Early Change in Area Strain Detected by 3D Speckle Tracking Is Associated With Subsequent Cardiotoxicity in Patients Treated With Low Doses of Anthracyclines

Objective

To evaluate the prognostic impact of the parameters of myocardial deformation using three-dimensional speckle tracking echocardiography (3DSTE) in patients with breast cancer who underwent chemotherapy with low doses of anthracyclines.

Background

Chemotherapy-related cardiotoxicity has an important prognostic impact on cancer survivors. Three-dimensional STE has revealed more consistent data than two-dimensional techniques and may represent a more accurate tool in the evaluation of myocardial function in patients who underwent chemotherapy.

Methods

We evaluated patients with breast cancer who were treated with anthracyclines (associated or not with trastuzumab) in five stages: baseline, after cumulative doses of 120 and 240 mg/m² of doxorubicin, and then, after 6 months and at least 1 year after anthracyclines. Ultrasensitive troponin I (US-TnI) and a standard echocardiography study were performed at each stage. We analyzed left ventricular ejection fraction (LVEF) by Simpson's method, two-dimensional speckle tracking (2DSTE) with longitudinal and radial strain values, and 3DSTE with longitudinal, radial, and circumferential strain as well as twist, torsion, rotation, and three-dimensional global area strain (3DGAS). Cardiotoxicity was defined as a decrease in LVEF by more than 10 percentage points to a value lower than 53%.

Results

We evaluated 51 female patients who were aged 50.6 ± 11 years. After the cumulative dose of 240 mg/m² of doxorubicin, US-TnI was increased (>34 pg/ml) in 21 patients (45%, p > 0.001), LVEF remained unchanged (p = 0.178), while 2DSTE longitudinal strain was decreased (from −17.8% to −17.1%, p < 0.001) and 3DSTE detected changes in longitudinal, radial, circumferential, and area strain. After a lower cumulative dose of doxorubicin (120 mg/m²), 3DGAS (p < 0.001) was the only parameter that was changed. In the follow-up, 7 (13%) patients presented a decrease in LVEF. Three-dimensional GAS early changed to abnormal values was the only variable associated with a subsequent decrease in LVEF (definitive cardiotoxicity).

Conclusion

In patients with breast cancer, 3DSTE detected early changes in area strain after very low doses of doxorubicin. The 3DGAS early changed to abnormal values was associated with a subsequent decrease in LVEF, representing a promising technique to predict chemotherapy-induced cardiomyopathy.

1186 Three-dimensional analysis of right ventricle strain in transplanted hearts and rejection: an ongoing prospective study

Background

The main obstacle for success after heart transplantation is graft rejection, since is mainly asymptomatic and diagnosed by endomyocardial biopsy (EMB). New echocardiographic technologies could bring benefits to that population if subtle changes in heart mechanics were related to an incipient state of rejection.

Purpose

To quantify echocardiographic parameters of right ventricle strain and volumes by a semi-automated offline software and to identify the presence of any relation between those findings and the histopathologic diagnose of rejection.

Methods

a prospective cohort of 35 postoperative heart transplant patients who were submitted to echocardiographic evaluation up to six hours after EMB, including two-dimensional chamber quantification of left ventricular (LV) volumes and ejection fraction; conventional and tissue Doppler measurements were used for flow and functional analysis. Offline assessment of the right ventricle (RV) was made by TOMTEC software, with the acquisition of RV volumes (EDV, ESV, SV) and ejection fraction, TAPSE, FAC and three-dimensional(3D) RV free wall and septal strain using speckle tracking. EMB results were classified as positive for cellular rejection if graded as 2R (two or more interstitial infiltrate spots and myocyte damage) and positive for humoral rejection if they show any response by immunofluorescence assay.

Results

We studied 35 patients, aged 50 ±11, 21 male (67%), totaling 58 examinations, and then we made two analysis of EMB: one in two groups regarding cellular rejection (53 negative and 5 positive) and other regarding humoral rejection (50 negative and 8 positive). RVEDV was higher in the cellular rejection group (112,5 ± 29,6 ml) compared to those with negative biopsy (86,8 ± 24,7 mL; p = 0,01). RV stroke volume showed a similar behavior (53,5 ± 22,3 mL vs. 34,5 ± 11,3 mL; p &lt; 0,01). Regarding humoral rejection by immunofluorescence, patients who tested positive showed lower RVEDV (79,5 ± 10,5 mL vs. 90,57 ± 27,31 mL; p = 0,02) and RVESV (45,53 ± 6,33 mL vs. 53,87 ± 19,87 mL; p = 0,01). RV free wall strain was lower in the group with positive immunofluorescence (-18,35 ± 2,79% vs. -15,34 ± 5,35%; p = 0,01). Regarding 2D measurements , interventricular septal (11,5 ± 1,06 mm vs. 10,56 ± 1,38 mm; p = 0,02) and left ventricular posterior wall (10,75 ± 1,03 mm vs. 10,04 ± 1,1 mm; p = 0,05) were also thicker in the group with positive immunofluorescence for rejection.

