Transcatheter pulmonary valve implantation: valve technology and procedural outcome.

PURPOSE OF REVIEW: Procedural technique and short-term outcomes of transcatheter pulmonary valve implantation (TPVI) have been widely described. The purpose of this article is to provide an update on current valve technology, and to focus on recent data surrounding TPVI in the dilated right ventricular outflow tract (RVOT), hybrid interventions, significant outcomes, and procedural costs. RECENT FINDINGS: Transcatheter valve technology has expanded with current trials evaluating self-expandable valves that can be implanted in dilated RVOTs. Until those valves are widely available, hybrid techniques have been shown to offer a potential alternative in these patients, as well as in patients of small size. Although medium-term results of TPVI have shown 5-year freedom from reintervention or replacement of 76%, new data have underlined some concerns relating to bacterial endocarditis after the procedure. Procedural costs remain a concern, but vary greatly between institutions and healthcare systems. SUMMARY: TPVI has emerged as one of the most innovative procedures in the treatment of patients with dysfunctional RVOT and pulmonary valves. Further device development is likely to expand the procedure to patients of smaller size and with complex, dilated RVOTs.

Balloon valvuloplasty for congenital aortic stenosis: Multi-center safety and efficacy outcome assessment.

OBJECTIVE: To describe contemporary outcomes of balloon aortic valvuloplasty (BAVP) performed in 22 US centers. BACKGROUND: BAVP constitutes first-line therapy for congenital aortic stenosis (cAS) in many centers. METHODS: We used prospectively-collected data from two active, multi-institutional, pediatric cardiac catheterization registries. Acute procedural success was defined, for purposes of this review, as a residual peak systolic gradient≤35 mm Hg and no more than mild aortic regurgitation (AR) for patients with isolated cAS. For patients with mixed aortic valve disease, a residual peak systolic gradient≤35 mm Hg without worsening of AR was considered successful outcome. RESULTS: In 373 patients with a median age of 8 months (1 day to 40 years of age) peak systolic gradient had a median of 59 [50, 71] mm Hg pre-BAVP and 22 [15, 30] mm Hg post-BAVP (P<0.001). Procedural success was achieved in 160 patients (71%). The factors independently associated with procedural success were: first time intervention (OR=2.0 (1.0, 4.0) P=0.04), not-prostaglandin dependent, (OR=3.5 (1.5, 8.1); P=0.003), and isolated cAS (absence of AR) (OR=2.1 (1.1-3.9); P=0.03). Twenty percent of patients experienced adverse events, half of which were of high severity. There was no procedural mortality. Neonatal status was the only factor associated with increased risk of high severity adverse events (OR 3.7; 95% CI 1.5-9.0). CONCLUSION: In the current era, BAVP results in procedural success (gradient reduction with minimal increase in AR) in 71% of patients treated at US centers where BAVP is considered first-line therapy relative to surgery.

Comparing echocardiographic assessment of systolic function with catheterization data in patients with single right ventricles.

PURPOSE: Echocardiographic evaluation of systolic function in patients with single right ventricles (SRV) is important but remains challenging. Minimal data exist correlating echocardiographic indices with catheterization data in this population. The goal of this study was to evaluate which echocardiographic measurement correlated best with dP/dt (max) obtained by cardiac catheterization in SRV patients. METHODS: Patients with SRV physiology who underwent simultaneous echocardiography and cardiac catheterization were evaluated. Echocardiographic data included fractional area change % (FAC), displacement, TDI s'wave, myocardial performance index (MPI), global systolic strain, and global SR s wave. Maximum positive rate of ventricular pressure change measured as dP/dt (max) was obtained from the cardiac catheterization report. Correlations of echocardiographic and catheterization variables were examined using the Pearson correlation. RESULTS: Twenty-seven SRV patients were studied. Median age at the time of the catheterization was 11.4 months (range 0 - 132 months). dP/dt (max) values ranged from 337-1860 mmHg/s with a median of 994 mmHg/s. Mean FAC was 27.15 +/- 7.13%, displacement was 7.35 +/- 2.88 mm, TDI s' was 4.98 +/- 1.93 cm/sec, MPI was 0.41 +/- 0.17, global strain was-14.85 +/- 4.32%, and global SR s wave was -1.03 +/- 0.34 sec(-1). There were no significant correlations between dP/dt (max) and any of the echocardiographic measurements of systolic function in SRV patients. CONCLUSION: In patients with SRV physiology, catheterization-derived dP/dt (max) did not correlate with echocardiographic measurements of systolic function. Larger studies are needed to determine which non-invasive parameter best describes systolic function in patients with SRV.

