Impact of hemoglobin levels at admission on outcomes among elderly patients with acute coronary syndrome treated with low-dose Prasugrel or clopidogrel: A sub-study of the ELDERLY ACS 2 trial

Age and gender mediated the association between anemia and 30-day outcomes in patients with ST-segment elevated myocardial infarction

Background

The higher prevalence of anemia in females and elderly may be attributed to its association with worsened outcomes in ST-elevation myocardial infarction (STEMI) patients. We aimed to evaluate the precise effects of age and gender on the association between anemia and 30-day outcomes.

Method

We identified 4350 STEMI patients and divided into anemia and non-anemia. Effects were analyzed as categories using Cox proportional-hazards regression and as continuous using restricted cubic splines. Propensity score matching (PSM) and mediation analysis were applied to identify intermediate effects.

Results

Anemic patients were older, more likely to be female, and experienced doubled all-cause death (7.3 % versus 15.0 %), main adverse cardiovascular and cerebrovascular events (MACCE, 11.1 % versus 20.2 %), heart failure (HF, 5.1 % versus 8.6 %), and bleeding events (2.7 % versus 5.4 %). After adjustment, the association between anemia and all-cause death (Hazard ratio (HR) 1.15, 95 % confidence interval (95 %CI) 0.93-1.14), MACCE (HR 1.14, 95 %CI 0.95-1.36) and HF (HR 1.19, 95 %CI 0.92-1.55) were insignificant, the effects persisted nullified across age classes (P-interaction > 0.05) and PSM (P > 0.05). Ulteriorly, age mediated 77.6 %, 66.2 %, 48.0 %, gender mediated 38.1 %, 15.0 %, 3.2 %, age and gender together mediated 99.8 % 72.9 %, 48.1 % of the relationship. Anemia was independently associated with bleeding events (HR 2.02, 95 %CI 1.42-2.88), the effects consisted significant regardless of PSM (P < 0.05), age, and gender classes (P-interaction > 0.05), and no mediating role of age and gender were observed.

Conclusions

In STEMI patients, age and gender largely mediated the relationship between anemia and all-cause death, MACCE, and HF, anemia was independently associated with bleeding complications.

Antiplatelet Strategies for Older Patients with Acute Coronary Syndromes: Finding Directions in a Low-Evidence Field

Patients ≥ 75 years of age account for about one third of hospitalizations for acute coronary syndromes (ACS). Since the latest European Society of Cardiology guidelines recommend that older ACS patients use the same diagnostic and interventional strategies used by the younger ones, most elderly patients are currently treated invasively. Therefore, an appropriate dual antiplatelet therapy (DAPT) is indicated as part of the secondary prevention strategy to be implemented in such patients. The choice of the composition and duration of DAPT should be tailored on an individual basis, after careful assessment of the thrombotic and bleeding risk of each patient. Advanced age is a main risk factor for bleeding. Recent data show that in patients of high bleeding risk short DAPT (1 to 3 months) is associated with decreased bleeding complications and similar thrombotic events, as compared to standard 12-month DAPT. Clopidogrel seems the preferable P2Y12 inhibitor, due to a better safety profile than ticagrelor. When the bleeding risk is associated with a high thrombotic risk (a circumstance present in about two thirds of older ACS patients) it is important to tailor the treatment by taking into account the fact that the thrombotic risk is high during the first months after the index event and then wanes gradually over time, whereas the bleeding risk remains constant. Under these circumstances, a de-escalation strategy seems reasonable, starting with DAPT that includes aspirin and low-dose prasugrel (a more potent and reliable P2Y12 inhibitor than clopidogrel) then switching after 2-3 months to DAPT with aspirin and clopidogrel for up to 12 months.

Association of hemoglobin levels with clinical outcomes in acute coronary syndromes in Koreans

Anemia is a well-known risk factor for cardiovascular disease. However, there are limited data on whether anemia on admission is a long-term prognostic factor in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention. We sought to evaluate the prevalence and prognostic consequences of anemia in patients with ACS treated with percutaneous coronary intervention in Korea. We retrospectively enrolled 1930 consecutive patients. Among the anemic population (hemoglobin [Hb] < 13 g/dL in men, and < 12 g/dL in women), we classified patients with Hb ≥ 7 g/dL, <10 d/dL as moderate anemia, other cases classified as mild anemia. Among patients with normal hemoglobin levels, we classified those with Hb > 16.5 g/dL in men, and > 16.0 g/dL in women, as having high hemoglobin. We examined the relationship between anemia with all-cause mortality and secondary outcomes - including cardiovascular mortality, myocardial infarction, stroke, and repeat revascularization. We classified 3.3%, 21.5%, and 5.3% of patients as moderate anemia, mild anemia, and high hemoglobin, respectively. During a median follow-up of 67.2 (interquartile range; 46.8-88.5) months, 74 (3.8%) patients died. Compared with patients with normal hemoglobin, we detected a significantly increased risk for all-cause mortality in patients with anemia (adjusted hazard ratios for moderate and mild anemia, respectively: 8.26 [95% confidence interval: 3.98-17.15], P < .001 and 2.60 [1.54-4.40], P < .001). Among patients with ACS, anemia is prevalent and is strongly associated with increased mortality and cardiovascular events. Clinical trials will prospectively evaluate the efficacy of treatment for anemia on the outcomes of patients with ACS.