European Heart Journal (1992) 13 (Supplement H), 111-116
Adult congenital heart disease with special reference to the data on long-term follow-up of patients surviving to adulthood with or without surgical correction J. E. DEANFIELD
Cardiothoracic Unit, Hospitalfor Sick Children, Great Ormond Street, London WC1N 3JH KEY WORDS: Aircrew licensing, aviation, adult congenital heart disease, prognosis. complete transposition is an example, with evolution from atrial septectomy, to the Mustard procedure, the The subject of fitness to fly for prospective aircrew with Senning procedure and the currently favoured switch congenital heart disease was considered at the First operation. United Kingdom Workshop in Aviation Cardiology in As technical skills have developed, the age at which 1984[l). Many of the problems in defining risk of serious definitive surgical repair is attempted has progressively morbidity/mortality for both unoperated and operated come down. This has been shown to be associated with congenital heart disease that were highlighted remain, improved long-term results, including preserved ventricudespite new follow-up information covering a further lar function and a lower incidence of late arrhythmia and decade. Nevertheless, during this time both investigation sudden death in some lesions'3'41. All of this contributes and treatment of many lesions (including those common to difficulties in extrapolating risk from published low-risk defects previously recommended as acceptable follow-up data in order to make recommendations for licensing) has changed with the introduction of non- relevant to current medical practice. invasive diagnosis (cross-sectional echocardiography, Long follow-up inevitably means surgery in an earlier Doppler ultrasound, magnetic resonance imaging) and era; more recent surgery must have shorter follow-up. therapeutic cardiac catheterization. This justifies a review MacCartney considered this problem and felt that of recommendations regarding fitness toflyand of approprudence dictated that long follow-up series with their priate strategies for monitoring progress in the light of the 'over pessimistic view' should be the basis for recommennew information on follow-up and changes in medical 1 dation' '. This approach remains sound. With time, practice. Conditions with an event rate less than 1 % per adequate follow-up is becoming available for operations annum for multicrew flights as established by the second resembling those now performed. This should reduce the 121 United Kingdom Workshop in Aviation Cardiology difficulties in interpretation of published data, but will not will be examined. completely eliminate the problem. Introduction
Recommendation for licensing
Rational recommendation about fitness to fly for individuals with congenital heart disease ideally requires a comparison of their risk of major morbid events (e.g. serious arrhythmia, stroke) and sudden death with age/ sex matched controls. This remains difficult for several reasons peculiar to the assessment of congenital heart disease. Firstly, maximum follow-up is still only 37 years, as the era of open-heart surgery began in the early 1950s. For many prospective pilots, this does not yet cover the duration of their potential flying career. Secondly, over this 37 year period, substantial improvements in surgical practice have occurred for almost every congenital heart lesion. This includes improved myocardial protection and bypass technique, better recognition of the intracardiac anatomy (particularly the disposition of the conduction tissues), superior prosthetic materials and the development of new and better operations. The treatment of
Recommendation for licensing requires a minimum of chronic disability together with a defined low risk of sudden incapacity or death. Few of the wide range of congenital heart defects are compatible with survival to adult life fulfilling these requirements without surgery. Surgical 'repair' is now available for many complex defects in childhood and has resulted in a change in the spectrum of adult congenital heart disease over the last decade, with a much higher proportion of repaired 'complex cases'. These often involve the use of prosthetic or homograft valves and extracardiac conduits. Although prosthetic conduits and valves are being continually improved, the 'perfect prosthesis' is still far from a reality and the great majority, if not all, will need eventual replacement. Although survival prospects are good and an acceptable quality of life can now be achieved for the majority of patients with complex defects, none qualify for consideration for licensing as aircrew because of one or more of the following exclusion criteria: (1) highly abnormal residual haemodynamics (including ventricular
Correspondence: Dr J. E. Deanfield, MB MRCP, Consultant Cardiologist and Senior Lecturer, Hospital for Sick Children, Great Ormond Street, London WC1N3JH. 0I95-668X/92/0H0111 +06 $08.00/0
© 1992 The European Society of Cardiology
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on June 7, 2016
Difficulties with recommendation
112
J. E. Deanfield
Atrial septal defect
Atrial septal defects are amongst the most common congenital abnormalities16-71. About 75% are ostium secundum defects, 20% are ostium primum defects (part of the spectrum of atrioventricular septal defects) and 5% are of the sinus venosus type. Defects at other sites are rare'8'. They may be associated with other lesions such as mitral valve prolapse or pulmonary stenosis which bear further consideration in the context of licensing. SECUNDUM DEFECTS
