Respiratory Training Late After Fontan Intervention: Impact on Cardiorespiratory Performance.

Fontan palliation allows patients with "single ventricle" circulation to reach adulthood with an acceptable quality of life, although exercise tolerance is significantly reduced. To assess whether controlled respiratory training (CRT) increases cardiorespiratory performance. 16 Adolescent Fontan patients (age 17. 5 ± 3.8 years) were enrolled. Patients were divided into CRT group (n = 10) and control group (C group, n = 6). Maximal cardiopulmonary test (CPT) was repeated at the end of CRT in the CRT group and after an average time of 3 months in the C group. In the CRT group a CPT endurance was also performed before and after CRT. In the CRT group there was a significant improvement in cardiovascular and respiratory response to exercise after CRT. Actually, after accounting for baseline values, the CRT group had decreased breathing respiratory reserve (- 15, 95% CI -22.3 to - 8.0, p = 0.001) and increased RR peak (+ 4.8, 95% CI 0.7-8.9, p = 0.03), VE peak (+ 13.7, 95% CI 5.6-21.7, p = 0.004), VO2 of predicted (+ 8.5, 95% CI 0.1-17.0, p = 0.05), VO2 peak (+ 4.3, 95% CI 0.3 to 8.2, p = 0.04), and VO2 workslope (+ 1.7, 95% CI 0.3-3.1, p = 0.02) as compared to the control group. Moreover, exercise endurance time increased from 8.45 to 17.7 min (p = 0.01). CRT improves cardiorespiratory performance in post-Fontan patients leading to a better aerobic capacity.

Effective Cardiac Index and Systemic-Pulmonary Collaterals Evaluated by Cardiac Magnetic Resonance Late After Fontan Palliation.

The regulation of cardiac output in the Fontan circuit is not completely understood. Systemic-pulmonary collaterals (SPCs) are frequent in patients with univentricular heart, and their clinical significance and management remain controversial. The aims of our study were to identify factors associated with SPCs' flow at late follow-up after Fontan and evaluate the relation between SPCs flow (QSPCs) and the effective cardiac index (CI). From our cardiac magnetic resonance database, we identified all Fontan patients with a complete set of flow measurements allowing calculation of QSPCs and effective CI. QSPCs was calculated as (left pulmonary veins flow + right pulmonary veins flow) - (right pulmonary artery flow + left pulmonary artery flow). Effective CI was calculated as (Aortic flow (QAo) - QSPCs)/BSA. Medical, surgical history, and clinical status were recorded. Sixty-four post-Fontan patients (36 male; mean age 19 ± 10 years) were included in the study. Median QSPCs was 0.7 L/min/m2 (interquartile [IQ] range 0.386-0.983) accounting for a median of 21% (IQ range 13-28) of aortic flow. The effective CI in our population was 2.4 ± 0.6 L/min/m2. QSPCs inversely correlate with left pulmonary artery area (r = -0.37, p = 0.004) and total antegrade pulmonary flow (r = -0.32, p = 0.01). QSPCs correlate with indexed aortic flow (r = 0.6, p <0.001) and inversely correlate with effective CI (r = -0.39, p = 0.002). Effective CI inversely correlates with age at study and age at the Fontan palliation (r = -0.35, p = 0.005, and r = -0.29, p = 0.02, respectively) and positively with ventricular ejection fraction (r = 0.3, p = 0.01). In conclusion, SPCs are common in Fontan patients, correlate inversely with effective CI, and are associated with a reduced antegrade pulmonary flow. In cardiac magnetic resonance evaluation of post-Fontan patients, effective CI should be taken into account rather than the total CI.

Left ventricular reverse remodeling after transcatheter aortic valve implantation: a cardiovascular magnetic resonance study.

