Comparative prediction of cardiac events by wall motion, wall motion plus coronary flow reserve, or myocardial perfusion analysis: a multicenter study of contrast stress echocardiography

Reversible ischaemia and outcome after adjustment for coronary artery disease severity: a multicentre stress-echocardiography registry

AIMS

To assess the potential association of reversible ischaemia and Doppler coronary flow velocity reserve in the left anterior descending coronary artery (CFVR-LAD) during stress echocardiography (SE) with all-cause mortality and non-fatal myocardial infarction (MI), after correction for anatomic coronary artery disease (CAD) burden and other significant clinical variables.

METHODS AND RESULTS

We selected 3191 patients (mean age 66 ± 12 years) from our multicentre SE registry, who underwent both high-dose dipyridamole SE (comprehensive of CFVR-LAD measurement) and coronary angiography within 2 months. All-cause mortality and non-fatal MI were the primary end points. The association of the primary end point with ischaemia severity and CFVR-LAD was assessed, after multivariable adjustment for all other significant clinical and imaging variables, including anatomic CAD severity by the modified Duke Prognostic Index. The primary end point occurred in 767 (24%) patients (death in 409 and non-fatal MI in 375 patients) during a median follow-up of 42 months. Multivariable Cox regression analyses indicated that, among other significant variables, anatomic CAD severity, reversible ischaemia, and CFVR-LAD were all independently associated with the primary end point; reversible ischaemia was also associated with subsequent MI, while CFVR-LAD with mortality, independent of anatomic CAD severity.

CONCLUSION

Our study suggests that reversible ischaemia by wall motion assessment and CFVR-LAD on dipyridamole SE are independently associated with dismal outcome in patients with suspected or known stable CAD, even after accounting for angiographic anatomic CAD severity and also independently from which coronary artery is diseased.

Contrast Stress Echocardiography Findings in Myocardial Bridging Compared to Normal Coronary Course, With and Without Coronary Artery Disease

BACKGROUND

Myocardial bridging (MB) correlation with ischemia remains a diagnostic challenge. There is a lack of studies that have assessed MB using contrast stress echo and compared the findings with those in patients demonstrating a normal coronary course, with or without obstructive coronary artery disease (CAD).

METHODS

We evaluated all consecutive patients who underwent contrast stress echocardiography and coronary computed tomography angiography (CCTA) due to suspected symptoms of CAD within 3 months in Parma Hospital. Coronary computed tomography angiography served as the reference standard for detecting MB and obstructive CAD. The patients were divided into 3 groups: (1) MB and no evidence of obstructive CAD (MB group, N = 64), (2) no evidence of obstructive CAD or MB (NoCAD group, N = 135), (3) obstructive CAD without MB (CAD group, N = 68).

RESULTS

The coronary flow velocity reserve in the LAD (CFVR-LAD) was reduced in the MB and CAD groups, measuring 1.91 ± 0.21 and 1.82 ± 0.28, respectively, whereas it was 2.27 ± 0.34 in the NoCAD group (P < .001). The MB and CAD groups exhibited a higher prevalence of reversible myocardial perfusion defects (rMPDs) compared to the NoCAD group (57.8% vs 64.7% vs 3.7%, P < .001). Reversible wall motion abnormalities were frequently observed in the CAD group and rarely found in the MB and NoCAD groups (47.1% vs 18.8% vs 4.4%, P < .001). In multivariable analyses, the presence of MB was independently associated with reduced CFVR-LAD (odds ratio = 14.55; 95% CI, 6.84-30.93; P < .001) and the presence of rMPD (odds ratio = 37.96; 95% CI, 13.49-106.84; P < .001). Patients with deep MB (>2 mm depth) and very deep MB (≥5 mm depth) exhibited significantly greater CFVR-LAD reduction and rMPD than those with superficial MB.

CONCLUSIONS

Myocardial bridging is capable of inducing rMPD and reducing CFVR-LAD similar to obstructive CAD. The depth of the MB correlates with the abnormalities found in the stress echo evaluation. Contrast stress echo may serve as a valuable noninvasive tool for evaluating patients with MB.

Coronary flow reserve and cardiovascular outcomes: a systematic review and meta-analysis

AIMS

This meta-analysis aims to quantify the association of reduced coronary flow with all-cause mortality and major adverse cardiovascular events (MACE) across a broad range of patient groups and pathologies.