4l'121. As in other series'131, this was largely due to an increased occurrence of supraventricular arrhythmia as a function of age, with a high incidence of fatal cerebrovascular accidents in these patients. The use of the clamshell umbrella to close atrial septal defects without open-heart surgery has obvious attractions and in one series complete closure was reported in 96% of patients without any deaths'"1. Follow-up is short and further development of these devices is required. Catheter closure may become the procedure of choice in selected patients (currently approximately 60% of defects referred are considered appropriate candidates). Patients with small secundum atrial septal defects or atrial septal defects corrected in childhood, who have no evidence of residual haemodynamic abnormality (e.g. normal right ventricular volume and pressure after repair and no evidence of conduction disease or arrhythmia) may be considered for unrestricted licensing although review is desirable on account of the risk of atrial rhythm disturbance. There is no indication for cardiac catheterization either before or after surgery. SINUS VENOSUS DEFECTS
The situation remains less clear for sinus venosus atrial septal defects. There is some evidence that surgery does not reduce risk of arrhythmia and indeed may increase it, although outcome remains excellent'141. It would seem prudent to investigate carefully for the presence of arrhythmia using ambulatory ECG monitoring before licensing is considered and to repeat the procedure annually as part of surveillance. PRIMUM DEFECTS
The situation in ostium primum atrial septal defect is again different as this abnormality is much more complex and inevitably involves the atrioventricular valves (it is part of the spectrum of atrioventricular septal defect). Inadequate information is available to define the risk of late sudden death after repair. There are, however, intrinsic abnormalities of the conduction system both before and after surgery and there is frequently a degree of left atrioventricular valve regurgitation after repair. When significant, this has a powerful adverse effect on survival and the overall actuarial survival of approximately 80% at 10 years indicates a continuing risk in the whole group and a need for caution'151. One could argue the case for corrected patients without left atrioventricular valve regurgitation or residual shunt and normal pulmonary vascular resistance with no evidence of conduction disease or rhythm disturbance to be granted restricted licensing. In this case, annual cross-sectional echocardiography and ambulatory ECG monitoring should be performed to assess the status of the left atrioventricular valve and to monitor for arrhythmia and conduction disturbance.
Survival to adulthood is the rule, but life expectance, without surgery is not normal'61. Mortality after age 40 increases to approximately 6% per year (unconnected)19''01. Morbidity and mortality are due to supraventricular arrhythmia (atrial flutter, atrial fibrillation), deteriorating right ventricular function and later effects on the left ventricle, with the occasional patient developing progressive pulmonary vascular obstructive disease. In small defects, with evidence of a small left-to-right shunt (pulmonary to systemic flow ratio ^1-5:1) and normal right ventricular volume there is no indication for surgery as outlook is excellent, with no risk of sudden death. Transcatheter umbrella closure (see below) may alter the approach to such patients and tip the balance towards intervention, despite the fact that it will be many years before potential benefit might be demonstrated'"1. Closure of significant atrial septal defects should be undertaken early if the long-term outlook is to be acceptable for licensing. In a recent study from the Mayo Clinic of patients undergoing repair between 1956 and 1960, late survival was no worse than the age/sex matched control population for patients undergoing surgery below the age Persistent ductus arteriosus of 24 years, was less good in patients aged 25—41 at surgery An isolated persistent duct is compatible with survival but was poor in those undergoing operation after age into adult life, but it is almost always detected and
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on June 7, 2016
dysfunction), pulmonary hypertension, and residual shunts or outflow tract obstruction any of which may be present even in asymptomatic individuals; (2) the need for chronic cardiovascular medication including anticoagulants; (3) potentially serious arrhythmia such as atrial flutter (e.g. after atrial repair of transposition); ventricular tachycardia (e.g. after ventriculotomy); (4) inadequate follow-up data to define longterm morbidity and mortality. As a result, the number of congenital heart lesions which could currently be reasonably considered for licensing remains low. Little useful information on the risk of sudden death in childhood is available. A cooperative international study of 254 pre- and postoperative cases published in 1974 is of limited value as it is anecdotal and does not provide the necessary 'risk' information'51. Current knowledge suggests that certain minor unoperated defects (e.g. small atrial septal defect and ventricular septal defects as discussed below) could be considered for licensing whereas in others, repair will almost always have to have been performed in childhood and be a prerequisite for potential licensing (e.g. coarctation of the aorta; tetralogy of Fallot).
