Samuel Siu

Arrhythmia and survival in patients>18 years of age after the Mustard procedure for complete transposition of the great arteries

Increasing numbers of patients who underwent Mustard repair as children are now adults. Loss of sinus rhythm, supraventricular arrhythmias, and sudden death have been described in pediatric series. However, little is known about the clinical course of adult patients. This retrospective cohort study examined 86 consecutive adults (age >18 years) who had undergone the Mustard procedure and were referred to an adult congenital cardiac clinic for ongoing follow-up. The incidence and predictors of arrhythmia, congestive heart failure, and death were determined. The median follow-up period was 8 years after age 18 or 23 years after Mustard repair. There were 8 deaths (9%), 2 were sudden. Congestive heart failure (CHF) requiring hospital admission occurred in 9 patients (10%). Pulmonary hypertension and systemic ventricular dysfunction were independent risk factors for death or CHF. Only 29 patients (34%) remained arrhythmia-free. Forty-one patients (48%) had at least 1 episode of supraventricular tachycardia (SVT), with most patients (30, 73%) having atrial flutter. SVT after the age of 18 was associated with CHF. Pulmonary hypertension, systemic ventricular dysfunction, and junctional rhythm before age 18 were independent risk factors for SVT. Pacemakers were implanted in 19 patients (22%); 13 of those were beyond age 18. Thus, adult survivors of the Mustard procedure continue to be at risk for premature death, CHF and supraventricular tachyarrhythmia.

Angiotensin-Converting Enzyme Inhibitors in Adults After the Mustard Procedure

Angiotensin-converting enzyme inhibitors had no significant effect on cardiopulmonary exercise function in 14 patients who had undergone a Mustard operation for transposition of the great arteries. In some patients aerobic capacity improved and maximum systolic blood pressure decreased.

Outpatient clinics for adults with congenital heart disease: increasing workload and evolving patterns of referral.

Objective To examine the evolving role of specialised outpatient services for adult patients with congenital heart disease. Design A retrospective analysis of all patients attending the Toronto Congenital Cardiac Centre for Adults over three corresponding three month periods in 1987, 1992, and 1997. Setting A tertiary referral centre. Main outcome measures Patient demographics, residence, medical and surgical history, type and source of referral, and investigations performed. Results In all, 570 patients were seen at the clinic during these three periods. There was a 44% and a 269% increase in workload between 1987 to 1992 and 1992 to 1997, respectively. There was a steady fall in mean age of patients seen at the clinic with time (38.5, 33.6, and 31.7 years in 1987, 1992, and 1997, respectively, p < 0.001). New referrals from community cardiologists and family physicians increased more in relative terms than did referrals from the Hospital for Sick Children, Toronto (6.7%, 15%, and 37.5%, p = 0.02). There was a steady increase in patients with previous reparative surgery (48.9%, 59.2%, and 69.2%, p < 0.002). The proportion of patients with previous reoperations also increased (2.3%, 10%, and 9.2%, p < 0.01). Echocardiography remained the predominant method of diagnosis. The diagnostic mix did not change with time. Conclusions Over the past 10 years there has been a large increase in adults with congenital heart disease requiring and seeking specialised care in a tertiary health centre, with a concomitant evolution of referral patterns. These data may be helpful in planning of similar paediatric and adult cardiac services for this expanding population.

Symptomatic atrial arrhythmias and transcatheter closure of atrial septal defects in adult patients

Objective: To determine whether transcatheter device closure of a secundum atrial septal defect (ASD) will reduce the risk of developing subsequent atrial arrhythmias. Design: The incidence and predictors of symptomatic atrial tachyarrhythmias (AT) were examined in adults undergoing transcatheter closure of ASDs. Setting: Toronto Congenital Cardiac Centre for Adults. Patients: 132 consecutive patients, mean (SD) age 44 (16) years; 74% female. Main outcome measure: Sustained or symptomatic atrial arrhythmias at early follow up (six weeks; n  =  115) and intermediate follow up (last clinic visit 17 (11) months post surgery; n  =  121). Results: 15% of the patients (20 of 132) had AT before the procedure (14 paroxysmal, six persistent). Patients without a history of arrhythmia had a low incidence of AT during early follow up (6%) and intermediate follow up (1%/year), while all patients with persistent AT before closure remained in atrial fibrillation or flutter. Of patients in sinus rhythm but with a previous history of AT, two thirds remained arrhythmia-free at follow up, with overall incidences of paroxysmal and persistent AT of 17%/year and 11%/year. A history of AT before closure (risk ratio (RR) 35.0, 95% confidence interval (CI) 7.2 to 169.0) and age ⩾ 55 years at the time of device insertion (RR 5.6, 95% CI 1.2 to 25.0) predicted AT after closure. Conclusions: Device closure of an ASD before the onset of atrial arrhythmias may protect against the subsequent development of arrhythmia, in particular in patients less than 55 years of age.