METHODS AND RESULTS

We systematically identified all studies between 1 January 2000 and 1 August 2020, where coronary flow was measured and clinical outcomes were reported. The endpoints were all-cause mortality and MACE. Estimates of effect were calculated from published hazard ratios (HRs) using a random-effects model. Seventy-nine studies with a total of 59 740 subjects were included. Abnormal coronary flow reserve (CFR) was associated with a higher incidence of all-cause mortality [HR: 3.78, 95% confidence interval (CI): 2.39-5.97] and a higher incidence of MACE (HR 3.42, 95% CI: 2.92-3.99). Each 0.1 unit reduction in CFR was associated with a proportional increase in mortality (per 0.1 CFR unit HR: 1.16, 95% CI: 1.04-1.29) and MACE (per 0.1 CFR unit HR: 1.08, 95% CI: 1.04-1.11). In patients with isolated coronary microvascular dysfunction, an abnormal CFR was associated with a higher incidence of mortality (HR: 5.44, 95% CI: 3.78-7.83) and MACE (HR: 3.56, 95% CI: 2.14-5.90). Abnormal CFR was also associated with a higher incidence of MACE in patients with acute coronary syndromes (HR: 3.76, 95% CI: 2.35-6.00), heart failure (HR: 6.38, 95% CI: 1.95-20.90), heart transplant (HR: 3.32, 95% CI: 2.34-4.71), and diabetes mellitus (HR: 7.47, 95% CI: 3.37-16.55).

CONCLUSION

Reduced coronary flow is strongly associated with increased risk of all-cause mortality and MACE across a wide range of pathological processes. This finding supports recent recommendations that coronary flow should be measured more routinely in clinical practice, to target aggressive vascular risk modification for individuals at higher risk.

The left ventricular ejection fraction: new insights into an old parameter

Accurate evaluation of cardiac function has become increasingly important as the treatment of cardiac disease has become more complex. At the same time, technological advances allow greater accuracy and precision in cardiac measurements. Measurement of left ventricular ejection fraction (LVEF) has been a pillar of cardiac evaluation. Several noninvasive modalities are available to assess LVEF; each has advantages and limitations. This review examines various modalities used to measure LVEF and focuses on the relative strengths and weaknesses of each modality. In some clinical settings, however, LVEF may be too insensitive to convey subtle changes in LV contractility. In certain clinical situations, use of LVEF may be an insufficient measure of left ventricular systolic function. Global longitudinal strain is one such parameter that has shown promise for detecting subtle reductions in left ventricular contractility in subjects with chemotherapy-induced cardiotoxicity.

Stress echocardiography in coronary artery disease: a practical guideline from the British Society of Echocardiography

Stress echocardiography is an established technique for assessing coronary artery disease. It has primarily been used for the diagnosis and assessment of patients presenting with chest pain in whom there is an intermediate probability of coronary artery disease. In addition, it is used for risk stratification and to guide revascularisation in patients with known ischaemic heart disease. Although cardiac computed tomography has recently been recommended in the United Kingdom as the first-line investigation in patients presenting for the first time with atypical or typical angina, stress echocardiography continues to have an important role in the assessment of patients with lesions of uncertain functional significance and patients with known ischaemic heart disease who represent with chest pain. In this guideline from the British Society of Echocardiography, the indications and recommended protocols are outlined for the assessment of ischaemic heart disease by stress echocardiography.

Imaging functional stress test for stable chest pain symptoms in patients at low pretest probability of coronary artery disease: Current practice and long-term outcome

BACKGROUND

Stress testing in patients with low pretest probability (PTP) of coronary artery disease (CAD) has become an increasing practice, potentially leading to underestimation of its true clinical value. Our aim was to describe the current use of most employed imaging functional tests and their prognostic value.

METHODS AND RESULTS

We selected patients with low PTP of CAD (CAD consortium clinical score < 15%) who underwent exercise or dipyridamole stress echocardiography or single photon emission computed tomography for suspected angina. Main exclusions were age < 45, known CAD, and abnormal rest wall motion. Of the 2279 subjects undergoing stress test, 883 (39%) had low PTP, and 91 (10.3%) had a positive test for ischemia. After a median follow-up of 5.8 years, 36 patients had events (21 died, 14 had nonfatal myocardial infarction). The percentage of events in the abnormal and normal stress test groups were similar (5 [5.5%] vs 31 [3.9%], P = ns), as the annualized event rate (0.87% vs 0.62%, P = ns). Age was the only variable associated with outcome in the regression analysis (hazard ratio 1.072, 95% CI 1.034-1.113, P < 0.001). An abnormal result was not associated with worse outcome in each of the subgroups of functional tests.

