A response to ‘Beta-blockers for elective surgery in elderly patients: population based, retrospective cohort study’.
EDITOR- Redelmeier and colleagues have presented important evidence on the need to consider the duration of action of beta-blockers in the peri-operative period.1 However, they have failed to recognise two important issues, which may result in the reader of their paper misinterpreting the data they present.
Firstly, when they discuss the potential cardioprotective benefits of peri-operative beta-blockade they refer specifically to acute peri-operative beta-blocker administration.2 Their study design however identifies patients who had beta-blockers administered in the year prior to surgery, assuming that these beta-blockers would be continued into the peri-operative period.1 Their paper therefore describes patients undergoing surgery on chronic (as opposed to acute) beta-blockade. This distinction is vital, as although acute peri-operative beta-blockade may provide peri-operative cardioprotection,3 there is currently no evidence of cardioprotective efficacy of chronic beta-blockade in the peri-operative period.4
This brings us to the second point. Unfortunately, there was no control group consisting of patients who were not on chronic beta-blocker therapy in the peri-operative period. The concern therefore is that although there was a significant difference in outcome between the metoprolol and atenolol patient groups, we do not know how this compares to patients who did not receive peri-operative beta-blockers. Although atenolol was shown to be safer than metoprolol,1 this does not imply that chronic atenolol therapy is cardioprotective in the peri-operative period.4
In various studies, we have been unable to show a difference in a number of postoperative cardiac outcomes between patients who were chronically beta-blocked and patients who were not. There was no difference in postoperative silent myocardial ischaemia,5,6 postoperative troponin I or T release above the upper reference limit,7 30 day mortality,8,9 and 1 year mortality,6 as shown in the Table.
Table 1. Cardiac outcomes in chronically beta-blocked patients undergoing elective surgery
First author
Study design
Number of patients
Outcome
Odds ratio(95% CI)
Sear and Giles5,6
Observational
510
Postoperative SMI
1.01 (0.60-1.69)*
Higham7
Observational
155
Postoperative troponin I or T release
3.15 (1.00-9.67)
Sear8
Case-control (1979-1992)
115 pairs
30 day mortality
2.04 (1.00-3.17)*
1.00 (0.41-2.44) †
Sear9
Case-control (1991-1998)
83 pairs
30 day mortality
1.30 (0.53-3.31)*
2.07 (0.71-6.08) ††
Giles6and unpublished data
Observational
327
1 year cardiac death or major cardiac complication
0.99 (0.47-2.04)
SMI silent myocardial ischaemia
* unadjusted
† adjusted for calcium channel blockers, history of angina and hypertension
††adjusted for congestive heart failure, left ventricular hypertrophy and nitrate therapy
We must therefore disagree with Redelmeier et al1 in that chronic beta-blockade appears to afford no protection for peri-operative cardiac events. Our observations tally with those of Lee et al10 in the patient cohort in whom they defined the risk factors in their index.
1. Redelmeier D, Scales D, Kopp A. Beta blockers for elective surgery in elderly patients: population based, retrospective cohort study. BMJ 2005;331:932.
2. Auerbach AD, Goldman L. beta-Blockers and reduction of cardiac events in noncardiac surgery: scientific review. JAMA 2002;287:1435-44.
3. Devereaux PJ, Beattie WS, Choi PT, Badner NH, Guyatt GH, Villar JC, et al. How strong is the evidence for the use of perioperative beta blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials. BMJ 2005;331:313-21.
4. Giles JW, Sear JW, Foex P. Effect of chronic beta-blockade on peri-operative outcome in patients undergoing non-cardiac surgery: an analysis of observational and case control studies. Anaesthesia 2004;59:574-83.
5. Sear JW, Foex P, Howell SJ. Effect of chronic intercurrent medication with beta-adrenoceptor blockade or calcium channel entry blockade on postoperative silent myocardial ischaemia. Br J Anaesth 2000;84:311-5.
6. Giles JW, Sear JW, Higham H, Sear YM. Chronic beta-adrenoceptor blockade does not reduce incidence of early adverse cardiac outcomes in vascular surgery patients. Br J Anaesth 2003;90:419P.
7. Higham H, Sear JW, Sear YM, Kemp M, Hooper RJ, Foex P. Peri-operative troponin I concentration as a marker of long-term postoperative adverse cardiac outcomes--a study in high-risk surgical patients. Anaesthesia 2004;59:318-23.
8. Sear JW, Howell SJ, Sear YM, Yeates D, Goldacre M, Foex P. Intercurrent drug therapy and perioperative cardiovascular mortality in elective and urgent/emergency surgical patientst. Br J Anaesth 2001;86:506-12.
9. Sear JW, Howell SJ, Sear Y, M., Yeates D, Goldacre M, Foex P. A nested case-control study of risk factors for perioperative cardiovascular death. Br J Anaesth 2001;87:669P.
10. Lee TH, Marcantonio ER, Mangione CM, Thomas EJ, Polanczyk CA, Cook EF, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999;100:1043-9.
