Cardiac troponin I elevation in acute pulmonary embolism is associated with right ventricular dysfunction

Myoglobin stratifies short-term risk in acute major pulmonary embolism

BACKGROUND

Concentrations of cardiac troponins can be elevated in acute pulmonary embolism (APE) indicating myocardial injury. Although concentration of myoglobin (MYO) increases after myocardial damage, even before detectable rise of cardiac troponin levels occurs, MYO was not evaluated in APE. Therefore, we assessed prevalence and prognostic significance of myoglobin in major APE.

METHODS

We studied 46 patients (30 women, aged 61.9+/-17.8 years) with major APE defined with right ventricular dilatation. On admission serum myoglobin, and cardiac troponin T (cTnT) were measured. Serum MYO concentrations >58 ng/ml for women, and >72 ng/ml for men were considered abnormal. CTnT>0.01 ng/ml was regarded to indicate myocardial injury.

RESULTS

MYO levels exceeding sex specific norms were found in 21/46 (45.7%) of patients, while detectable cTnT was found in 24/46 (52.1%) of patients. Seven patients died during hospitalization. Elevated MYO significantly predicted in-hospital mortality (OR 25, 95% CI 1.3-474.2), while increased cTnT concentration did not affect the survival. Among clinical and echocardiographic variables only older age indicated worse prognosis (OR 1.6, 95% CI 1.06-2.41).

CONCLUSIONS

Myoglobin levels are elevated in serum on admission in almost half of patients with major APE. Elevated myoglobin level, marker of myocardial injury, is a powerful predictor of increased risk of fatal outcome in major pulmonary embolism.

Troponin levels as a guide to treatment of pulmonary embolism

Right ventricular dysfunction in hemodynamically stable patients with acute pulmonary embolism may be a harbinger of adverse outcomes and may potentially result in the early use of thrombolytic therapy. Risk stratification of these patients is an area of recent and intense investigation with a focus on the assessment of right ventricular function after the embolic event. Echocardiography has been used to identify right ventricular dysfunction but is potentially hampered by a number of limitations. With the onset of right ventricular dilation and possible ischemia in acute pulmonary embolism, elevated serum troponins may be an early and reliable marker of right ventricular dysfunction. In acute pulmonary embolism, both right ventricular dysfunction by echocardiogram and elevated troponin levels have been shown to predict an adverse outcome. Therefore, serum troponin levels should help stratify patients with submassive acute pulmonary embolism into a group in which aggressive medical or surgical intervention would be considered.

Detectable serum cardiac troponin T as a marker of poor prognosis among patients with chronic precapillary pulmonary hypertension

BACKGROUND

Right ventricular failure is a leading cause of death in patients with chronic pulmonary hypertension (PH). We checked whether detection of cardiac troponin T (cTnT), a specific marker of myocyte injury, could be useful in prognostic stratification of those patients.

METHODS AND RESULTS

Initial evaluation of 56 clinically stable patients (age 41+/-15 years) with pulmonary arterial (51 patients) or inoperable chronic thromboembolic (5 patients) PH (mean pulmonary arterial pressure 60+/-18 mm Hg) included cTnT test, allowing detection of its serum levels > or =0.01 ng/mL [cTnT(+)]. cTnT was detectable in 8 of 56 (14%) patients (mean+/-SD, 0.034+/-0.022; range, 0.010 to 0.077 ng/mL). Despite similar pulmonary hemodynamics, they had higher heart rate (92+/-15 versus 76+/-14 bpm, P=0.004), lower mixed venous oxygen saturation (50+/-10% versus 57+/-9%, P=0.04), and higher serum N-terminal pro-B-type natriuretic peptide (4528+/-3170 versus 2054+/-2168 pg/mL, P=0.03) and walked less during the 6-minute walk test (298+/-132 versus 396+/-101 m, P=0.02). Cumulative survival estimated by Kaplan-Meier curves was significantly worse at 24 months in cTnT(+) compared with cTnT(-) (29% versus 81%, respectively, log-rank test P=0.001). Multivariate analysis revealed cTnT status (hazard ratio, 4.89; 95% CI, 1.18 to 20.29; P=0.03), 6-minute walk test (hazard ratio, 0.93 for each 10 m; P=0.01), and pulmonary vascular resistance (hazard ratio, 1.13; P=0.01) as independent markers of mortality. All 3 cTnT(+) patients who survived the follow-up period converted to cTnT(-) during treatment.

