* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Outcome of Patients With Low Ejection Fraction
Survey
Document related concepts
Cardiac contractility modulation wikipedia , lookup
Remote ischemic conditioning wikipedia , lookup
History of invasive and interventional cardiology wikipedia , lookup
Myocardial infarction wikipedia , lookup
Drug-eluting stent wikipedia , lookup
Coronary artery disease wikipedia , lookup
Transcript
Outcome of Patients With Low Ejection Fraction Undergoing Coronary Artery Bypass Grafting Renal Function and Mortality After 3.8 Years Graham S. Hillis, MBChB, PhD; Kenton J. Zehr, MD; Amy W. Williams, MD; Hartzell V. Schaff, MD; Thomas A. Orzulak, MD; Richard C. Daly, MD; Charles J. Mullany, MD; Richard J. Rodeheffer, MD; Jae K. Oh, MD Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 Background—There are few data regarding medium-term outcome of coronary artery bypass grafting (CABG) in patients with severe left ventricular (LV) systolic dysfunction, particularly in the modern era, and even less assessing preoperative factors that might identify patients at highest risk. Methods and Results—Three hundred seventy-nine consecutive patients with LV ejection fraction ⱕ35%, who underwent isolated first CABG between 1995 and 1999 were studied. Potential preoperative and perioperative predictors of outcome were recorded and patients followed-up for a median of 3.8 years. The primary study end-point was all-cause mortality. The 30-day, 1-year, and 3-year survival rates were 94.5%, 88%, and 81%, respectively. The independent predictors of mortality were preoperative estimated glomerular filtration rate (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.97 to 0.99 per mL/min/1.73m2; P⬍0.001) and age (HR, 1.03; 95% CI, 1.01 to 1.06 per year; P⫽0.005). Conclusions—Patients with significant LV systolic dysfunction undergoing isolated CABG using contemporary techniques have a good medium-term survival. Renal dysfunction is the strongest independent predictor of mortality. (Circulation. 2006;114[suppl I]:I-414–I-419.) Key Words: coronary disease 䡲 kidney 䡲 surgery 䡲 survival M ajor randomized control studies comparing medical therapy with coronary artery bypass grafting (CABG) did not recruit patients with a left ventricular (LV) ejection fraction ⬍35%. They did, however, demonstrate improved survival in surgically treated patients with milder degrees of LV systolic dysfunction.1,2 Likewise, cohort studies and data on nonrandomized patients from the Coronary Artery Surgery Study registry have also favored surgical revascularization over medical therapy.3,4 These data suggest that CABG may improve prognosis in selected patients with coronary heart disease and severely impaired systolic function, and it is frequently performed on this patient population.5 It is, however, associated with a modest increase in risk compared with patients with normal LV function,5–7 with some older publications reporting extreme variations in outcome. Nevertheless, previous studies have primarily addressed early (inhospital and/or 30-day) outcome, with limited contemporary data regarding longer-term mortality and morbidity. Likewise, there are few data assessing the preoperative factors that might identify patients who are at highest risk. To address these issues, the current study reports the medium-term outcome of a large cohort of consecutive patients with LV ejection fraction ⱕ35%, who underwent isolated first CABG surgery between 1995 and 1999, and the factors influencing this. Methods Patients The study was approved by the Mayo Foundation Institutional Review Board. All patients who underwent isolated first CABG at the Mayo Clinic, Rochester, Minnesota between January 1, 1995 and December 31, 1999, and whose preoperative LV ejection fraction was ⱕ35%, were identified (n⫽379). In 195 patients (51%) this was determined by echocardiography, in 169 (45%) left ventriculography and in 15 (4%) by radionuclide scanning. Patients undergoing re-do CABG, concomitant valvular surgery, cardioverter-defibrillator implantation, aneurysmectomy, or ventricular septal defect repair