Competing interests:
None declared
Competing interests:
No competing interests
22 November 2005
Bruce M Biccard
Clinical Research Fellow
Julian W. Giles, John W. Sear and Pierre Foëx
Nuffield Department of Anaesthetics, University of Oxford, Oxford, OX3 9DU, United Kingdom
Rapid Response:
A response to ‘Beta-blockers for elective surgery in elderly patients: population based, retrospective cohort study’.
EDITOR- Redelmeier and colleagues have presented important evidence on the need to consider the duration of action of beta-blockers in the peri-operative period.1 However, they have failed to recognise two important issues, which may result in the reader of their paper misinterpreting the data they present.
Firstly, when they discuss the potential cardioprotective benefits of peri-operative beta-blockade they refer specifically to acute peri-operative beta-blocker administration.2 Their study design however identifies patients who had beta-blockers administered in the year prior to surgery, assuming that these beta-blockers would be continued into the peri-operative period.1 Their paper therefore describes patients undergoing surgery on chronic (as opposed to acute) beta-blockade. This distinction is vital, as although acute peri-operative beta-blockade may provide peri-operative cardioprotection,3 there is currently no evidence of cardioprotective efficacy of chronic beta-blockade in the peri-operative period.4
This brings us to the second point. Unfortunately, there was no control group consisting of patients who were not on chronic beta-blocker therapy in the peri-operative period. The concern therefore is that although there was a significant difference in outcome between the metoprolol and atenolol patient groups, we do not know how this compares to patients who did not receive peri-operative beta-blockers. Although atenolol was shown to be safer than metoprolol,1 this does not imply that chronic atenolol therapy is cardioprotective in the peri-operative period.4
In various studies, we have been unable to show a difference in a number of postoperative cardiac outcomes between patients who were chronically beta-blocked and patients who were not. There was no difference in postoperative silent myocardial ischaemia,5,6 postoperative troponin I or T release above the upper reference limit,7 30 day mortality,8,9 and 1 year mortality,6 as shown in the Table.
Table 1. Cardiac outcomes in chronically beta-blocked patients undergoing elective surgery
1.00 (0.41-2.44) †
2.07 (0.71-6.08) ††
SMI silent myocardial ischaemia
* unadjusted
† adjusted for calcium channel blockers, history of angina and hypertension
††adjusted for congestive heart failure, left ventricular hypertrophy and nitrate therapy
We must therefore disagree with Redelmeier et al1 in that chronic beta-blockade appears to afford no protection for peri-operative cardiac events. Our observations tally with those of Lee et al10 in the patient cohort in whom they defined the risk factors in their index.
1. Redelmeier D, Scales D, Kopp A. Beta blockers for elective surgery in elderly patients: population based, retrospective cohort study. BMJ 2005;331:932.
2. Auerbach AD, Goldman L. beta-Blockers and reduction of cardiac events in noncardiac surgery: scientific review. JAMA 2002;287:1435-44.
3. Devereaux PJ, Beattie WS, Choi PT, Badner NH, Guyatt GH, Villar JC, et al. How strong is the evidence for the use of perioperative beta blockers in non-cardiac surgery? Systematic review and meta-analysis of randomised controlled trials. BMJ 2005;331:313-21.
4. Giles JW, Sear JW, Foex P. Effect of chronic beta-blockade on peri-operative outcome in patients undergoing non-cardiac surgery: an analysis of observational and case control studies. Anaesthesia 2004;59:574-83.
5. Sear JW, Foex P, Howell SJ. Effect of chronic intercurrent medication with beta-adrenoceptor blockade or calcium channel entry blockade on postoperative silent myocardial ischaemia. Br J Anaesth 2000;84:311-5.
6. Giles JW, Sear JW, Higham H, Sear YM. Chronic beta-adrenoceptor blockade does not reduce incidence of early adverse cardiac outcomes in vascular surgery patients. Br J Anaesth 2003;90:419P.
7. Higham H, Sear JW, Sear YM, Kemp M, Hooper RJ, Foex P. Peri-operative troponin I concentration as a marker of long-term postoperative adverse cardiac outcomes--a study in high-risk surgical patients. Anaesthesia 2004;59:318-23.
8. Sear JW, Howell SJ, Sear YM, Yeates D, Goldacre M, Foex P. Intercurrent drug therapy and perioperative cardiovascular mortality in elective and urgent/emergency surgical patientst. Br J Anaesth 2001;86:506-12.
9. Sear JW, Howell SJ, Sear Y, M., Yeates D, Goldacre M, Foex P. A nested case-control study of risk factors for perioperative cardiovascular death. Br J Anaesth 2001;87:669P.
10. Lee TH, Marcantonio ER, Mangione CM, Thomas EJ, Polanczyk CA, Cook EF, et al. Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery. Circulation 1999;100:1043-9.
Competing interests:
None declared
Competing interests: No competing interests