CONCLUSIONS

Detectable cTnT is a so-far ignored independent marker of increased mortality risk in patients with chronic precapillary PH, supporting the role of progressive myocyte injury in the vicious circle leading to hemodynamic destabilization.

Use of pulse oximetry to predict in-hospital complications in normotensive patients with pulmonary embolism

PURPOSE

A simple method is needed to risk stratify normotensive patients with pulmonary embolism. We studied whether bedside clinical data can predict in-hospital complications from pulmonary embolism.

METHODS

We performed a multicenter derivation phase, followed by validation in a single center. All patients were normotensive; the diagnosis of pulmonary embolism was established by objective imaging. Classification and regression analysis was performed to derive a decision tree from 27 parameters recorded from 207 patients. The validation study was conducted on a separate group of 96 patients to determine the derived criterion's diagnostic accuracy for in-hospital complications (cardiogenic shock, respiratory failure, or death).

RESULTS

Mortality in the derivation phase was 4% (n = 8) at 24 hours and 10% (n = 21) at 30 days. A room-air pulse oximetry reading <95% was the most important predictor of death; mortality was 2% (95% confidence interval [CI]: 0% to 6%) in patients with pulse oximetry >or=95% versus 20% (95% CI: 12% to 29%) with pulse oximetry <95%. In the validation phase, the room-air pulse oximetry was <95% at the time of diagnosis in 9 of 10 patients who developed an in-hospital complication (sensitivity, 90%) and >or=95% in 55 of 86 patients without complications (specificity, 64%).

CONCLUSION

Mortality from pulmonary embolism in normotensive patients is high. A room-air pulse oximetry reading >or=95% at diagnosis is associated with a significantly lower probability of in-hospital complications from pulmonary embolism.

Cardiac troponin T monitoring identifies high-risk group of normotensive patients with acute pulmonary embolism

STUDY OBJECTIVES

Indications for thrombolysis in normotensive patients with pulmonary embolism (PE), based on the presence of right ventricular (RV) overload during transthoracic echocardiography (TTE), are controversial. We checked whether the monitoring of cardiac troponin T (cTnT) might help in risk stratification by detecting patients with RV myocardial injury.

PATIENTS AND DESIGN

We studied 64 normotensive patients (30 women and 34 men) with a mean (+/- SD) age of 61.3 +/- 17 years and PE, who had undergone TTE for the assessment of RV overload. Plasma cTnT levels were measured quantitatively (detection limit, > 0.01 ng/mL) at hospital admission, and subsequently three times at 6-h intervals. Heparin therapy alone was used in 87.5% of patients, while 12.5% of patients received thrombolysis.

RESULTS

cTnT was detected in 50% of patients. All eight in-hospital deaths occurred in the troponin-positive group, however, in one case the results of the first three assays had been negative. Elevated plasma cTnT increased the risk of PE-related death (odds ratio [OR], 21; 95% confidence interval [CI], 1.2 to 389). Increased age and elevated tricuspid regurgitant jet velocity, but not RV diameter/left ventricle diameter ratio, influenced the hospital mortality rate. Increased cTnT level was the only parameter predicting 15 in-hospital clinical adverse events (ie, death, thrombolysis, cardiopulmonary resuscitation, and IV use of catecholamine agents) [OR, 24.1; 95% CI, 2.9 to 200].

CONCLUSIONS

Patients with PE and elevated cTnT levels detected during repetitive assays are at a significant risk of a complicated clinical course and fatal outcome.

Cardiac troponin I in aortic valve disease

BACKGROUND

Plasma cardiac troponin I levels may be higher than normal in conditions other than ischemic heart disease. We aimed at measuring troponin I levels in aortic valve patients, in which increased values for left ventricular dimensions and pressure are frequently found.

METHODS

Plasma levels of troponin I, creatine kinase (CK) and the MB fraction of the same enzyme were measured in a group of 25 clinically stable aortic valve patients. Echocardiographic study was performed in all patients; hemodynamic and coronary angiographic study was performed in 19 patients. Troponin I was also measured in a control population (n=305).

