SCOT-HEART trial: reshuffling our approach to stable ischemic heart disease

Comprehensive Non-invasive Versus Invasive Approach to Evaluate Cardiac Allograft Vasculopathy in Heart Transplantation: The CCTA-HTx Study

BACKGROUND

Coronary computed tomography angiography (CCTA) is emerging as a valuable tool for noninvasive surveillance of cardiac allograft vasculopathy (CAV) in patients with heart transplant (HTx). We assessed the diagnostic performance of a comprehensive CCTA-based approach compared with the invasive reference, which includes invasive coronary angiography, intravascular ultrasound, and fractional flow reserve, for detecting CAV.

METHODS

This was a multicenter prospective study including 37 patients with HTx who underwent CCTA, invasive coronary angiography, intravascular ultrasound, and fractional flow reserve. The comprehensive CCTA-based approach included quantitative and qualitative plaque analysis and functional assessment by fractional flow reserve derived from coronary computed tomography. CAV was diagnosed based on invasive coronary angiography (International Society for Heart and Lung Transplantation criteria) and intravascular ultrasound. Univariable logistic regression analysis was performed to test CCTA-derived predictors of CAV. The area under the curve and accuracy indicators were calculated to evaluate the performance and best cutoffs of CCTA predictors of CAV.

RESULTS

The median interval between CCTA and HTx was 5 years. Among the 37 recipients, 23 (62.2%) were diagnosed with CAV. The integration of diameter stenosis and plaque morphology (including plaque burden at minimum lumen area >42% and percent atheroma volume >23%) at CCTA yielded the highest diagnostic performance (accuracy, 84%; sensitivity, 83%; specificity, 86%). The integration of ∆fractional flow reserve derived from coronary computed tomography trans-vessel gradient led to increased sensitivity, albeit with decreased specificity and overall accuracy. The noninvasive approach was associated with a lower contrast and radiation dose, compared with the invasive approach.

CONCLUSIONS

A noninvasive strategy based on CCTA is accurate for managing patients with HTx. CCTA might be considered the preferred imaging modality for annual CAV surveillance after the first year post-HTx.

Cardiac Computed Tomography Angiography in CAD Risk Stratification and Revascularization Planning

PURPOSE OF REVIEW

Functional stress testing is frequently used to assess for coronary artery disease (CAD) in symptomatic, stable patients with low to intermediate pretest probability. However, patients with highly vulnerable plaque may have preserved luminal patency and, consequently, a falsely negative stress test. Cardiac computed tomography angiography (CCTA) has emerged at the forefront of primary prevention screening and has excellent agency in ruling out obstructive CAD with high negative predictive value while simultaneously characterizing nonobstructive plaque for high-risk features, which invariably alters risk-stratification and pre-procedural decision making.

RECENT FINDINGS

We review the literature detailing the utility of CCTA in its ability to risk-stratify patients with CAD based on calcium scoring as well as high-risk phenotypic features and to qualify the functional significance of stenotic lesions.

SUMMARY

Calcium scores ≥ 100 should prompt consideration of statin and aspirin therapy. Spotty calcifications < 3 mm, increased non-calcified plaque > 4 mm3 per mm of the vessel wall, low attenuation < 30 HU soft plaque and necrotic core with a rim of higher attenuation < 130 HU, and a positive remodeling index ratio > 1.1 all confer additive risk for acute plaque rupture when present. Elevations in the perivascular fat attenuation index > -70.1 HU are a strong predictor of all-cause mortality and can further the risk stratification of patients in the setting of a non-to-minimal plaque burden. Lastly, a CT-derived fractional flow reserve (FFRCT) < 0.75 or values from 0.76 to 0.80 in conjunction with additional risk factors is suggestive of flow-limiting disease that would benefit from invasive testing. The wealth of information available through CCTA can allow clinicians to risk-stratify patients at elevated risk for an acute ischemic event and engage in advanced revascularization planning.

The relationship between degree of coronary artery stenosis detected by coronary computed tomography angiography and ACEF risk score in patients with chronic coronary syndrome

BACKGROUND

The ACEF risk score (age, creatinine, and ejection fraction) has been associated with satisfactory predictive values not only for short-term and long-term mortality but also for major adverse cardiovascular events.

OBJECTIVES

Investigate the relationship between ACEF risk score and degree of coronary artery stenosis.

DESIGN

Retrospective, observational study.

SETTING

Tertiary percutaneous coronary intervention center.

PATIENTS AND METHODS

In patients with coronary coronary artery stenosis <70% were compared with patients with stenosis ≥70%. All were diagnosed with chronic coronary syndrome (CCS) and had undergone coronary computed tomography angiography (CTA). Receiver operating characteristic analysis was performed for the cut-off value of the ACEF risk score. Univariable and multivariable regression analyses were performed for significant parameters related to degree of coronary artery stenosis in coronary CTA.

MAIN OUTCOME MEASURES

Relationship between ACEF risk score and degree of coronary artery stenosis in coronary CTA.

SAMPLE SIZE

148 patients.

RESULTS

In the multivariable regression analysis; left ventricular ejection fraction (OR: 0.94; 95%CI: 0.89-0.99, P=.015) and ACEF risk score (OR: 5.63; 95% CI: 1.62-19.57, P=.007) were independent predictors for degree of coronary artery stenosis. The ACEF risk score was statistically significantly higher in with patients with stenosis ≥70% (1.43 [0.59]) than in patients with stenosis <70% (0.98 [0.35]), P<.001). An ACEF risk score value >1.04 was a predictor of the presence of severe coronary artery stenosis detected by coronary CTA in patients with CCS, with 66% sensitivity and 69% specificity.

CONCLUSIONS

A high ACEF risk score (age, creatinine, ejection fraction) in patients with CCS is associated with the presence of severe coronary artery stenosis detected by coronary CTA, and was useful as an assessment tool for coronary angiography in patients with CCS.

LIMITATIONS

Since we do not have long-term follow-up results, we do not know the prognostic value of the ACEF risk score in the long-term follow-up of patients with CCS.

CONFLICT OF INTEREST

None.