An extraordinary survival at the age of 67 years in an unoperated case tetralogy of Fallot presenting as systemic hypertension despite RV dysfunction

Abstract

Tetralogy of Fallot is a cyanotic congenital heart disease characterised by a tetrad of four anomalies including ventricular septal defect, pulmonary stenosis, over-riding of aorta and right ventricular hypertrophy with high incidence of infant and early childhood mortality with middle age survival less than 5%. Most cases require treatment in infancy and are symptomatic early on. Rare cases of survival to middle age have been reported especially after the fourth decade. We report an unoperated case of tetralogy of Fallot diagnosed at the age of 67 which is one of the longest time periods of diagnosis of a life-threatening congenital heart disease. Despite tetralogy and having right ventricular dysfunction manifested in the form of congestive symptoms, this patient presented with systemic hypertension along with cyanosis and clubbing which is considered to be a relatively rare presentation in this syndrome. The patient wished to be managed conservatively.

Background

Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart disease in childhood but rarely seen in adulthood. In 1888 Fallot published a detailed description of this entity for the first time which is characterised by the presence of four anatomic components of right-ventricular outflow tract (RVOT) obstruction, outlet ventricular septal defect, over-riding of aorta and right-ventricular hypertrophy. TOF results from specific morphological abnormality which arises due to the anterocephalad displacement of infundibular septum which leads to the development of infundibular pulmonary stenosis and thereby right-ventricular hypertrophy. Other cardiac and extracardiac abnormalities which include anomalies such as right-sided aortic arch, anomalous coronary anatomy, multiple ventricular septal defects, atrial septal defect and persistent ductus arteriosus may also be observed in as many as 40% of patients.¹ Survival in unoperative TOF over the fourth decade is <3% but occasionally can reach older ages. In this case report, we present an elderly patient who was diagnosed at the age of 67 to have TOF with systemic hypertension. Considering patient’s comorbid conditions and risk associated with the surgery and complying to the patient’s desire of going for a conservative therapy, we decided to manage medically. To our knowledge, this is one of the oldest unoperated TOF cases reported and the presentation with systemic hypertension makes this case unique and makes this case an eye opener for the clinicians who presume that most patients presenting with cyanosis after middle age are usually because of Eisenmenger’s syndrome or secondary to respiratory pathology. This case also illustrates the value of a diagnostic echocardiogram in patients presenting with cyanosis and clubbing to assess for causes leading to decreased pulmonary blood flow.

Case presentation

A 67-year-old man was admitted to our hospital with swelling in legs, fatigue and exertional dyspnoea New York Heart Association (NYHA) II, progressed to NYHA III in the past 2 years. On biochemical analyses haemoglobin was 17.4 g/dL, and packed cell volume was 58%, serum creatinine was 1 mg/dL. On general physical examination, the patient was cyanotic with oxygen saturation of 80% at rest. Bilateral digital clubbing was present in all limbs and pedal oedema in both lower limbs. Pulse rate was 76/min, regular, normovolumic. Blood pressure was 174/94 mm Hg. On cardiac examination precordium was relatively silent. On auscultation second heart sound was single. A systolic ejection murmur was heard in left second intercostal space.

Investigations

ECG showed sinus rhythm, right-axis deviation, R wave transition in lead V2, right ventricular (RV) hypertrophy, chest radiography showed cardiothoracic ratio of 0.55, RV type apex and low-to-normal pulmonary vascularity, left aortic arch. Two-dimensional echocardiography showed biventricular hypertrophy, large subaortic ventricular septal defect, over-riding of the aorta and severe infundibular stenosis with a peak gradient of 100 mm Hg with RV dysfunction (figures 1 and 2). The presence of RV dysfunction was assessed visually and on the basis of conventional parameters like TAPSE which was 13 in this case.

Figure 1.

Two-dimensional echocardiogram showing large subaortic ventricular septal defect with bidirectional shunt and right ventricular hypertrophy.

Figure 2.

Continuous wave Doppler across right ventricular outflow tract in parasternal short-axis view showing a gradient of 100 mm Hg.

Cardiac CT scan was carried out. Findings suggested narrow RVOT with RV hypertrophy and aortopulmonary collaterals (figures 3 and 4).

Figure 3.

CT angiogram showing multiple aortopulmonary collaterals.

Figure 4.

CT angiogram showing multiple aortopulmonary collaterals.