RESULTS

The mean value for troponin I was found to be higher in aortic valve patients (0.07+/-0.02 ng/ml), when compared to controls (0.01+/-0.02 ng/ml; P<0.05). Significant correlations were found between troponin I and both creatine kinase and its MB fraction. When the 25 patients were divided into two groups, with lower (up to 0.04 ng/ml; 12 patients) and higher (0.05 ng/ml or greater; 13 patients) values for troponin I, patients with higher values were found to have greater mean left ventricular wall thickness (9.9+/-0.3 mm, n=11, vs. 12.1+/-0.3 mm, n=13) and pulmonary artery systolic pressures (36.6+/-2.5 mmHg, n=7, vs. 53.7+/-3.4 mmHg, n=9).

CONCLUSIONS

We conclude that slightly raised plasma levels of cardiac troponin I are relatively common in aortic valve patients with no evidence of ischemia. Higher left ventricular wall thickness and pulmonary artery systolic pressure may be related to slightly raised troponin I plasma levels.

Clinical usefulness and prognostic value of elevated cardiac troponin I levels in acute pulmonary embolism

BACKGROUND

Right ventricular myocardial ischemia and injury contribute to right ventricular dysfunction and failure during acute pulmonary embolism. The objective of this study was to evaluate the clinical usefulness of cardiac troponin I (cTnI) in the assessment of right ventricular involvement and short-term prognosis in acute pulmonary embolism

METHODS

Thirty-eight patients with acute pulmonary embolism were included in the study. Clinical characteristics, right ventricular involvement, and clinical outcome were compared in patients with elevated levels of serum cTnI versus patients with normal levels of serum cTnI.

RESULTS

Among the study population (n = 38 patients), 18 patients (47%) had elevated cTnI levels (mean +/- SD 1.6 +/- 0.7 ng/mL, range 0.7-3.7 ng/mL, median, 1.4 ng/mL), and comprised the cTnI-positive group. In the other 20 patients, the serum cTnI levels were normal (< or =0.4 ng/mL), and they comprised the cTnI-negative group. In the cTnI-positive group (n = 18 patients), 12 patients (67%) had right ventricular dilatation/hypokinesia, compared with 3 patients (15%) in the cTnI-negative group (n = 20 patients, P =.004). Right ventricular systolic pressure was significantly higher in the cTnI-positive group (51 +/- 8 mm Hg vs 40 +/- 9 mm Hg, P =.002). Cardiogenic shock developed in a significantly higher number of patients with elevated serum cTnI levels (33% vs 5%, P =.01). In patients with elevated cTnI levels, the odds ratio for development of cardiogenic shock was 8.8 (95% CI 2.5-21).

CONCLUSIONS

Patients with acute pulmonary embolism with elevated serum cTnI levels are at a higher risk for the development of right ventricular dysfunction and cardiogenic shock. Serum cTnI has a role in risk stratification and short-term prognostication in patients with acute pulmonary embolism.

Cardiac troponin I in patients with severe exacerbation of chronic obstructive pulmonary disease

OBJECTIVES

Co-morbid conditions including risk factors for cardiovascular diseases and left ventricular dysfunction are common in patients with chronic obstructive pulmonary disease (COPD). This study assessed the incidence of cardiac troponin I (cTnI) elevation, a specific marker for cardiac injury, and its prognostic significance during severe exacerbation of COPD.

DESIGN

Prospective cohort study.

SETTING

Two intensive care units.

PARTICIPANTS

Seventy-one consecutive patients admitted for severe exacerbation of COPD.

INTERVENTION

None.

MEASUREMENTS AND RESULTS

Cardiac troponin I was assayed in blood samples obtained on admission and 24 h later (Stratus II immunoassay analyser, Dade International). Levels above 0.5 ng/ml were considered positive. The following data were recorded prospectively: clinical symptoms, co-morbidities, cause of the exacerbation, diagnostic procedures and treatment, general severity score (SAPS II) and in-hospital outcome. CTnI was positive in 18% of patients (95% confidence interval (CI(95)), 11-29%), with a median value at 1.00 ng/ml; CI(95 )(0.60-1.70). Eighteen patients died in the hospital (25%; CI(95), 17-37%). Only cTnI (adjusted odds ratio (ORa), 6.52; CI(95),1.23-34.47) and SAPS II 24 h after admission (ORa, 1.07; CI(95), 1.01-1.13) were independent predictors of in-hospital mortality.

