AD

ULT

CA

RD

IAC

Impact of Functional Status on Survival AfterCoronary Artery Bypass Grafting in a VeteranPopulationRoberto Cervera, MD, Faisal G. Bakaeen, MD, Lorraine D. Cornwell, MD,Xing Li Wang, MD, PhD, Joseph S. Coselli, MD, Scott A. LeMaire, MD, andDanny Chu, MDDivision of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston; Division of

Cardiovascular Surgery, Texas Heart Institute at St. Luke’s Episcopal Hospital, Houston; and Division of Cardiothoracic Surgery,Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas

Background. Although functional impairment has beenshown to be an adverse outcome of frailty, little is knownof its effect on patients after cardiac operations. Weaimed to assess the effect of limited functional status onlong-term survival after coronary artery bypass grafting(CABG).

Methods. We reviewed prospectively gathered datafrom 1,503 consecutive patients who underwent isolatedCABG between 1997 and 2009. We compared the out-comes of 318 patients with limited functional status and1,185 patients without any functional impairment. Themean follow-up period was 65 months (range, 1 to 157months). We assessed the relationship between func-tional status impairment and long-term survival by Coxregression analysis adjusted for confounding factors.

Results. Functionally impaired patients were slightly

older (63 � 9 vs 62 � 8 years, p � 0.05) and had more risk

of Medicine, Michael E. DeBakey Veterans Affairs Medical Center, 2002Holcombe Blvd, OCL 112, Houston, TX 77030; e-mail: dchu@bcm.edu.

© 2012 by The Society of Thoracic SurgeonsPublished by Elsevier Inc

factors for adverse outcomes than patients who werefunctionally unimpaired. After adjustment for potentialconfounding variables by multivariate logistic regressionanalysis, preoperative limited functional status was notan independent predictor (odds ratio [95% confidenceinterval]) of 30-day mortality (1.4 [0.3 to 5.8], p � 0.67) ormajor adverse cardiac events (1.3 [0.5 to 3.3], p � 0.71), norwas it predictive of reduced long-term survival (10-yearhazard ratio 1.0 [0.7 to 1.4], p � 0.85).

Conclusions. Limited functional status was not anindependent risk factor for early postoperative compli-cations or death. Long-term survival in patients whosefunctional status was impaired before they underwentCABG was similar to that of patients who were function-ally independent.

(Ann Thorac Surg 2012;93:1950–5)

© 2012 by The Society of Thoracic Surgeons

Despite maximum medical therapy, many elderlypatients with cardiovascular disease remain se-

verely symptomatic. More than 25% of Americans aged80 years and older are functionally limited by cardiovas-cular disease [1]. Continuous advances in operative tech-niques, myocardial protection, and perioperative carehave led to a steady decline in cardiac surgical operativedeaths in older patients [2, 3]. As a result, more elderlypatients are being referred for coronary artery bypassgrafting (CABG) as a primary treatment for their coro-nary artery disease.

Advanced age is a well-accepted independent riskfactor for an adverse outcome in cardiac operations [4–6].Nonetheless, numerous series have shown that favorableoutcomes can be achieved in carefully selected elderlypatients who undergo cardiac operations [2, 7, 8]. Thereason may be that chronologic age does not reflect

Accepted for publication Feb 23, 2012.

Presented at the Fifty-eighth Annual Meeting of the Southern ThoracicSurgical Association, San Antonio, TX, Nov 9-12, 2011.

Address correspondence to Dr Chu, Texas Heart Institute/Baylor College

biologic age (ie, vigorousness or frailty) in all patients [9,10]. The concept of frailty has become increasingly im-portant, especially in geriatric medicine, for accuratelyassessing a patient’s biologic performance or functionalstatus [11, 12].

In 2010 Lee and colleagues [13] showed that frailpatients (as identified by the Katz frailty index) are at anincreased risk for perioperative death and prolongedinstitutional care after cardiac operations. More recently,Sündermann and colleagues [14] were able to show astatistically significant correlation between the Compre-hensive Assessment of Frailty (CAF) score, initially de-veloped by Dewey and colleagues in Medical City, Dal-las, and observed 30-day mortality rate among elderlypatients who underwent cardiac operations.