CONCLUSIONS

In our geographical area, a considerable proportion of patients undergoing imaging functional tests for stable chest pain have a low estimated PTP of CAD. Of these, 1 in 10 resulted positive for inducible ischemia. However, none of the most common imaging functional tests, single photon emission computed tomography (SPECT), and stress echocardiography offer prognostic information in these patients.

Association of coronary artery Doppler-echocardiography diastolic-systolic velocity ratio at rest with obstructive coronary artery stenosis on the left main or left anterior descending coronary artery

BACKGROUND

We assessed whether the non-invasive measure of peak diastolic-systolic velocity ratio (rDSVR) at rest on the left anterior descending artery (LAD) using Doppler transthoracic echocardiography is associated with obstructive coronary artery disease (CAD) on the LAD and left main (LM) arteries. We compared rDSVR diagnostic accuracy with stress wall motion (WM) and coronary flow reserve (CFR-LAD), in a group of subjects who underwent contrast stress-echocardiography (cSE) and coronary angiography within 3 months.

METHODS

286 patients selected with a clinical indication to cSE, in which CFR-LAD was measured during the test who also underwent coronary angiography within 3 months were selected and diagnostic performance compared.

RESULTS

Demographics and clinical variables were univariate predictors of LAD or LM >50% stenosis, but rDSVR < 1.7 outperformed other variables (OR 11.18, 95% CI 5.82-21.49, p < 0.001), comprising cSE variables such as reversible WM abnormalities (OR 1.53, 95% CI 0.94-2.49, p = 0.087) or CFR-LAD < 2 (OR 2.88, 95% CI 21.74-4.77, p < 0.001). The addition of rDSVR to multivariate logistic regression models (clinical or clinical + cSE variables) led to a marked increase in C-index (0.82, 95%CI 0.78-0.87) with significant improvement compared to all prior models (p < 0.001).

CONCLUSIONS

Our data suggest a strict association of reduced rDSVR with >50% coronary artery stenosis on the LM/LAD, superior to other standard clinical or cSE related indexes, such as WM assessment or CFR-LAD, and builds incrementally to them and clinical variables in multivariable logistic models for the prediction of CAD on LM and LAD coronaries.

Shenzhu Guanxin Recipe Granules () for Improving Exercise Tolerance in Patients with Stable Angina (SERIES Trial): A Protocol of Multicenter, Randomized, Double-Blind, Placebo Parallel Controlled Clinical Trial

BACKGROUND

Many patients with chronic angina experience anginal episodes despite successful recanalization, antianginal and antiischemic medications. Empirical observations suggested that Shenzhu Guanxin Recipe Granules (, SGR), a Chinese herbal compound, exerted potential impacts on increased treadmill exercise performance and angina relieve. However, there has been no systematic study to clarify the impact of SGR on exercise tolerance in patients with stable angina. The SERIES (ShEnzhu guanxin Recipe for Improving Exercise tolerance in patients with Stable angina) trial is designed to determine the effects of SGR on exercise duration, electrocardiographic (ECG) evidence of myocardial ischemia, and incidence of major adverse cardiac events (MACE) in stable anginal patients.

METHODS

A total of 184 eligible patients with stable angina will be randomly assigned to receive placebo or SGR (10 g/day for 12 weeks) in a 1:1 ratio. The primary outcome will be the change from baseline in total exercise tolerance duration, time to onset of angina and ECG ischemia during exercise treadmill testing performed over a 12-week study period. The secondary outcome will include ECG measures, the occurrence and composite of MACE and the Seattle Angina Questionnaire score. Moreover, the coronary microcirculation will be evaluated to explore the possible effects in response to treatment of SGR. After the procedure, all participants will be followed up by interview at 3 and 6 months, enquiring about any cardiac events, hospitalizations, cardiac functional level and medication usage. Additionally, the occurrence of adverse events will be evaluated at each follow-up.

DISCUSSION

This study may provide novel evidence on the efficacy of SGR in improving exercise tolerance and potentially reducing clinical adverse events. (Trial registration No. ChiCTR-TRC-14004504).

