 (25.6) | <.001 |
| DM, N. (%) | 42 409 (44.0) | 1003 (43.0) | 4297 (43.1) | 15 267 (43.3) | 11 153 (44.4) | 6671 (44.7) | 2891 (45.3) | 866 (46.5) | 261 (44.6) | <.001 |
| CRF, N. (%) | 17 105 (17.7) | 533 (22.8) | 2155 (21.6) | 6283 (17.8) | 3998 (15.9) | 2459 (16.5) | 1170 (18.3) | 369 (19.8) | 138 (23.6) | <.001 |
| COPD, N. (%) | 8617 (8.9) | 276 (11.8) | 1070 (10.7) | 3321 (9.4) | 2142 (8.5) | 1132 (7.6) | 517 (8.1) | 120 (6.4) | 39 (6.7) | <.001 |
| Home medication usage | ||||||||||
| ACE‐I, N. (%) | 31 645 (32.8) | 716 (30.7) | 3175 (31.8) | 11 316 (32.1) | 8387 (33.4) | 5020 (33.7) | 2173 (34.1) | 648 (34.8) | 210 (35.9) | <.001 |
| Angiotensin receptor blockers, N. (%) | 24 032 (24.9) | 397 (17.0) | 2029 (20.3) | 8148 (23.1) | 6605 (26.3) | 4245 (28.5) | 1840 (28.8) | 596 (32.0) | 172 (29.4) | <.001 |
| Beta blockers, N. (%) | 53 373 (55.4) | 1329 (56.9) | 5932 (59.5) | 19 608 (55.7) | 13 508 (53.7) | 8078 (54.2) | 3534 (55.4) | 1049 (56.3) | 335 (57.3) | <.001 |
| Calcium channel blockers, N. (%) | 32 916 (34.1) | 499 (21.4) | 2448 (24.5) | 11 218 (31.8) | 9278 (36.9) | 5763 (38.6) | 2683 (42.1) | 768 (41.2) | 259 (44.3) | <.001 |
| Diuretics, N. (%) | 6442 (6.7) | 114 (4.9) | 610 (6.1) | 2239 (6.4) | 1757 (7.0) | 1024 (6.9) | 471 (7.4) | 175 (9.4) | 52 (8.9) | <.001 |
Abbreviations: ACE‐I, angiotensin‐converting enzyme inhibitors; CHF, chronic heart failure; COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; DM, diabetes mellitus; IHD, ischemic heart disease; SBP, systolic blood pressure; SD, standard deviation.
Patients had a mean age of 75.6 ± 12.1 years; 47.6% were women. The mean SBP and interquartile range (IQR) were 141.0 ± 28.3 mm Hg and 121‐159 mm Hg, respectively. The mean DBP and IQR were 73.5 ± 15.6 mm Hg and 64‐83 mm Hg, respectively. Most patients (63 155) were hospitalized in internal medicine wards, 13 355 patients were hospitalized in surgical wards, and 19 913 patients were hospitalized in other wards. The median number of days between admission and death in the hospital was 4 (IQR 1‐9 days).
Table 2 presents the vital signs and laboratory results upon admission to the ED for the different SBP subgroups. It should be noted that the ANOVA significant P values in Tables 1 and 2 are likely to be due to the large number of patients in the study.
Table 2.
