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  CARDIOLOGY/ORIGINAL RESEARCH Subclinical Hypertensive Heart Disease in Black Patients WithElevated Blood Pressure in an Inner-City Emergency Department Phillip Levy, MD, MPH, Hong Ye, MS, Scott Compton, PhD, Robert Zalenski, MD, Timothy Byrnes, MD,John M. Flack, MD, MPH, Robert Welch, MD, MS From the Department of Emergency Medicine (Levy, Zalenski, Welch), the Division of Cardiology (Byrnes), the Department of Internal Medicine (Flack) and the Cardiovascular Institute (Levy, Flack, Welch), Wayne State University School of Medicine, Detroit, MI; the Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, MI (Ye); and the Department of Emergency Medicine, UMDNJ–New Jersey Medical School (Compton), Newark, NJ. Study objective:  We examine the point prevalence of subclinical hypertensive heart disease in a cohort of urbanemergency department (ED) patients with elevated blood pressure. Methods:  A convenience sample of hypertensive (blood pressure  140/90 mm Hg on 2 measurements)patients aged 35 years or older with no history of cardiac or renal disease who presented to a single urban EDand were asymptomatic from a cardiovascular perspective (ie, no symptoms of dyspnea or chest pain) wereenrolled. All patients underwent a standardized evaluation (including echocardiography), and subclinicalhypertensive heart disease was defined by the presence of one or more of the following criterion-basedelectrocardiographic findings: left-ventricular hypertrophy, systolic dysfunction, or diastolic dysfunction. Results:  A total of 161 patients were included. Mean age was 49.8 years (SD 8.3 years), 93.8% were black,and 51.6% were men. Nearly all (93.8%) had a history of hypertension, and many (68.3%) were receivingantihypertensive therapy at baseline. Mean systolic and diastolic blood pressures were 183.9 mm Hg (SD 25.1mm Hg) and 109.5 mm Hg (SD 14.4 mm Hg), respectively. Subclinical hypertensive heart disease was found in146 patients (90.7%; 95% confidence interval [CI] 85.2% to 94.3%), with most (n  131) displaying evidence of diastolic dysfunction (89.7%; 95% CI 83.7% to 93.7%). Left-ventricular hypertrophy was also common (n  89;61.0%; 95% CI 52.9% to 68.5%) and was often (but not exclusively) present in those with diastolic fillingabnormalities (n  75; 57.3%; 95% CI 48.7% to 65.4%). Conclusion:  In our largely black cohort of ED patients with elevated blood pressure, subclinical hypertensiveheart disease was highly prevalent, suggesting the need for coordinated efforts to reduce cardiac consequencesof hypertension in such inner-city communities. [Ann Emerg Med. 2012;60:467-474.]Please see page 468 for the Editor’s Capsule Summary of this article. A  feedback  survey is available with each research article published on the Web at www.annemergmed.com.A  podcast  for this article is available at www.annemergmed.com.0196-0644/$-see front matterCopyright  ©  2012 by the American College of Emergency Physicians.http://dx.doi.org/10.1016/j.annemergmed.2012.03.030 SEE EDITORIAL, P. 475. INTRODUCTION Background  Hypertension is commonplace in the United States, affecting more than 76 million individuals older than 20 years. 1 Theburden of hypertension is particularly prominent among blacks, who experience a higher disease prevalence and, especially formen, poorer overall blood pressure control than their white andHispanic counterparts. 1,2  As a result, blacks are at tremendousrisk for pressure-related consequences of hypertension,particularly premature onset of structural cardiac damage andfunctional impairment. 3,4 Importance Unfortunately for many, such underlying hypertensive heartdisease is unlikely to be detected until advanced, clinically apparent manifestations are present. 5-8  With appropriate bloodpressure reduction, however, the deleterious effects of subclinical cardiac disease can be mitigated, symptom onset(especially heart failure) can be forestalled, and future adverseevents can be prevented. 9-11 Early identification of subclinicalcardiac disease has thus emerged as an important aspect of secondary cardiovascular disease prevention. 12 Despite the compelling benefits of directed intervention forpatients with subclinical cardiac disease, the utility of routinescreening in asymptomatic hypertensive patients remainscontroversial. 12-15 This may be attributable, in part, to uncertainty  Volume  , .  :  October    Annals  of    Emergency Medicine  467  about the prevalence of subclinical hypertensive heart disease, which, depending on operational definitions and the populationstudied, can vary from 0.9% to 50%. 4,16-21 Such data, however, were compiled almost exclusively with community-based sampling methods and may not accurately depict the level of risk that existsfor the many millions of patients who present with moderate orseverely elevated blood pressure each year to emergency departments (EDs) across the United States. 22,23 Of particularconcern, they may underestimate the prevalence of subclinicalhypertensive heart disease in inner-city blacks, an especially high-risk subset who, for lack of an alternative, rely on the ED fordetection or ongoing management of primary care amenableconditions such as hypertension. 24-27 Goals of This Investigation Because hypertension contributes more than any other factor toracial differences in cardiovascular disease survival, 28 much can begained through enhanced understanding of subclinical hypertensiveheart disease (a potentially modifiable preclinical disease state) inat-risk hypertensive patients. Accordingly, the objective of thisstudy was to estimate the point prevalence of echocardiographically defined subclinical hypertensive heart disease in a cohort of predominantly black, inner-city ED patients with asymptomaticyet profoundly elevated blood pressure. MATERIALS AND METHODS Study Design and Setting  This was designed as a prospective cross-sectional study of patients who presented to the ED of a single medical center(Detroit Receiving Hospital, Detroit, MI) between April 2006and July 2007 with elevated blood pressure. Detroit Receiving Hospital is a tertiary care facility operating within a large urbanenvironment and is affiliated with the Wayne State University School of Medicine. The hospital ED has a total annual censusof approximately 98,000 adult patients, the majority of whom(  85%) are black. Study approval was obtained from theHuman Investigations Committee of Wayne State University before patient recruitment. Selection of Participants The purpose of this study was to evaluate the point prevalenceof subclinical hypertensive heart disease in ED patients who hadelevated blood pressure but were asymptomatic from theperspective of potential acute or chronic end-organ cardiac damage. As such, we targeted enrollment of patients aged 35 years or older who met validated criteria for stage 1 or greater hypertension(blood pressure  140/90 mm Hg on initial ED triage vital signassessment and at repeated measurement 1 hour later, both of  which were obtained with an automated, adult-sized blood pressurecuff  27,29-31 ) and had neither a primary nor secondary presenting complaint potentially attributable to an acute hypertensiveemergency or underlying cardiac disease (ie, chest pain,palpitations, dyspnea, syncope, focal neurologic deficits, and alteredmental status). To avoid conflict with patient care needs and tominimize the potential influence of acute physiologic perturbationson echocardiographic findings, patients who required hospitaladmission for any reason were excluded from the study. Moreover,patients with a known cardiac condition (ie, heart failure, coronary artery disease, cardiomyopathy [dilated, idiopathic, orhypertrophic], or valvular heart disease), those at risk for heartdisease from a cause other than hypertension (ie, renal failure), andthose with previously documented evidence of abnormal cardiacstructure or function on echocardiography or other cardiovascularimaging study (ie, computed tomography, magnetic resonanceimaging, or cardiac catheterization), whether hypertensive in causeor not, were also excluded. Patients with diabetes mellitus, however, were eligible for inclusion.Screening was performed in the ED by dedicated researchpersonnel. Written informed consent was obtained frompatients who met eligibility criteria and were willing toparticipate. Our initial intent was to recruit 24 hours a day, 7days a week; however, we encountered difficulty in having patients return for study procedures once they were dischargedfrom the ED. To account for this, we adjusted our approach sothat the entire study protocol (described in greater detail in thefollowing section) could be completed in the ED at enrollment.To accommodate this change, recruitment had to becoordinated with the availability of key personnel (specifically,the study’s