aCardioConnecticuof MediciUniversityMount SindiovasculaNew JerseyTropical MIcahn SchohCardiovasiCardiovasington, DiCenter, DeCenter, JeClinic, Rocmanuscript

Drs BaSee pa*CorreE-mail

0002-9149http://dx.do

Trends of Hospitalizations in the United States from 2000to 2012 of Patients >60 Years With Aortic Valve Disease

Apurva O. Badheka, MD, FACP, CCDSa, Vikas Singh, MDb, Nileshkumar J. Patel, MDc,Shilpkumar Arora, MDd, Nilay Patel, MDe, Badal Thakkar, MDf, Sunny Jhamnani, MDa,

Sadip Pant, MDg, Ankit Chothani, MDh, Conrad Macon, MDb, Sidakpal S. Panaich, MDi, Jay Patel, MDi,Sohilkumar Manvar, MDi, Chirag Savani, MDj, Parth Bhatt, MDf, Vinaykumar Panchal, MDf,

Neil Patel, MDk, Achint Patel, MDk, Darshan Patel, MDi, Sopan Lahewala, MDl,Abhishek Deshmukh, MDl, Tamam Mohamad, MDi, Abeel A. Mangi, MDa, Michael Cleman, MDa,

and John K. Forrest, MDa,*

In recent years, there has been an increased emphasis on the diagnosis and treatment of valvular

vasculat; bCardne, MiHospitai St Lr Divisi; fCardedicineol of Pcular Dcular Dstrict otroit, Mrsey Cihester,receivedheka,ge 140spondinaddres

/15/$ -i.org/1

heart disease and, inparticular, aortic stenosis. This has beendriven inpart by thedevelopment ofinnovative therapeutic options and by an aging patient population.We hypothesized an increasein the number of hospitalizations and the economic burden associated with aortic valve disease(AVD). Using Nationwide Inpatient Sample from 2000 to 2012, AVD-related hospitalizationswere identified using International Classification of Diseases, Ninth Revision, Clinical Modifi-cation, code 424.1, as the principal discharge diagnosis. Overall AVD hospitalizations increasedby 59% from2000 to 2012.This increasewasmost significant in patients>80 years and thosewithhigher burden of co-morbidities. The most frequent coexisting conditions were hypertension,heart failure, renal failure, anemia, and diabetes. Overall inhospital mortality of patients hospi-talized for AVD was 3.8%, which significantly decreased from 4.5% in 2000 to 3.5% in 2012(p <0.001). The largest decrease in mortality was seen in the subgroup of patients who had heartfailure (62%reduction),higherburdenof co-morbidities (58%reduction), andwhowere>80years(53% reduction). There was a substantial increase in the cost of hospitalization in the last decadefrom $31,909 to $38,172 (p <0.001). The total annual cost for AVD hospitalization in the UnitedStates increased from $1.3 billion in 2001 to $2.1 billion in 2011 and is expected to increase tonearly 3 billion by 2020. The last decade has witnessed a significant increase in hospitalizationsfor AVD in theUnited States. The associated decrease in inhospital mortality and increase in thecost of hospitalization have considerably increased the economic burden on the public healthsystem. � 2015 Elsevier Inc. All rights reserved. (Am J Cardiol 2015;116:132e141)

Valvular heart disease is a major public health burden thatincreases with advancing age.1,2 Aortic valvular heart disease(AVD) in particular coexists with other more prevalent car-diovascular conditions, such as coronary artery disease, heart

r Division, Yale School of Medicine, New Haven,iovascular Division, University of Miami Miller Schoolami, Florida; cCardiovascular Division, Staten Islandal, Staten Island, New York; dCardiovascular Division,uke’s Roosevelt Hospital, New York, New York; eCar-on, Saint Peter’s University Hospital, New Brunswick,iovascular Division, Tulane School of Public Health and, New Orleans, Los Angeles; gCardiovascular Division,ublic Health at Mount Sinai, New York, New York;ivision, University of Louisville, Louisville, Kentucky;ivision, MedStar Washington Hospital Center, Wash-f Columbia; jCardiovascular Division, Detroit Medicalichigan; kCardiovascular Division, Jersey City Medicalty, New Jersey; and lCardiovascular Division, MayoMinnesota. Manuscript received March 3, 2015; revisedd and accepted March 26, 2015.Singh, and NJ Patel contributed equally to this study.for disclosure information.g author: Tel: (203) 785-4129; fax: (203) 483-8314.s: apurva_badheka@yahoo.com (J.K. Forrest).

