Wynand J. Stuijfzand

Comparison of Coronary CT Angiography, SPECT, PET, and Hybrid Imaging for Diagnosis of Ischemic Heart Disease Determined by Fractional Flow Reserve

Importance At present, the choice of noninvasive testing for a diagnosis of significant coronary artery disease (CAD) is ambiguous, but nuclear myocardial perfusion imaging with single-photon emission tomography (SPECT) or positron emission tomography (PET) and coronary computed tomography angiography (CCTA) is predominantly used for this purpose. However, to date, prospective head-to-head studies are lacking regarding the diagnostic accuracy of these imaging modalities. Furthermore, the combination of anatomical and functional assessments configuring a hybrid approach may yield improved accuracy. Objectives To establish the diagnostic accuracy of CCTA, SPECT, and PET and explore the incremental value of hybrid imaging compared with fractional flow reserve. Design, Setting, and Participants A prospective clinical study involving 208 patients with suspected CAD who underwent CCTA, technetium 99m/tetrofosmin–labeled SPECT, and [15O]H2O PET with examination of all coronary arteries by fractional flow reserve was performed from January 23, 2012, to October 25, 2014. Scans were interpreted by core laboratories on an intention-to-diagnose basis. Hybrid images were generated in case of abnormal noninvasive anatomical or functional test results. Main Outcomes and Measures Hemodynamically significant stenosis in at least 1 coronary artery as indicated by a fractional flow reserve of 0.80 or less and relative diagnostic accuracy of SPECT, PET, and CCTA in detecting hemodynamically significant CAD. Results Of the 208 patients in the study (76 women and 132 men; mean [SD] age, 58 [9] years), 92 (44.2%) had significant CAD (fractional flow reserve ⩽0.80). Sensitivity was 90% (95% CI, 82%-95%) for CCTA, 57% (95% CI, 46%-67%) for SPECT, and 87% (95% CI, 78%-93%) for PET, whereas specificity was 60% (95% CI, 51%-69%) for CCTA, 94% (95% CI, 88%-98%) for SPECT, and 84% (95% CI, 75%-89%) for PET. Single-photon emission tomography was found to be noninferior to PET in terms of specificity (P < .001) but not in terms of sensitivity (P > .99) using the predefined absolute margin of 10%. Diagnostic accuracy was highest for PET (85%; 95% CI, 80%-90%) compared with that of CCTA (74%; 95% CI, 67%-79%; P = .003) and SPECT (77%; 95% CI, 71%-83%; P = .02). Diagnostic accuracy was not enhanced by either hybrid SPECT and CCTA (76%; 95% CI, 70%-82%; P = .75) or by PET and CCTA (84%; 95% CI, 79%-89%; P = .82), but resulted in an increase in specificity (P = .004) at the cost of a decrease in sensitivity (P = .001). Conclusions and Relevance This controlled clinical head-to-head comparative study revealed PET to exhibit the highest accuracy for diagnosis of myocardial ischemia. Furthermore, a combined anatomical and functional assessment does not add incremental diagnostic value but guides clinical decision-making in an unsalutary fashion.

Incremental diagnostic value of epicardial adipose tissue for the detection of functionally relevant coronary artery disease

BACKGROUND AND AIM To determine the incremental diagnostic value of epicardial adipose tissue (EAT) volume in addition to the coronary artery calcium (CAC) score for detecting hemodynamic significant coronary artery disease (CAD). METHODS AND RESULTS 122 patients (mean age 61 ± 10 years, 61% male) without a previous cardiac history underwent a non-contrast CT scan for calcium scoring and EAT volume measurements. Subsequently all patients underwent invasive coronary angiography (ICA) in conjunction with fractional flow reserve (FFR) measurements. A stenosis >90% and/or a FFR ≤0.80 were considered significant. Mean EAT volume and CACscore were 128 ± 51 cm(3) and 418 ± 704, respectively. The correlation between EAT volume and the CACscore was poor (r = 0.11, p = 0.24). Male gender (odds ratio [OR] 2.86, p = 0.01), CACscore ([cut-off value 100] OR 3.31, p = 0.003, and EAT volume ([cut-off value 92 cm(3)] OR 4.28, p = 0.01) were associated with flow-limiting disease. The multivariate model revealed that only male gender (OR 2.50, p = 0.045), CAC score (OR 3.60, p = 0.005), and EAT volume (OR 4.95, p = 0.02) were independent predictors of myocardial ischemia. Using the cut-off values of 100 (CAC score) and 92 cm(3) (EAT volume), sensitivity, specificity, negative predictive value, positive predictive value, and accuracy for detecting functionally relevant CAD as indicated by FFR were 71, 57, 77, 50 and 63% and 91, 29, 85, 44 and 52% for the CACscore and EAT volume, respectively. Adding EAT volume to the CAC score and cardiovascular risk factors did not enhance diagnostic performance for the detection of significant CAD (p = 0.57). CONCLUSION EAT volume measurements have no diagnostic value beyond calcium scoring and cardiovascular risk factors in the detection of hemodynamic significant CAD.

