SPECIAL ARTICLE
Aoric coarctation. te need for lifelong surveillance
J.W.J.
Vriend, B.J.M. Mulder
Survival of patients with aortic coarctation improved dramatically after surgical repair became available and the number of patients who undergo surgery and reach adulthood is steadily increasing. However, life expectancy is still not as normal as in unaffected peers. Cardiovascular complications are frequent and require indefinite follow-up. Concern falls chiefly into five categories: recoarctation, endocarditis, stenotic and/or incompetent coexisting bicuspid aortic valve, aortic aneurysm formation and systemic hypertension. In this review, these complications, with particular reference to late hypertension, are discussed and strategies for the clinical management of postcoarctectomy patients are described. (Neth HeartJ 2003;11: 514-8.) Key words: aortic coarctation, late complications, follow-up, review
foarctation of the thoracic aorta accounts for 5 to O8% of the children with congenital heart defects (figure 1).' Aortic coarctation is frequently accompanied by associated congenital cardiac anomalies. In 59 to 92% of patients with aortic coarctation at least one additional cardiovascular abnormality is present, including bicuspid aortic valve (60 to 80%), aortic arch hypoplasia (33%), patent arterial duct (56%), ventricular septal defect (44%) and subaortic stenosis (18%).2 Without correction, the mean life expectancy of patients with aortic coarctation is 35 years and 90% of these patients die before reaching the age of 50
years.3,4 Survival of patients with aortic coarctation improved dramatically after surgical repair became J.W.J. Vrnd. B.J.M. Mulder. Department of Cardiology, Academic Medical Centre, Meibergdreef 15, 1105 AZ Amsterdam. Address for correspondence: B.J.M. Mulder. E-mail: [email protected]
514
available in 1944. Since then, the number of patients who undergo surgery and reach adulthood is steadily increasing. While the majority of these patients are now reaching adulthood, life expectancy is not as normal as in unaffected peers. Many studies have shown a significant late mortality in postcoarctectomy patients. Survival of patients operated on at a median age of 16 years was 91% at 10 years, 84% at 20 years and 72% at 30 years after operation.5 Survival of postcoarctectomy patients is significantly affected by age at operation and early repair is now advocated.6'7 Even after early repair - before the age of5 years - the estimated survival is still reduced, with 91% of the operated patients alive at 20 years and 79% at 40 years after surgery.4'7 In more than 70% of the patients, late death is the result of a cardiovascular complication.58 So, long-term complications are frequent and require indefinite followup. In this review, we discuss these complications and describe strategies for the long-term management of postcoarctectomy patients. RecoarctatLhn The prevalence of recoarctation varies and is highly dependent on the definition used and the patient's age at repair. Recoarctation is usually defined as the peak-to-peak systolic pressure gradient .20 mmHg at catheterisation.9-11 The risk of recoarctation is significantly increased if surgery is performed at an age less than one year and is most often seen when simple endto-end anastomosis and subclavian flap repair techniques are used (figure 2).4,6,7 Blood pressure differences between arms and legs at rest are easy to determine and have been shown to reflect the severity of narrowing in aortic coarctation and correlate with invasive haemodynamic findings.'2 It is commonly accepted that a resting arm/leg pressure gradient >20 mmHg should prompt further investigation. Echocardiographic Doppler gradients based on the Bernoulli equation are not reliable for detecting residual narrowing of the aorta after aortic coarctation repair.'3 Aortic arch geometry (i.e. hypoplastic arch), complex flow dynamics in the aortic arch, difficulty in closely aligning the Doppler beam with Nctherlands Heart Joumal, Volumc 11, Number 12, December 2003
Aortic coarctation: the need for lifelong surveillance
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flow, and inability to measure flow velocity immediately proximal to the site of the surgical repair with continuous wave Doppler probably relate to this finding.'3'14 At echocardiography the presence and the degree of antegrade diastolic flow (diastolic runoff i.e. 'saw tooth') in the thoracic descending aorta, as noted on spectral Doppler tracings, is considered highly specific for a haemodynamically significant recoarctation (figure 3). The decision to advise catheterbased or surgical intervention for recoarctation should be individualised according to the complexity of the anatomy and presence of associated cardiovascular diseases which warrant reoperation.'5 In experienced hands 'isolated' recoarctation can effectively be treated by balloon angioplasty and stent implantation with a good success rate and safety profile. 1'16"17 Endocarditis In patients after repair of aortic coarctation, endocarditis can occur either at the site of repair or - more often - at an associated abnormal aortic valve. The overall risk of infective endocarditis in the group of operated and nonoperated patients together is moderate to low and appears to increase with age or time after surgery.'8"9 The cumulative incidence of infective Neherands Heart Journal, Volume 11, Number 12, December 2003
Figure 2. MR angiogram of a patient with recoaretation after resection and end-to-end anastomosis. Hypopltic lft subelavian artetyJust distal to the anastomos.
