Prevalence of increased cardiac troponin I levels in patients with and without acute pulmonary embolism and relation of increased cardiac troponin I levels with in-hospital mortality in patients with acute pulmonary embolism

Cardiac troponin I levels were increased in 24 of 147 patients (16%) with documented acute pulmonary embolism and in 20 of 594 patients (3%) without pulmonary embolism (p <0.001). In patients with acute pulmonary embolisms, 8 of 24 (33%) with increased cardiac troponin I levels and 9 of 123 (7%) with normal cardiac troponin I levels died during hospitalization (p <0.001).     

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 (≤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.     

Normal D-dimer levels in emergency department patients suspected of acute pulmonary embolism

OBJECTIVES: We sought to determine:1) whether normal D-dimer enzyme-linked immunosorbent assay (ELISA) assays predicted the absence of pulmonary embolism (PE) in the high-volume emergency department (ED) of the Brigham and Women's Hospital, and 2) whether ED physicians accepted normal D-dimer levels as confirmation of no PE without further diagnostic testing such as lung scanning, chest computed tomography (CT) scanning, or pulmonary angiography. BACKGROUND: Although the plasma D-dimer ELISA is a sensitive screening test for excluding acute PE, this laboratory marker has not been widely integrated into clinical algorithms such as creatine kinase-MB fraction or troponin testing for acute myocardial infarction. METHODS: We mandated that ED physicians order D-dimer ELISA tests on all patients suspected of acute PE. We reviewed the clinical record of each ED patient initially evaluated for suspected PE during the year 2000. We determined whether additional imaging tests for PE were obtained and whether the final diagnosis was PE. RESULTS: Of 1,106 D-dimer assays, 559 were elevated and 547 were normal. Only 2 of 547 had PE despite a normal D-dimer. The sensitivity of the D-dimer ELISA for acute PE was 96.4% (95% confidence interval [CI]: 87.5% to 99.6%), and the negative predictive value was 99.6% (95% CI: 98.7% to >99.9%). Nevertheless, 24% of patients with normal D-dimers had additional imaging tests for PE. CONCLUSIONS: The D-dimer ELISA has a high negative predictive value for excluding PE. By paying more attention to normal D-dimer results, fewer chest CT scans and lung scans will be required, and improvements may be realized in diagnostic efficiency and cost reduction.     

Correlated expression of D-dimer concentrations with thrombotic burden in acute pulmonary embolism.

Thrombotic burden might have an influence upon the concentration of D-dimer in patients with acute pulmonary embolism. Patients with small pulmonary embolisms may thus present with relatively low concentrations of D-dimer. The objective of this study was to assess the correlation of the concentrations of D-dimer with the pulmonary artery occlusion score (PAOS) in a cohort of patients with acute pulmonary embolism. We have presently studied the correlation between the concentrations of D-dimer and the PAOS in a group of 75 patients who presented to the Department of Emergency Medicine with a clinical picture suggestive for acute pulmonary embolism and whose pulmonary computerized tomography (CT) angiography was positive for pulmonary embolism. A significant (P < 0.001) correlation (r = 0.42) was noted between the concentration of D-dimer and the PAOS in this group of 75 patients with acute pulmonary embolism. We further divided the cohort into those patients who had a score below the median of 18 (n = 37) and those who had a score above the median (n = 38), the corresponding mean concentrations of D-dimer being 364 and 814 ng/ml, respectively, in contrast to a mean concentration of 285 ng/ml that was observed in the group of controls (n = 73). In addition, from the receiver-operated characteristic (ROC) curves that were produced for the purpose of differentiating between the presence or absence of pulmonary embolism, for those who had a low score it was not possible to differentiate between those who had or did not have a pulmonary embolism [area under the curve 0.595 as opposed to 0.835 (P < 0.001) for the group with the high score]. Patients with acute small pulmonary embolism might present with relatively low concentrations of D-dimer. These findings might have implications regarding the diagnostic yield of D-dimer in patients who are suspected of having an acute pulmonary embolism.     