Impairment of physical activity or functional status isone of the many end results of frailty [15, 16]. Althoughimpairment of activities of daily living (ADL) has beenshown to adversely affect the outcomes of cancer patientsand elderly patients [17, 18], little is known of its long-term effect on patients who have undergone cardiacoperations. The aim of our study was to determine the

independent effect of limited preoperative functional

0003-4975/$36.00doi:10.1016/j.athoracsur.2012.02.071

1951Ann Thorac Surg CERVERA ET AL2012;93:1950–5 FUNCTIONAL STATUS AND CABG OUTCOMES

AD

ULT

CA

RD

IAC

status on early and late outcomes in patients who under-went CABG.

Material and Methods

This study was granted waiver of consent and wasapproved by the Institutional Review Boards at the Mi-chael E. DeBakey Veterans Affairs (VA) Medical Center(MEDVAMC) and Baylor College of Medicine, Houston,Texas.

PatientsData were obtained from the MEDVAMC ContinuousImprovement in Cardiac Surgery Program (CICSP) data-base and from a detailed retrospective review of thecomputerized patient record system. The CICSP data-base, organized by the Department of Veterans Affairs toprovide continuous assessment and improvement ofquality of care for all patients who undergo cardiacoperations in VA hospitals, contains comprehensive dataon more than 140 demographic, clinical, outcome, andresource variables collected prospectively from all car-diac surgical patients in the VA Health Care System atprespecified intervals [5].

Data in the CICSP database are collected by a researchnurse who reviews each patient’s computerized medicalrecord. The death index component of the CICSP databaseis obtained from the Beneficiary Identification RecordsLocator Subsystem (BIRLS) death file. The BIRLS is aVeterans Benefits Administration (VBA) database contain-ing records of all beneficiaries, including veterans whosesurvivors applied for death benefits. In addition to theseapplications for VA benefits, sources of data include therecords of veterans discharged from military service sinceMarch 1973, Medal of Honor recipients, and service mem-bers with accounts for VA education benefits. The BIRLSdeath file contains information on veterans known to havedied from any cause. The file can be linked to other files bythe veteran’s real or scrambled Social Security number. Aweekly match process with the Social Security Administra-tion Death Master File or a notification from a hospital,cemetery, or relative/acquaintance identifies a veteran’sdeath to be added to the file. Each January, starting in 2004,this file is refreshed with a baseline file from the VBA toensure data accuracy by removing records that may havepopulated the file inadvertently.

From the CICSP database we identified 1,503 consec-utive patients who underwent nonemergency CABG atthe MEDVAMC between October 1, 1997, and September30, 2009. We excluded patients with prior heart opera-tions and those who underwent CABG without cardio-pulmonary bypass or concomitantly with other cardiacsurgical procedures.

Data analyzed for each patient included age, sex,number of bypass grafts, cardiopulmonary bypass andaortic cross-clamp times, preoperative functional status,current tobacco smoking status, New York Heart Associ-ation (NYHA) functional class for heart failure, CanadianCardiovascular Society (CCS) angina functional class,

body mass index, preoperative albumin and creatinine

levels, prior percutaneous coronary intervention within 3days of the operation, prior myocardial infarction, andhistory of chronic obstructive pulmonary disease(COPD), peripheral vascular disease, cerebral vasculardisease, hypertension, and diabetes (as defined by theCICSP database) [5].

Our study defined patients with limited functionalstatus as those who required the use of equipment orassistance from another person for any ADL, patientsfrom nursing homes, and patients receiving long-termdialysis or oxygen therapy. The assessment of suchfunctional status impairment was based on the patient’sstatus before the index hospitalization. Specifically, pa-tients who were admitted to the intensive care unit, withor without intraaortic balloon pump support, and whowere otherwise functionally independent before hospi-talization were considered to be without any functionalimpairment. In the final analysis, we divided the cohortinto two groups: 318 patients with limited functionalstatus, as previously defined, and 1,185 patients withoutany functional impairment.