endocarditis in patients after successful surgical repair of aortic coarctation is 0.8±0.4% at one year, slowly increasing to 3.5±1.6% at 30 years of follow-up.8 Aortic aneurysms Aortic aneurysm formation is a well-known complication after repair of aortic coarctation.20'2' Despite primary success, 9% ofpatients develop aortic aneurysms late after operation. The risk seems highest after subclavian flap and patch graft repairs whereas end-toend anastomosis carries the lowest risk of aortic aneurysmal formation (3%) (figure 4).22 Advanced age at coarctation repair, patch graft technique and transverse aortic arch hypoplasia are associated with aortic aneurysm formation.22'23 With the aim to prevent aneurysm development at the site of coarctation ofthe aorta repair, severe limitation of the use of synthetic
515
Aortic coarctation: the need for lifelong surveillance
Figure 4. Large thoracic aorta aneurysm after Dacron patch aortoplasty for aortic coarctation. The left subclavian artery originates from the
aneurysm.
Figure 3. Antegrade diastolicflow in the descending thoracic aorta ('saw tooth'), highly specific for significant (residual) aortic obstruction.
patch aortoplasty is necessary. 2,24 Magnetic resonance imaging is excellent for demonstrating lesions of the descending and ascending aorta. Without MRimaging the diagnosis of aortic arch or descending aortic aneurysms can be easily missed.'5 Bicuspid aortic valve In up to 80% ofthe patients with aortic coarctation, a bicuspid aortic valve is found. The bicuspid aortic valve may function normally throughout life, or it may develop progressive calcification with stenosis or regurgitation. Several studies reported a 9 to 18-fold higher incidence of aortic aneurysms in patients with bicuspid aortic valves.25'26 The bicuspid aortic valve is associated with accelerated degeneration ofthe aortic media, indicating that bicuspid aortic valve disease is an ongoing pathological process, not a discrete developmental event.27 Loss of structural support of the aorta may result in dilation, aneurysms and dissection.27'28 Aortic root replacement is recommended more aggressively for patients with bicuspid aortic valve with aortic dilation than for patients with tricuspid aortic valve. Some authors even advocate prophylactic replacement of the entire aortic root when replacement of an incompetent and/or stenotic bicuspid aortic valve is indicated.29 Late systemic hypertension Even after successful repair of aortic coarctation, patients remain at increased risk of cardiovascular complications and premature death. Coronary artery disease is the most common cause oflate death whereas
heart failure, sudden death, cerebrovascular accidents, endocarditis and rupture of aortic aneurysms are other causes oflate mortality.58 An important contributing factor of this increased risk and a major concern in these patients is the frequently found hypertension. Despite successful surgery for aortic coarctation, the 516
prevalence of hypertension in adults 10 to 20 years after repair is 20 to 40% and is even higher when patients are followed for a longer period of time. Presbitero et al. showed that 30 years after coarctation
repair only 32% of patients were normotensive.8 The most important predictor of premature death and late systemic hypertension is age at the time of initial 68 repair. 8oady early repair, as soon as the diagnosis is made, is advocated. Patients operated on in infancy (
Aoric coarctation. te need for lifelong surveillance
J.W.J.