Incidence and management of life-threatening adverse events during cardiac catheterization for congenital heart disease.

Continued advancements in congenital cardiac catheterization and interventions have resulted in increased patient and procedural complexity. Anticipation of life-threatening events and required rescue measures is a critical component to preprocedural preparation. We sought to determine the incidence and nature of life-threatening adverse events in congenital and pediatric cardiac catheterization, risk factors, and resources necessary to anticipate and manage events. Data from 8905 cases performed at the 8 participating institutions of the Congenital Cardiac Catheterization Project on Outcomes were captured between 2007 and 2010 [median 1,095/site (range 133-3,802)]. The incidence of all life-threatening events was 2.1 % [95 % confidence interval (CI) 1.8-2.4 %], whereas mortality was 0.28 % (95 % CI 0.18-0.41 %). Fifty-seven life-threatening events required cardiopulmonary resuscitation, whereas 9 % required extracorporeal membrane oxygenation. Use of a risk adjustment model showed that age <1 year [odd ratio (OR) 1.9, 95 % CI 1.4-2.7, p < 0.001], hemodynamic vulnerability (OR 1.6, 95 % CI 1.1-2.3, p < 0.01), and procedure risk (category 3: OR 2.3, 95 % CI 1.3-4.1; category 4: OR 4.2, 95 % CI 2.4-7.4) were predictors of life-threatening events. Using this model, standardized life-threatening event ratios were calculated, thus showing that one institution had a life-threatening event rate greater than expected. Congenital cardiac catheterization and intervention can be performed safely with a low rate of life-threatening events and mortality; preprocedural evaluation of risk may optimize preparation of emergency rescue and bailout procedures. Risk predictors (age < 1, hemodynamic vulnerability, and procedure risk category) can enhance preprocedural patient risk stratification and planning.

Prioritization of congenital cardiac surgical patients using fuzzy reasoning--a solution to the problem of the waiting list?

Surgical waiting lists are of high importance in countries, where the national health system is unable to deliver surgical services at a rate that would allow patients to avoid unnecessary periods of waiting. Prioritization of these lists, however, is frequently arbitrary and inconsistent. The objective of our research was to analyze the medical decision-making process when prioritizing patients with congenital cardiac malformations for cardiac surgical procedures, identifying an appropriate representation of knowledge, and transferring this knowledge onto the design and implementation of an expert system ("PrioHeart"). The medical decision-making process was stratified into three stages. The first was to analyze the details of the procedure and patient to define important impact factors on clinical priority, such as the risk of adverse events. The second step was to evaluate these impact factors to define an appropriate "timing category" within which a procedure should be performed. The third, and final, step was to re-evaluate the characteristics of individual patients to differentiate between those in the same timing category. We implemented this decision-making process using a rule-based production system with support for fuzzy sets, using the FuzzyCLIPS inference engine and expert system shell as a suitable development environment for the knowledge base. The "PrioHeart" expert system was developed to give paediatric cardiologists a tool to allow and facilitate the prioritization of patients on the cardiosurgical waiting list. Evaluation of "PrioHeart" on limited sets of patients documented appropriate results of prioritization, with a significant correlation between the prioritization made using "PrioHeart" and those results obtained by the individual consultant specialist. We conclude that our study has demonstrated the feasibility of using an expert system approach with a fuzzy, rule-based production system to implement the prioritization of cardiac surgical patients. The approach may potentially be transferable to other medical subspecialities.