CONCLUSION

Elevated cTnI is a strong and independent predictor of in-hospital death in patients admitted for acutely exacerbated COPD.

Low pro-brain natriuretic peptide levels predict benign clinical outcome in acute pulmonary embolism

BACKGROUND

The role of pro-brain natriuretic peptide (proBNP) for the prediction of clinical outcome has not been examined in patients with acute pulmonary embolism (PE).

METHODS AND RESULTS

ProBNP levels were measured in 73 patients with acute PE within 4 hours of admission. Adverse clinical outcome was defined as in-hospital death or the need for at least 1 of the following: cardiopulmonary resuscitation, mechanical ventilation, pressors, thrombolysis, catheter fragmentation, or surgical embolectomy. In the 53 patients with a benign clinical outcome, proBNP (median 121, range 16 to 34 802 pg/mL) was lower than in 20 patients with adverse clinical outcome (median 4250, range 92 to 49 607 pg/mL; P<0.0001). The negative predictive value of proBNP levels <500 pg/mL to predict adverse clinical outcome was 97% (95% confidence interval 84 to 99). ProBNP remained an independent predictor for adverse clinical outcome (odds ratio 14.6; 95% confidence interval 1.5 to 139.0; P=0.02) after adjusting for severity of PE (submassive/massive), troponin T levels >0.01 ng/mL, age >70 years, gender, and history of congestive heart failure.

CONCLUSIONS

Low proBNP levels predict an uneventful hospital course in patients with acute PE. A proBNP level <500 pg/mL identifies patients who will be potential candidates for an abbreviated hospital length of stay or care on a completely outpatient basis.

Local and systemic thrombolytic therapy for acute venous thromboembolism

Thrombolytic therapy unquestionably leads to more rapid and complete clot lysis with a significantly higher risk of bleeding when compared with anticoagulation. The most definite indication for thrombolytic therapy in patients with VTE is massive PE associated with hemodynamic instability. Other potential indications, although not widely accepted or proven, include PE-related respiratory failure with severe hypoxemia and massive iliofemoral thrombosis with the risk of phlegmasia cerulea dolens. Routine use of thrombolytic therapy in all other cases of PE and DVT cannot be justified. Future research using randomized controlled studies should focus on the following key questions: Do hemodynamically stable patients with PE and right ventricular dysfunction benefit from thrombolysis, and, if so, is there a subset of patients within this group who are most likely to benefit? Does thrombolytic therapy improve long-term outcomes of DVT with a favorable risk-to-benefit ratio, and, if so, which patients are most likely to benefit long-term? What is the precise role of catheter-directed thrombolysis in the treatment of VTE, particularly the use of a low-dose thrombolytic agent in conjunction with mechanical clot disruption to minimize bleeding in patients at high risk? Until these questions are answered, clinicians must approach decision-making regarding the use of thrombolytic therapy in PE and DVT with careful consideration of the potential risks and benefits for the patient within the framework of currently available data.

Positive predictive value of a point-of-care testing strategy on first-draw specimens for the emergency department-based detection of acute coronary syndromes

CONTEXT

The rapid and accurate diagnosis of the etiology of chest pain is of central importance in the triage of patients presenting to emergency departments. The "first-draw" sensitivity of serum cardiac markers is known to be low on initial presentation; however, less is understood regarding the predictive value of a positive test in this situation.

OBJECTIVE

To determine the ability of a critical pathway combining medical history and physical examination, electrocardiographic findings, point-of-care testing, and central laboratory data to accurately predict the presence of acute coronary ischemia.

METHODS

We investigated the positive predictive value of a testing algorithm for first-draw specimens in clinical practice, combining a qualitative, point-of-care, triple-screen testing panel for cardiac markers, including myoglobin, creatine kinase-MB, and cardiac troponin I, with confirmation of the rapid assay in the central hospital laboratory by quantitative assays for creatine kinase-MB and cardiac troponin T.

