Ethnic differences in coronary anatomy, left ventricular mass and CT-derived fractional flow reserve.

BACKGROUND: Studies have observed higher incidence of cardiovascular mortality in South Asians (SA), and lower prevalence in East Asians (EA), compared with Caucasians. These observations are not entirely explained by ethnic differences in cardiovascular risk factors and mechanistic factors such as variations in cardiac anatomy and physiology may play a role. This study compared ethnic differences in CT-assessed left ventricular (LV) mass, coronary anatomy and non-invasive fractional flow reserve (FFRCT). METHODS: Three-hundred symptomatic patients (age 59 ± 7.9, male 51%) underwent clinically-mandated CT-coronary-angiography (CTA) were matched for age, gender, BMI and diabetes (100 each ethnicity). Assessment of coronary stenosis, luminal dimensions and vessel dominance was performed by independent observers. LV mass, coronary luminal volume and FFRCT were quantified by blinded core-laboratory. A sub-analysis was performed on patients (n = 187) with normal/minimal disease (0-25% stenosis). RESULTS: Stenosis severity was comparable across ethnic groups. EA demonstrated less left-dominant circulation (2%) compared with SA (8.2%) and Caucasians (10.1%). SA compared with EA and Caucasians demonstrated smallest indexed LV mass, coronary luminal volumes and dimensions. EA compared with Caucasians had comparable indexed LV mass, coronary luminal dimensions and highest luminal volumes. The latter was driven by higher prevalence of right-dominance including larger and longer right posterior left ventricular artery. FFRCT in the left anterior descending artery (LAD) was lowest in SA (0.87) compared with EA (0.89; P = 0.009) and Caucasians (0.89; P < 0.001), with no difference in other vessels. All observed differences were consistent in patients with minimal disease. CONCLUSION: This single-centre study identified significant ethnic differences in CT-assessed LV mass, coronary anatomy and LAD FFRCT. These hypotheses generating results may provide a mechanistic explanation for ethnic differences in cardiovascular outcomes and require validation in larger cohorts.

Diagnostic accuracy of ASLA score (a novel CT angiographic index) and aggregate plaque volume in the assessment of functional significance of coronary stenosis.

BACKGROUND: Visual assessment of diameter-stenosis on Computed Tomography Coronary Angiography (CTCA) lacks specificity to determine functional significance of coronary artery stenosis. Percent-aggregate plaque volume (%APV) and ASLA score, which incorporates Area of Stenosis, Lesion length, and area of myocardium subtended estimated by APPROACH score (Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease) have been described to predict lesion specific ischaemia in focal lesions with intermediate stenosis. METHODS AND RESULTS: Included were 81 patients (mean age 64.7 ±â€¯9 years, 62% male; 94 vessels) who underwent 320- detector-row CTCA, invasive coronary angiography and fractional-flow-reserve (FFR). We examined vessels with wide range of diameter stenosis (mid to severe) and with multiple lesions. Invasive FFR of ≤0.8 was considered functionally significant. The first 54 patients (62 vessels) formed the derivation cohort. ASLA score was the best predictor of FFR ≤ 0.8 (AUC 0.83, p < 0.001) compared to %APV (0.72), CT >50% (0.76), APPROACH score (0.79), area-stenosis (0.73), diameter-stenosis (0.74), minimum-luminal-diameter (0.74), minimal-luminal-area (0.72), and lesion-length (0.67). ASLA score and not %APV, provided incremental predictive value when added to CT > 50 [(NRI 0.71, p = 0.005) vs. (NRI 0.01, p = 0.96)]. In the validation cohort of 27 patients (32 vessels), the ASLA score (AUC 0.85) was again a better predictor of FFR ≤ 0.8 compared to %APV (0.71), CT > 50% (0.66) and other CT indices. The AUC of ASLA score was superior to CTCA>50% (p = 0.001). CONCLUSION: ASLA score is a novel predictor of functional significance of coronary stenosis and adds incremental predictive value to CT > 50 but %APV did not.

Chronic myeloid leukaemia and tyrosine kinase inhibitor therapy: assessment and management of cardiovascular risk factors.