Study End PointsAll study end points were prespecified. The primary endpoints were all-cause 30-day and late mortality. The sec-ondary end points were the incidences of postoperativestroke, renal failure necessitating dialysis, mediastinitis,and reexploration for bleeding; the duration of postopera-tive ventilator support; and the 30-day perioperative rate ofmajor adverse cardiac events (MACE), which includedperioperative myocardial infarction, cardiac arrest necessi-tating cardiopulmonary resuscitation, and the need for newmechanical circulatory support. Perioperative myocardialinfarction was considered to have occurred if any of thefollowing diagnostic criteria were met: evolutionary ST-segment elevations, new Q-waves in two or more contigu-ous electrocardiographic leads, or a new left bundle branchblock pattern on the electrocardiogram. New mechanicalcirculatory support was defined as the postoperative initi-ation of support with an intraaortic balloon counterpulsa-tion pump, an extracorporeal membrane oxygenator, aventricular assist device, or any combination of these de-vices. Postoperative stroke was considered to have occurredif any new objective neurologic deficit lasted more than 72hours and appeared in the immediate postoperative periodor within 30 days after the operation.

Statistical AnalysisData from categoric variables are summarized as fre-quencies (percentages) and were compared betweengroups by using the �2 test or the Fisher exact test. Datafrom continuous variables are summarized as mean �standard deviation and were compared between groupsby using the Student t test after the data were confirmedas being normally distributed. Kaplan-Meier survivalcurves were generated, and a log-rank test was per-formed to find statistical differences.

Cox proportional hazards regression analysis was usedto examine the independent effects of functional impair-

ment as a predictor of early outcomes and late survival by

ive pu

1952 CERVERA ET AL Ann Thorac SurgFUNCTIONAL STATUS AND CABG OUTCOMES 2012;93:1950–5

AD

ULT

CA

RD

IAC

controlling for confounding covariates in the forwardstepwise regression model. Potential confounding covari-ates included in the model were age, sex, cardiopulmonarybypass and aortic cross-clamp times, number of bypassgrafts, current tobacco smoking status, NYHA functionalclass for heart failure, CCS angina functional class, bodymass index, preoperative albumin and creatinine levels,prior percutaneous coronary intervention within 3 days ofthe operation, prior myocardial infarction, and history ofcerebral vascular disease, hypertension, diabetes, periph-eral vascular disease, and COPD. All statistical analyseswere performed with SPSS 15.0 software (SPSS Inc, Chi-cago, IL).

Results

Patients with limited functional status were generallysicker (ie, had more comorbid conditions) and slightlyolder than patients who had no functional impairment byour definition (Table 1). Intraoperative characteristics(Table 2) were similar between the two groups. The onlystatistically significant difference was in the number ofbypass grafts, and this difference was not clinically sig-nificant. The unadjusted outcome measures were alsosimilar between the two groups.

After adjustment for potential confounding variablesby multivariate logistic regression analysis, preoperativefunctional status impairment itself was not an indepen-dent predictor of 30-day mortality (odds ratio [OR], 1.4;95% confidence interval [CI], 0.3 to 5.8; p � 0.67) or MACE(OR, 1.3; 95% CI, 0.5 to 3.3, p � 0.71).

Kaplan-Meier survival curves for the two groups weregenerated from all-cause mortality and censored data.Cox proportional hazards regression analysis was used to

Table 1. Preoperative Patient Characteristics

Variablea

Functional Impairm(n � 318)

Age, years 62.5 � 8.5 (45–83Male sex 316 (99.4)Body mass index, kg/m2 29.1 � 5.4Albumin, g/dL 3.5 � 0.4Creatinine, mg/dL 1.3 � 0.6Current smoker 102 (32.1)Peripheral vascular disease 126 (39.6)Cerebrovascular disease 93 (29.2)Diabetes 149 (46.9)Hypertension 300 (94.3)COPD 121 (38.1)CCS angina class III-IV 262 (82.4)NYHA functional class III-IV 184 (57.9)Prior myocardial infarction 252 (79.2)Prior PCI (� 3 days) 3 (0.9)

a Continuous data are presented as mean � standard deviation (range),

CCS � Canadian Cardiovascular Society; COPD � chronic obstructpercutaneous coronary intervention.