RESULTS

While a positive result on any of the individual cardiac markers of the point-of-care test had a positive predictive value for the acute coronary syndrome of only 36% (creatine kinase-MB, 41%; myoglobin, 36%; and troponin I, 65%), the positive predictive value for the diagnosis of acute coronary syndrome increased to 76% if all 3 point-of-care markers were simultaneously positive. The positive predictive value for acute coronary syndrome for a positive confirmatory result in the hospital laboratory for either creatine kinase-MB or cardiac troponin T was 61%. Among those patients with a positive marker on both the point-of-care test and the laboratory test, a careful retrospective review of the clinical history (with exclusion of patients with nonischemic cardiac pathologies and renal insufficiency) increased the positive predictive value of this algorithm to 98%.

CONCLUSIONS

Our data suggest that qualitative, point-of-care, triple-screen cardiac marker testing of patients with chest pain at initial presentation may exhibit relatively low positive predictive values. Positive predictive value can be significantly improved by rapid confirmation in the hospital laboratory and careful review of clinical findings.

Atrial septal defect and myocardial infarct

The etiology for an acute myocardial infarction with normal coronary arteriography should rule in and rule out the presence of an atrial septal defect. Acute increases in left to right shunting with an atrial septal defect may lead to episodes of myocardial necrosis and right ventricular dysfunction. This case report describes such a scenario.

Causes of elevated troponin I with a normal coronary angiogram

BACKGROUND

The new definition of myocardial infarction (MI) emphasizes the pre-eminent role of troponin for diagnosis. Troponin rise indicates myocardial injury, but is not synonymous with infarction or ischaemia.

AIMS

To review the precipitating event for troponin elevation in patients with angiographically normal coronary arteries, in a district general hospital.

METHODS

Consecutive patients with elevated troponin I (TnI) who underwent angiography for suspected coronary disease were included in the present study if they had normal or mild disease (<50% diameter loss without complex features or thrombus). Precipitating event for TnI elevation was assigned on the totality of clinical evidence.

RESULTS

Twenty-one patients qualified, with an average age of 50 years (range 33-73). Sixty-two per cent of participants were female. Troponin release was attributed to tachycardia in six patients, only two of whom had haemodynamic compromise. Physical exertion was the precipitating factor in two patients; pericarditis in two patients; and severe congestive heart failure in one patient. Ten of 21 patients had no identifiable cause for a rise in TnI concentration. Five of 21 patients had left-ventricular wall motion abnormalities. There were no deaths or MI at 41 +/- 24 weeks follow up.

CONCLUSION

Troponin is a sensitive marker of myocardial injury and may rise following apparently minor insults. A rise in TnI concentration may have a cause other than acute coronary syndrome and may occur without significant angiographic coronary artery disease.

Importance of cardiac troponins I and T in risk stratification of patients with acute pulmonary embolism

BACKGROUND

Assessment of risk and appropriate management of patients with acute pulmonary embolism (PE) remains a challenge. Cardiac troponins I (cTnI) and T (cTnT) are reliable indicators of myocardial injury and may be associated with right ventricular dysfunction in PE.

METHODS AND RESULTS

The present prospective study included 106 consecutive patients with confirmed acute PE. cTnI was elevated (> or =0.07 ng/mL) in 43 patients (41%), and cTnT (> or =0.04 ng/mL) was elevated in 39 (37%). Elevation of cTnI or cTnT was significantly associated with echocardiographically detected right ventricular dysfunction (P=0.001 and P<0.05, respectively). Moreover, a significant correlation was found between elevation of cTnI or cTnT and the two major end points overall mortality and complicated in-hospital course. The negative predictive value of cardiac troponins for major clinical events was 92% to 93%. Importantly, there was obvious escalation of in-hospital mortality, the rate of complications, and the incidence of recurrent PE, when patients with high troponin concentrations (cTnI >1.5; cTnT >0.1 ng/mL) were compared with those with only moderately elevated levels (cTnI, 0.07 to 1.5; cTnT, 0.04 to 0.1 ng/mL). Logistic regression analysis confirmed that the mortality risk (OR) was significantly elevated only in patients with high cTnI (P=0.019) or cTnT (P=0.038) levels. Furthermore, the risk of a complicated in-hospital course was almost 5 times higher (15.47 versus 3.16) in the high-cTnI group compared with patients with moderate cTnI elevation.