Effects of successful percutaneous coronary intervention of chronic total occlusions on myocardial perfusion and left ventricular function

AIMS The aim of the present study was to investigate the effects of successful PCI CTO on absolute myocardial blood flow (MBF) and functional recovery. METHODS AND RESULTS Patients with a documented CTO were prospectively examined for ischaemia and viability with [15O]H2O positron emission tomography (PET) and late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMR). Sixty-nine consecutive patients, in whom PCI was successful, underwent follow-up PET and CMR after approximately 12 weeks to evaluate potential improvement of MBF as well as systolic function. After PCI, stress MBF in the CTO area increased from 1.22±0.36 to 2.40±0.90 mL·min-1·g-1 (p<0.001), whilst stress MBF in the remote area also increased significantly between baseline and follow-up PET (2.58±0.68 to 2.77±0.77 mL·min-1·g-1, p=0.01). The ratio of stress MBF between CTO and remote area was 0.49±0.13 at baseline and increased to 0.87±0.24 at follow-up (p<0.001). The MBF defect size of the CTO area decreased from 5.12±1.69 to 1.91±1.75 myocardial segments after PCI (p<0.001). Left ventricular ejection fraction (LVEF) increased significantly (46.4±11.0 vs. 47.5±11.4%, p=0.01) at follow-up. CONCLUSIONS The vast majority of CTO patients with documented ischaemia and viability showed significant improvement in stress MBF and a reduction of ischaemic burden after successful percutaneous revascularisation with only minimal effect on LVEF.

Antegrade wire escalation for chronic total occlusions in coronary arteries: simple algorithms as a key to success.

Aims Antegrade wire escalation (AWE) remains the method of choice for tackling chronic total occlusions (CTOs), especially for lesions with low J-CTO score. To increase the number of operators which treat CTOs and increase AWE success rates, there is a need for a clear, algorithmic approach. We report the results of a simple AWE algorithm with new guidewire technology in coronary CTOs. Methods Hundred consecutive CTO lesions selected for AWE as the primary strategy were included in five Benelux centers. The algorithm follows a step-wise increase in guidewire tip load. Lesions were categorized according to the J-CTO score. Primary endpoint was successful guidewire crossing. Results No differences in baseline demographics were present between successful and unsuccessful procedures. Overall, in 75% of the lesions AWE resulted in successful crossing. AWE success rates in easy, intermediate, difficult and very difficult CTOs were 83, 86, 71 and 43%, respectively. 46% could be crossed using a soft guidewire only. An additional success of 34 and 60% could be reached with an intermediate and stiff guidewire, respectively. Adding additional techniques resulted in 88% overall success. Procedure and fluoroscopy times, radiation doses and use of contrast were within highly acceptable ranges (67 ± 39 min, 27 ± 19 min, 1.7 ± 1.3 Gy, 264 ± 123 ml). Conclusion The algorithm and new wire technologies led to high success rates. AWE as a standalone procedure is highly successful in J-CTO 0-1. Low- and intermediate-volume CTO operators should try to implement a systematic approach in their CTO procedures, especially for lesions with low J-CTO scores. Adding additional techniques further increases these success rates.

Incremental Value of Hybrid PET/CT in Patients with Coronary Artery Disease

The noninvasive diagnosis of coronary artery disease (CAD) is a challenging task. Traditionally, myocardial perfusion imaging (MPI) has been widely used for this purpose whereby cardiac positron emission tomography (PET) is considered the gold standard. Alternatively, noninvasive anatomical imaging of coronary atherosclerosis with coronary computed tomography angiography (CCTA) has recently been successfully implemented in clinical practice. Cardiac hybrid imaging consists of the fusion of these modalities and provides detailed information on the presence and extent of CAD including its functional consequences on myocardial perfusion. This type of comprehensive imaging, obtained within a single session using a PET/CT scanner, appears to have superior diagnostic and prognostic value as compared with either stand-alone test. This review discusses the literature on the incremental value of hybrid cardiac PET/CT imaging for patients suspected of CAD.

Impact of right ventricular side branch occlusion during percutaneous coronary intervention of chronic total occlusions on right ventricular function

OBJECTIVE To determine the impact of right ventricular side branch (RVB) occlusion, during percutaneous coronary interventions (PCIs) of chronic total occlusions (CTOs) of the right coronary artery (RCA), on right ventricular (RV) function. BACKGROUND Developments in PCI techniques have expanded PCI CTO feasibility. However, the utilization of dissection and reentry techniques and extensive stent implantation increases the risk of coronary side branch occlusion. METHODS Fifty-four patients (80% male, 63±10years) evaluated with cardiac magnetic resonance imaging (CMR) prior and three months after successful PCI CTO RCA (median: 99days, IQR: 92-105days) were included. Right ventricular end-diastolic volume (RVEDV), end-systolic volume (RVESV), and ejection fraction (RVEF) were quantified on CMR images. Occurrence of RVB occlusion and/or RVB recruitment was assessed using procedural angiograms. RESULTS RVB occlusion was observed in 12 patients (22%), while RVB recruitment occurred in seven patients (13%). Overall, RVEF was comparable between baseline and follow-up (53.8±5.8 vs. 53.9±5.8%, p=0.95). RVB occlusion was not associated with a significant change in RVEDV or RVEF (156.9±36.3 vs. 162.1±35.5mL, p=0.30 and 54.2±3.9 vs. 52.7±4.4%, p=0.19, respectively); however a trend was observed for an increase of RVESV (72.5±20.0 vs. 77.4±20.7mL, p=0.05) at follow-up. RVB recruitment did not result in a significant improvement of RVEF (55.4±4.6 vs. 56.1±5.3%, p=0.75). CONCLUSION RVB occlusion was not associated with a significant decreased RVEF at follow-up, although the results suggested a limited increase of RVESV.