were excluded. Measures Demographic and clinical data were recorded, including the preoperative Canadian Cardiovascular Society (CCS) angina class and the New York Heart Association (NYHA) functional class. Preoperative hemoglobin and creatinine and levels were documented (using the sample taken immediately before surgery) and the glomerular filtration rate estimated (eGFR) using the Modification of Diet in Renal Disease equation.8 Using this equation the eGFR (mL/min/ 1.73m2) ⫽ 186 ⫻ (serum creatinine level [mg per deciliter])⫺1.154⫻ (age [years])⫺0.203. The product of this equation was multiplied by a correction factor of 0.742 for women and 1.212 for blacks.8 Patients were categorized into 4 groups dependent on their eGFR (ⱖ75 mL/min/1.73m2, 60 to 74 mL/min/1.73m2, 45 to 59 mL/min/1.73m2, ⬍45 mL/min/1.73m2), as described by the US National Kidney From the Divisions of Cardiovascular Disease (G.S.H., R.J.R, J.K.O.), Nephrology (A.W.W) and Cardiovascular Surgery (K.J.Z., H.V.S., T.A.O., R.C.D., C.J.M.), Mayo Clinic, Rochester, Minn. Presented at the American Heart Association Scientific Sessions, Dallas, Tex, November 13–16, 2005. Correspondence to Jae Oh, Division of Cardiovascular Diseases, Mayo Clinic, 200 First Street SW, Rochester, MN 55905. E-mail [email protected] © 2006 American Heart Association, Inc. Circulation is available at http://www.circulationaha.org DOI: 10.1161/CIRCULATIONAHA.105.000661 I-414 Hillis et al TABLE 1. CABG and Low Ejection Fraction I-415 Clinical Characteristics Characteristic All Patients (n⫽379) Alive (n⫽272) Died (n⫽107) Hazard Ratio (95% CI) P Age, years 69 (61–76) 68 (61–75) 73 (66–77) 1.05 (1.02–1.07) ⬍0.001 Risk factors and medical history Male 286 (76%) 202 (74%) 84 (79%) 1.16 (0.73–1.84) 0.53 79 (21%) 61 (22%) 18 (17%) 0.76 (0.46–1.27) 0.30 Diabetes 150 (40%) 113 (42%) 37 (35%) 0.75 (0.50–1.12) 0.16 Hypertension 246 (65%) 174 (64%) 72 (67%) 1.06 (0.71–1.59) 0.78 Previous PCI 59 (16%) 41 (15%) 18 (17%) 1.15 (0.69–1.91) 0.60 Previous myocardial infarction 263 (69%) 191 (70%) 76 (71%) 1.06 (0.70–1.61) 0.78 Myocardial infarction in prior month Current smoker 145 (38%) 104 (38%) 41 (38%) 1.00 (0.68–1.48) 1.00 Normal ECG 33 (9%) 25 (9%) 8 (7%) 0.75 (0.37–1.55) 0.44 Echocardiographic LVEF 28 (23–33) 28 (23–33) 28 (24–33) 1.01 (0.97–1.05) 0.68 Creatinine (mg/dL) 1.2 (1.0–1.4) 1.2 (1.0–1.4) 1.3 (1.1–1.8) 1.57 (1.29–1.92) ⬍0.001 Creatinine ⱖ1.5 mg/dL 93 (25%) 55 (20%) 38 (36%) 1.86 (1.25–2.76) 0.002 eGFR (mL/min/1.73m2) 59 (47–72) 63 (51–75) 53 (38–64) 0.97 (0.96–0.98) ⬍0.001 72 (67%) 2.01 (1.34–3.01) 0.001 0.90 (0.81–1.01) 0.07 Blood results Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 eGFR ⬍60 mL/min/1.73m2 197 (52%) 125 (46%) Hemoglobin (g/dL) 13.1 (12.1–14.2) 13.3 (12.2–14.3) 12.9 (11.9–14.0) Therapy before CABG ACE inhibitor/ARB 211 (56%) 158 (58%) 53 (50%) 0.82 (0.56–1.19) 0.29  -blocker 156 (41%) 117 (43%) 39 (36%) 0.97 (0.65–1.44) 0.88 Statin 106 (28%) 86 (32%) 20 (19%) 0.66 (0.41–1.08) 0.10 Loop diuretic 145 (38%) 98 (36%) 47 (44%) 1.36 (0.92–1.98) 0.12 I or II 193 (51%) 146 (54%) 47 (44%) III or IV 186 (49%) 126 (46%) 60 (56%) 1.37 (0.94–2.01) 0.10 I or II 176 (46%) 130 (48%) 46 (43%) III or IV 201 (53%) 141 (52%) 60 (57%) 1.28 (0.87–1.88) 0.20 CCS angina status NYHA functional class ACE indicates angiotensin-converting enzyme; ARB, angiotensin II receptor blocker; CABG, coronary artery bypass grafting; CCS, Canadian Cardiovascular Society; CI, confidence interval; ECG, electrocardiogram; eGFR, estimated glomerular filtration rate; LVEF, left ventricular ejection fraction; NYHA, New York Heart Association; PCI, percutaneous coronary intervention. NYHA functional class could not be determined in 2 cases. Foundation.8 Angiographic data and operative details were recorded, with an angiographic stenosis of ⱖ50% considered significant. Follow-Up Patients were followed-up between January and June 2002. Initially, a review of Mayo Clinic records was performed. Patients were then contacted by telephone to confirm the recorded data and ensure that events treated at other institutions were documented. A scripted telephone interview