see front matter � 2015 Elsevier Inc. All rights reserved.0.1016/j.amjcard.2015.03.053

failure, and hypertension, and patients often require inter-vention. AVD consists of primarily aortic stenosis and to alesser extent aortic insufficiency and mixed aortic valvediseases.3 Until recently, surgical aortic valve replacementwas the only proved therapy for the treatment of severesymptomatic aortic stenosis. For the past decade, innovationsin transcatheter valve technology have revolutionized themanagement of valvular heart disease in high- and extreme-risk patient populations.4,5 With the availability of moretreatment options, an aging population, and the incrementalcost of hospitalizations, the economic burden associated withAVD is of growing significance. Currently, there is paucityof data on AVD hospitalization trends on a national scale.6

The present study was designed to perform an evaluationof the temporal trends in AVD-related hospitalizations in theUnited States. We also assessed the overall burden of AVDin terms of inhospital mortality, co-morbid conditions, lengthof hospital stay, and cost of care during the hospitalization.

Methods

Data from the year 2000 to 2012 were obtained fromthe Nationwide Inpatient Sample (NIS). NIS is a part of afamily of databases developed for the Healthcare Cost and

www.ajconline.org

Figure 1. Trend of number of hospitalizations in US adults (age �60 years)for nonrheumatic AV disorders.

Valvular Heart Disease/AVD Hospitalization Trends 133

Utilization Project and is sponsored by the Agency forHealthcare Research and Quality. It is the largest availabledatabase of hospital inpatient stays in the United States thatincludes data on approximately 7 to 8 million dischargeseach year. Data from the NIS have previously been used toidentify, track, and analyze national trends in health careuse, patterns of major procedures, access, disparity ofcare, trends in hospitalizations, charges, quality, and out-comes.7e12 Each individual hospitalization in this databaseis de-identified and maintained as a unique entry with 1primary discharge diagnosis and <24 secondary diagnosesalong with <15 procedural codes during that hospitaliza-tion. To maintain the external validity, database is comparedwith the following data sources: the American HospitalAssociation Annual Survey Database, the National HospitalDischarge Survey from the National Center for HealthStatistics, and the MedPAR inpatient data from the Centersfor Medicare and Medicaid Services.13

We analyzed data from NIS from 2000 to 2012 using theInternational Classification of Diseases, Ninth Revision,Clinical Modification (ICD-9-CM) codes 424.1 forNon-Rheumatic Aortic Valve Disorders in the primarydischarge diagnosis. Only subjects >60 years wereincluded. The observations with missing information, suchas age, gender, admission or discharge date, and mortalitywere excluded. Admissions related to trauma were alsoexcluded. Both patient- and hospital-level variables wereincluded in the baseline characteristics of the study popu-lation for assessment of potential confounders. We definedseverity of co-morbid conditions using Deyo modificationof Charlson co-morbidity index (CCI).14 This index con-tains 17 co-morbid conditions with differential weights. Thescore ranges from 0 to 33, with higher scores correspondingto greater burden of co-morbid diseases (SupplementaryTable 1). Facilities were considered to be teaching hospi-tals if they had an American Medical Associationeapprovedresidency program, were a member of the Council ofTeaching Hospitals, or had a full-time equivalent intern andresident-to-patient ratio of �0.25. To calculate the estimatedcost of hospitalizations, the NIS data were merged with cost-to-charge ratios available from the Healthcare Cost andUtilization Project. We estimated the cost of each inpatientstay by multiplying the total hospital charge with the cost-to-charge ratio. Adjusted cost for each year was calculated

in terms of the 2011 cost after adjusting for inflationaccording to the latest consumer price index data releasedby the US government on January16, 2013.15 This enabledus to standardize the costs over the study period. Similarmethodology has been used in previous studies.10 Totalannual cost was calculated by multiplying mean cost of careper year with total number of cases for that year. Expo-nential trend line was used to illustrate the trend in total costfrom 2001 to 2011 (R2 ¼ 0.87). Cost projection for 2020was made assuming a similar increase in cost for AVDhospitalization over the next decade.

Stata IC 11.0 (Stata-Corp., College Station, Texas) andSAS 9.4 (SAS Institute Inc., Cary, North Carolina) wereused for analyses, which accounted for the complex surveydesign and clustering. Because NIS represents a 20%stratified random sample of US hospitals, analyses wereperformed using hospital-level discharge weights providedby the NIS to obtain national estimates of AVD hospitali-zations. For categorical variables like annual change inAVD hospitalization rate and inhospital mortality, thechi-square test of trend for proportions was used using theCochrane Armitage test16 through the “ptrend” command inStata. For continuous variables like cost of hospitalization,nonparametric test for trend by Cuzick17 (which is similar tothe Wilcoxon rank-sum test) using the “nptrend” commandin Stata was used. Differences between categorical variableswere tested using the chi-square test, and differences be-tween continuous variables were tested using the student’st test. p Value <0.05 was considered significant.