CONCLUSIONS

Our results indicate that cTnI and cTnT may be a novel, particularly useful tool for optimizing the management strategy in patients with acute PE.

Diagnosis of myocardial injury by biochemical markers: problems and promises

The role of biochemical markers in the diagnosis of acute coronary syndromes has increased considerably in the past decade. The World Health Organization previously defined acute myocardial infarction as a combination of at least 2 of 3 components: symptoms consistent with acute myocardial infarction, electrocardiogram changes diagnostic of acute myocardial infarction, and an enzyme pattern with classic rise and fall. Measurement of creatine kinase and its MB fraction by various assays was the gold standard for the diagnosis. Troponins are more specific and sensitive markers for myocardial injury, and their increasing utilization has resulted in a broadening of the definition of acute myocardial infarction to incorporate high-risk acute coronary syndromes. Previously, traditional enzyme evaluation left patients with small amounts of cellular death undiagnosed; these patients were categorized as having unstable angina or, worse, noncardiac chest pain. Newer markers now identify these patients as a subgroup at high risk for cardiac death or cardiac events. Newer therapeutic interventions and a more invasive strategy have been shown to improve outcomes in this high-risk subgroup. Increased specificity has also reduced the number of patients who undergo extensive, expensive, and invasive evaluations for noncardiac syndromes due to false elevations of traditional markers. This article comprehensively reviews the evolution of biochemical markers for the diagnosis of acute myocardial infarction, addressing their promise for improving delivery of care and outcomes and their technical and diagnostic pitfalls.

Diagnostic utility of cardiac troponin-I levels in patients with suspected pulmonary embolism

Although positive troponin-I (TnI) assays have been reported in patients with pulmonary embolism (PE), TnI levels in patients with suspected PE have not been evaluated systematically. The purpose of this study was to evaluate the diagnostic utility of TnI measurements in patients with suspected PE. Consecutive patients with suspected PE were identified in whom nuclear ventilation/perfusion (V/Q) scans were performed and TnI levels were measured. TnI levels in patients with and without positive V/Q scans were compared by use of t tests. After categorizing TnI levels as positive (TnI-pos, > or = 0.40 ng/mL) or negative, chi-square tests were used to relate these values to V/Q scan results. Separate comparisons were made for subjects with high-probability V/Q scans (V/Q-high, > or = 90% likelihood of PE) and intermediate- or high-probability V/Q scans (V/Q-pos, > or = 50% likelihood of PE). The mean TnI level in the 10 subjects with V/Q-high scans was 0.39 +/-0.79 ng/mL. The mean TnI level in the 81 subjects without V/Q-high scans was 0.36 +/-0.66 ng/mL (p=0.89). TnI levels did not differ between the 22 V/Q-pos subjects and the 69 subjects with negative V/Q scans (p = 0.86). A positive TnI in the setting of V/Q-pos had a sensitivity of 32%, specificity of 71%, positive predictive value of 26%, and a negative predictive value = 77% (chi-square = 0.06, p = 0.80). Elevated TnI levels are not associated with positive V/Q scans. The TnI assay is not a useful test in patients suspected of having PE, unless used to exclude myocardial ischemia or infarction.

Thresholds for the electrocardiographic change range of biochemical markers of acute myocardial infarction (GUSTO-IIa data)

