Correlation of myocardial perfusion SPECT with invasive and computed tomography coronary angiogram

Coronary Artery Disease in Patients with Ischemic Stroke and TIA

BACKGROUND AND OBJECTIVES

Ischemic stroke (IS) and coronary artery disease (CAD) share common risk factors and one may be the harbinger of the other. We aimed to study prevalence of symptomatic and asymptomatic CAD in a cohort of consecutive patients with IS and assess its relationship with intracranial and extracranial large artery cerebrovascular disease (LAD).

METHODS

All consecutive eligible IS and Transient Ischemic Attack (TIA) patients were recruited into the study. Both clinically suspected and asymptomatic patients (N = 259) underwent myocardial Stress-rest Gated Technetium-99m (Tc99m) MIBI Myocardial Perfusion SPECT scan performed on a dual head SPECT-CT to estimate evidence of myocardial ischemia.

RESULTS

Three hundred patients completed the study. Forty one patients were previously diagnosed cases of definitive CAD. Twelve patients were clinically suspected to have CAD and 247 patients were asymptomatic. Among these, 12 patients (4.81%) had a positive SPECT. The overall prevalence of CAD was 17.67% (n = 53). Presence of diabetes was an independent predictor of CAD (OR 1.98, 95% CI 1.07-3.67. P .02). No significant association was found between the presence of LAD and CAD in all subgroup comparisons. However, there was a suggestion of higher LAD among patients with known CAD compared with others.

CONCLUSIONS

CAD is prevalent in patients with ischemic stroke. No definitive relationship was found between CAD and intracranial or extracranial LAD. Population based stratification tools are needed to further assess the need to detect subclinical CAD in patients with stroke.

The Concordance between Myocardial Perfusion Imaging and Coronary Angiography in Detecting Coronary Artery Disease: A Retrospective Study in a Tertiary Cardiac Center at King Abdullah Medical City

Background. Coronary artery disease (CAD) is considered as the leading cause of the cardiovascular fatalities worldwide. CAD is diagnosed by many modalities of imaging such as myocardial perfusion imaging (MPI) and coronary angiography (CAG). Methods. A retrospective cross-sectional study was conducted that included all patients referred to the KAMC (King Abdullah Medical City) nuclear cardiology lab from its opening until the end of May 2014 (a period of 17 months). A total of 228 patient reports with a history of conducting either CAG or MPI or both were used in this study and statistically analyzed. Results. An analysis of the MPI results revealed that 78.5% of the samples were abnormal. On the other hand, 26.75% of the samples revealed that they were subjected to CAG and MPI. There was a significant and fair agreement between MPI and CAG by using all the agreement coefficients (kappa = 0.237, phi = 0.310, and P value = 0.043). The sensitivity, specificity, and accuracy of MPI with reference to CAG were 97.8%, 20%, and 78.69%, respectively. In addition, positive predictive and negative predictive values were 78.95% and 75%, respectively. Conclusion. In a tertiary referral center, there was a significant agreement between MPI and CAG and a high accuracy of MPI. MPI was a noninvasive diagnostic test that could be used as a gatekeeper for CAG.

Effect of heart rate on the diagnostic accuracy of 256-slice computed tomography angiography in the detection of coronary artery stenosis: ROC curve analysis

The aim of the present study was to investigate the effect of heart rate (HR) on the diagnostic accuracy of 256-slice computed tomography angiography (CTA) in the detection of coronary artery stenosis. Coronary imaging was performed using a Philips 256-slice spiral CT, and receiver operating characteristic (ROC) curve analysis was conducted to evaluate the diagnostic value of 256-slice CTA in coronary artery stenosis. The HR of the research subjects in the study was within a certain range (39-107 bpm). One hundred patients suspected of coronary heart disease underwent 256-slice CTA examination. The cases were divided into three groups: Low HR (HR <75 bpm), moderate HR (75≤ HR <90 bpm) and high HR (HR ≥90 bpm). For the three groups, two observers independently assessed the image quality for all coronary segments on a four-point ordinal scale. An image quality of grades 1-3 was considered diagnostic, while grade 4 was non-diagnostic. A total of 97.76% of the images were diagnostic in the low-HR group, 96.86% in the moderate-HR group and 95.80% in the high-HR group. According to the ROC curve analysis, the specificity of CTA in diagnosing coronary artery stenosis was 98.40, 96.00 and 97.60% in the low-, moderate- and high-HR groups, respectively. In conclusion, 256-slice coronary CTA can be used to clearly show the main segments of the coronary artery and to effectively diagnose coronary artery stenosis. Within the range of HRs investigated, HR was found to have no significant effect on the diagnostic accuracy of 256-slice coronary CTA for coronary artery stenosis.