Downloaded from http://heart.bmj.com/ on November 15, 2015 - Published by group.bmj.com
Editorial
Guidelines is not, and should not be, the Law of the Land Anisha Rastogi, Shahbudin H Rahimtoola Dimarakis et al1 present data from patients aged ≥65 years who had mitral valve replacement (MVR)±coronary artery bypass graft±concomitant tricuspid valve repair from 2001 to 2011. Data are largely from NHS hospitals in England and Wales. There were 3862 patients from 33 hospitals. The three goals of the study and the findings are straightforward: Goal 1 was to determine the per cent of patients in clinical practice in the UK aged ≥65 years who have a mechanical or bioprosthetic mitral prosthetic heart valve (PHV). Approximately 50% received a mechanical and 50% received a bioprosthetic PHV. However, there was considerable variation between hospitals with respect to the choice of PHV. Goal 2 was to establish if the guidelines2 3 are being followed? The two guidelines give a Class II recommendation for use of a bioprosthesis in those aged ≥65 years2 and >70 years.3 This is obviously not being followed in clinical practice. However, there was an increasing trend to use a bioprosthesis with time (28.2% in 2001–2002 to 69.0% in 2010– 2011) and for increasing age (29.6% in those aged 65–70 years to 79% in those aged ≥80 years). Goal 3 was to determine whether the guidelines were appropriate? This was evaluated on the basis of survival outcomes with regard to in-hospital mortality and ‘Mid-Term’ (10-year) survival. With the bioprosthesis and mechanical PHV, the in-hospital mortality in the complete unmatched groups were 7.8% and 5.5%, respectively ( p=0.555) and in the propensity matched groups were 6.9% and 5.9%, respectively ( p=0.355). Considering the patients’ baseline characteristics, these in-hospital mortality results were very good. To evaluate ‘mid-term’ survival, the median follow-up time was 3.9 years (1419 days) and the maximum follow-up time was 10.4 years. In the propensity matched groups, there was no
Division of Cardiovascular Medicine, Department of Medicine, Griffith Center, LAC+USC Medical Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA Correspondence to Dr S H Rahimtoola, University of Southern California, 1200 N. State Street/Old Gen Hosp Rm 3221, Los Angeles, CA 90033, USA; [email protected] Rastogi A, et al. Heart March 2014 Vol 100 No 6
significant difference between the survival curves of patients with the two types of PHVs ( p=0.321) and the unadjusted HR for bioprosthesis was 1.08 (95% CI 0.93 to 1.24). At 3000 days (8.2 years), the survival was almost identical in the two groups (their figure 6). Dimarakis et al have questioned whether it matters that the guidelines were not followed? To answer this question, the study and guidelines have to be further evaluated. Study of Dimarakis: Strength of the study is that it includes the findings from the whole country. The 50% survival at 10 years in both groups is almost identical. This is similar to that in the Edinburgh Heart Valve Trial4 in which the 10-year survival with mechanical valve versus porcine valve was 53% versus 47%, respectively, and in the Department of Veterans Affairs (VA) Trial,5 the survival was almost identical (40%) at 11 years. However, in the study, follow-up time of survival assessment was ‘short’ when compared with the two large randomised trials4 5 and does not allow for appropriate assessment of the effect of MVR on other important outcomes that include structural valve deterioration, thromboembolism, bleeding, anticoagulant therapy and complications associated with their occurrence.6 Guidelines: The strengths of the guidelines are that a number of ‘experts’ contributed to their development which were peer-reviewed by ‘experts’ from the professional societies. The weakness includes age of ≥65 years as a criterion for choice of valves. The VA randomised trial5 had shown that for aortic valve replacement (AVR), the rate of structural valve deterioration for bioprosthesis is statistically significantly lower for those aged ≥65 years. Subsequent data6 show that this is in principle correct but the precise age at which this occurs is very variable for AVR and for MVR and that structural valve deterioration also does occur in the older patient group. The recommendations in the guidelines are based on a mixture of registry data, large and small patient series and ‘expert’ opinions. As a result, the level of evidence C is assigned to almost all the Class II recommendations which make the guidelines a consensus document.
Loscalzo7 has cited a quote which stated “The work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right….” We conclude that (1) more data and studies are needed to provide a more convincing case for a change of the recommendations; (2) Class II recommendation should be interpreted with appropriate caution and wariness, especially if the level of evidence is C and (3) although guidelines matter, they should not be interpreted as being similar to the Law of the Land and subsequent good studies should be encouraged.