was used to determine symptom status (CCS angina score and NYHA class). When telephone contact could not be established, a mailed questionnaire was used. If necessary the patient’s cardiologist or primary physician was contacted to acquire missing information, confirm the data, and/or obtain updated contact details. If the patient could not be contacted, vital status was established using the Social Security Index. The primary study end-point was all-cause mortality. In addition, data were collected regarding nonfatal myocardial infarction (defined using standard criteria pertaining at the time it occurred9,10), further myocardial revascularization, cardiac transplantation, and symptom status at follow-up. Statistical Analyses Continuous data are expressed as median (interquartile range) and categorical data as absolute values (percentage). Survival was plotted using the Kaplan-Meier method and compared using the log-rank statistic. Estimations of risk were performed using the Cox proportional hazard method. Potential independent predictors of outcome were identified by univariable analyses. Univariable predictors were entered in a stepwise manner into a multivariable model of survival, with entry and retention set at a significance level of ⬍0.05. SPSS version 9.0 (SPSS Inc, Chicago, Ill) was used for all analyses. Results Patient Population The clinical characteristics of the study cohort are shown in Table 1. At the time of surgery, 150 patients (40%) had CCS class I angina, 43 (11%) class II, and 186 (49%) CCS class III or IV. Sixty-eight of the 201 (34%) patients with NYHA functional class III or IV symptoms had little or no angina (CCS class I) at the time of surgery. Fifty-nine patients had undergone 75 previous percutaneous coronary interventions. One patient was receiving renal replacement therapy before surgery and 1 patient had a pre-existing implantable cardioverter-defibrillator. I-416 Circulation July 4, 2006 TABLE 2. Angiographic and Operative Characteristics Characteristic All Patients (n⫽379) Alive (n⫽272) Died (n⫽107) Hazard Ratio (95% CI) P Angiographic findings Left main stem stenosis 121 84 (31%) 37 (35%) 1.17 (0.79–1.74) 0.44 Three vessel coronary artery disease 307 222 (82%) 85 (79%) 0.88 (0.55–1.40) 0.59 LV ejection fraction (%) 31 (25–33) 31 (25–33) 30 (25–33) 1.00 (0.95–1.05) 0.89 End diastolic pressure (mm Hg) 26 (19–32) 27 (20–33) 25 (17–28) 0.97 (0.94–1.00) 0.05 Operative details IABP preoperatively 54 36 (13%) 18 (17%) 1.34 (0.81–2.23) 0.26 Three or more grafts 315 230 (85%) 85 (79%) 0.63 (0.39–1.00) 0.05 352 260 (96%) Internal mammary graft used 92 (86%) 0.41 (0.23–0.70) 0.001 Bypass time (minutes)* 88 (66–114) 87 (65–112) 93 (69–118) 1.00 (1.00–1.01) 0.35 Cross-clamp time (minutes) * 50 (34–61) 50 (36–61) 49 (33–62) 1.00 (0.99–1.01) 0.76 0.75 (0.27–2.04) 0.57 ⬘Off-pump⬘ CABG 16 12 (4%) 4 (4%) Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 *Excludes surgery performed “off-pump” (n⫽16). IABP indicates intra-aortic balloon pump. Preoperative Investigations and Operative Details Results of preoperative investigations are shown in Tables 1 and 2. Of the total cohort, 337 patients (89%) had either significant (ⱖ50%) left main stem stenosis or 3-vessel coronary artery disease or both (Table 2). Sixteen patients (4%) underwent surgery without the use of cardiopulmonary bypass (“off pump”). Total bypass and aortic cross-clamp times for the remaining patients are shown in Table 2. Follow-Up Vital status data were obtained on all patients a median of 3.8 (2.5 to 5.3) years after surgery. The 30-day mortality rate was 5.5% (21/379). Four of these deaths occurred within 1-day of surgery. There were 86 late (after 30-days) deaths. The 1- and 3-year survival rates were 88% and 81%, respectively. Among the 272 survivors, 21 patients sustained a total of 22 nonfatal acute myocardial infarctions and 16 patients underwent further myocardial revascularization (15 percutaneous coronary interventions and 1 re-do CABG). No patients underwent cardiac transplantation during follow-up. Two patients required renal replacement therapy within 7 days of surgery. At