Gender differences in the evaluation of coronary artery disease with a cadmium-zinc telluride camera

Association between CZT‑SPECT myocardial blood flow and coronary stenosis: A cross‑sectional study

The association between the quantitative and semi-quantitative parameters of myocardial blood flow obtained using cadmium-zinc-telluride single photon emission computed tomography (CZT-SPECT) and coronary stenosis remains unclear. Therefore, the objective of the present study was to evaluate the diagnostic value of two parameters obtained using CZT-SPECT in patients with suspected or known coronary artery disease. A total of 24 consecutive patients who underwent CZT-SPECT and coronary angiography within 3 months of each other were included in the study. To evaluate the predictive ability of the regional difference score (DS), coronary flow reserve (CFR), and the combination thereof for positive coronary stenosis at the vascular level, receiver operating characteristic (ROC) curves were plotted and the area under the curves (AUCs) were calculated. Comparisons of the reclassification ability for coronary stenosis between different parameters were assessed by calculating the net reclassification index (NRI) and the integrated discrimination improvement (IDI). The 24 participants (median age: 65 years; range: 46-79 years; 79.2% male) included in this study had a total of 72 major coronary arteries. When stenosis ≥50% was defined as the criteria for positive coronary stenosis, the AUCs and the 95% confidence interval (CI) for regional DS, CFR, and the combination of the two indices were 0.653 (CI, 0.541-0.766), 0.731 (CI, 0.610-0.852) and 0.757 (CI, 0.645-0.869), respectively. Compared with single DS, the combination of DS and CFR increased the predictive ability for positive stenosis, with an NRI of 0.197-1.060 (P<0.01) and an IDI of 0.0150-0.1391 (P<0.05). When stenosis ≥75% was considered as the criteria, the AUCs were 0.760 (CI, 0.614-0.906), 0.703 (CI, 0.550-0.855), and 0.811 (CI, 0.676-0.947), respectively. Compared with DS, CFR had an IDI of -0.3392 to -02860 (P<0.05) and the combination of DS and CFR also enhanced the predictive ability, with an NRI of 0.0313-1.0758 (P<0.01). In conclusion, both regional DS and CFR had diagnostic values for coronary stenosis, but the diagnostic abilities differed in distinguishing between different degrees of stenosis, and the efficiency was improved with a combination of DS and CFR.

Prediction of angiographic coronary disease and mortality with a cadmium-zinc-telluride camera: a comparison of upright and supine ejection fractions and left ventricular volumes

Introduction

Perfusion imaging strongly predicts coronary artery disease (CAD), whereas cardiac volumes and left ventricular ejection fraction (LVEF) strongly predict mortality. Compared to conventional Anger single-photon emission computed tomography (SPECT) cameras, cadmium-zinc-telluride (CZT) cameras provide higher resolution, resulting in different left ventricular volumes. The cadmium-zinc-telluride D-SPECT camera is commonly used to image in the upright position, which introduces changes in left ventricular loading conditions and potentially alters left ventricular volumes. However, little or no data exist on the predictive value of left ventricular volumes and ejection fraction when acquired in the upright position. We investigated models for the prediction of CAD and mortality, comparing upright and supine imaging.

Methods

A retrospective study of patients with upright/supine stress and rest imaging and coronary angiography within 3 months was performed. Univariate and multivariable analyses were performed to predict abnormal angiograms and all-cause mortality.

Results

Of the 392 patients, 210 (53.6%) had significant angiographic CAD; 78 (19.9%) patients died over 75 months. The best multivariable model for CAD included the supine summed stress score and supine stress LVEF, with an area under the receiver operating characteristic of 0.862, a sensitivity of 76.7%, and a specificity of 82.4%, but this model was not statistically superior to the best upright model. The best multivariable models for mortality included age, diabetes, history of cardiovascular disease, and end-systolic volume, with the upright and supine models being equivalent.

Discussion

Angiographic CAD was best predicted by the supine summed stress score and LVEF but was not statistically superior to the next-best upright model. Mortality was best predicted by end-systolic volume in combination with age, diabetes status, and cardiovascular disease status, with equivalent results from the upright and supine images.

Mitigating bias in deep learning for diagnosis of coronary artery disease from myocardial perfusion SPECT images

PURPOSE

Artificial intelligence (AI) has high diagnostic accuracy for coronary artery disease (CAD) from myocardial perfusion imaging (MPI). However, when trained using high-risk populations (such as patients with correlating invasive testing), the disease probability can be overestimated due to selection bias. We evaluated different strategies for training AI models to improve the calibration (accurate estimate of disease probability), using external testing.