Conclusion

Both cellular and humoral rejection after heart transplantation are associated to increased 3D RV volumes whereas a decrease in RV free wall strain is only observed in humoral rejection; in patients with positive immunofluorescence results a significant increase is seen for septal and posterior wall thickness.

Betabloqueador tópico pode determinar resultados inconclusivos no ecocardiograma sob estresse com dobutamina em pacientes com glaucoma

Dobutamine stress echocardiography is a well-established method to assess coronary artery disease, of which sensitivity has been enhanced by adding atropine at the end of the protocol. Individuals with glaucoma, a disease with a high prevalence in patients with cardiac diseases older than 40 years, cannot benefit from the use of atropine as it is contraindicated for this group of patients. Additionally, these individuals are often treated with topical betablockers (eye drops), which can have systemic effects by decreasing cardiac frequency, blood pressure and pulmonary capacity. The aim of our study was to verify whether a possible systemic effect caused by the use of these eye drops, yielding a low chronotropic response, could result in inconclusive dobutamine stress echocardiography in patients with glaucoma.

Infarct Size Assessment in Mice

Genetically modified mice are used extensively in models of ischemia reperfusion (I/R) and nonreperfused myocardial infarction (MI) to gain insights into pathways involved in these pathologies. Echocardiography is an ideal noninvasive tool to serially monitor the cardiac murine phenotype. The present review details the surgical aspects of I/R and MI models and the measurement of MI size by pathology techniques and the input of echocardiographic techniques including the extent of wall motion abnormality and of perfusion defects using myocardial contrast echocardiography in the assessment of murine area at risk and MI size.

Coronary flow reserve impairment predicts cardiac events in heart transplant patients with preserved left ventricular function

BACKGROUND

The impact of allograft vasculopathy on the coronary circulation and consequently on cardiac outcome may be expressed by coronary flow reserve (CFR) impairment. Therefore, we aimed to evaluate CFR and its relation to cardiac events in heart transplant patients.

METHODS

Twenty-three patients, 2 female, with left ventricular ejection fraction >45% were studied 76+/-30 months after heart transplantation. They were divided into 2 groups according to coronary angiography: Group A, 10 patients with significant coronary artery disease (stenosis> or =50%) and group B, 13 patients without significant stenosis. Twenty healthy subjects, 13 female, served as controls. Coronary flow velocity reserve (CFVR) was assessed by transesophageal echocardiography and calculated as the ratio of maximal (i.v. adenosine, 140 microg/kg/min) to baseline coronary velocities. Patients were followed for a mean of 25 months for cardiac events.

RESULTS

Compared to controls, heart transplant groups showed significantly higher baseline coronary flow velocities (51+/-27, 38+/-12 and 32+/-12 cm/s, respectively) and lower maximal coronary velocities (90+/-52, 112+/-33 and 118+/-24 cm/s), resulting in a reduced CFVR (1.9+/-1.0, 3.0+/-0.5 and 3.8+/-1.2). Multivariate analysis identified heart transplantation and epicardial coronary artery disease as the only variables independently related to CFVR. Hypertension was positively related to baseline while diabetes inversely related to maximal coronary flow velocities. A CFVR <2.3 was a marker for cardiac events (4 deaths, 1 heart failure).

CONCLUSION

CFVR impairment, particularly in the presence of epicardial coronary artery disease, follows heart transplantation and is associated with a worse outcome.

Papillary Muscle Rupture After Blunt Chest Trauma

We report a case of anterolateral papillary muscle rupture in a 22-year-old man who had blunt chest trauma caused by a car accident. Transesophageal echocardiography revealed severe mitral regurgitation caused by the rupture. He successfully underwent emergency mitral valve replacement and was discharged 9 days after the surgical correction.

Quantitative Assessment of Regional Myocardial Function in Mice by Tissue Doppler Imaging

Background— Tissue Doppler imaging (TDI) is a novel echocardiographic method to quantify regional myocardial function. The objective of this study was to assess whether myocardial velocities and strain rate (SR) could be obtained by TDI in mice and whether these indices accurately quantified alterations in left ventricular (LV) systolic function.