Vital signs and laboratory tests upon presentation for the different systolic blood pressure groups
| Variables | Entire cohort | SBP <90 mm Hg | SBP 90‐109 mm Hg | SBP 110‐139 mm Hg | SBP 140 ‐159 mm Hg | SBP 160 ‐179 mm Hg | SBP 180 ‐199 mm Hg | SBP 200 ‐219 mm Hg | SBP >220 mm Hg | P value |
|---|---|---|---|---|---|---|---|---|---|---|
| Vital signs | ||||||||||
| SBP (mm Hg), mean (SD) | 141.1 (28.3) | 78.3 (10.4) | 101.3 (5.5) | 125.7 (8.4) | 149.3 (5.6) | 168.3 (5.7) | 187.5 (5.5) | 207.4 (5.6) | 229.9 (10.8) | <.001 |
| DBP (mm Hg), mean (SD) | 73.6 (15.6) | 48.8 (12.4) | 60.7 (10.5) | 70.5 (12.3) | 76.4 (13.6) | 80.9 (14.6) | 84.1 (16.5) | 90.1 (19.1) | 97.6 (22.9) | <.001 |
| Heart rate (b/min), mean (SD) | 82.0 (19.4) | 87.4 (24.4) | 85.4 (21.3) | 83.0 (19.7) | 81.1 (18.7) | 80.0 (17.9) | 79.0 (17.6) | 78.7 (17.7) | 80.0 (19.6) | <.001 |
| Temperature (Celsius), mean (SD), | 36.9 (0.7) | 36.8 (1.2) | 36.9 (0.8) | 37.0 (0.7) | 36.9 (0.6) | 36.9 (0.6) | 36.8 (0.6) | 36.8 (0.5) | 36.8 (0.6) | <.001 |
| Laboratory values | ||||||||||
| HGB (gr/dL), mean (SD) | 11.9 (2.1) | 11.0 (2.3) | 11.3 (2.2) | 11.8 (2.1) | 12.1 (2.0) | 12.3 (2.0) | 12.3 (2.0) | 12.4 (1.9) | 12.6 (2.0) | <.001 |
| WBC (micL), mean (SD) | 10.6 (7.4) | 13.4 (9.9) | 11.6 (8.5) | 10.6 (7.0) | 10.2 (7.1) | 10.1 (7.8) | 10.2 (6.9) | 10.3 (8.6) | 10.4 (5.1) | <.001 |
| Urea (mg/dL), mean (SD) | 63.6 (45.4) | 103.3 (72.0) | 81.3 (56.0) | 64.7 (45.7) | 57.5 (39.4) | 56.6 (38.2) | 57.1 (37.4) | 58.0 (37.6) | 62.6 (38.5) | <.001 |
| Cr (mg/dL), mean (SD) | 1.4 (1.2) | 2.1 (1.6) | 1.7 (1.3) | 1.4 (1.1) | 1.3 (1.1) | 1.4 (1.2) | 1.4 (1.3) | 1.5 (1.4) | 1.7 (1.6) | <.001 |
| Glc (mg/dL), mean (SD) | 154.3 (80.8) | 170.2 (104.3) | 156.7 (86.1) | 152.7 (81.4) | 152.3 (76.6) | 153.6 (76.9) | 159.0 (81.7) | 162.9 (81.7) | 166.0 (85.9) | <.001 |
| Na (mmo/L), mean (SD) | 135.9 (5.2) | 136.0 (7.5) | 135.4 (6.0) | 135.9 (5.2) | 136.0 (4.8) | 136.1 (4.9) | 135.9 (5.1) | 136.0 (4.8) | 136.0 (5.0) | <.001 |
| K (mmol/L), mean (SD) | 4.5 (0.8) | 4.7 (1.0) | 4.5 (0.9) | 4.5 (0.8) | 4.5 (0.7) | 4.5 (0.7) | 4.5 (0.7) | 4.4 (0.8) | 4.5 (0.8) | <.001 |
Abbreviations: Cr, creatinine; DBP, diastolic blood pressure; Glc, glucose; HGB, hemoglobin; K, potassium; Na, sodium; SBP, systolic blood pressure; SD, standard deviation; WBC, white blood cells.
3.2. In‐hospital Mortality
Our logistic regression model had a C statistic of 0.821 for predicting in‐hospital mortality rates. The in‐hospital mortality rate was 5.0% for the entire cohort. A “hockey stick” pattern of association was observed between ED admission SBP and in‐hospital mortality. In comparison with the reference subgroup of patients with SBP 110‐139 mm Hg, higher mortality rates were recorded in those with SBP <110 mm Hg and lower mortality rates were recorded in those with SBP of 140‐219 mm Hg. A non‐significant increase in adjusted mortality rates was observed in those with SBP ≥220 mm Hg (Table 3). Adjusted mortality rates present a similar “hockey stick” pattern to crude mortality rates. Compared to normal SBP range of 110‐139 mm Hg, higher adjusted odds ratios were observed in SBP <110 mm Hg, and lower adjusted odds ratios were observed in SBP range of 140‐199 mm Hg.
Table 3.