CHOICE OF PHV FOR ISOLATED MVR On the basis of the survival data of Dimarakis et al and the two randomised trials for isolated MVR in patients aged ≥65 years, one can choose either a mechanical or bioprosthetic PHV according to the judgement of experienced and skilled clinicians and patient preferences. Other factors also must be considered.6 An important one is whether one wants to avoid the complications associated with the use of mechanical valve (anticoagulants and its complications) or that associated with a bioprosthesis (structural valve deterioration and its complications). Difficulties of frequent monitoring of international normalised ratio can be particularly onerous in the more rural areas and those involving ‘long’ travel times, particularly in the older population. The traditional perception is patients who have atrial fibrillation and are on warfarin therapy, it is better to use a mechanical valve because of the greater durability of the mechanical valve and warfarin therapy would be appropriate for both indications. However, if a patient has bleeding which necessitates discontinuing warfarin, there is risk of thrombosis of the PHV. In the Dimarakis study,1 the incidence of atrial fibrillation was 52%. In the two randomised trials,4 5 the incidence of atrial fibrillation was 55% and 74%, and the incidence of significant bleeding was 10–37% in the porcine valve group and was 53% in the mechanical valve group. In brief, for ‘isolated’ MVR, use of PHV should be individualised and the patient should understand and accept the associated risks and benefits.8 Contributors Both authors contributed to this editorial. Competing interests None. 445
Downloaded from http://heart.bmj.com/ on November 15, 2015 - Published by group.bmj.com
Editorial Provenance and peer review Commissioned; internally peer reviewed.
REFERENCES 1
To cite Rastogi A, Rahimtoola SH. Heart 2014;100:445–446. Received 6 December 2013 Accepted 6 December 2013 Published Online First 6 January 2014
2
3
▸ http://dx.doi.org/10.1136/heartjnl-2013-304783 Heart 2014;100:445–446. doi:10.1136/heartjnl-2013-305280
446
Dimarakis I, Grant SW, Hickey GL, et al. Mitral valve prosthesis choice for patients aged 65 years and over in the UK. Are the guidelines being followed and does it matter? Heart 2014;100:500–7. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2008;118:e523–661. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012): The Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). (Version 2012). Eur Heart J 2012;33:2451–96.
4
5
6
7
8
Oxenham H, Bloomfied P, Wheatley DJ, et al. Twenty year comparison of a Bjork-Shiley mechanical heart valve with porcine bioprostheses. Heart 2003;89:715–21. Hammermeister KE, Sethi GK, Henderson WG, et al. Outcomes 15 years after valve replacement with a mechanical versus bioprosthetic valve: final report of the Veterans Affairs randomized trial. J Am Coll Cardiol 2000;36:1152–8. Rahimtoola SH. Choice of prosthetic heart valve in adults. An update. J Am Coll Cardiol 2010;55:2413–26. Loscalzo J. Irreproducible experimental results. Causes, (mis) interpretations, and consequences. Circulation 2012;125:1211–14. Huang G, Rahimtoola SH. Prosthetic heart valve. Circulation 2011;123:2602–5.
Rastogi A, et al. Heart March 2014 Vol 100 No 6
Downloaded from http://heart.bmj.com/ on November 15, 2015 - Published by group.bmj.com
Guidelines is not, and should not be, the Law of the Land Anisha Rastogi and Shahbudin H Rahimtoola Heart 2014 100: 445-446 originally published online January 6, 2014
doi: 10.1136/heartjnl-2013-305280 Updated information and services can be found at: http://heart.bmj.com/content/100/6/445
These include:
References Email alerting service
Topic Collections
This article cites 7 articles, 5 of which you can access for free at: http://heart.bmj.com/content/100/6/445#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.
