Use of intravenous iron in cyanotic patients with congenital heart disease and/or pulmonary hypertension.

BACKGROUND: Secondary erythrocytosis is common in patients with cyanosis secondary to congenital heart disease (CHD) and/or pulmonary hypertension (PH). This compensatory mechanism aims at increasing oxygen delivery to the tissues, but it requires adequate iron stores. Optimal methods of iron supplementation in this setting remain controversial, with fears of excessive erythropoiesis and hyperviscosity symptoms. We describe our experience using intravenous ferrous carboxymaltose. METHODS AND RESULTS: 142 consecutive cyanotic patients were treated over 5.7 years (201 administrations). Mean age was 51.3 ±â€¯17.6 years and 55 (38.7%) were male. Eisenmenger syndrome (ES) was present in 41 (28.8%), other pulmonary arterial hypertension (PAH) related to CHD (PAH-CHD) in 27 (19.0%), cyanotic CHD without PAH in 16 (11.3%) and PH without CHD in 58(40.8%). Baseline haemoglobin (Hb) concentration was 14.6 ±â€¯3.0 g/dL and haematocrit 0.45 ±â€¯0.09. A 500 mg dose of intravenous (IV) iron carboxymaltose was given in 163 (81.1%) of administrations and a 1000 mg dose in 37 (18.4%). A significant improvement in average Hb, haematocrit, ferritin and transferrin saturation was observed after a median follow-up of 100.0 [70.0-161.0] days (p ≤ 0.0001 for all). There were no cases of excessive erythropoiesis resulting in new hyperviscosity symptoms and/or requiring venesection. A minor transient rash was observed in 2 patients and one patient experienced an air embolus causing a transient ischemic attack. CONCLUSIONS: Intravenous ferrous carboxymaltose appears to be safe in iron deficient patients with cyanosis due to CHD and/or PH, as long as care is taken to avoid air emboli. Further randomised studies are needed to confirm the safety and efficacy of intravenous iron in this setting.

Biventricular dyssynchrony on cardiac magnetic resonance imaging and its correlation with myocardial deformation, ventricular function and objective exercise capacity in patients with repaired tetralogy of Fallot.

BACKGROUND: Electrical dyssynchrony and prolonged QRS duration are common in patients with repaired tetralogy of Fallot (ToF). It has been linked to increased risk of sudden cardiac death and right ventricular (RV) dysfunction. We investigated myocardial dyssynchrony using cardiac magnetic resonance imaging (CMR) and feature tracking analysis (FT) in this setting and compared it to myocardial deformation, conventional parameters of ventricular dysfunction and clinical parameters. METHODS AND RESULTS: Patients underwent standardized CMR investigations as part of a nationwide study. We prospectively assessed myocardial deformation and analysed regional wall motion abnormalities of the RV and the left ventricle (LV) using CMR-FT. The main measure of dyssynchrony was the maximal time difference (wall motion delay) of the regional strain as a parameter of mechanical biventricular dyssynchrony. In addition, clinical parameters and measures of cardiopulmonary exercise capacity were available. Overall 345 patients were included. Parameters of biventricular wall motion delay correlated significantly with global FT-strain parameters (p < 0.0001 for all imaging planes assessed). Furthermore, we found a significant correlation between circumferential RV motion delay and QRS duration (p = 0.006). Higher LV and RV wall motion delay parameters were also associated with lower peak oxygen consumption (p < 0.05) and a worse LV and RV ejection fraction (p < 0.02). CONCLUSIONS: Assessment of mechanical dyssynchrony is feasible using CMR-FT in ToF patients. Parameters of mechanical dyssynchrony correlate with electrical dyssynchrony, biventricular function and objective exercise capacity in this setting. Due to the weak degree of correlation, however, the clinical significance of these findings remains to be clarified by further studies.