Stress Echocardiography: Need to Optimize its Appropriate Use in Suspected Angina and a Review of Available Additional Tools for its Clinical Application in 2018: First do no Harm! Second do it at the Highest Possible Accuracy

There is a need to reassess the most appropriate indications for stress echocardiography in the current era, in patients with suspect or known coronary artery disease (CAD), and also the most helpful additional parameters that can be easily calculated in clinical practice to increase the known suboptimal sensitivity for obstructive CAD of this test. The current review tries to clarify what is and what should be the proper role for functional testing in general, but specifically regarding modern stress echocardiography in the current practice, for suspected CAD and/or atypical chest pain. Few candidate additional parameters beyond wall motion assessment are here suggested to improve diagnostic accuracy of stress echocardiography, and pertinent literature is briefly reviewed, together with a more personal view of the author regarding the characteristics of each parameter, as far as ease of acquisition, cost, and true diagnostic or prognostic clinical usefulness are concerned. The reviewed additional parameters, which can be acquired during stress echocardiography, are Doppler coronary flow reserve in the left anterior descending artery, cardiac calcium score, global longitudinal strain, ventricular elastance, and contrast myocardial perfusion. Each of them finds a potential place in the current practice or may find a place in the future practice of stress echocardiography.

Clinical practice of contrast echocardiography: recommendation by the European Association of Cardiovascular Imaging (EACVI) 2017

Contrast echocardiography is widely used in cardiology. It is applied to improve image quality, reader confidence and reproducibility both for assessing left ventricular (LV) structure and function at rest and for assessing global and regional function in stress echocardiography. The use of contrast in echocardiography has now extended beyond cardiac structure and function assessment to evaluation of perfusion both of the myocardium and of the intracardiac structures. Safety of contrast agents have now been addressed in large patient population and these studies clearly established its excellent safety profile. This document, based on clinical trials, randomized and multicentre studies and published clinical experience, has established clear recommendations for the use of contrast in various clinical conditions with evidence-based protocols.

Equivocal tests after contrast stress-echocardiography compared with invasive coronary angiography or with CT angiography: CT calcium score in mildly positive tests may spare unnecessary coronary angiograms

Background

Imaging stress tests are not ideally accurate to predict anatomically obstructive CAD, leading to a non-trivial rate of unnecessary iCA. This may depend on the threshold used to indicate iCA, and maybe CTA or, one step earlier, CT calcium score could spare most unnecessary iCA in only mildly positive cSE. We assessed the diagnostic accuracy of contrast stress-echocardiography (cSE) in comparison with invasive coronary angiography (iCA), and CT angiography (CTA) only in case of equivocal tests, to find hints helping reduce falsely positive cSE in the suspicion of coronary artery disease (CAD).

Methods

Patients who were indicated cSE for suspected CAD between 2012 and 2016, who also underwent iCA were selected and diagnostic results compared. A second group, specifically with equivocal cSE who underwent CTA was also analyzed.

Results

137 subjects with equivocal cSE and CTA and 314 with cSE (any result) and iCA were selected. In the CTA-equivocal cSE group, an Agatston score < 105 and a coronary flow reserve (CFR-LAD) <1.7 had very high negative predictive value (99%, 92% respectively) to exclude obstructive CAD. The Agatston score was the most significant incremental predictor of CAD beyond clinical variables (chi square 31 to 47, p < 0.001). In the iCA group a more-than-mild reversible wall motion abnormality (WMA) demonstrated high positive predictive value for CAD (89%), while CFR-LAD appeared less useful. More-than-mild reversible WMA was the most significant predictor of CAD beyond clinical variables (chi square 37.5 to 56, p < 0.001).

Conclusions

Our data suggest iCA should be indicated only for more-than-mild reversible WMA at cSE, due to the very high positive predictive value for CAD of this finding, while mildly positive tests should be shifted to non-invasive CT, with CTA performed only for coronary calcium Agatston score > 100, since lower scores demonstrated very high negative predictive value for CAD, not justifying proceeding to CTA and even less to iCA.

Coronary flow reserve/diastolic function relationship in angina-suffering patients with normal coronary angiography

AIMS

Coronary blood flow and diastolic function are well known to interfere with each other through mechanical and metabolic mechanisms. We aimed to assess the relationship between coronary flow reserve (CFR) and diastolic dysfunction in patients suffering from angina but with normal coronary angiography.

METHODS

In 16 patients with chest pain and angiographically normal coronary arteries, CFR was measured using transthoracic echo-Doppler by inducing hyperemia through dipyridamole infusion. Diastolic function (E/A, deceleration time, isovolumetric relaxation time [IVRT], propagation velocity [Vp]) and left ventricular mass were evaluated by means of two-dimensional transthoracic echocardiography.