METHODS

Deep learning was trained using 828 patients from 3 sites, with MPI and invasive angiography within 6 months. Perfusion was assessed using upright (U-TPD) and supine total perfusion deficit (S-TPD). AI training without data augmentation (model 1) was compared to training with augmentation (increased sampling) of patients without obstructive CAD (model 2), and patients without CAD and TPD < 2% (model 3). All models were tested in an external population of patients with invasive angiography within 6 months (n = 332) or low likelihood of CAD (n = 179).

RESULTS

Model 3 achieved the best calibration (Brier score 0.104 vs 0.121, p < 0.01). Improvement in calibration was particularly evident in women (Brier score 0.084 vs 0.124, p < 0.01). In external testing (n = 511), the area under the receiver operating characteristic curve (AUC) was higher for model 3 (0.930), compared to U-TPD (AUC 0.897) and S-TPD (AUC 0.900, p < 0.01 for both).

CONCLUSION

Training AI models with augmentation of low-risk patients can improve calibration of AI models developed to identify patients with CAD, allowing more accurate assignment of disease probability. This is particularly important in lower-risk populations and in women, where overestimation of disease probability could significantly influence down-stream patient management.

Effects of gender and defect reversibility on detection of coronary disease with an upright and supine cadmium-zinc-telluride camera

BACKGROUND

Limited data address the roles of gender, perfusion defect reversibility, and imaging position in interpretation of images acquired on an upright/supine cadmium-zinc-telluride (CZT) cardiac imaging system.

METHODS AND RESULTS

From a consecutive cohort of patients imaged on an upright/supine CZT camera, 260 patients with coronary angiograms were studied. Multivariable models identified gender as a significant effect modifier for imaging variables of CAD. For males, a supine summed stress score (SSS) ≥ 3 provided high accuracy (sensitivity 70.7%, specificity 72.2%), and highest contribution to multivariable models. In females, supine SSS ≥ 2 provided the best cut-off for defect size and severity (sensitivity 90%, specificity 35.9%), but specificity was improved substantially to 53.3% with decrease in sensitivity to 80% by also requiring quantitative identification of perfusion defect reversibility in the supine position. Eight variables, accurate for predicting coronary disease, were more accurate with supine than upright imaging.

CONCLUSIONS

Perfusion defect reversibility improved specificity in female patients for detection of coronary disease compared to perfusion defect size and extent alone. Supine images provided superior accuracy for detection of coronary disease compared to upright images.

Noise heterogeneity in attenuation-corrected cardiac SPECT images increases perfusion value uncertainty near the base of the heart

BACKGROUND

Dedicated cardiac SPECT cameras which employ multi-pinhole detectors have variable photon sensitivity within the camera's field-of-view such that a lower number of photon counts is typically detected from the base of the heart than from the apex. Consequently, the noise in a reconstructed image is expected to be higher at the base than at the apex of the heart.

METHODS

Patient emission images were resampled to create statistical replicates which were reconstructed with and without attenuation correction. Noise images were computed using one standard deviation of the replicated images. These were evaluated for 93 patients with normal study results, each imaged with both a dual-headed parallel-hole camera and a multi-pinhole camera. Statistics for a normal database (NDB) of images from the 93 patients were also calculated.

RESULTS

Image noise (1.7-fold) and NDB uncertainty (1.3-fold) increase significantly from the apex-to-the base of the heart in attenuation-corrected multi-pinhole SPECT images. The differences for non-attenuation-corrected images or those acquired with a parallel-hole camera were not significant.

CONCLUSIONS

For best interpretation of attenuation-corrected images acquired with multi-pinhole cameras, knowledge of NDB uncertainty gradients should be taken into consideration.

Head-to-head comparison of diagnostic accuracy of stress-only myocardial perfusion imaging with conventional and cadmium-zinc telluride single-photon emission computed tomography in women with suspected coronary artery disease

BACKGROUND

Breast attenuation may impact the diagnostic accuracy of stress myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT). We compared the performance of conventional (C)-SPECT and cadmium-zinc-telluride (CZT)-SPECT systems in women with low-intermediate likelihood of coronary artery disease (CAD).