follow-up, the CCS angina class was available in 235 patients (86% of survivors) and NYHA functional class in 236 patients (87%). Only 12 surviving patients had a CCS angina class ⬎II, in comparison to 105 of the same patients at baseline. Thirty-nine survivors were in NHYA class III or IV, compared with 122 of the same patients at baseline. Univariable Predictors of Mortality The most powerful predictors of mortality during long-term follow-up were renal function and age (Table 1 and Figures 1 Figure 1. The effect of age on survival after coronary artery bypass grafting. Hillis et al CABG and Low Ejection Fraction I-417 Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 Figure 2. The effect of creatinine on survival after coronary artery bypass grafting. to 3). Receipt of an internal mammary artery graft was also associated with improved survival. When patients who had sustained an acute myocardial infarction in the month before their index CABG (n⫽145, 38%) were excluded, the univariable predictors of mortality were age (hazard ratio [HR], 1.05 per year; 95% confidence interval [CI], 1.02 to 1.08; P⫽0.001), creatinine (HR, 1.56 per mg/dL; 95% CI, 1.20 to 2.04; P⫽0.001), eGFR (HR, 0.97 per mL/min/1.73m2; 95% CI, 0.96 to 0.99; P⬍0.001), eGFR ⬍60 mL/min/1.73m2 (HR, 1.76; 95% CI, 1.06 to 2.90; P⫽0.03), CCS class 3 or 4 angina (HR, 1.65; 95% CI, 1.02 to 2.68; P⫽0.04), and receipt of an internal mammary artery graft (HR, 0.32; 95% CI, 0.14 to 0.75; P⫽0.008). Multivariable Predictors of Mortality Serum creatinine and eGFR are mathematically related. In this cohort, however, eGFR was a stronger univariable predictor of mortality (2 25.9 versus 20.6; P⫽0.02), and Figure 3. The effect of estimated glomerular filtration rate on survival after coronary artery bypass grafting. I-418 Circulation TABLE 3. Multivariable Predictors of Mortality Characteristic July 4, 2006 Wald 2 Hazard ratio 95% CI eGFR 0.98* 0.97–0.99 17.57 ⬍0.001 Age 1.03† 1.01–1.06 8.01 0.005 1.82 0.18 IMA graft P 2 *Hazard ratio per mL/min/1.73m . †Hazard ratio per year. IMA indicates internal mammary artery. Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 when this was used creatinine provided no additional prognostic information. Estimated GFR was, therefore, used in a stepwise multivariable model that included other univariable predictors of outcome (P⬍0.05: age and receipt of an internal mammary artery graft). The independent predictors of mortality were eGFR and age (Table 3 and Figures 1 and 3). Patients with an eGFR of ⬍45 mL/min/1.73m2 were at particularly high risk (Table 4 and Figure 3). When the 145 patients who had sustained an acute myocardial infarction in the month before their index CABG were excluded, the independent predictors of mortality were eGFR (HR, 0.98 per mL/min/1.73m2; 95% CI, 0.96 to 0.99; 2 9.2; P⫽0.002), age (HR, 1.04 per year; 95% CI, 1.01 to 1.07; 2 6.0; P⫽0.01), and receipt of an internal mammary artery graft (HR, 0.41; 95% CI, 0.17 to 0.97; 2 4.2; P⫽0.04). Discussion Although patients with advanced LV systolic dysfunction frequently undergo CABG there are few contemporary data assessing the outcome of such individuals beyond the early postoperative period. Likewise, the predictors of mediumterm outcome are poorly documented, as are the symptomatic benefits of such therapy. The main findings of the current study were that during a median of 3.8 years of follow-up 28% of patients had died, with a 30-day mortality rate of 5.5%. The independent predictors of mortality were increasing age and impaired renal function. The most powerful predictor was the preoperative eGFR. Patient Characteristics, Preoperative Therapy, and Investigation The cohort were elderly, with a high prevalence of cardiovascular risk factors. The majority of patients had significant limiting angina and/or a pattern of coronary artery disease, whereby CABG would be recommended in current guidelines.11 Likewise, the majority of patients were in NYHA functional class III or IV. Use of angiotensin-converting enzyme inhibitors and/or angiotensin II receptor blockers, -blockers, and statins was lower than optimal, but