Articles on similar topics can be found in the following collections Drugs: cardiovascular system (8469) Epidemiology (3542) Interventional cardiology (2833)
Notes
To request permissions go to: http://group.bmj.com/group/rights-licensing/permissions To order reprints go to: http://journals.bmj.com/cgi/reprintform To subscribe to BMJ go to: http://group.bmj.com/subscribe/
Editorial
Guidelines is not, and should not be, the Law of the Land Anisha Rastogi, Shahbudin H Rahimtoola Dimarakis et al1 present data from patients aged ≥65 years who had mitral valve replacement (MVR)±coronary artery bypass graft±concomitant tricuspid valve repair from 2001 to 2011. Data are largely from NHS hospitals in England and Wales. There were 3862 patients from 33 hospitals. The three goals of the study and the findings are straightforward: Goal 1 was to determine the per cent of patients in clinical practice in the UK aged ≥65 years who have a mechanical or bioprosthetic mitral prosthetic heart valve (PHV). Approximately 50% received a mechanical and 50% received a bioprosthetic PHV. However, there was considerable variation between hospitals with respect to the choice of PHV. Goal 2 was to establish if the guidelines2 3 are being followed? The two guidelines give a Class II recommendation for use of a bioprosthesis in those aged ≥65 years2 and >70 years.3 This is obviously not being followed in clinical practice. However, there was an increasing trend to use a bioprosthesis with time (28.2% in 2001–2002 to 69.0% in 2010– 2011) and for increasing age (29.6% in those aged 65–70 years to 79% in those aged ≥80 years). Goal 3 was to determine whether the guidelines were appropriate? This was evaluated on the basis of survival outcomes with regard to in-hospital mortality and ‘Mid-Term’ (10-year) survival. With the bioprosthesis and mechanical PHV, the in-hospital mortality in the complete unmatched groups were 7.8% and 5.5%, respectively ( p=0.555) and in the propensity matched groups were 6.9% and 5.9%, respectively ( p=0.355). Considering the patients’ baseline characteristics, these in-hospital mortality results were very good. To evaluate ‘mid-term’ survival, the median follow-up time was 3.9 years (1419 days) and the maximum follow-up time was 10.4 years. In the propensity matched groups, there was no
Division of Cardiovascular Medicine, Department of Medicine, Griffith Center, LAC+USC Medical Center, Keck School of Medicine, University of Southern California, Los Angeles, California, USA Correspondence to Dr S H Rahimtoola, University of Southern California, 1200 N. State Street/Old Gen Hosp Rm 3221, Los Angeles, CA 90033, USA; [email protected] Rastogi A, et al. Heart March 2014 Vol 100 No 6
significant difference between the survival curves of patients with the two types of PHVs ( p=0.321) and the unadjusted HR for bioprosthesis was 1.08 (95% CI 0.93 to 1.24). At 3000 days (8.2 years), the survival was almost identical in the two groups (their figure 6). Dimarakis et al have questioned whether it matters that the guidelines were not followed? To answer this question, the study and guidelines have to be further evaluated. Study of Dimarakis: Strength of the study is that it includes the findings from the whole country. The 50% survival at 10 years in both groups is almost identical. This is similar to that in the Edinburgh Heart Valve Trial4 in which the 10-year survival with mechanical valve versus porcine valve was 53% versus 47%, respectively, and in the Department of Veterans Affairs (VA) Trial,5 the survival was almost identical (40%) at 11 years. However, in the study, follow-up time of survival assessment was ‘short’ when compared with the two large randomised trials4 5 and does not allow for appropriate assessment of the effect of MVR on other important outcomes that include structural valve deterioration, thromboembolism, bleeding, anticoagulant therapy and complications associated with their occurrence.6 Guidelines: The strengths of the guidelines are that a number of ‘experts’ contributed to their development which were peer-reviewed by ‘experts’ from the professional societies. The weakness includes age of ≥65 years as a criterion for choice of valves. The VA randomised trial5 had shown that for aortic valve replacement (AVR), the rate of structural valve deterioration for bioprosthesis is statistically significantly lower for those aged ≥65 years. Subsequent data6 show that this is in principle correct but the precise age at which this occurs is very variable for AVR and for MVR and that structural valve deterioration also does occur in the older patient group. The recommendations in the guidelines are based on a mixture of registry data, large and small patient series and ‘expert’ opinions. As a result, the level of evidence C is assigned to almost all the Class II recommendations which make the guidelines a consensus document.
Loscalzo7 has cited a quote which stated “The work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right….” We conclude that (1) more data and studies are needed to provide a more convincing case for a change of the recommendations; (2) Class II recommendation should be interpreted with appropriate caution and wariness, especially if the level of evidence is C and (3) although guidelines matter, they should not be interpreted as being similar to the Law of the Land and subsequent good studies should be encouraged.