METHODS AND RESULTS

A total of 109 consecutive women underwent stress-optional rest MPI by both C-SPECT and CZT-SPECT. In the overall study population, a weak albeit significant correlation between total perfusion defect (TPD) measured by C-SPECT and CZT-SPECT was observed (r = 0.38, P < .001) and at Bland-Altman analysis the mean difference in TPD (C-SPECT minus CZT-SPECT) was 2.40% (P < .001). Overall concordance of semi-quantitative diagnostic performance between C-SPECT and CZT-SPECT was observed in 52 (48%) women with a κ value of 0.09. Normalcy rate was significantly higher using CZT-SPECT compared to C-SPECT (P < .001). Machine learning analysis performed through the implementation of J48 algorithm proved that CZT-SPECT has higher sensitivity, specificity, and accuracy than C-SPECT.

CONCLUSIONS

In women with low-intermediate likelihood of CAD, there is a poor concordance of diagnostic performance between C-SPECT and CZT-SPECT, and CZT-SPECT allows better normalcy rate detection compared to C-SPECT.

State of the Art in Noninvasive Imaging of Ischemic Heart Disease and Coronary Microvascular Dysfunction in Women: Indications, Performance, and Limitations

PURPOSE OF REVIEW

Establishing a diagnosis of ischemic heart disease (IHD) in women, including assessment for coronary microvascular dysfunction (CMD) when indicated, can be challenging. Access to performance of invasive testing when appropriate may be limited, and noninvasive imaging assessments have evolved. This review will summarize the various noninvasive imaging modalities available for the diagnosis of IHD and CMD in women, outlining indications, performance modalities, advantages, and limitations.

RECENT FINDINGS

While stress echocardiography and single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) are widely available and can detect IHD in women, their ability to specifically identify CMD is limited. Novel developments in cardiac magnetic resonance (CMR) imaging, including spectroscopy, and positron emission tomography (PET) have changed the diagnostic landscape. Coronary computed tomographic angiography (CCTA), while unable to diagnose CMD, is developing an emerging role in the risk stratification of ischemic syndromes. Despite the discovery of increased CMD prevalence in symptomatic women and technological advances in diagnostic imaging, practitioners are limited by user expertise and center availability when choosing a diagnostic imaging modality. Knowledge of this evolving field is imperative as it highlights the need for sex-specific assessment of cardiovascular syndromes.

Diagnostic value of stress thallium-201/rest technetium-99m-sestamibi sequential dual isotope high-speed myocardial perfusion imaging for the detection of haemodynamically relevant coronary artery stenosis

BACKGROUND

The aim of this study was to determine the diagnostic accuracy of stress thallium-201/rest technetium-99m-sestamibi sequential dual-isotope high-speed myocardial perfusion imaging (DI-HS-MPI) against invasively determined fractional flow reserve (FFR).

METHODS

Fifty-four consecutive patients prospectively underwent DI-HS-MPI before invasive coronary angiography. Perfusion was scored visually by summed stress score on a patient and coronary territory basis. Significant coronary artery disease (CAD) was defined by the presence of ≥ 90% stenosis/occlusion or fractional flow reserve ≤ 0.80 for coronary stenosis ≥ 50%.

RESULTS

FFR was measured in 69 of 162 coronary vessels, with 1.28 ± 0.56 vessels assessed/patient. Sensitivity, specificity, and diagnostic accuracy of MPI for the detection of significant CAD were 92.8%, 69.2%, and 81.4%, on a patient basis, and 83.7%, 90.4%, and 88.8% by coronary territory.

CONCLUSIONS

DI-HS-MPI accurately detects functionally significant CAD as defined by using FFR.

The radiation dose to overweighted patients undergoing myocardial perfusion SPECT can be significantly reduced: validation of a linear weight-adjusted activity administration protocol

BACKGROUND

Large body size can cause a higher proportion of emitted photons being attenuated within the patient. Therefore, clinical myocardial perfusion SPECT (MPS) protocols often include unproportionally higher radioisotope activity to obese patients. The aim was to evaluate if a linear weight-adjusted low-dose protocol can be applied to obese patients and thereby decrease radiation exposure.

METHODS AND RESULT

Two hundred patients (>110 kg, BMI 18-41, [n = 69], ≤ 110 kg, BMI 31-58, [n = 131]) underwent 99mTc-tetrofosmin stress examination on a Cadmium Zinc Telluride or a conventional gamma camera using new generations of reconstruction algorithm (Resolution Recovery). Patients <110 kg were administered 2.5 MBq/kg, patients between 110 and 120 kg received 430 MBq and patients >120 kg received 570 MBq according to clinical routine. Patients >110 kg had 130% total number of counts in the images compared to patients <110 kg. Recalculating the counts to correspond to an administered activity of 2.5 MBq/kg resulted in similar number of counts across the groups. Image analyses in a subgroup with images corresponding to high activity and 2.5 MBq/kg showed no difference in image quality or ischemia quantification.