higher than reported in other comparable cohorts12 and in large contemporary North American databases.13,14 Use of all of these agents was significantly higher during the second half of the study period (data not shown). Predictors of Mortality The increasing perioperative risks associated with CABG in elderly patients have been well-documented11 and some previous data suggest that the risks are particularly high in those with reduced LV ejection fraction.5,15,16 Others, however, have failed to demonstrate an independent relationship between age and outcome in this setting.12,17–20 Our data suggest it is an important determinant, with those dying within 30 days having a median age of 76 years compared with 69 years among survivors. In this cohort, patients 75 years of age and older had a 5-year survival of ⬍30%. Higher NYHA functional class was not associated with increased mortality. This is contrast to the findings from the Coronary Artery Bypass Grafting Patch Trial database.12 However, in this study, the excess risk was observed only when comparing an absence of heart failure symptoms with any degree of limitation and the increased risk was similar regardless of the severity of heart failure, with mortality among patients with grade IV symptoms slightly lower than those in class I, II, or III. Although other groups have reported an increased perioperative mortality among patients with severe symptoms of heart failure undergoing CABG,21 there is considerable variation between centers and several studies assessing long-term outcome have failed to find any such relationship.16,18,19 Several other notable clinical factors did not influence mortality. These included patient gender, diabetes mellitus, hypertension, use of an intra-aortic balloon pump preoperatively, and recent acute myocardial infarction. The preoperative LV ejection fraction (measured either by left ventriculography or echocardiography) was also of no prognostic significance. This may reflect a declining influence on perioperative mortality22 but may also be caused by the relative homogeneity of the cohort in this respect. Certainly, LV ejection fraction is an important prognostic factor in less selected populations.11 Renal Function and Outcome Mortality rates after CABG in patients with end-stage renal disease are know to be higher.11 In addition, the importance of milder degrees of renal dysfunction is increasingly recognized.23,24 Nevertheless, the particular importance of renal impairment in the outcome of patients with depressed LV systolic function has not been well-documented. One previous study of 80 patients with a LV ejection fraction ⱕ30% followed for a mean of 15 months demon- TABLE 4. Relative Unadjusted and Adjusted Risk for Mortality Stratified by Estimated Glomerular Filtration Rate Unadjusted Hazard Ratio (95% CI) Characteristic Hazard Ratio (95% CI) Adjusted for Age and Gender Hazard Ratio (95% CI) With Mutivariable Adjustment* eGFR ⱖ75 mL/min/1.73m2 (n⫽78) 1 1 1 eGFR 60–74 mL/min/1.73m2 (n⫽104) 1.81(0.87–3.78) 1.72(0.82–3.58) 1.71(0.82–3.58) eGFR 45–59 mL/min/1.73m2 (n⫽120) 2.13(1.05–4.33) 1.90(0.92–3.89) 1.65(0.80–3.41) eGFR ⬍45 mL/min/1.73m2 (n⫽77) 4.43(2.21–8.88) 3.59(1.76–7.32) 2.66(1.14–6.20) *Adjusted for age, creatinine, and use of an internal mammary artery graft. Hillis et al strated that a creatinine of ⱖ180 mol/L (2 mg/dL) was associated with a higher cardiac mortality,17 whereas others have reported a considerable increase in risk among patients with low ejection fraction requiring dialysis before CABG.5 The importance of renal dysfunction has not, however, been replicated in all studies.16,18–20 This is surprising, particularly because impaired renal function increases cardiovascular risk and is a powerful predictor of a poor prognosis in patients with LV systolic dysfunction.25 Certainly, the current data suggest that, among patients with significant LV systolic dysfunction undergoing CABG, renal function, measured using either serum creatinine or eGFR, is the single most powerful predictor of medium-term outcome. Further work is required to assess whether measures to improve renal function and correct associated abnormalities might improve surgical prognosis in this high-risk group. 