Diagnostic Imaging Strategies for Patients with Suspected Coronary Artery Disease

In this thesis, our aim was to determine and optimize the diagnostic work-up for patients who are suspected of having coronary artery disease (CAD). We showed that the diagnostic performance of stress perfusion magnetic resonance imaging (MRI) compares favorably to the diagnostic performance of single-photon emission computed tomography (SPECT). If both tests can be performed in a patient, then stress perfusion MRI should be the preferred test, even more so because it does not involve exposure to radiation. We demonstrated that the coronary CT calcium score has predictive value beyond existing cardiovascular risk factors for diagnosing obstructive CAD in patients with chest pain. The CT coronary calcium score could be considered as an initial triage test in patients with a low pre-test probability of CAD, preventing (unnecessary) further work-up if the score is zero, and justifying further testing when coronary calcium is present. The optimal diagnostic strategy depends on the pre-test probability of CAD, which is traditionally estimated based on the Diamond & Forrester method or the Duke Clinical Score. We demonstrated that these prediction rules systematically overestimate the probability of CAD and we updated the models based on contemporary data. An online probability calculator was developed that provides systematically lower (but more accurate) estimates of the pre-test probability. Although we did not study the clinical impact of implementing our new prediction model, a more accurate estimate of the pre-test probability is likely to lead to better decisions regarding further testing and it could potentially reduce costs since less high probabilities are predicted which in turn may prevent unnecessary diagnostic work-up. Lastly, we evaluated the long term effectiveness and costs of coronary CT angiography in various different settings and for various countries. In the Dutch setting, coronary CT angiography was found to be cost-effective as triage test prior to catheter-based coronary angiography (CAG) if the pre-test probability was below 44% in men and below 37% in women. CT coronary calcium scoring with or without subsequent coronary CT angiography as initial strategy for patients presenting with stable chest pain was less expensive and equally effective compared to standard-of-care. Finally, we showed that a strategy using coronary CT angiography, if positive followed by cardiac magnetic resonance imaging (CMR) was cost-effective compared to strategies with coronary CT angiography and CMR alone, for the United States, the United Kingdom, as well as the Netherlands. All-in-all, our updated prediction models combined with the results from our decision models and cost-effectiveness analyses provide a practical framework for efficient implementation of diagnostic imaging tests, in particular for the CT coronary calcium score and coronary CT angiography

Diagnostic performance of stress myocardial perfusion imaging for coronary artery disease: A systematic review and meta-analysis

Objectives To determine and compare the diagnostic performance of stress myocardial perfusion imaging (MPI) for the diagnosis of obstructive coronary artery disease (CAD), using conventional coronary angiography (CCA) as the reference standard. Methods We searched Medline and Embase for literature that evaluated stress MPI for the diagnosis of obstructive CAD using magnetic resonance imaging (MRI), contrastenhanced echocardiography (ECHO), single-photon emission computed tomography (SPECT) and positron emission tomography (PET). Results All pooled analyses were based on random effects models. Articles on MRI yielded a total of 2,970 patients from 28 studies, articles on ECHO yielded a sample size of 795 from 10 studies, articles on SPECT yielded 1,323 from 13 studies. For CAD defined as either at least 50 %, at least 70 % or at least 75 % lumen diameter reduction on CCA, the natural logarithms of the diagnostic odds ratio (lnDOR) for MRI (3.63; 95 % CI 3.26-4.00) was significantly higher compared to that of SPECT (2.76; 95 % CI 2.28-3.25; P=0.006) and that of ECHO (2.83; 95 % CI 2.29-3.37; P=0.02). There was no significant difference between the lnDOR of SPECT and ECHO (P=0.52). Conclusion Our results suggest that MRI is superior for the diagnosis of obstructive CAD compared with ECHO and SPECT. ECHO and SPECT demonstrated similar diagnostic performance. Key Points ̇ MRI can assess myocardial perfusion. ̇ MR perfusion diagnoses coronary artery disease better than echocardiography or SPECT. ̇ Echocardiography and SPECT have similar diagnostic performance. ̇ MRI can save coronary artery disease patients from more invasive tests. ̇ MRI and SPECT show evidence of publication bias, implying possible overestimation

Imaging strategies for acute chest pain in the emergency department

OBJECTIVE. Echocardiography, radionuclide myocardial perfusion imaging (MPI), and coronary CT angiography (CTA) are the three main imaging techniques used in the emergency department for the diagnosis of acute coronary syndrome (ACS). The purpose of this article is to quantitatively examine existing evidence about the diagnostic performance of these imaging tests in this setting. CONCLUSION. Our systematic search of the medical literature showed no significant difference between the modalities for the detection of ACS in the emergency department. There was a slight, positive trend favoring coronary CTA. Given the absence of large differences in diagnostic performance, practical aspects such as local practice, expertise, medical facilities, and individual patient characteristics may be more important

Methods for calculating sensitivity and specificity of clustered data: A tutorial

The performance of a diagnostic test is often expressed in terms of sensitivity and specificity compared with the reference standard. Calculations of sensitivity and specificity commonly involve multiple observations per patient, which implies that the data are clustered. Whether analysis of sensitivity and specificity per patient or using multiple observations per patient is preferable depends on the clinical context and consequences. The purpose of this article was to discuss and illustrate the most common statistical methods that calculate sensitivity and specificity of clustered data, adjusting for the possible correlation between observation