Methods and Results— TDI was performed in 10 healthy mice to measure endocardial (v endo ) and epicardial systolic velocities and SR. In further experiments, TDI indices were compared with dP/dt max and with sonomicrometer-derived regional velocities, at rest and after administration of dobutamine or esmolol. TDI indices were also studied serially in 8 mice before and 4 and 7 hours after endotoxin challenge. Myocardial velocities and SR were obtained in all mice with low measurement variability. TDI indices increased with administration of dobutamine (v endo from 2.2±0.3 to 3.8±0.2 cm/s [ P <0.01]; SR from 12±2 to 20±2 s −1 [ P <0.05]) and decreased with administration of esmolol (v endo 1.4±0.2 cm/s [ P <0.05]; SR 6±1 s −1 [ P <0.01]). Both indices correlated strongly with dP/dt max ( r 2 =0.79 for SR and r 2 = 0.69 for v endo ; both P <0.0001). SR and shortening fraction were predictors of dP/dt max even after adjustment for the confounding effect of the other variables. V endo correlated closely with sonomicrometer-measured velocity ( r 2 =0.71, P <0.0005). After endotoxin challenge, decreases in both v endo and SR were detected before decreases in shortening fraction became manifest.

Conclusions— Myocardial velocities and SR can be measured noninvasively in mice with the use of TDI. Both indices are sensitive markers for quantifying LV global and regional function in mice.

The imbalance between coronary reserve and wall stress explains the severity of ventricular dysfunction in hypertension

BACKGROUND

The pathophysiologic role of coronary reserve impairment in hypertensive cardiac dysfunction is still debated. Previously, we demonstrated that satisfactory coronary vasodilatation may coexist with ventricular systolic dysfunction. It is conceivable that coronary reserve might otherwise be inappropriate for enhanced myocardial oxygen demand and may thus affect cardiac performance negatively.

HYPOTHESIS

Myocardial supply-demand imbalance contributes to the severity of ventricular dysfunction in hypertension (HTN).

METHODS

Fractional shortening (%) and end-systolic stress (10(3) x dyn x cm(-2)) were determined using echocardiography, and coronary reserve was calculated using transesophageal Doppler echocardiography. Coronary reserve/stress (cm2 x dyn(-1)) was utilized as a measure of supply-demand. Groups NL (20 healthy subjects), HTN1 (15 patients, fractional shortening > or = 30), HTN2 (19 patients, 20 < or = fractional shortening < 30), and HTN3 (21 patients, fractional shortening < 20) were constituted.

RESULTS

Compared with NL and HTN1, groups HTN2 and HTN3 had significantly (p < 0.05) greater end-systolic stress (NL = 72 +/- 16, HTN1 = 72 +/- 23, HTN2 = 143 +/- 32, HTN3 = 186 +/- 70). Coronary reserve was impaired in HTN3 alone (NL = 3.5 +/- 0.6, HTN1 = 3.4 +/- 1.0, HTN2 = 3.1 +/- 1.0, HTN3 = 2.6 +/- 1.1), but coronary reserve/stress was reduced in both HTN2 and HTN3 (NL = 50 +/- 12, HTN1 = 53 +/- 21, HTN2 = 22 +/- 7, HTN3 = 15 +/- 7). Stepwise regression analysis identified diastolic internal dimension, end-systolic stress, and coronary reserve/stress as independently associated with fractional shortening.

CONCLUSION

The imbalance between supply-demand explains the severity of hypertensive cardiac dysfunction and adds information to cardiac enlargement and elevated wall stress.

Noninvasive detection of coronary allograft vasculopathy by myocardial contrast echocardiography

BACKGROUND

Noninvasive detection of coronary allograft vasculopathy is still challenging. To determine the accuracy of myocardial contrast echocardiography (MCE) in detecting coronary allograft vasculopathy after heart transplantation, we studied 35 asymptomatic patients (30 men, aged 46 +/- 12.7 years) with normal left ventricular function.

METHODS

Patients underwent MCE with continuous contrast (perfluorocarbon-exposed sonicated dextrose albumin) administration. Images were obtained at baseline and during peak dobutamine (up to 40 mg/kg/min) with intermittent harmonic imaging. Areas failing to increase contrast enhancement during peak stress were regarded as abnormal. Coronary artery obstructions greater than 50% at angiography were considered significant.

RESULTS

Seven out of 10 patients with coronary artery disease had a positive MCE and one patient with a positive MCE had no angiographically detected disease (sensitivity = 70%, specificity = 96%, accuracy = 88.6%). Agreement between the vascular territory and perfusion defects was good for the left anterior descending coronary artery (kappa = 0.56), but not for other arteries. Although 5 patients had multivessel disease, multiple perfusion defects were detected in only one patient.

CONCLUSION

MCE showed good accuracy in detecting the presence of coronary allograft vasculopathy after heart transplantation; however, it failed to identify the extent of the disease.