7. 8. 9. 10. 11. Strengths and Limitations of the Current Study Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 The large cohort of consecutive patients ensures that total mortality can be used as the primary end-point. In addition, symptomatic status at follow-up is available in a large number of patients. However, the lack of data regarding myocardial function after surgery is a weakness and the study has the limitations inherent in a retrospective cohort design. Finally, the study cannot address the relative benefits of medical therapy alone versus a combination of medical therapy plus surgical revascularization in patients with severe ischemic LV dysfunction. This can only be adequately evaluated in a prospective study. 12. 13. 14. Conclusions The current study demonstrates that patients with significant LV systolic dysfunction undergoing isolated first CABG using contemporary techniques have a good early and medium-term survival. In addition, the majority of survivors derive considerable symptomatic benefit. Renal dysfunction portends a very poor prognosis in this setting. Further work is required to determine strategies that can improve the outcome of these individuals at high risk. 15. 16. 17. 18. Source of Funding Dr Hillis was supported by the British Heart Foundation. Disclosures 19. None. 20. References 1. CASS principal investigators and their associates. Coronary Artery Surgery Study (CASS): a randomized trial of coronary artery bypass surgery. Survival data. Circulation. 1983;68:939 –950. 2. The Veterans Administration Coronary Artery Bypass Surgery Cooperative Study Group. Eleven year survival in the Veterans Administration randomized trial of coronary bypass surgery for stable angina. N Engl J Med. 1984;311:1333–1339. 3. Baker DW, RJ, Hodges J, Massie BM, Konstam MA, Rose EA. Management of heart failure. The role of revascularization in the treatment of patients with moderate or severe left ventricular systolic dysfunction. JAMA. 1994;272:1528 –1534. 4. Alderman EL, Fisher LD, Litwin P, Kaiser GC, Myers WO, Maynard C, Levine F, Schloss M. Results of coronary artery surgery in patients with poor left ventricular function (CASS). Circulation. 1983;68:785–795. 5. Topkara VK, Cheema FH, Kesavaramanujam S, Mercando ML, Cheema AF, Namerow PB, Argenziano M, Naka Y, Oz MC, Esrig BC. Coronary artery bypass grafting in patients with low ejection fraction. Circulation. 2005;112[suppl I]:I-344 –I-350. 6. Appoo J, Norris C, Merali S, Graham MM, Koshal A, Knudtson ML, Ghali WA. Long-term outcome of isolated coronary artery bypass surgery 21. 22. 23. 24. 25. CABG and Low Ejection Fraction I-419 in patients with severe left ventricular dysfunction. Circulation. 2004; 110(suppl II):II-13–II-17. Trachiotis GD, Weintraub WS, Johnston TS, Jones EL, Guyton RA, Craver JM. Coronary artery bypass grafting in patients with advanced left ventricular dysfunction. Ann Thorac Surg. 1998;66:1632–1639. Levey AS, Bosch JP, Lewis JB, Greene T, Rodgers N, Roth D. A more accurate method to estimate glomerular filtration rate from serum creatinine: a new prediction equation. Modification of Diet in Renal Disease Study Group. Ann Intern Med. 1999;130:461– 470. Tunstall-Pedoe H, Kuulasmaa K, Amouyel P, Arveiler D, Rajakangas AM, Pajak A. Myocardial infarction and coronary deaths in the World Health Organization MONICA Project. Circulation. 1994;89:583– 612. The Joint European Society of Cardiology/American College of Cardiology Committee. Myocardial infarction redefined - A consensus document of The Joint European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction. J Am Coll Cardiol. 2000;36:959 –969. Eagle KA, Guyton RA, Davidoff R, Ewy GA, Fonger J, Gardner TJ, Gott JP, Herrmann HC, Marlow RA, Nugent WC, O’Connor GT, Orszulak TA, Rieselbach RE, Winters WL, Yusuf S, Gibbons RJ, Alpert JS, Eagle KA, Garson A, Jr, Gregoratos G, Russell RO, Smith SC Jr. ACC/AHA Guidelines for Coronary Artery Bypass Graft Surgery: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Revise the 1991 Guidelines for Coronary Artery Bypass Graft Surgery). American College of Cardiology/American Heart Association. J Am Coll Cardiol. 