NT-proBNP levels on admission predicts pulmonary hypertension persistence in patients with acute pulmonary embolism

BackgroundChronic thromboembolic pulmonary hypertension (CTEPH) is a rare, but due to its unfavorable prognosis, feared complication of thromboembolic disease. We assessed the incidence and risk factors for pulmonary hypertension (PH) in a cohort of consecutive patients admitted with pulmonary embolism to the tertiary University Hospital.MethodsIn our cohort of 120 consecutive patients with proved pulmonary embolism (PE) we studied the course of biochemical and echocardiographic parameters with regard to risk factors predicting pulmonary hypertension at the end of hospitalization.ResultsEchocardiographic signs of pulmonary hypertension were present at the time of discharge in more than one half (50.8%) of patients admitted with pulmonary embolism. Predictors of persisting pulmonary hypertension were initial pulmonary hypertension, high initial NT-proBNP levels and age.ConclusionResidual pulmonary hypertension at discharge was present in 50.8% cases, at this time there was a strong relationship between PH and elevated NT-proBNP on admission. The patients will be followed-up and possible development of CTPEH will be evaluated at 6, 12 and 24-month period.     

Normal D-dimer levels in patients with pulmonary embolism.

BACKGROUND: Pulmonary embolism (PE) is frequently evaluated in acute care settings. Despite this, the clinical diagnosis of PE is difficult. Results of ventilation-perfusion (V/Q) scans may be inconclusive, and pulmonary angiograms (PAGs) are cumbersome, involve risk, and are often unavailable. Using PAG as the standard criterion, we evaluated the relationship between PE, V/Q scans, and semiquantitative latex agglutination (LA) D-dimer levels. METHODS: Ninety-eight patients who underwent V/Q scanning for suspected PE were enrolled; based on the results of the scans, the patients were scheduled for PAG. Blood samples were drawn for LA D-dimer assays during the PAGs at Saint Joseph Hospital, Denver, Colo, from January 1, 1996, to February 1, 1997. A detailed medical record review was performed for all enrollees. RESULTS: The mean+/-SEM patient age was 56.6+/-1.9 years; 52 (53%) were men, 13 (13%) had cancer, 23 (23%) had undergone surgery within 30 days of their PAG, and 13 (13%) were receiving warfarin sodium. There were no differences in warfarin therapy, hypercoaguable state, or cancer prevalence between patients with negative and positive PAGs (P = .53). Ventilation-perfusion scan results were available for all study patients. Eight (27%) of 30 patients who had positive angiogram results had LA D-dimer levels less than 250 ng/mL. Patients with positive PAGs (n = 30) had the following V/Q scan results: normal, 0; low probability, 7; intermediate or indeterminate probability, 22; and high probability, 1. In patients with low-probability V/Q scan results (n = 34), a positive D-dimer result for PE (>250 ng/mL) had a sensitivity of 71.4% (95% confidence interval, 0.29-0.97) and a negative predictive value of 87.5% (95% confidence interval, 0.62-0.98). We found a significant difference in D-dimer levels in patients with an abnormal angiogram result (mean, 750 ng/mL) compared with patients with a normal angiogram result (mean, 250 ng/mL) (P= .01, chi2 test). CONCLUSIONS: Eight patients had normal D-dimer levels with angiographic evidence of PE. Algorithms in acute care settings have been proposed; they exclude PE with normal D-dimer levels using the enzyme-linked immunosorbent assay technique. These cannot be extrapolated to the more widely used LA assays. A normal LA D-dimer level alone or with V/Q scan results is not recommended to preclude the treatment of PE.     

Abnormal troponin I levels after supraventricular tachycardia

Elevated troponin I in the absence of angiographically visible coronary lesions is seen in up to 10-15% of those undergoing angiography for suspected coronary artery disease. Serum troponin-I is a sensitive indicator of myocardial damage but abnormal troponin I levels have been also reported without acute coronary syndrome and without cardiac damage. Cardiac troponin I is released from myocytes in both reversible and irreversible myocardial injury. The changes in myocyte membrane permeability resulting from the injury could be enough for the release of cardiac troponins from the free cytosolic pool of myocytes without structural damage. It has been reported that the presence of tachycardia sufficient to warrant hospital admission also can raise troponin. We present a case of troponin I positive in a 49-year-old Italian woman admitted to the hospital with supraventricular tachycardia. Also this case focuses attention on the importance of a correct evaluation of abnormal troponin I levels.     