Results

A total of 113,847 hospitalizations with AVD as theprimary discharge diagnosis (weighted n ¼ 561,880) werereported in the United States from 2000 to 2012 in patients>60 years. The number of hospitalizations progressivelyincreased from 7,213 in 2000 to 11,531 in 2012 (p <0.001;Figure 1). The mean age of hospitalized patients increasedfrom 75.6 to 76.9 years. Patient characteristics have beensummarized in Table 1. Hospitalized patients with AVDwere predominantly non-Hispanic whites (69%) and were>70 years (76%). Overall, there were more hospitalizationsin men than women (55% vs 45%), and the difference inmale versus female gender ratio increased from 54% vs 46%in 2000 to 56% vs 44% in 2012 (Figure 2). The admissionrate in patients >80 years significantly increased from 32%in 2000 to 42% in 2012 (p <0.001). Admissions for patientswith higher co-morbidities (CCI �2) doubled from 25% in2000 to 50% in 2012 (Figure 3). The most frequent coex-isting conditions in these patients were hypertension (58%),heart failure (35%), renal failure and anemia (26% each),diabetes (24%), and chronic pulmonary disease (18%). Mosthospitalizations for AVD (82%) were associated withMedicare as the primary payer. In terms of the geographicdistribution of admissions, the hospitals in the South (29%)constituted the highest percentage of hospitalizations relatedto AVD, followed by Northeast (26%), Midwest (22%), andWest (20%). Overall inhospital mortality of patients hospi-talized for AVD was 3.8%, which significantly decreasedfrom 4.5% in 2000 to 3.5% in 2012 (p <0.001; Figure 4).The largest decrease in mortality was seen in the subgroup

Table 1Hospitalization for aortic valve disorders in US from 2000-2012 (ICD-9 code 424.1)

DemographicVariables

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Total P-valuefor Trend

Total No. ofObservations(>60 yrs age) withAV Disorders

7,213 7,905 7,830 7,881 7,696 7,546 8,267 7,931 8,950 10,539 8,895 11,663 11,531 113,847 <0.001

Age (years)60-69 23.4% 22.1% 23.1% 24.3% 24.0% 24.4% 24.0% 24.4% 24.1% 25.0% 24.9% 24.2% 23.4% 24.0% <0.00170-79 44.3% 44.5% 43.8% 41.1% 40.9% 40.6% 41.7% 39.0% 37.2% 38.0% 35.9% 35.1% 34.6% 39.3% <0.001>80 32.3% 33.4% 33.1% 34.6% 35.1% 35.1% 34.3% 36.6% 38.7% 37.0% 39.2% 40.8% 42.1% 36.7% <0.001

Male 53.6% 52.8% 53.6% 53.9% 54.7% 55.4% 54.6% 56.4% 55.5% 56.7% 56.3% 55.4% 56.0% 55.1% <0.001Female 46.4% 47.2% 46.4% 46.1% 45.3% 44.6% 45.4% 43.6% 44.5% 43.3% 43.7% 44.6% 44.0% 44.9% <0.001Non-hispanic Whites 69.0% 65.5% 60.6% 62.3% 64.9% 64.1% 65.3% 66.6% 69.7% 68.6% 74.7% 77.6% 79.1% 69.0% <0.001Others 9.0% 10.1% 10.0% 10.7% 9.4% 9.7% 10.4% 12.0% 11.8% 12.3% 12.8% 14.2% 14.9% 11.6% <0.001Missing 22.1% 24.4% 29.4% 27.0% 25.7% 26.3% 24.2% 21.4% 18.5% 19.1% 12.5% 8.2% 6.0% 19.4% <0.001AHRQ

Comorbidities*Charlson/ Deyo

ComorbidityIndex†

0 37.9% 36.3% 35.0% 34.1% 33.2% 31.6% 31.0% 28.3% 28.1% 27.6% 25.2% 23.2% 21.6% 29.6% <0.0011 36.7% 37.7% 37.1% 36.8% 37.3% 37.0% 33.8% 32.2% 32.6% 31.0% 31.6% 28.3% 28.1% 33.4% <0.001More than or equal

to 225.3% 26.0% 27.9% 29.1% 29.5% 31.4% 35.2% 39.6% 39.3% 41.4% 43.2% 48.5% 50.4% 37.1% <0.001