RESULTS

The patients were initially divided into two groups on the grounds of CFR only (ACFR: altered CFR, n = 9; NACFR: unaltered CFR, n = 7). Thereafter they were divided into four groups on the grounds of CFR and diastolic function (NN: normal; AA: altered CFR/diastole; AN: altered CFR/normal diastole; NA: normal CFR/altered diastole). Most of the subjects were scheduled in AA (n = 8) or NA (n = 5) groups, which were taken into consideration for further analysis. Patients were not different regarding various risk factors. ACFR and AA patients were older with normal body weight in comparison with NACFR and NA patients (P < 0.05). In the AA group, CFR and diastolic variables were found to be related to each other.

CONCLUSION

Diastolic dysfunction and reduced CFR were correlated in patients with concomitant alterations of those variables only. Because most risk factors were shared with patients with altered diastolic properties only, our findings could represent a direct relationship between altered CFR and diastole.

Effect of Coronary Revascularization on the Prognostic Value of Stress Myocardial Contrast Wall Motion and Perfusion Imaging

Background

The assessment of myocardial perfusion (MP) and wall motion (WM) using contrast dipyridamole echocardiography (cSE‐WMP) improves the sensitivity to detect coronary artery disease and the stratification of cardiac events, but its long‐term value for fatal and nonfatal ischemic cardiac events, also with respect to patients undergoing revascularization or not, remains to be determined.

Methods and Results

One‐thousand three‐hundred and twenty‐nine patients with suspect or known CAD who underwent cSE‐WMP were followed for a median 5.5 years. The independent prognostic value of cSE‐WMP regarding cardiac death or nonfatal myocardial infarction was related to stress WM and MP, rest ejection fraction, clinical risk factors, and medications. Patients revascularized after cSE‐WMP were separately analyzed to determine whether the procedure influenced outcome and whether this depends on cSE‐WMP results. A total of 125 cardiac fatal and nonfatal ischemic events (9.4%) occurred during the follow‐up (61 deaths, 64 myocardial infarctions). The 5‐year event rate with normal MP and WM was 5.9%, 9.9% with isolated MP defects (normal WM), and 15.5% with both MP and WM abnormalities. In patients not undergoing revascularization (n=1111), reversible MP defects added discrimination value over WM response and clinical factors/medication data (P=0.001), while in the cohort undergoing revascularization (n=218), cSE‐WMP results did not influence outcome.

Conclusions

cSE‐WMP, with both contrast MP and WM assessments, provides independent, incremental prognostic information regarding ischemic cardiac events at 5 years in patients with known or suspected coronary artery disease. Revascularization reduces cardiac events after an abnormal cSE‐WMP, resulting in outcomes not different from those in patients with normal cSE‐WMP.

Coronary Artery Imaging with Transthoracic Doppler Echocardiography

Coronary artery imaging with transthoracic Doppler echocardiography is a simple and useful technique to diagnose significant coronary artery stenosis. The visualization of mosaic flow in the proximal left coronary artery provides a direct indication of the presence of significant stenosis at the corresponding site during routine echocardiography. Coronary flow velocity reserve (CFVR) has a high diagnostic accuracy and feasibility in detecting the presence of functionally significant coronary stenosis in the left anterior descending coronary artery (LAD) and in the right coronary artery. The measurement of CFVR in the LAD also provides prognostic information in patients with intermediate coronary stenosis. This review summarizes the utility of transthoracic coronary artery imaging.

Simultaneous Assessment of Myocardial Perfusion, Wall Motion, and Deformation during Myocardial Contrast Echocardiography: A Feasibility Study

AIMS

Ultrasound contrast agents may be used for the assessment of regional wall motion and myocardial perfusion, but are generally considered not suitable for deformation analysis. The aim of our study was to assess the feasibility of deformation imaging on contrast-enhanced images using a novel methodology.

METHODS AND RESULTS

We prospectively enrolled 40 patients who underwent stress echocardiography with continuous intravenous infusion of SonoVue for the assessment of myocardial perfusion imaging with flash replenishment technique. We compared longitudinal strain (Lε) values, assessed with a vendor-independent software (2D CPA), on 68 resting contrast-enhanced and 68 resting noncontrast recordings. Strain analysis on contrast recordings was evaluated in the first cardiac cycles after the flash. Tracking of contrast images was deemed feasible in all subjects and in all views. Contrast administration improved image quality and increased the number of segments used for deformation analysis. Lε of noncontrast and contrast-enhanced images were statistically different (-18.8 ± 4.5% and -22.8 ± 5.4%, respectively; P < 0.001), but their correlation was good (ICC 0.65, 95%CI 0.42-0.78). Patients with resting wall-motion abnormalities showed lower Lε values on contrast recordings (-18.6 ± 6.0% vs. -24.2 ± 5.5%, respectively; P < 0.01). Intra-operator and inter-operator reproducibility was good for both noncontrast and contrast images with no statistical differences.