Unadjusted and adjusted outcomes of patients presenting to the hospital emergency department for the different blood pressure groups
| SBP <90 mm Hg | SBP 90‐109 mm Hg | SBP 110‐139 mm Hg | SBP 140‐159 mm Hg | SBP 160‐179 mm Hg | SBP 180‐199 mm Hg | SBP 200‐219 mm Hg | SBP ≥220 mm Hg | |
|---|---|---|---|---|---|---|---|---|
| In‐hospital mortality, N. (%) | 628 (26.9) | 1033 (10.4) | 1722 (4.9) | 732 (2.9) | 397 (2.7) | 178 (2.8) | 62 (3.3) | 25 (4.3) |
| Adjusted odds ratios (95% CI, P value) | 4.1 (3.7‐4.6, <0.001) | 1.6 (1.4‐1.7, <0.001) | 1 | 0.7 (0.6‐0.7, <0.001) | 0.7 (0.6‐0.7, <0.001) | 0.7 (0.6‐0.8, <0.001) | 0.9 (0.7‐1.1, 0.295) | 1.1 (0.7‐1.7, 0.645) |
Adjustment was made for age, sex, heart rate, background diagnoses (IHD, DM, CRF, CHF, and COPD), home medication usage, laboratory results (HB, WBC, BUN, Cr, Na, and K), and hospitalization wards
Abbreviation: SBP, systolic blood pressure.
Subgroup analysis by age, sex, ward of hospitalization, and the presence of diabetes mellitus yielded the same “hockey stick” pattern of association between ED SBP and in‐hospital mortality (Figure 1). The rate of in‐hospital mortality stratified by SBP groups and comorbidities is presented in Table 4.
Figure 1.
Subanalysis by age (A), sex (B), ward of hospitalization (C) and the presence of diabetes mellitus (D) for in‐hospital mortality according to systolic blood pressure in the emergency department
Table 4.
In‐hospital mortality of patients presenting to the hospital emergency department for the different
| SBP <90 mm Hg | SBP 90‐109 mm Hg | SBP 110‐139 mm Hg | SBP 140‐159 mm Hg | SBP 160‐179 mm Hg | SBP 180‐199 mm Hg | SBP 200‐219 mm Hg | SBP ≥220 mm Hg | P value | |
|---|---|---|---|---|---|---|---|---|---|
| IHD Death/Total (%) | 229/865 (26.5) | 394/3968 (9.9) | 612/13124 (4.7) | 259/8863 (2.9) | 139/5259 (2.6) | 61/2160 (2.8) | 21/625 (3.4) | 8/173 (4.6) | <.001 |
| CHF Death/Total (%) | 249/864 (28.8) | 424/3720 (11.4) | 679/11397 (6.0) | 276/7326 (3.8) | 143/4189 (3.4) | 60/1840 (3.3) | 20/506 (4.0) | 6/150 (4.0) | <.001 |
| DM Death/Total (%) | 272/1003 (27.1) | 410/4297 (9.5) | 765/15267 (5.0) | 303/11153 (2.7) | 174/6671 (2.6) | 87/2891 (3.0) | 34/866 (3.9) | 11/261 (4.2) | <.001 |
| CRF Death/Total (%) | 166/533 (31.1) | 264/2155 (12.3) | 439/6283 (7.0) | 179/3998 (4.5) | 97/2459 (3.9) | 47/1170 (4.0) | 18/369 (4.9) | 9/138 (6.5) | <.001 |
| COPD Death/Total (%) | 63/276 (22.8) | 112/1070 (10.5) | 203/3321 (6.1) | 78/2142 (3.6) | 34/1132 (3.0) | 15/517 (2.9) | 1/120 (0.8) | 4/39 (10.3) | <.001 |
Blood pressure groups stratified by patients’ comorbidities.
Abbreviation: CHF, chronic heart failure; COPD, chronic obstructive pulmonary disease; CRF, chronic renal failure; DM, diabetes mellitus; IHD, ischemic heart disease; SBP, systolic blood pressure.
4. DISCUSSION
In this large one‐center retrospective cohort study, we have found that in hospitalized hypertensive patients, the rate of in‐hospital mortality expressed a “hockey stick” pattern of association with SBP levels in the ED. SBP values lower than 110 showed significantly higher mortality rates; SBP values in the range of 140‐219 mm Hg were associated with lower mortality compared to the normal range of 110‐139 mm Hg. SBP values higher than 220 mm Hg showed a slight non‐significant increase in adjusted mortality rate. This association was unrelated to age, sex, ward of hospitalization, and underlying diseases.
Previous studies have demonstrated high incidence of elevated ED BP levels1, 17 also in known hypertensive patients.5, 17, 18, 19 Elevated BP levels in the ED are related to stress, and the prognostic value of elevated SBP in the ED is not clear. Elevated BP levels may have different meanings in normotensive and hypertensive patients. We therefore evaluated the association between in‐hospital mortality and SBP in the ED in hospitalized hypertensive patients. We included in our study only hypertensive patients since we preferred to study a more homogenous population.