Vriend, B.J.M. Mulder
Survival of patients with aortic coarctation improved dramatically after surgical repair became available and the number of patients who undergo surgery and reach adulthood is steadily increasing. However, life expectancy is still not as normal as in unaffected peers. Cardiovascular complications are frequent and require indefinite follow-up. Concern falls chiefly into five categories: recoarctation, endocarditis, stenotic and/or incompetent coexisting bicuspid aortic valve, aortic aneurysm formation and systemic hypertension. In this review, these complications, with particular reference to late hypertension, are discussed and strategies for the clinical management of postcoarctectomy patients are described. (Neth HeartJ 2003;11: 514-8.) Key words: aortic coarctation, late complications, follow-up, review
foarctation of the thoracic aorta accounts for 5 to O8% of the children with congenital heart defects (figure 1).' Aortic coarctation is frequently accompanied by associated congenital cardiac anomalies. In 59 to 92% of patients with aortic coarctation at least one additional cardiovascular abnormality is present, including bicuspid aortic valve (60 to 80%), aortic arch hypoplasia (33%), patent arterial duct (56%), ventricular septal defect (44%) and subaortic stenosis (18%).2 Without correction, the mean life expectancy of patients with aortic coarctation is 35 years and 90% of these patients die before reaching the age of 50
years.3,4 Survival of patients with aortic coarctation improved dramatically after surgical repair became J.W.J. Vrnd. B.J.M. Mulder. Department of Cardiology, Academic Medical Centre, Meibergdreef 15, 1105 AZ Amsterdam. Address for correspondence: B.J.M. Mulder. E-mail: [email protected]
514
available in 1944. Since then, the number of patients who undergo surgery and reach adulthood is steadily increasing. While the majority of these patients are now reaching adulthood, life expectancy is not as normal as in unaffected peers. Many studies have shown a significant late mortality in postcoarctectomy patients. Survival of patients operated on at a median age of 16 years was 91% at 10 years, 84% at 20 years and 72% at 30 years after operation.5 Survival of postcoarctectomy patients is significantly affected by age at operation and early repair is now advocated.6'7 Even after early repair - before the age of5 years - the estimated survival is still reduced, with 91% of the operated patients alive at 20 years and 79% at 40 years after surgery.4'7 In more than 70% of the patients, late death is the result of a cardiovascular complication.58 So, long-term complications are frequent and require indefinite followup. In this review, we discuss these complications and describe strategies for the long-term management of postcoarctectomy patients. RecoarctatLhn The prevalence of recoarctation varies and is highly dependent on the definition used and the patient's age at repair. Recoarctation is usually defined as the peak-to-peak systolic pressure gradient .20 mmHg at catheterisation.9-11 The risk of recoarctation is significantly increased if surgery is performed at an age less than one year and is most often seen when simple endto-end anastomosis and subclavian flap repair techniques are used (figure 2).4,6,7 Blood pressure differences between arms and legs at rest are easy to determine and have been shown to reflect the severity of narrowing in aortic coarctation and correlate with invasive haemodynamic findings.'2 It is commonly accepted that a resting arm/leg pressure gradient >20 mmHg should prompt further investigation. Echocardiographic Doppler gradients based on the Bernoulli equation are not reliable for detecting residual narrowing of the aorta after aortic coarctation repair.'3 Aortic arch geometry (i.e. hypoplastic arch), complex flow dynamics in the aortic arch, difficulty in closely aligning the Doppler beam with Nctherlands Heart Joumal, Volumc 11, Number 12, December 2003
Aortic coarctation: the need for lifelong surveillance
_
|
S~~~~~~~~~~~~~~~~~~z
i
Fiur MR anioga of.ain.it otcca abndn colaerl vesk ..