CONCLUSION

Linear low-dose weight-adjusted protocol of 2.5 MBq/kg in MPS can be applied over a large weight span without loss of counts or image quality, resulting in a significant reduction in radiation exposure to obese patients.

Myocardial perfusion imaging in women for the evaluation of stable ischemic heart disease-state-of-the-evidence and clinical recommendations

This document from the American Society of Nuclear Cardiology represents an updated consensus statement on the evidence base of stress myocardial perfusion imaging (MPI), emphasizing new developments in single-photon emission tomography (SPECT) and positron emission tomography (PET) in the clinical evaluation of women presenting with symptoms of stable ischemic heart disease (SIHD). The clinical evaluation of symptomatic women is challenging due to their varying clinical presentation, clinical risk factor burden, high degree of comorbidity, and increased risk of major ischemic heart disease events. Evidence is substantial that both SPECT and PET MPI effectively risk stratify women with SIHD. The addition of coronary flow reserve (CFR) with PET improves risk detection, including for women with nonobstructive coronary artery disease and coronary microvascular dysfunction. With the advent of PET with computed tomography (CT), multiparametric imaging approaches may enable integration of MPI and CFR with CT visualization of anatomical atherosclerotic plaque to uniquely identify at-risk women. Radiation dose-reduction strategies, including the use of ultra-low-dose protocols involving stress-only imaging, solid-state detector SPECT, and PET, should be uniformly applied whenever possible to all women undergoing MPI. Appropriate candidate selection for stress MPI and for post-MPI indications for guideline-directed medical therapy and/or invasive coronary angiography are discussed in this statement. The critical need for randomized and comparative trial data in female patients is also emphasized.

Myocardial perfusion scintigraphy dosimetry: optimal use of SPECT and SPECT/CT technologies in stress-first imaging protocol

Purpose

Over the past decade, nuclear medicine experts have been seeking to minimize patient exposure to radiation in myocardial perfusion scintigraphy (MPS). This review describes the latest technological innovations in MPS, particularly with regard to dose reduction.

Methods

We searched in PubMed for original clinical papers in English, published after 2008, using the following research criteria: (dose) and ((reduction) or (reducing)) and ((myocardial) or (cardiac) or (heart)) and ((nuclear medicine) or (nuclear imaging) or (radionuclide) or (scintigraphy) or (SPET) or (SPECT)). Thereafter, recent reviews on the topic were considered and other relevant clinical papers were added to the results.

Results

Of 202 non-duplicate articles, 17 were included. To these, another eight papers cited in recent reviews were added. By optimizing the features of software, i.e., through algorithms for iterative reconstruction with resolution recovery (IRRs), and hardware, i.e., scanners and collimators, and by preferring, unless otherwise indicated, the use of stress-first imaging protocols, it has become possible to reduce the effective dose by at least 50% in stress/rest protocols, and by up to 89% in patients undergoing a diagnostic stress-only study with new technology. With today’s SPECT/CT systems, the use of a stress-first protocol can conveniently be performed, resulting in an overall dose reduction of about 35% if two-thirds of stress-first examinations were considered definitively normal.

Conclusion

Using innovative gamma cameras, collimators and software, as well as, unless otherwise indicated, stress-first imaging protocols, it has become possible to reduce significantly the effective dose in a high percentage of patients, even when X-ray CT scanning is performed for attenuation correction.

The role of pharmacological stress testing in women

Pharmacological stress is an alternative method to dynamic exercise that combined with noninvasive imaging allows the detection of flow-limiting coronary artery disease (CAD). It represents the stress procedure of choice in patients who cannot exercise appropriately. In women, pharmacological stress combined with myocardial perfusion scintigraphy (MPS) has demonstrated to be highly accurate for the detection of obstructive CAD and a valuable tool that helps separate patients at low cardiac risk from those with an adverse prognosis. Pharmacological stress with positron emission tomographic (PET) imaging is increasingly used in the investigation of suspected obstructive CAD; available evidence shows that the diagnostic profile and prognostic value of stress PET imaging is similar to that of stress MPS in women.