CONCLUSIONS

Our study shows that deformation analysis on postflash contrast-enhanced images is feasible and reproducible. Therefore, it would be possible to perform a simultaneous evaluation of wall-motion abnormalities, volumes, ejection fraction, perfusion defects, and cardiac deformation on the same contrast recording.

Stress echocardiography: what is new and how does it compare with myocardial perfusion imaging and other modalities?

Cardiovascular disease is a leading cause of morbidity and mortality, and noninvasive strategies to diagnose and risk stratify patients remain paramount in the evaluative process. Stress echocardiography is a well-established, versatile, real-time imaging modality with advantages including lack of radiation exposure, portability, and affordability. Innovative techniques in stress echocardiography include myocardial contrast echocardiography, deformation imaging, three-dimensional (3D) echocardiography, and assessment of coronary flow reserve. Myocardial perfusion imaging with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) are imaging alternatives, and stress cardiac magnetic resonance imaging and coronary computed tomography (CT) angiography, including CT perfusion imaging, are emerging as newer approaches. This review will discuss recent and upcoming developments in the field of stress testing, with an emphasis on stress echocardiography while highlighting comparisons with other modalities.

Myocardial perfusion echocardiography and coronary microvascular dysfunction

Our understanding of coronary syndromes has evolved in the last two decades out of the obstructive atherosclerosis of epicardial coronary arteries paradigm to include anatomo-functional abnormalities of coronary microcirculation. No current diagnostic technique allows direct visualization of coronary microcirculation, but functional assessments of this circulation are possible. This represents a challenge in cardiology. Myocardial contrast echocardiography (MCE) was a breakthrough in echocardiography several years ago that claimed the capability to detect myocardial perfusion abnormalities and quantify coronary blood flow. Research demonstrated that the integration of quantitative MCE and fractional flow reserve improved the definition of ischemic burden and the relative contribution of collaterals in non-critical coronary stenosis. MCE identified no-reflow and low-flow within and around myocardial infarction, respectively, and predicted the potential functional recovery of stunned myocardium using appropriate interventions. MCE exhibited diagnostic performances that were comparable to positron emission tomography in microvascular reserve and microvascular dysfunction in angina patients. Overall, MCE improved echocardiographic evaluations of ischemic heart disease in daily clinical practice, but the approval of regulatory authorities is lacking.

Update on cardiac imaging techniques 2013

Cardiac imaging is a cornerstone of diagnosis in heart conditions, and an essential tool for assessing prognosis and establishing treatment decisions. This year, echocardiography stands out as a guide in interventional procedures and in choosing the size of the prosthesis. It is also proving to be a valuable technique in low-flow, low-gradient aortic stenosis. Three-dimensional echocardiography is advancing our knowledge of cardiac anatomy and valvular measurements. The parameters indicating tissue deformation have predictive power in valve disease and in the follow-up of drug-induced cardiotoxicity. Single-photon emission computed tomography and positron emission tomography are proving useful in ischemic heart disease and in the diagnosis of cardiac inflammation and infections. The role of computed tomography has been strengthened in noninvasive coronary angiography, the emergency room management of chest pain, assessment of chronic occlusions, and morphologic study of coronary plaque. Cardiac magnetic resonance imaging remains the gold standard for tissue characterization in ischemic heart disease and cardiomyopathies, and is assuming a greater role in stress studies and in the assessment of myocardial viability.

Integrating anatomical and functional imaging for the assessment of coronary artery disease

Coronary artery disease (CAD) is a leading cause of morbidity and mortality. Invasive cardiac angiography with fractional flow reserve measurement allows for the anatomical and functional assessment of CAD. Given the invasive nature of invasive cardiac angiography and the risks of procedure-related complications, research has focused upon noninvasive methods for anatomical and functional measures of CAD. As such, there is growing interest in the development of hybrid imaging because it may provide incremental diagnostic information over each imaging modality alone. We will provide an overview of the evidence to date on the anatomical and functional stratification of CAD and current hybrid techniques.