Adult congenital heart disease
closed in childhood. This is currently recommended for all persistent ducts regardless of size because of the reduced risk of infective endocarditis after surgery and the extremely low surgical risk. It is now possible to close selected persistent ducts with a catheter-mounted umbrella device1161. There has been a learning curve for this procedure with progressively improving complete closure rates which now approach those obtained by surgery. The long-term risk of endocarditis after this procedure is unknown, but in the short and medium follow-up now available, it appears to be low and antibiotic prophylaxis after one year is not currently recommended. Providing there is no evidence of pulmonary vascular obstructive disease it seems reasonable to grant unrestricted licensing. The presence of associated cardiac defects such as pulmonary valve stenosis, bicuspid aortic valve or subaortic stenosis will dictate suitability of the licensing over and above the persistent duct itself and its management.
Although coarctation of the aorta is a congenital defect and is usually picked up in childhood, up to 20% of cases are first diagnosed in adolescence or adulthood. The natural history is poor and in almost all cases upper limb hypertension mandates repair. The Mayo Clinic has published late results in 646 patients who underwent surgery between 1946 and 1981, at a median age of 16 years1171. Overall survival was 91% at 10 years, 84% at 20 years and 72% at 30 years with a mean age at death of 38 years. Three main points emerged from this study. (1) The age at repair was the most important predictor of long-term survival—for patients aged 14 years or less at operation, 20 year survival was 91% vs 79% for patients aged 14 years or more. The best survival rates were found in patients operated below the age of 9 years. (2) Age at repair was the most important predictor of hypertension and the higher the postoperative systolic blood pressure the higher the probability of death. (3) In order of importance, coronary artery disease, sudden cardiac death, heart failure, cerebrovascular accident and aortic aneurysm rupture were the commonest causes of death with a sudden death rate of 11 in 11 142 patient years or 0-1 % over the whole follow-up period. The study of Presbitero et al. on 226 patients who underwent surgery between 1954 and 1969 also emphasized the importance of early repair on late results'181. In their series, actuarial survival for patients operated on between 4 and 20 years of age was 92% at 30 years after surgery and was not significantly different from that of a comparable general Italian population. Only two patients died suddenly, a rate of 005% per patient year. Despite the low risk of sudden death, both series emphasized the high incidence of late hypertension, premature coronary artery disease and potential complications from associated cardiac defects such as bicuspid aortic valve (present in up to one third of patients with coarctation). Late problems including sudden death were almost always confined to patients with persistent hypertension.