Several BCR-ABL1 tyrosine kinase inhibitors (TKIs) are approved for the first-line treatment of chronic phase chronic myeloid leukaemia (CML). Disease control is achieved in the vast majority of patients and disease-specific survival is excellent. Consequently, there is now emphasis on managing comorbidities and minimising treatment-related toxicity. Second-generation TKIs have cardiovascular risks that are greater than with imatinib treatment, but these risks must be balanced against the superior CML responses encountered with more potent TKIs. Cardiovascular risk should be assessed at baseline using a locally validated model based on the Framingham risk equation. Clinicians involved in the care of CML patients should be aware of the vascular complications of TKIs and manage cardiovascular risk factors early to mitigate treatment-related risks. Reversible risk factors, such as dyslipidaemia, smoking, diabetes and hypertension, should be addressed. We summarise the available data on cardiovascular complications in CML patients treated with TKIs. Using the latest evidence and collective expert opinion, we provide practical advice for clinicians to assess, stratify and manage cardiovascular risk in people with CML receiving TKI therapy.

Comparison of diagnostic accuracy of combined assessment using adenosine stress computed tomography perfusion + computed tomography angiography with transluminal attenuation gradient + computed tomography angiography against invasive fractional flow reserve.

OBJECTIVES: The goal of this study was to compare the diagnostic accuracy of combined computed tomography perfusion (CTP) + computed tomography angiography (CTA), transluminal attenuation gradient by 320-detector row computed tomography (TAG320) + CTA, and CTP + TAG320 + CTA (multidetector computed tomography-integrated protocol [MDCT-IP]) assessment in predicting significant fractional flow reserve (FFR). BACKGROUND: CTA has limited specificity for predicting functionally significant stenoses. Novel CT techniques, including adenosine stress CTP and TAG320, may improve the diagnostic accuracy of CTA. METHODS: CTA, CTP, and TAG320 were assessed using 320-detector row MDCT. Patients who underwent CTA, CTP, and FFR assessment on invasive coronary angiography were included. CTP was assessed using the visual perfusion assessment. TAG320 was defined as the linear regression coefficient between luminal attenuation and axial distance. A TAG320 cutoff value of -15.1 HU/10 mm as previously described was defined as significant. Functionally significant coronary stenosis was defined as FFR ≤0.8. RESULTS: The cohort included 75 patients (age 64.1 ± 10.8 years, 52 men) and 44 (35%) FFR-significant vessels. In 127 vessels, CTA predicted FFR-significant stenosis with 89% sensitivity and 65% specificity compared with MDCT-IP, which showed 88% sensitivity and 83% specificity. In 97 vessels in which the results of all techniques were available, TAG320 + CTA (area under the curve [AUC] = 0.844) and CTP + CTA (AUC = 0.845) had comparable per-vessel diagnostic accuracy (p = 0.98). The diagnostic accuracy of MDCT-IP (AUC = 0.91) was superior to TAG320 + CTA or CTP + CTA (p = 0.01). CONCLUSIONS: In vessels without significant calcification or artefact, TAG320 + CTA and CTP + CTA provide comparable diagnostic accuracy for functional assessment of coronary artery stenosis. MDCT-IP may provide the best diagnostic accuracy for functional assessment of coronary artery stenosis.

A new algorithm for the management of stable coronary artery disease incorporating CT coronary angiography and fractional flow reserve: how we can improve outcomes and reduce costs.

Computed tomography coronary angiography is the most reliable diagnostic test for coronary atherosclerosis. Stress testing should be reserved for diagnosis of myocardial ischaemia. Revascularisation, either by stenting or bypass grafts, is commonly performed in patients with stable coronary artery disease but is a double-edged sword. In the presence of ischaemia, revascularisation improves outcomes; in its absence, outcomes are worsened. In current practice, the decision of whether to revascularise is mainly made on the basis of the angiographic appearance of the coronary lesion in question. Physiological assessment of coronary lesions by the use of a pressure wire and measurement of fractional flow reserve (FFR) often shows that lesions thought to be sufficiently severe to warrant stenting or bypass do not cause ischaemia. A recent randomised study has shown that using FFR measurements to guide coronary stenting resulted in a lower use of stents, decreased costs and superior outcomes at 2 years, compared with traditional angiographic assessment alone. We believe that changes to the methods of health reimbursement are needed in both the public and private health systems, to facilitate greater use of FFR measurement.