Effects of hemoglobin levels on long-term prognosis in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Abstract

To evaluate the effects of hemoglobin (Hb) levels on long-term prognosis in the patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention. A total of 150 patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention between January 2005 to December 2007 were enrolled. They were divided into 2 groups: Hb < 120 g/L group (n = 21) and Hb ≥ 120 g/L group (n = 129). The mean clinical follow-up period was 3 years (range: 41.4 ± 16.1 months). The differences of major adverse cardiac events (MACE), including death, acute myocardial infarction, stent thrombosis & stent restenosis), were observed between two groups. The parameters of infarction site, infarction relative artery, 2-vessel disease, 3-vessel disease, Killip class ≥ II, drug-eluting stent, TIMI grade 3 flow, hypertension, hyperlipidemia, smoking, obesity, aspirin and clopidogrel use were not different between two groups (all P > 0.05). The rate of diabetes was significantly higher in Hb < 120 g/L group than that in Hb ≥ 120 g/L group (47.62% vs 18.60%, P = 0.0032). The mean age and symptom-onset-to balloon-time (SOTB) were significantly higher in Hb < 120 g/L group than that in Hb ≥ 120 g/L group (68.5 ± 9.2 vs 61.2 ± 12.2 years, P < 0.0001; 8.8 ± 10.5 vs 6.3 ± 5.0 h, P < 0.0001). The mean LVEF (left ventricular ejection fraction)(%) and rate of complete revascularization were significantly lower in Hb < 120 g/L group than that in Hb ≥ 120 g/L group (51.25 ± 11.34 vs 58.79 ± 10.38, P < 0.0001; 61.9% vs 86.8%, P = 0.0045). Logistic regression analysis showed that LVEF was an independent predictor of MACE during the follow-up period (P = 0.0140). During a 3-year follow-up, MACE occurred in 16 patients. The incidence of MACE was significantly higher in Hb < 120 g/L group than that in Hb ≥ 120 g/L group (33.33% vs 6.98%, P = 0.0003); Moreover the all-cause mortality and cardiac mortality were significantly higher in Hb < 120 g/L group than those in Hb ≥ 120 g/L group (28.57% vs 3.10%, P < 0.0001; 23.81% vs 2.33%, P < 0.0001). In the patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention, hemoglobin level < 120 g/L at baseline is markedly associated with adverse outcomes and an elevated incidence of MACE and mortality during the follow-up period.