Background Anemia and blood loss occur often in patients with ST-segment-elevation myocardial infarction (STEMI). In-hospital hemoglobin drop is associated with 1-year mortality in patients with acute coronary syndrome. However, data on the effect of hemoglobin reduction on myocardial salvage and long-term outcomes are scarce. We investigated the impact of in-hospital hemoglobin drop on myocardial salvage and 5-year mortality in patients with STEMI treated with primary percutaneous coronary intervention. Methods and Results In-hospital hemoglobin drop was defined as a decrease in hemoglobin levels from admission and nadir hemoglobin values. Patients were categorized as having the following: no drop, minimal drop (<3 g/dL), minor drop (≥3 to <5 g/dL), and major drop (≥5 g/dL). Myocardial area at risk and infarct size were measured using serial single-photon emission computerized tomography imaging. The co-primary outcomes were myocardial salvage and 5-year all-cause mortality. Of 1204 patients, 1169 (97.1%) showed a hemoglobin drop during hospitalization: minimal, minor, and major drop occurred in 894 (74.3%), 214 (17.8%), and 61 (5.1%) patients, respectively. Myocardial salvage was reduced in patients with minimal (median, 0.53 [interquartile range, 0.27-0.83]), minor (median, 0.40 [interquartile range, 0.18-0.62]), and major (median, 0.40 [interquartile range, 0.14-0.77]) drop compared with patients without drop (median, 0.70 [interquartile range, 0.44-1.0], P<0.001). After adjusting for covariates, hemoglobin drop remained an independent correlate of poor myocardial salvage. A drop of ≥3 g/dL was associated with reduced left ventricular function at 6 months and with increased mortality at 5-year follow-up after STEMI. Conclusions In patients with STEMI undergoing primary percutaneous coronary intervention, in-hospital hemoglobin drop was associated with reduced myocardial salvage, left ventricular function, and increased long-term mortality.
Keywords: blood loss; hemoglobin; infarct size; myocardial infarction; single‐photon emission computed tomography imaging.