Randomized Comparison of High-Sensitivity Troponin Reporting in Undifferentiated Chest Pain Assessment

Background—

High-sensitivity troponin T (hs-TnT) assays promise greater discrimination of evolving myocardial infarction, but the impact of unguided implementation on the effectiveness of care is uncertain.

Methods and Results—

We evaluated the impact of hs-TnT reporting on care and outcome among chest pain patients presenting to 5 emergency departments within a multicenter randomized trial. Patients were allocated to hs-TnT reporting (hs-report) or standard reporting (std-report; Roche Elecys). The primary end point was death and new or recurrent acute coronary syndrome by 12 months. A total of 1937 patients without ST-segment elevation were enrolled between July 2011 and March 2013. The median age was 61 (interquartile range, 48–74) years, and 46.3% were women. During the index hospitalization, 1466 patients (75.7%) had maximal troponin <30 ng/L within 24 hours. Randomization to hs-report format did not alter the admission rate (hs-report: 57.7% versus std-report: 58.0%; P =0.069). There was no difference in angiography (hs-report: 11.9% versus std-report: 10.9%; P =0.479). The hs-reporting did not reduce 12-month death or new/recurrent acute coronary syndrome in the overall population (hs-report: 9.7% versus std-report: 7.2% [hazard ratio, 0.83 (0.57–1.22); P =0.362]). However, among those with troponin levels <30 ng/L, a modest reduction in the primary end point was observed (hs-report: 2.6% versus std-report: 4.4%, [hazard ratio, 0.58; 95% confidence interval, 0.34–0.1.00; P =0.050).

Conclusions—

High-sensitivity troponin reporting alone is associated with only modest changes in practice. Clinical effectiveness in the adoption of high-sensitivity troponin may require close coupling with protocols that guide interpretation and care.

Clinical Trial Registration—

URL: http://www.ANZCTR.org.au . Unique identifier: ACTRN12611000879965.

Patients with non-ST-elevation acute coronary syndromes undergoing coronary artery bypass grafting in the modern era of antithrombotic therapy

BACKGROUND

Many high-risk patients with non-ST-elevation acute coronary syndromes within the SYNERGY trial required coronary artery bypass grafting (CABG) for optimal revascularization. We explored the clinical outcomes among high-risk patients undergoing CABG and the impact of modern pharmacology.

METHODS

We evaluated 180-day rates of death and myocardial infarction (MI) and 30-day GUSTO severe bleeding among patients undergoing CABG, contrasting them with patients undergoing percutaneous coronary intervention (PCI) or medical management. The relationships between perioperative MI, bleeding events, and 6-month mortality were explored. The effect of random assignment to unfractionated heparin or enoxaparin and the relationships between use of clopidogrel and glycoprotein IIb/IIIa inhibitors and clinical outcomes were assessed.

RESULTS

Death or MI at 6 months was more common among patients requiring CABG (CABG 31.2%, PCI 15.9%, medical 9.9%). Thirty-day GUSTO severe bleeding was also higher (CABG 6.4%, PCI 1.1%, medical 0.9%). Perioperative MI and GUSTO severe bleeding were associated with excess 6-month mortality (hazard ratio 2.1, 95% CI 1.27-3.53 and hazard ratio 7.6, CI 4.78-12.09, respectively). Randomization to enoxaparin was not associated with an increase in bleeding or a reduction in death or MI. No differences in ischemic outcomes were observed among patients given glycoprotein IIb/IIIa inhibition or clopidogrel.

CONCLUSIONS

High-risk patients still commonly require CABG with greater bleeding and ischemic event rates observed. Current definitions of perioperative MI and GUSTO severe bleeding portend an increased in 6-month mortality among CABG patients. Modern pharmacotherapies do not appear to impact these higher event rates.

Long-term outcomes of left bundle branch block in high-risk survivors of acute myocardial infarction: The VALIANT experience

BACKGROUND

In survivors of myocardial infarction (MI), new left bundle branch block (LBBB) is associated with adverse outcomes, but its impact is not well described in post-MI patients with left ventricular (LV) systolic dysfunction and/or heart failure (HF).

OBJECTIVES

The aim of this study was to determine if new LBBB is an independent predictor of long-term fatal and nonfatal outcomes in high-risk survivors of MI by reviewing data from the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial.

METHODS

In VALIANT, 14,703 patients with LV systolic dysfunction and/or HF were randomized to valsartan, captopril, or both a mean of 5 days after MI. Baseline ECG data were available from 14,259 patients. We assessed the predictive value of new LBBB for death and major cardiovascular outcomes after 3 years, adjusting for multiple baseline covariates including LV ejection fraction.

RESULTS

At follow-up, patients with new LBBB (608 [4.2%]) compared with patients without new LBBB had more comorbidities and increased adjusted risk of death (hazard ratio [HR] 1.3, 95% confidence interval [CI] 1.2-1.6), cardiovascular death (HR 1.4, 95% CI 1.2-1.7), HF (HR 1.3, 95% CI 1.1-1.6), MI (HR 1.5, 95% CI 1.2-1.9), and the composite of death, HF, or MI (HR 1.4, 95% CI 1.2-1.6).

CONCLUSION

In post-MI survivors with LV systolic dysfunction and/or HF, new LBBB was an independent predictor of all major adverse cardiovascular outcomes during long-term follow-up. This readily available ECG marker should be considered a major risk factor for long-term cardiovascular complications in high-risk patients after MI.