adjust for potential preoperative and intraoperative con-

founding factors (Tables 1 and 2). The follow-up periodfor the cohort was a mean of 65 months (range, 1 to 157months). The Cox regression-adjusted survival curves(Fig 1) showed that, independent of other predictors,patients who were deemed functionally limited preoper-atively had similar long-term survival to that of patientswithout any functional impairment (10-year hazard ratio,1.0; 95% CI, 0.7 to 1.4; p � 0.85).

No Functional Impairmentp Value(n � 1,185)

61.5 � 7.8 (31–84) 0.051179 (99.5) 0.7929.5 � 5.3 0.193.7 � 0.4 �0.00011.2 � 0.6 0.01427 (36.0) 0.21283 (23.9) �0.0001265 (22.4) 0.01483 (40.8) 0.06

1095 (92.4) 0.27386 (32.6) 0.07649 (54.8) �0.0001360 (30.4) �0.0001618 (52.2) �0.0001

4 (0.3) 0.17

number (percentage).

lmonary disease; NYHA � New York Heart Association; PCI �

Table 2. Intraoperative and Postoperative Characteristics

Variable a

FunctionalImpairment

NoFunctional

Impairment pValue(n � 318) (n � 1,185)

CPB time, min 108.3 � 35.6 108.9 � 29.9 0.78Aortic cross-clamp time,

min61.4 � 28.3 63.2 � 19.8 0.30

Vein grafts, No. 2.15 � 0.75 2.05 � 0.79 0.044IMA grafts, No. 0.96 � 0.21 0.93 � 0.32 0.022Renal failure, dialysis 7 (2.2) 7 (0.6) 0.02Mediastinitis 4 (1.3) 14 (1.2) 1.00Reexploration for bleeding 1 (0.3) 13 (1.1) 0.32Stroke 6 (1.9) 15 (1.3) 0.42On ventilator � 48 hours 29 (9.1) 72 (6.1) 0.06MACE 8 (2.5) 20 (1.7) 0.3530-day mortality 3 (0.9) 13 (1.1) 1.00

a Data are presented as mean � standard deviation or as number(percentage).

ent

)

or as

CPB � cardiopulmonary bypass; IMA � internal mammary artery;MACE � major adverse cardiac events.

1953Ann Thorac Surg CERVERA ET AL2012;93:1950–5 FUNCTIONAL STATUS AND CABG OUTCOMES

AD

ULT

CA

RD

IAC

Comment

Although functional status has been associated with theconcept of frailty, functional impairment is not synony-mous with frailty [19]. Rather, impairment of ADL is oneof the most common symptoms of frailty [20]. As ourpatient population ages, frailty seems to be emerging asa potential risk factor for adverse outcomes after surgicalprocedures [17]. Despite countless published articles onthis subject, no gold standard method of measuringfrailty exists [20]. For this reason, our study did not focuson frailty but rather on patient preoperative functionalstatus as a potential risk factor for early and late deathafter CABG procedures.

Several well-known risk factors, such as age, bodymass index, and peripheral vascular disease, have beenshown to adversely affect patients who have undergonecardiac operations [4, 21], but preoperative functionalstatus itself has not been well studied in this populationof patients. Despite anatomic and medical operability,surgeons occasionally turn down patients because oftheir poor “physiologic” status or limited functional sta-tus. Impairment in ADL has been shown to be an adverseoutcome of frailty [16] and to independently affect theoutcomes of hospitalized patients [17]. Furthermore,functional impairment adversely affects survival in can-cer patients independent of other factors [18]. As a result,we hypothesized that limited preoperative functionalstatus would also adversely affect outcomes after CABGprocedures.

