Anemia Associated With Higher Mortality Rates in Acute Coronary Syndrome

For patients with acute coronary syndrome (ACS) treated with percutaneous coronary intervention (PCI), baseline anemia was associated with a higher risk for mortality, myocardial reinfarction, and major bleeding, according to study results published in the Journal of the American Heart Association.

The aim of this study was to assess the relationship among baseline anemia and ischemic events, bleeding events, and mortality among patients enrolled in the VALIDATE-SWEDEHEART trial, who were treated mainly with P2Y₁₂ inhibitors during PCI for ACS. VALIDATE-SWEDEHEART was a registry-based, prospective, randomized clinical trial that assessed the efficacy and safety of heparin therapy vs bivalirudin therapy. Baseline anemia was defined as a hemoglobin value <130 g/L for men and <120 g/L for women. The primary endpoint was death from any cause at 180 days. Secondary endpoints were myocardial reinfarction, major bleeding, definite stent thrombosis, and stroke at 180 days. The data was recorded at baseline, 7 days after PCI, and 180 days after PCI.

Of the 5482 patients included in this study, 14.4% had baseline anemia. This cohort with baseline anemia was older; had lower body mass indices; had more incidents of kidney dysfunction, hyperlipidemia, hypertension, diabetes mellitus, coronary artery disease, stroke, or heart failure; and were less frequently treated with potent P2Y₁₂ inhibitors than the cohort without baseline anemia (P <.001 for all). The cohort with baseline anemia had a higher risk for 180-day mortality rate (hazard ratio [HR] 1.9; 95% CI, 1.3-2.7; P <.001), myocardial reinfarction (HR 1.7; 95% CI, 1.1-2.7; P =.013), and a major bleeding event (HR 1.3; 95% CI, 1-1.6; P =.041) than the cohort without baseline anemia. At 7 days post-PCI, both mortality (P <.001) and major bleeding (P =.026) were higher in the cohort with baseline anemia. Patients with severe anemia with hemoglobin values <100 g/L had an almost 10-times higher mortality rate, a 6-times higher rate of myocardial reinfarction, and a 3 times higher rate of a major bleeding event than patients with normal hemoglobin levels.

Limitations of this study include the inability to assess causality because of the observational nature of the study, the lack of background information with regard to the cause of anemia and other potential confounding variables, and the possible effects diuretics and infusions have on hemoglobin levels.

The researchers concluded that “anemia constitutes a high-risk feature in patients with [ACS] despite treatment with contemporary therapies.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Wester A, Attar R, Mohammad MA, et al. Impact of baseline anemia in patients with acute coronary syndromes undergoing percutaneous coronary intervention: a prespecified analysis from the VALIDATE-SWEDEHEART trial. J Am Heart Assoc. 2019;8:e012741.