Enno T. van der Velde

Mortality in adult congenital heart disease

AIMS Mortality in adults with congenital heart disease is known to be increased, yet its extent and the major mortality risks are unclear. METHODS AND RESULTS The Dutch CONCOR national registry for adult congenital heart disease was linked to the national mortality registry. Coxs regression was used to assess mortality predictors. Of 6933 patients, 197 (2.8%) died during a follow-up of 24 865 patient-years. Compared with the general national population, there was excess mortality, particularly in the young. Median age at death was 48.8 years. Of all deaths, 77% had a cardiovascular origin; 45% were due to chronic heart failure (26%, age 51.0 years) or sudden death (19%, age 39.1 years). Age predicted mortality, as did gender, severity of defect, number of interventions, and number of complications [hazard ratio (HR) range 1.1-5.9, P < 0.05]. Several complications predicted all-cause mortality beyond the effects of age, gender, and congenital heart disease severity, i.e. endocarditis, supraventricular arrhythmias, ventricular arrhythmias, conduction disturbances, myocardial infarction, and pulmonary hypertension (HR range 1.4-3.1, P < 0.05). These risks were similar in patients above and below 40 years of age. Almost all complications predicted death due to heart failure (HR range 2.0-5.1, P < 0.05); conduction disturbances and pulmonary hypertension predicted sudden death (HR range 2.0-4.7, P < 0.05). CONCLUSION Mortality is increased in adults with congenital heart disease, particularly in the young. The vast majority die from cardiovascular causes. Mortality risk, particularly by heart failure, is increased by virtually all complications. Complications are equally hazardous in younger as in older patients.

The emerging burden of hospital admissions of adults with congenital heart disease

Objective To assess the extent and the characteristics of hospital admissions in registered adult patients with congenital heart disease. Design Observational cohort study. Setting The Netherlands. Patients 5798 adult patients with congenital heart disease from the Dutch CONCOR national registry linked to the Dutch National Medical Registration (Prismant). Main outcome measures All hospital admissions from the years 2001 up until 2006. Results During 28 990 patient-years, 2908 patients (50%) were admitted to hospital. Median age at admission was 39 years (range 18–86 years); 46% were male. Admission rate in CONCOR patients was high among all ages (range 11–68%) and exceeded that of the general Dutch population two to three times; this difference was most pronounced in the older age groups. Altogether there were 8916 admissions, 5411 (61%) of which were for cardiovascular indications. Among cardiovascular admissions, referrals for arrhythmias were most common (31%). Of 4926 interventions, 2459 (50%) were cardiovascular, most often reparative interventions or cardioversion (53%). Most non-cardiovascular admissions were obstetric. Among defects, univentricular heart and tricuspid atresia had the highest incidence and duration of admission. Conclusions Healthcare utilisation in registered and medically supervised adult patients with congenital heart disease is high and increases with age. Admission rates are at least two times higher than in the general population, and most marked in the older age groups. With the ageing of this population, a major increase in healthcare utilisation is imminent in the near future. Timely preparation of healthcare resources is crucial to sustain optimal care.

Risk of failure of transvenous implantable cardioverter-defibrillator leads.

Background—Despite the positive effect on mortality in selected patients, implantable cardioverter-defibrillator therapy is also associated with potential malfunction of the implanted system. The present study provides the long-term lead failure rate in a large single-center cohort. Methods and Results—Since 1992, a total of 2068 implantable cardioverter-defibrillator patients with 2161 defibrillation leads were prospectively collected. Data of the implant procedure and all follow-up visits were recorded. All cases of lead removal or capping or placing of an additional pace or sense lead were noted and analyzed. Lead models were grouped by manufacturer and approximate lead diameter in French. During a mean follow-up of 36 months, 82 (3.8%) cases of lead failure were identified. Cumulative incidence of lead failure at 1 year was 0.6%; at 5 years, 6.5%; and at 10 years, 16.4%. The highest risk of lead failure was found in small-diameter leads. Adjusted hazard ratio was 6.4 (95% CI, 3.2 to 12.8) for Medtronic 7F leads, when compared with all other leads. Conclusions—In this large single-center experience, the overall incidence of lead failure was 1.3 (95% CI, 1.0 to 1.6) per 100 lead-years. Comparison of different groups of leads shows major differences in event rates. Specific manufacturer’s small-diameter defibrillation leads may have a higher risk of early lead failure.