Obesity . . 5.0% 5.5% 6.9% 7.2% 7.9% 8.7% 12.1% 11.8% 12.3% 15.0% 15.9% 9.0% <0.001Hypertension . . 49.9% 53.1% 60.1% 62.7% 65.6% 65.6% 69.6% 71.0% 71.4% 74.6% 77.3% 57.7% <0.001Diabetes Mellitus . . 20.3% 20.6% 24.2% 25.0% 26.1% 27.9% 28.9% 29.5% 31.1% 31.7% 33.6% 24.0% <0.001Congestive Heart

Failure (AHRQcoded co-morbidity)

. . 1.5% 1.2% 1.3% 1.1% 1.1% 1.1% 1.0% 1.2% 1.1% 1.1% 0.8% 1.0% <0.001

History of ChronicPulmonaryDisease

. . 18.1% 18.4% 19.5% 21.4% 22.3% 21.8% 20.9% 21.0% 20.0% 22.6% 24.2% 18.3% <0.001

Peripheral VascularDisease

. . 10.1% 10.5% 13.1% 12.3% 13.4% 14.9% 16.2% 17.3% 15.3% 18.7% 19.9% 13.1% <0.001

Fluid-electrolyteabnormalities &Renal Failure

. . 15.4% 17.0% 17.8% 21.6% 27.9% 31.0% 32.7% 35.2% 34.7% 42.8% 43.3% 26.3% <0.001

Neurologicaldisorder orparalysis

. . 5.0% 3.7% 4.4% 4.6% 4.6% 5.5% 6.0% 6.0% 6.3% 6.7% 7.0% 4.8% <0.001

Anemia orcoagulopathy

. . 17.7% 19.7% 21.8% 25.7% 26.7% 29.2% 31.5% 33.3% 31.9% 39.9% 40.3% 25.9% <0.001

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Solid Tumors orMetastaticCancers orLymphoma

. . 9.7% 2.1% 2.5% 2.3% 2.3% 2.6% 2.2% 2.4% 2.6% 2.8% 2.8% 2.6% <0.001

Depression,Psychosis, orSubstance Abuse

. . 3.3% 4.3% 4.3% 3.9% 5.2% 6.0% 7.1% 7.0% 7.4% 8.3% 8.9% 5.4% <0.001

Liver Disease . . 0.7% 0.8% 0.7% 1.1% 0.8% 1.0% 1.1% 1.2% 1.0% 1.4% 1.5% 0.9% <0.001Co-morbidities

according toICD-9 code

Acute Heart Failure 0.0% 0.0% 0.1% 0.2% 0.4% 0.3% 0.3% 1.1% 6.2% 7.3% 9.5% 11.9% 14.0% 4.5% <0.001Heart Failure other

than Acute HeartFailure

30.3% 31.7% 32.3% 34.0% 33.2% 33.0% 32.5% 32.9% 26.9% 25.6% 26.3% 27.3% 28.4% 30.1% <0.001

Heart Failure(Total)

30.3% 31.7% 32.4% 34.2% 33.6% 33.3% 32.8% 34.0% 33.0% 32.9% 35.8% 39.1% 42.4% 34.5% <0.001

Acute MyocardialInfarction

2.4% 2.4% 2.2% 2.7% 2.6% 2.4% 2.0% 2.3% 2.4% 2.6% 3.1% 2.9% 2.9% 2.6% <0.001

Median HouseholdIncomeCategory forpatient’s Zipcodez

1. 0-25th percentile 4.9% 4.4% 3.4% 21.0% 20.0% 19.7% 19.1% 19.0% 20.0% 20.7% 20.8% 20.6% 22.1% 17.1% <0.0012. 26-50th

percentile26.4% 20.1% 17.1% 25.1% 25.5% 23.5% 24.5% 23.1% 27.5% 25.7% 26.7% 23.5% 24.1% 24.1% <0.001

3. 51-75thpercentile

27.9% 24.6% 23.7% 26.9% 23.5% 27.5% 25.1% 25.4% 24.3% 24.9% 26.2% 26.6% 25.2% 25.5% 0.867

4. 76-100thpercentile

39.1% 49.6% 53.4% 25.2% 28.6% 27.6% 29.3% 30.0% 26.7% 26.2% 24.3% 27.5% 27.0% 31.3% <0.001

Primary PayerMedicare 79.8% 81.5% 82.3% 83.7% 80.9% 81.8% 82.6% 81.2% 80.6% 81.3% 81.0% 83.3% 84.0% 81.9% <0.001Medicaid 2.0% 1.8% 1.4% 1.7% 1.5% 1.9% 1.3% 1.4% 1.5% 1.5% 2.0% 1.2% 1.3% 1.6% <0.001Private including

