Pamela D. Miner

Structural Abnormalities of Great Arterial Walls in Congenital Heart Disease: Light and Electron Microscopic Analyses

BackgroundGreat arteries in congenital heart disease (CHD) may dilate, become aneurysmal, or rupture. Little is known about medial abnormalities in these arterial walls. Accordingly, we studied 18 types of CHD in patients from neonates to older adults. Methods and ResultsIntraoperative biopsies from ascending aorta, paracoarctation aorta, truncus arteriosus, and pulmonary trunk in 86 patients were supplemented by 16 necropsy specimens. The 102 patients were 3 weeks to 81 years old (average, 32±6 years). Biopsies were examined by light (LM) and electron (EM) microscopy; necropsy specimens by LM. Positive aortic controls were from 15 Marfan patients. Negative aortic controls were from 11 coronary artery disease patients and 1 transplant donor. Nine biopsies from acquired trileaflet aortic stenosis were compared with biopsies from bicuspid aortic stenosis. Negative pulmonary trunk controls were from 7 coronary artery disease patients. A grading system consisted of negative controls and grades 1, 2, and 3 (positive controls) based on LM and EM examination of medial constituents. ConclusionsMedial abnormalities in ascending aorta, paracoarctation aorta, truncus arteriosus, and pulmonary trunk were prevalent in patients with a variety of forms of CHD encompassing a wide age range. Aortic abnormalities may predispose to dilatation, aneurysm, and rupture. Pulmonary trunk abnormalities may predispose to dilatation and aneurysm; hypertensive aneurysms may rupture. Pivotal questions are whether these abnormalities are inherent or acquired, whether CHD plays a causal or facilitating role, and whether genetic determinants are operative.

Risk of stroke in adults with cyanotic congenital heart disease.

BackgroundAdults with cyanotic congenital heart disease and elevated hematocrit levels are often phlebotomized because of an assumed risk of cerebral arterial thrombotic stroke. Whether a relation exists between hematocrit level, symptomatic erythrocytosis (hyperviscosity), and stroke remains to be established in this patient population Methods and ResultsAccordingly, 112 cyanotic patients 19-74 years old (mean, 36±11.7 years) in the UCLA Adult Congenital Heart Disease Center Registry were selected for study by virtue of continuous observation for 1-12 years (total, 748 patient-years). Patients with independent risk factors for embolic or vasospastic stroke were excluded. The study patients were then divided into two groups: 1) compensated erythrocytosis (stable hematocrit levels of 46.0-72.7% [mean, 57.5±7.2%], iron replete, absent or mild hyperviscosity symptoms), and 2) decompensated erythrocytosis (unstable rising hematocrit levels of 61.5-75.0% [mean, 69.5±10.6%], iron deficiency, marked-to-severe hyperviscosity symptoms). No patient with either compensated or decompensated erythrocytosis, irrespective of hematocrit level, iron stores, or the presence, degree, or recurrence of cerebral hyperviscosity symptoms, progressed to clinical evidence of a completed stroke (cerebral arterial thrombosis with brain infarction). ConclusionBecause a risk of stroke caused by cerebral arterial thrombosis was not demonstrated, because the circulatory effects of phlebotomy are transient, and because of the untoward sequelae of phlebotomy-induced iron deficiency, we recommend phlebotomy for the temporary relief of significant, intrusive hyperviscosity symptoms but not for the hematocrit level per se. According to our data, phlebotomy is not warranted to reduce an assumed risk of stroke because that risk did not materialize. (Circulation 1993;87:1954-1959)

Eisenmenger syndrome in adults: Ventricular septal defect, truncus arteriosus, univentricular heart