Our study defined functional impairment as partial orcomplete dependence on the use of equipment or assis-tance from another person for any ADL. Patients classi-

fied as functionally impaired included patients from

nursing homes and patients receiving long-term dialysisor oxygen therapy. Contrary to the CICSP operationaldefinition of functional status [5], the assessment offunctional impairment in our study was based on thepatient’s functional status before the index hospitaliza-tion. Specifically, patients who were admitted to theintensive care unit, with or without an intraaortic balloonpump, and who were otherwise functionally indepen-dent before hospitalization were classified as not func-tionally impaired. Contrary to our hypothesis, we did notfind that impairment of preoperative functional statuswas an independent risk factor for early postoperativecomplication or death. Moreover, functionally impairedpatients who underwent CABG had similar long-termsurvival to that of patients who were otherwise function-ally independent.

There are at least two possible explanations for ourfindings: First, patient functional impairment may besecondary to the severity of their angina or heart failure.However, in our statistical analysis, we included numer-ous potential confounding variables (as described inMaterials and Methods), such as angina class and heartfailure class, as covariates in our multivariable logisticregression and Cox proportional survival analyses. Thisessentially removed the effects of these potential con-founding factors and further validated the independenteffect of functional impairment on CABG outcomes.

Second, we do not have the actual number of patientswho were deemed “nonoperable” by surgeons becauseof their severely limited functional status. Therefore, it ispossible that our findings may simply reflect careful

Fig 1. Cox regression-adjusted survivalcurves after coronary artery bypass graftingin patients with normal preoperative func-tional status (dark line) vs patients withlimited preoperative functional status (grayline).

selection among patients with limited functional status.

1954 CERVERA ET AL Ann Thorac SurgFUNCTIONAL STATUS AND CABG OUTCOMES 2012;93:1950–5

AD

ULT

CA

RD

IAC

Our study is subject to the limitations inherent in a retro-spective review. Because our patient population was limited toveterans, nearly all of our patients were men. As a conse-quence, we cannot generalize our results to women. Further-more, even though our study did not show a long-termsurvival difference between the two groups, we may be com-mitting a type II statistical error. With a power of 0.8 and � �0.05, our study of 1,503 patients was powered to detect along-term survival difference of 8% or more. Thus, a survivaldifference of less than 8% could have gone undetected in ourcohort; more patients, a longer follow-up period, or both,would have been needed to detect such an effect. Neverthe-less, the results of our current study can serve as hypothesis-generating information for future prospective studies to defin-itively answer the question of whether preoperative functionalstatus is an independent risk factor for poor long-termsurvival.

The overarching goal of our research group is toimprove outcomes in patients who undergo CABG. Thefindings of our current study represent pilot data forfuture prospective studies that will use a more compre-hensive frailty index [14] to ascertain the true indepen-dent effect of preoperative functional status on cardiacsurgical outcomes.

In summary, our study showed that preoperative func-tional impairment itself is not an independent predictorof adverse early outcomes after CABG. Furthermore,long-term survival in patients who met our definition offunctional impairment was similar to that of patients whowere functionally independent. Our results support thenotion that excellent early and late CABG outcomes maybe achieved in carefully selected patients with limitedfunctional status.

We thank Stephen N. Palmer, PhD, ELS, for his editorialassistance in the preparation of this manuscript.

References

1. United States Bureau of the Census. Statistical abstract ofthe United States, 1994: The national data book. 114th ed.Washington, D.C.: U.S. Dept. of Commerce, Economics andStatistics Administration; 1994:84.

2. Bakaeen FG, Chu D, Huh J, Carabello BA. Is an age of 80years or greater an important predictor of short-term out-comes of isolated aortic valve replacement in veterans? AnnThorac Surg 2010;90:769–74.

3. Alexander KP, Anstrom KJ, Muhlbaier LH, et al. Outcomesof cardiac surgery in patients �80 years: results from theNational Cardiovascular Network. J Am Coll Cardiol 2000;35:731–8.

4. Chu D, Bakaeen FG, Wang XL, et al. The impact of

peripheral vascular disease on long-term survival after

common reasons that patients are actually turned down for

coronary artery bypass graft surgery. Ann Thorac Surg2008;86:1175– 80.

