Is coronary computed tomographic angiography the “gold standard” for coronary artery disease?

Diagnostic accuracy of computed tomography coronary angiography utilizing recent advances in technology in patients with high heart rates: a systematic review protocol

OBJECTIVE

The objective of this review is to determine the diagnostic accuracy of computed tomography coronary angiography (CTCA) using recent scan technologies for detecting coronary artery disease (CAD) in adults with high heart rates.

INTRODUCTION

Invasive coronary angiography is the gold standard for detecting significant CAD, but it is costly and carries risks of complications. Computed tomography coronary angiography has a high sensitivity for diagnosing CAD, although image quality may be affected by elevated heart rates. Recent technological advances in scanner design may increase the diagnostic accuracy of CTCA.

INCLUSION CRITERIA

This review will consider diagnostic test accuracy studies that include adults 18 years and older with a heart rate greater than 65 beats per minute who have undergone CTCA to diagnose CAD (greater than 50% stenosis). Eligible studies will compare invasive coronary angiography with computed tomography scanner technologies that use either single- or dual-source scanner configuration in prospective electrocardiogram scan acquisition mode, and with a total scanner coverage equal to or greater than 128 detector-rows. Studies published in English from 2007 will be considered.

METHODS

PubMed, Embase, CINAHL and Scopus will be searched, along with Google Scholar, the NIHR-HTA register, computed tomography vendors and conference abstracts. Screening of potential titles and abstracts, retrieval of full-text studies, assessment of methodological quality and data extraction will be performed independently by two reviewers. Meta-analyses will be performed, if possible, and a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) Summary of Findings presented.

The potential value of hybrid positron emission tomography/dual-source computed tomography imaging in coronary bypass surgery

BACKGROUND

We evaluated how comprehensive assessment of coronary artery lesions and their hemodynamic relevance by means of hybrid positron emission tomography (PET) and computed tomography (CT) imaging would affect decision-making in coronary artery bypass surgery (CABG), compared with using invasive coronary angiography (ICA) alone.

METHODS

After undergoing ICA, 27 patients (21 men and 6 women; mean SD age, 66 ± 10 years) planned for cardiac surgery were scheduled for myocardial perfusion stress/rest evaluation with [13N]ammonia PET and CT coronary angiography. Only ICA was available to the surgeon. Postoperatively, the performed CABG was compared with the hypothetical strategy based on hybrid PET/CT findings (regional coronary flow reserve [CFR], myocardial perfusion defects). Procedures included CABG (n = 18) alone, CABG combined with valve replacement (n = 6), and CABG combined with isolated valve replacement (n = 3). A total of 56 bypass grafts (28 venous and 28 arterial) and 66 distal anastomoses were placed.

RESULTS

CT evaluation showed 93% concordance (66/71) with ICA regarding significant stenoses, with sensitivity, specificity, positive predictive value, and negative predictive value of 93.1%, 98.7%, 94.4%, and 98.4%, respectively. In the PET scan, 16 patients had 1 ischemic region, and 12 patients had 1 scar region, including 5 patients who presented with mixed conditions (scar and ischemia). One patient had a completely normal myocardium. Compared with the performed surgery, PET/CT fusion evaluation showed that of the performed anastomoses, 48% had documented ischemia (with a CFR <2 in 86%), 38% were nonischemic (although a CFR value <2 was found in 78%), and 14% had scar tissue (fixed perfusion defect).

CONCLUSIONS

Although <50% of bypasses were placed to areas with myocardial ischemia, the CFR was low in the majority of nonischemic regions, a finding that may have important prognostic relevance. PET/CT fusion imaging could potentially influence planning for CABG and provide incremental prognostic information.

Coronary CT angiography in Takayasu arteritis

OBJECTIVES

The aim of this study was to use coronary computed tomographic (CT) angiography to characterize coronary artery involvement in patients with known Takayasu arteritis who present with anginal chest pain or shortness of breath.

BACKGROUND

Takayasu arteritis is a primary vasculitis of the large vessels, which mainly affects the aorta and its branches but can also involve the coronary arteries. Coronary CT angiography allows visualization of the coronary vessels and can be used to detect both stenotic and nonstenotic coronary artery lesions.

METHODS

Eighteen consecutive patients with Takayasu arteritis and angina (typical or atypical) and/or dyspnea underwent contrast-enhanced 64-slice coronary CT angiography. The arterial injury was classified according to the Numano classification. Three patients had prior known coronary artery disease. Coronary arteries were evaluated concerning the presence of obstructive and nonobstructive lesions, and differences between the clinical presentations of patients with and without coronary artery involvement on CT angiography were analyzed.

RESULTS

Coronary artery involvement was found in 8 patients (44.4%), 3 of them with clinical activity. A total of 19 coronary lesions were present (13 in ostial locations, 5 in proximal coronary artery segments, and 1 in a mid segment). Eight lesions exceeded 50% diameter reduction (2 in ostial locations and 6 in proximal coronary artery segments). Median disease duration was significantly different between patients with coronary artery involvement (176 months; range 13 to 282 months) compared with those without (21 months; range 1 to 142 months) (p = 0.013).

CONCLUSIONS

Coronary CT angiography allows the assessment of coronary artery involvement in patients with Takayasu arteritis. These data confirm prior observations that most coronary lesions are in ostial or proximal coronary artery locations. Disease duration in patients with coronary artery involvement is longer than in patients without.