Diagnosis of acute myocardial infarction in patients with renal failure using high-sensitivity cardiac troponin T.

BACKGROUND: Diagnosing myocardial infarction (MI) in patients with chronic kidney disease (CKD) is difficult as they often have increased high-sensitivity cardiac troponin T (hs-cTnT) concentrations. METHODS: Observational U.S. cohort study of emergency department (ED) patients undergoing hs-cTnT measurement. Cases with >1 hs-cTnT increase >99th percentile were adjudicated following the Fourth Universal Definition of MI. Diagnostic performance of baseline and serial 2-hour hs-cTnT thresholds for ruling-in acute MI was compared between those without and with CKD (eGFR <60 ml/min/1.73m2). RESULTS: The study cohort included 1992 patients, amongst whom 501 (25%) had CKD. There were 75 (15%) and 350 (70%) patients with CKD and 80 (5%) and 351 (24%) without CKD who had acute MI and myocardial injury. In CKD patients with baseline hs-cTnT thresholds of >52, >100, >200 or >300 ng/L, PPVs for MI were 36% (95% CI 28-45), 53% (95% CI 39-67), 73% (95% CI 50-89) and 80% (95% CI 44-98), and in those without CKD, 61% (95% CI 47-73), 69% (95% CI 49-85), 59% (95% CI 33-82) and 54% (95% CI 25-81). In CKD patients with a 2-hour hs-cTnT delta of >10, >20 or >30 ng/L, PPVs were 66% (95% CI 51-79), 86% (95% CI 68-96) and 88% (95% CI 68-97), and in those without CKD, 64% (95% CI 50-76), 73% (95% CI 57-86) and 75% (95% CI 58-88). CONCLUSION: Diagnostic performance of standard baseline and serial 2-hour hs-cTnT thresholds to rule-in MI is suboptimal in CKD patients. It significantly improves when using higher baseline thresholds and delta values.

High Baseline High-Sensitivity Cardiac Troponin T Concentrations and Risk of Index Acute Myocardial Infarction.

OBJECTIVE: To evaluate the diagnostic performance of the previously recommended baseline high-sensitivity cardiac troponin T (hs-cTnT) thresholds of 52 and 100 ng/L in identifying patients at high risk of acute myocardial infarction (AMI). PATIENTS AND METHODS: This study compared the positive predictive value (PPV) for index AMI of these high-risk hs-cTnT thresholds in adult patients in the emergency department undergoing hs-cTnT measurement. RESULTS: The adjudicated MAyo Southwest Wisconsin 5th Gen Troponin T ImplementatiON cohort included 2053 patients, with 157 (7.6%) who received a diagnosis of AMI. The hs-cTnT concentrations of greater than 52 and greater than 100 ng/L resulted in PPVs of 41% (95% CI, 35%-48%) and 57% (95% CI, 48%-66%). In patients with chest discomfort, hs-cTnT concentrations greater than 52 ng/L resulted in a PPV of 66% (95% CI, 56%-76%) and hs-cTnT concentrations greater than 100 ng/L resulted in a PPV of 77% (95% CI, 65%-87%). The CV Data Mart Biomarker cohort included 143,709 patients, and 3003 (2.1%) received a diagnosis of AMI. Baseline hs-cTnT concentrations greater than 52 and greater than 100 ng/L resulted in PPVs of 12% (95% CI, 11%-12%) and 17% (95% CI, 17%-19%), respectively. In patients with chest pain and hs-cTnT concentrations greater than 52 ng/L, the PPV for MI was 17% (95% CI, 15%-18%) and in those with concentrations greater than 100 ng/L, only 22% (95% CI, 19%-25%). CONCLUSION: In unselected patients undergoing hs-cTnT measurement, the hs-cTnT thresholds of greater than 52 and greater than 100 ng/L provide suboptimal performance for identifying high-risk patients. In patients with chest discomfort, an hs-cTnT concentration of greater than 100 ng/L, but not the European Society of Cardiology-recommended threshold of greater than 52 ng/L, provides an acceptable performance but should be used only with other clinical features.

Integration of clinical and hemodynamic parameters in the prediction of long-term survival in patients with pulmonary arterial hypertension.

BACKGROUND: Current management guidelines for pulmonary arterial hypertension (PAH) recommend a treatment choice based primarily on World Health Organization (WHO) functional class. This study was designed to assess how the incorporation of readily obtained clinical and test-based information may significantly improve the prediction of outcomes over functional class alone. METHODS: Clinical and hemodynamic variables were assessed in 484 consecutive patients presenting with WHO group 1 PAH. The primary outcome measure was time to all-cause mortality over 5 years from the index presentation (data available in all). Follow-up was censored at the time of lung or heart/lung transplant in 21 patients or at 5 years. Predictors of mortality were assessed sequentially using Cox models, with the step-wise incorporation of clinical variables, echocardiographic, and catheterization findings. Results were further compared with the REVEAL (Registry to Evaluate Early and Long-term Pulmonary Arterial Hypertension Disease Management) prediction score. RESULTS: Overall median survival was 237 weeks (95% CI, 196-266), corresponding to 1-year, 3-year, and 5-year survival rates of 81.1% (77.0, 84.7), 61.1% (56.5, 65.3), and 47.9% (43.2, 52.4), respectively. The prediction of mortality was improved incrementally by incorporating clinical and echocardiographic measures with a concordance index (c-index) of 0.84 compared with that of 0.60 with functional class alone. The REVEAL prediction score was validated independently in this cohort to predict both 1-year and 5-year mortality. It had a prediction c-index of 0.71. CONCLUSIONS: The integration of routine PAH clinical (predominantly noninvasive) parameters predicts long-term outcome better than functional class and, hence, should be incorporated into medical management decisions.