In the light of these findings, it seems reasonable to consider for full licensing, subjects who have undergone repair aged less than 14 years with no associated cardiac defects, with no residual coarctation (arm and leg blood pressure difference) and who are normotensive at rest and on exercise. Restricted licensing could be considered for those operated upon at an older age, provided they were normotensive. Careful follow-up, including monitoring of blood pressure and search for premature coronary artery disease, is indicated in all patients. Ventricular septal defect
Isolated ventricular septal defect is one of the commonest congenital heart abnormalities in children but is much less common in adults'61 as: (1) most patients with large ventricular septal defects either die in childhood or (2) develop pulmonary vascular obstructive disease and die prematurely as adults; (3) most undergo surgical closure in childhood'191 or (4) undergo spontaneous closure. The spectrum of ventricular septal defect in adults thus consists largely of individuals with small defects, patients with Eisenmenger's Syndrome, and postoperative patients. Individuals with a small ventricular septal defect and small left-to-right shunt (pulmonary to systemic flow ratio
Adult congenital heart disease with special reference to the data on long-term follow-up of patients surviving to adulthood with or without surgical correction J. E. DEANFIELD
Cardiothoracic Unit, Hospitalfor Sick Children, Great Ormond Street, London WC1N 3JH KEY WORDS: Aircrew licensing, aviation, adult congenital heart disease, prognosis. complete transposition is an example, with evolution from atrial septectomy, to the Mustard procedure, the The subject of fitness to fly for prospective aircrew with Senning procedure and the currently favoured switch congenital heart disease was considered at the First operation. United Kingdom Workshop in Aviation Cardiology in As technical skills have developed, the age at which 1984[l). Many of the problems in defining risk of serious definitive surgical repair is attempted has progressively morbidity/mortality for both unoperated and operated come down. This has been shown to be associated with congenital heart disease that were highlighted remain, improved long-term results, including preserved ventricudespite new follow-up information covering a further lar function and a lower incidence of late arrhythmia and decade. Nevertheless, during this time both investigation sudden death in some lesions'3'41. All of this contributes and treatment of many lesions (including those common to difficulties in extrapolating risk from published low-risk defects previously recommended as acceptable follow-up data in order to make recommendations for licensing) has changed with the introduction of non- relevant to current medical practice. invasive diagnosis (cross-sectional echocardiography, Long follow-up inevitably means surgery in an earlier Doppler ultrasound, magnetic resonance imaging) and era; more recent surgery must have shorter follow-up. therapeutic cardiac catheterization. This justifies a review MacCartney considered this problem and felt that of recommendations regarding fitness toflyand of approprudence dictated that long follow-up series with their priate strategies for monitoring progress in the light of the 'over pessimistic view' should be the basis for recommennew information on follow-up and changes in medical 1 dation' '. This approach remains sound. With time, practice. Conditions with an event rate less than 1 % per adequate follow-up is becoming available for operations annum for multicrew flights as established by the second resembling those now performed. This should reduce the 121 United Kingdom Workshop in Aviation Cardiology difficulties in interpretation of published data, but will not will be examined. completely eliminate the problem. Introduction
Recommendation for licensing
Rational recommendation about fitness to fly for individuals with congenital heart disease ideally requires a comparison of their risk of major morbid events (e.g. serious arrhythmia, stroke) and sudden death with age/ sex matched controls. This remains difficult for several reasons peculiar to the assessment of congenital heart disease. Firstly, maximum follow-up is still only 37 years, as the era of open-heart surgery began in the early 1950s. For many prospective pilots, this does not yet cover the duration of their potential flying career. Secondly, over this 37 year period, substantial improvements in surgical practice have occurred for almost every congenital heart lesion. This includes improved myocardial protection and bypass technique, better recognition of the intracardiac anatomy (particularly the disposition of the conduction tissues), superior prosthetic materials and the development of new and better operations. The treatment of
Recommendation for licensing requires a minimum of chronic disability together with a defined low risk of sudden incapacity or death. Few of the wide range of congenital heart defects are compatible with survival to adult life fulfilling these requirements without surgery. Surgical 'repair' is now available for many complex defects in childhood and has resulted in a change in the spectrum of adult congenital heart disease over the last decade, with a much higher proportion of repaired 'complex cases'. These often involve the use of prosthetic or homograft valves and extracardiac conduits. Although prosthetic conduits and valves are being continually improved, the 'perfect prosthesis' is still far from a reality and the great majority, if not all, will need eventual replacement. Although survival prospects are good and an acceptable quality of life can now be achieved for the majority of patients with complex defects, none qualify for consideration for licensing as aircrew because of one or more of the following exclusion criteria: (1) highly abnormal residual haemodynamics (including ventricular
Correspondence: Dr J. E. Deanfield, MB MRCP, Consultant Cardiologist and Senior Lecturer, Hospital for Sick Children, Great Ormond Street, London WC1N3JH. 0I95-668X/92/0H0111 +06 $08.00/0
