Lowered anti-beta1 adrenergic receptor antibody concentrations may have prognostic significance in acute coronary syndrome

Although several risk factors exist for acute coronary syndrome (ACS) no biomarkers for survival or risk of re-infarction have been validated. Previously, reduced serum concentrations of anti-ß₁AR Ab have been implicated in poorer ACS outcomes. This study further evaluates the prognostic implications of anti-ß₁AR-Ab levels at the time of ACS onset. Serum anti-ß₁AR Ab concentrations were measured in randomly selected patients from within the PLATO cohort. Stratification was performed according to ACS event: ST-elevation myocardial infarct (STEMI) vs. non-ST elevation myocardial infarct (NSTEMI). Antibody concentrations at ACS presentation were compared to 12-month all-cause and cardiovascular mortality, as well as 12-month re-infarction. Sub-analysis, stratifying for age and the correlation between antibody concentration and conventional cardiac risk-factors was subsequently performed. Serum anti-ß₁AR Ab concentrations were measured in 400/799 (50%) STEMI patients and 399 NSTEMI patients. Increasing anti-ß₁AR Ab concentrations were associated with STEMI (p = 0.001). Across all ACS patients, no associations between anti-ß₁AR Ab concentration and either all-cause cardiovascular death or myocardial re-infarction (p = 0.14) were evident. However among STEMI patients ≤60 years with anti-ß₁AR Ab concentration <median higher rates of re-infarction were observed, compared to those with anti-ß₁AR Ab concentrations > median (14/198 (7.1%) vs. 2/190 (1.1%)); p = 0.01). Similarly, the same sub-group demonstrated greater risk of cardiovascular death in year 1, including re-infarction and stroke (22/198 (11.1%) vs. 10/190 (5.3%); p = 0.017). ACS Patients ≤60 years, exhibiting lower concentrations of ß₁AR Ab carry a greater risk for early re-infarction and cardiovascular death. Large, prospective studies quantitatively assessing the prognostic relevance of Anti-ß₁AR Ab levels should be considered.