An Hypothesis: Disproportion Between Cardiac Troponin and B-Type Natriuretic Peptide Levels-A High Risk and Poor Prognostic Biomarker in Patients With Fulminant Myocarditis?

In our clinical practice, we recently found some patients with severe fulminant myocarditis (FM) who showed persistently elevated cardiac troponin (cTn) levels and "seemingly normal" B-type natriuretic peptide (BNP) level, and who subsequently progressed to poor outcomes. Indeed, this sounds contrary to conventional wisdom, but it is not an accidental phenomenon. Fulminant myocarditis is a rapidly progressive disease associated with high mortality. Recent studies have shown that patients with FM are significantly more likely to require heart transplantation than those without FM. Prompt diagnosis of FM and the institution of advanced cardiac life support will save more lives. Cardiac troponin and BNP are widely used diagnostic markers. Cardiac troponin is a specific marker of cardiac injury and its level correlates with the severity of cardiac injury. However, plasma BNP has a dual identity; it is not only a marker of cardiac pressure/volume overload, but it is also a cardioprotective factor that provides effective neurohormonal compensation to maintain homeostasis. Similar to fulminant hepatitis (characterised by diffuse inflammation and massive parenchymal cell necrosis) sometimes showing disproportion between transaminase level and bilirubin level, the disproportion between cTn and BNP levels in FM seems to be consistent with its severe histopathological changes, including diffuse infiltration of the myocardium by inflammatory cells, as well as severe cardiomyocyte injury and necrosis. Moreover, in previous studies, a lower BNP level was found to be an adverse prognostic marker in end-stage heart failure. All these findings indicate that in patients with FM with a persistently high cTn level and ominous clinical presentation, a "seemingly normal" BNP level is not a friendly signal. We hypothesise that the combination of a persistently elevated cTn level and low BNP level in patients with FM indicates worse myocardial injury and poor prognosis.

Implications of elevated cardiac troponin in patients presenting with acute pulmonary embolism: an observational study.

BACKGROUND: To evaluate the implications of elevated cardiac troponin (cTn) in patients presenting with pulmonary embolism (PE). METHODS: We conducted a retrospective analysis for patients with PE between 2011 and 2015 with an average of 3 years follow-up. Patients were categorized into two groups based on the cTn status on admission (negative vs. positive) and RV/LV ratio (≤1.2 vs. >1.2). PE diagnosis was made by computed tomography pulmonary angiography (CTPA) examinations. RESULTS: Among 220 patients with PE, 52.7% had positive cTn and 31.7% had RV dysfunction. Protein S and C deficiency were significantly higher in patients with negative cTn. Patients with positive cTn were more likely to have high-risk simplified pulmonary embolism severity index (sPESI), RV dilation, RV/LV ratio >1.2, severe inferior vena cava reflux and high Qanadli score (QS >18 points). Thrombolytic therapy was used in 15 patients; 9 (60%) of them had elevated troponin. Combined cTn and sPESI had higher sensitivity, negative predictive value and negative likelihood ratio to predict in-hospital mortality. Overall 30-day and 3 years morality were 10.0% and 22.3%; that were significantly higher in patients with positive troponin. Cox regression analysis showed that mortality increased 2.5 times with positive cTn after adjusting for age, sex, and RV dysfunction (adjusted HR 2.5; 95% CI: 1.25-5.01), P=0.009. CONCLUSIONS: Elevated cTn is independent predictor of short and long-term mortality. The predictive power of cTn increases when combined with the clinical probability score. Further, larger prospective studies are needed to confirm the findings of the present study.

Point-of-Care Diagnosis of Acute Myocardial Infarction in Central Vietnam: International Exchange, Needs Assessment, and Spatial Care Paths.

OBJECTIVES: Objectives were to (a) advance point-of-care (POC) education, international exchange, and culture; (b) report needs assessment survey results from Thua Thien Hue Province, Central Vietnam; (c) determine diagnostic capabilities in regional health care districts of the small-world network of Hue University Medical Center; and (d) recommend Spatial Care Paths that accelerate the care of acute myocardial infarction (AMI) patients. METHODS: We organized progressively focused, intensive, and interactive lectures, workshops, and investigative teamwork over a 2-year period. We surveyed hospital staff in person to determine the status of diagnostic testing at 15 hospitals in 7 districts. Questions focused on cardiac rapid response, prediabetes/diabetes, infectious diseases, and other serious challenges, including epidemic preparedness. RESULTS: Educational exchange revealed a nationwide shortage of POC coordinators. Throughout the province, ambulances transfer patients primarily between hospitals, rarely picking up from homes. No helicopter rescue was available. Ambulance travel times from distant sites to referral hospitals were excessive, longer in costal and mountainous areas. Most hospitals (92.3%) used electrocardiogram and creatine phosphokinase-MB isoenzyme to diagnose AMI. Cardiac troponin I/T testing was performed only at large referral hospitals. CONCLUSIONS: Central Vietnam must improve rapid diagnosis and treatment of AMI patients. Early upstream POC cardiac troponin testing on Spatial Care Paths will expedite transfers directly to hospitals capable of intervening, improving outcomes following coronary occlusion. Point-of-care coordinator certification and financial support will enhance standards of care cost-effectively. Training young physicians pivots on high-value evidence-based learning when POC cardiac troponin T/cardiac troponin I biomarkers are in place for rapid decision making, especially in emergency rooms.