Dual source computed tomography coronary angiography in new onset cardiomyopathy

The Role of Cardiac Computed Tomography in Heart Failure

PURPOSE OF REVIEW

Cardiac computed tomography (CT) is becoming a more widely applied tool in the diagnosis and management of a variety of cardiovascular conditions, including heart failure. The aim of this narrative review is to examine the role of cardiac CT in patients with heart failure.

RECENT FINDINGS

Coronary computed tomographic angiography has robust diagnostic accuracy for ruling out coronary artery disease. These data are reflected in updated guidelines from major cardiology organizations. New roles for cardiac CT in myocardial imaging, perfusion scanning, and periprocedural planning, execution, and monitoring are being implemented. Cardiac CT is useful in ruling out coronary artery disease its diagnostic accuracy, accessibility, and safety. It is also intricately linked to invasive cardiac procedures that patients with heart failure routinely undergo.

Diagnostic accuracy of coronary computed tomography angiography in ischemic workup of heart failure: a meta-analysis

Aim: The role of coronary computed tomography angiography (CCTA) in evaluating the etiology of heart failure with reduced ejection fraction (HFrEF) is unclear. This is a meta-analysis assessing the pooled diagnostic accuracy of CCTA in diagnosing significant coronary artery disease in HFrEF. Materials & methods: Electronic databases were searched for studies comparing CCTA with invasive coronary angiography in HFrEF. A random-effects model meta-analysis was conducted. Results: Five studies comprising 269 patients were included. On patient-based analysis, pooled sensitivity and specificity of CCTA were 0.99 (95% CI: 0.94-1.00) and 0.94 (95% CI: 0.90-0.97), respectively. On segment-based analysis, pooled sensitivity and specificity were 0.74 (95% CI: 0.67-0.80) and 0.99 (95% CI: 0.98-0.99), respectively. Conclusion: CCTA has excellent diagnostic accuracy in diagnosing significant coronary artery disease in newly diagnosed HFrEF.

Mild coronary artery stenosis has no impact on cardiac and vascular parameters in miniature swine exposed to positive acceleration stress

BACKGROUND

Exposure of pilots' heart to acceleration-associated stress (+Gz stress) is an adverse effect of high-performance aviation. The occurrence of coronary heart diseases is one of the most frequent medical causes leading to cessation of flying.

AIM

To assess the effects of +Gz stress on coronary artery stenosis (CAS) in a minimally invasive miniature swine model with a fast recovery.

METHODS

The proximal left anterior descending branch was ligated in 20 swine using silk suture. CAS degree (mild, moderate, severe) was analyzed by quantitative computerized angiography. Five swine underwent a sham operation. +Gz stress exposure was performed and venous blood was collected before/after exposure. Plasma C-reactive protein (CRP), endothelin (ET)-1, angiotensin (Ang) II and urotensin 2 (U2) levels were measured.

RESULTS

CAS models were successful in 18 animals. Two swine exhibited ventricular fibrillation during the procedure and died. Plasma CRP, ET-1, Ang II and U2 changed significantly after maximal tolerated +Gz stress exposure (all P < 0.05). After maximal tolerated +Gz stress exposure, plasma CRP, ET-1, Ang II and U2 levels increased in the moderate and severe stenosis groups, compared with the sham group (all P < 0.05), but there was no significant difference between the mild stenosis group and the sham group (all P > 0.05).

CONCLUSION

The fully endoscopic operation method successfully generated animal models of different degrees of CAS. Plasma CRP, ET-1, Ang II and U2 levels increased after +Gz stress exposure with increasing CAS severity. Animals with mild stenosis showed no ill effect under +Gz stress, suggesting that pilots with mild stenosis might be allowed to continue flying, but it must be confirmed in humans.

Diagnostic accuracy of 64 slice multidetector coronary computed tomographic angiography in left ventricular systolic dysfunction

Background

Detecting coronary artery disease (CAD) is pivotal in etiologic assessment and management of left ventricular (LV) systolic dysfunction. Only a limited number of studies have specifically addressed the accuracy of coronary computed tomographic angiography (CCTA) in detection/exclusion of CAD in patients with LV systolic dysfunction.

Methods

We included patients who were referred for CCTA and invasive coronary angiography within 6 months of each other because of chest pain, either as part of clinical work-up in two Los Angeles medical centers from September 2006 to May 2010 or as part of the multicenter ACCURACY trial. Sensitivity, specificity, positive and negative predictive value, and likelihood ratios of 64 slice multidetector CCTA against coronary angiography were calculated.

Results

Five hundred and thirty-seven patients were included: 228 (42.5%) were women, mean age was 62 ± 12 years, 82 (15.3%) had LV systolic dysfunction (defined by LVEF < 50%). On a patient-based model, the sensitivity of CCTA to detect 50% and 70% coronary lesions was excellent across all LVEF-derived cohorts, ranging from 92% to 100%. The negative predictive value was similarly excellent, ranging from 88% to 100%. CCTA was fairly specific for CAD, with specificity ranging from 83% to 93%, and positive predictive value from 81% to 92%. There was no significant between-group difference for any of the accuracy measures for detecting coronary stenosis at 50% or 70% cutoff.

Conclusion

Sixty-four slice multidetector CCTA is a very sensitive and fairly specific noninvasive diagnostic procedure for detecting coronary stenosis in patients with chest pain regardless of LV systolic function at presentation.

Endoplasmic Reticulum Is Involved in Myocardial Injury in a Miniature Swine Model of Coronary Artery Stenosis Exposed to Acceleration-Associated Stress

This study aimed to investigate the effects of myocardial injury in a minimally-invasive miniature swine model with different levels of coronary artery stenosis (CAS) and exposed to maximal tolerated +Gz. Proximal left anterior descending branch was ligated in 20 swine. Five swine underwent a sham operation. A trapezoid acceleration curve was used for +Gz stress. Pathological changes of myocardial tissue were detected by H&E staining. Apoptotic cardiomyocytes were detected by TUNEL. GRP78 and CHOP were investigated by immunohistochemistry and western blot. CAS models were successful in 18 animals.Compared with the sham-operated group (+8.00±0.71 Gz), the maximal tolerated +Gz values of the moderate stenosis (+6.00±0.89 Gz, P<0.05) and severe stenosis groups (+5.20±0.84 Gz, P<0.05) were decreased.Compared with sham animals (12.16±1.25%), after exposure to maximum +Gz, apoptotic cells of the moderate (43.53±8.42%, P<0.05) and severe stenosis group (60.50±9.35%, P<0.05) were increased, MDA content was increased (1.89 and 4.91 folds, respectively, P<0.05), and SOD activity was reduced (-13.66% and -21.71%, respectively). After exposure to maximum +Gz, GRP78 protein expression was low in the sham-operated (0.29±0.05) and mild stenosis groups (0.35±0.04), while expression was high in the moderate (0.72±0.04, P<0.05) and severe stenosis groups (0.65±0.07, P<0.05). CHOP protein expression was not observed in the sham-operated group, while expression was high in the moderate and severe stenosis groups. These results indicated that Under maximum exposure to +Gz stress, different levels of CAS led to different levels of myocardial injury. Endoplasmic reticulum response is involved in the apoptosis of cardiomyocytes after +Gz stress.