5. Hammermeister KE, Johnson R, Marshall G, Grover FL.Continuous assessment and improvement in quality of care.A model from the Department of Veterans Affairs CardiacSurgery. Ann Surg 1994;219:281–90.

6. Shahian DM, O’Brien SM, Filardo G, et al. The Society ofThoracic Surgeons 2008 cardiac surgery risk models: part1—coronary artery bypass grafting surgery. Ann ThoracSurg 2009;88:S2–22.

7. Thourani VH, Ailawadi G, Szeto WY, et al. Outcomes ofsurgical aortic valve replacement in high-risk patients: amultiinstitutional study. Ann Thorac Surg 2011;91:49–55;discussion 56.

8. Gopaldas RR, Chu D, Dao TK, et al. Predictors of surgicalmortality and discharge status after coronary artery bypassgrafting in patients 80 years and older. Am J Surg 2009;198:633–8.

9. Wilson JF. Frailty—and its dangerous effects—might bepreventable. Ann Intern Med 2004;141:489–92.

10. Mitnitski AB, Graham JE, Mogilner AJ, Rockwood K. Frailty,fitness and late-life mortality in relation to chronological andbiological age. BMC Geriatr 2002;2:1.

11. Rockwood K, Stadnyk K, MacKnight C, McDowell I, HebertR, Hogan DB. A brief clinical instrument to classify frailty inelderly people. Lancet 1999;353:205–6.

12. Boyd CM, Xue QL, Simpson CF, Guralnik JM, Fried LP.Frailty, hospitalization, and progression of disability in acohort of disabled older women. Am J Med 2005;118:1225–31.

13. Lee DH, Buth KJ, Martin BJ, Yip AM, Hirsch GM. Frailpatients are at increased risk for mortality and prolongedinstitutional care after cardiac surgery. Circulation 2010;121:973–8.

14. Sündermann S, Dademasch A, Praetorius J, et al. Compre-hensive assessment of frailty for elderly high-risk patientsundergoing cardiac surgery. Eur J Cardiothorac Surg 2011;39:33–7.

15. Freiheit EA, Hogan DB, Eliasziw M, et al. Development of afrailty index for patients with coronary artery disease. J AmGeriatr Soc 2010;58:1526–31.

16. Vermeulen J, Neyens JC, van Rossum E, SpreeuwenbergMD, de Witte LP. Predicting ADL disability in community-dwelling elderly people using physical frailty indicators: asystematic review. BMC Geriatr 2011;11:33.

17. Ponzetto M, Maero B, Maina P, et al. Risk factors for earlyand late mortality in hospitalized older patients: the continu-ing importance of functional status. J Gerontol A Biol SciMed Sci 2003;58:1049–54.

18. Wedding U, Röhrig B, Klippstein A, Pientka L, Höffken K.Age, severe comorbidity and functional impairment inde-pendently contribute to poor survival in cancer patients. JCancer Res Clin Oncol 2007;133:945–50.

19. Fried LP, Tangen CM, Walston J, et al. Frailty in older adults:evidence for a phenotype. J Gerontol A Biol Sci Med Sci2001;56:M146–56.

20. Pel-Littel RE, Schuurmans MJ, Emmelot-Vonk MH, VerhaarHJ. Frailty: defining and measuring of a concept. J NutrHealth Aging 2009;13:390–4.

21. van Straten AH, Bramer S, Soliman Hamad MA, et al. Effectof body mass index on early and late mortality after coronary

artery bypass grafting. Ann Thorac Surg 2010;89:30–7.

DISCUSSION

DR TODD M. DEWEY (Dallas, TX): Roberto, I would like tocongratulate you and your coauthors on a timely and excellentstudy focusing on the important topic of frailty in outcomes incardiac surgery patients. Frailty, as you know, is one of the most

cardiac surgery despite several studies showing good benefit foralleviation of symptoms and long-term survival in high-riskpatient groups that can be considered frail. It is difficult, how-ever, to objectify the diagnosis of frailty, and oftentimes, it is in

the eye of the beholder. There is a somewhat consistent defini-

1955Ann Thorac Surg CERVERA ET AL2012;93:1950–5 FUNCTIONAL STATUS AND CABG OUTCOMES

AD

ULT

CA

RD

IAC

tion of frailty that has been out there, which has been defined asa syndrome of reduced reserve and resistance to stressors,resulting in declines in multiple physiologic symptoms leadingto vulnerability to adverse outcomes. However, this is generallya function of two things, chronic medical illness and age.