echocardiographic technician), limiting screening to“usual” business hours (Monday through Friday, 9  AM  to 4  PM ).Subjects included in the study cohort thus represent a convenience sample of ED patients.To evaluate for potential bias in our sample, we comparedpatients who were enrolled in the study with a consecutive series Editor’s Capsule Summary  What is already known on this topic  Emergency physicians treat many patients who havesuboptimally controlled hypertension. What question this study addressed   Whether patients with asymptomatic hypertensionhave subclinical heart disease. What this study adds to our knowledge  In a largely black 161-patient sample, the majority (91%; 95% confidence interval 85% to 94%) of patients with asymptomatic hypertension hadunderlying cardiac dysfunction, most commonly diastolic dysfunction. How this is relevant to clinical practice  The recognition that in some emergency departments most patients with asymptomatichypertension have underlying cardiac dysfunctionshould lead to improved vigilance in developing coordinated care pathways to prevent furtherdeterioration. Hypertension in the Emergency Department  Levy et al  468  Annals  of    Emergency Medicine Volume  , .  :  October    of ED patients treated for hypertension during a contemporaneous period. Patients included in this consecutiveseries (n  742) were culled by applying study eligibility criteria to a larger group identified by primary discharge diagnosis( International Classification of Diseases, Ninth Revision  code401.9—unspecified essential hypertension) with billing data.Once patients were enrolled, baseline data (demographics,medical and family history, and use of pharmaceutical agents) were collected by trained research assistants, ECG wasperformed, urine was collected for dipstick testing, and serumsamples were obtained for measurement of blood urea nitrogen,creatinine, and b-type natriuretic peptide (Biosite Incorporated,San Diego, CA). Echocardiograms were subsequently obtainedat the point of care in the ED by a single, certifiedechocardiographic technician using a Phillips iE333 ultrasoundmachine (Phillips Heathcare US, Andover, MA) with a 2.5-MHz cardiac transducer and interpreted by one of 2 board-certified cardiologists who were blinded to all demographic andhistorical information, as well as ECG, urine dipstick, bloodurea nitrogen, creatinine, and b-type natriuretic peptide data.Echocardiography in enrolled subjects was performed expressly for purposes of this study, and results were not used to informclinical management. Outcome Measures Subclinical hypertensive heart disease, the primary outcome of interest, was determined by demonstration of one or more of thefollowing externally validated 2-dimensional and Dopplerechocardiographic criteria  32,33 : left-ventricular hypertrophy,defined by left-ventricular mass indexed to height 2.7 greater than orequal to 46 g/m 2.7 for women or greater than or equal to 49 g/m 2.7 for men; left-ventricular systolic dysfunction determined by Simpson’s biplane method, defined by an ejection fraction less thanor equal to 50%; or left-ventricular diastolic dysfunction, definedby diastolic velocity measured at the medial mitral annulus by tissueDoppler imaging (e = ) less than 8 cm/second. Primary Data Analysis The primary purpose of this study was to provide a preciseestimate of the point prevalence of subclinical hypertensive heartdisease among asymptomatic, hypertensive ED patients. Toprovide a sufficient sample population for an a priori prevalenceestimate of 10% with a 95% confidence interval (CI) of 6.5% to13.5% (3.5%), screening of 254 patients was needed.Groupwise descriptive data were compiled, and proportionsor means and medians with corresponding measures of variance(SD and interquartile range, respectively) were calculated. All data were entered into a Microsoft Office 2007 Accessprogram (Microsoft, Bellevue, WA) and subsequently analyzed with SPSS (version 16.0; SPSS Inc, Chicago, IL). To ensuredata integrity, double entry was performed for all patientsincluded in the final analysis, with adjudication by the principalinvestigator (P.L.) of any variables with demonstrateddiscrepancy. RESULTS Two hundred patients were enrolled and echocardiograms were successfully obtained for 180 (90%). Despite contradictory self-report, 19 (10.6%) patients were found on subsequentcomprehensive chart review to have a history of heart