HMOs & PPOs16.2% 14.5% 14.3% 12.6% 15.6% 14.4% 14.3% 15.4% 15.6% 14.9% 14.6% 13.6% 12.5% 14.4% <0.001

Other/Self-pay 1.8% 2.0% 2.0% 1.9% 1.9% 1.9% 1.7% 2.0% 2.3% 2.1% 2.3% 1.7% 2.0% 2.0% 0.03Hospital

CharacteristicsBed size of Hospital

depending onLocation &Teaching Status

Small 7.7% 5.9% 6.8% 7.3% 8.3% 4.8% 9.2% 7.8% 8.1% 7.7% 9.3% 7.5% 7.9% 7.6% <0.001Medium 20.9% 15.9% 17.8% 21.5% 18.9% 21.2% 20.0% 21.4% 18.3% 15.5% 15.7% 18.0% 19.3% 18.6% <0.001Large 71.4% 78.2% 75.4% 71.2% 72.8% 74.1% 70.8% 70.7% 73.6% 74.9% 73.7% 74.1% 72.8% 73.4% 0.799

(continued)

Valvular

Heart

Disease/A

VD

Hospitalization

Trends

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Table 1(continued )

DemographicVariables

2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Total P-valuefor Trend

Hospital Location &Teaching Status

Rural 5.2% 5.7% 5.3% 6.0% 5.4% 4.0% 4.0% 5.2% 5.4% 5.2% 6.6% 3.4% 4.3% 5.0% <0.001Urban Non-teaching 29.8% 33.1% 34.6% 33.6% 33.1% 37.8% 37.8% 32.5% 38.0% 31.0% 33.6% 28.3% 27.9% 33.0% <0.001Urban Teaching 65.0% 61.2% 60.1% 60.4% 61.5% 58.2% 58.2% 62.3% 56.6% 63.9% 59.8% 68.3% 67.8% 62.0% <0.001

Hospital RegionNortheast 28.8% 25.4% 27.8% 22.8% 26.6% 24.8% 23.3% 27.3% 24.6% 23.3% 27.1% 27.4% 24.5% 25.6% <0.001Midwest 23.3% 19.9% 18.0% 21.7% 21.9% 22.4% 20.9% 18.7% 23.2% 26.0% 23.8% 18.8% 23.4% 21.8% <0.001South 30.7% 31.0% 27.8% 28.6% 28.5% 26.6% 29.3% 26.2% 28.5% 26.3% 27.3% 29.4% 32.6% 28.8% 0.659West 17.1% 17.9% 20.5% 20.8% 23.0% 26.2% 20.2% 21.1% 18.2% 19.5% 16.5% 20.0% 19.6% 19.9% <0.001

Admission TypeEmergency/Urgent 39.6% 38.2% 38.1% 38.2% 37.7% 36.8% 38.9% 36.5% 39.0% 38.0% 36.1% 35.1% . 33.7% <0.001Elective 50.1% 50.5% 49.8% 47.4% 50.4% 44.6% 50.0% 48.5% 51.9% 51.4% 56.7% 53.1% . 45.4% <0.001

Admission DayWeekdays 90.9% 91.4% 90.8% 90.5% 90.6% 92.0% 92.4% 91.3% 91.0% 91.7% 91.9% 92.2% 92.2% 91.5% <0.001Weekends 9.1% 8.6% 9.2% 9.5% 9.4% 8.0% 7.6% 8.7% 9.0% 8.4% 8.1% 7.8% 7.8% 8.5% <0.001

DispositionHome 50.7% 48.0% 49.0% 48.0% 43.5% 40.8% 40.7% 36.8% 36.9% 40.4% 35.9% 35.1% 36.6% 41.1% <0.001Transfer to

Short-termHospital/otherfacilities/HomeHealth Care

44.5% 47.3% 46.6% 46.8% 51.9% 55.1% 55.4% 59.3% 58.5% 56.1% 60.6% 61.3% 59.8% 54.7% <0.001

In HospitalMortality (diedin hospital)

4.5% 4.5% 3.9% 4.6% 4.3% 3.8% 3.7% 3.6% 4.3% 3.2% 3.3% 3.4% 3.5% 3.8% <0.001

Adjusted Cost toCharge ($)(Mean,Std Error)

. 31,909 32,989 34,595 35,210 37,897 36,369 38,080 35,365 36,453 38,052 38,172 . 36,090

