Summary:High-dose cyclophosphamide (HD-CTX) is largely employed in high-dose chemotherapy (HD-CHT) protocols. HD-CTX dose-limiting toxicity expresses itself as cardiac toxicity which is fatal in a minority of patients. The pathophysiology of HD-CTX-associated cardiotoxicity is still poorly understood. Autopsy studies in patients who died from acute HD-CTX-induced cardiac toxicity revealed hemorrhagic myocardial cell death and interstitial edema. Recently troponins, in particular troponin I (cTnI), have been found to represent a uniquely sensitive and specific marker of myocyte membrane integrity and therefore to increase in response to minimal myocardial cell damage in different settings, including doxorubicin-induced cardiotoxicity. We performed a multiparametric cardiologic monitoring in 16 consecutive breast cancer patients undergoing HD-CTX by means of serial ECG registrations and cardiac enzymes (CPK, CPK-MB and cTnI) determinations plus echocardiography in order to clarify acute cardiac events following HD-CTX administration. Neither overt cardiac toxicity nor cardiac enzymes elevation were recorded. Serial ECGs revealed in six cases little and reversible reduction of QRS voltage and/or ST abnormalities. Echo monitoring showed in four cases mild and transient increase of LV diastolic/systolic diameter/volume without decrease of FS% or EF% below normal values: in two of them abnormalities of diastolic function (E/A mitral doppler ratio) were also recorded. We conclude that our protocol of HD-CTX administration does not cause myocardial cell damage as analyzed by serum cTnI levels, thus suggesting that myocyte membrane injury may not be the first direct mechanism of HD-CTX cardiotoxicity. ECG (ie QRS voltages ) and Echo (ie E/A ratio) monitoring leads us to hypothesize that slight interstitial edema with reduction of LV diastolic compliance may be initial signs of cardiac dysfunction in this clinical setting. Bone Marrow Transplantation (2001) 28, 277-282.
Background: To investigate the frequency of cardiac troponin I (cTnI) increases in patients with pulmonary embolism (PE) and to assess the correlation between this finding, the clinical presentation, and outcomes. Methods: Consecutive patients admitted to the coronary care unit with acute PE were prospectively enrolled between January 2000 and December 2001. cTnI was sequentially determined. Various cut off concentrations were analysed, but patients were categorised prospectively as having increased or no increased cTnI based on a cut off concentration of 0.6 ng/ml. The main outcome measure was in-hospital mortality. Results: On admission, 14 of the 48 patients (29%) had cTnI concentrations greater than the receiver operating characteristic curve value used to diagnose acute myocardial infarction (. 0.6 ng/ml). Subsequently, six patients developed increases for an overall prevalence of 42% (20 of 42). The prevalence was higher when lower cut off concentrations were used: 73% (35 of 48) at the 99th centile and 60% (29 of 48) at the 10% coefficient of variability. Increased cTnI . 0.6 ng/ml was associated with a slower oxygen saturation (86 (7)% v 93 (4)%, p , 0.0001) and more frequent involvement of the main pulmonary arteries as assessed by spiral computed tomography (100% v 60%, p = 0.022). In-hospital mortality was 36% (5 of 14) of patients with increases . 0.6 ng/ml v 3% (1 of 42) of patients with lower concentrations (p = 0.008). Increased cTnI . 0.6 ng/ml on admission was the most powerful predictor of mortality (p = 0.046). Conclusions: In high risk patients with acute PE, cTnI was frequently detected on admission. It was the strongest independent predictor of mortality.
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