Gender and Outcome in Adult Congenital Heart Disease

Background— Gender differences in prognosis have frequently been reported in cardiovascular disease but less so in congenital heart disease. We investigated whether gender is associated with outcome in adult patients with congenital heart disease. Methods and Results— From the CONgenital CORvitia (CONCOR) national registry for adults with congenital heart disease, 7414 patients were identified. All outcomes before entry into the registry and during subsequent follow-up were recorded, and differences between men and women were analyzed with the underlying congenital heart defect taken into account. Median age at the end of follow-up was 35 years (range, 17 to 91 years); 49.8% were female. No gender difference in mortality was found. Women had a 33% higher risk of pulmonary hypertension (odds ratio [OR]=1.33; 95% CI, 1.07 to 1.65; P=0.01), a 33% lower risk of aortic outcomes (OR=0.67; 95% CI, 0.50 to 0.90; P=0.007), a 47% lower risk of endocarditis (OR=0.53; 95% CI, 0.40 to 0.70; P<0.001), and a 55% lower risk of an implantable cardioverter-defibrillator (OR=0.45; 95% CI, 0.26 to 0.80; P=0.006). Furthermore, the risk of arrhythmias appeared to be lower in women (OR=0.88; 95% CI, 0.77 to 1.02; P=0.08). Conclusions— The risk of several major cardiac outcomes in adult patients with congenital heart disease appears to vary by gender.

Association between diffuse myocardial fibrosis by cardiac magnetic resonance contrast-enhanced T(1) mapping and subclinical myocardial dysfunction in diabetic patients: a pilot study.

Background— Diabetic patients have increased interstitial myocardial fibrosis on histological examination. Magnetic resonance imaging (MRI) T1 mapping is a previously validated imaging technique that can quantify the burden of global and regional interstitial fibrosis. However, the association between MRI T1 mapping and subtle left ventricular (LV) dysfunction in diabetic patients is unknown. Methods and Results— Fifty diabetic patients with normal LV ejection fraction (EF) and no underlying coronary artery disease or regional macroscopic scar on MRI delayed enhancement were prospectively recruited. Diabetic patients were compared with 19 healthy controls who were frequency matched in age, sex and body mass index. There were no significant differences in mean LV end-diastolic volume index, end-systolic volume index and LVEF between diabetic patients and healthy controls. Diabetic patients had significantly shorter global contrast-enhanced myocardial T1 time (425±72 ms vs. 504±34 ms, P<0.001). There was no correlation between global contrast-enhanced myocardial T1 time and LVEF (r=0.14, P=0.32) in the diabetic patients. However, there was good correlation between global contrast-enhanced myocardial T1 time and global longitudinal strain (r=−0.73, P<0.001). Global contrast-enhanced myocardial T1 time was the strongest independent determinant of global longitudinal strain on multivariate analysis (standardized &bgr;=−0.626, P<0.001). Similarly, there was good correlation between global contrast-enhanced myocardial T1 time and septal E′ (r=0.54, P<0.001). Global contrast-enhanced myocardial T1 time was also the strongest independent determinant of septal E′ (standardized &bgr;=0.432, P<0.001). Conclusions— A shorter global contrast-enhanced myocardial T1 time was associated with more impaired longitudinal myocardial systolic and diastolic function in diabetic patients.

Voltage and activation mapping: how the recording technique affects the outcome of catheter ablation procedures in patients with congenital heart disease.

Background—Endocardial mapping is mandatory before radiofrequency catheter ablation (RFCA). Mapping can be performed with either unipolar or bipolar recordings. Impact of the recording technique used was studied in patients with and without structural heart disease using the 3D electroanatomic CARTO mapping system. Methods and Results—Patients (n=44; 16 males; age 43±16 years) referred for RFCA of atrial flutter (AFL, n=18), focal atrial tachycardia (FAT, n=4), AV nodal reentrant tachycardia (AVNRT, n=5), or scar-related atrial reentrant tachycardia (IART, n=17) were studied. Voltage and activation maps were constructed. Unipolar and bipolar voltage distribution in the different groups was studied to establish a cutoff voltage value to facilitate delineation of scar tissue. Electrograms were recorded during tachycardia (FAT: n=246, cycle length [CL]=449±35 ms; AVNRT: n=182, CL=359±47 ms; AFL: n=1164, CL=255±56 ms; IART: n=2431, CL=280±74 ms). Unipolar voltages were greater than bipolar voltages (P <0.001). Unipolar voltages ≤1.0 mV were equally distributed in both AFL and IART patients. Bipolar voltages ≤0.1 mV were only found in patients with IART, and subsequently 0.1 mV was used as the cutoff value to delineate scar tissue. No unipolar cutoff value could be established. Timing of unipolar and bipolar local activation was correlated in all patient groups. Conclusions—The recording technique used has considerable impact on reconstruction of reentrant pathways and on the outcome of RFCA. In general, unipolar and bipolar recordings provide complementary information; however, only bipolar recordings allow voltage-based scar tissue delineation in patients with congenital heart disease.