© 1992 The European Society of Cardiology
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on June 7, 2016
Difficulties with recommendation
112
J. E. Deanfield
Atrial septal defect
Atrial septal defects are amongst the most common congenital abnormalities16-71. About 75% are ostium secundum defects, 20% are ostium primum defects (part of the spectrum of atrioventricular septal defects) and 5% are of the sinus venosus type. Defects at other sites are rare'8'. They may be associated with other lesions such as mitral valve prolapse or pulmonary stenosis which bear further consideration in the context of licensing. SECUNDUM DEFECTS
4l'121. As in other series'131, this was largely due to an increased occurrence of supraventricular arrhythmia as a function of age, with a high incidence of fatal cerebrovascular accidents in these patients. The use of the clamshell umbrella to close atrial septal defects without open-heart surgery has obvious attractions and in one series complete closure was reported in 96% of patients without any deaths'"1. Follow-up is short and further development of these devices is required. Catheter closure may become the procedure of choice in selected patients (currently approximately 60% of defects referred are considered appropriate candidates). Patients with small secundum atrial septal defects or atrial septal defects corrected in childhood, who have no evidence of residual haemodynamic abnormality (e.g. normal right ventricular volume and pressure after repair and no evidence of conduction disease or arrhythmia) may be considered for unrestricted licensing although review is desirable on account of the risk of atrial rhythm disturbance. There is no indication for cardiac catheterization either before or after surgery. SINUS VENOSUS DEFECTS
The situation remains less clear for sinus venosus atrial septal defects. There is some evidence that surgery does not reduce risk of arrhythmia and indeed may increase it, although outcome remains excellent'141. It would seem prudent to investigate carefully for the presence of arrhythmia using ambulatory ECG monitoring before licensing is considered and to repeat the procedure annually as part of surveillance. PRIMUM DEFECTS
The situation in ostium primum atrial septal defect is again different as this abnormality is much more complex and inevitably involves the atrioventricular valves (it is part of the spectrum of atrioventricular septal defect). Inadequate information is available to define the risk of late sudden death after repair. There are, however, intrinsic abnormalities of the conduction system both before and after surgery and there is frequently a degree of left atrioventricular valve regurgitation after repair. When significant, this has a powerful adverse effect on survival and the overall actuarial survival of approximately 80% at 10 years indicates a continuing risk in the whole group and a need for caution'151. One could argue the case for corrected patients without left atrioventricular valve regurgitation or residual shunt and normal pulmonary vascular resistance with no evidence of conduction disease or rhythm disturbance to be granted restricted licensing. In this case, annual cross-sectional echocardiography and ambulatory ECG monitoring should be performed to assess the status of the left atrioventricular valve and to monitor for arrhythmia and conduction disturbance.
Survival to adulthood is the rule, but life expectance, without surgery is not normal'61. Mortality after age 40 increases to approximately 6% per year (unconnected)19''01. Morbidity and mortality are due to supraventricular arrhythmia (atrial flutter, atrial fibrillation), deteriorating right ventricular function and later effects on the left ventricle, with the occasional patient developing progressive pulmonary vascular obstructive disease. In small defects, with evidence of a small left-to-right shunt (pulmonary to systemic flow ratio ^1-5:1) and normal right ventricular volume there is no indication for surgery as outlook is excellent, with no risk of sudden death. Transcatheter umbrella closure (see below) may alter the approach to such patients and tip the balance towards intervention, despite the fact that it will be many years before potential benefit might be demonstrated'"1. Closure of significant atrial septal defects should be undertaken early if the long-term outlook is to be acceptable for licensing. In a recent study from the Mayo Clinic of patients undergoing repair between 1956 and 1960, late survival was no worse than the age/sex matched control population for patients undergoing surgery below the age Persistent ductus arteriosus of 24 years, was less good in patients aged 25—41 at surgery An isolated persistent duct is compatible with survival but was poor in those undergoing operation after age into adult life, but it is almost always detected and
Downloaded from http://eurheartj.oxfordjournals.org/ by guest on June 7, 2016
dysfunction), pulmonary hypertension, and residual shunts or outflow tract obstruction any of which may be present even in asymptomatic individuals; (2) the need for chronic cardiovascular medication including anticoagulants; (3) potentially serious arrhythmia such as atrial flutter (e.g. after atrial repair of transposition); ventricular tachycardia (e.g. after ventriculotomy); (4) inadequate follow-up data to define longterm morbidity and mortality. As a result, the number of congenital heart lesions which could currently be reasonably considered for licensing remains low. Little useful information on the risk of sudden death in childhood is available. A cooperative international study of 254 pre- and postoperative cases published in 1974 is of limited value as it is anecdotal and does not provide the necessary 'risk' information'51. Current knowledge suggests that certain minor unoperated defects (e.g. small atrial septal defect and ventricular septal defects as discussed below) could be considered for licensing whereas in others, repair will almost always have to have been performed in childhood and be a prerequisite for potential licensing (e.g. coarctation of the aorta; tetralogy of Fallot).