The definition of acute myocardial infarction (AMI) is increasingly dependent on levels of biochemical markers, including troponin. We aimed to determine the levels of biochemical markers associated with definite evolutionary electrocardiographic (ECG) changes in patients with ST-segment elevation myocardial infarction. By examining the database of 855 patients from the troponin substudy of GUSTO-IIa, we selected patients with ST-segment elevation at baseline, evidence of evolution of the QRS, T, and ST-segment waveforms on the predischarge electrocardiogram, and 3 measurements of > or =1 of the following: creatine kinase (CK)-MB, troponin T, or troponin I. We identified 222 patients with evolutionary ECG changes. The median QRS score for this population was 5 points; the fifth percentile was 1. For patients with 3 CK-MB measurements, the fifth percentile as a multiple of the upper limit of normal was 2.1 (upper limit of normal 7.0 ng/ml). For patients with troponin T measurements, the fifth percentile as a multiple of the upper limit of normal was 11.0 (upper limit of normal 0.1 ng/ml). For patients with troponin I measurements, the fifth percentile as a multiple of the upper limit of normal was 3.8 (upper limit of normal 1.5 ng/ml). This study revealed that 95% of the patients with definite ECG evidence of AMI had a more than twofold increase in CK-MB and more than a 3- to 11-fold increase in troponin.

Predicting cancer therapy-induced cardiotoxicity: the role of troponins and other markers

Several anticancer drugs have been associated with cardiac toxicity, especially the anthracyclines and trastuzumab. The pathogenesis of anthracycline-associated toxicity has been well described, whereas the mechanism of trastuzumab-associated toxicity is unknown. Although routine cardiac imaging studies (e.g. echocardiogram or multiple gated acquisition scans) may identify subclinical evidence of myocardial dysfunction, available data do not support their routine use for monitoring asymptomatic patients undergoing cancer therapy. Other modalities such as nuclear medicine scintigraphy with indium-111-antimyosin antibody and endomyocardial biopsy have been shown to be useful in identifying early cardiac damage, but their routine use is limited by practical considerations such as feasibility and cost. Consequently, there is significant interest in developing simple and reproducible methods for identifying patients at risk for treatment-induced myocardial damage. Available data suggest that circulating markers such as troponins and natriuretic peptides could potentially be useful for this purpose. Measurement of plasma troponin levels are commonly used in clinical practice in order to provide diagnostic and prognostic information in patients with myocardial ischaemia. Elevated levels may likewise correlate with anthracycline-induced cardiac damage, although plasma levels are only minimally elevated (well below that associated with ischaemia), and elevations may persist for weeks or months after anthracycline exposure. Clinical trials are currently evaluating the role of these markers in predicting both early and late, clinical and subclinical damage associated with anthracyclines and trastuzumab.

Risk factors for adverse short-term outcome in patients with pulmonary embolism

Pulmonary embolism (PE) is a common and potentially fatal disease. Death usually occurs before hospital admission or in the initial in-hospital phase. A number of clinical and instrumental findings have been associated with a high risk of adverse short-term clinical outcomes in patients with PE. Advanced age, concomitant cardiopulmonary disease, and haemodynamic instability, as well as large perfusion defects at lung scanning and acute right heart dysfunction as assessed by echocardiography, are associated with adverse in-hospital outcome. Elevated serum levels of troponin I have been recently demonstrated to be associated with severe right ventricular dysfunction and adverse in-hospital outcome in patients with PE. Early recurrence of PE is associated with a high mortality rate. Right heart dysfunction, as assessed by echocardiography and an acute fall in platelet count, have been suggested as risk factors for recurrence of PE. A reduction in mortality in the subgroup of patients with a poor prognosis might be achieved by using more aggressive treatments such as thrombolysis and surgical or interventional procedures. However, such treatments are invariably associated with bleeding and other procedural complications.

Prognosis in pulmonary embolism

Acute pulmonary embolism has a wide prognostic spectrum, ranging from sudden death within minutes of a thromboembolic episode to a benign treatable condition associated with a stable clinical course and no long-term sequelae. In patients who survive an initial thromboembolic episode and receive antithrombotic therapy, the clinical course can be complicated by recurrent nonfatal venous thromboembolism, fatal pulmonary embolism, the postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension. Identifying which patients are at increased risk of experiencing these sequelae is important in decision making relating to the aggressiveness of initial antithrombotic therapy, the duration of antithrombotic therapy, and the frequency of clinical surveillance. In addition, this information may be helpful to clinicians in discussing disease prognosis with patients. The objectives of this review are to provide reasonable estimates of the risks of recurrent nonfatal venous thromboembolism, fatal pulmonary embolism, the postthrombotic syndrome, and chronic thromboembolic pulmonary hypertension in patients with treated pulmonary embolism, and to identify risk factors for these sequelae.