OBJECTIVES Morbidity and mortality patterns were characterized in adults with the Eisenmenger syndrome when two ventricles with a ventricular septal defect (VSD) joined two great arteries or one great artery, or when one ventricle joined two great arteries. BACKGROUND Although afterload in these disorders differs, clinical differences have not been defined. METHODS Seventy-seven patients were studied. Group A comprised 47 patients with VSD, aged 23 to 69 years (mean 39.5+/-10.2), follow-up 5 to 18 years (mean 7.2+/-4.9); group B, 14 patients with truncus arteriosus, aged 27 to 50 years (mean 33.7+/-7.3), follow-up 6 to 18 years (mean 7.7+/-5.1), and group C, 16 patients with univentricular heart, aged 18 to 44 years (mean 30.6+/-8.4), follow-up 5 to 15 years (mean 4.4+/-4.2). Echocardiography established the diagnoses and anatomic and hemodynamic features. Data were compiled on tachyarrhythmias, pregnancy, infective endocarditis, noncardiac surgery and the multisystem disorders of cyanotic adults. RESULTS Thirty-five percent of the patients died. Sixty-three percent of deaths were sudden, and resulted from intrapulmonary hemorrhage, rupture of either the pulmonary trunk, ascending aorta or a bronchial artery, or vasospastic cerebral infarction, or the cause was unestablished. There were no documented tachyarrhythmic sudden deaths. CONCLUSIONS Medical management of coexisting cardiac disease, multisystem systemic disorders, noncardiac surgery and pregnancy has reduced morbidity. Increased longevity exposed patients to proximal pulmonary arterial aneurysms, thromboses and calcification; to truncal valve stenosis and regurgitation; to semilunar and atrioventricular valve regurgitation, and to major risks of nontachyarrhythmic sudden death.

Task Force 3: workforce description and educational requirements for the care of adults with congenital heart disease

The expansion of the population of adults with congenital heart disease (CHD) and the increasing survival of patients with complex disease into adulthood have heightened the need for specifically trained individuals who can provide comprehensive outpatient and in-patient care and consultative

Arrhythmia Recurrence in Adult Patients with Single Ventricle Physiology Following Surgical Fontan Conversion: Arrhythmia Recurrence Following Fontan Conversion

OBJECTIVES To evaluate the incidence of atrial tachy-arrhythmia (AT) recurrence following conversion from right atrial-pulmonary artery (RA-PA) Fontan to total cavopulmonary connection (TCPC) in adults. BACKGROUND AT is a recognized sequel of Fontan palliation, especially in RA-PA Fontans, and is associated with significant morbidity. While catheter ablation achieves fairly reliable short-term success with low morbidity, conversion to TCPC with arrhythmia surgery is a highly effective treatment option for the classical Fontan patients with incessant AT. METHODS Single center retrospective review. RESULTS Twenty-seven adults underwent Fontan conversion from RA-PA to TCPC, mostly for AT indications (n = 24). Nine (33%) underwent conversion to a lateral tunnel (LT) and 18 (67%) to an extracardiac (EC) Fontan. Two patients died <30 days post-operatively. Both had liver failure and had been turned down for cardiac/liver transplantation. In-hospital complications occurred in 15/27 patients (55%), including recurrence of AT requiring cardioversion in six patients (22%) and persistent pleural effusions in 4 (15%). Mean follow-up was 4.2 years (range 3 months-14 years). Functional capacity improved from mean New York Heart Association (NYHA) class 1.8 pre-conversion to 1.2 post-conversion (P= 0.008). Twenty-one patients had concomitant arrhythmia surgery (MAZE in 12 patients with IART and Cox-MAZE in nine patients with A-Fib +/- IART). Of these, 3/21 (14%) had AT recurrence >3 months following conversion. CONCLUSIONS Conversion from RA-PA Fontan to TCPC, with arrhythmia surgery, decreases AT recurrence and improves functional capacity. The risk of peri-operative mortality is highest in patients with cirrhosis. AT recurred in 14% of patients.

Usefulness of Serum Brain Natriuretic Peptide to Predict Adverse Events in Patients With the Eisenmenger Syndrome

The aim of this study was to evaluate the prognostic value of brain natriuretic peptide (BNP) in outpatients with the Eisenmenger syndrome (ES). BNP is often elevated in patients with cyanotic congenital heart disease. The clinical utility of BNP in patients with cyanotic congenital heart disease and the ES has not been clearly delineated. Records of adults with ES who had undergone serum BNP measurement were reviewed. The primary end point was death or heart failure admission. Fifty-three patients were included, with 15 patients (28%) meeting the primary end point (death in 7, heart failure hospitalization in 8). Mean and median baseline BNP in patients meeting the primary end point were 322 ± 346 and 179 pg/ml, compared to 100 ± 157 and 41 pg/ml in those not meeting the primary end point (p = 0.0029). A Cox proportional-hazards model using baseline BNP between the 2 groups yielded a hazard ratio of 1.84 (95% confidence interval [CI] 1.19 to 2.85, p = 0.006). The relative risk for baseline BNP level >140 pg/ml was 4.62 (95% CI 1.80 to 11.3, p = 0.008). Patients who met the primary end point increased their BNP levels by 42.5 pg/ml per year (95% CI 12.09 to 72.95, p = 0.006) compared to 7.2 pg/ml per year (95% CI 2.01 to 12.47, p = 0.007) in patients who did not meet the primary end point. In conclusion, elevated BNP levels are predictive of death or heart failure admission in patients with the ES. A serum BNP level >140 pg/ml is a useful tool in identifying high-risk patients.

