Clinical implications of a next-day follow-up electrocardiogram in patients with non-ST elevation acute coronary syndromes

Predictive Value of Serial ECGs in Patients with Suspected Myocardial Infarction

The electrocardiogram (ECG) is an important diagnostic tool for patients with suspected acute myocardial infarction (AMI). Current guidelines recommend serial ECGs in case of persisting symptoms. We aimed to analyze the predictive value of ischemic ECG-signs in patients with suspected AMI. Patients presenting to the emergency department with suspected AMI were included. All patients with ST-elevation AMI were excluded from analyses. Patients received 12-lead-ECG and high-sensitive Troponin T (hs-TnT)-measurement at admission and after 3 h. Four groups were defined: no ischemic signs in either ECG; new ischemic signs in the second ECG; resolved ischemic signs in the second ECG; and persistent ischemic signs in both ECGs. Patients were followed for 2 years to assess the composite endpoint of all-cause-mortality, AMI, and coronary revascularization. Using a 30-day landmark analysis, a Cox regression with ischemic signs as the variable of interest, adjusted by cardiovascular risk factors, was calculated. Of 1675 patients, 1321 showed no ischemic signs, in 25 new-, in 92 resolved- and in 237 patients, persistent ischemic signs were documented. Patients with persistent ischemic signs had significantly worse outcomes, compared to those without. Compared to no ischemic signs, adjusted hazard ratios for the combined endpoint were 0.81 (95% CI 0.20, 3.31; p-value = 0.77) for new-, 0.59 (95% CI 0.26, 1.34; p-value = 0.21) for resolved-, and 1.47 (95% CI 1.102, 2.13; p-value = 0.041) for persistent ischemic signs. In patients with suspected AMI, persistent ischemic ECG-signs are predictive of a higher rate of all-cause-mortality, AMI, and revascularization.

Prognostic implications of prominent R wave in electrocardiographic leads V1 or V2 in patients with acute coronary syndrome

Although the adverse prognosis of Q-waves on electrocardiogram (ECG) has been demonstrated, the prognostic significance of prominent R wave (PRW) in V1 or V2 across a broad spectrum of acute coronary syndrome (ACS) has not been specifically studied. In the Global Registry of Acute Coronary Events (GRACE) and the Canadian ACS Registry I ECG substudies, admission ECGs were analyzed in an independent core ECG laboratory. PRW was defined as R wave >40 to 50 ms in V1 or V2, R/S ≥1 in V1, or R/S ≥1.5 in V2. Among 11,895 patients with ACS, 495 (4.2%) had PRW; they were less likely to have a history of hypertension or heart failure and had lower GRACE risk scores, but a higher incidence of ST-segment depression (all p ≤0.001). Patients with PRW had similar rates of in-hospital death (2.8% vs 4.1%, respectively, p = 0.15) but lower rates of in-hospital heart failure (8.5% vs 15.2%, respectively, p = 0.02) and 6-month mortality (4.6% vs 8.4%, respectively, p = 0.004). In multivariable analyses, PRW was not a significant independent predictor of in-hospital mortality (adjusted odds ratio = 0.99, 95% confidence interval 0.55 to 1.8) or 6-month mortality (adjusted odds ratio = 0.70, 95% confidence interval 0.43 to 1.15). Among 4,418 patients who underwent coronary angiography, those with PRW had a higher prevalence of left circumflex artery disease (62.5% vs 49.5%, respectively, p = 0.01). In conclusion, across the broad spectrum of patients with ACS, PRW provides no significant additional prognostic utility beyond comprehensive risk assessment using the GRACE risk score. PRW is more frequently associated with left circumflex artery disease.