Length of Stay(Mean, StdError)(days)

8.4 8.3 8.3 8.3 8.2 8.3 8.3 8.4 8.0 8.0 7.8 8.1 7.8 8.1

AHRQ ¼ Agency for Healthcare Research and Quality; AMA ¼ Against Medical Advice; HMO ¼ Health Maintenance Organization; ICD-9 ¼ International Classification of Disease; PPO ¼ PreferredProvider Organization.* Variables are AHRQ comorbidity measures.† Charlson/Deyo comorbidity index was calculated as per Deyo classification.z This represents a quartile classification of the estimated median household income of residents in the patient’s ZIP Code. These values are derived from ZIP Code-demographic data obtained from Claritas.

The quartiles are identified by values of 1 to 4, indicating the poorest to wealthiest populations. Because these estimates are updated annually, the value ranges vary by year. http://www.hcupus.ahrq.gov/db/vars/zipinc_qrtl/nisnote.jsp.

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Figure 3. Trend of mean Charlson score in US adults (age �60 years)hospitalized with nonrheumatic AV disorders.

Figure 2. Trend of gender distribution of US adults (age �60 years) hos-pitalized for nonrheumatic AV disorders.

Figure 4. Trend of mortality in US adults (age �60 years) hospitalized fornonrheumatic AV disorders.

Valvular Heart Disease/AVD Hospitalization Trends 137

of patients who had heart failure (62% reduction), had CCI>2 (58% reduction), and who were >80 years (53%reduction) (Table 2). Forty-one percent of the patients weredischarged to home, whereas 55% were transferred toanother facility (short- or long-term nursing homes orassisted facilities). There was a noticeable increase in thetrend for disposition to another facility, 45% in 2000 to 60%in 2012 (p <0.001; Figure 5). The length of hospital stay for

this patient population decreased from 8.4 days in 2000 to7.8 days in 2012 (p <0.001) and was associated with asubstantial increase in cost of hospitalization in the lastdecade from $31,909 to $38,172 (p <0.001; Figure 6). Thisrepresents an absolute increment in annual national costfrom an approximate $1.28 billion in 2001 to $2.13 billionin 2011. The total annual cost of AVD hospitalizationincreased exponentially from 2001 to 2011. Assuming asimilar increase in cost of care for AVD-related hospitali-zation, the total cost for AVD hospitalization is expected toincrease to nearly $3 billion by 2020 (Figure 7).

Discussion

This large study provides insights into trends of AVDhospitalizations for a 13-year period in the United States.Our findings indicate a significant rising trend in hospitali-zations for AVD nationwide during the study period. Therising incidence of admissions was most notable in patients>80 years and those with higher co-morbidities (CCI >2).This rising hospitalization rate for AVD in our analysis wasassociated with significant reduction in mortality, which wasmost evident in patients >80 years, with heart failure andCCI >2. The total length of hospital stay has decreased;however, the cost of care during hospitalization has signif-icantly increased, after adjusting for inflation. We alsodemonstrate an increasing trend of disposition of patients toanother facility and the need for home health care thatsuggests further increases in the economic burden on healthcare.

Aortic stenosis, the most common type of valvular heartdisease in Western countries, occurs because of a degener-ative process of the valve and is not often considered amajor public health burden.3 The findings of our studysuggest that the contribution of AVD to the economic healthburden is of growing significance. The increase in AVDadmission rates noted in our study is likely multifactorialbecause of the aging of general population, improveddiagnostic methods, innovative treatment options, and lowerthreshold for patients to seek medical care. A retrospectiveepidemiologic study conducted in Scotland on 19,733 adulthospitalizations for noncongenital AVD from 1997 to 2005also indicated a striking rising trend in hospitalizations.6

They noted aortic stenosis to have the most pronouncedincrease in hospital admissions and to be associated with thehighest mortality during the study period.6 In a studyincluding residents of Olmsted County with clinicallydiagnosed valvular heart disease (n ¼ 1,505), the prevalenceof aortic stenosis (n ¼ 547) was nearly twice that of aorticregurgitation (n ¼ 282).1 This gap further widened withincreasing age such that in patients >75 years, the preva-lence of AS and AI was 4.6% (n ¼ 308) and 1.7%(n ¼ 115), respectively.1

We noted that the age distribution of hospitalized patientshas changed significantly such that an increasing number ofpatients admitted for AVD toward the end of the study periodwere>80 years (42% in 2012). In addition to being older, thehospitalized patients had many more co-morbidities, whichwas evident from the rising Charlson score, CCI >2 in 50%of the patients in 2012. Hypertension and heart failure werethe 2 most common co-morbidities in patients hospitalized

