Introduction:
In non-ST-segment elevation acute coronary syndrome (NSTE-ACS), ST-elevation in lead aVR (ST↑aVR) on admission ECG has been shown to be associated with severe coronary artery disease, but its impact on long-term clinical outcomes is unclear.
Methods:
We studied 454 patients with NSTE-ACS who underwent coronary angiography during initial hospitalization. Patients were divided into the 3 groups according to the degree of ST↑aVR on admission ECG: no ST↑aVR (n=301, G-A); ST↑aVR <1.0 mm (n=82, G-B); and ST↑aVR ≥1.0 mm (n=71, G-C). Troponin T (TnT), hemoglobin (Hb), estimated glomerular filtration rate (eGFR), brain natriuretic peptide (BNP), high-sensitivity C-reactive protein (hsCRP), TIMI risk score, and summed ST-segment depression in other leads were also measured on admission.
Results:
There were no differences in sex or coronary risk factors except for diabetes mellitus in the 3 groups. In G-A, G-B, and G-C, age was 66±11, 68±11, and 70±11 years; the rates of diabetes mellitus were 30%, 48%, and 51%; Killip class ≥2 was 7%, 20%, and 34%; positive TnT was 30%, 46%, and 56%; TIMI risk score was 2.8±1.4, 3.6±1.3, and 3.8±1.2; the levels of Hb were 13.4±1.9, 13.2±1.9, and 12.2±2.3 g/dl; eGFR was 65±24, 59±27, and 53±28 ml/min/1.73 m2; BNP was 155±249, 386±338, and 455±507 pg/ml; hsCRP was 0.339±1.499, 0.654±1.899, and 0.842±1.788 mg/dl; summed ST-segment depression was 2.0±2.6, 5.6±3.5, and 13.0±6.6 mm; the rates of left main or 3-vessel disease were 9%, 44%, and 75%; and major adverse events (death, [re]infarction, urgent revascularization, or heart failure requiring hospitalization) at 5 years were 19%, 43%, and 58%, respectively (all p<0.01). After adjusting for baseline characteristics, multivariate analysis showed that as compared with no ST↑aVR, the hazard ratios (95% CI) for 5-year adverse events associated with ST↑aVR <1.0 mm and ST↑aVR ≥1.0 mm were 2.16 (1.10-5.59; p=0.019) and 3.90 (1.44-9.76; p=0.001), respectively.
Conclusions:
In patients with NSTE-ACS, greater ST↑aVR on admission ECG strongly predicted 5-year adverse outcomes, even after adjusting for traditional risk factors, biomarker profiles, and ST-segment depression in other leads. Our findings suggest the importance of ST↑aVR in risk stratification for NSTE-ACS.