In your study, you and your coauthors looked at the influenceof frailty on the outcomes of over 1,500 Veterans Administration(VA) patients having coronary artery bypass grafting, and, incontradistinction to a number of other reports, found that frailtywas not a risk factor for postoperative mortality or morbidity. SoI have two questions:

Number 1, in your study you defined frailty as those patientsthat required the use of equipment or assistance from anotherperson for any activities of daily living. In your frailty group,however, the average age was only 62-1/2 years, which mostwould consider a very young population of patients havingsurgery, 99% of them were men, and they were all in the VAmedical system, which potentially means that they could haveinjuries that could affect their activities of daily living from theirservice. How can you and your coauthors be sure that you arenot actually measuring the effect of disability on outcomes asopposed to frailty?

My second question relates to the use of gait speed and otherprovocative measures as a marker of frailty in patients under-going cardiac surgery, especially since this is now a measuredvariable in the new The Society of Thoracic Surgeons (STS) datatool, which started in July of this year. Given your experiencewith this study, how should surgeons incorporate provocativetesting of patients using gait speed, grip strength, and othermeasures into their decision to offer patients cardiovascularsurgery? Thank you.

DR CERVERA: Thank you, Dr Dewey. Those are very validpoints. In reference to the first question, in a retrospective studylike this with the database we have, it is actually very difficult totease out these particular patients, and it kind of alludes to thefact that we should work hard like you folks have up in Dallas tohave a more comprehensive assessment of frailty index.

In reference to your second question, it goes back to basicallythe same concept in answering the first question. Gait speed isjust one marker of frailty based on the performance of thepatient, and it is not a comprehensive assessment of frailty. So Ithink when we approach these patients, we essentially have to

have more of a comprehensive approach to them.

DR J. W. RANDOLPH BOLTON (Fresno, CA): I am curious as towhy you excluded the off-pump patients.

DR CERVERA: Well, essentially, it wasn’t our objective of thestudy to look at the off-pump patients.

DR CHU: Perhaps I can answer it better. I am the senior authoron the paper. To answer the question about why we excludedoff-pump patients, it is because off-pump may itself have someeffect on outcome, which has been shown in numerous studies.So I wanted to be able to identify the independent factor offrailty on outcome. That is one reason.

And to answer Dr Dewey’s questions, although frailty is anemerging concept, there is really no consensus on how to defineit. And although we define it as most published literature does,such as any impairment of activities of daily living, it is accept-able but not an ideal definition, and as Dr Cerfolio pointed out,the results only are as good as your method is.

So what this paper actually shows is that the surgeon’s gutfeeling is immeasurable. We don’t have the bottom line of howmany patients were turned down because they were consideredfrail or functionally limited. So without that denominator, thispaper shows that carefully selected patients who are by ourdefinition frail have similar outcomes and good long-term sur-vival as others. So it says that we are picking patients right eventhough they are considered frail.

And that points to the fact that we need a more compre-hensive test such as what Dr Dewey and the folks at DallasCity have pioneered, the comprehensive frailty index assess-ment score, to give us a better idea of how to objectivelyevaluate these patients. But again, even with the STS riskcalculation, even if we have a comprehensive frailty assess-ment score, I don’t think anything can measure a surgeon’sexperience and gut feeling.

DR NIRMAL VEERAMACHANENI (Chapel Hill, NC): In termsof your outcome measures in the elderly population, I wouldsuggest one other measure—how many of the patients areactually able to leave the hospital and go home. Do you havedata on how many ended up in a nursing home or how manyended up being able to go back to their original home situations?

DR CHU: That is a great question. We do have the data on that.We haven’t looked at that, but that is certainly something that

we could look at for our next project.