Table 2In-hospital mortality (>60 yrs of age) for aortic valve disorders in US from 2000-2012 (ICD-9 code 424.1)

Year 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 Relative Change P-value for Trend

Overall 4.53% 4.5% 3.86% 4.64% 4.29% 3.77% 3.74% 3.62% 4.32% 3.2% 3.34% 3.41% 3.46% -30.92% <0.001Age(years)60-69 2.56% 2.59% 2.03% 3.14% 2.73% 1.99% 2.32% 2.55% 2.37% 1.76% 2.3% 1.7% 2.26% -13.27% <0.00170-79 4.03% 4.43% 3.51% 4.24% 4.31% 3.58% 3.63% 3.02% 3.98% 3.08% 3.33% 3.22% 3.19% -26.33% <0.001>80 6.65% 5.86% 5.62% 6.17% 5.32% 5.23% 4.87% 4.97% 5.85% 4.29% 4% 4.59% 4.35% -52.87% <0.001Male 3.83% 3.81% 3.34% 4.28% 3.67% 3.5% 3.33% 3.33% 3.91% 3.18% 2.94% 3.16% 3.41% -12.32% <0.001Female 5.33% 5.28% 4.47% 5.06% 5.03% 4.11% 4.23% 4% 4.83% 3.22% 3.85% 3.73% 3.53% -50.99% <0.001Non-hispanic Whites 4.45% 4.61% 3.85% 4.34% 4.22% 3.84% 3.74% 3.44% 4.4% 3.15% 3.3% 3.42% 3.39% -31.27% <0.001Others 4.5% 5.72% 4.08% 4.24% 5.32% 2.98% 3.29% 3.76% 4.17% 2.4% 3.42% 3.78% 3.67% -22.62% <0.001Missing 4.8% 3.7% 3.83% 5.49% 4.07% 3.88% 3.92% 4.09% 4.1% 3.88% 3.46% 2.73% 3.88% -23.71% <0.001

AHRQ Comorbidities*Charlson/ Deyo

Comorbidity Index†

0 1.74% 2.13% 2.25% 2.17% 2.15% 2.21% 1.58% 2% 3.2% 1.85% 1.71% 1.87% 1.37% -27.01% <0.0011 5.1% 5.19% 4.24% 5.05% 4.98% 3.48% 3.63% 3.58% 3.81% 2.51% 2.84% 2.59% 2.32% -119.83% 0.005More than or equal to 2 7.89% 6.81% 5.4% 7.02% 5.8% 5.69% 5.75% 4.82% 5.54% 4.61% 4.65% 4.64% 4.99% -58.12% <0.001

Hypertension . . 2.05% 3.17% 3.12% 2.6% 2.65% 2.69% 3.44% 2.45% 2.47% 2.82% 3.05% 32.79% 0.064Diabetes Mellitus . . 3.22% 4.34% 3.74% 3% 2.92% 3.18% 3.02% 3.07% 3.25% 3.2% 3.48% 7.47% 0.107Congestive Heart Failure

(AHRQ codedco-morbidity)

. . 18.34% 23.05% 22.6% 21.73% 26.91% 24.67% 27.32% 21.02% 18.67% 18.42% 23.4% 21.62% 0.547

Co-morbidites accordingto ICD-9 code

Acute Heart Failure . . 0.0% 18.18% 6.48% 8.29% 6.59% 4.11% 5.87% 6.09% 4.96% 6.39% 5.65% -221.77% 0.24Heart Failure other than

Acute heart failure8.25% 7.86% 6.07% 8.12% 7.04% 6.23% 6.6% 5.78% 6.58% 5.17% 5.44% 4.65% 4.82% -71.16% <0.001

Heart Failure (total) 8.25% 7.86% 6.06% 8.18% 7.04% 6.24% 6.6% 5.72% 6.44% 5.38% 5.31% 5.18% 5.09% -62.08% <0.001Acute Myocardial

Infarction17.78% 17.17% 13.89% 19.24% 21.13% 14.61% 19.55% 10.87% 14.22% 12.37% 12.29% 11.81% 14.54% -22.28% <0.001

Primary PayerMedicare 5% 4.74% 4.03% 4.77% 4.51% 3.89% 4.04% 3.73% 4.5% 3.32% 3.48% 3.55% 3.59% 39.28% <0.001Medicaid 2.75% 5.5% 8.05% 4.69% 5.66% 4.22% 0.0% 4.91% 2.18% 3.79% 1.79% 2.05% 4.64% 40.73% <0.001Private including