1999;34:1262–1347. Argenziano M, Spotnitz HM, Whang W, Bigger JT, Parides M, Rose EA. Risk stratification for coronary artery bypass surgery in patients with left ventricular dysfunction. Analysis of the Coronary Artery Bypass Grafting Patch Trial database. Circulation. 1999;100(suppl II):II-119 –II-124. Johnson D, Jin Y, Quan H, Cujec B. Beta-blockers and angiotensinconverting enzyme inhibitors/receptor blockers prescriptions after hospital discharge for heart failure are associated with decreased mortality in Alberta, Canada. J Am Coll Cardiol. 2003;42:1438 –1445. Stafford RS, Radley DC. The underutilization of cardiac medications of proven benefit, 1990 to 2002. J Am Coll Cardiol. 2003;41:56 – 61. Ivanov J, Weisel RD, David TE, Naylor D. Fifteen-year trends in risk severity and operative mortality in elderly patients undergoing coronary artery bypass graft surgery. Circulation. 1998;97:673– 680. Mickleborough LL, Maruyama H, Takagi Y, Mohamed S, Sun Z, Ebisuzaki L. Results of revascularization in patients with severe left ventricular dysfunction. Circulation. 1995;92(suppl II):II-73–II-79. De Carlo M, Milano A, Borzoni G, Pratali S, Barzaghi C, Tartarini G, Mariani M, Bortolotti U. Predicting outcome after myocardial revascularization in patients with left ventricular dysfunction. Cardiovasc Surg. 1998;6:58–66. Bouchart F, Tabley A, Litzler PY, Haas-Hubscher C, Bessou JP, Soyer R. Myocardial revascularization in patients with severe ischemic left ventricular dysfunction. Long-term follow-up in 141 patients. Eur J Cardiothorac Surg. 2001;20:1157–1162. Milano CA, White WD, Smith LR, Jones RH, Lowe JE, Smith PK, Van Trigt, P. 3rd. Coronary artery bypass in patients with severely depressed ventricular function. Ann Thorac Surg. 1993;56:487– 493. Shah PJ, Hare DL, Raman JS, Gordon I, Chan RK, Horowitz JD, Rosalion A, Buxton BF. Survival after myocardial revascularization for ischemic cardiomyopathy: A prospective ten-year follow-up study. J Thorac Cardiovasc Surg. 2003;126:1320 –1327. Weschler AS, Junod FL. Coronary bypass grafting in patients with chronic congestive heart failure. Circulation. 1989;79(suppl I):I-92–I-96. Davierwala PM, Maganti M, Yau TM. Decreasing significance of left ventricular dysfunction and reoperative surgery in predicting coronary artery bypass grafting-associated mortality: A twelve year study. J Thorac Cardiovasc Surg. 2003;126:1335–1344. Zakeri R, Freemantle N, Barnett V, Lipkin GW, Bonser RS, Graham TR, Rooney SJ, Wilson IC, Cramb R, Keogh BE, Pagano D. Relation between mild renal dysfunction and outcomes after coronary artery bypass grafting. Circulation. 2005;112(suppl I):I-270-I-275. Hillis GS, Croal BL, Buchan KG, El-Shafei H, Gibson G, Jeffrey RR, Millar CGM, Prescott GJ, Cuthbertson BH. Renal function and outcome from coronary artery bypass grafting: impact on mortality after 2.3 year follow-up. Circulation. 2006;113:1056 –1062. Dries DL, Exner DV, Domanski MJ, Greenberg B, Stevenson LW. The prognostic implications of renal insufficiency in asymptomatic and symptomatic patients with left ventricular systolic dysfunction. J Am Coll Cardiol. 2000;35:681– 689. Outcome of Patients With Low Ejection Fraction Undergoing Coronary Artery Bypass Grafting: Renal Function and Mortality After 3.8 Years Graham S. Hillis, Kenton J. Zehr, Amy W. Williams, Hartzell V. Schaff, Thomas A. Orzulak, Richard C. Daly, Charles J. Mullany, Richard J. Rodeheffer and Jae K. Oh Downloaded from http://circ.ahajournals.org/ by guest on June 12, 2017 Circulation. 2006;114:I-414-I-419 doi: 10.1161/CIRCULATIONAHA.105.000661 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 2006 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539 The online version of this article, along with updated information and services, is located on the World Wide Web at: http://circ.ahajournals.org/content/114/1_suppl/I-414 Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Circulation is online at: http://circ.ahajournals.org//subscriptions/