Differential diagnosis

The differential diagnosis in this case which was considered initially included Eisenmenger's syndrome which was excluded clinically on the basis of the history and the presence of soft pulmonary component which was later confirmed echocardiographically. Respiratory causes of cyanosis and malignant causes of clubbing were also excluded on the basis of clinical evaluation which was confirmed echocardiographically.

Treatment

The patient was not willing for surgical correction in view of his age and fragile status after having being explained about the surgical risk and the controversial data available on the long-term prognosis and the risk of sudden cardiac death. There was dilemma about the antihypertensive drugs which should be used in this case as vasodilators are usually avoided in cases of low-cardiac output and stenotic lesions and β-blocker could not be used immediately as the patient was not euvolemic. The patient was treated conservatively for congestive cardiac failure with furosemide, spironolactone and was given ACE inhibitors for hypertension.

Outcome and follow-up

The patient was stable at 3 months of follow-up with attainment of euvolemic status and appropriate control of hypertension and was started on carvedilol (β-blocker) for heart failure and better hypertension control and also to reduce the risk of sudden cardiac death.

Discussion

TOF is a disease which usually presents in infancy and early childhood with rare cases presenting after adolescence and middle age. The likelihood of this disease being undetected for a long term is less likely considering the multiple systemic manifestations of the disease. Rare cases may go undetected in rural areas of developing and underdeveloped countries where the healthcare system is still backward and access to basic medical services is still lacking. Survival rates of unoperated patients with TOF older than 10 years range between 25% and 30%, while the reported survival rates after 20 years range between 10% and 12%, and in age above 30 years the rate of survival is around 6%, and in older than 40 years only about 3% of patients are seen to survive.² There have been case reports of prolonged survival in unoperated cases, but most of them had been diagnosed earlier and none of them have been reported to present with hypertension.^3–7 One of the cases has reported hypertension in a child with TOF⁸ but an adult or elderly patient presenting with hypertension has not been reported previously. Progression of the disease in TOF is mainly determined by degree of pulmonary obstruction and pulmonary blood supply. When resistance to flow in the RVOT exceeds that of the aorta, right-to-left shunting occur which leads to the development of cyanosis and thereby leads to early diagnosis of most of the cases.

If resistance in the RVOT is less than that in the aorta, there will be a left-to-right shunt across the ventricular septal defect without peripheral cyanosis (Pink TOF). The incidence of acyanotic TOF has been reported to be around 5% among patients with TOF.⁹ Total correction of TOF is preferred by 1–2 years of life with most of the studies showing decreased survival and increased risk of sudden cardiac death in cases where surgery is delayed. Survival rate of corrective operations is 94% over 25 years.¹⁰ However, sudden cardiac death due to malignant ventricular arrhythmias originating from ventricular septal patches or from the site of surgical scar can occur during the course of follow-up and can lead to decreased survival.⁹

Improved survival in unoperated patients has been attributed to the presence of an extracardiac shunt, like patent ductus arteriosus, which may contribute as an additional source of blood supply to the pulmonary circulation.¹¹ Another reason is the development of left ventricular hypertrophy that occurs in some cases with prolonged survival, which may act as a balancing factor in the degree of interventricular shunting and could decrease the amount of a right-to-left shunt.¹² In our case, echocardiography showed left ventricular hypertrophy due to the presence of systemic hypertension which was seen in this case, but there was no extracardiac shunt. In a previous study in which 30 patients with TOF underwent total correction at the ages of 40–60 years, operative mortality was found as 3%, whereas survival was 92% at 5 years and 74% at 10 years.¹³ In our case, we decided to manage medically complying to the wish of the patient and also because there is inadequate data to support surgery at this age, especially in the presence of overt RV dysfunction.

Learning points.

• Albeit extremely rare, some patients with tetralogy of Fallot, especially cases which had been initially acyanotic, can reach older ages without operation. To the best of our knowledge, this is one of the oldest unoperated cases reported which makes it important for a meticulous echocardiographic examination to differentiate cyanotic patients from respiratory and Eisenmenger's syndrome.

• Systemic hypertension due to arteriosclerosis can be seen in cases where tetralogy is detected in elderly patients who can be present despite the presence of haemodynamically significant right ventricular dysfunction. The therapy in these patients is controversial and drugs such as ACE inhibitors, diuretics and β-blockers may be tried.

• The role of surgical management in elderly patients is controversial and surgical correction may be considered although the overall survival is significantly reduced even after successful surgery. Long-term prognosis is poor and the risk of sudden cardiac death continues to be present especially in the presence of significant dysfunction of the right ventricle.