Prevalence and outcomes of iron deficiency (summary of findings table)
| Study | Sample size (HFpEF) | % women | Ejection fraction cut-off for HFpEF | Average age (years) | Prevalence of iron deficiency | Outcome measures | Outcome | ||
| Total | Absolute | Functional | |||||||
| Araujo, 201529 | 117 | 69.8 | ≥50% | 74.95±11.8 | 31.4% | – | – | Nil (prevalence only) | NA |
| Barandiaran, 201740 | 115 | 67.8 | ≥50% | – | 50% | – | – | Nil (prevalence only) | NA |
| Bekfani, 201541 | 233 | – | ≥50% | 71±9 | 56% | 46.8% | 9.2% | Peak VO2 Exercise time 6MWT EQ-5D questionnaire | Ferritin positively correlated with peak VO2, r=0.28, p=0.03 Exercise time negatively correlated with ferritin r=0.31, p=0.01 416±125 m IR, 367±138 m ID, p=0.05 Ferritin correlated positively with distance walked r=0.24, p=0.01 19062±4704 IR, 16373±5304 ID, p<0.05 |
| Borut Jug, 201625 | 220 | – | Not described | – | – | – | – | Death or hospitalisation (composite) | OR 1.88 (0.917–3.861), p=0.085 for iron-deficient patients Adjusted for age, gender, NYHA class, ischaemic aetiology, natriuretic peptides, renal function, anaemia |
| Carmo, 201444 | 47 | – | Not described | 78.9±9.2 | 72.3% | – | – | Nil (prevalence only) | NA |
| Fitzsimons*, 2015/201626 27 | 280 | 45% | ≥50% | 73.8 | 64% | 23% | 41% | Death | HR 0.98 (0.53–1.81), p=0.95 for iron-deficient patients |
| Kasner, 201319 | 26 | 42% | Not described | 55±8.5 | 58% | 35% | 23% | NT-proBNP levels (pg/mL) VO2 (mL/min/kg) Exercise performance (W) | NT-proBNP 192±199 ID vs 169±109, p=0.095 17±1.5 ID vs 18±3 IR, p=0.93 102±25 ID vs 121±50 IR, p=0.49 Analyses were not adjusted but patients had similar baseline characteristics |
| Lainscak, 201542 | 207 | 42% | ≥50% | 71±12 | 56% | – | – | Nil (prevalence only in HFpEF) | NA |
| Martens, 201720 | 72 | – | ≥50% | – | 64% | – | – | VO2 (mL/min/kg) All-cause mortality and hospitalisation | 16±5 IR, 9±2 ID, p<0.001 Significantly higher in ID vs IR, p=0.001, adjusted for age, gender, implantable cardioverter defibrillator use, CRT use, ischaemic aetiology, medication use and baseline LVEF |
| Nieto Sandoval, 201728 | 139 | 65.3% | ≥50% | 79.8±8 | 67% | 19% | 48% | Death | Higher ferritin associated with increased mortality in HFpEF (statistics not quoted) |
| Nunez, 201622 | 40 | 55% | ≥50% | 74±5.5 | 70% | – | – | VO2 | Log VO2 correlated with TSAT (r=0.46, p=0.003) and ferritin (r=0.30, p=0.048) in HFpEF Adjusted for gender, HR, NT-proBNP, eGFR, E/e′, Hb, TAPSE |
| Orynchak, 201423 | 79 | 65% | ≥50% | 53±8 | – | – | – | NYHA class | NYHA class II/III associated with lower serum iron, ferritin and transferrin regardless of anaemia status |
| Yeo, 201443 | 154 | – | ≥50% | – | – | – | 61% | Nil (prevalence only for HFpEF) | NA |
| Yeo, 2014†24 | 148 | – | ≥50% | – | 60.1% | – | – | MLHFQ NYHA functional class | Patients with FID had worse MLHFQ compared with IR (28 vs 36, p<0.05) Patients with FID had no difference in NYHA class compared with IR (1.85 vs 2, p=0.16) |
*Fitzsimons et al had two papers reporting on the same cohort, therefore information on this cohort was gathered from the two publications and reported as the same population in our summary of findings table.
†Yeo et al did not use a standard definition of iron deficiency: they defined iron deficiency as transferrin saturation <20%, without any criteria for ferritin.
CRT, cardiac resynchronisation therapy; FID, functional iron deficiency; HFpEF, heart failure with preserved ejection fraction; ID, iron deficient; IR, iron replete; LVEF, left ventricular ejection fraction; MLHFQ, Minnesota Living with Heart Failure Questionnaire; 6MWT, 6 min walk test; NA, not available; NYHA, New York Heart Association; TAPSE, tricuspid annular plane systolic excursion; TSAT, transferrin saturation.