Outcomes in patients with pulmonary hypertension undergoing percutaneous atrial septal defect closure

Objectives: To examine the outcomes in patients with moderate or severe pulmonary arterial hypertension (PAH) undergoing percutaneous atrial septal defect (ASD) closure. Design: Retrospective study. Setting: Teaching hospital-based study. Patients: Fifty-four patients with moderate (n = 34) or severe PAH (n = 20) who underwent successful device implantation between 1999 and 2004 were included in the study. Clinical and transthoracic echocardiographic data were reviewed. Pulmonary hypertension was classified as moderate (50–59 mm Hg) or severe (⩾60 mm Hg) according with the right ventricular systolic pressure (RVSP) calculated by echocardiography. Results: At the early follow-up (mean (SD) 2.3 (1.2) months) all patients were alive and the baseline RVSP decreased from 57 (11) mm Hg to 51 (17) mm Hg (p = 0.003). At the late follow-up (n = 39, mean (SD) duration 31 (15) months) two patients had died and the baseline RVSP decreased from 58 (10) mm Hg to 44 (16) mm Hg (p = 0.004). Although the overall mean RVSP decreased at late follow-up, only 43.6% (17/39) of patients had normalisation (<40 mm Hg) of the RVSP and 15.4% (6/39) had persistent severe PAH. Conclusion: Transcatheter closure in patients with secundum ASD and PAH can be successfully performed in selected subjects and is associated with good outcomes. Early improvements in RVSP are seen in patients with moderate or severe PAH undergoing transcatheter ASD closure. Continued improvement in RVSP occurs in late follow-up. Despite decreases in the mean RVSP in late follow-up, many patients do not have complete normalisation of pressures.

Lung function and aerobic capacity in adult patients following modified Fontan procedure

OBJECTIVE To examine cardiopulmonary performance in 52 adult patients with a Fontan circulation. DESIGN Retrospective cohort study. Values of maximum oxygen uptake (Vo 2max), maximum heart rate (HRmax), forced vital capacity (FVC), and forced expiratory volume in one second (FEV1) were compared with predictive values for different age groups. Patients were further subdivided into those with a pulmonary artery connection (RA–PA) or right atrium to right ventricle conduit (RA–RV). RESULTS At late follow up (median 10 years, range 1 to 26 years), patients with Fontan circulation had greatly diminished Vo 2max, HRmax, FVC, and FEV1 compared with predicted values. Early age at surgery had a positive impact on aerobic capacity. The FEV1:FVC ratio indicated restrictive lung function. No differences were found with respect to any variable between patients with RA–PA connections and those with RA–RV connections. CONCLUSIONS Patients with a Fontan circulation have greatly diminished values of aerobic capacity and a restrictive pattern of lung function. Patients with an early surgical procedure obtained higher values of Vo 2max. The theoretical benefits of including the right ventricle in a Fontan circulation were not apparent.

The Fontan procedure in adults

SETTING Tertiary adult congenital cardiac referral centre. DESIGN Retrospective cross sectional analysis. OBJECTIVES To report our 20 year experience with adult Fontan operations, and to compare late outcome in patients with single ventricle with definitive aortopulmonary or cavopulmonary shunt palliation. PATIENTS AND MAIN OUTCOME MEASURES Patients older than 18 years undergoing Fontan operation between 1 January 1982 and 31 December 1998 were identified. Mortality and late outcome were derived from hospital records. These patients were compared with a cohort of 50 adults with single ventricle who had not undergone a Fontan operation. RESULTS 61 adults, median age 36 years (range 18–47 years), with a median follow up of 10 years (range 0–21 years) were identified. Actuarial survival was 80% at one year, 76% at five years, 72% at 10 years, and 67% at 15 years. Compared with before the Fontan operation, more patients were in New York Heart Association (NYHA) functional class I or II at the latest follow up (80% v 58%, p < 0.001). Systolic ventricular function deteriorated during follow up such that 34% had moderate to severe ventricular dysfunction at the latest follow up compared with 5% before Fontan (p < 0.001). Arrhythmia increased with time (10% before Fontan v 57% after 10 years, p < 0.001). Fontan patients had improved NYHA functional class, ventricular function, atrioventricular regurgitation, and fewer arrhythmias than the non-Fontan group at the latest follow up. CONCLUSION The Fontan operation in adults has acceptable early and late mortality. Functional class, systolic ventricular function, atrioventricular regurgitation, and arrhythmia deteriorate late after surgery but to a lesser degree than in non-Fontan patients with a single ventricle.