High D-dimer levels increase the likelihood of pulmonary embolism

Objective. To determine the utility of high quantitative D-dimer levels in the diagnosis of pulmonary embolism. Methods. D-dimer testing was performed in consecutive patients with suspected pulmonary embolism. We included patients with suspected pulmonary embolism with a high risk for venous thromboembolism, i.e. hospitalized patients, patients older than 80 years, with malignancy or previous surgery. Presence of pulmonary embolism was based on a diagnostic management strategy using a clinical decision rule (CDR), D-dimer testing and computed tomography. Results. A total of 1515 patients were included with an overall pulmonary embolism prevalence of 21%. The pulmonary embolism prevalence was strongly associated with the height of the D-dimer level, and increased fourfold with D-dimer levels greater than 4000 ng mL(-1) compared to levels between 500 and 1000 ng mL(-1). Patients with D-dimer levels higher than 2000 ng mL(-1) and an unlikely CDR had a pulmonary embolism prevalence of 36%. This prevalence is comparable to the pulmonary embolism likely CDR group. When D-dimer levels were above 4000 ng mL(-1), the observed pulmonary embolism prevalence was very high, independent of CDR score. Conclusion. Strongly elevated D-dimer levels substantially increase the likelihood of pulmonary embolism. Whether this should translate into more intensive diagnostic and therapeutic measures in patients with high D-dimer levels irrespective of CDR remains to be studied.     

Prognostic role of right ventricular dilatation and troponin I elevation in acute pulmonary embolism

Acute pulmonary embolism continues to cause significant morbidity and mortality despite advances in diagnosis and treatment. This retrospective analysis aimed to determine whether the combination of elevated troponin I and right ventricular dilatation (RVD) could provide a more powerful predictor for risk evaluation. The study data comprised records of 110 patients with either high-probability ventilation/perfusion lung scan or positive spiral computed tomography. All cause 100-day mortality was 18.2%. The hypotension and RVD variables significantly influenced 100-day mortality. For the combination of RVD and raised troponin I, the 100-day mortality rate was 31%. Notably, the group with elevated troponin I and no RVD had a 100-day mortality rate of only 3.7%. The combination of RVD and elevated troponin had a positive predictive value of 31% and a negative predictive value of 88% for 100-day mortality. Compared with existing reports, conflicting conclusions for the individual prognostic role of elevated troponin I, cancer, and heart failure were obtained. These conflicting conclusions most likely resulted from inappropriate cut-off troponin I values and the modest sample size. In conclusion, the combination of elevated troponin and RVD was able to identify a subset of patients most likely to benefit from aggressive therapy.     

D-二聚体在急性肺栓塞快速临床诊断中的价值

目的探讨血浆D-二聚体、下肢深静脉血栓在急性肺栓塞(acute pulmonary embolism,APE)快速临床诊断中的价值。方法回顾性分析疑诊为APE的178例患者的计算机(X线)断层摄影扫描肺血管造影或右心导管选择性肺动脉造影的临床资料、血浆D-二聚体浓度及下肢深静脉彩色多普勒检查结果。结果 APE患者血浆D-二聚体浓度阳性者59例(96.72%,59/61),非APE患者阳性32例(27.4%,32/117),两者比较差异有统计学意义(P0.05)。APE患者经彩色多普勒超声检查发现下肢深静脉血栓形成(deep venous thrombosis,DVT)50例(82.0%,50/61),非APE患者DVT 6例(5.0%,6/117),两组比较差异有统计学意义(P0.05)。48例(78.7%,48/61)APE患者血浆D-二聚体浓度阳性合并DVT,两项指标同为阳性时诊断APE的特异性99.1%,阳性预测值98.0%。血浆D-二聚体浓度阳性诊断APE的敏感性96.7%,特异性72.6%,阳性似然比3.54,阴性似然比0.04,阳性预测值64.8%,阴性预测值97.7%。结论血浆D-二聚体、下肢深静脉彩色多普勒检查值得作为常规方法为快速诊断及治疗APE提供依据。     

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

OBJECTIVES: The purpose of this study was to evaluate the prevalence and diagnostic utility of cardiac troponin I to identify patients with right ventricular (RV) dysfunction in pulmonary embolism. BACKGROUND: Right ventricular overload resulting from elevated pulmonary resistance is a common finding in major pulmonary embolism. However, biochemical markers to assess the degree of RV dysfunction have not been evaluated so far. METHODS: In this prospective, double-blind study we included 36 study patients diagnosed as having acute pulmonary embolism. RESULTS: Among the whole study population, 14 patients (39%) had positive troponin I tests. Ten of 16 patients (62.5%) with RV dilatation had increased serum troponin I levels, while only 4 of 14 patients (28.6%) with elevated troponin I values had a normal RV diameter as assessed by echocardiography, indicating that positive troponin I tests were significantly associated with RV dilatation (p = 0.009). Patients with positive troponin I tests had significantly more segmental defects in ventilation/perfusion lung scans than patients with normal serum troponin I (p = 0.0002). CONCLUSIONS: Our data demonstrate that more than one-third of patients clinically diagnosed as having pulmonary embolism presented with elevated serum troponin I concentrations. Troponin I tests helped to identify patients with RV dilatation who had significantly more segmental defects in lung scans. Thus, troponin I assays are useful to detect minor myocardial damage in pulmonary embolism.     

