Prevalence of iron deficiency in cardiac rehabilitation

Abstract

Iron deficiency (ID) is highly prevalent in patients with cardiovascular diseases (CVD), especially in heart failure (HF). Less is known on ID prevalence in cardiac rehabilitation (CR). To precise prevalence of ID in patient undergoing cardiac rehabilitation, and its impact on functional capacity (FC) and quality of life (QoL). Patients starting ambulatory CR program in our center were checked for ID, defined as ferritin < 100 ng/mL or < 300 ng/mL with transferin saturation (TSAT) < 20%. Functionnal capacity (FC) was defined in Watts with stress test, and QoL assessed with physical score (PS) and emotional score (ES) of SF-36. Left ventricular ejection fraction (LVEF) was tertilized as reduced (rEF < 40%), middly-reduced (mr-EF 40-49%) and preserved (pEF > 50%). Among the 211 patients included, mean age was 58 ± 13 years, and 165 (78%) were male. Main reason of CR referral was coronary artery disease (CAD). At baseline, prevalence of ID was 39% in all population, and equaly prevalent in the three categories of LVEF: rEF (35%), mrEF (38%) and pEF (40%) ( P = 0.9). Patients referred after cardiac surgery and HF episode presented most frequently with ID compared to CAD patients, respectively 61%, 46% and 31%. ( P = 0.01) ( Fig. 1 A). Compared to non-ID (NID) patients, ID patients had lower FC: 103W ± 33 versus (vs.) 114W ± 38 ( P = 0.02) ( Fig. 1 B) , and there was a trend toward lower PS and ES in ID compared to NID patients: respectively 40 ± 29 vs. 47 ± 24 ( P = 0.08) and 45 ± 33 vs. 52 ± 28 ( P = 0.1). Benefice of CR was higher in ID patients according to FC improvement (+21 ± 23% vs. + 15 ± 22%, P = 0.06), and PS et ES improvement were similar to non-ID patients: respectively +22 ±46% vs. +28 ± 45% ( P = 0.5) and +33 ± 67% vs. 23 ± 42% ( P = 0.3). ID is highly prevalent in patient undergoing CR program, especially after heart surgery and in HF. In ID patients, improvement of FC and QoL are respectively higher and similar to NID patients.