Performance of cardiac cadmium-zinc-telluride gamma camera imaging in coronary artery disease: a review from the cardiovascular committee of the European Association of Nuclear Medicine (EANM)

The trade-off between resolution and count sensitivity dominates the performance of standard gamma cameras and dictates the need for relatively high doses of radioactivity of the used radiopharmaceuticals in order to limit image acquisition duration. The introduction of cadmium-zinc-telluride (CZT)-based cameras may overcome some of the limitations against conventional gamma cameras. CZT cameras used for the evaluation of myocardial perfusion have been shown to have a higher count sensitivity compared to conventional single photon emission computed tomography (SPECT) techniques. CZT image quality is further improved by the development of a dedicated three-dimensional iterative reconstruction algorithm, based on maximum likelihood expectation maximization (MLEM), which corrects for the loss in spatial resolution due to line response function of the collimator. All these innovations significantly reduce imaging time and result in a lower patient's radiation exposure compared with standard SPECT. To guide current and possible future users of the CZT technique for myocardial perfusion imaging, the Cardiovascular Committee of the European Association of Nuclear Medicine, starting from the experience of its members, has decided to examine the current literature regarding procedures and clinical data on CZT cameras. The committee hereby aims 1) to identify the main acquisitions protocols; 2) to evaluate the diagnostic and prognostic value of CZT derived myocardial perfusion, and finally 3) to determine the impact of CZT on radiation exposure.

Comparison of the diagnostic accuracies of very low stress-dose with standard-dose myocardial perfusion imaging: Automated quantification of one-day, stress-first SPECT using a CZT camera

BACKGROUND

Previous studies have demonstrated accurate diagnosis of reduced dose myocardial perfusion imaging (MPI) using Cadmium-Zinc-Telluride (CZT) technology. We compared the diagnostic performances of very low stress-dose (<2 mSv) with standard-dose stress-first, quantitative MPI using a CZT camera.

METHODS

Patients without known coronary artery- disease who underwent a stress-first Tc-99 m sestamibi CZT-MPI and invasive coronary angiography (ICA), and low-risk patients without ICA were included. A stress-rest standard-dose (10/30 mCi) MPI and a low-dose (5/15 mCi) MPI were compared. Normal limits for quantification were developed from 40 (20 males) low-risk patients, and total perfusion deficit (TPD) was derived.

RESULTS

208 patients who underwent MPI and ICA, and 76 low-risk patients were included. Of these, 128 had a standard-dose MPI and 156 had a low-dose MPI. Stress-doses in low-dose and standard-dose groups were 5.9 ± 1.2 vs 10.2 ± 0.5 mCi (1.7 ± 0.3 vs 3.0 ± 0.1 mSv), respectively, P < 0.001, and stress-rest effective radiation was 6.9 ± 1.1 vs 11.7 ± 0.4 mSv, respectively, P < 0.001. Sensitivity, specificity, and accuracy values in the low-dose and standard-dose groups were 86.1%, 76.6%, and 81.4%; and 90.6%, 78.1%, and 84.4%, respectively, P = ns. Using TPD prone, specificity values were 84.9% and 80.3%, respectively, P = ns.

CONCLUSION

One-day stress-first MPI with 50% radiation reduction and a very low stress-dose (<2 mSv) using CZT technology and quantitative supine and prone analysis provided a high diagnostic value, similar to standard-dose MPI.

Stress thallium-201/rest technetium-99m sequential dual-isotope high-speed myocardial perfusion imaging validation versus invasive coronary angiography

BACKGROUND

Recent advances in nuclear myocardial perfusion imaging (MPI) have made it possible to develop a dual-isotope protocol for high-speed acquisition with image quality and radiation delivery comparable to that obtained with conventional single isotope protocols. So far, no study has compared dual-isotope high-speed MPI to invasive coronary angiography (ICA) in a large cohort using a Cadmium-zinc-telluride SPECT system.

METHODS

Over a 1-year period (May 2011 to April 2012), 1366 patients underwent dual-isotope high-speed MPI. Patients with ICA within 3 months after dual-isotope high-speed MPI were included together with patients with a low likelihood of coronary artery disease (CAD) in order to assess normalcy rate. Global summed stress score (SSS) and summed rest score (SRS) were calculated, and ICA results were analyzed independently. The main end point was a patient-based assessment of the diagnostic performance of dual-isotope high-speed MPI in detecting or ruling out significant CAD (>70% reduction in lumen diameter).