failure orcoronary artery disease and were thus excluded, resulting in a final study cohort of 161 patients. A flow chart of study cohortderivation is provided in the Figure. Although enrollment fell short of our projected target,analysis of study echocardiograms revealed the presence of subclinical hypertensive heart disease in 146 patients, yielding a point prevalence that was far greater (90.7%; 95% CI 85.2% to94.3%) than our a priori estimate. The majority of patients withsubclinical hypertensive heart disease (Table 1) had diastolic dysfunction (n  131; 89.7%; 95% CI 83.7% to 93.7%), a finding that was associated with concurrent left-ventricularhypertrophy in most but not all patients (n  75; 57.3%; 95%CI 48.7% to 65.4%). Twenty-five individuals (15.5%; 95% CI10.7% to 21.9%) had evidence of systolic dysfunction with an Patients initially consented for participation in study n=200 Failed to return for outpatient echo n=20 Found to have prior documented history of cardiac disease n=19 Included in final study cohort n=161 Figure.  Flow chart outlining derivation of study cohort. Table 1.  Breakdown of subclinical hypertensive heart diseaseby left-ventricular dysfunction criterion in patients with andwithout left-ventricular hypertrophy. Left-VentricularDysfunctionLeft-VentricularHypertrophyTotal, No.(%)*Yes No None 12 0 12 (8.2)Diastolic dysfunction alone 60 49 109 (74.7)Systolic dysfunction alone 2 1 3 (2.1)Systolic and diastolicdysfunction15 7 22 (15.1) Total, No. (%) * 89 (61.0) 57 (39.0) 146 (100) *Percentage of patients with subclinical hypertensive heart disease (n  146). Levy et al   Hypertension in the Emergency Department Volume  , .  :  October    Annals  of    Emergency Medicine  469  Table 2.  Baseline data. VariableOverall,Subclinical HypertensiveHeart Disease,No Subclinical HypertensiveHeart Disease,n  161 n  146 n  15 Mean Age, y (SD) 49.8 (8.3) 50.0 (8.3) 47.3 (8.3) Sex, No. (%) Male 83 (51.6) 77 (52.7) 6 (40.0)Female 78 (48.4) 69 (47.3) 9 (60.0) Race, No. (%) Black 151 (93.8) 137 (93.8) 14 (93.3)White 6 (3.7) 6 (4.1) 0Body mass index, kg/m 2 (SD) 29.8 (7.1) 30.2 (7.0) 26.3 (6.7)Insured, No. (%) 93 (57.8) 86 (58.9) 7 (46.7) Reason for ED visit, No. (%) High blood pressure 37 (23.0) 33 (22.6) 4 (26.7)Headache 11 (6.8) 10 (6.9) 1 (6.7)Epistaxis 3 (1.9) 3 (2.1) 0Acute injury 13 (8.1) 12 (8.2) 1 (6.7)Chronic pain 19 (11.8) 16 (11.0) 3 (20.0)Acute infection 20 (12.4) 19 (13.0) 1 (6.7)GI or GU complaint 32 (20.0) 30 (20.6) 2 (13.3)Neurologic or psychiatric complaint 17 (10.6) 15 (10.3) 2 (13.3)Metabolic issue 10 (6.2) 9 (6.2) 1 (6.7) History of hypertension, No. (%)  151 (93.8) 137 (93.8) 14 (93.3)Receiving antihypertensive therapy, No. (%) 110 (68.3) 98 (67.1) 12 (80.0)Antihypertensive class, No. (%)ACEI or ARB 25 (15.5) 21 (14.4) 4 (26.7)  -Blocker 20 (12.4) 16 (11.0) 4 (26.7)Clonidine 30 (18.6) 30 (20.6) 0Diuretic 35 (21.7) 30 (20.6) 5 (33.3)Calcium-channel blocker 31 (19.3) 27 (18.5) 4 (26.7)Other 9 (5.6) 8 (5.5) 1 (6.7)Unknown 51 (31.7) 48 (32.9) 3 (20.0) History of diabetes, No. (%)  30 (18.6) 26 (17.8) 4 (26.7)Receiving diabetic medication, No. (%) 23 (14.3) 20 (13.7) 3 (20.0)Insulin 11 (6.8) 9 (6.2) 2 (13.3)Oral agents 12 (7.5) 11 (7.5) 1 (6.7)History of stroke, No. (%) 15 (9.3) 15 (10.3) 0 Other medications, No. (%) Statin 11 (6.8) 10 (6.9) 1 (6.7)Aspirin 24 (14.9) 22 (15.1) 2 (13.3)NSAID 22 (13.7) 18 (12.3) 4 (26.7) Social history, No. (%) Active cigarette smoker 78 (48.5) 72 (49.3) 6 (40.0)Drinks alcohol 76 (47.2) 67 (45.9) 9 (60.0)Uses cocaine 14 (8.7) 11 (7.5) 3 (20.0)Uses heroin 8 (5.0) 8 (5.0) 0Smokes marijuana 30 (18.6) 29 (19.9) 1 (6.7) Physical examination findings, No. (%) Elevated jugular venous pressure 1 (0.6) 1 (0.7) 0Lower extremity edema 6 (3.7) 6 (4.1) 0Ascites 1 (0.6) 1 (0.7) 0S 3  gallop 0 0 0Pulmonary rales 0 0 0 Initial vital signs, mean (SD) Systolic blood pressure, mm Hg 183.9 (25.1) 184.4 (25.3) 179.0 (23.0)Diastolic blood pressure, mm Hg 109.5 (14.4) 109.7 (14.4) 108.3 (15.3)Pulse rate, beats/min 85.1 (16.0) 84.6 (15.3) 89.9 (21.7) Repeated vital signs, mean (SD) Systolic blood pressure, mm Hg 175.1 (23.4) 174.9 (23.7) 177.7 (20.7)Diastolic blood pressure, mm Hg 105.1 (15.1) 104.6 (14.7) 110.1 (18.6)Pulse rate, beats/min 80.1 (14.4) 79.5 (14.1) 85.5 (17.2) Hypertension in the Emergency Department  Levy et al  470  Annals  of    Emergency Medicine Volume  , .  :  October  

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