It is well known that shock is associated with increased mortality.20 Hypotension with SBP of ≤90 mm Hg is a widely accepted hallmark of possible circulatory failure and if persistent will lead to shock.12 Regarding the association between non‐shock BP measurements and post‐admission mortality, several studies focused on heart failure patients and demonstrated an inverse association between short‐ and long‐term mortality and elevated SBP during hospital admission.13, 21, 22, 23, 24 In their large cohort study (56 942 patients), Vidan et al demonstrated that higher SBP on admission is associated with significantly lower 30‐day and 1‐year mortality in patients hospitalized for heart failure. In their study, 30‐day mortality rates were 34.1%, 18.6%, 10.1%, 5.7%, 4.4%, and 2.9% for SBP of <90, 90‐119, 120‐149, 150‐179, 180‐209, and ≥210 mm Hg, respectively.13 In our study, we showed a higher mortality rate in those with low and normal ED SBP. Low ED SBP levels in hypertensive patients may suggest a severe disease and therefore is associated with increased mortality. In contrast, elevated ED SBP was associated with lower mortality.
We have shown similar pattern of association between admission SBP and short‐term mortality to patients with heart failure and preserved ejection fraction.22 It is possible that elevated ED SBP indicates a preserved cardiac function with less severe disease and therefore is associated with low rate of in‐hospital mortality. Regardless of the mechanism, the results of our study suggest that in hypertensive patients, elevated SBP in the ED is associated with a favorable in‐hospital outcome.
Previous studies performed in older patients attending the ED for infection have shown higher mortality in the normal range SBP (110‐139 mm Hg).14, 25 Warmerdam et al studied 833 elderly patients admitted with suspected infection. In that study, SBP in the ranges of 101‐120 and 121‐139 mm Hg showed adjusted OR of 2.8 and 1.9 compared with the reference range of ≥140 mm Hg.14 This is in line with our study that showed that among elderly hypertensive patients attending the ED, normal SBP values (between 110 and 140 mm Hg) are associated with higher in‐hospital mortality compared to elevated SBP up to 200 mm Hg. Patel et al showed that patients with hypertensive urgency are commonly more hospitalized but the hospitalization is not associated with improved outcomes.26
Our study has several important limitations. This is a one‐center retrospective study, which relies on digitally stored data in a crowded ED. We have no records on the treatment given during hospitalization to lower BP. Therefore, we cannot comment on the therapeutic approach in these patients. The number of patients with SBP above 220 mm Hg was relatively small in our cohort, and further studies are needed to establish the results regarding that subgroup. As we do not have data on BP management in the ED or in hospital wards, no conclusion can be drawn on appropriate BP targets in hospitalized patients. High SBP seems to indicate relatively preserved cardiovascular function, but the association with lower in‐hospital mortality may be partially due to better BP‐lowering treatment. The average age in our study was 75.6 years, which reflects the age of hospitalized hypertensive patients; therefore, we cannot generalize our results to young patients.
In conclusion, in hospitalized hypertensive patients, ED SBP measurements show a “hockey stick” pattern of association with in‐hospital mortality. SBP levels of 110‐139 mm Hg were associated with higher in‐hospital mortality in comparison with elevated SBP up to 200 mm Hg.
CONFLICT OF INTEREST
None.
AUTHOR'S CONTRIBUTION
Ehud Grossman is the guarantor of the integrity of the entire study. Eyal Klang, Shelly Soffer, Moni (Shimon) Shahar, Yiftach Barash, Sara Apter, Eli Konen, Eyal Zimlichman, and Ehud Grossman conceived and designed the study. Eyal Klang, Shelly Soffer, and Yiftach Barash contributed to literature research. Eyal Klang, Moni (Shimon) Shahar, Yiftach Barash, and Ehud Grossman contributed to experimental studies and analyzed the data. Eyal Klang and Moni (Shimon) Shahar performed statistical analysis. Eyal Klang, Shelly Soffer, and Ehud Grossman prepared the manuscript. Eyal Klang, Shelly Soffer, Moni (Shimon) Shahar, Yiftach Barash, Sara Apter, Eli Konen, Eyal Zimlichman, and Ehud Grossman edited the manuscript.
Supporting information
Klang E, Soffer S, Shimon Shahar M, et al. Association of normal systolic blood pressure in the emergency department with higher in‐hospital mortality among hypertensive patients. J Clin Hypertens. 2019;21:1841–1848. 10.1111/jch.13727
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