EFFICACY OF ENDOTHELIN BLOCKADE IN ADULTS WITH FONTAN PHYSIOLOGY

OBJECTIVE Phosphodiesterase-5 inhibitors have shown to improve cardiac output and functional capacity in Fontan patients. We sought to test the efficacy and safety of endothelin blockade with bosentan in adult patients with Fontan physiology. DESIGN Ten patients were enrolled and seven patients completed this single-center open-label clinical trial. Patients were treated with bosentan for 4 months. Cardiac magnetic resonance imaging (MRI), 6-minute walking distance (6MWD), brain natriuretic peptide, and New York Heart Association functional class were compared before and after treatment using paired t-test. RESULTS The 6MWD improved by 73 m, from a mean of 435 m (standard deviation [SD] = 92, standard error [SE] = 35) to 508 m (SD = 93, SE = 35) (P = .03). MRI resting aortic flow increased from 3.3 L/minute (SD = 1.27, SE = 0.73) to 4.4 L/minute (SD = 0.9, SE = 0.54) (P = .03). New York Heart Association class was unchanged in three patients, improved in three patients and worsened in one patient. Brain natriuretic peptide, aspartate aminotransferase, and alanine aminotransferase did not change significantly. Of the three patients with elevated baseline bilirubin, two normalized at the completion of the study, while the other was unchanged. Mean duration of therapy was 4.1 ± 0.51 months. Three adverse advents occurred. One patient complained of fatigue and chest pain after 87 days and withdrew from the study. After extensive workup, it was determined that her symptoms were not related to treatment. The second patient suffered palpitations and fatigue after 75 days; no concerning arrhythmias were identified and symptoms improved with increased antiarrhythmic dose. The third patient developed fatigue on therapy and decided to stop therapy; fatigue improved following drug discontinuation. There were no deaths or hospitalizations. CONCLUSIONS In this cohort of adult patients with Fontan physiology, endothelin blockade with bosentan resulted in improved 6MWD and MRI-derived resting cardiac output, suggesting a positive effect on pulmonary vascular resistance and pulmonary blood flow. Bosentan was well tolerated and hepatic function was not adversely affected.

Efficacy and Safety of Bosentan in Adults with Simple and Complex Eisenmenger's Syndrome

BACKGROUND   Eisenmengers syndrome (ES) is associated with decreased longevity and reduced functional capacity. Targeted pharmacologic therapies improve functional capacity and survival in these patients. We sought to compare the response of patients with simple vs. complex ES following initiation of bosentan. METHODS   ES patients with a history of bosentan use were identified by chart review. Simple ES was defined as ES associated with atrial septal defect, ventricular septal defect, or patent ductus arteriosus. Complex ES consisted of patients with truncus arteriosus and single ventricle congenital heart disease. Six-minute walking distance (6MWD), maximal oxygen consumption (VO(2) max), brain natriuretic peptide (BNP), and resting oxygen saturation were compared between simple and complex ES patients before and after bosentan treatment. RESULTS   Twenty-four patients were included (11 simple, 13 complex). Resting oxygen saturation, 6MWD, VO(2) max, and BNP were not significantly different between the two groups prior to bosentan initiation. Ten patients received bosentan monotherapy, and bosentan was used in combination with sildenafil in 13 (five simple, eight complex). One patient received bosentan with iloprost. Mean duration of therapy was 38 ± 14 months in the simple group and 40 ± 8.1 months in the complex group (P= NS). Posttreatment, 6MWD increased from 274 ± 135 m to 326 ± 106 m in simple ES patients (P= .32). 6MWD in patients with complex ES increased from 332 ± 51 m to 364 ± 109 (P= .028). VO(2) max improved from 13.4 ± 3.8 to 17 ± 6 (P= .54) in the simple group, while VO(2) max in the complex group improved from 12.7 ± 2.3 to 15.5 ± 2.2 (P= .17). There was minimal change in BNP or resting oxygen saturation between the groups. CONCLUSIONS   Treatment with bosentan is both safe and effective in patients with both simple and complex forms of ES.