Low homoarginine increases risk for cardiac death
MedWire News: Homoarginine deficiency significantly increases risk for fatal cardiovascular (CV) events in coronary angiography patients, a study suggests.
"In 3305 patients referred for coronary angiography, we have shown that low homoarginine concentrations are associated with impaired left ventricular (LV) function, reduced circulating variables of energy metabolism, and an increased risk of fatal events," write Stefan Pilz (Medical University of Graz, Austria) and colleagues in the journal Heart.
The study involved 3305 patients referred for coronary angiography between 1997 and 2000. The mean serum homoarginine concentration of the cohort was 2.42 µmol/l.
The team followed-up the patients over a median period of 9.9 years for specific causes of death, including CV causes, sudden cardiac death (SCD), heart failure (HF), fatal myocardial infarction (MI), coronary artery disease interventions, and other cardiac causes.
The findings revealed that serum homoarginine concentration positively correlated with angiographic ejection fraction and inversely correlated with N-terminal pro-B-type natriuretic peptide NT-pro-BNP (p<0.001 for both).
In addition, homoarginine positively correlated with energy metabolism variables guanidinoacetate and creatinine (p<0.001 for both).
Overall, 991 patients died, including 148 from HF, 105 from MI, and 258 from SCD.
Serum homoarginine levels across the first to the fourth quartile were <1.84, 1.84-2.42, 2.43-3.09, and >3.09 µmol/l.
Multivariate analysis adjusted for potential confounders including age, sex, and guanidinoacetate levels showed that patients with the highest serum homoarginine concentration (fourth quartile) had a 2.44-fold increased risk for SCD, 3.44-fold increased risk for dying from HF, and 3.78-fold increased risk for fatal MI compared with those with the lowest concentration (first quartile).
"Low homoarginine concentrations, independent of established CV risk factors, were strongly predictive of fatal CV events," explain the authors.
"Further studies are urgently needed to confirm our results and to evaluate whether homoarginine metabolism is a promising target for risk stratification and therapeutic approaches for CV disease," they conclude.
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By Piriya Mahendra