Adult congenital heart disease
closed in childhood. This is currently recommended for all persistent ducts regardless of size because of the reduced risk of infective endocarditis after surgery and the extremely low surgical risk. It is now possible to close selected persistent ducts with a catheter-mounted umbrella device1161. There has been a learning curve for this procedure with progressively improving complete closure rates which now approach those obtained by surgery. The long-term risk of endocarditis after this procedure is unknown, but in the short and medium follow-up now available, it appears to be low and antibiotic prophylaxis after one year is not currently recommended. Providing there is no evidence of pulmonary vascular obstructive disease it seems reasonable to grant unrestricted licensing. The presence of associated cardiac defects such as pulmonary valve stenosis, bicuspid aortic valve or subaortic stenosis will dictate suitability of the licensing over and above the persistent duct itself and its management.
Although coarctation of the aorta is a congenital defect and is usually picked up in childhood, up to 20% of cases are first diagnosed in adolescence or adulthood. The natural history is poor and in almost all cases upper limb hypertension mandates repair. The Mayo Clinic has published late results in 646 patients who underwent surgery between 1946 and 1981, at a median age of 16 years1171. Overall survival was 91% at 10 years, 84% at 20 years and 72% at 30 years with a mean age at death of 38 years. Three main points emerged from this study. (1) The age at repair was the most important predictor of long-term survival—for patients aged 14 years or less at operation, 20 year survival was 91% vs 79% for patients aged 14 years or more. The best survival rates were found in patients operated below the age of 9 years. (2) Age at repair was the most important predictor of hypertension and the higher the postoperative systolic blood pressure the higher the probability of death. (3) In order of importance, coronary artery disease, sudden cardiac death, heart failure, cerebrovascular accident and aortic aneurysm rupture were the commonest causes of death with a sudden death rate of 11 in 11 142 patient years or 0-1 % over the whole follow-up period. The study of Presbitero et al. on 226 patients who underwent surgery between 1954 and 1969 also emphasized the importance of early repair on late results'181. In their series, actuarial survival for patients operated on between 4 and 20 years of age was 92% at 30 years after surgery and was not significantly different from that of a comparable general Italian population. Only two patients died suddenly, a rate of 005% per patient year. Despite the low risk of sudden death, both series emphasized the high incidence of late hypertension, premature coronary artery disease and potential complications from associated cardiac defects such as bicuspid aortic valve (present in up to one third of patients with coarctation). Late problems including sudden death were almost always confined to patients with persistent hypertension.
In the light of these findings, it seems reasonable to consider for full licensing, subjects who have undergone repair aged less than 14 years with no associated cardiac defects, with no residual coarctation (arm and leg blood pressure difference) and who are normotensive at rest and on exercise. Restricted licensing could be considered for those operated upon at an older age, provided they were normotensive. Careful follow-up, including monitoring of blood pressure and search for premature coronary artery disease, is indicated in all patients. Ventricular septal defect
Isolated ventricular septal defect is one of the commonest congenital heart abnormalities in children but is much less common in adults'61 as: (1) most patients with large ventricular septal defects either die in childhood or (2) develop pulmonary vascular obstructive disease and die prematurely as adults; (3) most undergo surgical closure in childhood'191 or (4) undergo spontaneous closure. The spectrum of ventricular septal defect in adults thus consists largely of individuals with small defects, patients with Eisenmenger's Syndrome, and postoperative patients. Individuals with a small ventricular septal defect and small left-to-right shunt (pulmonary to systemic flow ratio
