Safety and efficacy of the 0 h/3 h protocol for rapid rule out of myocardial infarction.

BACKGROUND: The early and accurate diagnosis of acute myocardial infarction (AMI) is an important medical and economic challenge. We aimed to prospectively evaluate the performance of the new European Society of Cardiology rapid 0-hour/3-hour (0 h/3 h) rule out protocol for AMI. METHODS: We enrolled 2,727 consecutive patients presenting with suspected AMI without persistent ST-segment elevation to the emergency department in a prospective international multicenter study. The final diagnosis was adjudicated by 2 independent cardiologists. The performance of the 0 h/3 h rule out protocol was evaluated using 4 high-sensitivity (primary analysis) and 3 sensitive cardiac troponin (cTn) assays. RESULTS: Acute myocardial infarction was the final diagnosis in 473 patients (17.3%). Using the 4 high-sensitivity cTn assays, the 0-hour rule out protocol correctly ruled out 99.8% (95% [confidence interval] CI, 98.7%-100%), 99.6% (95% CI, 98.5%-99.9%), 100% (95% CI, 97.9%-100%), and 100% (95% CI, 98.0%-100%) of late presenters (>6 h from chest pain onset). The 3-hour rule out protocol correctly ruled out 99.9% (95% CI, 99.1%-100%), 99.5% (95% CI, 98.3%-99.9%), 100% (95% CI, 98.1%-100%), and 100% (95% CI, 98.2%-100%) of early presenters (<6 h from chest pain onset). Using the 3 sensitive cTn assays, the 0-hour rule out protocol correctly ruled out 99.6% (95% CI, 98.6%-99.9%), 99.0% (95% CI, 96.9%-99.7%), and 99.1% (95% CI, 97.2%-99.8%) of late presenters; and the 3-hour rule out protocol correctly ruled out 99.4% (95% CI, 98.3%-99.8%), 99.2% (95% CI, 97.3%-99.8%), and 99.0% (95% CI, 97.2%-99.7%) of early presenters. Overall, the 0 h/3 h rule out protocol assigned 40% to 60% of patients to rule out. None of the patients assigned rule out died during 3-months follow-up. CONCLUSIONS: The 0 h/3 h rule out protocol seems to allow the accurate rule out of AMI using both high-sensitivity and sensitive cTn measurements in conjunction with clinical assessment. Additional studies are warranted for external validation.

Clinical utility of circulating interleukin-6 concentrations in the detection of functionally relevant coronary artery disease.

BACKGROUND: Inflammation plays a major role in the pathogenesis of coronary artery disease (CAD). METHODS: We hypothesized, that quantifying inflammation by measuring circulating interleukin-6 concentrations help in the diagnosis and/or prediction of functionally relevant CAD. Among consecutive patients with symptoms suggestive of CAD, functionally relevant CAD was adjudicated in two domains: first, diagnosis according to myocardial perfusion single photon emission tomography (MPI-SPECT) and coronary angiography; second, cardiovascular death and all-cause death during 2-years follow-up. Adjudication was done blinded to the interleukin-6 concentrations. RESULTS: Among 1553 patients, symptoms were adjudicated to be causally related to CAD in 43% (665/1553). Interleukin-6 concentrations were higher in patients with functionally relevant CAD as compared to those without (1.56 pg/mL versus 1.30 pg/mL, p < 0.001), but overall had only low-to-modest diagnostic accuracy (area under the curve [AUC]: 0.57, 95%CI 0.55-0.61) and were no independent predictor of functionally relevant CAD after multivariable adjustment (p = 0.068). Interleukin-6 concentrations had moderate-to-high accuracy in the prediction of cardiovascular death (AUC 0.75, 95%CI 0.69-0.82) and all-cause death (AUC 0.72, 95%CI 0.66-0.78) at 2-years, and remained a significant predictor after multivariable adjustment (p < 0.001). Compared to patients with interleukin-6 concentrations below the median (1.41 pg/mL), patients with concentrations above the median had a significantly higher cumulative incidence of cardiovascular death (1% vs. 4%, log-rank p < 0.001) and all-cause death (2% vs. 8%, log-rank p < 0.001) at 2 years. CONCLUSION: Interleukin-6 concentrations are strong and independent predictors of cardiovascular death and all-cause death.