Percutaneous catheter closure of the persistently patent ductus arteriosus in the adult

The USCI patent ductus occluder has been shown to be an effective nonsurgical technique for closure of the persistently patent ductus in a primarily pediatric population. Its clinical impact in the adult has been reported only within small subgroups of larger pediatric studies or for a small population. This study was conducted to determine the feasibility, success rate, and complications of device closure for the persistently patent ductus arteriosus (PDA) in the adult. The population consisted of 55 patients (4 men and 51 women; mean age 38.8 +/- 15.0 years) with follow-up of 2.2 +/- 2.1 years. All patients underwent echocardiography obtained as part of their follow-up assessment. The device was successfully placed in 54 patients, with 75% clinical and echocardiographic closure at the first follow-up assessment 2.4 +/- 2.6 months). One patient with initial clinical and echocardiographic evidence of closure was subsequently found to have an open ductus. Spontaneous closure (2 patients) or second implant (6 patients) resulted in 86% closure at the most recent assessment. Thus, the percutaneous PDA double-umbrella occluder device is a feasible and effective technique for closing persistent PDA in the adult and will result in occlusion of the shunt in most patients without the need for thoracotomy.

Pregnancy in women with congenital heart defects: what are the risks?

Increasing numbers of people with congenital heart defects (CHD) are surviving into adulthood as a result of advances in paediatric cardiology and cardiac surgery. As this patient group enters adulthood, reproductive issues and recurrence risks become a new and crucial focus for patients, partners, and caregivers. The pregnancy related changes in intravascular volume, cardiac output, and systemic vascular resistance may result in maternal or fetal deterioration in women with CHD. Pregnancy in women with CHD, not complicated by Eisenmenger syndrome, is associated with low mortality.1-3 However, they continue to be at risk for other cardiac complications such as arrhythmia, heart failure, or stroke. Poor maternal functional class, cyanosis, and the presence of significant aortic stenosis have been repeatedly mentioned as potential risk factors for maternal cardiac deterioration.1-5Maternal cyanosis is also a risk factor for fetal and neonatal complications.1-3 5 One recent study reported a 12% likelihood of a livebirth when the arterial oxygen saturation at rest was < 85%; the livebirth rate improved to 63% when the oxygen saturation was ⩾ 85%.5 In a recent study of 252 pregnancies in women with heart disease, the following independent predictors of cardiac events were identified3:

901-11 Late Clinical and Echocardiographic Follow-up After Left Ventricular Endoaneurysmorrhaphy

Infarct expansion and aneurysm (LVA) formation has a poor prognosis. Traditional techniques of LVA resection may be associated with suboptimal results, and do not fully restore LV geometry. LV endoaneurysmorrhaphy(LVEA) is a newer operative technique which utilizes an endocardial patch to exclude the aneurysm and normalize LV geometry. Late clinical and echocardiographic features of these patients (pts) is unknown. We prospectively followed 51 consecutive pts who had undergone LVEA. Average duration of follow-up (F/U) was 4.6 years (range 2-10 years). All pts had clinical evaluation and review of medical records. Results There were 2 (4%) peri-operative deaths, 2 (4%) in-hospital deaths, and 13 (24%) late deaths. Clinical improvement was noted in all 34 survivors: NYHA Class Pre-op F/U CCS Pre-op F/U n (%) n (%) n (%) n (%) I 5 (15) 21 (62) I 12 (35) 29 (85) II 9 (26) 8 (24) II 3 (9) 5 (15) III 13 (38) 4 (12) III 5 (15) 0 IV 7 (21) 1 (3) IV 14 (41) 0 30 surviving pts had F/U 2D echocardiograms (2DE). Near normal LV geometry was restored in all pts, and no patch aneurysms were noted at late F/U. 24/30 2DEs were adequate for quantitative analysis. The average LVEF post-op was 40.2% using the modified biplane analysis. Conclusions LV endoaneurysmorrhaphy was associated with a 72% overall survival after average 4.6 year F/U. All survivors had improvement in clinical status and normalization of LV geometry.