Social Burden and Lifestyle in Adults With Congenital Heart Disease

We aimed to evaluate how the presence and severity of congenital heart disease (CHD) influence social life and lifestyle in adult patients. A random sample (n = 1,496) from the CONgenital CORvitia (n = 11,047), the Dutch national registry of adult patients with CHD, completed a questionnaire on educational attainment, employment and marital statuses, and lifestyle (response 76%). The Utrecht Health Project provided a large reference group (n = 6,810) of unaffected subjects. Logistic regression models were used for subgroup analyses and to adjust for age, gender, and socioeconomic status where appropriate. Of all patients 51.5% were men (median age 39 years, interquartile range 29 to 51) with mild (46%), moderate (44%), and severe (10%) CHD. Young (<40-year-old) patients with CHD were more likely to have achieved a lower education (adjusted odds ratios [ORs] 1.6 for men and 1.9 for women, p <0.05 for the 2 comparisons), significantly more often unemployed (adjusted ORs 5.9 and 2.0 for men and women, respectively), and less likely to be in a relationship compared to the reference group (adjusted ORs 8.5 for men and 4.5 for women). These poorer outcomes were seen in all severity groups. Overall, the CHD population smoked less (adjusted OR 0.5, p <0.05), had more sports participation (adjusted OR 1.2, p <0.05), and had less obesity (adjusted OR 0.7, p <0.05) than the reference group. In conclusion, there was a substantial social disadvantage in adult patients with CHD, which was seen in all severity groups and primarily in young men. In contrast, adults with CHD had healthier lifestyles compared to the reference group.

Circumstances of death in adult congenital heart disease

BACKGROUND Circumstances of death have been described for various cardiovascular diseases, but this study is the first for adults with congenital heart disease (CHD). METHODS Review of medical records and additional information from treating cardiologists and general practitioners, for circumstances of all deaths in a national registry of over 8000 adults with CHD. RESULTS Of 8595 patients, 231 (2.7%) patients died over 26,500 patient years. Main causes of death were progressive heart failure (26%) and sudden cardiac death (22%). Mortality was highest in the northern, most rural region of the country (p ≤ 0.05). Overall, death occurred out-of-hospital in approximately 35%, but more frequently in rural than in urban areas (55% versus 32%, p ≤ 0.05). Mortality was almost equally distributed throughout the seasons, although fall showed a slightly higher mortality rate. Cardiovascular death occurred suddenly in nearly 40%. Sudden cardiovascular death occurred in 8% during exercise, and most often out-of-hospital (62%). Of non-sudden cardiovascular deaths 18% had occurred out-of-hospital. CONCLUSION In adult patients with congenital heart disease, mortality shows substantial regional and subtle seasonal variation. Death usually occurs at rest; approximately 1 of 10 sudden cardiovascular deaths occur during exercise.

Endocardial Activation Mapping of Ventricular Tachycardia in Patients First Application of a 32-Site Bipolar Mapping Electrode Catheter

BACKGROUND Localization of early activated endocardial areas during ventricular tachycardia (VT) is mandatory for performance of surgical or radiofrequency catheter interventions. The use of a multielectrode catheter may shorten the procedure time and increase the accuracy of the procedure compared with single-electrode mapping techniques. This study was performed to evaluate the safety and efficacy of a 32-bipolar-electrode mapping catheter in patients. METHODS AND RESULTS The basket-shaped mapping catheter (BMC), integrated with a computerized mapping system, allowed on-line reconstruction of endocardial activation maps. Twenty patients with VT were studied before surgery (n=4) or radiofrequency catheter ablation (n=16). End-diastolic left ventricular (LV) volume was 280+/-120 mL, with an LV ejection fraction of 33+/-14%. The volume encompassed by the BMC was 164+/-27 mL (130 to 200 mL); the deployment time was 46+/-11 minutes. Endocardial activation time during sinus rhythm was 105+/-34 ms; 14+/-5 electrodes could be used to stimulate the heart. Cycle length of VT was 325+/-83 ms. Earliest endocardial activation was recorded 58+/-42 ms before the onset of the surface ECG. Complications were pericardial effusion (n=2) and transient cerebral disorientation (n=1). CONCLUSIONS Percutaneous multielectrode endocardial mapping in patients with VT is feasible and relatively safe. The use of this technique shortens the time patients have to endure VT.

Turning 18 with congenital heart disease: prediction of infective endocarditis based on a large population

AIMS The risk of infective endocarditis (IE) in adults with congenital heart disease is known to be increased, yet empirical risk estimates are lacking. We sought to predict the occurrence of IE in patients with congenital heart disease at the transition from childhood into adulthood. METHODS AND RESULTS We identified patients from the CONCOR national registry for adults with congenital heart disease. Potential predictors included patient characteristics, and complications and interventions in childhood. The outcome measure was the occurrence of IE up to the age of 40 and 60. A prediction model was derived using the Cox proportional hazards model and bootstrapping techniques. The model was transformed into a clinically applicable risk score. Of 10 210 patients, 233 (2.3%) developed adult-onset IE during 220 688 patient-years. Predictors of IE were gender, main congenital heart defect, multiple heart defects, and three types of complications in childhood. Up to the age of 40, patients with a low predicted risk (<3%) had an observed incidence of less than 1%; those with a high predicted risk (≥3%) had an observed incidence of 6%. The model also yielded accurate predictions up to the age of 60. CONCLUSION Among young adult patients with congenital heart disease, the use of six simple clinical parameters can accurately predict patients at relatively low or high risk of IE. After confirmation in other cohorts, application of the prediction model may lead to individually tailored medical surveillance and educational counselling, thus averting IE or enabling timely detection in adult patients with congenital heart disease.