i
wt
flow, and inability to measure flow velocity immediately proximal to the site of the surgical repair with continuous wave Doppler probably relate to this finding.'3'14 At echocardiography the presence and the degree of antegrade diastolic flow (diastolic runoff i.e. 'saw tooth') in the thoracic descending aorta, as noted on spectral Doppler tracings, is considered highly specific for a haemodynamically significant recoarctation (figure 3). The decision to advise catheterbased or surgical intervention for recoarctation should be individualised according to the complexity of the anatomy and presence of associated cardiovascular diseases which warrant reoperation.'5 In experienced hands 'isolated' recoarctation can effectively be treated by balloon angioplasty and stent implantation with a good success rate and safety profile. 1'16"17 Endocarditis In patients after repair of aortic coarctation, endocarditis can occur either at the site of repair or - more often - at an associated abnormal aortic valve. The overall risk of infective endocarditis in the group of operated and nonoperated patients together is moderate to low and appears to increase with age or time after surgery.'8"9 The cumulative incidence of infective Neherands Heart Journal, Volume 11, Number 12, December 2003
Figure 2. MR angiogram of a patient with recoaretation after resection and end-to-end anastomosis. Hypopltic lft subelavian artetyJust distal to the anastomos.
endocarditis in patients after successful surgical repair of aortic coarctation is 0.8±0.4% at one year, slowly increasing to 3.5±1.6% at 30 years of follow-up.8 Aortic aneurysms Aortic aneurysm formation is a well-known complication after repair of aortic coarctation.20'2' Despite primary success, 9% ofpatients develop aortic aneurysms late after operation. The risk seems highest after subclavian flap and patch graft repairs whereas end-toend anastomosis carries the lowest risk of aortic aneurysmal formation (3%) (figure 4).22 Advanced age at coarctation repair, patch graft technique and transverse aortic arch hypoplasia are associated with aortic aneurysm formation.22'23 With the aim to prevent aneurysm development at the site of coarctation ofthe aorta repair, severe limitation of the use of synthetic
515
Aortic coarctation: the need for lifelong surveillance
Figure 4. Large thoracic aorta aneurysm after Dacron patch aortoplasty for aortic coarctation. The left subclavian artery originates from the
aneurysm.
Figure 3. Antegrade diastolicflow in the descending thoracic aorta ('saw tooth'), highly specific for significant (residual) aortic obstruction.
patch aortoplasty is necessary. 2,24 Magnetic resonance imaging is excellent for demonstrating lesions of the descending and ascending aorta. Without MRimaging the diagnosis of aortic arch or descending aortic aneurysms can be easily missed.'5 Bicuspid aortic valve In up to 80% ofthe patients with aortic coarctation, a bicuspid aortic valve is found. The bicuspid aortic valve may function normally throughout life, or it may develop progressive calcification with stenosis or regurgitation. Several studies reported a 9 to 18-fold higher incidence of aortic aneurysms in patients with bicuspid aortic valves.25'26 The bicuspid aortic valve is associated with accelerated degeneration ofthe aortic media, indicating that bicuspid aortic valve disease is an ongoing pathological process, not a discrete developmental event.27 Loss of structural support of the aorta may result in dilation, aneurysms and dissection.27'28 Aortic root replacement is recommended more aggressively for patients with bicuspid aortic valve with aortic dilation than for patients with tricuspid aortic valve. Some authors even advocate prophylactic replacement of the entire aortic root when replacement of an incompetent and/or stenotic bicuspid aortic valve is indicated.29 Late systemic hypertension Even after successful repair of aortic coarctation, patients remain at increased risk of cardiovascular complications and premature death. Coronary artery disease is the most common cause oflate death whereas
heart failure, sudden death, cerebrovascular accidents, endocarditis and rupture of aortic aneurysms are other causes oflate mortality.58 An important contributing factor of this increased risk and a major concern in these patients is the frequently found hypertension. Despite successful surgery for aortic coarctation, the 516
prevalence of hypertension in adults 10 to 20 years after repair is 20 to 40% and is even higher when patients are followed for a longer period of time. Presbitero et al. showed that 30 years after coarctation
repair only 32% of patients were normotensive.8 The most important predictor of premature death and late systemic hypertension is age at the time of initial 68 repair. 8oady early repair, as soon as the diagnosis is made, is advocated. Patients operated on in infancy (