BACKGROUND: In patients with severe aortic stenosis, left ventricular hypertrophy is associated with increased myocardial stiffness and dysfunction linked to cardiac morbidity and mortality. We aimed at systematically investigating the degree of left ventricular mass regression and changes in left ventricular function six months after transcatheter aortic valve implantation (TAVI) by cardiovascular magnetic resonance (CMR). METHODS: Left ventricular mass indexed to body surface area (LVMi), end diastolic volume indexed to body surface area (LVEDVi), left ventricular ejection fraction (LVEF) and stroke volume (SV) were investigated by CMR before and six months after TAVI in patients with severe aortic stenosis and contraindications for surgical aortic valve replacement. RESULTS: Twenty-sevent patients had paired CMR at baseline and at 6-month follow-up (N=27), with a mean age of 80.7±5.2 years. LVMi decreased from 84.5±25.2 g/m2 at baseline to 69.4±18.4 g/m2 at six months follow-up (P<0.001). LVEDVi (87.2±30.1 ml /m2vs 86.4±22.3 ml/m2; P=0.84), LVEF (61.5±14.5% vs 65.1±7.2%, P=0.08) and SV (89.2±22 ml vs 94.7±26.5 ml; P=0.25) did not change significantly. CONCLUSIONS: Based on CMR, significant left ventricular reverse remodeling occurs six months after TAVI.

Comparison of complications and outcomes to one year of transcatheter aortic valve implantation versus surgical aortic valve replacement in patients with severe aortic stenosis.

Comparisons of transcatheter aortic valve implantation (TAVI) to surgical aortic valve replacement (SAVR) in patients with severe aortic stenosis remain sparse or limited by a short follow-up. We sought to evaluate early and midterm outcomes of consecutive patients (n = 618) undergoing successful TAVI (n = 218) or isolated SAVR (n = 400) at 2 centers. The primary end point was incidence of Valvular Academic Research Consortium-defined major adverse cerebrovascular and cardiac events (MACCEs) up to 1 year. Control of potential confounders was attempted with extensive statistical adjustment by covariates and/or propensity score. In-hospital MACCEs occurred in 73 patients (11.8%) and was more frequent in patients treated with SAVR compared to those treated with TAVI (7.8% vs 14.0%, p = 0.022). After addressing potential confounders using 3 methods of statistical adjustment, SAVR was consistently associated with a higher risk of MACCEs than TAVI, with estimates of relative risk ranging from 2.2 to 2.6 at 30 days, 2.3 to 2.5 at 6 months, and 2.0 to 2.2 at 12 months. This difference was driven by an adjusted increased risk of life-threatening bleeding at 6 and 12 months and stroke at 12 months with SAVR. Conversely, no differences in adjusted risk of death, stroke and myocardial infarction were noted between TAVI and SAVR at each time point. In conclusion, in a large observational registry with admitted potential for selection bias and residual confounding, TAVI was not associated with a higher risk of 1-year MACCEs compared to SAVR.

Cardiovascular magnetic resonance for the assessment of patients undergoing transcatheter aortic valve implantation: a pilot study.

BACKGROUND: Before trans-catheter aortic valve implantation (TAVI), assessment of cardiac function and accurate measurement of the aortic root are key to determine the correct size and type of the prosthesis. The aim of this study was to compare cardiovascular magnetic resonance (CMR) and trans-thoracic echocardiography (TTE) for the assessment of aortic valve measurements and left ventricular function in high-risk elderly patients submitted to TAVI. METHODS: Consecutive patients with severe aortic stenosis and contraindications for surgical aortic valve replacement were screened from April 2009 to January 2011 and imaged with TTE and CMR. RESULTS: Patients who underwent both TTE and CMR (n = 49) had a mean age of 80.8 ± 4.8 years and a mean logistic EuroSCORE of 14.9 ± 9.3%. There was a good correlation between TTE and CMR in terms of annulus size (R2 = 0.48, p < 0.001), left ventricular outflow tract (LVOT) diameter (R2 = 0.62, p < 0.001) and left ventricular ejection fraction (LVEF) (R2 = 0.47, p < 0.001) and a moderate correlation in terms of aortic valve area (AVA) (R2 = 0.24, p < 0.001). CMR generally tended to report larger values than TTE for all measurements. The Bland-Altman test indicated that the 95% limits of agreement between TTE and CMR ranged from -5.6 mm to + 1.0 mm for annulus size, from -0.45 mm to + 0.25 mm for LVOT, from -0.45 mm2 to + 0.25 mm2 for AVA and from -29.2% to 13.2% for LVEF. CONCLUSIONS: In elderly patients candidates to TAVI, CMR represents a viable complement to transthoracic echocardiography.