Utility of C-terminal proendothelin in the early diagnosis and risk stratification of patients with suspected acute myocardial infarction.

BACKGROUND: Endothelial dysfunction plays a major role in cardiovascular diseases, including acute myocardial infarction (AMI). However, its quantification has not been available as a clinical tool. METHODS: In a prospective international multicentre study, we analyzed the diagnostic and prognostic utility of endothelial dysfunction as quantified by C-terminal proendothelin-1 (CT-proET-1) in 658 consecutive patients presenting with suspected AMI. The final diagnosis was adjudicated by 2 independent cardiologists. Patients were followed long-term for mortality. RESULTS: The adjudicated final diagnosis was AMI in 145 patients (22%). The diagnostic performance of CT-proET-1 for AMI was moderate; its area under the receiver operating characteristic (ROC) curve amounted to 0.66 (95% confidence interval [CI], 0.61-0.72; P < 0.001). There was no significant increase in the AUC when CT-proET-1 was added to either cardiac troponin T (cTnT) or high-sensitivity cTnT (hs-cTnT). Seventy four percent of patients who died during the first 24 months (n = 50) were in the fourth quartile of the CT-proET-1 presentation value (>82 pmol/L). The prognostic accuracy of CT-proET-1 regarding mortality was tantamount to that of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and outperformed cTnT and hs-cTnT both in patients with AMI and in patients without acute coronary syndrome. CT-proET-1 at presentation yielded high prognostic accuracy that was similar to that of the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) risk scores. The TIMI risk score could be significantly improved by adding CT-proET-1 (integrated discriminatory improvement [IDI] of 0.074 P = 0.004). CONCLUSIONS: Use of CT-proET-1 improves risk stratification of unselected patients with suspected AMI. CT-proET-1 did not provide additional diagnostic value.

Systolic blood pressure at Emergency Department presentation and 1-year mortality in acute chest pain patients.

BACKGROUND: High blood pressure at rest has been an established risk factor for cardiovascular disease. However the relationship between Systolic Blood Pressure (SBP) and 1-year-mortality among acute chest pain patients presenting to Emergency Department (ED); and effects of preexisting renal insufficiency, hemodynamic stress - as quantified by Brain Natriuretic Peptide (BNP) and chest pain duration, on this relationship is unknown. METHODS: Data was used from APACE (Advantageous Predictors of Acute Coronary Syndrome Evaluation), a prospective observational multicenter study of 1240 ED chest pain patients. SBP at presentation was categorized into quartiles: Q1≤127mmHg; Q2 128-142mmHg; Q3 143-160mmHg; Q4≥161mmHg. RESULTS: 60 deaths occurred during 1-year. One-year-mortality-rate showed lower Hazard Ratios for Q2, Q3 and Q4 vs Q1 (HR [95% CI]; 0.39 (0.19-0.78), 0.34 (0.17-0.70), 0.35 (0.17-0.72); p<0.01 respectively). Cox model adjusted for various demographic and treatment variables showed that participants in Q3 and Q4 had better prognoses than Q1. Patients showed progressively better prognosis from Q2 through Q4 vs Q1 only in patients who presented to ED with for more than 12h of chest pain duration. Patients with renal insufficiency had lower SBP at presentation than others (p=0.001). There was no association between the outcome and interaction variable of SBP quartiles and BNP (p=0.27). CONCLUSION: Acute chest pain patients presenting to ED exhibit an inverse association between SBP at presentation and 1-year-mortality; a relationship which appears stronger in those who present with chest pain of greater than 12h duration.