CHOICE OF PHV FOR ISOLATED MVR On the basis of the survival data of Dimarakis et al and the two randomised trials for isolated MVR in patients aged ≥65 years, one can choose either a mechanical or bioprosthetic PHV according to the judgement of experienced and skilled clinicians and patient preferences. Other factors also must be considered.6 An important one is whether one wants to avoid the complications associated with the use of mechanical valve (anticoagulants and its complications) or that associated with a bioprosthesis (structural valve deterioration and its complications). Difficulties of frequent monitoring of international normalised ratio can be particularly onerous in the more rural areas and those involving ‘long’ travel times, particularly in the older population. The traditional perception is patients who have atrial fibrillation and are on warfarin therapy, it is better to use a mechanical valve because of the greater durability of the mechanical valve and warfarin therapy would be appropriate for both indications. However, if a patient has bleeding which necessitates discontinuing warfarin, there is risk of thrombosis of the PHV. In the Dimarakis study,1 the incidence of atrial fibrillation was 52%. In the two randomised trials,4 5 the incidence of atrial fibrillation was 55% and 74%, and the incidence of significant bleeding was 10–37% in the porcine valve group and was 53% in the mechanical valve group. In brief, for ‘isolated’ MVR, use of PHV should be individualised and the patient should understand and accept the associated risks and benefits.8 Contributors Both authors contributed to this editorial. Competing interests None. 445
Downloaded from http://heart.bmj.com/ on November 15, 2015 - Published by group.bmj.com
Editorial Provenance and peer review Commissioned; internally peer reviewed.
REFERENCES 1
To cite Rastogi A, Rahimtoola SH. Heart 2014;100:445–446. Received 6 December 2013 Accepted 6 December 2013 Published Online First 6 January 2014
2
3
▸ http://dx.doi.org/10.1136/heartjnl-2013-304783 Heart 2014;100:445–446. doi:10.1136/heartjnl-2013-305280
446
Dimarakis I, Grant SW, Hickey GL, et al. Mitral valve prosthesis choice for patients aged 65 years and over in the UK. Are the guidelines being followed and does it matter? Heart 2014;100:500–7. Bonow RO, Carabello BA, Chatterjee K, et al. 2008 Focused update incorporated into the ACC/AHA 2006 guidelines for the management of patients with valvular heart disease: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation 2008;118:e523–661. Vahanian A, Alfieri O, Andreotti F, et al. Guidelines on the management of valvular heart disease (version 2012): The Joint Task Force on the Management of Valvular Heart Disease of the European Society of Cardiology (ESC) and the European Association for Cardio-Thoracic Surgery (EACTS). (Version 2012). Eur Heart J 2012;33:2451–96.
4
5
6
7
8
Oxenham H, Bloomfied P, Wheatley DJ, et al. Twenty year comparison of a Bjork-Shiley mechanical heart valve with porcine bioprostheses. Heart 2003;89:715–21. Hammermeister KE, Sethi GK, Henderson WG, et al. Outcomes 15 years after valve replacement with a mechanical versus bioprosthetic valve: final report of the Veterans Affairs randomized trial. J Am Coll Cardiol 2000;36:1152–8. Rahimtoola SH. Choice of prosthetic heart valve in adults. An update. J Am Coll Cardiol 2010;55:2413–26. Loscalzo J. Irreproducible experimental results. Causes, (mis) interpretations, and consequences. Circulation 2012;125:1211–14. Huang G, Rahimtoola SH. Prosthetic heart valve. Circulation 2011;123:2602–5.
Rastogi A, et al. Heart March 2014 Vol 100 No 6
Downloaded from http://heart.bmj.com/ on November 15, 2015 - Published by group.bmj.com
Guidelines is not, and should not be, the Law of the Land Anisha Rastogi and Shahbudin H Rahimtoola Heart 2014 100: 445-446 originally published online January 6, 2014
doi: 10.1136/heartjnl-2013-305280 Updated information and services can be found at: http://heart.bmj.com/content/100/6/445
These include:
References Email alerting service
Topic Collections
This article cites 7 articles, 5 of which you can access for free at: http://heart.bmj.com/content/100/6/445#BIBL Receive free email alerts when new articles cite this article. Sign up in the box at the top right corner of the online article.
Articles on similar topics can be found in the following collections Drugs: cardiovascular system (8469) Epidemiology (3542) Interventional cardiology (2833)
Notes
To request permissions go to: http://group.bmj.com/group/rights-licensing/permissions To order reprints go to: http://journals.bmj.com/cgi/reprintform To subscribe to BMJ go to: http://group.bmj.com/subscribe/