心电图与D-二聚体在急性肺栓塞患者的诊断价值

目的探讨心电图与D-二聚体在急性肺栓塞患者的诊断价值。方法选择在我院接受诊治的经肺动脉血管造影检查确诊为急性肺栓塞患者58例作为研究对象,另外选取同期在我院治疗的经X线及细菌学检查确诊为慢性支气管炎患者53例作为对照组,所有患者均接受心电图、D-二聚体诊断,探讨心电图、D-二聚体对急性肺栓塞患者诊断价值。结果心电图检测对急性肺栓塞患者检测阳性率为93.10%,显著高于对慢性支气管炎检测阳性率(P0.05);D-二聚体检测对急性肺栓塞患者检测阳性率为89.66%,显著高于对慢性支气管炎检测阳性率(P0.05)。结论心电图与D-二聚体在急性肺栓塞诊断中均具有重要的诊断价值。     

Cardiac troponin I release in acute pulmonary embolism in relation to the duration of symptoms

PURPOSE: To evaluate the release of cardiac troponin I in normotensive patients with acute pulmonary embolism in relation to the duration of symptoms. METHODS: Fifty-seven normotensive patients with acute pulmonary embolism were included in the study. Patients were divided into two groups based on the duration of symptoms at presentation: symptoms of < or =72 h, group A; symptoms of >72 h, group B. Serum cardiac troponin I levels were measured at presentation. RESULTS: Mean age was 63+/-18 years and 23 (40%) patients were males. Thirty-three (58%) patients had symptoms of < or =72 h (group A) and 24 (42%) had symptoms of >72 h (group B). Both groups had similar prevalence of right ventricular dysfunction on echocardiography (55% [n=18] in group A vs. 42% [n=10] in group B, p=NS). Sixteen patients had elevated serum cardiac troponin I (mean+/-S.D. 3.3+/-2.3 ng/ml, range 0.6-8.3 ng/ml). Elevated serum cardiac troponin I was strongly associated with right ventricular dysfunction (p=0.015). All patients with elevated serum cardiac troponin I (n=16) were in group A (p<0.0001). Twelve of 18 (67%) patients with (p=0.0005) and 4 of 15 (27%) patients without (p=NS) right ventricular dysfunction had elevated serum cardiac troponin I. Thirteen of 16 (81%) patients with elevated serum cardiac troponin I had duration of symptoms < or =24 h at presentation. CONCLUSIONS: The dynamics of cardiac troponin I release in acute pulmonary embolism in patients who present with symptoms of < or =72 h duration could be different from those who present with longer duration of symptoms. Therefore, the use of cardiac troponin I in risk stratification of acute pulmonary embolism might be limited to the patients presenting within 72 h of the onset of symptoms.     

Incremental prognostic value of troponin I and echocardiography in patients with acute pulmonary embolism.

BACKGROUND: To test the hypothesis that troponin I and echocardiography have an incremental prognostic value in patients with pulmonary embolism (PE). METHODS AND RESULTS: In 91 patients with acute PE, echocardiography was performed within 4h of admission. Troponin I levels were obtained on admission and 12h thereafter. The 0.06 microg/l troponin I cut-off level was identified as the most useful, high-sensitivity cut-off level for the prediction of adverse outcome by receiver operating characteristic analysis with a sensitivity and specificity of 86%, respectively. Twenty-eight (31%) patients had elevated troponin I levels (4.9+/-3.8 microg/l). Twenty-one (23%) patients had adverse clinical outcomes including in-hospital death in five, cardiopulmonary resuscitation in four, mechanical ventilation in six, pressors in 14, thrombolysis in 14, catheter fragmentation in three, and surgical embolectomy in three. The area under the receiver operating characteristic curve from multivariate regression models for predicting adverse outcome without troponin I and echocardiography (0.765), with troponin I (0.890) or echocardiography alone (0.858), and the combination of both tests (0.900) was incremental. Three-month survival rate was highest in patients with both a normal troponin I level and a normal echocardiogram (98%). Positive predictive value for adverse clinical outcomes of the combination of echocardiography and troponin I was higher (75% (95%CI 55-88%)) compared with each test alone (echocardiography: 41%, 95% CI 28-56%; troponin I: 64%, 95% CI 46-79%). CONCLUSIONS: While troponin I measurements added most of the prognostic information for identifying high-risk patients, a normal echocardiogram combined with a negative troponin I level was most useful to identify patients at lowest risk for early death.