HMOs & PPOs2.83% 2.93% 2.62% 3.29% 2.84% 2.99% 2.08% 2.74% 3.08% 2.3% 2.49% 2.04% 2.01% 40.80% <0.001

Other/Self-pay 0.0% 1.53% 1.38% 8.46% 5.84% 1.54% 1.64% 2.76% 4.59% 1.68% 5.27% 3.99% 2.3% 33.48% <0.001Hospital CharacteristicsBed size of Hospital

depending onLocation & TeachingStatus

Small 5.91% 4.96% 4% 3.82% 5.16% 3.14% 4.9% 3.24% 4.85% 3.48% 4.3% 3.52% 4.17% -41.73% <0.001Medium 4.51% 4.6% 4.27% 4.03% 3.7% 3.83% 3.3% 3.74% 4.27% 3.41% 3.18% 3.43% 3.06% -47.39% <0.001Large 4.39% 4.45% 3.76% 4.91% 4.34% 3.79% 3.71% 3.63% 4.27% 3.16% 3.27% 3.36% 3.49% -25.79% <0.001

138The

American

Journalof

Cardiology

(www.ajconline.org)

HospitalLocation&

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3.73

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1.

Figure 5. Trend of disposition in US adults (age �60 years) hospitalized fornonrheumatic AV disorders.

Figure 6. Trend of adjusted cost in US adults (age �60 years) hospitalizedfor nonrheumatic AV disorders.

Valvular Heart Disease/AVD Hospitalization Trends 139

for AVD. There was an overall decrease in inhospital mor-tality in patients admitted for AVD during the study period.This reduction in mortality was seen in all age groups;however, it was most striking in patients >80 years (53%relative reduction). The increasing hospitalizations in pa-tients >60 years together with reduced inhospital mortalitymay be because of improved diagnostic tools, use of bettertechnology (imaging, monitoring devices, hemodynamicassist devices, etc.), increasing experience, awareness aboutthis patient population, improvement in existing treatment,and the success of novel minimally invasive therapeuticoptions which are now available for valvular conditions, suchas transcatheter aortic valve replacement for aortic stenosis,the most prevalent AVD.1,2,6

We noted a significant difference in the gender distri-bution of hospitalizations for AVD. More men than womenwere admitted for AVD throughout the study period, andthis gap increased slightly during the course of study. Pre-vious epidemiologic studies have not shown any differencebetween prevalence of valvular heart disease in men versuswomen; however, a trend toward higher prevalence of aorticstenosis in men has been suggested.1,6 The imbalance ofgender ratios in hospitalizations related to AVD in our studycould indicate a gender bias in referral patterns for diagnosisand treatment.

Figure 7. Trend in cost of care of aortic valve disease-related hospitalization in the United States from 2001 to 2011 and cost projection for 2020.

140 The American Journal of Cardiology (www.ajconline.org)

The mean length of hospital stay decreased during thecourse of the study period; however, there was a significantincrease in the cost of inhospital care. Increasing number ofhospitalizations, aging population, patient complexity withmultiple co-morbidities, and increasing disposition trend toanother facility are some of the factors that may have beenresponsible for increasing cost. These figures are alarmingas the number of subjects aged >80 years is expected toincrease from 11.4 million in 2008 and to 19.5 million in2030, which in turn will lead to an enormous increasedburden on the public health system and its associated costof care.18

The study limitations are inherent to the post hoc anal-ysis of an administrative database. Although administrativedatabases are increasingly used for clinical research, suchstudies are potentially susceptible to errors (underestima-tion of number of hospitalizations) arising from codinginaccuracies. The diagnosis of AVD and the presence ofco-morbidities were based on administrative codes. Wewere, therefore, unable to distinguish aortic stenosis, aorticinsufficiency, or mixed aortic valvular disorders. This is alimitation of the ICD-9 code and hopefully will be resolvedwith introduction of ICD-10 code. However, administrativecodes have been shown to be highly specific for cardio-vascular diagnoses and risk factors. The use of ICD-9codes to study trends of AVD has previously been vali-dated. We also lack information on severity of the valvulardisease that predicts mortality. The nature of the dataallowed us to only examine inhospital mortality; hence, thestudy did not have any long-term follow-up outcomes.While acknowledging these limitations, the present studyhas important strengths including a “real-world” largesample size and the absence of selection bias noted inprevious smaller studies.

Disclosures

None of the other authors have any disclosures relevantto the content of the manuscript.

Supplementary data

Supplementary data associated with this article can befound, in the online version, at http://dx.doi.org/10.1016/j.amjcard.2015.03.053.

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