RESULTS

Inclusion criteria were fulfilled for 214 patients (143 men; age 60 ± 14 years; ICA, n = 104; low likelihood for CAD, n = 110). An exercise stress test was performed in 62% of patients and a pharmacological stress test was performed with either dipyridamole (32%) or dobutamine (6%). Average examination duration was 22.4 ± 4.5 minutes. Mean SSS, SRS, and SDS were 8.0 ± 4.9, 3.1 ± 4.3, and 5.0 ± 3.2, respectively. Prevalence of angiographic CAD was 75%. ICA detected stenosis in the left main trunk, left anterior descending artery, left circumflex artery, and right coronary artery in 4, 33, 31, and 42 patients, respectively. Sensitivity of dual-isotope high-speed MPI was 94%, normalcy rate was 92%, and accuracy was 83% for detecting CAD.

CONCLUSION

Dual-isotope high-speed MPI is reliable at detecting or ruling out CAD. NCT01785589.

A performance comparison of novel cadmium-zinc-telluride camera and conventional SPECT/CT using anthropomorphic torso phantom and water bags to simulate soft tissue and breast attenuation

PURPOSES

This study was aimed to compare the physical performances of cadmium-zinc-telluride (CZT) camera and conventional Anger camera. An anthropomorphic torso phantom and water bags to simulate breasts were used to evaluate artifacts arising from soft tissue attenuation.

MATERIALS AND METHODS

Linear source studies were performed to evaluate extrinsic resolution of CZT camera (Discovery NM 530c, GE) and conventional single-photon emission computed tomography (SPECT) Anger camera (Symbia T2, Siemens). Three sets of phantom experiments: cardiac phantom only (phantom H), anthropomorphic torso phantom added (phantom T), and torso phantom with water bags attached (phantom B), with Tc-99m were performed on both scanners. Imaging performances were evaluated through count sensitivity, contrast-to-noise ratio, quantitative sharpness profile, wall thickness, perfusion uniformity (measured by standard deviation of perfusion percentage of 20 segments using quantitative perfusion SPECT (QPS) software, Cedars-Sinai), and visual imaging quality (using 20-segment sum defect scores (SDS) of QPS) for CZT camera, conventional SPECT without and with computed tomography transmission attenuation correction (AC).

RESULTS

CZT cameras had higher extrinsic resolution than conventional SPECT. Myocardium count sensitivity of CZT camera is about threefold of conventional SPECT. Contrast-to-noise ratios and sharpness profiles are higher on CZT camera but degraded while extracardiac soft tissue presented. Myocardial walls measured on CZT images were thicker. Images of CZT had lower SDS, while AC reduced the differences of SDS between CZT and CC. Perfusion images from CZT had the better uniformity than SPECT without or with AC. Breast attenuation was less prominent on CZT camera than conventional SPECT, while inferior and inferolateral segments still suffer marked soft tissue attenuation on CZT camera.

CONCLUSIONS

CZT camera has better physical performance and image quality with less artificial perfusion defects than conventional SPECT. CZT camera also has less breast attenuation than conventional SPECT. However, extracardiac soft tissue may degrade the superior performance of CZT camera, and attenuation correction methods are still needed to solve the attenuation issues in inferior and inferolateral myocardium.

Evaluation of left ventricular diastolic function with a dedicated cadmium-zinc-telluride cardiac camera: comparison with Doppler echocardiography

AIMS

To evaluate the relationships between measures of left ventricular (LV) filling dynamics at cadmium-zinc-telluride (CZT) imaging and indexes of LV diastolic function at transthoracic echocardiography.

METHODS AND RESULTS

Two hundred and forty-seven patients underwent myocardial perfusion imaging at rest and after stress with a low-dose CZT protocol and a baseline transthoracic echocardiography study. All patients were submitted to invasive or computed coronary angiography. The peak filling rate (PFR) and the time to PFR (TPFR) were derived from gated CZT images as measures of LV filling dynamics. LV diastolic function was also evaluated at echocardiography and the presence of significantly increased LV filling pressures determined. Increased LV filling pressures at transthoracic echocardiography were evident in 103 (42%) patients. Interestingly, independently from the presence of coronary artery disease, there was a strict correlation between the presence and severity of LV diastolic dysfunction at echocardiography and CZT-derived measures of filling dynamics, i.e., PFR (P = 0.001) and TPFR (P = 0.001). At receiving operating characteristic analysis, a composite index of reduced PFR (≤2.11 end-diastolic volume s(-1)) and increased TPFR (>234 ms) showed a sensitivity of 84% and a specificity of 67% in unmasking the presence of elevated LV filling pressures at echocardiography.

CONCLUSIONS

CZT-derived measures of LV filling dynamics correlate with echocardiographic parameters of diastolic function and may identify the presence of increased LV filling pressures.