Related Experiment Video
Updated: May 12, 2026
In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography
Published on: February 16, 2016
Quantitative myocardial contrast echocardiography: a new method for the non-invasive detection of chronic heart
Tobias Rutz1, Stefano F de Marchi, Patrizia Roelli
1Department of Cardiology, University Hospital Bern, CH-3010 Bern, Switzerland.
Insights
Myocardial contrast echocardiography effectively detects severe cardiac allograft vasculopathy (CAV) after heart transplantation. A relative blood volume (rBV) of less than 14% accurately identifies significant intima thickness, a key indicator of CAV.
Area of Science:
- Cardiology
- Transplantation Medicine
- Diagnostic Imaging
Background:
- Cardiac allograft vasculopathy (CAV) is a primary cause of poor prognosis following heart transplantation (HTx).
- Accurate detection of severe CAV is crucial for patient management.
Purpose of the Study:
- To evaluate the efficacy of relative myocardial blood volume (rBV) measured by myocardial contrast echocardiography (MCE) in detecting severe CAV.
- To compare MCE-derived rBV with coronary intravascular ultrasound (IVUS) findings.
Main Methods:
- Quantitative IVUS was used to assess intima thickness (>1 mm defined as severe CAV).
- Transthoracic MCE was performed at rest to measure rBV and coronary conductance (β).
- Correlation between IVUS-determined intima thickness and MCE-derived rBV was analyzed.
Main Results:
- Severe CAV was present in 69% of patients.
- Patients with severe CAV had significantly lower resting rBV (0.12 ± 0.07) compared to those without (0.17 ± 0.05).
- Resting rBV <0.14 demonstrated high accuracy (AUC=0.844, sensitivity=0.90, specificity=0.75) in detecting severe CAV.
Conclusions:
- Non-invasive quantitative MCE can accurately detect severe CAV.
- A resting rBV value below 14% is a reliable indicator of significant coronary intima thickness (>1 mm) as confirmed by IVUS.
Background:
Chronic heart transplant rejection, i.e. cardiac allograft vasculopathy (CAV) is a major adverse prognostic factor after heart transplantation (HTx). This study tested the hypothesis that the relative myocardial blood volume (rBV) as quantified by myocardial contrast echocardiography accurately detects severe CAV as defined by coronary intravascular ultrasound (IVUS).
Methods And Results:
Forty-five HTx patients underwent a total of 50 quantitative IVUS measurements for intima thickness assessment (>1 mm = severe CAV; the reference method). Simultaneously, the two factors constituting myocardial perfusion (mL/min/g) were obtained by transthoracic contrast echocardiography at rest: rBV (the test method), a measure of microvascular density (mL/mL), and its exchange rate β (1/s; a measure of coronary conductance) after mechanical contrast bubble disruption.Sixty-nine per cent (31 of 45) of the HTx patients showed severe CAV. rBV at rest was equal to 0.17 ± 0.05 in the group without severe CAV, and it was equal to 0.12 ± 0.07 in the group with severe CAV (P = 0.0157). Conversely, β amounted to 6.4 ± 4.5 in the former and to 10.3 ± 6.2 in the latter group (P = 0.0410), thus, maintaining normal resting myocardial perfusion at 1 mL/min/g. IVUS determined intima thickness correlated significantly and inversely with rBV at rest. An rBV value at rest <0.14 accurately detected severe CAV (intima thickness >1 mm): area under the receiver operating characteristics curve = 0.844, P = 0.004, sensitivity = 0.90, specificity = 0.75.
Conclusion:
Severe CAV can be detected using the non-invasive method of quantitative myocardial contrast echocardiography. rBV at rest amounting to <14% of the surrounding tissue accurately detects coronary intima thickness >1 mm as determined invasively by IVUS.
Clinical Trial Number:
NCT00414895.
