Serial pulmonary vascular resistance assessment in patients late after ventricular septal defect repair.

BACKGROUND: The long-term evolution of pulmonary vascular resistance (PVR) after ventricular septal defect (VSD) repair is unknown. This study serially evaluated resting and exercise PVR after VSD repair in childhood. METHODS: Patients were enrolled from the outpatient Adult Congenital Heart Disease clinic of the University Hospitals Leuven and compared to age- and gender-matched controls. Participants underwent resting and exercise echocardiography and cardiopulmonary exercise testing at baseline and follow-up. Total PVR was calculated as the ratio of mean pulmonary artery pressure (mPAP) to cardiac output (CO). The slope of the mPAP-CO curve (exercise PVR) was obtained using linear regression analysis. RESULTS: Twenty-seven patients (mean age 31 ±â€¯7 years, 70% male) and 18 controls were included. At baseline, patients had larger right ventricular (RV) end-diastolic areas (10 ±â€¯2 vs 9 ±â€¯1 cm2/m2, p = 0.001) and lower tricuspid annular plane systolic excursion (TAPSE) (17 (17-19) vs 26 (22-28) mm, p < 0.001). After 1.1 (1.0-1.5) years follow-up, similar differences in RV areas and TAPSE were found. Patients reached lower peak workload and cardiac index compared to controls at each time point. Peak total PVR was higher (Baseline: 2.7 ±â€¯0.8 vs 2.2 ±â€¯0.3 mm Hg/L/min, p = 0.005; Follow-up: 2.9 ±â€¯0.9 vs 2.1 ±â€¯0.3 mm Hg/L/min, p < 0.001) and the mPAP-CO slope was steeper (Baseline: 2.2 ±â€¯0.8 vs 1.7 ±â€¯0.3 mm Hg/L/min, p = 0.008; Follow-up: 2.5 ±â€¯0.9 vs 1.6 ±â€¯0.3 mm Hg/L/min, p < 0.001) in patients. The mPAP-CO slope in patients correlated inversely with peak oxygen uptake (R = -0.41 and - 0.45, p = 0.036 and 0.022, baseline and follow-up, respectively). CONCLUSION: Despite repair, VSD patients seem to show altered pulmonary hemodynamics and RV impairment at rest and exercise, supporting life-long follow-up.

Functional and haemodynamic assessment of mild-to-moderate pulmonary valve stenosis at rest and during exercise.

OBJECTIVE: In adult patients with mild-to-moderate pulmonary valve (PV) stenosis, exercise capacity and haemodynamics have not been extensively studied, although regular exercise is recommended. Therefore, we aimed to assess exercise capacity to study the increase in PV gradient during exercise and to evaluate the impact of this increased pressure load on the RV. METHODS: Nineteen patients (8 female; 29±6.4 years) with isolated mild-to-moderate PV stenosis and no prior cardiac interventions were consecutively enrolled from the outpatient clinic of adult congenital heart disease. All patients underwent cardiopulmonary exercise testing, transthoracic echocardiography and bicycle stress echocardiography. Results for exercise testing were compared with age-matched and gender-matched control patients. RESULTS: In the studied population, resting heart rate (89±11 vs 75±14 bpm; p=0.001), peak power (199±66 vs 263±68 W; p=0.006); peak VO2 (31.2±9.9 vs 39±7.4 mL/kg/min; p=0.011); oxygen uptake efficiency slope (2430±913 vs 3292±943(mL/min)/(L/min); p=0.007) and VE/VCO2 slope (26.8±5.2 vs 22.6±4.3; p=0.01) differed significantly from controls. A linear increase of peak PV gradient with increasing flow was observed in the pooled dataset (Pearson's R=0.947; p<0.0001) and slopes identical as for control patients were obtained for the oxygen pulse-workload relationship. Right heart morphology and function were preserved in the studied patients. CONCLUSIONS: Patients with mild-to-moderate PV stenosis have decreased exercise capacity. A linear increase in PV gradient with flow suggests a fixed valve area throughout the exercise. Although systolic RV pressure load increases during exercise, good ventricular performance was observed without signs of functional or morphological changes of the right heart. CLINICAL TRIAL NUMBER: NCT01444222.